Mark Schmidhofer

Ambiguity and Workarounds as Contributors to Medical Error

The Quality Grand Rounds series in Annals illustrates how work-system conditions can produce errors and adverse events (1). The human cost of medical error provided incentive for such studies (2-5). In one case, a nurse mistakenly used insulin rather than heparin to flush the arterial line of a patient, Mrs. Grant, causing severe hypoglycemia, seizures, coma, and, ultimately, death (6). In another, unreliable processes for identifying patients, assuring consent, and exchanging information led to a Mrs. Morris being mistaken for a Mrs. Morrison; as a result the patient was subjected to an unnecessary, potentially dangerous electrophysiologic examination (7). We ask: Do medical errors such as these have common root causes? Can lessons to improve reliability be drawn from nonhealth care organizations that overcome the potential for catastrophe brought on by work complexity, knowledge intensiveness, and variety and volatility of circumstance (8)? The answer to both questions is yes. Error-prone organizations tolerate ambiguity, a lack of clarity about what is expected to happen when work proceeds. Therefore, defining what constitutes a problem is difficult for several aspects of work. It is not perfectly clear 1) what the workgroup is trying to achieve; 2) who is responsible for what tasks; 3) how to exchange information, materials, or services; or 4) exactly how to perform tasks. Moreover, even when recognized, problems are worked around; people improvise to get the job done, even when indicators suggest something amiss. They fail to contain problems or improve processes, leaving factors that confounded one persons work to confound again. In contrast, superlative organizations design work as series of ongoing experiments by consistently specifying how to do work. Specification makes clear what is expectedwho is to be where, who should be doing what, and what results should occur. When specifications deviate from actual experience, these organizations promptly investigate the deviations to prevent them from causing harm or recurring (Table). Table. Contrasting Error-Prone and High-Performing Organizations Contributions of Ambiguity and Workarounds to Medical Errors Mrs. Grant stabilized after cardiac surgery, allowing reasonable clarity about what additional care she needed (aspect 1); who was responsible for one element of that care, flushing the arterial line (aspect 2); and the fact that her nurse knew he needed to perform that task (aspect 3)evidenced by his responding to an alarm indicating an occlusion. While there was clarity concerning how to flush the line (aspect 4), heparin and insulin were difficult to differentiate. Both were stored in vials of similar size, shape, weight, and location; and once in a syringe, the drugs are indistinguishable because they are both colorless. Lack of clarity meant that the nurse could not tell whether he had done his job correctly. As for the contribution of workarounds to the tragedy, nurses probably had previously chosen insulin rather than heparin but had corrected the error before administration. (Bates [9] estimates that incorrect drug administrations outnumber patient harm by a ratio of 100 to 1.) Switching the right drug for the wrong one, without reducing the chance of confusing the two again, preserved the potential for recurrence. Seventeen errors were identified in the Morris/Morrison case. Among these was miscommunication (aspect 3) between the nurse who was looking for Mrs. Morrison and someone who thought this nurse was seeking Mrs. Morris. Errors in task performance (aspect 4) included a nurses incorrect report that Mrs. Morrison had been transferred and the laboratorys failure to verify Mrs. Morriss identity. The danger of workarounds is evident in the decision of Mrs. Morriss care team to continue her transport despite the absence of an order or a signed consent form in her chart, and even over the patients objections. A resident caring for Mrs. Morris did not intervene when he found the laboratory doing the unexpected procedure; rather, he assumed that the attending physician had not informed him of a study, a failure in communication that had occurred before. High-Performing Systems: Specification and Immediate Problem Solving In pursuing quality, safety, productivity, and flexibility, leaders in other industries specify exactly what is expected in the 4 aspects of work described above. In so doing, they create the opportunity to be surprised, allowing workers to recognize deviations from the expectations implied by the original specification. Then, once surprised, these leaders treat discrepancies as something that is not normal and should be investigated immediately. This approach contains problems, generates knowledge, and leads to improvements. For example, aircraft carriers are dangerous workplaces because of severe weather, limited visibility, rapid changes in mission, and continuous arrivals and departures of aircraft, all needing the same limited deck space, equipment, and crew. Despite these dangers, flight operations are typically safe. Work is highly specified, even for circumstances in which a change in situation requires a change in roles. Crews color-code uniforms, demarcate spaces on the deck, and define what is to be done during launches and recoveries. Aberrations, such as someone being out of position, quickly make it obvious that operations cannot continue as if all were normal (10). Southwest Airlines is faster and more accurate than its competitors at the critical process of flight departuresdespite having to coordinate specialized employees amid the vagaries of weather, airport congestion, mechanical failures, and load fluctuations. It specifies what must be done to ensure a smooth departure and also to make it evident even when the situation has changed (and thereby requiring a different but also specified plan) (11). Toyotaa leader in the complex work of product design (12, 13), new-model introduction (14), and production (15, 16)specifies how work is to be done so that even small deviations from expectations (whether in routine work or in highly complex unique efforts such as new-model launches and disaster recovery [17]) are evident. Once detected, problems are promptly investigated (15, 18, 19) and contained, and information relevant to understanding them is fresh and easier to accurately reconstruct than it would be if problem solving were delayed (20-22). Examples in Health Care Some health care organizations have successfully tested highly specifying processes. The Shock, Trauma, and Respiratory intensive care unit at LDS Hospital in Salt Lake City, Utah, developed protocols to better control glucose levels, decrease nosocomial infection rates, and reduce costs. These protocols are noteworthy because once developed, they were often changed as users encountered problems applying them (23). Thompson and colleagues (24) reported on how hospitals reduced ambiguity and workarounds. In one hospital, on each shift nurses averaged 23 searches for keys to the narcotics cabinet; this wasted 49 minutes per shift and delayed analgesia to patients. Rather than tolerate continued searches, administrators tested assigning numbered keys at the start of each shift, with safeguards to prevent loss or misuse. This procedure nearly eliminated searches for keys and saved 2895 nurse-hours yearly in a 350-bed hospital. Another hospitals pharmacy used deviations from design to trigger process improvement, not workarounds. Without any technology investments, searches for missing medication decreased by 60% and stockouts fell by 85%. Avoiding Ambiguity and Workarounds in the Annals Cases What difference might similar procedures have made in Mrs. Grants case? The first time a nurse saw that the patient had taken a wrong drug, an investigation would have been initiated to discover why selecting the wrong item was so easy. Insulin and heparin might then have been stocked in distinctive vials or location before someone else could err again. In Mrs. Morrisons case, hospital staff would have specified a particular time for Mrs. Morrisons electrophysiologic examination (aspect 1). This would have resulted in well-specified assignments for who was responsible for transport (aspect 2), the manner in which the electrophysiology laboratory was to request the next patient (aspect 3), and how staff would identify patients and obtain consent (aspect 4). With such clarity about what was supposed to happen, staff would have seen that Mrs. Morrisons situation (being left unprepared for a test and not being transported as expected) was contrary to expectations and would have treated it as a problem. In turn, then, they would have immediately stopped work and triggered investigation, problem-solving, and process improvement. Conclusions By meticulous specification of who should supply what goods, information, or services, to whom, in what fashion, and when, problems can be identified, often before they produce adverse events. With this sort of system, the consequences of problems do not propagate, and investigations result in design changes that reduce the likelihood of recurrence. But how does one start, given that health care seems to be unique in its extraordinary complexity? Every patient presents unique features, diagnostic and therapeutic methods change quickly, the consequences of error can be profound, and the needs of several patients often must be met concurrently. Start small. There is no need to specify an entire system at once. As with the examples from Thompson and colleagues and LDS Hospital, small pieces of larger systems can be specified. As problems reveal themselves, other items that need to be specified become more evident. At the same time, the process teaches important lessons in applying and internalizing these principles. Start simple. Much of what patients require, and the fact that meeting these needs sometimes results in error,

Pharmacotherapy Update on the Use of Vasopressors and Inotropes in the Intensive Care Unit

This paper summarizes the pharmacologic properties of vasoactive medications used in the treatment of shock, including the inotropes and vasopressors. The clinical application of these therapies is discussed and recent studies describing their use and associated outcomes are also reported. Comprehension of hemodynamic principles and adrenergic and non-adrenergic receptor mechanisms are salient to the appropriate therapeutic utility of vasoactive medications for shock. Vasoactive medications can be classified based on their direct effects on vascular tone (vasoconstriction or vasodilation) and on the heart (presence or absence of positive inotropic effects). This classification highlights key similarities and differences with respect to pharmacology and hemodynamic effects. Vasopressors include pure vasoconstrictors (phenylephrine and vasopressin) and inoconstrictors (dopamine, norepinephrine, and epinephrine). Each of these medications acts as vasopressors to increase mean arterial pressure by augmenting vascular tone. Inotropes include inodilators (dobutamine and milrinone) and the aforementioned inoconstrictors. These medications act as inotropes by enhancing cardiac output through enhanced contractility. The inodilators also reduce afterload from systemic vasodilation. The relative hemodynamic effect of each agent varies depending on the dose administered, but is particularly apparent with dopamine. Recent large-scale clinical trials have evaluated vasopressors and determined that norepinephrine may be preferred as a first-line therapy for a broad range of shock states, most notably septic shock. Consequently, careful selection of vasoactive medications based on desired pharmacologic effects that are matched to the patients underlying pathophysiology of shock may optimize hemodynamics while reducing the potential for adverse effects.

Practical Implementation of the Coronary Revascularization Heart Team

Multidisciplinary decision making has been shown to be highly effective in various aspects of medicine, most notably with the concept of tumor boards and transplant committees.1 ,2 The most updated guidelines for percutaneous coronary intervention (PCI), published jointly by the American College of Cardiology Foundation, American Heart Association, and the Society for Cardiovascular Angiography and Interventions, assign a class IC recommendation for the use of a collaborative Heart Team approach in the treatment of patients with complex coronary artery disease (CAD).3 The guidelines assert that this recommendation is based on retrospective analyses showing that patients with complex CAD referred for revascularization based on a Heart Team consensus have improved mortality compared with patients merely assigned to a particular strategy in the context of their trial enrollment. Despite the suggestion of improved mortality in this retrospective comparison, the Heart Team approach has not been adopted widely in the current clinical practice of cardiovascular medicine. This multidisciplinary innovation remains in its infancy, and numerous questions remain about its practicality, feasibility, and efficacy. For several reasons, there remains significant variability in the care delivered to patients with complex CAD.4 Numerous reports show that although differences in patient characteristics may explain some of the variability in revascularization decisions, much of this variance is physician driven, such as practicing in a fee-for-service model or high-risk anatomy for low-volume operators.4,5 As emphasis grows on informed decision making and patient-centered care, a critical evaluation of these difficult questions will be essential to discovering whether there is a clinically meaningful effect of the Heart Team approach on patients with complex CAD. Although the longstanding use of tumor boards in the field of oncology represents a functioning model of interdisciplinary care on which the Heart Team may be based, it is critical …

The prognostic significance of troponin I elevation in acute ischemic stroke

BACKGROUND The significance of cardiac troponin I (TnI) levels in patients with acute ischemic stroke remains unclear. METHODS Data were prospectively collected on 1718 patients with acute ischemic stroke (2009-2010). Patients with positive TnI (peak TnI ≥0.1 μg/L) were assigned to the myocardial infarction (MI) group if they met diagnostic criteria. The remaining patients with positive TnI were assigned to the no-MI group. Patients were followed up for 1.4 ± 1.1 years. Primary outcome was inhospital and long-term all-cause mortality. RESULTS Positive TnI was present in 309 patients (18%), 119 of whom (39%) were classified as having MI. Positive TnI was independently associated with older age, hypertension, smoking, peripheral arterial disease, heart failure, higher systolic blood pressure, higher serum creatinine, and lower heart rate (P < .01). Patients with MI had the highest inpatient mortality (P < .001) and the lowest survival rate by Kaplan-Meier analysis (P < .0001). Peak TnI greater than or equal to 0.5 μg/L, particularly if satisfying criteria for MI, was independently associated with long-term mortality (P < .0001); peak TnI less than 0.5 μg/L alone was not when adjusted for covariates. CONCLUSION Positive TnI greater than or equal to 0.5 μg/L in patients with acute ischemic stroke was independently associated with worse outcomes. Patients with diagnosis of MI represent a particularly high-risk subgroup.

TROPONIN I ELEVATION IN ACUTE ISCHEMIC STROKE

Acute ischemic strokes are often accompanied by cardiac events. The prevalence, associated factors, and implications of elevated troponin I (TnI) in acute ischemic stroke merit further study. We reviewed our prospective registry of hospitalized patients with acute ischemic stroke from 2009 to 2010

Performance of Anti-Factor Xa Versus Activated Partial Thromboplastin Time for Heparin Monitoring Using Multiple Nomograms:

The purpose of this study was to compare the performance of anti-factor Xa concentration versus activated partial thromboplastin time (aPTT) monitoring with multiple indication-specific heparin nomograms. This was a prospective, nonrandomized study with historical control at a large academic medical center. A total of 201 patients who received intravenous heparin in the cardiology units were included. The prospective cohort included patients (n = 101) with anti-factor Xa (anti-Xa) monitoring, and the historical control group included patients (n = 100) who had aPTT monitoring. Patients in the prospective group had both anti-Xa and aPTT samples drawn, but anti-Xa was used for dosing adjustment. The anti-Xa cohort achieved a significantly faster time to therapeutic range (P < .01) and required fewer dose adjustments per 24-hour period compared to the aPTT control (P = .01). Results were consistent across heparin nomograms. The overall discordance rate between the 2 tests was 49%. No significant differences in clinical outcomes were observed. In summary, anti-Xa monitoring improved the time to therapeutic anticoagulation and led to fewer dose adjustments compared to the aPTT with multiple indication-based heparin nomograms.

CARDIOMYOPATHY IN ACUTE ISCHEMIC STROKE

Cardiomyopathy (CM) in patients admitted with acute ischemic stroke has not been investigated previously. A prospective registry of 1,761 patients admitted with diagnosis of acute ischemic stroke from 2009-2010 was used to identify patients with systolic CM. Echocardiography was performed on 1,594

MYOCARDIAL INFARCTION IN THE SETTING OF ACUTE ISCHEMIC STROKE

Acute ischemic stroke is a cause of troponin elevation which is often attributed to demand, type 2 myocardial infarction (MI). The incidence of spontaneous, type 1 MI is unknown. We reviewed our prospective hospital registry of acute ischemic stroke (2009–2010). All patients had ≥3 troponin I (