Bucknam McPeek

Preventable anesthesia mishaps: a study of human factors.

A modified critical-incident analysis technique was used in a retrospective examination of the characteristics of human error and equipment failure in anesthetic practice. The objective was to uncover patterns of frequently occurring incidents that are in need of careful prospective investigation. Forty-seven interviews were conducted with staff and resident anesthesiologists at one urban teaching institution, and descriptions of 359 preventable incidents were obtained. Twenty-three categories of details from these descriptions were subjected to computer-aided analysis for trends and patterns. Most of the preventable incidents involved human error (82 per cent), with breathing-circuit disconnections, inadvertent changes in gas flow, and drug-syringe errors being frequent problems. Overt equipment failures constituted only 14 per cent of the total number of preventable incidents, but equipment design was indictable in many categories of human error, as were inadequate experience and insufficient familiarity with equipment or with the specific surgical procedure. Other factors frequently associated with incidents were inadequate communication among personnel, haste or lack of precaution, and distraction. Results from multi-hospital studies based on the methodology developed could be used for more objective determination of priorities and planning of specific investments for decreasing the risk associated with anesthesia.

Reporting on Methods in Clinical Trials

Abstract A clinical trial cannot be adequately interpreted without information about the methods used in the design of the study and the analysis of the results. To determine the frequency of reporting what we consider 11 important aspects of design and analysis, we surveyed all 67 clinical trials published in the New England Journal of Medicine, the Lancet, and the British Medical Journal from July through December 1979 and in the Journal of the American Medical Association from July 1979 through June 1980. Of all 11 items in the 67 trials published in all four journals, 56 per cent were clearly reported, 10 per cent were ambiguously mentioned, and 34 per cent were not reported at all. At least 80 per cent of the 67 trials reported information about statistical analyses, statistical methods used, and random allocation of subjects, yet only 19 per cent reported the method of randomization. Loss to follow-up was discussed in 79 per cent of the articles, treatment complications in 64 per cent, and admission...

Preventable anesthesia mishaps: a study of human factors*

A modified critical-incident analysis technique was used in a retrospective examination of the characteristics of human error and equipment failure in anesthetic practice. The objective was to uncover patterns of frequently occurring incidents that are in need of careful prospective investigation. Forty seven interviews were conducted with staff and resident anesthesiologists at one urban teaching institution, and descriptions of 359 preventable incidents were obtained. Twenty three categories of details from these descriptions were subjected to computer-aided analysis for trends and patterns. Most of the preventable incidents involved human error (82%), with breathing-circuit disconnections, inadvertent changes in gas flow, and drug syringe errors being frequent problems. Overt equipment failures constituted only 14% of the total number of preventable incidents, but equipment design was indictable in many categories of human error, as were inadequate experience and insufficient familiarity with equipment or with the specific surgical procedure. Other factors frequently associated with incidents were inadequate communication among personnel, haste or lack of precaution, and distraction. Results from multi-hospital studies based on the methodology developed could be used for more objective determination of priorities and planning of specific investments for decreasing the risk associated with anesthesia.

Reporting clinical trials in general surgical journals.

Readers need information about the design and analysis of a clinical trial to evaluate and interpret its findings. We reviewed 84 therapeutic trials appearing in six general surgical journals from July 1981 through June 1982 and assessed the reporting of 11 important aspects of design and analysis. Overall, 59% of the 11 items were clearly reported, 5% were ambiguously discussed, and 36% were not reported. The frequency of reporting in general surgical journals is thus similar to the 56% found by others for four general medical journals. Reporting was best for random allocation (89%), loss to follow-up (86%), and statistical analyses (85%). Reporting was most deficient for the method used to generate the treatment assignment (27%) and for the power of the investigation to detect treatment differences (5%). We recommend that clinical journals provide a list of important items to be included in reports on clinical trials.

Randomized clinical trials in surgery.

When it is well conducted, a randomized clinical trial provides the strongest evidence available for evaluating the comparative effectiveness of the interventions tested. Over the last two generations, we have learned much about various devices for strengthening them and about methods of avoiding pitfalls in their design, execution, analysis, and reporting. In a trial, we seek evidence for a causal link between treatments and observed outcomes. Because the controlled trial depends on an argument based on exclusion (i.e., no other causes or differences affected the experimental groups), we strengthen its inference by taking steps to exclude any such differences. This article discusses a number of issues that deserve consideration: problems and generalizability, devices for strengthening trials, issues of power and sample size, the relationship between study design and reported gains, when to undertake a trial, the role of collaborative trials, and ways to make trials more feasible in clinical settings.

Use of subjective responses to evaluate efficacy of mild analgesic-sedative combinations.

Effects of mild analgesic‐sedative combinations on sleep and pain were studied in 420 hospitalized patients, most of whom were young postpartum patients with mild or moderate evening pain who expected to have difficulty sleeping. Each patient took an analgesic‐sedative or a placebo at bedtime, on a double‐blind, random basis, and evaluated its effects the following morning. Two dose levels of chloral hydrate (250 and 500 mg), each given with aspirin (650 mg), were compared with placebo and with each other. Three other analgesic‐sedative combinations, containing methapyrilene fumarate (42 or 50 mg) combined with aspirin and/or aspirin‐like analgesics, were also studied. The combinations containing methapyrilene are similar to ones sold over the counter and are not as subiect to abuse as are medications usually prescribed to induce and maintain sleep. The patients estimate of number of hours slept significantly differentiated each experimental treatment from each other treatment with which it was compared; other subiective criteria did not differentiate as successfully. The influence of question format, response options, and other such methodological details is illustrated and discussed in this report.

DEVELOPMENT OF TWO INDICES OF POSTOPERATIVE MORBIDITY

Two indices of postoperative morbidity, Nursing Assessment Index and Observed Treatment Index, are described and evaluated in this study of 4,182 consecutive anesthetics. The use of these indices in studies of the quality and effectiveness of surgical and anesthetic care should increase the economy and precision with which the causes of unsatisfactory outcome are identified. Specific illustrations of the relationship of the preanesthetic status of patients to their postoperative morbidity as measured by these indices and mortality rates are given. In addition these two indices of morbidity measured on the seventh postoperative day are shown to be strongly co-related with subsequent in-hospital deaths. Thus, of the 100 patients with a Nursing Assessment Index worse than 3, 19 percent died; only 0.4 percent of the 550 patients who had no morbidity as measured by this index died. Although they ultimately survive, about an equal number of patients become seriously ill as die follow operations.

Preventable Anesthesia Mishaps: A Study of Human Factors

A modified critical-incident analysis technique was used in a retrospective examination of the characteristics of human error and equipment failure in anesthetic practice. The objective was to uncover patterns of frequently occurring incidents that are in need of careful prospective investigation. Forty-seven interviews were conducted with staff and resident anesthesiologists at one urban teaching institution, and descriptions of 359 preventable incidents were obtained. Twenty-three categories of details from these descriptions were subjected to computer-aided analysis for trends and patterns. Most of the preventable incidents involved human error (82 per cent), with breathingcircuit disconnections, inadvertent changes in gas flow, and drugsyringe errors being frequent problems. Overt equipment failures constituted only 14 per cent of the total number of preventable incidents, but equipment design was indictable in many categories of human error, as were inadequate experience and insufficient familiarity with equipment or with the specific surgical procedure. Other factors frequently associated with incidents were inadequate communication among personnel, haste or lack of precaution, and distraction. Results from multi-hospital studies based on the methodology developed could be used for more objective determination of priorities and planning of specific investments for decreasing the risk associated with anesthesia.