CARDIOPULMONARY EFFECTS OF BRONCHOALVEOLAR LAVAGE IN CRITICALLY ILL PATIENTS

Bronchoalveolar lavage (BAL) has been proposed as a useful procedure f or bacteriologic diagnosis of lower respiratory tract infection in mec hanically ventilated patients. To determine the cardiopulmonary effect s of this procedure and to identify the patients at risk of poor toler ance, 30 critically ill ventilated patients suspected of having pneumo nia were studied. Hemodynamic and gas exchange parameters were continu ously recorded using an arterial catheter, a Swan-Ganz catheter with S vO2 display, and a pulse oximeter. In addition to the basal sedation r equired by these patients, midazolam, 0.1 mg/kg intravenously, was adm inistered 5 min prior to bronchoscopy. A moderate increase (10 percent from basal values) in heart rate, mean arterial pressure, and cardiac index was recorded at each measurement during the procedure. A marked decrease in PaO2 was observed during bronchoscopy associated with an increase in oxygen consumption. Maximal changes in SaO2 and SvO2 were recorded at the end of BAL. Two hours after the end of BAL, PaO2 value s were still 20 percent lower than pre-BAL values in 40 percent of the patients. We conclude that BAL can be performed safely in most critic ally ill ventilated patients who have stable, hemodynamic and ventilat ory parameters. However, none of the recorded parameters allows identi fication of the patients at risk of poor tolerance of the procedure.