Intraoperative risk factors for acute respiratory distress syndrome in critically ill patients

Risk factors for the development of acute respiratory distress syndrome (ARDS) in the intensive care unit (ICU) include positive fluid balance, high tidal volumes (TVs), high airway pressures, and transfusion of blood products. However, research examining intraoperative factors such as fluid resuscitation, mechanical ventilation strategies, and blood administration on the postoperative development of ARDS is lacking.

We assessed patients admitted to the ICU with postoperative hypoxemic respiratory failure requiring mechanical ventilation for the development of ARDS in the first 7 postoperative days using established clinical and radiological criteria. Data on risk factors for ARDS were obtained from the electronic anesthetic and medical records. Logistic regression was used to examine the independent association between fluid resuscitation, TV per ideal body weight, and number of blood products transfused during surgery and the postoperative development of ARDS, adjusting for important clinical covariates.

Of the 89 patients with postoperative respiratory failure, 25 developed ARDS. Compared with those who received <10 mL/kg/h fluid resuscitation in the operating room, patients receiving >20 mL/kg/h fluid resuscitation had a 3.8 times higher adjusted odds of developing ARDS (P = 0.04), and those receiving 10 to 20 mL/kg/h had a 2.4 times higher adjusted odds of developing ARDS (P = 0.14). TV per ideal body weight and the number of blood units transfused were not associated with ARDS development in this study.

This cohort study provides evidence to suggest a relationship between intraoperative fluid resuscitation and the development of ARDS. Larger prospective trials are required to confirm these findings.