THE American Society of Anesthesiologists has been lauded for the 1984 institution of its Closed Claims Project to identify patient safety hazards.1Although the time delay from identifying to mitigating a risk using closed claims is long, such claims are a vital source of data to improve patient safety. Hove et al.  2built upon this rich history by reviewing 24 anesthesia-related death claims filed with the Danish Patient Insurance Association from 1996 to 2004.

In reviewing this article, it is important to consider the type of information available in claims data. Liability claims data do not provide valid rates of complications or deaths from anesthesia. Studies in the United States demonstrate that only a minority, approximately one in seven people, who are harmed by mistakes will submit claims, and many who have bad outcomes without an error also submit claims.3As such, using liability claims to estimate the incidence rate of harm is likely inaccurate.

Nevertheless, these data do provide us a rich opportunity to review a sample, albeit skewed, of anesthesia-related deaths and devise strategies to reduce the risk of recurrence. We wish the authors had gone further with this investigation. In reviewing the list of events in this study, it was noteworthy that 5 of the 24 deaths (21%) were classified as airway events, although only one resulted from failure to intubate or ventilate a difficult airway case. This low frequency is in contrast to the higher percentage of difficult airway–related deaths reported by the American Society of Anesthesiologists Closed Claims in the 1990s.4This could be sampling error, or may, in fact, represent the tremendous efforts by anesthesia professional societies to develop guidelines for management of difficult airways and prevention of aspiration and for training programs to ensure that residents are competent in airway management. However, we have not applied this degree of focus in other areas.

An area ripe for improvement is the process of inserting central venous catheters (CVCs). Two of the four deaths related to CVC insertion in Hove’s study were likely due to placement of a large-bore catheter into the carotid artery. Such events can be prevented with focused efforts to reduce the risk of a carotid puncture by using ultrasound guidance, and to confirm venous access with a small catheter before placement of a large catheter. The small catheter can be attached to a transducer or a fluid-filled column to show evidence of a venous pressure tracing, or absence of pulsatile flow and confirm that the catheter is in a vein. If the transducer shows an arterial waveform or the fluid-filled column does not drop when held above the level of the heart, the catheter should be removed. The extra few minutes spent performing this check could prevent a potentially devastating or even lethal complication.

Knowledge of appropriate CVC insertion will likely not result in broad improvements in patient safety until all members of the healthcare team realize that reducing risk of harm is of paramount importance and a system is established to teach this to trainees from the start. We recently learned how far we are from such a system. After investigating a fatal event involving the removal of a CVC, we identified wide variability in how residents were trained, supervised, and deemed competent to place or remove these lines. Indeed, many residents stated they were told contradictory statements such as “never do that” by one supervisor and “always do that” by another. For insertion and removal of CVC and many other procedures, we have not adhered to safety 101: Standardize your work processes, create independent checks for key steps, and learn from your mistakes. Our current training for most procedures is still based on “see one, do one, teach one.”

An improved system would be based on knowledge, skills, and behaviors. A system to eliminate CVC-related errors could include

  • developing an international guideline, training video, and knowledge test for CVC placement;

  • creating a simulation program and developing a tool to evaluate competency for CVC placement; and

  • developing a tool to evaluate performance in the real world.

Such evaluation tools should address not only the technical work but also the teamwork involved in placing these catheters. Although these types of programs are likely beyond the resources of most single institutions, it is possible within our professional communities. Professional societies can take a lead in developing such programs.

Another preventable error illustrated by this closed claims study was the erroneous attachment of an epidural catheter to an intravenous infusion that resulted in one death. Perhaps the most trumpeted improvement in anesthesia patient safety was nearly eliminating the ability to attach nitrous oxide tanks or hoses to oxygen connectors. This was accomplished by changing the shape of the yokes; the two physically cannot be connected as long as the fittings are not altered or broken. Despite the recognition this intervention received, other examples of eliminating or preventing mistakes are exceedingly rare. After the oxygen–nitrous oxide example, we should make different size connections for epidural and intravenous tubing devices so they physically cannot fit together. Such a change will require the concerted effort of many stakeholders. In the interim, hospitals could institute a policy to make this type of mistake visible. For example, we implemented a policy requiring that all epidural catheters and epidural infusion tubing be labeled with a bright-colored sticker stating “epidural only.” Although this is less foolproof than changing the tubing connectors, the increased visibility could prevent harm.

There were three deaths that involved patients who had combined epidural and general anesthesia. This is concerning, although perhaps not surprising. When using a combined anesthetic technique and assuming that the risks from regional and general anesthesia are independent, basic probability informs us that experiencing a complication from either one is the sum of the probabilities of each technique. As such, patients who receive a combined technique may have a complication rate equal to the combined rates of regional and general anesthesia. For example, the risk of an intravascular infusion of bupivacaine is independent of the risk of the inability to intubate the trachea of the patient.

When we expose patients to the risk of two anesthetic techniques, there should be some benefit to offset that risk. Are the potential benefits of a combined technique, such as better pain control, sufficient to offset the increased risk of permanent or life-threatening neurologic injury? Who makes this decision? Are patients truly informed of this increased risk with combined techniques? While this requires further research and discussion, anesthesiologists should do their best to discuss the potential risks and benefits with patients to help ensure that they are making an informed decision.

The greatest value from the study by Hove et al.  is identifying specific hazards and helping to prioritize where to focus patient safety improvement efforts. Our patients may be better served by learning deeply from a small number of hazards than learning superficially from a large number. We need to start diving deeper in our efforts to mitigate hazards. Efforts to reduce CVC and epidural errors seem like a good starting point.

Sir Liam Donaldson, the Chief Medical Officer of the United Kingdom and the Chair of the World Alliance for Patient Safety, has challenged health care by asking, “When will we be able to broadly reduce hazards?” Sir Donaldson uses the aviation industry’s methods of handling safety hazards as a model for health care to follow. He presents an example of an imaginary “orange wire” on an airplane that is found to be frayed and is thought to be more likely a defect in the design of the wire rather than normal wear and tear. The aviation industry has a system whereby this orange wire would most likely be checked and repaired on every airplane of that model throughout the world in an expeditious fashion.5Hove et al.  have taken the first step in identifying the “orange wires” we hope we will now work toward eliminating these risks.

Quality & Safety Research Group, Baltimore, Maryland, and Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Hospital, Baltimore, Maryland.

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