Kidney's nightshift, kidney's nightmare? Comparison of daylight and nighttime kidney transplantation: impact on complications and graft survival.

BACKGROUND: Organ distribution and internal procedures often delay kidney transplantation into nighttime. Consequently, surgeons start the operation at a time different from normal working hours, and nighttime work is accompanied by higher incidence of complications. Surgical complications in kidney transplantation often require reoperation, and graft survival can be affected. The aim of our study was to evaluate the impact of the time starting transplantation had on complications and graft survival. METHODS: Between 1994 and 2004, a total of 260 patients underwent kidney transplantation. Of these, 166 of 260 (64%) operations were initiated between 8 a.m. and 8 p.m. (day-kidney) and 94 of 260 operations (36%) between 8 p.m. and 8 a.m. (night-kidney). Mean follow-up was 43 months (range, 0-121 months). RESULTS: Overall graft failure rate was 8.1% 12 months and 12.7% 60 months after engraftment, respectively. Nighttime operation was associated with a higher risk of graft failure. Twenty-four of 260 patients (9.1%) underwent reoperation within 30 days after transplantation. Reoperation rates (night-kidney: 16 of 94 patients [16.8%], day-kidney: 8 of 166 patients [6.4%]) differed significantly between both groups. Reoperation was associated with risk of graft failure (P < .05, Cox proportional hazard). CONCLUSIONS: Nighttime surgery enhances the risk for complications and graft failure. Delaying kidney transplantation of a night-kidney to the following day may be worthwhile, even risking prolonged cold ischemia time.

Temperature response following nontraumatic low power radiofrequency application.

A marker for the efficiency of heating would be helpful in radiofrequency ablation of tachyarrhythmias. We hypothesized that changes of the catheter tip temperature during nontraumatic, very low power radiofrequency exposure would correlate with the temperature achieved during radiofrequency ablation, and therefore, could be used as a marker for heating efficiency. In 71 ablation attempts for drug refractory supraventricular tachycardias, the catheter tip temperature response to a 1-W-5-second test pulse was measured. Subsequently at the same site, radiofrequency current was delivered with a target temperature of 70 degrees C and a power limit of 50 W. The test pulse, with a measured power level of 1.62 +/- 0.28 W, resulted in a heating efficiency of 0.78 +/- 0.60 degree C/W. During ablation, the achieved tip temperature was 52.9 +/- 7.5 degrees C, requiring a power output of 40.7 +/- 10.9 W. The heating efficiency was 0.57 +/- 0.74 degree C/W. The correlation between heating efficiency at low power and during radiofrequency ablation was linear with a correlation coefficient of 0.88. Regression analysis demonstrated that a heating efficiency above 1 degree C/W predicts a mean ablation temperature above 50 degrees C with more than 95% confidence interval. The temperature response to a very low power radiofrequency application correlates with the temperature rise achieved during radiofrequency ablation. It is suggested that delivery of low power radiofrequency current could be used to determine and monitor efficiency of heating during catheter mapping and ablation procedures.