Clinical and autopsy diagnoses in the intensive care unit: a prospective study

Autopsy rates have declined worldwide, but recent retrospective intensive care unit (ICU) data indicate major discrepancies between more than 25% of clinical and autopsy diagnoses.

We conducted a 3-year prospective study of all consecutive autopsies performed on patients who died in a university hospital medical-surgical ICU to determine how many might have benefited from a different level of care, had the autopsy diagnosis been made before death. All clinical diagnoses were compared with autopsy findings at monthly clinical-pathological meetings. Major and minor diagnostic discrepancies were categorized according to the criteria of Goldman et al.

Of 1492 patients admitted to the ICU, 315 died, of whom 167 (53.0%) were autopsied. The most common reason (79.7%) for not obtaining an autopsy was family refusal. The mean +/- SD clinical characteristics were similar for autopsied vs nonautopsied patients, except for shorter length of ICU stay (13 +/- 17 vs 20 +/- 27 days, P =.006), shorter duration of mechanical ventilation (13 +/- 16 vs 19 +/- 25 days, P =.01), and lower percentage of postcardiac surgery patients (38.9% vs 50.0%, P =.05). Among the intensivists' 694 clinical diagnoses, 33 (4.8%) were refuted and 13 (1.9%) were judged incomplete by autopsy findings. Autopsies revealed 171 missed diagnoses, including 21 cancers, 12 strokes, 11 myocardial infarctions, 10 pulmonary emboli, and 9 endocarditis, among others. Major diagnostic errors (class I and class II discrepancies) were made in 53 (31.7%) of 167 patients, with a high percentage of immunocompromised patients also observed among these. Similar percentages of patients with class I and class II errors vs other patients had undergone modern diagnostic techniques during their ICU stay.

Even in the era of modern diagnostic technology, regular comparisons of clinical and autopsy diagnoses provide pertinent information that might improve future management of ICU patients.