effect of low dose dopamine on intraocular pressure

ABSTRACT

Fifty patients with postoperative impaired renal function evidenced by resistant oliguria were included in the study. All patients received dopamine infusion less than 5 micro.kg[-1] .min[-1]. After instilling benoxinate hydrochloride [Novesin 0.4%] eye drops, the Perkins tonometer was used to measure the intraocular pressure [IOP]. Patients were divided into two groups according to their ventilation. Group I non-mechanically ventilated patients, and group II mechanically ventilated patients. Twelve patients were excluded from the study, nine in group I and three in group II, due to stoppage of dopamine infusion, change-in the ventilatory status or due to the use of mannitol infusion. The two groups were comparable as regards age, weight and dopamine infusion dose. In the non-ventilated group, there was an insignificant difference as regards changes in the heart rate, mean arterial blood pressure [MABP], central venous pressure [CVP] and degree of sedation compared with control values at any time of measurement. A significant increase in IOP during dopamine infusion in both eyes compared with control values was detected [P<0.001]. In the ventilated group, there was an insignificant difference as regards changes in the heart rate, MABP, CVP, PaCO[2], positive end expiratory pressure [PEEP] and degree of sedation compared with control values at any time of measurement. However, there was a significant increase in IOP during the period of dopamine infusion in both eyes compared with control values [P<0.001]. The increase in IOP during the period of dopamine infusion was significantly higher in the ventilated compared to the non-ventilated group [P< 0.001]. The infusion of low dose of dopamine was associated with a significant increase in IOP in both eyes whether the patients were mechanically ventilated or not. Yet, the increase in IOP was greater in the mechanically ventilated group. Dopamine infusion should be cautiously given in patients with preexisting ocular hypertension or with traumatic eye injury. Monitoring of IOP during dopamine infusion is recommended in those patients especially during mechanical ventilation