Prospective analysis of the pattern and risk for severe vital sign changes during percutaneous radiofrequency ablation of the liver under opioid analgesia

OBJECTIVE. The aims of this study were to evaluate the pattern of vital sign changes and to elucidate significant risk factors for severe cardiovascular inhibition caused by percutaneous hepatic radiofrequency ablation (RFA). SUBJECTS AND METHODS. A total of 102 patients (male-to-female ratio, 73:29; age range, 35-85 years; mean age, 58.1 years) with 119 malignant hepatic tumors were enrolled and analyzed prospectively. The patients underwent percutaneous RFA with IV infusion of opioid analgesics. Changes in blood pressure (BP) and heart rate (HR) and the occurrence of significant cardiovascular inhibition (BP or HR < 70% of baseline) were monitored during the procedure. Respiratory rate and skin body temperature were recorded before and after the procedure. RESULTS. Whereas the mean BP was elevated (36%, 43/119) or depressed (36%, 43/119) with a similar frequency, the HR was predominantly depressed (56%, 66/119) during the procedure. The BP and HR were stable in only 18% cases (21/119), respectively. The respiratory rate showed no significant change (p = 0.521) after RFA; however, body temperature decreased (p < 0.001) after RFA. Although significant cardiovascular inhibition occurred in 41 cases (35%), all of the cases could be managed successfully and the technical success rate was 100% (119/119). Among the risk factors analyzed, old age (B = -0.003, p = 0.019) was significant for systolic BP depression, and contact of the RFA zone with the central portal vein (B = -0.096, p = 0.014) and female sex (B = -0.078, p = 0.033) were significant risk factors for HR depression as determined by multivariate analysis. CONCLUSION. Changes in BP and HR, especially bradycardia, are common during percutaneous RFA of hepatic lesions. Significant risk factors for severe cardiovascular inhibition include contact of the RFA zone with the branches of the central portal vein, old age, and female sex.