To the Editor
In 2006, the APSF convened a conference on the dangers of postoperative opioids.1 Although there was a consensus on improving monitoring and education, there was unanimous agreement that a policy of zero tolerance to patient harm from postoperative respiratory depression due to opioids should be adopted by all health care providers.
Almost 3 years later, I continue to receive medical records for expert review in tragic cases of “unexplained” cardiopulmonary arrest (CPA), followed by anoxic brain injury and death in postoperative patients receiving opioids. My anecdotal experience is reinforced by the “Sixth Annual HealthGrades® Patient Safety in American Hospital Study,” dated April 2009, which found “failure to rescue”, and postoperative respiratory failure as the #1 and #3 most common “medical errors” in Medicare patients.2 Failure to rescue is defined as a death of a surgical inpatient with treatable complications.
New data from a comprehensive literature review on parameters that trigger rapid response teams (RRTteams widely implemented in US hospitals to anticipate clinical deterioration prior to CPA) suggest respiratory derangements, such as tachypnea, bradypnea, and desaturation, are the predominant triggers for RRT.3 Another study finds respiratory depression as the most common etiology of a code blue emergency in patients receiving opioids at an academic hospital.4
My unpublished case series of 15 gives me valuable insights into the etiology of these sentinel events. Infrequent patient monitoring, with intervals as far apart as every 4 hours on the first postoperative night, is a major reason for the persistence of these events. “Failure to rescue” is a misnomer, since it is not a failure of the code team to resuscitate but a “failure to recognize” respiratory decompensation in a timely fashion. Long monitoring intervals allow hypoxia, hypercarbia, and changes in mental status to go undetected to the point that naloxone and epinephrine are no longer effective.
Secondly, misconceptions about the safety mechanisms of patient controlled analgesia (PCA) persist, and are largely attributed to a lack of education. Nurses have testified that the lockout mechanism and hourly opioid limit on the PCA machine is a foolproof safeguard against a patient from receiving “too much pain medicine.” Physicians testify that the opioid regimen prescribed in a sentinel event was “within normal limits.” Any opioid dosing regimen is not a “normal” regimen but a “starting” regimen, which must be titrated to optimum pain relief by frequent and meticulous clinical assessment, without suppressing respiratory drive to dangerous levels. Physicians experienced in acute pain management know this can be a delicate and time consuming task, more so now that as many as 12.5 million people in the US take opiates for nonmedical use, and many multiples thereof take opiates for chronic ailments.5 The belief that opioid-induced respiratory depression occurs only in opioid naïve patients is a fallacy. Chronic opiate users offer difficult acute pain management challenges, requiring dosages and delivery systems well outside of “normal limits.” They are predisposed to central sleep apnea and ataxic breathing, which may become decompensated postoperatively in the presence of residual anesthetics and sleep deprivation.6 These patients are frequently involved in sentinel events. Lastly, despite the JCAHO Sentinel Event Alert on PCA by proxy, the ability of someone other than the patient to hit the PCA button, remains a dangerous safety flaw in the PCA system.
Awareness under anesthesia (AUA) is a serious adverse event that has received much attention in the literature as well as the lay press. Although the BIS monitor was approved in 1996, its use did not become widespread in the US until 2003 when the FDA cited its value in preventing a “debilitating medical error.”7 Awareness during anesthesia is thought to occur 20,000 to 40,000 times per year in the US.8 Hypothetically, if we assume 30% of the 350,000 to 750,000 CPAs a year are respiratory in origin, and 30% of these involve respiratory depression due to opioids and sedatives, one could deduce that a monitor that may reduce the risk of death or anoxic brain injury in 30,000 to 70,000 patients would be eagerly deployed. Yet only a tiny fraction of hospitals have implemented continuous respiratory monitoring with central surveillance. Although the few clinical studies relating continuous monitoring to improved outcomes are contradictory,9,10 many institutions that have implemented this technology offer testimonials of “near misses” or “saves” with their systems. Technical improvements that minimize false positive alarms, as well as the real time analysis of multiple, continuous physiologic channels using “smart alarms” are rapidly overcoming the limitations of earlier equipment. If institutions countrywide adopted the technology, the economies of scale would lessen the capital equipment expenditure that remains an impediment to implementation.
But the call from the APSF Committee for more “aggressive monitoring, better education, and increased outcomes research” in 2006 has gone largely unheeded.
Throm a comprehensive literature review on parameters that trigger rapid response teams (RRT- teams widely implemented in US hospitals to anticipate clinical deterioration prior to CPA) suggest respiratory derangements, such as tachypnea, bradypnea, and desaturation, are the predominant triggers for RRe problem persists in the “blind spot” of the anesthesia closed claims database, because surgeons are most often responsible for acute postoperative pain control and the hospital for monitoring; thus, anesthesiologists are rarely named in a suit. It persists in hospitals of all shapes and sizes, as my sample includes sentinel events from small community hospitals to flagship academic medical centers.
There are glimmers of hope. A coalition of medical centers, industry, and nonprofit associations comprising the San Diego Patient Safety Task Force issued a “toolkit” on PCA Guidelines of Care that reduces the longest assessment interval from 4 hours to 2 hours.11 The lay press has noted the failure to rescue as the major patient safety issue.12 But this issue has not received the attention in the national media that AUA has received. Unlike AUA, there are no traumatized survivors for the morning talk show, only distraught families wondering what happened to their loved ones, who are told that this is a “very unusual event.”
A system-wide, multidisciplinary overhaul of the monitoring standards on our hospital general care floors is needed. Pronovost and colleagues have suggested that medicine emulate a successful commercial aviation public-private partnership, which has greatly improved the safety of the flying public.13 Given that the chance of dying on flight of a US air carrier is approximately 1 in 22 million, whereas the chance of death or serious injury upon walking into a US hospital is 1 in 90, that may be an excellent suggestion to consider for urgent implementation.
Frank J. Overdyk, MSEE, MD
Disclosure: Dr. Overdyk is a paid consultant to several monitoring and pharmaceutical companies.
- Weinger MB. Dangers of postoperative opioids: APSF workshop and white paper address prevention of postoperative respiratory complications. APSF Newsletter 2006-07;21:61, 63-7.
- The Sixth Annual HealthGrades in Patient Safety in American Hospitals Study. HealthGrades Inc., 2009. Available at: http://www.healthgrades.com/media/dms/pdf/PatientSafetyInAmericanHospitalsStudy2009.pdf. Accessed December 28, 2009.
- Alian A, Rafferty T. Evaluation of rapid response team flag-alert parameters. STA Annual Meeting Abstracts, 2009: 7. Available at: http://www.anestech.org/media/Publications/Annual_2009/2009_STA_Abstracts.pdf. Accessed December 28, 2009.
- Fecho K, Joyner L, Pfeiffer D. Opioids and code blue emergencies. Anesthesiology 2008;109:A34.
- Department of Health and Human Services, Food and Drug Administration: Docket No. FDA-2009-N-0143, Risk Evaluation and Mitigation Strategies for Certain Opioid Drugs; Notice of Public Meeting. Available at: http://edocket.access.gpo.gov/2009/pdf/E9-8992.pdf. Accessed December 28, 2009.
- Walker JM, Farney RJ, Rhondeau SM, et al. Chronic opioid use is a risk factor for the development of central sleep apnea and ataxic breathing. J Clin Sleep Med 2007;3:455-61.
- Wikipedia: Bispectral index. Available at: http://en.wikipedia.org/wiki/Bispectral_index. Accessed December 28, 2009.
- Avidan MS, Zhang L, Burnside BA, et. al. Anesthesia awareness and the bispectral index. N Engl J Med 2008;358:1097-108.
- Watkinson PJ, Barber VS, Price JD, et al. A randomised controlled trial of the effect of continuous electronic physiological monitoring on the adverse event rate in high risk medical and surgical patients. Anaesthesia 2006;61:1031-9.
- Blike G, Avery J, Mastanduno M, et al. Continuous pulse ox impacts early detection of physiological abnormalities in post-surgical patients. Anesthesiology 2008;109(Suppl 1):A30.
- Patient Controlled Analgesia Guidelines of Care for the Opioid Naïve Patient. Available at: http://www.hasdic.org/documents/Tool-Kit-PCA.pdf. Accessed December 28, 2009.
- Aleccia J. Before code blue: who’s minding the patient? msnbc.com: Healthcare. Available at: http://www.msnbc.msn.com/id/24002334. Accessed December 28, 2009.
- Pronovost PJ, Goeschel CA, Olsen KL, et al. Reducing health care hazards: lessons from the commercial aviation safety team. Health Aff (Millwood) 2009;28:479-89.