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You’re an anesthesiologist. You’ve lost the airway on your obese anesthetized gynecology patient, your multiple attempts to intubate the trachea have failed, you cannot mask ventilate the patient, and insertion of a laryngeal mask airway did not help. Your patient’s skin and lips are purple and you are terrified. What do you do?
- Call a surgeon stat to do a tracheostomy
- Ask the gynecologist to cut an airway into the patient’s neck
- Keep trying to intubate the trachea yourself
- Insert a needle into the cricothyroid membrane, and begin jet ventilation
- Cut an airway into the neck yourself.
A study in the October 2019 issue of Anesthesiology showed that when a “can’t intubate, can’t oxygenate” crisis occurred, there were delays finding someone prepared to cut a surgical airway into the front of the neck in time to save the patient’s life. The study looked at malpractice closed claims and found: 1) Outcomes remained poor in malpractice closed claims related to difficult tracheal intubation; 2) The incidence of brain damage or death at induction of anesthesia was 5.5 times greater in the years 2000 – 2012 than in the years 1993 – 1999; 3) Inadequate planning and judgement errors contributed to the bad outcomes; and 4) Delays in placing a surgical airway during “can’t intubate, can’t oxygenate” emergencies were a major issue.
A closed claims study is akin to a large mortality and morbidity (M & M) conference. A closed claims study tells us which complications led to malpractice settlements. Each malpractice closed claim marks a negligent practice which caused an adverse outcome.
I’d like to focus on one specific aspect of this important study: anesthesiologists need to lose their reluctance to cut a surgical airway into a patient’s neck in a “can’t intubate, can’t oxygenate” airway emergency. A surgical airway is an invasive airway via the front of the patient’s neck into their trachea. Waiting for a surgeon to cut a surgical airway, or fearing to cut a surgical airway yourself, could cost your patient his or her life. Delay or failure in placing a surgical airway was described in 10 of the specific 12 cases listed in the Appendix of this Anesthesiology closed claims study, as follows:
Case 1: “Eventually a surgical airway was performed after the patient arrested.”
Case 2: “A surgical airway was performed after the patient arrested.”
Case 3: “The surgeon was called to the room to perform an emergency surgical airway, but there were not any instruments available in the room. The patient sustained anoxic brain injury and later died.”
Case 4: “Ventilation was difficult and the patient arrested. The surgeon arrived and attempted to perform an emergency surgical airway, at which time the anesthesiologist successfully intubated the patient’s trachea as the hematoma was drained. The patient was resuscitated but later died of anoxic brain damage.”
Case 5: “The anesthesiologist asked the surgeon to perform an emergency cricothyrotomy. However, the surgeon insisted that an electrocautery to be set up first. Nine minutes after cardiac arrest, a surgical airway was secured by the surgeon. The patient was resuscitated but remained in a persistent vegetative state.”
Case 6: “An ear-nose-throat surgeon was called to perform a surgical airway, who suggested a supraglottic airway be inserted instead. After the supraglottic airway was placed, the patient became impossible to ventilate and went into cardiac arrest. The surgical airway was placed with some difficulty. The patient sustained severe hypoxic brain and died.”
Case 8: “The surgeon performed a cricothyrotomy after the patient had marked bradycardia and hypotension.”
Case 10: “A surgeon was called to place a cricothyrotomy. The patient was resuscitated but had severe anoxic brain damage and died.”
Case 11: “Multiple intubation attempts and supraglottic airway insertion were made for more than an hour before a surgical airway was performed. At that time, the patient was asystolic and had a tension pneumothorax. The patient died.”
Case 12: “The patient had a hypoxic cardiac arrest. The surgeon arrived 22 min after induction and secured an emergency surgical airway. The patient was resuscitated but sustained hypoxic brain damage requiring assistance with activities of daily living.”
It’s tragic that 10 of the 12 listed cases involved delayed or failed front of neck access to the airway. In an editorial in the same issue of Anesthesiology, authors Takashi and Hillman wrote, “Decision to provide a surgical airway was frequently delayed by repeated attempts at tracheal intubation, anesthesia care providers being hesitant to initiate surgical procedures, or surgeons being reluctant to perform tracheostomy or simply not available.”
The American Society of Anesthesiologists Difficult Airway Algorithm, shown below, clearly describes invasive airway (i.e. surgical airway) access via the front of the neck when attempts to intubate the trachea and oxygenate the patient both fail.
“Can’t intubate, can’t oxygenate” events are rare, but they do occur with a published incidence of 1 in 50,000 anesthetics, per the fourth national audit project in the United Kingdom.
Approaches to front of neck access include either cannula techniques or surgical techniques, with significant differences:
This involves inserting a large bore IV catheter through the cricothyroid membrane.
Because the lumen of a 14-gauge IV catheter is small, ventilation requires a high-pressure jet oxygen delivery system. In a publication from 2016, the failure rate with cannula techniques was 42% in “can’t intubate, can’t oxygenate” emergencies. Failure can occur because of kinking, malposition, or displacement of the needle/cannula. Because of the high failure rates, use of the cannula technique is discouraged.
Most surgeons are trained to perform tracheostomies during their residencies, but when a “can’t intubate, can’t oxygenate” emergency occurs, tracheostomy is not the preferred procedure.
Cricothyroidotomy, a technique which is faster and requires less surgical skill, can be performed by anesthesiologists, and is the preferred procedure.
In a cricothyroidotomy, the cricothyroid membrane is divided by a surgical incision made with a wide scalpel (#10 scalpel).
Using the scalpel, bougie, tube (SBT) technique,
a bougie is inserted into the trachea through the incision. A lubricated 6.0 mm cuffed endotracheal tube is advanced over the bougie into the trachea, and the bougie is removed as demonstrated in this video link:
This technique has been specifically endorsed in the United Kingdom in the algorithm from their Difficult Airway Society. The British Difficult Airway Society guideline for a Can’t Intubate, Can’t Oxygenate crisis follows:
How to train anesthesiologists to perform SBT cricothyroidotomy:
Are anesthesiologists trained to perform cricothyroidotomy? Not really. Even though the procedure is the last safety valve on the Difficult Airway Algorithm, most anesthesiologists have minimal or no experience in this life-saving procedure. How can we train anesthesiologists to perform cricothyroidotomies?
In my residency in the 1980s we were trained to do cricothyroid injections of cocaine prior to awake fiberoptic intubation procedures. Each resident performed dozens of these injections, and I became extremely comfortable locating and piercing the cricothyroid membrane with a needle. In 35 years and 25,000+ anesthetics, I’ve never needed to place a surgical airway through that same membrane, but I feel confident I could do so with the scalpel, bougie, tube technique.
The problem is that most anesthesiologists have never had to perform this front of neck access procedure on a patient. The stakes are high, because there is little time for failure. After several minutes of “can’t intubate, can’t oxygenate,” someone needs to take a scalpel to the cricothyroid membrane. That someone can and often should be the anesthesiologist.
In the October 2013 American Society of Anesthesiologists Monitor we read, “Perhaps the most important problem encountered in “can’t intubate, can’t oxygenate” is a delay in recognition or institution of emergency airway management. . . . While someone clearly needs to make the decision to obtain a surgical airway, both the surgeons and the anesthesiologist may feel uncomfortable in this role. Retrospective studies, including closed claims analysis, demonstrate that most patients are already in cardiac arrest before emergency invasive airway attempts are performed. While decisive and timely action is clearly needed, the decision to pursue a surgical airway is not an easy one; . . . In fact, there is little legal risk from a surgical airway attempt – no matter how messy – if the patient survives, but enormous liability if the procedure is not attempted.”
In a study from Great Britain, 104 anaesthetists received a structured training session on performing cricothyrotomy. These anaesthetists then took part individually in a simulated “can’t intubate, can’t oxygenate” event using simulation and airway models, to evaluate how well they could perform front‐of‐neck access techniques. First‐pass tracheal tube placement was obtained in 101 out of the 104 cricothyroidotomies (p = 0.31). They concluded that anaesthetists can be trained to perform surgical front of neck access to an acceptable level of competence and speed via simulator training.
What needs to happen? Anesthesiology residents need to be trained to do front of neck access, and they need to be trained not to delay if the procedure is indicated. This training needs to be a requirement for all anesthesia professionals. Mid-career anesthesiologists pay for weekend Continuing Medical Education courses on subjects such as ultrasound-directed regional blocks or transesphogeal echocardiography. While these topics are important, they are not life-saving skills such as front of neck access. Anesthesiologists in training, practicing anesthesiologists, and Certified Registered Nurse Anesthetists (CRNAs) must receive hands-on education on performing front of neck access, as well as the reasoning behind not delaying the procedure.
You’re an anesthesiologist or a CRNA. What should you do now?
- Familiarize yourself with the anatomy of the cricothyroid membrane on each of your patients.
- Have a scalpel, bougie, tube kit containing a #10 scalpel, a bougie, and a #6 cuffed endotracheal tube included with each difficult airway cart at each facility you anesthetize at.
- I now carry a scalpel, bougie, tube kit in my briefcase which I take with me every day at work. In the current model of private practice in California, where we work at multiple different freestanding surgery centers and surgeon offices, this is a reliable means to assure that I have front of neck access equipment with me wherever I anesthetize patients.
- Review and rehearse the anatomy and skills necessary to perform front of neck surgical cricothyroidotomy.
- Work to avoid “can’t intubate, can’t oxygenate” events. Evaluate each airway prior to surgery. If a significant concern exists regarding a difficult intubation, a difficult mask ventilation, or difficult front of neck access, use your judgment and perform an awake intubation. Securing an airway prior to anesthesia induction is a reliable way to avoid “can’t intubate, can’t oxygenate” disasters.
The closed claims study on difficult tracheal intubation in the October 2019 issue of Anesthesiology should serve as a bellwether for our profession. The practices of waiting for surgeons to arrive to do front of neck access, or of anesthesiologists delaying front of neck access in a “can’t intubate, can’t oxygenate” emergency must cease. Emergency front of neck access must be a core skill that all anesthesiologists are both willing and able to perform when a patient is turning purple before their eyes.
We owe it to our patients to be ready to save their lives.
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