| dc.description.abstract | Postoperative hypertension after cardiac surgery is common and associated with substantial morbidity. Both sodium nitroprusside (SNP) and nicardipine (NIC) are effective in its management. SNP is inexpensive, but associated with labile blood pressure (BP) control, cardiac ischemia, and metabolite toxicity. NIC is well tolerated and provides stable BP control, but is limited by high acquisition cost. We conducted a cost-effectiveness analysis from an institutional perspective of NIC versus SNP in subjects experiencing postoperative hypertension after cardiac surgery. A retrospective, cohort study identified subjects who underwent coronary artery bypass grafting (CABG) and/or valve surgery at our institution between 2007-2009. We included adults experiencing postoperative hypertension requiring ≥ 30 minutes of either NIC or SNP infusions. Institutional-specific data from the Society of Thoracic Surgeons and University HealthSystem Consortium national databases and our financial and electronic medical records were used. The number of infusion rate changes divided by the infusion duration was calculated. We considered ≥ 1 dose change/hour to represent excessive dose changes and presumably uncontrolled blood pressure. The rate per 100 subjects in each group who avoided excessive dose changes served as the efficacy variable for the economic model. Direct postoperative costs were calculated. Data were compared with t, Wilcoxon Rank Sum, Chi-square, or Fisher's exact tests as appropriate. Log-binomial regression was used to control for surgery type and severity of illness. Of the 112 subjects identified, 72 received NIC and 40 SNP. Demographics including hypertension history, number of preoperative antihypertensive agents, surgery type, and postoperative length of stay were not significantly different. NIC required significantly fewer dose changes/hour (1.2±1.6) versus SNP (1.7±1.8, p=0.004). After controlling for surgery type and severity of illness, the risk of excessive dose changes was 60% higher in those subjects prescribed SNP compared to those prescribed NIC (adjusted relative risk = 1.60, 95%CI, 1.10-2.34, p=0.0147). In the entire cohort and each specific surgery type, NIC remained cost-effective when compared to SNP. NIC use may be limited due to decisions based solely upon acquisition costs. We found that NIC resulted in less frequent dose changes and was cost-effective when compared to SNP in the treatment of post-cardiac surgery hypertension. | |
