Fig. 8. Phenylephrine dose–response relation in the conscious state and during propofol anesthesia after β-adrenoreceptor block with propranolol. Increases in the pulmonary vascular pressure gradient (PAP-LAP) at left pulmonary blood flow = 80 ml · min−1· kg−1in response to the cumulative administration of phenylephrine are summarized. The magnitude of phenylephrine-induced pulmonary vasoconstriction is either preserved or potentiated (* P < 0.05) during propofol anesthesia.
