Objective: To determine the cause of unexplained postoperative adult respiratory distress syndrome (ARDS).
Design: Case-control study of postoperative ARDS.
Setting: Intensive care unit (ICU) of a Veterans Affairs hospital.
Patients: Six postoperative patients recovering from uncomplicated vascular or cardiothoracic surgery developed unexplained ARDS. Controls were 17 patients having similar procedures without the development of ARDS.
Intervention: Infusion of fentanyl with a tamper-proof device.
Measurements and main results: Development of ARDS. ARDS began 1 to 4 days after surgery, was characterized by maximum alveolar-arterial oxygen gradient that ranged from 232 to 544 torr (30.9 to 72.5 kPa), and was associated with death of two patients. We observed no association with patient location before ARDS onset, nonanalgesic medication administered, staff assignment, or mode of respiratory therapy. All six patients who developed unexplained ARDS had received epidural fentanyl compared with none of 17 control patients without ARDS (p = .0002). We instituted a tamper-proof mode of parenteral fentanyl administration, and subsequently observed one case of ARDS in 26 consecutive surgical patients (p = .000014).
Conclusions: Based on these findings, as well as a prior history of fentanyl theft at our institution, we conclude that tampering with fentanyl infusate was responsible for the ARDS epidemic that we observed.