IAC Module 3v2

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@@.whitetext; !!!Virtual Anaesthetics_3 Welcome to the third in a series of interactive scenarios to support learning during the IAC. You can find out more on using this scenario ''[[here|howtoguide]]''. ''Disclaimer: Virtual Anaesthetics is not responsible for your use of the information contained in or linked from this site. All users should act within their own competence and according to local and national guidelines and policies. All treatment information contained herein is provided as a general example only and you should always check drug doses in an appropriate formulary. Any descriptions of procedures or techniques is intended as an example only and as a supplement formal training. Individuals should only perform procedures or techniques they have been formally trained in and are competent to perform.'' @@ ''[[Next|Introduction]]'' [[I'm a clinical supervisor or trainer|trainers_area]] @@.whitetext; If you are ''not'' a health care professional please read our brief message first [[here|message]]@@

/* <<countdownTimer>> Widget - Start */ <<widget "countdownTimer">> <<set _seconds = $args[0]>> <<set _minutes = Math.floor(_seconds / 60)>> <<set _replacementPassage = $args[1]>> <div id="timer" class="timergreen">Time remaining _minutes:<<= (_seconds - (_minutes * 60)).toString().padStart(2, '0')>></div><<script>> if (!recall("countdown", undefined)) { setup.countdown = { startTime: new Date(), lastStr: "", passage: passage() }; memorize("countdown", setup.countdown); } else { setup.countdown = recall("countdown"); if (setup.countdown.passage !== passage()) { setup.countdown = { startTime: new Date(), lastStr: "", passage: passage() }; memorize("countdown", setup.countdown); } } setup.countdown.intervalID = setInterval(function () { if (setup.countdown.passage !== passage()) { clearInterval(setup.countdown.intervalID); forget("countdown"); setup.countdown.passage = ""; } else { var curtime = new Date(), str, seconds = State.temporary.seconds; var diff = Math.floor(seconds - ((curtime - setup.countdown.startTime) / 1000)), min = Math.floor(diff / 60); if ((diff >= 0) && (diff < seconds)) { if ($("#timer").length) { str = "Time remaining " + min + ":" + (diff - (min * 60)).toString().padStart(2, '0'); if (str != setup.countdown.lastStr) { $("#timer").empty().wiki(str); setup.countdown.lastStr = str; } if (diff <= 10) { if (!$("#timer").hasClass("timerred")) { $("#timer").removeClass("timeramber").addClass("timerred"); } } else if (diff <= 20) { if (!$("#timer").hasClass("timeramber")) { $("#timer").removeClass("timergreen").addClass("timeramber"); } } } } if (diff < 0) { clearInterval(setup.countdown.intervalID); forget("countdown"); $("#passages div.passage").empty().wiki('<<include "' + State.temporary.replacementPassage + '">>'); delete setup.countdown.passage; } } }, 200); <</script>> <</widget>> /* <<countdownTimer>> Widget - End */

@@.whitetext; !!!Virtual Anaestheics_3: Emergencies & emergence Enter your first name: <<textbox "$firstname" "">> Enter your surname: <<textbox "$surname" "">> <<set $role = ["-", "Stage 1 Anaesthetist in Training", "Stage 2 Anaesthetist in Training", "Stage 3 Anaesthetist in Training", "Consultant Anaesthetist", "Associate Specialist Anaesthetist", "Speciality Doctor Anaesthetist", "Foundation Doctor", "Doctor (Other)", "Medical Student", "Other health care professional", "Role outside healthcare"]>>''Select your professional role:'' <<listbox "$role">> <<optionsfrom $role>> <</listbox>> <<set $randomid to random(10000000,99999999)>> <<nobr>><span id="ReplaceMe"> <<link "''Next''">> <<script>> Dialog.setup("Analytics"); Dialog.wiki("Users' privacy and data protection are our priorities. Virtual Anaesthetics uses analytics and collects anonymised data to improve your service and provide academic governance including passage function, anonymised scores, playtime, and any feedback comments you provide. This anonymised data may also be used in part or in its entirety for research and publication. For more information on our privacy policy please see ''[[here|https://www.virtualanaesthetics.com/privacy-policy/]]''. Please also be aware that this information is temporarily stored in your local internet browser cache. If using a public or shared computer you can avoid this by clearing your internet history and website data on competition of the scenario."); Dialog.open(); <</script>> <<replace "#ReplaceMe">> ''[[Next|Core clinical learning objectives]]''<br> <</replace>> <</link>></span><</nobr>>

<<cacheaudio "text" "audio/text.mp3">> <<cacheaudio "monitorslow" "audio/monitorslow.mp3">> <<cacheaudio "monitorfast" "audio/monitorfast.mp3">> <<cacheaudio "monitorgofast" "audio/monitorgofast.mp3">> <<cacheaudio "monitorgoslow" "audio/monitorgoslow.mp3">> <<cacheaudio "monitor" "audio/monitor.mp3">> <<cacheaudio "emergency" "audio/emergency.mp3">> <<cacheaudio "postarrest" "audio/postarrest.mp3">> <<set $history to []>> <<set $started to 0>>

!!!@@.greentext; Scenario learning objectives:@@ * Have a working knowledge of the emergency drugs they would have ready for use * Experience decision making under pressure * Know how to access the A Quick Reference Handbook and apply the guidance to a common anaesthetic ‘emergency’ * Consider where to access sources of support within their own work setting * Understand the importance of using a peripheral nerve stimulator when using neuromuscular blocking drugs * Have discussed how they would manage extubation in a low risk patient using the DAS extubation guidelines @@.greentext; ''For optimal interaction this module is better on a larger screen device <u>with an unmuted speaker</u>. If you're starting here we recommend having a look at Virtual Anaesthetics_1 and 2 first which provide background knowledge and platform familiarity which is useful, but not essential, for Virtual Anaesthetics_3.''@@ [[Next->theatre1]] <<audio "monitor" pause>> [[Show me the EPA for IAC mapped to this scenario|epa]] [[Show me the stage 1 curriculum|stage1]]

!!!@@.greentext;Scenario learning objectives:@@ * Have a working knowledge of the emergency drugs they would have ready for use * Experience decision making under pressure * Know how to access the AAGBI Quick Reference Handbook and apply the guidance to a common anaesthetic ‘emergency’ * Consider where to access sources of support within their own work setting * Understand the importance of using a peripheral nerve stimulator when using neuromuscular blocking drugs * Have discussed how they would manage extubation in a low risk patient using the DAS extubation guidelines ''Printable evidence for the LLP'' ''[[here|https://www.virtualanaesthetics.com/IACModule%203/IACmodule3mapped.pdf]]'' [[Credits and certificate|credits]] <<set $historyOutput to "">> <<nobr>> <<set _last to $started>> <<for _event range $history>> <<set $historyOutput to $historyOutput + "<br>Passage: " + _event.passage + ", Seconds: " + setup.toSeconds(_last, _event.time)>> <<set _last to _event.time>> <</for>> <</nobr>> <<nobr>> <<set $passagetimes to $historyOutput>> <<set $id to "VA3IAC">> <<set $result1 to "-">> <<set $result2 to "-">> <<set $playtimehr to playTime('hours')>> <<set $playtimemin to playTime('minutes')>> <<set _data = {randomid: $randomid, role: $role, id: $id, playtimehr: $playtimehr, playtimemin: $playtimemin, result1: $result1, result2: $result2, passagetimes: $passagetimes }>> <<run sendData4(_data)>> <</nobr>>

<center> @@.whitetext; ''With thanks to everyone who helped make this scenario happen!'' Our actors: Emilia Powell, Matt Healey, & Richard Wassall Filming: Larisa Alexandra Research: Cameron Whytock Our tech support: Charlie Hargood and Louis Rose Our logistical support: Patrick Wainwright Our editorial team: Fiona Martin, Rachael Hopper and Oliver Pratt Our creative director and lead programmer: Kate Wainwright !!!Well done for completing Virtual Anaesthetics_3 <<nobr>><span id="ReplaceMe"> <<link "''certificate''">> <<script>> Dialog.setup("Tell us"); Dialog.wiki("<center> <h3>@@.greentext;You can make Virtual Anaesthetics better. <br><br>Tell us what you think of this scenario [[here|https://forms.gle/QjzbkPQPd5vttkBS7]]. It should take less than a minute. <br><br>Thanks!@@</h3> </center>"); Dialog.open(); <</script>> <<replace "#ReplaceMe">> ''[[certificate]]''<br> <</replace>> <</link>></span><</nobr>> @@ </center>

# Cook T, Woodall N, Frerk C. Major complications of airway management in the UK: results of the Fourth National Audit Project of the RCoA & The Difficult Airway Society. //BJA//. 2011; 106(5):617-31 [[Back|theatre11]]

<p style="text-align:justify">Hang on...what? You turn to look at the anaesthetic machine. <center> <img src="images/brady.jpg" style="max-width: 500px;"/> </center> As the ECG trace undulates its way from the left to the right of the screen you see a long expanse of nothing. The ECG heart rate is flashing 41...34...30...30...30 No one is looking at the laparoscope screen now. They’re looking at the monitor, and then at you. What's going on? The bradycardia could be due to...</p> [[...a drug error|theatre3][$brady = "Not quite"]] [[...a drug side effect|theatre3][$brady = "Not quite"]] [[...the surgical stimulus|theatre3][$brady = "Not quite"]] [[...the pneumoperitoneum|theatre3][$brady = "Not quite"]] [[...high intrathoracic pressure|theatre3][$brady = "Not quite"]] [[...any of the above|theatre3][$brady = "Correct"]] <<audio "monitor" pause>> <<audio "monitorslow" volume 0.5 loop play>> <<set $brady2 to "No answer given">> <<timed 59s>> <<goto arrest>> <</timed>> <<countdownTimer 60 "arrest">>

<p style="text-align:justify">You glance at the clock on the wall in theatre. It's 09:16 on a Monday and you are doubled up with consultant anaesthetist Dr Henry Coal on an upper GI list. He is supervising from the office across the hall so you can do this anaesthetic with Paul the ODP. The patient, Lisa Redbridge, is ASA II, and undergoing a laparoscopic cholecystectomy. Her induction has gone smoothly and you have just moved through from the anaesthetic room into theatre. You look at the monitor. Everything seems pretty good. "Happy for me to start?" Neil asks. "Yes, thanks." The first port goes in. The lights go down. "Right, insufflate to 14." Neil is looking at the screen on the laparoscope stack now. Everyone in theatre is. You recognise the smooth dome of the liver edge rising up into the picture.</p> [[Next|theatre2]] <<audio "monitor" volume 0.5 loop play>> <<audio "monitorslow" pause>> <<set $brady to "No answer given">>

<center> [[Transcript->transcript]]      [[Next->videopost]] <iframe width="100%" height="600" src="https://www.youtube.com/embed/wEJClBaOdDE" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe> </center>

@@.typing;''"Ok, so we’ve finished the case so lets get this tube out."'' ''"Ready to take that off."'' //Turns off volatile// ''"Turn that to 100% oxygen."'' //Turns O~~2~~ to 100%// ''"Brilliant. Right then, so, we’ve positioned her appropriately."'' //Patient is semi recumbent on theatre trolley// ''"Let's see if we need to give any reversal. Let's check the train of four."'' //Patient’s hand jerks four times// ''"We’ve got a little bit of fade there. So lets just give our reversal. OK."'' //Gives reversal agent into cannula on back of patient's hand// ''"Excellent we’ll check that in a minute."'' ''"Switch this onto manual."'' //Leans over and switches from ventilator to manual ventilation on anaesthetic machine// ''"And see what we get."'' //Close up ventilator screen showing small tidal volume breaths// ''"Ok then, little bit of breathing, excellent, sure that will improve once the reversal gets going."'' ''"OK, everything looks ok, we’ve got a bite block in just so we’ve got some extra protection."'' ''"Are we going to loosen this?"'' //Unties tube tie bow at side of patient's mouth// ''"OK lets see what her breathing is like, so that’s excellent we just need to wait for the gas to go down and then she should be waking up very soon."'' ''"Let's check the train of four again."'' //Patient’s hand jerks four times, more vigorously than before// ''"Ok we’ll just take this off."'' //Removes peripheral nerve stimulator from right ulnar nerve// ''"Perfect."'' //Louder voice to patient:// ''"Hello, you’re just waking up, operation's all over, you’re just waking up, take some nice slow deep breaths for me, you’re doing really well now."'' //Monitor close up showing larger tidal volumes// ''"Little bit of suction."'' //Superficial suctions side of mouth// //Louder voice to patient:// ''"Ok open your eyes, operation's all over, that’s it, take some slow deep breaths for me."'' //To ODP:// ''"Just apply a little bit of PEEP, and we will cuff down please, excellent."'' //Louder voice to patient: // ''"You’re just waking up, take some nice slow deep breaths, stick your tongue out for me."'' //Removed ETT in smooth motion.// //Louder voice to patient:// ''"Well done, well done."'' //To ODP:// ''"Just pop the oxygen mask on, perfect."'' //Louder voice to patient:// ''"There we are, take some slow deep breaths, you’re doing really well, got some good breathing, excellent."'' //Mask falls off circuit and is replaced//. ''"You’re doing really well."'' //To ODP:// ''"We’ll pop an oxygen mask on and then she’s fine to go to recovery. Could someone ring them please and let them know that we’re coming? Thank you."''@@ <center> [[Play video|video]]    [[Next|videopost]] </center>

You walk Lisa down to recovery and give the staff a comprehensive handover. The rest of the list is thankfully uneventful. [[Next|email]]

@@.typing;''From:'' Henry Coal ''To:'' $firstname $surname ''Subject:'' Re: today's list Hi $firstname Thanks for your consistent effort today. What with one thing and another, that was a complicated list. Keep up the good work you will continually improve. Well done. Henry Dr Henry Coal MBChB, MA, FRCA Consultant in Anaesthesia @@ [[End]] Sent from my iPad

<<print $brady>>. <p style="text-align:justify">Neil has just insufflated so the pneumoperitoneum may be the most likely cause but you don’t want to miss something by dismissing alternative causes. Everyone is still looking at you. While part of your brain is quickly running through what the most likely cause of this bradycardia is, the other part is rapidly thinking of the next action you have to take. What are you going to do first?</p> [[Check BP|theatre4][$brady2 = "Not quite"]] [[Check for pulse|theatre4][$brady2 = "Not quite"]] [[Get help|theatre4][$brady2 = "Correct"]] [[Stop surgical stimulus|theatre4][$brady2 = "Not quite"]] [[Check rhythm|theatre4][$brady2 = "Not quite"]] [[Give 1ml 1:10,000 adrenaline|theatre4][$brady2 = "Not quite"]] [[Give 300-600 µg atropine|theatre4][$brady2 = "Not quite"]] [[Give 200-400 µg glycopyrrolate |theatre4][$brady2 = "Not quite"]] <<set $brady3 to "No answer given">> <<timed 59s>> <<goto arrest>> <</timed>> <<countdownTimer 60 "arrest">>

<<print $brady2>>. You want to get help on the way. <p style="text-align:justify">You look across to Marion the HCA who just happens to be right next to the emergency buzzer. "Marion. Pull the emergency buzzer please." It feels like slow motion as you watch her turn to the wall and do it. That seems to spur the room into action. Neil is letting the pneumoperitoneum off. Shirley is scrubbed and protectively moves the tables of sterile instruments sideways to make space for help when it arrives. You press the BP to cycle and reach to the top of the anaesthetic machine for the tray of emergency drugs. <center> <img src="images/emerg.jpg" style="max-width: 400px;"/> </center> What do you want to give first?</p> [[300-600 µg atropine|theatre5][$brady3 = "Correct"]] [[200-400 µg glycopyrrolate|theatre5][$brady3 = "Correct"]] [[500 µg metaraminol|theatre5][$brady3 = "Not quite"]] [[3-6 mg ephedrine|theatre5][$brady3 = "Not quite"]] <<audio "monitorgofast" pause>> <<audio "monitorslow" volume 0.5 loop play>> <<timed 59s>> <<goto arrest>> <</timed>> <<countdownTimer 60 "arrest">>

<<print $brady3>> <p style="text-align:justify">You could give glycopyrrolate or atropine. But find atropine is already drawn up in the tray so you give that, flushing it well with the saline that Paul hands you. The BP finally settles on a number 78/- You cycle it again and watch the monitor for several long seconds. Henry comes crashing through the anaesthetic room doors into theatre with a look of worry etched across his face. He takes in the scene in a second then looks at you. "What's happening $firstname?" The pulse oximiter heart rate is finally climbing, 21...34...66...90...90..90 The BP settles again 119/88 You let out the breath you've been holding for the last minute. "She went really bradycardic, down to 20 something. I've given atropine." You gesture at the monitor by way of explanation. "It seems to have resolved."</p> [[Next|theatre6]] <<audio "monitorslow" pause>> <<audio "monitorfast" pause>> <<audio "monitorgofast" volume 0.5 play>>

<p style="text-align:justify">Henry turns to unseen others in the anaesthetic room and corridor outside who have come to help and with brief thanks explains everything is now in hand. “Shall I join you while Neil insufflates this time? Bit more slowly this time Neil?” Paul hands you a glass ampoule and a new 2 ml syringe. You turn it over in your hand to read the label. “Hang on one second. Just let me draw up another atropine.”</p> [[Next|theatre7]] <<audio "monitorgofast" pause>> <<audio "monitorfast" volume 0.5 loop play>> [[Tell me more about emergency drugs|drug1]]

<p style="text-align:justify">Ten minutes later and the surgery is well under way. Henry is typing something onto his phone. “Have you got this?” he asks offering it to you. You take it and look at the screen to see a bold grey/red/yellow cover of the [[Association of Anaesthetists Quick Reference Handbook on the screen|https://anaesthetists.org/Portals/0/PDFs/QRH/QRH_complete_June_2023.pdf?ver=2023-06-23-141011-603]].</p> <center> <img src="images/qrh.jpg" style="max-width: 400px;" alt="front cover of quick reference handbook"/> </center> <p style="text-align:justify">"I find it really useful, like they say in the guide 'using the same systematic approach: increases our chance of identifying the problem, reduces our risk of missing the problem; and limits us fixing attention inappropriately.' There’s usually a hard copy in a sensible place everywhere you will work ,and it’s worth knowing where because you can give it to a member of the team to read out loud and keep everyone on track during an emergency."</p> [[Next|theatre9]] <<audio "monitorfast" pause>>

<p style="text-align:justify">"Out of hours you need to think about where your help is coming from. You know what it’s like during the day, pull the emergency bell and you will be inundated with help. But when you are doing a case on the weekend, or in the evening, you need to be more canny when you have a problem. Obviously there’s the supervising consultant, but if they aren’t on site and need to come in..." He lets that hang for a moment. "But if you think about it there is always lots of help. You get the supervising consultant on their way but they can give you immediate advice over the phone. It’s also worth knowing who’s in for anaesthetics in obstetrics and in ICU when you’re on-call. Who’s the med reg? Support each other. Which of the consultants are resident? And the ODPs are great at keeping you on track while the cavalry arrives. And clearly prevention is better than cure so ideally just avoid the emergency all together."</p> [[Next|theatre9]]

<p style="text-align:justify">"Anyway. Knowing what an efficient surgeon Mr Timmins is..." Neil makes a non-committal grunt from the other side of the drape. Henry carries on talking to you "You had better talk me through how you are going to wake up this patient so I can leave you to it? Perhaps this time without the need for any emergency alarms?"</p> [[Next|theatre10]] <<set $when to "No answer given">>

<center> !!@@.typing;Emergency drugs^^1 *^^@@ </center> @@.typing;The RCoA recommends having these emergency drugs drawn up and ready to use: * Suxamethonium 100 mg in 2 ml * Atropine 1 mg in 1 ml * Ephedrine 30 mg in 10 ml of saline * Metaraminol 10 mg in 20 ml of saline @@ <div class="relaxant">''Suxamethonium''</div> @@.typing;For more drug info see scenario 2 ''Use'' Laryngospasm ''IV dose'' 25-50 mg@@ <div class="atropine">''Atropine''</div> <img src="images/atropine.jpg" style="float: left; max-width: 25%;" alt="atropine ampoule"/> @@.typing;''Presentation'' Clear colourless solution 0.5/0.6 mg.ml^^-1^^ ''Uses'' Treatment of bradycardia due to increased vagal tone, ALS – bradycardia algorithm, management of the effects of anticholinergic agents, organophosphate poisoning ''IV dose'' Perioperative bradycardia due to increased vagal tone 10 µg.kg^^-1^^ (adult 300-600 micrograms), critical bradycardia 20 µg.kg^^-1^^ (adult 0.5-1mg), ALS – bradycardia algorithm 500 micrograms repeated up to 3 mg <p style="text-align:justify">''Notes'' 3 mg will cause complete vagal block in adults. Low doses can cause initial bradycardia (Bezold-Jarisch reflex), bronchodilation, reduced bronchial and gastric secretions, central excitation or depression (<<link [[central anticholinergic syndrome->drug1]]>> <<set Dialog.setup("Central anticholinergic syndrome")>> <<set Dialog.wiki("Central anticholinergic syndrome is due to a decrease in the inhibitory acetylcholine action in the brain. Signs and symptoms include: somnolence, confusion, amnesia, hallucinations, dysarthria, ataxia, delirium.")>> <<set Dialog.open ()>> <</link>>), especially in the elderly, sweating inhibition which can cause a rise in temperature in children, urinary retention, pupilary dilation</p>@@ <div class="atropine">''Glycopyrrolate'' (Glycopyrronium bromide)</div> <img src="images/glyc.jpg" style="float: left; max-width: 25%;" alt="glycopyrrolate ampoule"/> @@.typing;''Presentation'' Clear colourless solution 0.2 mg.ml^^-1^^ or in 0.5 mg.ml^^-1^^ fixed dose combination with neostigmine 2.5 mg.ml^^-1^^ ''Uses'' Anticholinergic ''IV dose'' 5 µg.kg^^-1^^ (adult 200-400 µg) <p style="text-align:justify">''Notes'' Works within 3 minutes, vagolytic effects last 2-3 hours, antisialogogue effects last ~ 8 hours, bronchodilation, does not cross blood-brain barrier, no change in pupil size, reduces gastric secretions, reduces sweating but little effect on temperature </p>@@ <div class="upper">''Metaraminol''</div> <img src="images/metaraminol.jpg" style="float: left; max-width: 25%;" alt="metaraminol ampoule"/> @@.typing;''Presentation'' Clear colourless solution 10 mg.ml^^-1^^ - diluted in saline to a solution containing 0.5 mg.ml^^-1^^ or ready diluted 0.5 mg.ml^^-1^^ ''Uses'' Adjunct in the treatment of hypotension related to general or neuraxial anaesthesia ''IV dose'' 0.5 mg boluses titrated to effect <p style="text-align:justify">''Notes'' Synthetic sympathomimetic, predominant action at α adrenergic receptors (vasoconstricts), weakly active at β adrenergic receptor, indirect action via noradrenaline release. Onset 1-2 minutes, maximum effect at 10 minutes, lasts 20-60 minutes. ↑SVR, ↑pulmonary vascular resistance, causes a reflex bradycardia, <<link [[tachyphylaxis->drug1]]>> <<set Dialog.setup("Tachyphylaxis")>> <<set Dialog.wiki("Tolerance is the requirement of higher doses of a drug to produce a response. When this develops rapidly, after only a few administrations of the drug, this is called //tachyphylaxis//. Indirect acting sympathomimetics displace NA from storage vesicles, once these are depleted the same or increasing doses of the drug will not restore the physiological effect.")>> <<set Dialog.open ()>> <</link>> after repeated administration, nausea and vomiting, ↓renal blood flow, uterine contraction, extravasation causes tissue necrosis, risk of exaggerated response in patients with hyperthyroidism or on MAOI (see drug info in scenario 1)</p>@@ <div class="upper">''Ephedrine''</div> <img src="images/ephedrine.jpg" style="float: left; max-width: 25%;" alt="ephedrine ampoule"/> @@.typing;''Presentation'' Clear colourless solution 30 mg.ml^^-1^^ - diluted in saline to a solution containing 3 mg.ml^^-1^^ ''Uses'' Adjunct in the treatment of hypotension related to general or neuraxial anaesthesia ''IV dose'' 3-6 mg boluses titrated to effect <p style="text-align:justify">''Notes'' Naturally occurring sympathomimetic, action at α and β adrenergic receptors (↑SVR, inotropic, choronotropic), indirect action via noradrenaline release. Rapid onset, lasts up to 60 minutes. Risk of dysrhythmias (especially with halothane), tachyphylaxis with repeated administration, nausea and vomiting, ↓renal blood flow, ↓uterine tone. Exaggerated hypertensive response in patients on MAOI, doxapram, β-blockers, oxytocin</p>@@ <div class="upper">''Adrenaline''</div> <img src="images/adrenaline.jpg" style="float: left; max-width: 25%;" alt="adrenaline ampoule"/> @@.typing;''Presentation'' Clear colourless solution in either 0.1 mg.ml^^-1^^ (1:10,000 - the prefilled syringe in the cardiac arrest trolly) or 1 mg.ml^^-1^^ (1:1000 - glass ampoules or auto injector 'EpiPen') concentrations ''Uses'' ALS, anaphylaxis, low cardiac output states, local vasoconstrictor, adjunct in local anaesthetic solutions to prolong duration of action, nebulised to reduce airway inflammation or bronchoconstriction ''IV dose'' Cardiac arrest - 1 mg (10 ml 1:10,000) repeated as per ALS algorithm, suspected anaphylaxis 50-100 micrograms (0.5-1ml of 1:10,000) boluses titrated to effect. Can also be given via IV infusion, IM, SC, and via inhalation. <p style="text-align:justify">''Notes'' Sympathomimetic catecholamine, acting on α and β adrenergic receptors. As a bolus ↑SVR (α), inotropic, chronotropic. When given via infusion: low doses >β activity with ↓SVR/↓diastolic BP, high doses >α activity. Risk of tachycardia, myocardial ischaemia and dysrhythmias (especially with halothane, and to a lesser extent isoflurane/enflurane). Causes bronchodilation, ↓renal blood flow 40%, ↑BMR 20-30% which can cause pyrexia, CNS excitation, nausea and vomiting, inhibits contraction of the pregnant uterus</p>@@ <div class="notes">''Other emergency drugs''</div> @@.typing;''Intralipid 20%'' * For local anaesthetic toxicity * Fat emulsion * Inital dose 1.5 ml.kg^^-1^^ IV over 1 min * Also start IVI at 15 ml.kg^^-1^^.hr^^-1^^ * Monitor amylase or lipase for 48 h after use, risk of pancreatitis * See the Association of Anaesthetists QRH - [[Local anaesthetic toxicity|https://anaesthetists.org/Portals/0/PDFs/QRH/QRH_3-10_Local_anaesthetic_toxicity_v2_June%202023.pdf?ver=2023-06-23-141010-760]] ''Dantrolene'' * For malignant hyperthermia * Inhibits ryanodine receptors in skeletal muscle and ↓Ca^^+2^^ release * Each vial 20 mg as an orange powder reconstituted in 60 ml water for injection * The powder is difficult to dissolve and you need loads so get help for this * Initial dose 2.5 mg.kg^^-1^^ IV * Effects within 15 min, lasts 4-6 hours * Highly irritant if extravasated * See the Association of Anaesthetists QRH - [[Malignant hyperthermia crisis|https://anaesthetists.org/Portals/0/PDFs/QRH/QRH_3-8_Malignant_hyperthermia_crisis_v2.pdf?ver=2021-01-05-141951-520]] @@ [[Back|theatre6]] [[One page RCoA basic anaesthetic drugs summary sheet|https://rcoa.ac.uk/sites/default/files/documents/2019-11/ANAESTHETIC_DRUG_CRIB_SHEET-8.pdf]] @@.typing;''^^*^^ Doses are for an average adult. They are provided as a guide to the usual range of doses for fit ASA1/2 adult patients only. You should discuss these doses with your trainers and adjust the document as required according to local practice.''@@ <<audio "monitorfast" pause>> Ref: # Scarth E, Smith S. Drugs in anaesthesia and intensive care, 5th Edn. 2017, Oxford University Press # Advanced life support, 8th ed. 2021, Resusitation Council UK <A HREF="javascript:window.print()">Click to Print This Page</A>

"So when should you start thinking about any patient's emergence?" You think for a second. "Erm... [[During their preoperative assessment|theatre11][$when = "Correct"]] [[While planning their anaesthetic|theatre11][$when = "Not quite"]] [[During their induction|theatre11][$when = "Not quiet"]] [[About half way through the procedure|theatre11][$when = "Not quite"]] [[When the sutures are going in|theatre11][$when = "Not quite"]]

"<<print $when>>" <p style="text-align:justify">"People sometimes get fixated on all risks surrounding induction, while not associating emergence with ‘risk’. It’s akin to a pilot and the whole crew being really focused for take off and then ‘winging it’ for the landing." He pauses for a moment to appreciate his own play on words. "And in managing that ‘risk’ we need to be planning our strategy for emergence before we have even put the patient to sleep. Sometimes that strategy is going to be to avoid a general anaesthetic all together, sometimes it’s going to be deferring that emergence for our esteemed colleagues in ICU to work their magic and mitigate some of the risk. You only know that from talking to your patient, seeing them, and thinking right from the preassessment stage, how am I going to manage waking you up?" "I think it was NAP4 that identified a third of major airway complications occur during emergence and recovery^^[[1|ref1]]^^. Fortunately the difficult airway society have [[excellent algorithms|https://das.uk.com/content/das-extubation-guidelines]] for extubating, to get you thinking about airway risk factors and general risk factors so have a quick look at them."</p> [[Next|theatre12]] <<set $das to "No answer given">>

"So Miss Redbridge here is ASA II, her BMI 33 and she had a grade one view on laryngoscopy?" You nod. "Which of the DAS extubation guidelines would be relevant to her then?" [[Low risk algorithm|theatre13][$das = "Correct"]] [[High risk algorithm|theatre13][$das = "Not quite"]] <<set $nmb to "No answer given">>

"<<print $das>>, and we will come back to those guidelines in a minute." "Can you tell me what you absolutely must check in the countdown to emergence?" [[What their MAC is|theatre14][$nmb = "Not quite"]] [[When the last opioid was given|theatre14][$nmb = "Not quite"]] [[How much residual NMB do they have|theatre14][$nmb = "Correct"]] [[Whether the OPD is available to assist|theatre14][$nmb = "Not quite"]] <<set $rev to "No answer given">>

"<<print $nmb>>" <p style="text-align:justify">"For every patient you have given a NMB drug you ''must'' check the level of residual NMB before reducing the depth of anaesthesia. No exceptions. Not even the patient who ‘only’ had 20 mg atracurium half an hour ago. Use a peripheral nerve stimulator (PNS) to check the number of twitches they have on train-of-four (TOF) and write it down. The AAGBI recommend qualitative monitoring rather than ‘eyeballing’ twitches^^[[1|ref2]]^^. A TOF ratio of >0.9 tells you that their recovery from NMB is satisfactory for extubation^^[[2|ref2]]^^. If they are still paralysed keep them asleep obviously." You fish the PNS out of the anaesthetic machine draw, carefully place the electrodes, turn the dial to 40 mA, and press the button for TOF. There’s something. You try again with 50 mA. The left side of Lisa’s forehead crumples into a frown, one, two, three, times. "So is she ready for reversal with neostigmine?" </p> [[No|theatre15][$rev = "Not quite"]] [[Yes|theatre15][$rev = "Correct"]] <<set $neo to "No answer given">> <<set $nmbdas to false>> [[Tell me more about NMB monitoring|nmb-notes]]

"<<print $rev>>" "If she has three twitches then accepted practice is that we could give neostigmine to reverse the residual block she has^^[[1|ref4]]^^. Can you tell me how it does that?” You consider for a moment. "Neostigmine reverses residual block by... [[increasing acetylcholine release|theatre16][$neo = "Not quite"]] [[inhibiting acetylcholine breakdown|theatre16][$neo = "Correct"]] [[acting on acetylcholine receptors|theatre16][$neo = "Not quite"]] [[encapsulating non-depolarising NBM drugs|theatre16][$neo = "Not quite"]] <<set $vol to "No answer given">>

<center> !!@@.typing;NMB monitoring@@ <div class="notes">''Where?''</div> <img src="images/block.jpg" style="max-width: 100%;"/> </center> @@.typing;''Ulnar nerve (UN)'' * Best site to use if accessible * -ve (black) electrode - flexor crease ulnar border of forearm * +ve (red) 1-2 cm proximal parallel to FCU tendon * Response adductor pollicis; thumb adduction ''Temporal branch facial nerve'' * Risk of residual paralysis is 5 x greater than with UN, revert to UN at end of surgery if possible * -ve (black) electrode – just anterior to tragus of the ear * +ve (red) outer canthus of the eye * Response orbicularis oculi, frontalis and corrugator supercilii; eyebrow twitch ''Posterior tibial'' * -ve (black) electrode – 2 cm posterior to medial malleolus of the ankle * +ve (red) 2 cm above -ve electrode * Response flexor hallucis longus; planter flexion great toe @@ <center> <div class="notes">''How?''</div> </center> <p style="text-align:justify"> @@.typing;Make sure the skin is clean and dry. Stick adhesive electrode pads over the chosen nerve as in the picture above. Attach the PNS leads to the pads. Depress the button to deliver a ''supramaximal stimulus'' (selected mA stimulus that gives maximal twitch and no increase in twitch is seen with higher mA). Selecting TOF gives 0.2 ms at selected mA x 4 spaced 0.5 s apart (2 Hz). Note the response. Do not apply a supramaximal stimulus to an awake patient. It hurts. We have tested this to confirm.@@ </p> <center> <div class="notes">''Why?''</div> </center> <p style="text-align:justify">@@.typing;Non-depolarizing muscle relaxants cause a predictable response and recovery of twitch pattern, with a decrement in twitch height and number correlating with increasing receptor occupancy in a process known as //Fade//: * No twitches 100% receptors blocked or broken PNS * 1 twitch 90% blocked * 2 twitches 80% * 3 twitches 75% * 4 twitches 0-75% So even with four twitches, 75% of receptors can still be blocked! TOF ratio (magnitude of T4/T1) is useful for quantitative monitoring of NMB. A TOF ratio of 0.9 is accepted as an indication of adequate reversal. The Association of Anaesthetists recommend quantative monitoring. Onset of a single dose of depolarizing NMB (sux) causes a uniform reduction in twitch height and no fade, so this is less useful for monitoring (phase I block). With repeated doses, some of the characteristics of a non-depolarizing NMB occur and fade may be seen (phase II block).@@ </p> <center> <div class="notes">''Alternative stimulation patterns''</div> </center> <p style="text-align:justify">@@.typing;''Single twitch'' ''Tetanic stimulation:'' 5 s at 50 Hz – with residual NMB //fade// in muscle contraction is seen despite ongoing stimulus. Post-tetanic count (PTC) – is useful when profound residual NMB (i.e. TOF 0) is suspected or is desirable because of the nature of the surgery (e.g. some CNS, inner ear, or retinal surgery). A tetanic stimulus (as above) is applied followed 3 s later with repeated single stimuli at 1 Hz. The motor response to these single stimuli is called //post-tetanic fasciculation// with each twitch seen counted. The first twitch of TOF corresponds to a PTC of 9, so 90% receptor occupancy. ''Double-burst stimulation (DBS):'' detects even small levels of residual block. Two mini-tetanic bursts (2 or 3 impulses at 50 Hz in each burst) separated by 750 ms at supramaximal mA. If there is residual non-depolarizing NMB //fade// will be seen between the first and second contraction. The advantage is fade is easier to appreciate clinically in DBS than in TOF. @@ </p> !!!<p style="text-align:justify"> @@.typing;The bottom line: Given a NMB drug? Then check for residual block with a PNS on the ulnar nerve if you can access it. Facial or tibial nerve if not.@@ </p> <<if $nmbdas is true>>[[Back|theatre18b]] <<else>>[[Back|theatre14]] <</if>> [[Refs|ref3]] <A HREF="javascript:window.print()">Click to Print This Page</A>

# Klein A, Meek T, Allcock E, et al. Recommendations for standards of monitoring during anaesthesia and recovery. //Anaesthesia//. 2021 # McGrath C, Hunter J. Monitoring of neuromuscular block. //CEACCP//. 2006; 6(1):7-12 [[Back|theatre14]]

# Klein A, Meek T, Allcock E, et al. Recommendations for standards of monitoring during anaesthesia and recovery. //Anaesthesia//. 2021 # Cook T, Andrade D, Bogod J, et al. The 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: patient experiences, human factors, sedation, consent and medicolegal issues. //Anaesthesia//. 2014; 69 (10):1102-1116 # Pandit J, Andrade J, Bogod D, et al. The 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: summary of main findings and risk factors. //Anaesthesia//. 2014; 69:1089–101 # McGrath C, Hunter J. Monitoring of neuromuscular block. //CEACCP//. 2006; 6(1):7-12 # Viby-Mogensen J. Postoperative residual curarization and evidence-based anaesthesia. //BJA//. 2000; 84:301-3 [[Back|nmb-notes]]

# Thilen SR, Bhananker SM. Qualitative neuromuscular monitoring: how to optimise the use of a peripheral nerve stimulator to reduce the risk of residual neuromuscular blockade. //Cur Anesth Rep//. 2016; 6: 164–9 [[Back|theatre15]]

"<<print $neo>>" <p style="text-align:justify">"Neostigmine binds to the esteratic site of acetylcholinesterase and is much more slowly hydrolysed than ACh so sits in the enzyme longer. ACh accumulates in the neuromuscular junction and that allows competitive antagonism of the non-depolarizing NMB drug." Henry pauses and then carries on. "So we have established that she does have some residual NMB but we are at a point that could be reversed with neostigmine?" You nod. "Now, she is on sevoflurane for maintenance, and some opioids on board as well?" You glance over to the drugs tray to double check you’ve given the morphine and nod again. "So when are you going to turn the volatile off?"</p> [[Ten minutes from the end|theatre17][$vol = "Not quite"]] [[Five minutes from the end|theatre17][$vol = "Not quite"]] [[Two minutes from the end|theatre17][$vol = "Not quite"]] [[Hang on this is a trick question|theatre17][$vol = "Correct"]]

<<print $vol>> <p style="text-align:justify">"NAP5 reported that a fifth of accidental awareness cases occurred during emergence, and 85% of these unfortunate people experienced the distress of paralysis while awake^^[[1|ref5]]^^." "And that was a bit of a trick question, as it depends on what volatile you’re using, duration of the anaesthetic, the fresh gas flows (FGF), how fast your surgeon sutures and whether you are planning to extubate on the operating table or on the bed. On a PAT slide half way between the two is less than ideal." "So no hard and fast ‘rules’ I’m afraid, however, once you’ve reached steady state during an anaesthetic, if your FGF are low, any change to your vaporizer setting will only very slowly be reflected in the concentration in the circuit, and the MAC. Think about turning an oil tanker. If you want to get rid of the volatile you need to turn your flows right up, that’s your manoeuvrable speed boat."</p> <center> <img src="images/tanker.jpg" style="max-width: 80%;"/> </center> [[Next|theatre18a]]

# Pandit J, Andrade J, Bogod D, et al. The 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: summary of main findings and risk factors. //Anaesthesia//. 2014; 69:1089–1101 [[Back|theatre17]]

<div class="das">''Perform Awake Extubation^^[[1|ref6]]^^'' [[Preoxygentate with 100% oxygen|das1]] [[Suction as appropriate|das2]] [[Insert a bite block (e.g rolled up gauze)|das3]] [[Position the patient appropriately|das4]] [[Antagonise neuromuscular blockade|das5]] [[Establish regular breathing|das6]] [[Ensure adequate spontaneous ventilation|das7]] [[Minimise head and neck movements|das8]] [[Wait until awake (eye opening/obeying commands)|das9]] [[Apply positive pressure, deflate the cuff & remove tube|das10]] [[Provide 100% oxygen|das11]] [[Check airway patency and adequacy of breathing|das12]] [[Continue oxygen supplementation|das13]] </div> <<set $nmbdas to true>> [[Next|theatre19]]

<center> !!@@.typing;Suction as appropriate@@ <img src="images/suction.jpg" style="max-width: 100%;"/> </center> <p style="text-align:justify">@@.typing;Secretions/blood on the vocal cords can lead to ''coughing, breath holding and laryngospasm''. If it isn’t working the most likely problem is either the suction canister lid isn’t on tight, the tubing has detached, or the canister lining isn’t in. !!!DO: * ''Always have suction within reach'' during induction/emergence, that you have checked is working * Have suction ‘on’ and under the pillow during an RSI * Only suction what you can see when using a rigid (Yanker) sucker to avoid causing trauma to the soft tissues, use a laryngoscope to improve your view if needed * Consider using a soft suction catheter passed down the ETT or into the nasopharynx/oropharynx (but not up the nose in the presence of a basal skull fracture) * Withdraw slightly if the carina is felt before applying the suction as you withdraw the catheter when performing deep suction !!!DON'T: * Suction patients who are ‘light’ as this may trigger the gag reflex, coughing and biting on the sucker/ETT * Prod tonsillar beds after tonsillectomy/adenoidectomies BUT always check for clots in the nasopharynx, they are colloquially named ''//coroner's clots//'' for a reason (see NAP4) @@ [[Back|theatre18b]]<p style="text-align:right">[[Refs|ref8]]</p> <A HREF="javascript:window.print()">Click to Print This Page</A>

<center> !!@@.typing;Insert a bite block (e.g rolled up gauze)@@ <img src="images/bite.jpg" style="max-width: 100%;"/> </center> <p style="text-align:justify">@@.typing;A breath holding patient who has bitten into an ETT/LMA, which you then can’t remove, is really unfortunate (try telling them to stick out their tongue and some will release their bite to obey the instruction). Forced inspiratory efforts against a closed airway can also rapidly cause negative pressure pulmonary oedema which can be mitigated by letting down the cuff of the ETT/LMA so they can breath round the airway device and no significant negative pressure can be generated. Many supraglottic airway devices now have integral bite blocks. If not a judiciously placed roll of gauze (think fat cigar) between the molars and sticking out of the mouth avoids this scenario. A OP airway (Guedel) can also be used in some cases but is very rigid and may increase the risk of dental damage.@@ [[Back|theatre18b]]<p style="text-align:right">[[Refs|ref9]]</p> <A HREF="javascript:window.print()">Click to Print This Page</A>

<center> !!@@.typing;Position the patient appropriately@@ </center> <img src="images/position.jpg" style="float: left; max-width: 35%;"/> @@.typing;A ‘traditional’ left lateral head down position maintains airway patency, and reduces the risk of aspiration. In practice the vast majority of patients are extubated in a supine, sitting up position, which has the advantage of relative ease of reintubation in an emergency and confers a mechanical advantage for breathing in patients with >BMI. Think about the ergonomics of the space. If extubating on the bed/trolley make sure the patient's head is right at the top of the mattress, and the bed is low enough, use a step if necessary. Can you tilt it in a hurry if necessary? Are they safe from injury if they flail an arm or buck during emergence? Can you reach the anaesthetic machine especially your suction, APL valve and reservoir bag for ventilation?@@ [[Back|theatre18b]]<p style="text-align:right">[[Refs|ref10]]</p> <A HREF="javascript:window.print()">Click to Print This Page</A>

<center> !!Antagonise neuromuscular blockade </center> Clinical tests of recovery from NMB such as sustained head-lift do not rule out significant residual block. Quantitative, objective measurement of neuromuscular function should be used. For safe extubation the train-of-four (TOF) ratio should be greater than 0.9. We have covered NMB monitoring [[here|nmb-notes]]. <div class="notes">''Neostigmine''</div> ''Presentation'' Clear solution 2.5 mg.ml^^-1^^ or fixed dosed combination containing 0.5 mg glycopyrrolate and 2.5 mg neostigmine ml. ''Dose'' 0.05-0.07 mg.kg^^-1^^ given slowly ''Dose'' for 70kg person 3.5-4.9 mg given slowly <p style="text-align:justify">''Notes:'' Acetylcholinesterase inhibitor that antagonises non-depolarizing muscle relaxants (NDMR) by increasing available acetylcholine. Only for use when spontaneous recovery from NMB is evident and TOF count greater than 2. Peak effect at 7-10 minutes, duration around 1h, always monitor respiratory function during recovery, recurrence of block may occur. Glycopyrrolate or atropine is given with/before neostigmine to prevent bradycardia, excessive salivation and other muscarinic effects. Caution: in epilepsy, hyperthyroidism, hypotension, peptic ulceration, intestinal obstruction, and Parkinson’s disease; risk of bradycardia progressing rarely to asystole; can cause bronchospasm in asthmatics; may precipitate cholinergic crisis in patients with myasthenia gravis. Can potentiate suxamethonium and prolong phase 1 block.</p> <div class="notes">''Sugammadex''</div> ''Presentation'' Clear or pale yellow solution 100 mg.ml^^-1^^ ''Routine reversal once spontaneous recovery from NMB is evident and post-tetanic count 1-2'' 4 mg.kg^^-1^^ ''Routine reversal once spontaneous recovery from NMB is evident and T2 evident on TOF'' 2 mg.kg^^-1^^ ''Rescue reversal immediately post rocuronium administration'' 16 mg.kg^^-1^^ <p style="text-align:justify">''Notes:'' Modified gamma cyclodextrin (similar structure to Frebreeze) that encapsulates aminosteroid NDMRs vecuronium and rocuronium (limited data on pancuronium, not licenced for use) reducing drug availability at nicotinic receptors in the NMJ and rapidly reversing NMB. Caution: Monitor respiratory function during recovery, recurrence of block may occur. Rarely causes significant bradycardia. Hypersensitivity including anaphylaxis can occur. After a 4 mg/kg dose a minimum of 4h must elapse before using standard doses of aminosteroid NMBD, onset will be delayed and duration prolonged. In patients with mild to moderate renal impairment allow 24h before re-use of aminosteroid NDMR. Sugammadex not recommended in severe renal impairment including dialysis. Decreases available progesterone from hormonal contraceptives. After a 4 mg/kg dose of sugammadex for non-oral hormonal contraceptives (e.g. implants, vaginal rings, depot-provera injection) use a barrier contraceptive for 7 days and refer to package leaflet of their product. For oral contraceptives (e.g. combined or progesterone only pill) follow missed pill advice and consult the package leaflet of their product.</p> [[Back|theatre18b]]

<center> !!@@.typing;Establish regular breathing@@ <img src="images/breathing.jpg" style="max-width: 100%;"/> </center> <p style="text-align:justify">@@.typing;''//Respiratory drive//'' is the intensity of the output of the respiratory centres, which directly determines breathing effort when neuromuscular transmission, and respiratory muscle function, are intact. ''CO~~2~~ is the key player^^*^^...'' CO~~2~~ rapidly diffuses across the BBB altering the H^^+^^ of the CSF, this change is detected by ''central chemoreceptors'' on the ventral surface of the medulla. A tiny increase in PaCO~~2~~ above the set point is a powerful stimulus to breathing, with the converse also being true, low PaCO~~2~~ lowers respiratory drive. Opioids DECREASE the ventilatory response to CO~~2~~. Peripheral chemoreceptors in the carotid bodies are also sensitive to the PO~~2~~, PCO~~2~~, and pH of the arterial blood BUT a ventilatory response to hypoxia only occurs at a PaO~~2~~ of <10. Put this together: At the end of an anaesthetic, assuming residual neuromuscular blockade is reversed, as the concentration of volatile comes down, accumulating CO~~2~~ increases respiratory drive and the patient should resume regular breathing. Until regular breathing is established continue to support with either manual or mechanical ventilation to clear volatile from the lungs, but don’t over ventilate and lower the PaCO~~2~~ as the patient may remain apnoeic especially in the context of opioids.@@ </p> [[Back|theatre18b]]<p style="text-align:right">[[Refs|ref11]]</p> ^^*we are not talking about the small subset of COPD patients who depend on hypoxic drive for ventilation^^ <A HREF="javascript:window.print()">Click to Print This Page</A>

<center> !!@@.typing;Ensure adequate spontaneous ventilation@@ <img src="images/vent.jpg" style="max-width: 100%;"/> </center> <p style="text-align:justify">@@.typing;In the run up to extubation if the patient is on a supported mode of ventilation (PS or SIMV) with high levels of pressure support (PS) and/or positive end-expiratory pressure (PEEP) necessary to achieve adequate ventilation there is a risk hypoventilation, hypoxia and postoperative pulmonary complications if you suddenly remove that support on extubation. Prior to extubation aim to have a RR ≥8 and a TV of ≥6 ml.kg^^-1^^, on a PS of ≤8 cmH2O and/or a PEEP of ≤5 (support to overcome the resistance of breathing down an ETT).@@ </p> [[Back|theatre18b]]<p style="text-align:right">[[Refs|ref12]]</p> <A HREF="javascript:window.print()">Click to Print This Page</A>

<center> !!@@.typing;Minimise head and neck movements@@ </center> <img src="images/neck.jpg" style="float: left; max-width: 25%;"/> @@.typing;Stimulation during emergence runs the risk of triggering laryngospasm, breath holding, coughing and bucking. Especially in children, smokers, asthmatics, shared airway surgery and thyroid surgery.@@ [[Back|theatre18b]]

<center> !!@@.typing;Wait until awake (eye opening/obeying commands)@@ <img src="images/eyes.jpg" style="max-width: 100%;"/> </center> <p style="text-align:justify">@@.typing;During the emergence, patients should be extubated either in a deep plane of anaesthesia (by experienced colleagues who are familiar with the technique) or fully awake (what we are doing) but not in-between – that’s tiger country. When planning an awake tracheal extubation part of the consent process should include a discussion of the possibility of waking up with a tube in their throat, perhaps feeling temporarily weak and possibly having their breathing assisted as they recover from the effects of the anaesthetic. While the patient is in the lighter planes of anaesthesia it is important to keep talking to them, let them know the operation is over and they are just waking up, many reports of awareness occur during this phase and verbal reassurance may mitigate any adverse recall of events.@@ </p> [[Back|theatre18b]]<p style="text-align:right">[[Refs|ref13]]</p> <A HREF="javascript:window.print()">Click to Print This Page</A>

<center> !!!@@.typing;Apply positive pressure, deflate the cuff & remove tube@@ <img src="images/out.jpg" style="max-width: 100%;"/> </center> <p style="text-align:justify">@@.typing;Apply positive pressure = squeeze the reservoir bag with the APL closed on extubation. The positive pressure helps prevent secretions tracking up into the laryngeal inlet and potentially precipitating laryngospasm. You need really good communication with whoever is assisting with the extubation, this is the point where you transition from a controlled to an uncontrolled situation and you both need to know what’s going on. Don’t let time pressures influence this stage of the process, the patient is ready when they're ready.@@ </p> [[Back|theatre18b]]<p style="text-align:right">[[Refs|ref14]]</p> <A HREF="javascript:window.print()">Click to Print This Page</A>

<center> !!@@.typing;Provide 100% oxygen@@ <img src="images/o2.jpg" style="max-width: 100%;"/> </center> <p style="text-align:justify">@@.typing;While still in the recovery phase of anaesthesia it is prudent to keep the FRC filled with O~~2~~ to prolong the ‘safe apnoea time’ in an emergency and to provide a buffer for a degree of hypoventilation and atelectasis. Although its use is less prevalent nitrous oxide posses a risk of ‘diffusion hypoxia’. Nitrous rapidly coming out of the blood takes up all the space in the alveolus and reduces the partial pressure of O~~2~~ causing hypoxia, this is avoided with supplemental O~~2~~.@@ </p> [[Back|theatre18b]]<p style="text-align:right">[[Refs|ref15]]</p>

<center> !!@@.typing;Check airway patency and adequacy of breathing@@ </center> <p style="text-align:justify">@@.typing;Because you’ve conscientiously followed the previous steps, all being well, your patient will be maintaining their own airway and breathing perfectly. Sometimes a supporting head tilt chin lift or a //gentle// jaw thrust is necessary until the patient is more awake. ''However there are a number of recognised complications at extubation (incidence^^[[2|ref16]]^^):'' * Laryngospasm (25%) * Desaturation <94% (22%) * Coughing (18%) * Breath holding (13%) * Airway obstruction (5.5%) * Apnoea (2%) * Vomiting (2%) * Aspiration (0.5%) * Haemodynamic instability (2%) * Other things not on this list ''You are probably familiar with the signs of a partially or fully obstructed airway:'' * Agitation * Coughing * Snoring, gurgling, wheezing or stridor (abnormal high pitched sound on inspiration) * Intercostal and subcostal retractions * Substernal retractations (seesaw breathing) * Late signs: hypoxia/desaturation/cyanosis/cardiac arrest ''A partially obstructed airway generally responds to one or more of the following:'' * Oxygen * PEEP * Jaw support * Airway adjuncts * Propofol * Reversal drugs * Suxamethonium * Re-intubation For detailed management see the AAGBI Quick Reference Handbook, here’s [[the link|https://anaesthetists.org/Portals/0/PDFs/QRH/QRH_complete_January%202021.pdf?ver=2021-01-05-140039-337]] again if you need it. @@ </p> [[Back|theatre18b]]<p style="text-align:right">[[Refs|ref16]]</p> <A HREF="javascript:window.print()">Click to Print This Page</A>

<center> !!@@.typing;Continue oxygen supplementation@@ <img src="images/supplement.jpg" style="max-width: 100%;"/> </center> <p style="text-align:justify">@@.typing;The AAGBI recommends supplemental oxygen should be routinely given until full recovery, including while being transferred to the recovery area. After what has been covered here, you can see why.@@ </p> [[Back|theatre18b]]<p style="text-align:right">[[Refs|ref17]]</p>

Henry eyes you enquiringly. "Happy? Shall I'll leave you to it?" "Last time I said I was ‘happy’ I had to ring the emergency alarm, but yes I am ready to do this with you available if I need" you reply. "Excellent, I’m just in the office." [[Next|theatre20]]

"Anyway, I'm tired of the sound of my own voice." Neil snorts from where he's hauling a gallbladder out from the umbilical port site. Henry chuckles. "So why don't you have a look at the 'Awake Extubation checklist' on the low risk DAS algorithm? [[Show me|theatre18b]]

<p style="text-align:justify">Marion has pushed the emergency buzzer. The pulse oximeter isn't picking up any pulse now. Your fingers frantically feel for a carotid pulse. Nothing. The ECG trace is flat. You feel a moment of clarity. You have done this so many times before in simulation. “She is in asystolic cardiac arrest. Shirley can you start chest compressions, Marion, get the cardiac arrest trolley, Paul can you grab me a 1:10,000 adrenaline from out of the anaesthetic room. Naseer, can you watch the clock and keep us to time. Li take over from Shirley when she gets tired, Neil can you make sure the pneumoperitoneum is off.” Nods of comprehension all round. A room full of action. A thought comes to the forefront of your mind. Oxygen. You turn the FGF to 100% O~~2~~ and turn the volatile off. You give the atropine from the tray of emergency drugs and follow with a flush. Paul hands you a syringe of 1:10,000 adrenaline. You crack the box and give 1ml. “Naseer, that’s the 100 micrograms of adrenaline in. Can you tell me when two minutes is up?”</p> [[Next|arrest2]] <<audio "monitorslow" pause>> <<audio "emergency" volume 0.04 loop play>>

<p style="text-align:justify">Henry comes crashing through the anaesthetic room doors into theatre with a look of worry etched across his face. He takes in the scene in a second then looks at you. "What's happening $firstname?" "She's had an asystolic cardiac arrest. I've given atropine and I'm titrating 100 microgram boluses of adrenaline." "OK, has someone gone for the arrest trolley? Can someone shut off that irritating alarm so we can hear each other?" </p> [[Next|arrest3]] <<audio "emergency" volume 0.04 loop play>>

<p style="text-align:justify">Someone silences the alarm. "Yes, Marion's gone to get it." Just as you finish speaking a QRS complex zigzags onto the screen, followed by the another, then again. "Two minutes." Naseer announces to the room. "OK, rhythm check." You feel for a carotid pulse. There it is. "I can feel a pulse." You reach over to press the button on the anaesthetic machine to make the BP cycle. 78/- You let out the breath you've been holding for the last two minutes. </p> [[Next|arrest4]] <<audio "emergency" pause>> <<audio "postarrest" volume 0.4 play>>

Henry gives you a smile of relief. "OK, well done. What next?" "Post resuscitation care?" "Yes, that, and get some volatile back on. Watch her BP. I’ll give Brian a ring, he’s on for ICU. You get an ABG." Neil grimaces. "We need to make time to properly debrief. Frankly this list is //not// going well." [[Next|arrest5]] <<audio "postarrest" pause>> <<audio "monitor" volume 0.4 play>>

Sometime later and you find yourself sat in the staff room with your hands wrapped round a warm mug. Henry takes a seat beside you with his own obscenely strong looking coffee. "OK?" "Yep...it’s just...I was indecisive and I’d like another chance." [[You got it|theatre1]] <<audio "monitor" pause>>

<center> !!@@.typing;Preoxygentate with 100% oxygen How long have you got?@@ <img src="images/sand.jpg" style="max-width: 70%;"/> </center> * Oxygen consumption (VO~~2~~) anaesthetized patient ''250 ml.min^^-1^^'' * Replace the nitrogen in the <<link [[functional residual capacity (FRC)|das1]]>> <<set Dialog.setup("Functional residual capacity")>> <<set Dialog.wiki("FRC = volume of gas in the lung at the end of expiration during tidal breathing = expiratory reserve volume + residual volume. LOWER WHEN SUPINE but IMPROVED WITH PEEP")>> <<set Dialog.open ()>> <</link>>with oxygen extends the ‘safe apnoea time’ <<link [[‘safe apnoea time’|das1]]>> <<set Dialog.setup("Safe apnoea time")>> <<set Dialog.wiki("safe apnoea time = time until SaO2 ≤88% ")>> <<set Dialog.open ()>> <</link>> * On an awake patient use a tight fitting mask, with O~~2~~ at 15 L.min^^-1^^ * ''8 vital capacity breaths in one minute'' gives almost double the safe apnoea time vs the alternative of three minutes tidal ventilation * Optimal End tidal (E~~t~~) O~~2~~ ≥90% (watch your screen) * SpO~~2~~ of 100% on a pulse oximeter does not indicate optimal preoxygenation * If there is a risk of rapid desaturation (see the list below) then passive oxygenation with nasal cannula (already in place turned right up) during apnoea time can improve oxygenation if their airway is open <div class="notes">''Let's do the maths''</div> * Lisa is 157cm tall * IBW ~ 55kg * FRC ''30-35 ml.kg^^-1^^'' * Lisa's FRC ≈ 55 kg x 30 ml.kg^^-1^^ ~ ''1,650 ml'' * Room air inspired fraction O~~2~~ (F~~i~~O~~2~~) 0.21 * This mixes with expired gases/water vapour so fraction O~~2~~ in alveoli (F~~A~~O~~2~~) in the region of 0.13 * F~~i~~O~~2~~ during the maintenance phase of the anaesthetic whatever you set, generally around 0.4, also mixes with expired gases/water vapour, so the fraction O~~2~~ in alveoli slightly less ''On room air'' Fi O~~2~~ of 0.21 ≈ F~~A~~O~~2~~ in the region of 0.13: 1,650ml x 0.13 ≈ 200 ml O~~2~~ less than ''1 minute safe apnoea time'' ''On Fi O~~2~~ of 0.4'' ≈ F~~A~~O~~2~~ in the region of 0.32: 1,650 x 0.32 ≈ 500 ml about ''2 minutes'' ''With preoxygenation on Fi O~~2~~ of 1.0'' for 3 minutes ≈ F~~A~~O~~2~~ in the region of 0.92: 1,650 x 0.92 ≈ 1500 ml about ''6 minutes'' <div class="notes">''Patients with ↓ safe apnoea time:''</div> * Critical illness * Obesity * Pregnancy * ↑ Metabolic rate (infants, hyperthyroid, febrile) * Physiological shunt and dead space * Airway occlusion (↓FRC due to resorption atelectasis, blood diverted away from collapsed lung units – shunt) [[Back|theatre18b]]<p style="text-align:right">[[Refs|ref7]]</p> <A HREF="javascript:window.print()">Click to Print This Page</A>

<p style="text-align:justify">We are absolutely thrilled that you have found us and shown an interest in our learning platform. We wanted to give you the heads up before you get any deeper into the scenario, that like the best medical dramas, bad things may happen. This is to support learning and clinical decision making. It is ''REALLY RARE'' for things like this to happen to otherwise well people undergoing anaesthetics. The Royal Collage of Anaesthetists has some really helpful information explaining the risks of having an anaesthetic if you want further information, available [[here|https://rcoa.ac.uk/patient-information/patient-information-resources/anaesthesia-risk]]. When you are ready, welcome to our virtual world...</p> [[Start|Introduction]]

Reproduced from Popat M, Mitchell V, Dravid R, Patel A, Swampillai C, Higgs A. Difﬁcult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia// 2012; 67:318–340, with permission from the Association of Anaesthetists of Great Britain & Ireland/Blackwell Publishing Ltd [[Back|theatre18b]]

Paul looks at you appraisingly. "Enough emergencies for one day?" You try to look both confident and reassuring "Absolutely. [[Let's get this tube out|video]]." [[transcript]]

# Popat M, Mitchell V, Dravid R, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia//. 2012; 67:318-340 # Sirian R, Wills J. Physiology of apnoea and the benefits of preoxygenation. //CEACCP//. 2009; 9(4):105-108 # Karmarker S, Varshney S. Tracheal extubation. //CEACCP//. 2008; 8(6):214-220 # Rajan S, Mohan P, Paul J, Cherian A. Comparison of margin of safety following two different techniques of preoxygenation. //J Anaesthesiol Clin Pharmacol//. 2015; 31:165–8 [[Back|das1]]

# Popat M, Mitchell V, Dravid R, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia//. 2012; 67:318-340 [[Back|das2]]

# Popat M, Mitchell V, Dravid R, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia//. 2012; 67:318-340 [[Back|das3]]

# Popat M, Mitchell V, Dravid R, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia//. 2012; 67:318-340 [[Back|das4]]

# Jonkman A, Vries H, Heunks L. Physiology of the Respiratory Drive in ICU Patients: Implications for Diagnosis and Treatment. //Crit Care//. 2020; 24:104 # Del Negro CA, Funk GD, Feldman JL. Breathing matters. Nat Rev Neurosci. 2018;19:351–67 # Telias I, Brochard L, Goligher EC. Is my patient’s respiratory drive (too) high? Intensive Care Med. 2018;44:1936–9 # Popat M, Mitchell V, Dravid R, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia//. 2012; 67:318-340 # Coates EL, Li A, Nattie EE. Widespread sites of brain stem ventilatory chemoreceptors. J Appl Physiol (1985). 1993;75:5–14 [[Back|das6]]

# Ball L, Pelosi P. Intraoperative ventilation and postoperative respiratory assistance. //BJA Ed//. 2017; 17(11):357-362 # Popat M, Mitchell V, Dravid R, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia//. 2012; 67:318-340 [[Back|das7]]

# Kim M, Fricchione G, Akeju O. Accidental awareness under general anaesthesia: incidence, risk factors, and psychological management. //BJA Ed//. 2021; 21(4):154-161 # Pandit J, Andrade J, Bogod D, et al. 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia: summary of main findings and risk factors. //BJA//. 2014; 113 (9):549 # Gavel G, Walker R. Laryngospasm in anaesthesia. //CEACCP//. 2014; 14(2):47-51 # Popat M, Mitchell V, Dravid R, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia//. 2012; 67:318-340 [[Back|das9]]

Popat M, Mitchell V, Dravid R, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia//. 2012; 67:318-34 [[Back|das10]]

# Popat M, Mitchell V, Dravid R, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia//. 2012; 67:318-340 [[Back|das11]]

# Popat M, Mitchell V, Dravid R, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia//. 2012; 67:318-340 # Rassam S, SandbyThomas M, Vaughan J. Airway management before, during, and after extubation: a survey of practice in the United Kingdom and Ireland. //Anaesthesia//. 2005; 60(10):995-1001 [[Back|das12]]

# Association of Anaesthetists of Great Britain and Ireland. Recommendations for standards of monitoring during anaesthesia and recovery. //Anaesthesia//. 2016; 71: 85-93 # Popat M, Mitchell V, Dravid R, et al. Difficult Airway Society Guidelines for the management of tracheal extubation. //Anaesthesia//. 2012; 67:318-340 [[Back|das13]]

!!!@@.greentext;EPA 1: Performing an Anaesthetic Preoperative Assessment@@ EPA for this scenario in ''bold'' * Take a focused history, perform appropriate physical examination and interpret relevant investigations * Understand how a patient’s past medical, surgical and anaesthetic history influences the safe conduct of anaesthesia * Identify patients with an increased ‘perioperative risk’ and raise concerns appropriately * Communicate the anaesthetic plan to patients in an understandable way, including counselling on commonly occurring risks and addressing patient concerns * ''Understand limitations and scope of practice of a novice anaesthetist'' !!!@@.greentext;EPA 2: General anaesthesia for an ASA I/II patient having uncomplicated surgery@@ * ''Understand your scope of practice as an inexperienced practitioner and seek help appropriately'' * Plan and deliver general anaesthesia to appropriate patients including the following techniques: airway management with supraglottic devices and endotracheal intubation; spontaneous and controlled ventilation; rapid sequence induction * ''Prepare and check emergency drugs and equipment commonly used in anaesthetic practice'' * Independently check and use a standard anaesthetic machine * ''Manage tracheal extubation, including common complications occurring during emergence from anaesthesia; e.g. laryngeal spasm'' * Manage acute postoperative pain including the use of rescue opioids in recovery and patient controlled analgesia * ''Demonstrate understanding and capability in Anaesthetic Non-technical Skills'' * ''Initiate management of common anaesthetic emergencies, including unanticipated difficult airway management, and call for senior help'' [[Back|Core clinical learning objectives]]

!!@@.greentext; 2021 Curriculum learning syllabus stage 1@@ !!!@@.greentext;Perioperative medicine and health promotion learning outcomes:@@ @@.greentext;''//Identifies clinical and social challenges that increase risk for patients undergoing surgery Appreciates the principles of sustainability in clinical practice//''@@ !!!@@.greentext; ''Key capabilities''@@ * Explains the patient, anaesthetic and surgical factors influencing patient outcomes * Applies a structured approach to preoperative anaesthetic assessment of ASA 1-3 patients prior to surgery and recognises when further assessment and optimisation is required * Explains the effect that co-existing disease, subsequent treatment and surgical procedure may have on the conduct of anaesthesia and plans perioperative management accordingly * Explains individualised options and risks of anaesthesia and pain management to patients * Considers patient informed preference when obtaining consent for anaesthetic procedures !!!@@.greentext;General anaesthesia learning outcome:@@ @@.greentext;''//Provides safe and effective general anaesthesia with distant supervision for patients undergoing non-complex elective and emergency surgery within a general hospital setting//''@@ !!!@@.greentext;Key capabilities@@ * Conducts comprehensive pre-anaesthetic and preoperative checks * Safely manages induction and maintenance of anaesthesia by inhalational and intravenous techniques, extubation and emergence from anaesthesia * Plans recovery care, and manages recovery from anaesthesia utilising safe discharge criteria * Diagnoses and manages common perioperative complications These scenarios are ''not'' designed for exam revision. They are to support your leaning during the IAC and ultimately help you make good decisions at 2am. [[Back|Core clinical learning objectives]]

<center> !!!BETA Test Virtual Anaesthetics_3 <<link [[What is Beta Testing?|beta]]>> <<set Dialog.setup("What is Beta Testing?")>> <<set Dialog.wiki("@@.greentext;Beta testing is an opportunity for real users to use a product in a production environment to uncover any bugs or issues before a general release. Beta testing is the final round of testing before releasing a product to a wide audience. The objective is to uncover as many bugs or usability issues as possible in this controlled setting.@@")>> <<set Dialog.open ()>> <</link>> !!![[Start scenario|Intro 1]] </center>

<img src="images/wing.png" style="max-width: 30px" alt="small wing"/>@@.name; Virtual Anaesthetics_3@@

''>'' On each page there are clickable links within the text. ''>'' Navigate using the links in the scenario or the forward and back arrows in the left menu bar NOT the forward and back arrows on your internet browser. ''>'' Each scenario should take around an hour. ''>'' Your time spent accessing the scenario is recorded on your completion certificate. ''>'' If you access the scenario several times the certificate will only show the duration of the most recent access. ''>'' For the best platform experience access from a larger screen device such as a tablet ''>'' ''Check you're not on mute''. ''>'' When printing your certificate from a mobile device turn to portrait orientation. [[Back|Intro 1]]

<<set _answer to "">> !!!@@.greentext; Welcome to the trainers area of this scenario@@ Please input the password to continue: <<textbox "_answer" "">> <<button "Check Password">> <<if _answer is "">> <<script>>UI.alert("You did not supply a password");<</script>> <<else>> <<set _answer to _answer.trim().toLowerCase()>> <<if _answer is "vatrainersarea">> <<goto "trainers_area2">> <<else>> <<script>>UI.alert("Incorrect password");<</script>> <<goto "trainers_area">> <</if>> <</if>> <</button>>

Trainer guide for this scenario available ''[[here|https://www.virtualanaesthetics.com/trainerguides/IACmodule3.pdf]]'' [[Back|Introduction]]

/* Update the time of the previous history record if there is one. */ <<if $history.length gt 0>> <<set $history.last().time to Date.now()>> <<else>> /* Record the time the first passage was shown. */ <<set $started to Date.now()>> <</if>> /* Add current passage's history record to the array, unless it has a 'no-history' passage tag. */ <<if not tags().includes('no-history')>> <<set $history.push({ "passage": passage(), "time": 0 })>> <</if>>