Intraoperative Code

An 80 year old debilitated patient with heart disease, congestive heart failure, chronic obstructive pulmonary disease, and diabetes presents to an outside hospital with progressive weakness, fevers, hypotension, and tachycardia. An MRI of the spine shows an epidural abscess, infection of the area outside the spinal cord. He is intubated, started on antibiotics and vasopressors, and transferred to Stanford.

He goes to the operating room for an extensive multilevel spine surgery. I was not the anesthesiologist for this procedure so I don't know all the details. As the day progressed, the patient's blood pressure became lower and lower, requiring a constant infusion of phenylephrine. Near the end of the case, his heart stopped. His EKG was a flatline - asystole. The surgeons started chest compressions and the anesthesiologist ran the code. After several rounds of epinephrine and commencement of inhaled nitric oxide, the patient's heart returned. I was called to provide additional assistance. We brought the patient down to CT scan, concerned about a pulmonary embolism, but didn't find a massive saddle embolus. On transesophageal echocardiogram, the right ventricle was stunned, but we didn't know the cause. Despite active investigation, we didn't know why the cardiac arrest happened.

I write this post because we want to know the cause of a cardiac arrest, but rarely find a single certain etiology. When something this serious happens, we want to pinpoint what happened, both for the patient's treatment and for our peace of mind. Was this something we could have prevented or avoided? Was it inevitable? Did we miss something? Are we treating the patient appropriately?

Talking to many anesthesiologists, however, I began to realize such answers are rare. We memorize a mnemonic about the causes of cardiac arrest, but more often then not, the cause seems to be multifactorial. Here, an older patient with a significant cardiac history presents with a severe, overwhelming infection. He progresses to hemodynamic collapse and respiratory failure, requiring ventilatory support, vasopressors, and ICU admission. He was probably dehydrated at the beginning of the case, and may have been underresuscitated. Decompressing the epidural abscess may have released toxins into the bloodstream. The heart may have taken a hit. His immobility in the ICU may have made him prone to pulmonary embolism. Bleeding from an extensive case decreased his reserve. And one of these many triggers tipped him over the edge. The further I go in medicine, the more I realize this is how body and disease interact. Most critical events happen as an accumulation of small injuries suffered, not as a single event. We don't necessarily learn this in medical school, that life happens to be a little messier than textbooks.