Abstract
Tolazoline(TOL) has been used frequently to treat pulmonary (pulm) hypertension in newborn infants with conflicting results. Eight newborn goats(age 3-17 days) were anesthetized, intubated, and ventilated. The ductus arteriosus was ligated and direct measurements were made of pulm blood flow(Qp), pulm arterial pressure(PAP), left atrial pressure and systemic arterial pressure (SAP). Moderate Hyp (PaO2 31±1.4 mmHg) caused the following changes: ↓ systemic resistance(Rs), ↑PAP, ↑ pulm resistance(Rp), ↑Rp/Rs. Qp did not change. TOL was given as a bolus (lmg/kg) and as an infusion(inf) (2 mg/kg/hr) into the pulm artery(PA) during both Hyp and after return to normoxemia(Norm). Significant pressure changes are outlined below. Values are mean ± SEM.
During Hyp, TOL bolus ↓Rp from 3.3±.53 to 2.0±.25 mmHg/L/min/kg (p<.005) and ↓Rp/Rs from .35±.03 to .27±.02(p<.001). During Norm, no significant resistance changes occurred with TOL bolus. TOL inf produced no significant changes during either Hyp or Norm.Qp did not change significantly during the experimental periods,but with severe Hyp, cardiac output and SAP fell so severely that minor changes in resistance caused by TOL could not be evaluated. These data suggest that TOL is an effective pulmonary vasodilator during moderate Hyp when injected as a bolus into the PA.
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Nestrud, R., Fewell, J., Arrington, R. et al. 1216 EFFICACY OF TOLAZOLINE HC1 AS A PULMONARY VASODILATOR IN NEWBORN HYPOXEMIC(Hyp) GOATS. Pediatr Res 12 (Suppl 4), 566 (1978). https://doi.org/10.1203/00006450-197804001-01222
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DOI: https://doi.org/10.1203/00006450-197804001-01222
