Bedside noninvasive detection of acute pulmonary embolism in critically ill surgical patients

Hypothesis: We hypothesized that late pulmonary dead space fraction (Fd(late)) would be a useful tool to screen for pulmonary embolism (PE) in a group of surgical patients, including patients who required mechanical ventilation and patients with adult respiratory distress syndrome. Design: We prospectively calculated Fd(late) in patients with suspected PE who underwent pulmonary angiography. Setting: University-based. level I trauma center. Main Outcome Measure: Ability of Fd(late) to identify patients with PE. Results: Twelve patients had 14 angiograms for suspected PE. The Fd(late) was 0.12 or above in all 5 patients who had PE; 4 required mechanical ventilation. The Fd(late) values were below 0.12 in 8 of 9 patients without PE. Four patients had adult respiratory distress syndrome.. The Fd(late) had 100% sensitivity and 89% specificity for the detection of PE. Conclusions: The Fd(late) is a valuable tool for bedside screening of PE in surgical patients. We were able to accurately detect all PEs.