EFFECT OF VENTILATION ON FIRST-PASS PULMONARY RETENTION OF ALFENTANILAND SUFENTANIL IN PATIENTS UNDERGOING CORONARY-ARTERY SURGERY

We have studied, in 14 patients undergoing elective aorto-coronary byp ass surgery, the effect of the type of ventilation on pulmonary retent ion of alfentanil and sufentanil using a double indicator technique. P atients were allocated to one of two groups to receive either bolus do ses of sufentanil 33.2 mu g (n = 6) or alfentanil 654 mu g (n = 8), mi xed with indocyanine green. In each patient, pulmonary first-pass rete ntion was studied during apnoea (during the 1-min study period), normo ventilation and positive end-expiratory pressure (10 mm Hg) ventilatio n, the order of which was randomized. After sufentanil, mean (95% conf idence interval) first-pass pulmonary retention was 50.9 (41.7-60.1)% during apnoea, 50.8 (42.9-58.8)% during normoventilation and 54.4 (43. 7-65.0)% during positive end-expiratory pressure ventilation. After al fentanil, first-pass pulmonary retention was 18.7 (5.4-32.0)% during a pnoea, 19.9 (8.3-31.5)% during normoventilation and 16.6 (5.6-27.6)% d uring positive end-expiratory pressure ventilation. First-pass pulmona ry retention of alfentanil and sufentanil was not significantly affect ed by the type of ventilation.