Risk Factors for Intraoperative Hypothermia during Holmium Laser Enucleation of the Prostate.

INTRODUCTION: Holmium laser enucleation of the prostate (HoLEP) is considered a size-independent gold standard for benign prostatic hyperplasia (BPH), and there is no upper limit of prostate weight that can be treated. Tissue retrieval can be time-consuming in cases of significant prostatic enlargement, which may lead to intraoperative hypothermia. As there are few studies on perioperative hypothermia in HoLEP, we conducted a retrospective study of patients who underwent HoLEP at our hospital. METHODS: The data of 147 patients who underwent HoLEP at our hospital were retrospectively collected and analyzed for the occurrence of intraoperative hypothermia (temperature <36°C); age, body mass index (BMI), anesthesia method, body temperature, total fluid infusion, operation time, and irrigation fluid were the explanatory variables. RESULTS: Intraoperative hypothermia was observed in 46 of 147 patients (31.3%). Simple logistic regression analysis showed that age (odds ratio [OR]: 1.07, 95% confidence interval [CI]: 1.01-1.13, p = 0.021), BMI (OR: 0.84, 95% CI: 0.72-0.96, p = 0.017), spinal anesthesia (OR: 4.92, 95% CI: 1.86-14.99, p = 0.002), and surgical time (OR: 1.04, 95% CI: 1.01-1.06, p = 0.006) were predictors of hypothermia. The decrease in body temperature was more pronounced with longer-duration surgery and reached 0.58°C at 180 min. CONCLUSION: General anesthesia, instead of spinal anesthesia, is recommended in high-risk patients with advanced age or low BMI to avoid intraoperative hypothermia during HoLEP. Two-stage morcellation may be considered for large adenomas, when a prolonged operative time and hypothermia are anticipated.

Hemolysis Precedes Urine Color Change in Patients Undergoing Open-Heart Surgery on Cardiopulmonary Bypass.

PURPOSE: Red-colored urine often occurs in patients in the perioperative period who undergo cardiac surgery using cardiopulmonary bypass (CPB). This urine color change has been utilized for approximating hemolysis during CPB without a proven relationship for ongoing hemolysis. This case series study aimed to examine the relationship between plasma free hemoglobin (Hb) levels and quantified measures of urine color. METHODS: Ten patients were enrolled in this study. Blood and urine were collected for analyses for the following time points: before surgery, two hours after the initiation of CPB, every 30 min during CPB thereafter, and 0, 2, 4, 12, and 24 hours after the completion of CPB. We measured free Hb in plasma and urine using the azide-methemoglobin method. Photographs of urine were obtained, and the luminance of the three basic colors (red/green/blue) was analyzed by quantitative luminance contrast analysis to find a correlation for hemolysis. RESULTS: Median levels of plasma free Hb were 0.015 (0.010-0.080, n = 10) g/dL at baseline. During the CPB, increases in plasma free Hb levels were measured: median plasma free Hb levels were increased to 0.100 g/dL (0.020-0.240, p = 0.039, vs. baseline, n = 9) at two hours into CPB, median and range, respectively. In contrast, increases in urinary free Hb levels and/or urine color changes were measured only after cessation of CPB in nine patients. CONCLUSION: Urine color change or elevation of urinary free Hb levels followed the elevation of plasma free Hb levels with considerable delay.