Pulmonary and systemic hemodynamic responses to ketamine in infants with normal and elevated pulmonary vascular resistance

Abstract

Avoidance of ketamine has been recommended in children with pulmonary hypertension or with limited right ventricular reserve, despite absence of data about the effects of ketamine on pulmonary vascular resistance (PVR) in children. Ketamine has been associated with increased PVR in studies of adults; in these studies adults were spontaneously breathing through unprotected airways, despite ketamine's known effects of ventilatory depression and partial loss of airway. The authors measured pulmonary and systemic hemodynamic responses to ketamine during spontaneous ventilation in 14 intubated infants who were receiving minimal ventilatory support with an intermittent mandatory ventilation (IMV) of 4 at an FI(O2) of 0.3-0.4. No significant changes were found in cardiac index (CI), pulmonary vascular resistance index (PVRI), or systemic vascular resistance index (SVRI) in a group of 7 infants with normal PVRI or in another group of 7 infants with preexisting increased PVRI. Results did not differ in infants receiving diazepam sedation. The authors conclude that ketamine has little effect on baseline hemodynamics in mildly sedated infants whose airway and ventilation are maintained; in particular, PVRI is little changed by ketamine administration in ventilated infants with either normal or increased baseline PVRI.