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Deep extubations
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Definition: Deep extubation is the process of removing the airway tube (LMA or endotracheal tube) before the patient is awake. The patient may be fully or partially anesthesitized. The point is that they do not have protective airway reflexes in place.
Rational: Con; many anesthesia providers consider the technique dangerous. The lack of airway reflexes leaves the patient vulnerable to aspiration. If the patient is light or when they become light laryngospasm may occur leading to serious hypoxia or pulmonary edema. Pro; Deep extubation provides more reliable anesthesia end of case time of < 5 minutes (patient out of room - dressing applied time). It makes the lack of coughing unlikely unless you have a heavy narcotic technique in which case you will have a high PONV rate. It maintains the anesthesia providers' airway management skills. These skills become necessary in other scenarios. As stated in laryngospasm many providers cannot properly manage airway emergencies. This seems to be limited to those who never do an adult mask induction, always intubate immediately after induction and extubate only awake patients. Therefore they lack airway skills and create a self fulfilling prophecy. How dangerous is intubation for a provider that was not trained in the airway algorithm has no experience in intubation other than laryngoscopy and never has done more than 5 laryngospocies a year? Yet that is the case with extubation. All difficult airway courses, text books and discussions about airway management rarely deal with anything other than intubation. Residents and SRNA's often go for their full training without doing a deep extubation. Yet many deaths and major lawsuits result from the extubation process. Courts have recognized written opinions that the emergence process is "more risky than at any other time in the anesthesia process" I personally know of 5-10 cases of death or serious hypoxic permanent injuries in the last 15 years yet I have heard of no intubation injuries as I used to in the 70's and 80's. There are measurable hypoxic events (SPO2 < 85 for > 120 seconds) on emergence and early PACU> these events almost never occur on inductions anymore. In other words airway training for emergence is poor and this results in complications. When providers with poor skills get caught in other accidental extubations, a misjudged early extubation, laryngospasm events, airway foreign bodies; they loose the airway and create the complications they are worried about. But since all cases of laryngospasm are a failure of the provider to manage the airway the issue is the provider not the technique of deep extubations. Skilled providers can go for a career without any hypoxic events of these complications. Aspiration of clear normal PH fluid is of no consequence. So as long as the stomach is empty of food and the PH and volume is OK then deep extubation is safe, even with a history of GERD. Technique: First, decide if you are going to do a deep extubation. I exclude full stomachs, head tongs, difficult airway as determined by induction and TMJ cases. This leaves > 90% of cases as appropriate for deep extubation. I do not exclude OSA and GERD patents as automatic exclusions. These are some of the patients who do the most poorly with a coughing bucking hypertensive emergence. But don't start with these cases. TMJ may be aggravated by a prolonged jaw thrust. Next, run your case to make the deep extubation process easier. 25% of my cases are narcotic free (resulting in a measured PONV rate of < 3% with pain scores <4 in those cases). I run the rest of my cases with low dose narcotic (1-3 ML of fentanyl for a 1 hour lap choly), 1-1.3 MAC plus several other analgesia techniques. Many breathe spontaneously for the full case and when on a ventilator I run the ET CO2 around 50 torr. Always keep one twitch on the nerve stimulator. All this makes it easy to get respirations going early in the emergence process. One many cases this can happen before closure. On others one should wait until after the fascia is closed. Watch the ET agent closely and do not let that drop because you are under ventilating. With Desflurane you can lighten the patient as under ventilation resulting in emergence before the case is done. Once spontaneous ventilation occurs, then titrate narcotics (0.5 ml fentanyl) to a respiration rate of 15-18. This will assure a comfortable emergence. This titration may have to continue into PACU and may well be the most difficult part to learn. If the initial rate is <13 then you gave too much narcotic and your airway management will be twice as long since the decreased ventilation leads to a slower elimination of the agent. This is why I almost always use Desflurane as the airway support time of Desflurane for 1.3 MAC is about 3 minutes compared to 8 minutes for other agents. This results in less chance of fatigue and loss of airway control on the provider’s part. Also, three minutes of a very low vigilance decrement is easier to maintain than 8 minutes. AIRWAY VIGILANCE IS CRITICAL AND NO DISTRACTIONS ARE ALLOWED, NOT EVEN FOR ONE BREATH. The rate of coughing is no higher at equal MAC levels with Desflurane compared to any other agent after induction. All Agents except Sevoflurane and ether are pungent and produce coughing on induction (including trans-tracheal lidocaine). Yet there is no coughing from any agent including halothane, Desflurane and lidocaine while they are wearing off unless a tube is in place. With a tube they cough at equal "MAC" brain levels. The narcotic titration should never result in hypoxia if the airway is always open and the patient is in an O2 enriched environment. Throughout the entire process, the FIO2 should be >50% but < 75% to avoid absorption atelectasis. Never use > 75% for > 5 minutes even for extubation especially in the obese because atelectasis will occur very rapidly. Do not have the O2 on 100% for ten minutes trying to get them to breathe. The third step is relaxant reversal. If done, it need not necessarily be done to get the diaphragm working enough to count the rate. Normal minute ventilation can be achieved with > 50% blockade. This does not in any way mean that the patient is ready for extubation. With a very long closure you may be in this stage for an hour. Just cruise at 0.7-1.3 MAC and titrate Narcotic to keep respiration between 15 and 18. This MAC range depends on the type of case, smoking history, and presence of other analgesics like blocks, chronic narcotics, ketamine, NSAIDS, Tylenol, neurontin type drugs, and beta blockers. Significant recovery should of course be obtained either spontaneously or with reversal before extubation and full recovery demonstrated before the end of anesthesia time. Now you just wait until the skin is nearly closed and your chart is caught up. Then you can extubate and convert to a mask anesthetic. Do not turn off the agent. Establish the airway with a jaw thrust. Do not place an oral airway if it might cause bleeding as in a tonsillectomy or dentition is an issue. A good jaw thrust is all you need. The mouth is open with a good jaw thrust. Turn off the agent a minute or two before the dressing is done. Continue to titrate narcotic if needed. Be very vigilant and never let go of the airway until the patient moves spontaneously. The risk of laryngospasm is low but the risk of hypoxic laryngospasm is 0 in skilled hands if the jaw thrust is in place. Even if the patient is light and reacting to the tube you can extubate. Light extubation has a greater chance of laryngospasm only if you do not do a jaw thrust. Extubation is the major mistake many providers do. They set themselves up for laryngospasm. First suction, next extubate with the cuff partially inflated to swab the 10ml of secretions that can be above the cuff and below the cords. If this falls to the carina the patent may cough. Then hand the circuit and tube to your assistant and do a jaw thrust with the mask within 5 seconds. Remember a stretched skeletal muscle cannot contract so a good jaw thrust will always prevent laryngospasm. Do not take 30 seconds to disconnect the tube from the circuit, connect the mask, lay the mask on the face and observe the respiration. By this time the laryngospasm may be set in too hard to break easily. Open the airway and observe the respiration first and let your assistant connect the circuit to the mask. If the patient cannot tolerate 20-3 breaths of room air, then you should not have extubated. Observe for respiration and apply CPAP if needed to increase tidal volume. Once respiration is adequate then remove the circuit for an open O2 source so that rebreathing is eliminated. You may now go to PACU but you must maintain airway support until the patient moves spontaneously. With Desflurane the patient will be moving before you are done with report if the respirations are 15-18/minute. Of course this gets adapted a little to a fast surgical closure but the process is still the same one step at a time. Don't give narcotics in anticipation of the need. Also, don't extubate expecting respirations to be OK. Late case vs. front loading narcotics do not result in increased narcotic need as long as the initial pain scores are low. With this technique, you will be out of the O.R. consistently within 5 minutes of the surgeon being done. You will extubate before or within a minute of when he is done even when his closure is 5 minutes long.