The Impact of Continuous Positive Airway Pressure upon Pleural Fluid Pressures during Thoracentesis.

BACKGROUND

Excessive drop of pleural pressure (Ppl) during therapeutic thoracentesis may be related to adverse events and/or to repeated procedures due to incomplete drainage.

OBJECTIVE

This was a pilot study of the impact of the application of continuous positive airway pressure (CPAP) at +5 cm H2O upon the Ppl profile during thoracentesis.

METHODS

This was a prospective, controlled study of 49 consecutive adults who underwent thoracentesis. Enrollment was via alternation on a one-to-one basis. Pleural manometry was used to compare serial Ppl in patients using CPAP at +5 cm H2O (CPAP group) with Ppl in patients without CPAP (control group).

RESULTS

Mean volumes drained were comparable between CPAP and control groups (1,380 vs. 1,396 mL). Patients in the CPAP group had a significantly greater change in volume per centimeter water column pressure (p = 0.0231, 95% confidence interval 6.41-82.61). No patient in the CPAP group had a Ppl less than -20 cm H2O at termination of the procedure, while 8 (33%) control group patients developed a pressure lower than -20. No patient in either group developed re-expansion pulmonary edema.

CONCLUSION

The application of CPAP at +5 cm H2O mitigates the decreases in Ppl caused by thoracentesis via an increase in pleural compliance. The clinical implications of this finding merit study.