To the Editor:—
Having read the editorial views expressed by Heitmiller, Martinez, and Pronovost,1I commend the goal of implementing procedures to improve patient safety in the practice of anesthesia. Certainly, changes in teaching practices and techniques that allow safer placement and management of central venous access catheters offer significant opportunities to have a profound impact on serious morbidity and mortality. Changes to connection ports for epidural and intravenous lines to make infusion of unintended substances more difficult also has some potential to decrease risk, although likely on a much smaller and less cost-effective scale when the relatively low incidence of misconnects is taken into account. Clear and better labeling of epidural catheters may provide nearly equal risk reduction at a lower cost. Further study may help to elucidate the ideal solution.
I do have concern, however, about the authors' remarks in relation to three deaths in patients receiving combined general–epidural analgesia, specifically regarding the authors' comment, “This is concerning, although perhaps not surprising,” going on to imply that mortality among other complications may be additive by combining the total risk of the two techniques performed independently. Although it may be true that neurologic injury, failure to intubate, or infusion of an incorrect substance are all independent risk factors, there is no suggestion in the vast amount of literature published that indicates regional anesthetic techniques either alone or combined with general anesthesia increase mortality or major morbidity. Previous studies,2which demonstrated reduction in mortality with epidural analgesia, may simply have reflected trials conducted before the introduction of routine venous thromboembolism prophylaxis and before changes in the management of patients with coronary artery disease (including perioperative β-blockers). Some recent large trials on high-risk patients with appropriate conventional perioperative management in both groups do not show a decrease in mortality and major morbidity with the addition of epidural analgesia, but also show no increase in mortality or major morbidity with the combined approach.3,4In large studies using the Medicare database, the use of combined general–epidural anesthesia has been associated with a reduction in mortality.5,6Therefore, the authors' suggestion that mortality may be increased by combining epidural with general anesthesia is contrary to the vast body of scientific research.
Neurologic injury, as the authors note, is an independent risk of epidural analgesia, and patients should be given a reasonable informed consent regarding common as well as potentially serious risks of any procedure including the risk of nerve damage from surgical causes, tourniquet, positioning, and stretch, among many other causes. There is unfortunately little consensus on what constitutes appropriate consent, because it is virtually impossible to list every possible complication. Do we go so far as to specify the estimated potential of rare but serious complications such as epidural hematoma (1:150,000),7,8abscess (>1:100,000),9–11permanent neuropathy (2.19:10,000),12and paraplegia (1:100,000),12or is it reasonable to generalize with statements such as “serious events can occur, not limited to death, heart and lung problems, aspiration, allergic reaction, nerve damage, and others”? Do we quote the overall probability of postdural puncture headache or adjust for whether a first-year resident is doing the procedure versus a highly skilled practitioner or perhaps offer no estimate of the incidence? Are we equally remiss in offering true informed consent if we do not offer patients the 30–40% reduction in pain conferred by epidural analgesia,13the improvements in patient satisfaction that are consistently noted and potentially decreased mortality?5,6Pain is witnessed on a daily basis and is of significant concern to patients. Serious neurologic injury secondary to epidural analgesia at the estimated rates may not be witnessed by many practitioners in the course of their career. Placement of epidural catheters by anesthesiologist who are not proficient in the technique and the lack of appropriate systems for postoperative management could potentially not only increase risk of serious complication but also greatly reduce any analgesic benefit and would not be recommended.
Despite disagreement with the authors' comment on the risk of mortality with combined epidural–general anesthesia and the sense that there may be an unjustified bias toward avoiding this practice, I commend the group for bringing to the forefront the importance of improving patient safety. I fully respect the outstanding work these individuals have done to implement strategies that have improved patient safety and their continuing efforts to find new areas for improvement in patient safety.
The Johns Hopkins University, Baltimore, Maryland. jrichma1@jhmi.edu
