Urine sampling can be used to estimate weight loss due to dehydration in adults up to age 70. A robust dehydration index based on four indicators reduces the influence of confounders.

The ethanol concentration in the expired breath (EB-ethanol), the volumetric fluid balance and the serum sodium concentration were measured in the course of 60 transurethral resections of the prostate in which the irrigating fluid was 1.5% glycine + 1% ethanol. Measurement of EB-ethanol indicated absorption of irrigant at a rate of more than 150 ml in 10 min, as measured volumetrically. There was a significant direct linear relationship between EB-ethanol and the cumulative volume of irrigant absorbed (R2 = 0.83); this correlation was stronger when the duration of absorption was taken into account (R2 = 0.90). EB-ethanol was inversely related to the overall change in the serum sodium concentration during the operation (R2 = 0.88). Symptoms that are recognized components of the TUR syndrome developed in 8 of the 13 patients absorbing more than 11 of irrigant, while the ethanol exerted no adverse effects. The results of the study indicate that 1% ethanol is a suitable marker for monitoring irrigant absorption by means of the expired breath test in routine transurethral surgery. At this concentration the sensitivity of the test is adequate for detecting absorption, while the ethanol is less toxic than the irrigant fluid itself.

The transurethral resection syndrome ("TUR syndrome") is caused by absorption of electrolyte-free irrigating fluid, and consists of symptoms from the circulatory and nervous systems. The clinical picture is inconsistent and the syndrome is easily confused with other acute disorders. Mild forms are common and often go undiagnosed, while severe forms of the TUR syndrome are rare and potentially life-threatening. The pathophysiology is complex but includes four mechanisms: circulatory distress from the rapid absorption of electrolyte-free irrigating fluid, adverse effects of glycine, dilution of the protein and electrolyte concentrations of the body fluids, and disturbance of renal function. The treatment of the TUR syndrome consists of general life support and in specific treatment directed towards hypotension, hyponatraemia and anuria. Methods to lower the uptake of irrigating fluid are widely used and probably reduce the incidence of the TUR syndrome. However, patient safety can be guaranteed only if the absorption is monitored. An irrigating fluid containing tracer amounts of ethanol can be used for this purpose. This permits the uptake of fluid to be indicated by measuring the concentration of ethanol in the patient's exhaled breath.

The absorption of irrigating fluid was measured by the ethanol method every 10 minutes during the course of 700 transurethral prostatic resections. The total blood loss was also measured using a photometer method. We found that ethanol determination is a convenient method of monitoring irrigating fluid absorption in daily practice. Absorption in excess of 150 ml. was detected in 46% of the operations. The volume of irrigant absorbed increased with the weight of the removed prostatic tissue, operating time and blood loss. The uptake of fluid usually started midway through the operation. Once absorption had started, there was an 87% probability that it would continue through the next 10 minutes with the exception of the last 10 minutes of surgery, when there was a 67% probability. A sudden decrease in arterial pressure coincided with the onset of fluid absorption 3.7 times more often than expected by chance. The absorption was no different in the 114 patients with a cancerous histology, compared to those with benign prostatic hyperplasia.

No abstract