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BMJ Case Reports 2009; doi:10.1136/bcr.02.2009.1558
  • Learning from errors

Side effects of evidence-based medicine

  1. Antoine Fremault1,
  2. Daniel Rodenstein2
  1. 1
    Clinique Saint-Joseph, Pneumology, Rue de la Duchere 6, Gilly, 6060, Belgium
  2. 2
    Cliniques universitaires Saint-Luc, Av. Hippocrate 10, Brussels, 1200, Belgium
  1. Daniel Rodenstein, daniel.rodenstein{at}uclouvain.be
  • Published 14 July 2009

Summary

In the framework of an objective assessment of medical practices, it has become the rule to limit preoperative examinations, including thoracic imaging, in asymptomatic patients with a low surgical risk (that is, in “good health”). The insistence on the avoidance of “unnecessary” technical examinations in patients in seemingly good health may disregard common symptoms and lead to untoward consequences for the patients as we recently experienced in our respiratory department: two patients were admitted, one for a cavitary tuberculosis and the other one for a small cell carcinoma. These patients had uneventfully undergone in the recent weeks ear, nose and throat procedures and gynaecologic surgical procedures, respectively, without preoperative chest radiography as they were considered “asymptomatic” at the time of surgery. Retrospectively, ordinary symptoms (cough in the patient with cavitary tuberculosis and shortness of breath in the patient with lung carcinoma) were present but did not “ring a bell” during the preoperative assessment.

BACKGROUND

The literature recommends a restrictive preoperative attitude based on a standardised questionnaire and a standard physical examination. This line of reasoning centres on the preoperative surgical risks, the patient’s co-morbidities, the type of anaesthesia chosen and the particular surgical technique to be performed: it is the peri-operative period what matters more than the patient himself. Moreover, the preoperative assessment is usually performed by an anaesthetist not by the patient’s physician. Two clinical cases demonstrate the seemingly justification of such a restrictive attitude from the anaesthetic and surgical points of view. However, further evolution will show that at the time of the preoperative assessment, although no chest imaging was available or asked for, the first patient had a bronchial carcinoma whereas the second one suffered from active cavitary tuberculosis. To our knowledge, no previous study has showed this unexpected “side effect” of the new preoperative evaluation paradigm.

CASE PRESENTATION

Case 1

A 50-year-old Mulatto woman of African origin was admitted to hospital for a transhysteroscopic endometrial resection under general anaesthesia. Her antecedents were marked by a total thyroidectomy in July 2004 for a goiter, an appendicectomy and an arterial hypertension. The patient was an active smoker (20 packs/year).

A chest x ray performed 1 year ago had appeared normal. A preoperative consultation was carried out before the gynaecological intervention. The patient was found to have “chronic bronchitis” (daily coughs and expectorations in a context of active smoking). Shortness of breath during normal activities for the age was interpreted as cardiac in origin. A chest x ray was not considered to be necessary but other preoperative tests were performed: exercise test (normal), a transthoracic cardiac ultrasound (normal) and respiratory function tests (marked deterioration of the diffusion capacity). The post-operative course was uneventful.

Four months after the gynaecological intervention, a chest x ray was ordered by the general practitioner (systematic examination because the patient was working in a geriatric long-term care facility). The radiography showed a round mass of 6×5×5.5 cm near the left hilum (fig 1). The patient was then admitted to our service. She described shortness of breath for usual daily efforts (already present during the preoperative consultation). The clinical examination was unremarkable. Bronchial biopsies concluded a small cell bronchial carcinoma (a composite form is, however, not excluded on basis on the histology) limited to the thorax for which radio-chemotherapy induced a complete response. A prophylactic panencephalic radiotherapy was performed. To date, the patient is in complete remission.

Figure 1

Chest x ray obtained in case 1, 14 months after surgery.

Case 2

A 32-year-old non-smoking woman of Rumanian origin was referred to the ear, nose and throat department for a repeat endoscopy under general anaesthesia for the assessment of a chronic cough. A first endoscopy carried out by an oto-rhino-laryngologist at another institution showed an infiltration of the right arytenoid area and the posterior glottic commissure but did not permit an aetiological diagnosis. The history of the patient revealed maxillo-facial surgery (reason not specified) and a curettage under general anaesthesia. The patient was seen in preoperative consultation. No chest x ray was asked for. The patient underwent laryngeal biopsies under general anaesthesia. The biopsies showed a granulomatose lesion with caseous necrosis. Direct bacteriological examination was negative, but culture showed growth of Mycobacterium tuberculosis. Laryngeal tuberculosis was consequently diagnosed. The patient was transferred to our department. A chest x ray showed confluent micronodular opacities with several cavities in the right upper lobe and less extended lesions in the left upper lobe (fig 2). Bacteriological examinations of the expectorations were positive for auramine in direct examination and M tuberculosis was identified in the culture. The various departments where the patient had been cared for were informed of the final diagnosis. Quadri-chemotherapy (myambuthol, nicotibine, rifadine and tebrazid for 2 months’ duration) then a tri-chemotherapy (for 4 months, with the stop of the myambuthol) was started with a clear clinical and radiological improvement and with a bacteriological negativation.

Figure 2

Chest x ray obtained in case 2 at the time of admission.

DISCUSSION

Guidelines applied without caution can lead to unexpected results. We have presented two cases were the routine application of preoperative guidelines resulted in management errors, not for the surgical procedures but for the patients themselves. We believe this is not the fate of young, inexperienced or careless physicians, but is the consequence of the “guideline-oriented” attitude that evidence-based medicine (EBM) is forcing on all of us, which blurs the individual patient facing us behind the “average” patient described by the guidelines. Indeed, guidelines are an essential component of EBM and are derived from EBM. The guidelines apply to the greatest number, not to the exceptions, and are used to standardise the assumption of responsibilities, to avoid wasting efforts and resources, and to improve the way medicine is performed. As exemplified in our report, a young patient with a “light” medical history will be regarded as asymptomatic and in “good health” and will thus not justify the order for a preoperative thorax x ray in agreement with the guidelines.1 “Good health” means, in this context, able to support the anaesthesia and the programmed intervention and does not necessarily mean in good health in general. The guidelines reassure the doctor and, we think, may anaesthetise his perspicacity. Uneventful surgery will seemingly confirm that everything went well and was done as it should have been done. Complications will occur later at a time the intervening anaesthetist and surgeon will no longer be in charge of the patient. They may well never learn that something had gone wrong at the time they were in charge. To our knowledge, there is no study interested in this type of unexpected unfavourable effect that only becomes apparent after the postoperative period.

Although guidelines are intended to benefit populations of patients, the clinician who applies them should consider whether the circumstances of the individual patient he is facing correspond to the “average” patient depicted in the guidelines. If the answer is “not”, or even “not fully”, it might be wise to deviate from the guidelines recommendations. It would not be impossible that the incidence of this type of event is raised, as suggested by Mendelson et al2 who found that in approximately 9% of patients the preoperative chest radiography had significant impact on postoperative management.

LEARNING POINTS

  • Guidelines describe the average patient not necessarily the patient actually facing the physician.

  • “Good health” in preoperative consultation means able to support the anaesthesia and the programmed intervention and does not mean good health.

  • Guidelines applied without discernment can lead to unexpected “side effects”.

Footnotes

  • Competing interests: none.

  • Patient consent: Patient/guardian consent was obtained for publication.

REFERENCES

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