Ventilation is the most important skill in airway management, and most of us learned to do it incorrectly. Slideset. As given at Emcrit’s critical care conference.
In addition to improving laryngeal view, there is now evidence that elevating the head of the bed prolongs apneic desaturation time. This makes good sense, and the tradition of intubating patients in the supine position should be added to the long list of Things We’ve Been Doing Wrong All This Time. Using semi-fowlers position also probably reduces the risk of regurgitation/aspiration, and is strongly recommended for all patients being intubated for upper GI bleed. But make it your routine and you will benefit when that extra little bit of glottic view, those extra few seconds of apnea, and that extra bit of protection against regurgitation really matter. There is no downside. Purpose Failed airway is the anesthesiologist’s nightmare. Although conventional preoxygenation can provide time, atelectasis occurs in the dependent areas of the lungs immediately after anesthetic induction. Therefore, alternatives such as positive end-expiratory pressure (PEEP) and head-up tilt during preoxygenation have been explored. We compared the conventional preoxygenation technique (group C) with 20° head-up tilt (group H) and 5 cmH2O PEEP (group P) in non-obese individuals for non-hypoxic apnea duration. Methods A total of 45 patients were enrolled (15 in each group). After 5 min of preoxygenation, intubation was performed after induction of anesthesia with thiopentone and succinylcholine. After confirming the tracheal intubation by esophageal detector device and capnogram, all patients were administered vecuronium to maintain neuromuscular blockade and midazolam to prevent awareness. Post-induction, patients in all groups were left apneic in supine position with the tracheal tube exposed to atmosphere till the…
A middle aged gentleman presents with a basin filled with bright red blood. He’s choking, gagging and every ten seconds coughing up another huge mouthful. His daughter tells you that he has a base of tongue tumor that, 20 minutes ago, started bleeding. A lot. Asphyxiation and exsanguination are both immediate concerns. He clearly needs to be intubated now. But how? Awake technique is very unlikely to be successful; the patient is in extremis, blood pouring out of his mouth. He will need RSI. But you have at least two reasons to be concerned about RSI: 1. The huge amount of blood filling the oropharynx will obsure your view of the glottis. 2. The base of tongue tumor. Lord knows what you’ll see when you get in there. The answer: Four Provider ED Double Setup. Provider #1: Performs video laryngoscopy. Provider #2: To the right of provider #1, performing suction. Provider #3: To the left of provider #1, peforming suction. Provider #4: At the patient’s side, prepared to perform cricothyrotomy. For patients with massively bleeding oral lesions, bilateral suction, simultaneous with airway visualization, is necessary. Until recently, this was almost impossible, because only the operator can see the glottis during conventional laryngoscopy. Video laryngoscopy, however, has changed the rules. In addition to getting your eyes much closer to your target, with video laryngoscopy more than one person can participate in laryngoscopy at the same time. The magnitude of this advantage wasn’t apparent to me until a middle aged gentleman with basin filled with…
by reuben in _lecture, airway, kids
slideset available here.
This post has been superseded by this one EDICTv12 [acrobat format] Changes from version 11: * Torso angle of 30 degrees recommended * Nasal cannula for preoxygenation and apneic oxygenation recommended * LMA moved from difficult to basic airway equipment * Magill forceps moved from basic to difficult airway equipment * Rocuronium dose changed from 1-1.2 to 1.2 mg/kg * Reduced tidal volume wording clarified “if sepsis / prone to lung injury” * DVT prophylaxis removed from post-intubation maneuvers * “Verify that airway equipment is ready for next patient” added to post-intubation maneuvers * “Consider effects of decreased preload as PEEP is augmented” warning added to PEEP chart
Aligning the external auditory meatus to the sternal notch goes a long way toward optimizing head position relative to the chest, however, this is only the best estimate. You cannot know the head position that will maximize glottic view until you get in there. The best approach is as follows: Before even attempting insertion of the laryngoscope, put the patient’s entire occiput in the palm of your right hand. An assistant should be pulling the right corner of the mouth. Then use your right hand to gently elevate the head toward the ceiling (augmenting sniffing position) and extend the neck. If the patient is adequately relaxed, this maneuver will open the mouth and open the angle between the neck and sternum (see pics below), facilitating easy insertion of the laryngoscope. Insert the laryngoscope blade and control the tongue. As you gently advance toward the epiglottis, continue to maneuver the head by (a) moving it toward or away from the ceiling and (b) extending or flexing the neck, as dictated by whatever maneuvers maximize your view of the glottis. Once the patient’s head is in the position that maximizes glottic view, you need to mobilize your right hand to either take the endotracheal tube/bougie or, if the glottic view is still inadequate, externally optimize the larynx with bimanual laryngoscopy. Most operators can easily use the laryngoscope to suspend the head of most patients in the optimal position while they use their right hand for other tasks. If the patient’s head is too heavy to comfortably hold up, an assistant…
by reuben in _lecture, airway
high-def vimo screencast here. slideset here. audio here.
BVM should be replaced with LMA ventilation. Aside from that, if this technique is half as effective as they suggest, we need to know about it because we bag a lot of edentulous patients. Background: In edentulous patients, it may be difficult to perform face mask ventilation because of inadequate seal with air leaks. Our aim was to ascertain whether the "lower lip" face mask placement, as a new face mask ventilation method, is more effective at reducing air leaks than the standard face mask placement. Methods: Forty-nine edentulous patients with inadequate seal and air leak during two-hand positive-pressure ventilation using the ventilator circle system were prospectively evaluated. In the presence of air leaks, defined as a difference of at least 33% between inspired and expired tidal volumes, the mask was placed in a lower lip position by repositioning the caudal end of the mask above the lower lip while maintaining the head in extension. The results are expressed as mean ± SD or median (25th-75th percentiles). Results: Patient characteristics included age (71 ± 11 yr) and body mass index (24 ± 4 kg/m2). By using the standard method, the median inspired and expired tidal volumes were 450 ml (400 -500 ml) and 0 ml (0 -50 ml), respectively, and the median air leak was 400 ml (365-485 ml). After placing the mask in the lower lip position, the median expired tidal volume increased to 400 ml (380 – 490), and the median air leak decreased to 10 ml (0-20 ml) (P ± 0.001 vs….
see the updated version: http://emupdates.com/2012/07/08/emergency-department-intubation-checklist-v13/
by reuben in .trauma-general, .trauma-head & face, airway
In this month’s Canadian Journal of Emergency Medicine, Filanovsky et al describe how studies in the 70s associate rises in ICP to ketamine, and review more recent, higher quality evidence to the contrary. They do not mention that several of the early studies examined the influence of ketamine on ICP in non-intubated patients. Ketamine is well-known to cause brief periods of apnea, especially if pushed quickly; these short episodes are clinically inconsequential when ketamine is used for PSA and irrelevant when ketamine is used for RSI, where patients are simultaneously paralyzed. However, transient rises in pCO2 will cause cerebral vasodilation and a rise in ICP. Apnea time should therefore be minimized in patients potentially susceptible to ICP fluctuations, but this strategy applies to all induction agents used for RSI. Filanovsky et al also review evidence suggesting that ketamine may in fact be neuro-protective in head trauma, though the jury is still out on this question. They also note the concerns around the adrenal effects of etomidate, the induction agent most often used in polytrauma. While we know that etomidate infusions increase ICU mortality, it’s so far unclear if single-dose etomidate used for RSI causes clinically consequential adrenal suppression. Irrespective of these two issues, given the tendency of ketamine to increase blood pressure, it should be the induction agent of choice in the hypotensive trauma patient, with or without head injury. CJEM 2010;12(2):154-157