Is Postoperative Hyperlactatemia Following Repair of Ebstein Anomaly Associated with Adverse Outcomes?

Background: Hyperlactatemia has been associated with adverse outcomes following congenital cardiac surgery. However, we have anecdotally noted significant hyperlactatemia and vasopressor requirements following Ebstein repair despite good clinical outcomes. We sought to characterize postoperative lactate trends as well as vasopressor requirements and assess for any associations with clinical outcomes following Ebstein repair.

Methods: We retrospectively reviewed the post-operative course of children ( <18 years old) who underwent complete Ebstein repair (Cone Reconstruction) at our institution from 6/1/2018-12/31/2019. Standard demographics, operative variables, lactate values, vasopressor requirements, and echocardiographic data were collected. Lactate values and vasopressor requirements for the first 24hrs following surgery were analyzed along with the patients’ post-operative course including ventilator hours, post-operative echocardiogram results, and ICU/hospital length of stay.

Results: During the study period, 32 patients underwent complete repair for Ebstein anomaly (average age 7 ±5 years, 50% were male). Pre-operatively, 56% (n=18) had moderate or more right ventricular dysfunction and 84% had severe tricuspid regurgitation. All patients underwent a cone reconstruction and seven patients required a bidirectional cavopulmonary anastomosis to offload the right heart. Lactate levels peaked within 8 hours of ICU arrival with a peak lactate level of 5.5 ±2.5 (range 2 to 10.5). 22% of patients (n=7) had a peak lactate of 3 or less. All patients were maintained on epinephrine and milrinone through the first post-operative night, with discontinuation of vasopressors within 48 hours for 81% of patients. Extubation occurred within 4 hours of ICU arrival in 50% of patients. There were no re-intubations or deaths. Average ICU length of stay was 2.6 ± 2.2 days and hospital stay 5.3 ± 2 days. At dismissal, 100% of patients had reduced TR with trivial in 38% (n=12), mild in 38% (n=12), mild/moderate in 16% (n=5), and moderate in 9% (n=3). There was moderate or more right ventricular dysfunction in 75% (n=24) of patients at discharge. 6% (n=2) of patients had tricuspid stenosis at discharge.

Conclusion: Rising lactates and vasopressor requirements during the first 8 hours post-operatively were common after cone reconstruction for Ebstein anomaly. However, hyperlactatemia and vasopressor requirement were not associated with clinical decompensation, adverse events, or poor surgical results, and did not preclude successful extubation with rapid ICU liberation.