To the Editor:—
It is hard to measure the intangibles of skilled anesthesia management such as leadership, planning, and dynamic problem solving, let alone to link them unequivocally to specific patient outcomes. Although simulation training has been advanced as a method to help develop crisis management and other “nontechnical” skills, proof of this link is currently incomplete.1–3However, a recent example may highlight the value of simulation training during anesthesia residency with respect to these issues. On a recent international medical trip, the operating room's sole oxygen supply, an H-cylinder, was accidentally knocked over, severely damaging its regulator and causing a high-pressure leak necessitating its immediate removal. Because oxygen was the only gas supplied to the anesthesia machine, all fresh gas flow to the anesthetized and paralyzed patient ceased, and the oxygen supply alarm sounded.
Options at this point included (1) hand ventilation through the circuit (taking advantage of a functional carbon dioxide–absorbing system), but diluting the alveolar anesthetic level and risking wastage of oxygen through small leaks in the circuit, or (2) apneic oxygenation from a quiescent circuit. The latter was chosen, because it would be the means most likely to maintain alveolar anesthetic and oxygen levels while freeing hands to prepare for an intravenous anesthetic. Accordingly, further ventilation was temporarily suspended, and the sidestream carbon dioxide sampling line was disconnected and capped (so as not to waste oxygen from the circuit). Fortunately, a pulse oximeter was available.
The personnel management of this situation focused on dispatching others to obtain a self-inflating ventilation bag from the recovery room (the one and only such device in the entire hospital) and making preparations for an intravenous anesthetic, while seeking a replacement for the damaged oxygen pressure regulator. In this particular event, the patient experienced 6–7 min of apnea and remained anesthetized while maintaining oxyhemoglobin saturations of 100%.
When faced with an oxygen supply loss, the near explosion of an unsecured cylinder, and a loud alarm, one's first instinct may be to vigorously ventilate the patient. However, by closing the pressure relief valve and discontinuing sidestream carbon dioxide analysis, one can ensure a 4- to 15-min oxygen supply (depending on fraction of inspired oxygen, functional residual capacity, and patient metabolism). It is not clear how long it would have taken to sort through these options from first principles under these difficult conditions without previous exposure to a similar problem during a crisis simulation course in residency (Anesthesia Crisis Resource Management, Stanford University School of Medicine, Stanford, California).4–6In this course, trainees manage both common and novel operating room complications, allowing them to develop templates for technical and behavioral responses to such situations. The use of high-fidelity human patient simulators and recreated operating room environments in courses such as this capture both the stress and the immediacy of real patient emergencies and, ideally, provide the first exposure to plausible catastrophes in a setting where no patients' lives are at risk. When a potentially catastrophic oxygen supply failure arose in real life, its management seemed relatively routine because, virtually speaking, I'd been there before.
Stanford University School of Medicine, Stanford, California. firstname.lastname@example.org