Effects of consecutive protected specimen brushing and bronchoalveolar lavage on gas exchange and hemodynamics in ventilated patients.

OBJECTIVE

To assess cardiovascular effects and the oxygenation status of mechanically ventilated patients undergoing protected specimen brushing (PSB) and bronchoalveolar lavage (BAL) under fiberoptic bronchoscopy (FOB).

DESIGN

A prospective study.

SETTING

Polyvalent intensive care unit in a university hospital.

PATIENTS

Twelve consecutive, critically ill, intubated, and mechanically ventilated patients with hemodynamic failure requiring invasive monitoring with an indwelling radial artery catheter and indwelling Swan-Ganz catheter were included in the study.

INTERVENTIONS

Hemodynamic measurements, arterial and mixed-venous blood gas analyses, and arterial blood lactate analysis were performed before and at the end of a 10-min period of mechanical ventilation with a fractional concentration of oxygen in the inspired gas (FIO2) of 1.0. The same measurements and blood samplings were repeated at the end of the PSB procedure, at the end of the BAL procedure, and 1 h after the end of the BAL. During the study period the ECG, arterial oxygen saturation (SaO2), and mixed-venous oxygen saturation (SvO2) were continuously monitored.

MAIN RESULTS

A moderate increase in both mean arterial pressure and mean pulmonary arterial pressure was observed during the FOB procedure (p < 0.05). One hour after the end of BAL, the PaO2 decreased when compared with values recorded at the beginning of the procedure with the same FIO2 (p < 0.05). An increase in intrapulmonary shunt was observed at the end of BAL (p < 0.01). A moderate increase in PaCO2 was also observed after PSB (p < 0.05) and after BAL (p < 0.01). Monitoring of SaO2 permitted us to observe a significant and sustained decrease after the end of the FOB procedure from 10 to 60 min. The decrease in SvO2 was less pronounced but reached statistical significance.

CONCLUSIONS

We conclude that PSB and BAL under FOB are well tolerated in critically ill, mechanically ventilated patients with hemodynamic disturbances requiring inotropic or vasopressor agents (or both); however, a modest impairment in arterial oxygenation was observed after the end of the FOB procedure.