| Abstract
| - Several efforts have been made to improve the technique ofcardiopulmonary bypass (CPB), including the use of pulsatile flow and themodification of cannulation technique. The present study focused uponextravascular lung water (EVLW) in 60 aortocoronary bypass patientssubjected to four different perfusion techniques during CPB: group 1 (n =15): non-pulsatile flow and standard cannulation; group 2 (n = 15);pulsatile flow and standard cannulation; group 3 (n = 15): nonpulsatileflow and monoatrial cannulation (i.e., always "partial" bypass during CPB);group 4 (n = 15): pulsatile flow and monoatrial cannulation. EVLW contentwas measured using the double-indicator dilution technique with indocyaninegreen; in addition, various hemodynamic and laboratory variables weremeasured. Lung water content rose above normal values (mean: 5.79 +/- 0.33ml/kg) only in the groups submitted to the standard cannulation technique,irrespective of whether the perfusion flow was pulsatile or not (group 1: +27.4%; group 2: + 25.5%). Pulmonary gas exchange, too, was compromised onlyin these patients (PaO2 in group 1 -19% and in group 2 -17%; Qs/Qt in group1 + 36 rel. % and in group 2 + 29 rel. %), whereas all patients withmonoatrial cannulation and partial bypass throughout the CPB period showedno rise in EVLW content or Qs/Qt and no drop in PaO2. From the results ofthis study we conclude that pulsatile perfusion during open heart surgicalprocedure has no advantages in regard to lung water content. Monoatrialcannulation with partial bypass at all times during CPB, however, seems tobe beneficial, probably owing to the maintenance of pulmonary circulationduring the bypass period.
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