How should I wean my next intra-aortic balloon pump? Differences between progressive volume weaning and rate weaning.

Objective: Although the intra-aortic balloon pump is the most used ventricular assist device, no study has ever evaluated the best weaning method. We compared 2 different intra-aortic balloon pump weaning methods.

Methods: Thirty consecutive patients needing an intra-aortic balloon pump because of perioperative low-output cardiac syndrome were randomized to be weaned by ratio (4 consecutive hours of a 1:2 assisting ratio followed by 1 hour of a 1:3 ratio; group R) or by progressive volume deflation (10% of total volume every hour for 5 consecutive hours; 15 patients, group V). A duration of 5 hours was set a priori as the weaning duration. The weaning protocol was started when the cardiac index was greater than 2.5 L/min/m(2), the central venous pressure was 12 mm Hg or less, the blood lactate was less than 2.5 mmol/L, the mean arterial pressure was greater than 65 mm Hg, and the preserved urine output (≥1 mL/kg/hr) lasted for at least 5 consecutive hours before weaning. The cardiac index, indexed systemic vascular resistance, cardiac cycle efficiency, and central venous pressure were registered at 9 points (T0, start; T1 to T5, the first 5 weaning hours; T6, 2 hours after withdrawal; T7, 12 hours after withdrawal; and T8, at intensive care unit discharge) using the pressure recording analytical method. The interval from intra-aortic balloon pump withdrawal to intensive care unit discharge, weaning failure, perioperative troponin I, and lactate (same points) were compared.

Results: All patients, except for 1 belonging to group R (P = 1.0), were successfully weaned. Group V had better preserved cardiac index, indexed systemic vascular resistance, cardiac cycle efficiency, and central venous pressure (group*time P = .0001). Group R had worse cardiac index from T5 to T8 (P ≤ .0001), indexed systemic vascular resistance from T2 to T8 (P ≤ .004), cardiac cycle efficiency from T3 to T8 (P ≤ .001), central venous pressure from T4 to T8 (P ≤ .0001), and a longer interval from intra-aortic balloon pump withdrawal to intensive care unit discharge (P = .0001). The lactate level was lower in group V from T5 to T8 (P ≤ .027; group*time P = .001).

Conclusions: Intra-aortic balloon pump weaning by volume deflation allowed better hemodynamic and metabolic parameters.