Milrinone for treatment of elevated lactate in the pre-operative newborn with hypoplastic left heart syndrome

Cardiol Young. 2023 Sep;33(9):1691-1699. doi: 10.1017/S1047951122003171. Epub 2022 Oct 3.

Abstract

Background: There is a paucity of information reported regarding the use of milrinone in patients with hypoplastic left heart syndrome prior to the Norwood procedure. At our institution, milrinone is initiated in the pre-operative setting when over-circulation and elevated serum lactate levels develop. We aimed to review the responses associated with the administration of milrinone in the pre-operative hypoplastic left heart syndrome patient. Second, we compared patients who received high- versus low-dose milrinone prior to Norwood procedure.

Methods: Single-centre retrospective study of patients diagnosed with hypoplastic left heart syndrome between January 2000 and December 2019 who underwent Norwood procedure. Patient characteristics and outcomes were compared.

Results: During the study period, 375 patients were identified; 79 (21%) received milrinone prior to the Norwood procedure with median lactate 2.55 mmol/l, and SpO2 93%. Patients who received milrinone were older at the time of Norwood procedure (6 vs. 5 days) and were more likely to be intubated and sedated. In a subset analysis stratifying patients to low- versus high-dose milrinone, median lactate decreased from time of initiation (2.39 vs 2.75 to 1.6 vs 1.8 mmol/l) at 12 hours post-initiation, respectively. Repeated measures analysis showed a significant decrease in lactate levels by 4 hours following initiation of milrinone, that persisted over time, with no significant difference in mean arterial pressure.

Conclusions: The use of milrinone in the pre-operative over-circulated hypoplastic left heart syndrome patient is well tolerated, is associated with decreased lactate levels, and was not associated with significant hypotension or worsening of excess pulmonary blood flow.

Keywords: Elevated serum lactate; Norwood procedure; hypoplastic left heart syndrome; milrinone; over-circulation.

MeSH terms

  • Humans
  • Hypoplastic Left Heart Syndrome* / diagnosis
  • Infant, Newborn
  • Lactates
  • Milrinone / therapeutic use
  • Norwood Procedures* / adverse effects
  • Retrospective Studies
  • Treatment Outcome

Substances

  • Milrinone
  • Lactates