Dopamine and intraocular pressure in critically ill patients

Background: A recently released dopamine-1 receptor agonist, fenoldopam, in creases intraocular pressure (IOP) in both healthy volunteers and patients with chronic ocular hypertension. Dopamine, a potent agonist at both dopami ne-1 and -2 receptors, is frequently infused in critically hi patients for its inotropic, renal vasodilatory, and natriuretic effects. The authors hyp othesized that low doses of dopamine would significantly increase IOP. Methods: Patients in the intensive care unit who were currently receiving d opamine infusions of less than 5 mug.kg(-1).min(-1) were studied After loca l ocular anesthesia was obtained, baseline IOP was measured in each eye wit h a hand-held tonometer. IOP was then determined after dopamine was discont inued. Results: Twenty-three patients received a mean dopamine infusion of 2.6 +/- 0.2 mug.kg(-1).min(-1). Twelve of the 23 patients were receiving mechanica l ventilation during the study. Mean IOPs in nonventilated patients (n = 11 ) off dopamine were 13.1 +/- 0.9 mmHg (left eye) and 12.6 +/- 0.9 mmHg (rig ht eye). Mean IOPs for the same patients receiving dopamine were significan tly higher at 16.1 +/- 0.9 mmHg (left eye) and 15.9 +/- 1.1 mmHg (right eye ). Mean IOPs in intubated patients (n = 12) off dopamine were 12.3 +/- 0.7 mmHg (left eye) and 12.5 +/- 1.2 mmHg (right eye). Mean IOPs for the same p atients while receiving dopamine were significantly higher in intubated pat ients at 17.8 +/- 1.3 mmHg (left eye) and 17.3 +/- 1.3 mmHg (right eye). Th e average mean elevation in IOP in patients while receiving dopamine was si gnificantly higher in intubated patients as compared with nonintubated pati ents (5.2 +/- 0.9 mmHg vs. 3.1 +/- 0.6 mmHg). Conclusions Commonly used doses of dopamine are associated with increased I OP in critically ill patients. Although normal patients should be able to t olerate this elevation safely for several weeks, there may be a potential r isk in patients with preexisting glaucomatous nerve damage or ocular hypert ension, especially if they are sedated and mechanically ventilated.