The effect of exogenous surfactant therapy on lung function following cardiopulmonary bypass.

Abstract

OBJECTIVE: Pilot study to investigate the effect of exogenous surfactant therapy on lung function following cardiopulmonary bypass (CPB). DESIGN: Prospective randomized controlled study. SETTING: Adult intensive care unit of a postgraduate cardiothoracic hospital. PATIENTS: Sixteen adult patients undergoing elective coronary artery revascularization surgery without a history of preoperative respiratory disease. INTERVENTIONS: Artificial lung-expanding compound (ALEC, Britannia Pharmaceuticals, Crawley, UK) 3.2 g, was given via a bronchoscope 60 min after bypass in eight patients. Eight control subjects received air. MAIN OUTCOME MEASUREMENTS: Lung function tests during IPPV (arterial blood gas tensions, Crs, FRC, TLco, KCO) were measured prior to CPB, before therapy, and at regular intervals up to 180 min afterwards. RESULTS: The CPB caused a significant impairment of lung function in both groups with an increase in A-a gradient (+47 +/- 11 mm Hg in the ALEC group and +44 +/- 17 mm Hg in controls) and reductions in FRC (-290 +/- 121 ml in the ALEC group and -470 +/- 132 ml in controls), TLco (-1.6 +/- 0.3 ml/min/mm Hg in the ALEC group and -2.2 +/- 0.3 ml/min/mm Hg in controls), and Crs (-10 +/- 1 ml/cm H2O in the ALEC group and -21 +/- 4 ml/cm H2O in controls). The ALEC therapy did not affect A-a gradient, FRC, and Crs compared with controls. However, TLco was significantly lower in the ALEC group following therapy (120 min after treatment -0.1 +/- 0.3 ml/min/mm Hg in ALEC group and +1.0 +/- 0.3 ml/min/mm Hg in controls). CONCLUSIONS: A single 3.2-g dose of ALEC administered as a bolus bronchoscopically does not improve lung function following CPB and may impair gas transfer.