Objective: To investigate whether the adenosine-antagonist theophylline reduces the incidence of contrast-induced nephropathy (CIN).
Design and setting: Prospective, comparison to series of patients at similar risk of CIN in a university hospital medical ICU.
Patients: 78 ICU patients with at least one risk factor for CIN undergoing 150 consecutive contrast examinations.
Interventions: Administration of 200 mg theophylline/70 kg BW intravenously 30 min before that of 100 ml or more low-osmolarity contrast medium (CM).
Measurements and results: Concentrations of serum creatinine and blood urea nitrogen (BUN), urine volume, fluid balance, and the incidence of CIN [increase in creatinine > or =20.5 mg/dl (= 44.2 micromol/l) within 48 h] were monitored for 48 h. Despite the large number of risk factors (6.8 per patient) including a high dose of CM (169.4 ml), impaired renal function (51%), diabetes (38%), aminoglycosides (61%), vancomycin (53%), catecholamines (52%), creatinine concentrations were not increased 24 h (1.40+/-0.92 mg/dl) or 48 h (1.38+/-0.88 mg/dl) after CM [1.47+/-1.0 mg/dl (= 130+/-88 micromol/l)] vs. baseline. The fluid balance was not different before (+3 ml/h) and after CM (-9 ml/h). The urine volume slightly increased after CM and theophylline (184 ml/h vs. 164 ml/h). Only three patients (2%) developed CIN. The incidence was significantly lower than that of 14% (78/565) in the control series with patients at comparable risk of CIN (p < 0.0001).
Conclusions: Using a theophylline prophylaxis the incidence of CIN in patients with increased risk of CIN is as low as 2%.