Survival from melphalan overdose

Accidental iatrogenic intoxications by cytotoxic drugs: error analysis and practical preventive strategies

OBJECTIVES

Drug errors are quite common. Many of them become harmful only if they remain undetected, ultimately resulting in injury to the patient. Errors with cytotoxic drugs are especially dangerous because of the highly toxic potential of the drugs involved. For medico-legal reasons, only 1 case of accidental iatrogenic intoxication by cytotoxic drugs tends to be investigated at a time, because the focus is placed on individual responsibility rather than on system errors. The aim of our study was to investigate whether accidental iatrogenic intoxications by cytotoxic drugs are faults of either the individual or the system. The statistical analysis of distribution and quality of such errors, and the in-depth analysis of contributing factors delivered a rational basis for the development of practical preventive strategies.

METHODS

A total of 134 cases of accidental iatrogenic intoxication by a cytotoxic drug (from literature reports since 1966 identified by an electronic literature survey, as well as our own unpublished cases) underwent a systematic error analysis based on a 2-dimensional model of error generation. Incidents were classified by error characteristics and point in time of occurrence, and their distribution was statistically evaluated. The theories of error research, informatics, sensory physiology, cognitive psychology, occupational medicine and management have helped to classify and depict potential sources of error as well as reveal clues for error prevention.

RESULTS

Monocausal errors were the exception. In the majority of cases, a confluence of unfavourable circumstances either brought about the error, or prevented its timely interception. Most cases with a fatal outcome involved erroneous drug administration. Object-inherent factors were the predominant causes. A lack of expert as well as general knowledge was a contributing element. In error detection and prevention of error sequelae, supervision and back-checking are essential. Improvement of both the individual training and work environment, enhanced object identification by manufacturers and hospitals, increased redundancy, proper usage of technical aids, and restructuring of systems are the hallmarks for error prevention.

CONCLUSIONS

Errors follow general patterns even in oncology. Complex interdependencies of contributing factors are the rule. Thus, system changes of the working environment are most promising with regard to error prevention. Effective error control involves adapting a set of basic principles to the specific work environment. The work environment should allow for rectification of errors without penalty. Regular and ongoing intra-organisational error analysis needs to be an integral part of any error prevention strategy. However, it seems impossible to totally eliminate errors. Instead, if the environment guarantees timely error interception, most sequelae are avoided, and errors transform into a system-wide learning tool.

Errors involving pediatric patients receiving chemotherapy: a literature review

A review of mishaps involving pediatric patients receiving anticancer chemotherapy was undertaken in order to assist intervention. Although the case literature is too sparse to provide definite recommendations, suggestions for management are made in the event of an error with a high risk (based on the case literature) of life-threatening toxicities. It is recommended that all incidents be reported in the literature in order to provide a basis for devising standard treatment protocols. It is also suggested that studies using animal models continue to be done in order to provide more experimental data about toxicities and potentially beneficial rescue therapies.

Clinical management of cytotoxic drug overdose

In this article the pharmacological management of accidental drug overdose is discussed, with various treatments for overdose proposed, as supported by clinical facts and speculation. Current knowledge is outlined concerning dacarbazine, nitrosourea compounds, melphalan, procarbazine, cyclophosphamide, VP-16.213, l-asparaginase (colaspase), 6-mercaptopurine, mustine (nitrogen mustard), intravenous or intrathecal methotrexate (amethopterin), cytarabine (cytosine arabinoside), fluorouracil and bleomycin.