Prediction of posttraumatic adult respiratory distress syndrome by albumin excretion rate eight hours after admission

Background: Adult respiratory distress syndrome (ARDS) in trauma victims carries a mortality on the order of 50%. An early feature is an increased capillary permeability causing an extravasation of plasma proteins and water, leading to interstitial edema. In the kidney, the increase in microvascular permeability is manifested as increased albumin excretion detectable by sensitive immunoassay. Methods: Forty seven trauma victims were studied for 5 days; 32 of them had Injury Severity Scores > 18. A diagnosis of ARDS was made on the recommendations of the American-European Consensus Conference on ARDS (1994). Eight patients developed ARDS, five developed pulmonary dysfunction, and the remainder showed no significant pulmonary abnormality. Results: Using the near patient urine albumin immunoassay, albumin excretion rate (AER) was measured after admission. For patients with Injury Severity Score > 18, the median (95% confidence interval) AER 8 hours after admission was 63 (range, 40-99) mu g per minute for those without impaired lung function and 339 (range, 162-354) mu g per minute for those in the combined ARDS and pulmonary dysfunction group (Mann-Whitney test, p = 0.0004). The median AER was 51 (range, 27-98) mu g per minute for patients with Injury Severity Score < 18. The positive predictive value for the development of ARDS or pulmonary dysfunction of AER > 130 E mu g per minute was 85%, with a negative predictive value of 95%. Conclusions: These data indicate that the capillary leak associated with the subsequent development of pulmonary dysfunction and ARDS can be detected within 8 hours of admission at the patient's bedside, thus providing a means of early identification of patients at greatest risk and allowing for early intervention.