Haemodynamics and fluid balance after intravenous infusion of 1.5% glycine in sheep.

With the aim of studying the pathophysiological background of the "TUR syndrome", we gave six conscious ewes an intravenous infusion of 57 ml/kg of 1.5% glycine solution over 40 min. Isotonic saline infusions served as controls. Central haemodynamics were monitored. The plasma concentrations of protein, K, Na and vasopressin, and plasma osmolality were measured repeatedly for up to 4 h. The urinary excretions of Na, K and osmoles were also followed. Both infusions caused an elevation of the mean arterial pressure. With glycine, the pressure increased from 93 +/- 4 to 112 +/- 12 mmHg (12.4 +/- 0.5 to 14.9 +/- 1.6 kPa) (mean +/- s.d.). The pulmonary capillary wedge pressure increased from 7 +/- 3 to 16 +/- 3 mmHg (0.9 +/- 0.4 to 2.1 +/- 0.4 kPa) and remained slightly elevated. The central venous pressure rose from 2 +/- 3 to 11 +/- 3 mmHg (0.3 +/- 0.4 to 1.5 +/- 0.4 kPa) but returned to baseline within 30 min after the infusion. Infusion of glycine resulted in a decrease in the plasma Na concentration from 144 +/- 3 to 114 +/- 4 mmol/l. The plasma osmolality decreased from 290 +/- 2 to 280 +/- 1 mosmol/l, and remained low. There was a median 6-fold increase in plasma vasopressin concentration, while saline did not elicit vasopressin release. Despite the absence of electrolytes in glycine solution, the urinary excretion of sodium amounted to 106 +/- 40 mmol. We conclude that i.v. infusion of 1.5% glycine solution in sheep causes a transient circulatory strain and natriuresis. Moreover, a vasopressin-mediated reduction of maximal water excretion contributes to persisting hypoosmolality.

Ethanol monitoring of transurethral prostatic resection during inhaled anesthesia.

The purpose of this study was to examine the precision of a method of breath-alcohol analysis used to monitor absorption of irrigating fluid during transurethral resection of the prostate performed under inhaled anesthesia. A breath-alcohol analyzer (Alcolmeter SD-2) was placed between the endotracheal tube and the Bains' circuit. The concentration of ethanol in the breath, serum sodium concentration, and volumetric fluid balance were measured at 10-min intervals during 38 operations when the irrigating fluid contained 1.5% glycine and 1% ethanol. Ethanol monitoring detected absorption rates that exceeded 14 +/- 8 mL/min (mean +/- SD). In 17 patients in whom hyponatremia developed immediately in connection with absorption, the volume of irrigating fluid absorbed (up to 1950 mL) could be predicted from a single expired-breath test with a standard error of 325 mL. When the alcohol measurements were corrected for absorption time, the standard error was 215 mL. Seven other patients received 2.2% wt/vol glycine as irrigating fluid, and ethanol (0.35 g/kg) was administered by intravenous infusion. The direct and indirect measurements of the blood-alcohol concentration agreed well. These results confirm that ethanol monitoring is a viable technique during inhaled anesthesia for transurethral resection of the prostate.

Pharmacokinetics of ethanol in plasma and whole blood: estimation of total body water by the dilution principle.

The pharmacokinetics of ethanol in plasma and whole blood have been investigated and the results used to estimate the volume of total body water (TBW) by means of the dilution principle. Fifteen men (mean age 62 y) were given 0.6 g ethanol/kg body weight as an intravenous infusion over 1 h. The peak concentration of ethanol in plasma was 120 mg.dl-1 compared to 108 mg.dl-1 for whole blood. The disappearance rate of ethanol from plasma was 18.6 mg.dl-1.h-1 compared to 17.0 mg.dl-1.h-1 for the whole blood concentration-time data. The apparent volume of distribution of ethanol (Vz) was 0.54 l.kg-1 according to plasma kinetics compared to 0.59 l.kg-1 for the kinetics derived from whole blood. The mean area under the curve (AUC) was 294 mg.dl-1 x h for plasma kinetics compared to 266 mg.dl-1 x h for whole blood. The TBW was 40.9 l or 50.9% of body weight for the plasma concentration-time data. This agreed well with the 40.3 l or 50.1% of body weight obtained using whole blood.

Effects of 1.5% glycine solution with and without 1% ethanol on the fluid balance in elderly men.

Ten male patients scheduled for transurethral prostatic resection (aged 57-79) were given irrigating fluid by intravenous infusion at 50 ml.min-1 over 20 min. Each patient was subjected to two infusions: 1.5% glycine in water on one occasion, and the same solution but with 1% ethanol added on the other. Urine and blood samples were collected at regular intervals for up to 2 h after infusion, and the changes in the distribution of water and electrolytes between fluid compartments were calculated. Transient prickling skin sensations were frequently reported effects of the infusions. Two patients experienced visual disturbances. There were no changes in the blood ammonia and plasma vasopressin levels. During the infusions, the estimated blood volume and the total plasma sodium and potassium content increased. The solutions produced osmotic diuresis with increased urinary excretion of water and electrolytes. After ending the fluid administration, blood volume was rapidly restored. Over the following 120 min the irrigant water was redistributed intracellularly or removed by urinary excretion. The addition of ethanol did not alter the overall effects of glycine solution on the fluid balance.

Expired-breath ethanol measurement in chronic obstructive pulmonary disease: implications for transurethral surgery.

If ethanol is added to the irrigant used during transurethral prostatic resection, the absorption of fluid can immediately be detected by measuring the ethanol concentration in the expired breath. To evaluate this method further, we studied the influence of chronic obstructive pulmonary disease (COPD) on the agreement between expired-breath and blood-ethanol concentrations. In 14 men with a mean age of 62 years (range 55-68), the concentrations of ethanol in whole blood and end-expired breath were measured at 12 exactly timed intervals before, during, and after an intravenous infusion of 0.6 g.kg-1 ethanol for 60 min. The pulmonary function was normal in seven of the subjects (control group) whereas the other seven suffered from severe COPD (study group). The results show that the accuracy and precision of breath-alcohol analysis to predict the blood-ethanol level were poorer during the infusion of ethanol than afterwards. However, at all times of sampling the estimation of blood-ethanol concentration indirectly by analysis of breath was not significantly different for COPD patients and the control group. We conclude that ethanol monitoring of irrigant absorption can be used successfully in patients with COPD.

Vasopressin and cortisol levels in response to glycine infusion.

The plasma vasopressin and serum cortisol concentrations were recorded in 7 healthy volunteers receiving an intravenous infusion of 1 l of isosmotic (2.2%) glycine solution during 20 min. The infusion elicited a significant increase in the plasma vasopressin level by a mean of 60% (SEM 13) above baseline level. The serum cortisol level increased only in the patient who developed signs of glycine toxicity. These results suggest that a glycine solution has water-retaining properties by stimulating the vasopressin secretion but usually not by increasing cortisol secretion.

Distribution of ethanol and water between plasma and whole blood; inter- and intra-individual variations after administration of ethanol by intravenous infusion.

Hospital patients (n = 17) received 0.216 mmol/min kg body weight of ethanol as an intravenous infusion over 60 min. At fixed time intervals during and after administration, two consecutive samples of whole blood (5 ml each) were taken from a cubital vein. The plasma fraction was obtained by centrifugation of one of the tubes. The concentrations of ethanol in whole blood and plasma were determined by headspace gas chromatography and the water contents of the specimens by desiccation. The mean plasma:whole blood ratio of ethanol was 1.10:1, range 1.03:1 to 1.24:1 (n = 159). The components of variance (SD) within subjects and between subjects were 0.0293 (CV 2.7%) and 0.0165 (CV 1.5%) respectively. The 95% confidence interval ranged from 1.03:1 to 1.16:1 for a single new determination in a subject from the same population. The average water content in plasma and whole blood were 91.8% w/w (SD 0.49) and 80.1% w/w (SD 1.03) respectively. Neither the mean plasma:blood ratio of ethanol nor the water content of the specimens depended on sampling time after ethanol administration.

Intravenous infusion of irrigating fluids containing glycine or mannitol with and without ethanol.

Irrigating fluids consisting of 5% mannitol, 3% mannitol + 1% ethanol, 2.2% glycine and 1.5% glycine + 1% ethanol in water were given by intravenous infusion to seven healthy volunteers at a constant rate of 50 ml./min. over 20 min. The irrigants containing glycine produced hyperkalemia and usually prickling and burning skin sensations and slight nausea. The severity of the symptoms apparently correlated to the blood ammonia level, which increased significantly after the glycine but not after the mannitol infusions. With 5% mannitol, there was a pronounced transient increase of the blood volume and a prolonged hyponatremia. There were no differences between the irrigants in respect to their effects on blood pressure and urine excretion. Ethanol caused no adverse effects and allowed the fluid supplementation to be followed by expired breath tests.