Original Contributions
Detection of fluid volume absorption by end-tidal alcohol monitoring in patients undergoing endoscopic renal pelvic surgery

https://doi.org/10.1016/S0952-8180(99)00077-XGet rights and content

Abstract

Study Objective: To determine the risk of relevant fluid absorption (calculated volume above 500 ml) during endoscopic procedures of the renal pelvis.

Design: Prospective clinical investigation with implementation of statistical process control tools (SPC).

Setting: Nonuniversity teaching hospital.

Patients: 62 consecutive ASA physical status I and II patients scheduled for endoscopic renal pelvic surgery with general anesthesia.

Interventions: Intraoperative measurement of breath alcohol for detection of fluid absorption. Irrigation fluid (0.9% saline) with 1% alcohol for tracing the irrigation fluid.

Measurements and Main Results: Calculation of the amount of fluid absorbed using breath alcohol values. Process variability (numbers of patients with relevant fluid absorption) defined by SPC. The prevalence of fluid absorption in endoscopic renal pelvic surgery was 6%. Peak fluid absorption during a vascular route was detected by the monitoring. Monitoring was easily introduced into routine clinical practice. No relevant side effects due to the monitoring were seen in patients with relevant fluid absorption. There was no mortality, but two patients with detected severe fluid overload were admitted to the intensive care unit for treatment.

Conclusion: Breath alcohol levels during general anesthesia for endoscopic renal pelvic surgery were technically simple to measure. Our results show the predictive value of alcohol monitoring, which has been previously demonstrated only for transurethral prostatectomy. The prevalence of relevant fluid absorption was 6% compared to 13% during transurethral resection of the prostate.

Introduction

Endoscopic techniques for surgical procedures are increasing steadily. At the same time, new side effects of these techniques are on the rise. Therefore, awareness of potential harm is essential in treating patients with new techniques. The fluid absorption of hypotonic irrigation solution is a well-known complication during transurethral resection of the prostate (TURP). Such a syndrome can occur during any procedure in which large amounts of irrigation fluids are used. Excessive absorption may lead to hypervolemia and life-threatening complications such as hypervolemia, electrolyte disturbances, and consequent cardiorespiratory collapse. Cardiovascular morbidity and mortality were shown to increase with fluid absorption.1 In the past, various methods such as electrolytes monitoring, monitoring of hemoglobin (Hb) concentration, or measuring the weight of the patient, as well as tracing the irrigation fluid with radioactive isotopes, were suggested as ways to detect fluid absorption.2, 3 Then, measurement of end-tidal breath alcohol levels was successfully introduced into clinical practice. Measuring end-tidal breath alcohol levels became standard in many institutions.4 This monitoring tool significantly improved the process quality, resulting in a better outcome with fewer complications after TURP.5

Endoscopic renal pelvic surgery using large amounts of irrigating fluid also may pose a high risk for fluid absorption. Therefore, we applied the monitoring with tracing the irrigation fluid with alcohol to endoscopic renal pelvic surgery. The aim of this study was to investigate consecutive patients scheduled for elective surgery on the renal pelvis (nephrolithopalaxy, endopyeloplasty) regarding practicability and clinical relevance of findings using the described monitoring.

Section snippets

Material and methods

After institutional approval from the Kantonsspital Ethics Committee, 62 consecutive patients scheduled for endoscopic renal pelvic surgery were investigated. This study was a part of a quality control program with special focus on process quality improvement using an interdisciplinary approach. General anesthesia was chosen in all patients because of patient positioning (prone) and the need for repeated tilt maneuvers. After oral premedication with midazolam (7.5 mg), anesthesia was induced

Results

Demographic data are summarized in Table 1.

In this series, time to maximum fluid absorption occured after a minimum of 30 minutes. Less than 500 ml of irrigation fluid was absorbed in 94% of all cases (Figure 1). Maximal calculated fluid absorption was 2,236 ml after a duration of 30 minutes. Two patients showed a calculated fluid absorption above 1,000 ml. One of these patient showed severe clinical signs of volume overload (lung edema, myocardial ischemia) and was successfully treated in

Discussion

During any endoscopic procedure using irrigation fluids, significant fluid absorption can occur. To reduce morbidity and mortality, breath alcohol measurement has been verified to be a quality management tool for TURP.5 Recently published data and our own results also demonstrate the usefulness of this monitoring in endoscopic renal pelvic surgery.

In contrast to TURP, absorption of fluid can occur rapidly by perirenal vessels as well as more gradually by the retroperitoneal route during

Acknowledgements

For his technical assistance we would like to thank Beat Kaiser, CRNA; for his editorial support, Dr. Stefan Zbinden, Head of Department of Anesthesiology, Wolhusen and Uli Schneider, MD, Munich, for creating the database.

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