Impact of Anesthetic and Ventilation Strategies on Invasive Hemodynamic Measurements in Pediatric Heart Transplant Recipients

BACKGROUND

Care of pediatric heart transplant recipients relies upon serial invasive hemodynamic evaluation, generally performed under the artificial conditions created by anesthesia and supportive ventilation.

OBJECTIVES

This study aimed to evaluate the hemodynamic impacts of different anesthetic and ventilatory strategies.

METHODS

We compared retrospectively the cardiac index, right- and left-sided filling pressures, and pulmonary and systemic vascular resistances of all clinically well and rejection-free heart transplant recipients catheterized from 2005 through 2017. Effects of spontaneous versus positive pressure ventilation and of sedation versus general anesthesia were tested with generalized linear mixed models for repeated measures using robust sandwich estimators of the covariance matrices. Least squared means showed adjusted mean outcome values, controlled for appropriate confounders.

RESULTS

720 catheterizations from 101 recipients met inclusion criteria. Adjusted cardiac index was 3.14 L/min/m² (95% CI 3.01-3.67) among spontaneously breathing and 2.71 L/min/m² (95% CI 2.56-2.86) among ventilated recipients (p < 0.0001). With spontaneous breathing, left filling pressures were lower (9.9 vs 11.0 mmHg, p = 0.030) and systemic vascular resistances were higher (24.0 vs 20.5 Woods units, p < 0.0001). After isolating sedated from anesthetized spontaneously breathing patients, the observed differences in filling pressures and resistances emerged as a function of sedation versus general anesthesia rather than of spontaneous versus positive pressure ventilation.

CONCLUSION

In pediatric heart transplant recipients, positive pressure ventilation reduces cardiac output but does not alter filling pressures or vascular resistances. Moderate sedation yields lower left filling pressures and higher systemic vascular resistances than does general anesthesia. Differences are quantitatively small.