Background
The routine use of protamine in cardiac surgery to neutralize heparin is usually associated with systemic reactions that result in substantial morbidity and mortality.
Aim
This study aimed to investigate the relationship between neutral protamine Hagedorn (NPH) insulin use and severe adverse reactions to intravenous protamine given after cardiopulmonary bypass.
Methods
After obtaining hospital ethics committee approval and after obtaining informed consent, 100 patients between 45 and 70 years of age of American Society of Anesthesiologist physical status II–III undergoing elective primary isolated coronary artery bypass grafting were included in this prospective study, which was conducted between May 2013 and June 2014. Patients were divided into two groups: the NPH group (50 patients), which included patients who were on NPH insulin preparation for more than 5 years before the study, and the non-NPH group (50 patients), which included patients on oral hypoglycemics. The incidence of protamine reactions was recorded for 30 min after protamine infusion. The incidence of severe hypotension, increased airway pressure, and cardiac arrest were compared using the -test. A value less than 0.05 was considered significant.
Results
All patients (50 in each group) completed the study. There was no significant difference in patients’ demographic data, preoperative comorbidities, and surgical factors between the two study groups. The number of patients who had hypotension was significantly higher in the NPH insulin group compared with the non-NPH group. For both groups, there was no significant difference with respect to bronchospasm, cardiac arrest, and increased pulmonary artery pressure.
Conclusion
This prospective study showed increased risk for hypotension among patients receiving NPH insulin for more than 5 years compared with those who were not exposed to NPH insulin.