AIM  To evaluate the clinical value of heparin monitoring protocol based on activated partial thromboplastin time (aPTT) in children after cavo-pulmonary connections undergoing cardiopulmonary bypass.

  METHODS  Children aged from 6 months to 6 years old who underwent bidirectional Glenn procedure or total cavo-pulmonary connection in our hospital from June 2018 to December 2019 were prospectively selected. All dose adjustments of unfractionated heparin were based on the heparin monitoring protocol guided by aPTT. According to whether the therapeutic anticoagulation could be achieved within 48 hours and the aPTT could always be maintained within the target range, the selected children were categorized into two groups: up-to-standard group and non-up-to-standard group. Univariate analysis was used to compare the perioperative clinical data between the two groups.

  RESULTS  A total of 50 children were selected and all were included in the final statistical analysis, including 27 cases (54%) in the up-to-standard group and 23 cases (46%) in the non-up-to-standard group. The aPTT of the non-standard group was shorter than that in the standard group at 24 hours and 48 hours after the administration of heparin. When heparin had administrated for 48 hours, the level of antithrombin III was lower in the up-to-standard group (P<0.05). The chest tube output in the up-to-standard group was less than that in the non-up-to-standard group within 24 hours (P <0.01) and 48 hours after surgery (P = 0.014). Moreover, the total amount of fresh frozen plasma transfusion within 48 hours in the up-to-standard group was less than that in the non-up-to-standard group (P <0.01). However, there was no statistically significant difference in the heparin maintenance dose between the two groups. In addition, the duration of mechanical ventilation and the ICU stay time in the up-to-standard group were shorter than those in the non-up-to-standard group.

  CONCLUSION  The protocol of activated partial thromboplastin time-based unfractionated heparin monitoring proposed in this study may improve the clinical outcomes in children after cavo-pulmonary connections undergoing cardiopulmonary bypass.