In a controlled study of newborns with refractory low-output states (n = 16), a bolus dose of enoximone, 1 mg kg-1min-1, produced a dramatic haemodynamic improvement in 12 of 16 patients ('responders'). Of these 12, 9 survived. All 'non-responders' died subsequently. Enoximone resulted in reduced filling pressures (P < 0.005) and improved cardiac index (before enoximone, 0.96 litres min-1 m-2; after enoximone, 3.05 litres min-1 m-2; P < 0.001). To assess the routine use of enoximone in paediatric surgical patients, enoximone was administered post-operatively in 84 children in addition to standard therapy during 1991-92. Clinical improvement was noted in 58 of 84 patients (69%) and no significant side-effects were observed. It is concluded that enoximone provides a safe and effective pharmacological approach for the management of cardiac low-output states in children.