BENEFICIAL EFFECT OF ATRIAL-NATRIURETIC-PEPTIDE ON PULMONARY GAS-EXCHANGE IN PATIENTS WITH ACUTE LUNG INJURY

Study objectives: The purpose of this sturdy was to investigate the ef fect of IV infusion of atrial natriuretic peptide (ANP) on hemodynamic s, pulmonary gas exchange, and urine volume during mechanical ventilat ion with positive end-expiratory pressure (PEEP) in patients with acut e lung injury. Design: Prospective, randomized, comparable study. Sett ing: ICU of a university hospital. Patients: Forty patients with moder ate acute lung injury (lung injury score greater than or equal to 2.0) who required mechanical ventilation with PEEP were studied. Intervent ions: The patients were randomly divided into two groups: ANP group (n =20) and control group (n=20). The ANP group received genetic recombin ation alpha-human ANP (carperitide) at the rate of 0.1 mu g/kg/min for 24 h. The control group did not receive ANP. Measurements and results : Hemodynamic and blood gas parameters, and urine volume were measured at baseline, 3 h, and 24 h after initiating the ANP infusion. Plasma ANP concentrations markedly (p<0.01) increased from 112.0 +/- 27.0 to 1,868.3 +/- 385.3 pg/mL after 24 h in the ANP group, whereas they rema ined unchanged in the control group. In the ANP group, hemodynamic par ameters did not change, but PaO2/FIo(2) (fraction of inspired oxygen) and thoracic compliance significantly (p<0.01) increased at 24 h after initiating the ANP infusion, associated with significant (p<0.01) dec reases in lung injury score and shunt. Urine volume significantly (p<0 .01) increased during 0 to 3 h after initiating the ANP infusion. In t he control group, hemodynamics, pulmonary gas exchange, and urine volu me did not significantly change during the study period. There were si gnificant differences in PaO2/FIo(2) (24 h), thoracic compliance (24 h ), lung injury score (24 h), and urine volume (3 h) between the two gr oups. Conclusion: The results suggest that ANP infusion induces diures is and improves pulmonary gas exchange in patients with acute lung inj ury during mechanical ventilation with PEEP.