Fatal pulmonary embolism (PE) is often missed antemortem. A clinical probability score (Wells 2001) is useful, along with the D-dimer test, in identifying which patients need further workup. However, this score was validated in relatively stable outpatients. It is not known whether this score is sensitive for PE in unstable inpatients. We used the records of patients who died from PE to determine whether the clinical probability score upon presentation would have identified them antemortem.
We reviewed the reports from all autopsies performed at the University of California, San Diego Medical Center between 1970 and 2004 to find patients who died while in the hospital and in whom PE was deemed to be a contributing cause of death. We calculated a “clinical probability score” for each case by reviewing physician, nursing, and respiratory care notes documented in the records. We calculated the frequency distribution for the scores and performed linear regression to determine whether the distribution had changed over the past three decades.
There were 270 autopsies performed in which the deaths were attributable to PE, of which 214 (79%) were available for review. There was a bimodal frequency distribution of clinical probability scores, with frequency peaks at scores of 3 and 6 (out of 13). Twenty-five percent of patients had scores of 3 or less, which could be attributed to tachycardia and/or immobility in all but 1%. There was no significant change in distribution of the scores over the course of the 35 years (r = 0.002).
Throughout the study period, fatal PE was found in two distinct populations of patients, those in whom the objective clinical likelihood score was high and those in whom the score was in the low-moderate range. In the later group, most scores reflected non-specific clinical findings.
Further studies are warranted before using the clinical probability score to distinguish patients at risk of PE-related death from those with other serious cardiopulmonary problems who do not need work-ups for PE.
Jennifer Swisher, None.