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The hemodynamic effects of phenoxybenzamine in neonates, infants, and children

Emad Mossad1, Pablo Motta, Kulwinder Sehmbey

  • 1Department of Pediatric Anesthesia, Cleveland Clinic Foundation, Cleveland, OH 44195, USA. mossade@ccf.org

Journal of Clinical Anesthesia
|April 16, 2008
PubMed

Insights

Phenoxybenzamine causes age-dependent hemodynamic changes in pediatric patients undergoing heart surgery. Younger infants experience greater vasodilation and narrower temperature gradients during cardiopulmonary bypass (CPB).

Area of Science:

  • Pediatric Cardiology
  • Pharmacology
  • Cardiovascular Surgery

Background:

  • Congenital heart defects often require surgical intervention with cardiopulmonary bypass (CPB).
  • Alpha-adrenergic blockers like phenoxybenzamine are used to manage hemodynamic instability.
  • The impact of phenoxybenzamine on pediatric patients, particularly across different age groups, requires detailed evaluation.

Purpose of the Study:

  • To assess the hemodynamic effects of phenoxybenzamine in pediatric patients undergoing surgical repair of congenital heart defects.
  • To compare the drug's efficacy and impact on systemic vascular resistance index (SVRI) and temperature gradients across three distinct pediatric age groups.
  • To identify age as a significant factor influencing the response to phenoxybenzamine during CPB.

Main Methods:

  • Retrospective chart review of 75 pediatric patients undergoing congenital heart defect repair on CPB.
  • Patients were categorized into three age groups: <1 month, 1-12 months, and 1-5 years.
  • Hemodynamic parameters including mean arterial pressure, CPB flow, SVRI, and temperature gradients were analyzed.

Main Results:

  • Younger infants (<1 month) exhibited significantly lower SVRI, indicating more pronounced vasodilation.
  • Temperature gradients during cooling and rewarming were narrower in the youngest age group.
  • Multivariate analysis confirmed patient age as a significant variable affecting phenoxybenzamine's hemodynamic response.

Conclusions:

  • The hemodynamic effects of phenoxybenzamine, including vasodilation and temperature regulation, are age-dependent in pediatric patients on CPB.
  • Younger infants demonstrate a more pronounced response to phenoxybenzamine, characterized by greater vasodilation and altered temperature gradients.
  • These findings highlight the importance of considering age when administering phenoxybenzamine in pediatric cardiac surgery.
Abstract

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