Cardiopulmonary effects of bronchoalveolar lavage in critically ill patients with ventilator-associated pneumonia

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Purpose

The purpose of this study was to evaluate the cardiopulmonary effects of bronchoalveolar lavage (BAL) in critically ill patients with ventilator-associated pneumonia (vap).

Method

Ten sedated and paralyzed critically ill patients suspected of having vap and requiring invasive hemodynamic monitoring were studied. A pulmonary artery catheter with continuous SvO₂ and CO display was inserted to titrate administration of fluids and vasopressors. The FiO₂ was adjusted to 1.0, 30 min before the performance of BAL for bacteriologic diagnosis and remained at this level for 6 h after the procedure. The following parameters were determined (1) before, (2) immediately after, (3) 2 h after and (4) 6 h after the BAL: compliance, P_peak, P_plat, P_i, Rs_max, Rs_min, Δ Rs, PO₂, PCO₂, pH, SaO₂, SvO₂, AP(S/D/M), PAP(S/D/M), CVP, PCWP, CI, heart rate,PVRI, SVRI, LVSWI, RVSWI, DO₂I, VO₂I, CcO₂, CaO₂, CvO₂, C(a-v)O₂, Δ PCO₂, O₂ER, Q_s/Q_t.

The paired t-test method was used to compare the results at the four different time frames. Patients with necessary manipulation in the infusion rate of fluids-vasopressors and/or the parameters of mechanical ventilation during the 6 h period were excluded from data analysis.

Results

The results of eight patients were analyzed. Compliance showed after a nonsignificant fall from (1) to (2), an increase from (2) to (3) (P=0.038) and from (2) to (4) (P=0.017). P_plat increased slightly from (1) to (2) and decreased afterwards significantly from (2) to (4) (P=0.017). PCO₂ increased from (1) to (2) (P=0.015) and remained high afterwards with parallel drop in pH from (1) to (2) (P=0.006). The CI showed, after a fall from (1) to (3) (P=0.031), a gradual improvement. PVRI demonstrated, after a nonsignificant fall from (1) to (2), a gradual increase after (2) which was significant at (4) (P=0.026). No further significant differences were recognized in every other parameter studied.

Conclusions

BAL in our patient population was a safe procedure. It did not affect oxygenation and pulmonary shunt. Compliance and P_plat showed after a nonsignificant initial deterioration gradual improvement. The delayed fall of CI did not persist at the end of the study. The increase in PVRI needs further evaluation.