Hemodynamic and pulmonary changes after drainage of significant pleural effusions in critically ill, mechanically ventilated surgical patients.

profile and included measured and calculated physiologic variables, arterial blood gas measurements, and SvO2 measurements. Ventilator settings before and after were also recorded. Results: Average initial pleural effusion drainage was 1,262 762 mL (range, 300–2,980 mL). Nine of the 22 patients had effusions drained from both the right and left chest. Blood pressure, systemic vascular resistance, PO2 ,P CO2 ,S vO2 ,F IO2, peak airway pressure, and spontaneous volume did not change significantly. Pulmonary capillary wedge pressure decreased (17.4 6.0 before, 13.6 4.4 after; p < 0.01), central venous pressure decreased (14.2 5.2 before, 11.5 4.4 after; p < 0.02), and pulmonary arteriovenous shunt decreased (26.7 15.1 before, 21.0 7.8 after; p < 0.04). Oxygen delivery increased (579.7 214.7 before, 662.8 263.3 after; p < 0.01) and oxygen consumption increased (146.3 61.6 before, 175.2 73.8 after; p < 0.01). Respiratory rate also decreased (19.4 6.5 before, 15.5 6.3 after; p < 0.05). There were no complications from the placement of the pigtail catheters. Conclusion: Drainage of pleural effusions results in increased oxygen delivery and oxygen consumption coinciding with a decrease in pulmonary capillary wedge pressure. The pulmonary arteriovenous shunt decreased, implying an increase in functional residual capacity and improved oxygenation. Further study is needed to determine whether these changes lead to an improved patient outcome (i.e., reduction in length of stay, ventilator days, or mortality).