The Case

An 80-year-old man with a history of coronary artery disease and atrial fibrillation underwent a combined elective coronary artery bypass graft (CABG) and Maze procedure (ablation of atrial fibrillation). A pulmonary artery (PA) catheter was placed after induction of anesthesia in order to closely monitor the patient's hemodynamic status. The surgery was proceeding uneventfully when the surgeon requested that the PA catheter be pulled back from the pulmonary artery into the right ventricle when he performed the actual ablation. At that point, the surgeon was informed that another patient in the cardiac intensive care unit (ICU) would require an emergency CABG. The surgeon was the only cardiac surgeon available that day, and there was also only one cardiac anesthesia team. The surgeon and attending anesthesiologist decided to begin the emergency CABG as soon as possible after completing the current procedure.

The remainder of the CABG was completed without incident, and the patient was weaned off cardiopulmonary bypass (CPB) easily, but this process took nearly another hour. By this point, the second patient was already being brought to another operating room (OR), and the team had received several pages about his clinical status. The surgeon was anxious to start the second case as soon as possible, so in order to speed up the transfer process, the attending anesthesiologist refloated the PA catheter himself back into the pulmonary artery, which required re-inflating the catheter's balloon. As soon as this was completed, the anesthesiologist rushed to the other OR in order to begin the emergency CABG. An anesthesia resident accompanied the first patient to the ICU.

In the ICU, the nurse who assumed care of the patient noticed that the PA catheter waveform was dampened (the tracing was flat and did not vary with the cardiac cycle). Further check by him and the anesthesia resident revealed that the PA catheter balloon was still inflated, and probably had been so the entire time after refloating. This was potentially very dangerous, as leaving the balloon inflated could have caused catastrophic damage to the pulmonary artery. Fortunately, the nurse recognized the situation quickly, and the resident deflated the balloon and withdrew the PA catheter without the patient experiencing any harm. The anesthesia resident realized that she had not discussed the PA catheter explicitly (including its inflation status) with the attending prior to transferring the patient out of the OR.

The Commentary

Pulmonary artery (PA) catheter insertion and monitoring was very common during anesthesia for cardiac surgical cases 20 to 40 years ago. Today, their use is much less common, in part because of questions about their utility, but much more so because of the introduction and widespread adoption of intraoperative transesophageal echocardiography during cardiac surgery. Echocardiographic direct observation of cardiac valvular function, volume of blood in the heart, and myocardial contractility allows evaluation of the surgical repair and also titration of anesthetic and hemodynamics-targeted medications in real time. However, data from a PA catheter can still be valuable in managing certain difficult perioperative situations.

One comprehensive guideline on pulmonary artery catheters (1) provides an overview. Indications for PA catheter monitoring continue to be debated. Benefits include measurement of important parameters (e.g., PA occlusion wedge pressure [an indirect indication of left atrial pressure, a surrogate for left ventricular function], cardiac output, and mixed venous oxygen saturation), which can give more objective assessment of the hemodynamic status of critically ill patients than is possible by clinical evaluation alone. In surgical patients, PA catheter data often can reveal unfavorable developments that need treatment. Preoperative PA catheter data can be helpful in determining whether it is safe for high-risk patients to proceed with surgery.

Unfortunately, PA catheterization can also have important adverse effects. Catheter insertion can result in arterial injury and related hematomas, hemopneumothorax, and dangerous dysrhythmias. The catheter can cause potentially fatal PA hemorrhage from balloon over-inflation causing arterial rupture, endocardial damage, thromboembolism, or sepsis. The data provided by a PA catheter is also complex and subject to misinterpretation, especially since PA catheters are used much less often than before.

One important tenet of PA catheter use has always been strict avoidance of permanent wedging, usually with the balloon tip inflated, because of the acute risk of pulmonary artery rupture, or, with enough time, pulmonary infarction in the distribution of the occluded artery. Therefore, in the case described here, the prolonged inflation of the PA catheter balloon was indeed very dangerous. It is a tribute to the ICU nurse that the danger was recognized and corrected.

The fundamental patient safety teaching point of this case concerns why the PA catheter balloon was inappropriately left inflated. Major accidents virtually always involve two or more variations from normal, coincident in time. These often occur in a manner creating a situation never seen before by the involved personnel, thus invalidating pattern recognition that commonly triggers a corrective response to typical abnormalities. An extension of this concept was articulated in Reason's Swiss-Cheese Model (2,3) in which the lining up of the holes in safety barriers allows progression to patient injury via the multiple situational or behavioral deviations occurring in sequence and, thus, failing to stop the injurious flow of events.

In the case presented here, attention to routine details by both the surgeon and the attending anesthesiologist was diverted by the announcement of an additional emergency case to follow as soon as possible and, then, the repeated arrival of additional reports about that new patient's status. The attending rushed away, obviously without giving a complete update to the resident left to complete the final segment of the case. Further, whether the resident remaining was experienced enough to recognize the permanently wedged PA catheter is unknown, but this could represent a compounding knowledge deficit component of human error. This type of rushed and difficult circumstance places a high premium on comprehensive, accurate communication, to help avoid the type of oversight error that did occur. Having clinicians thrust into an emergency "hurry-up" situation should be a red flag that leads to recognition of the danger of such production pressures. In response, clinicians should slow down their pace, becoming more deliberate than normal as they complete the current task before turning to the new one. However, the drama of high-powered expert clinicians rushing off to try to save a life is seductive. Accordingly, development and implementation of communication tools may be needed to help prevent the types of error seen in this case.

A comprehensive review declared: "Communication breakdowns are a common cause of surgical errors and adverse events."(4) While it is valid to suggest that the attending anesthesiologist should have known better and given a complete report to the resident (including a review of the current hemodynamic data on the monitor screen, which would have revealed the error), some degree of human error in dynamic situations is inevitable. The purpose of communication tools as cognitive aids in such circumstances is to help prevent human errors, including oversights and knowledge deficits. The handover from one caregiver to another is a very vulnerable time, exposed to errors both of omission and commission. Cognitive aids in the past have sometimes been in the form of mnemonics (e.g. iSoBAR (5), a handover protocol incorporating the following components: identify–situation–observations–background–agreed plan–read back). However, more recent and favored strategies involve formal checklists.

The efficacy and value of checklist use by professional pilots in aviation is well known (6) and widely studied. In a medical care setting, a critical care handover formal checklist can be completed rapidly when necessary. Whether paper-based or screen-based, a handover checklist covers a patient's basic demographic, care to date, current status (including monitor values), and plans for care. Slight differences may occur between checklists for intraoperative handover between anesthesiologists and immediate postoperative handover from anesthesiologist to post-anesthesia care unit or ICU caregivers, and the literature is replete with examples from various institutions. One thoughtful review (among many) concludes: "...robust, structured handover processes are critical for safe patient care."(7) Checklists of the type applicable to this case have been published about pediatric cardiac surgery in particular.(8,9) It seems likely that in this case, utilization of a handover checklist at the time the attending anesthesiologist turned over responsibility to the resident would have discovered the PA catheter error and prompted its early correction.

The value of checklists in surgical care has been amply illustrated by the global impact of the Surgical Safety Checklist from the World Health Organization (10), an on-going project chaired by patient safety authority and researcher Dr. Atul Gawande.(11) This comprehensive 19-item list has three sections for three key time points in the patient's surgical experience: before induction of anesthesia, before skin incision, and before the patient leaves the operating room. The efficacy of this approach and this specific checklist in preventing adverse patient events has been demonstrated.(12) Predictably, there can be resistance by personnel in the surgical arena to the adoption and consistent practice of any checklist, even one that takes less than a minute to execute at each time point. Those interested in improving safety must understand that checklist implementation is a complex sociotechnical process that requires a robust culture of safety as well as extensive preparatory work to ensure checklists can be integrated into clinician's workflow; otherwise, checklists may wind up gathering dust (literally and metaphorically). Importantly, experience teaches that it takes only one patient save in which an impending injury was prevented by application of the checklist (or a near-miss when it was ignored) to convert the involved professionals into believers who implement, utilize, and even preach the Surgical Safety Checklist.

While it is tempting to look at a case like this and focus only on understaffing or production pressures, there will always be high stress circumstances in the intense operating room and perioperative environment. The thoughtful integration of handover checklists (here, in particular, at the transition between anesthesiologists), combined with a strong safety culture, can ensure that all steps in a process and factors in a critical clinical situation are attended to—even when time is tight.

Take-Home Points

• Pulmonary artery catheters may still be used in cardiac surgery cases, but they have been largely supplanted by real-time transesophageal echocardiography. One of the greatest dangers of their use is a permanent wedge with the balloon inflated that can cause severe pulmonary artery or lung injury.
• Production pressure from any source, but especially unplanned emergency demands, can distract anesthesiologists and surgeons during and after an operative procedure enough to disrupt usual practices and lead to an adverse patient outcome.
• Under all perioperative circumstances, but particularly with dangerously increased production pressure, cognitive aid from planned organized handover checklists for transitions among caregivers can clearly help prevent accidents from oversights or knowledge deficits.
• For surgical care in general, the World Health Organization Surgical Safety Checklist is an extremely valuable tool that has been proven to help reduce patient morbidity and mortality.
• Automatic resistance to the implementation of checklists (it's a change, a possible slight increase in time and effort, a bureaucratic exercise, etc.) occurs—until caregivers are involved in prevention of a patient injury through use of a checklist.

John H. Eichhorn, MD Professor of Anesthesiology, College of Medicine Provost's Distinguished Service Professor University of Kentucky Lexington, KY

References

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2. Reason JT. Understanding adverse events: human factors. Qual Health Care. 1995;4:80-89. [go to PubMed]

3. Reason JT. Human error: models and management. BMJ. 2000;320:768-770. [go to PubMed]

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5. Porteous JM, Stewart-Wynne EG, Connolly M, Crommelin PF. iSoBAR—a concept and handover checklist: the National Clinical Handover Initiative. Med J Aust. 2009;190(suppl 11):S152-S156. [go to PubMed]

6. Degani A, Wiener L. Human Factors of Flight-Deck Checklists: The Normal Checklist. Moffett Field, CA: Ames Research Center, NASA; 1990. NASA Contractor Report 177549. [Available at]

7. Kalkman CJ. Handover in the perioperative care process. Curr Opin Anesthesiol. 2010;23:749-753. [go to PubMed]

8. Zavalkoff S, Razack S, Lavoie J, Dancea AB. Handover after pediatric heart surgery: a simple tool improves information exchange. Pediatr Crit Care Med. 2011;12:309-313. [go to PubMed]

9. Craig R, Moxey L, Young D, Spenceley NS, Davidson MG. Strengthening handover communication in pediatric cardiac intensive care. Paediatr Anaesth. 2012;22:393-399. [go to PubMed]

10. World Alliance for Patient Safety. WHO Surgical Safety Checklist and Implementation Manual. [Available at]

11. Gawande A. The Checklist Manifesto: How to Get Things Right. New York, NY: Metropolitan Books; 2009. ISBN: 9780805091748.

12. Haynes AB, Weiser TG, Berry WR, et al. A surgical safety checklist to reduce morbidity and mortality in a global population. N Engl J Med. 2009;360:491-499. [go to PubMed]