To the Editor
Thank you for the special article, Sleep Apnea and Narcotic Postoperative Pain Medication: A Morbidity and Mortality Risk, in the APSF Newsletter.1 We anesthesia providers, it is safe to say, are uniformly concerned about the respiratory risks of administering postoperative opioids and sedatives to patients at risk of sleep apnea. We appreciate the Doctors Company for convening an advisory panel to discuss the issue.
I was surprised, however, that the “panel members were struck by the fact that all of the cases [of cardiopulmonary arrest] reviewed could have been prevented by audible pulse oximeter monitoring on the ward.”1 While I do not know of any direct evidence to support this conclusion, I can think of many reasons to question it.
The pulse oximeter has a number of limitations, especially on the general care ward where nurse to patient ratios are low. The oximeter is a “high maintenance” machine. It can be rendered useless by patient motion, probe malpositioning, failure to properly set the alarm volume and parameters, inaudibility of the alarm from the nurses’ station, poor peripheral circulation, and so forth. The machine is plagued by repetitive false positive alarms, to the point that the staff frequently silences the alarm without bothering to check its validity. Indeed, staff is more often than not unable to differentiate a valid alarm from a false one.
We need to find safe, effective, and economical means of delivering postoperative analgesia to the patient at risk for sleep apnea. Until we do, we cannot state that these deaths are preventable.
Kyle S. Fisher, MD
Boone, North Carolina
1. Lofsky A. Sleep apnea and narcotic postoperative pain medication: a morbidity and mortality risk. APSF Newsletter 2002;17:24-5.