Alleviating heat loss associated with modified ultrafiltration

Modified ultrafiltration (MUF) has been described and utilized for the removal of extracellular water in the immediate postcardiopulmonary bypass (CPB) period. This technique has been associated with improved hematological status and hemodynamic stability post cardiopulmonary bypass. Hypothermia during the MUF period has been described as a complication associated with this technique. Decreased patient temperature may be associated with increased bleeding causing an increase in time to sternal re-approximation, OR time, decreases in cardiac function, peripheral vascular perfusion, and an increase in blood product utilization. These complications may reduce some of the benefits described with the use of MUF. The purpose of this study was to evaluate the use of a heated MUF infusion line to reduce the heat loss associated with this technique in a pediatric population. After obtaining Committee for Protection of Human Subjects exemption, a retrospective review to evaluate the efficiency of the hot MUF infusion line was undertaken. Twenty patients under 10 kg who underwent MUF before the change to a heated infusion line were retrospectively identified and matched to patients undergoing MUF with a heated infusion line with regard to weight, lesion, procedure, surgical staff and technique, and disposable equipment. Groups were evaluated for temperature and hematocrit change during the MUF period, blood loss and transfusion postprotamine in the OR and 24 h, and time to sternal re-approximation postprotamine. Statistical significance was seen between the two groups in temperature (-0.24 +/- 0.72 vs. - 1.58 +/- 0.89 degrees C; p < .0001) with the HotLine group having little change post MUF. Significance was also seen in the last OR temperature recorded (37.0 +/- 1.2 vs. 36.0 +/- 1.0 degrees C; p = .01) with the HotLine group having the higher temperature. There were no significant differences in hematocrit levels at 24 hours, last in the OR, or the change after the MUF period. No significant difference was found in blood transfused postprotamine in the OR, 24-h blood transfused, 24-h chest tube loss, or sternal closure. The study suggests that the use of a heated MUF infusion line safely reduces the heat loss associated with MUF in the immediate post-operative period.