A Cause for Alarm(s)

by Ann S. Lofsky, MD, Anesthesia Consultant and Governor Emeritus

When an adverse outcome occurs in medicine and a patient is injured, a malpractice claim may be filed even though the physicians involved followed acceptable standards of care for their specialties. Sometimes many such claims accumulate—all with strikingly similar characteristics. When this occurs, it is possible that there are system errors in the practice of the entire specialty that might be leading to claims instead of simply isolated acts of negligence on the part of individual physicians. If a system problem is identified, The Doctors Company may ask our patient safety/risk managers or an expert reviewer to suggest practice changes that would prevent similar occurrences, improve patient safety, avoid malpractice claims, and, as in the situation described below, possibly save lives.

Following a fall on his motorcycle, an overweight 22-year-old male presented to the emergency room with a compound fracture of the tibia. A history and physical examination, performed by an internist, reported that he smoked one pack of cigarettes a day and carried the diagnosis of mild sleep apnea. He was taken to the operating room the next morning for an open reduction and internal fixation of the leg that was accomplished under general anesthesia without difficulty.

For postoperative pain relief, the surgeon ordered meperidine 75 mg intramuscularly every four hours as needed, but as soon as the man arrived on the ward, he began to complain of severe pain. The anesthesiologist was contacted and a morphine patient-controlled analgesia pump (PCA) was ordered, with the patient able to self-administer doses of 1 mg every six minutes. One hour later he was still complaining of pain rated as 9/10. The anesthesiologist ordered a change in the bolus dosage to 2 mg every 10 minutes as needed.

According to the nursing notes for 3 p.m. that afternoon, the patient was resting comfortably. He slept throughout the night without complaining, although his loud snoring caused several other patients on his ward to complain that the noise was keeping them awake. At 7 a.m. the next morning, a nurse making routine rounds found the man cold and unresponsive in bed. A code was called, but the patient could not be resuscitated. He was pronounced dead at 8:15 a.m.

Was There Any Negligence Involved in the Care of This Patient?

An autopsy was performed, revealing no obvious cause of death. While the plaintiffs initially alleged narcotic overdosing, a full toxicology panel obtained during the code revealed only morphine present in the man’s blood at a “low therapeutic” level. Blood gases obtained at the same time revealed a markedly elevated carbon dioxide level, suggesting that the man had not been breathing for quite some time before he was discovered. Nursing notes, however, showed that all scheduled vital signs had been recorded (every four hours), always falling within normal ranges before the time of the arrest.

The defense experts found no deviations from the standards of care for the surgeon, the anesthesiologist, or the nurses. While the plaintiffs argued that a healthy young man would not die without negligence, many reviewers felt that this was simply a tragic but unavoidable outcome under the circumstances.

What If Many Similar Claims Were Seen?

By 2001, The Doctors Company had reviewed at least eight claims following postsurgical deaths in patients with known or suspected sleep apnea. The claims all involved patients who died on hospital wards while receiving parenteral narcotics for pain. An expert review panel was held, resulting in The Doctors Company’s patient safety alert “Sleep Apnea and Narcotic Postoperative Pain Medication: A Morbidity and Mortality Risk.”¹ That article was later reprinted by the Anesthesia Patient Safety Foundation Newsletter,² and a link to The Doctors Company’s article was placed on the Web site of the American Sleep Apnea Association.³

What Can Be Done to Prevent Deaths Like These?

Concerned about the adequacy of postoperative monitoring for patients receiving opiates through PCAs and neuraxial analgesia (spinals and epidurals), the Anesthesia Patient Safety Foundation (APSF) organized a workshop in October 2006 to discuss the problem. Presenters at the workshop included researchers on opiate-induced respiratory depression and experts on the function of capnography and pulse oximetry. Also presented were reviews of malpractice claims by The Doctors Company and a representative from the American Society of Anesthesiologist’s Closed Claim Study (in which The Doctors Company participates).

From the sleep apnea claims reviewed by The Doctors Company, it appears that respiratory rate alone was an insufficient monitor for these patients. According to what is known about the pathophysiology of sleep apnea, this was not an unexpected finding. During periods of obstruction, patients with obstructive sleep apnea (OSA) exhibit continued respiratory effort that can be difficult to differentiate from effective respiration by visual means alone. In contrast to the centrally mediated hypopnea and apnea associated with narcotic overdosage, obstructive apnea is rarely associated with slow respiratory rates. Episodes of critical obstruction may occur sporadically, only minutes after a normal respiratory rate has been observed. The consensus of the workshop participants was that continuous monitoring may be indicated for at-risk patients, including those with suspected or diagnosed OSA.

On the topic of which continuous monitor would be most appropriate for this indication, it was felt by those at the workshop that all existing monitors have some advantages and drawbacks—but that awaiting the perfect monitor is not an acceptable alternative. Pulse oximetry is a time-tested monitor of oxygenation, but when patients are receiving supplemental oxygen by mask or nasal cannula, there may be a significantly prolonged period of apnea before saturation falls, allowing carbon dioxide to climb to dangerous levels. When supplemental oxygen is being administered, additional monitors of ventilation (such as exhaled carbon dioxide) might be indicated. It was the feeling of participants at this meeting that in order to be effective, the monitoring must be linked to a system for summoning a caregiver promptly to a patient’s bedside. The final APSF statement reads in part: “APSF urges healthcare professionals to give consideration to the potential safety value of continuous monitoring of oxygenation (pulse oximetry) and ventilation in patients receiving PCA or neuraxial opioids in the postoperative period.” The full text of the APSF bulletin can be found on its Web site.⁴

As pain alleviation has become a more important therapeutic goal—both for patients and physicians—injuries relating to postoperative narcotics have increased, but there is now a general feeling that this is a preventable cause of morbidity and mortality. As one of the largest insurers of anesthesiologists in the United States, The Doctors Company plans to continue working with the APSF and other anesthesiology organizations to prevent complications in the perioperative period.

References