Factors influencing the osmolality and the concentrations of blood haemoglobin and electrolytes during transurethral resection of the prostate

Twenty patients undergoing transurethral resection of the prostate (TUR) were followed every 10 min intraoperatively as well as 1 and 2 h postoperatively with measurements of blood haemoglobin concentration (B-Hb), serum sodium (S-Na), serum potassium (S-K), serum osmolality (S-osmol), blood loss, central venous pressure and volumetric determination of the irrigating fluid absorption. Changes in B-Hb correlated well with the sum of acetated Ringer solution given and intravascular irrigating fluid absorption. A transient decrease in S-Na of 1-4 mmol/l followed absorptions less than 300 ml. With larger intravascular absorptions, three stages of dilutive changes in S-Na and B-Hb are described. Extravascular absorptions resulted in mild blood parameter changes at various times after their occurrence. Absorption of irrigating fluid was associated with an increase in S-K. S-osmol decreased in conjunction with some absorptions, although the irrigating fluid was isotonic. Postoperative analyses of blood parameters gave only limited information about intraoperative complications. The only consistent pattern was associated with intravascular irrigating fluid absorption.     

Changes in intravesical pressure during irrigating fluid absorption in transurethral prostatic surgery

Summary Continuous recording of intravesical pressure (IVP) and incremental volumetric measurements of irrigating fluid absorption were performed during 37 transurethral resections of the prostate (TUR). Absorption which resulted in concomitant dilutional changes in peripheral blood, indicating intravascular absorption, was associated with prolongation of the time required to increase the IVP. There was an inverse relation between the change in maximum IVP and the rate of irrigating fluid absorption. Abges in peripheral blood, indicating extravascular absorption, was associated with similar changes in IVP parameters but the critical pressure for absorption was lower.     

Irrigation fluid absorption during transurethral resection of the prostate: spinal vs. general anaesthesia

BACKGROUND: The absorption of irrigation fluid during transurethral resection of the prostate (TURP) is determined primarily by hydrostatic pressure in the bladder and prostatic venous pressure. In comparison to spontaneously breathing patients, patients undergoing mechanical ventilation with positive pressure have a raised central venous pressure and a reduced venous return, both of which can influence intravascular absorption. The purpose of the prospective study was to compare the effects of general (GA) and spinal anaesthetic (SA) techniques on the perioperative absorption of irrigating fluid in patients undergoing TURP. METHODS: Forty patients undergoing TURP were randomised and assigned either to group GA or SA. Irrigating fluid absorption was traced by adding 1.5% (w/v) ethanol to the irrigating fluid. Perioperative blood ethanol concentration (BEC), haemoglobin concentration, haematocrit, serum sodium concentration and central venous pressure (CVP) were measured at 10-min intervals during TURP and at 30-min intervals while patients were recovering. Absorption routes were indexed by the BEC and changes in serum sodium concentrations. Where the BEC was greater than 0.05 mg.mL-1, absorption of irrigating fluid was assumed. For assessing the volume of irrigating fluid absorbed, the maximum BEC, the absorption rate, the area under the BEC curve (AUC), and the volumes calculated according to the Hahn nomogram (Volin) for each patient were taken into consideration. RESULTS: There were 15 cases of irrigating fluid absorption in patients receiving GA (75%), and 11 in those receiving SA (55%). CVP was significantly lower in spontaneously breathing patients with SA as compared to those with GA (P < 0.05). In patients with irrigating fluid absorption the maximum BEC (P < 0.02), as well as the rate of irrigant fluid absorption (P < 0.01), were significantly higher amongst patients receiving SA. In this group, the calculated area under the curve and the absorbed fluid volumes determined with the nomogram were significantly increased (P < 0.05). CONCLUSION: The absorption of irrigation fluid during the TURP is significantly more marked amongst spontaneously breathing patients with regional anaesthesia in comparison to patients undergoing general anaesthesia with positive pressure ventilation. The markedly lower central venous pressure before the start of irrigation should be considered as a possible cause of this effect.     

Ethanol monitoring of irrigating fluid absorption in transcervical resection of the endometrium

Background . We evaluated the precision in using ethanol to indicate and quantify absorption of irrigating fluid during transcervical resection of the endometrium.
Methods . The ethanol concentration in the expired breath, the serum sodium level, the blood loss and the volumetric fluid balance were measured over 10-min periods during 62 operations. A solution containing glycine 1.5% and ethanol 1% was used to irrigate the uterus.
Results . Most principles previously outlined for ethanol monitoring in transurethral prostatic surgery could also be applied in endometrial resection.
In the 21 patients who showed the intravascular pattern of ethanol changes, the breath alcohol measurement corrected for absorption time predicted the volume of irrigant absorbed {up to 2,531 ml) with a standard error of 230 ml at the end of any 10-min period of absorption. Repeated measurement of serum sodium indicated intravascular fluid absorption with practically the same precision as the breath test.
Extravascular absorption was found in 14 patients. In these operations, the volume of irrigant absorbed (up to 1,767 ml) could be predicted with a standard error of 92 ml from the ethanol concentration at the plateau level attained after absorption had occurred.
Conclusion . Ethanol monitoring is precise enough to allow monitoring of irrigating fluid absorption in endometrial resection.     

Acid-base status following glycine absorption in transurethral surgery.

Forty patients were studied at precisely timed 10 min intervals during transurethral prostatic resection under epidural analgesia. Blood gases, serum sodium, and volumetric irrigating-fluid balance were measured. A decrease in the serum sodium level of less than 5 mmol litre-1 was recorded in 28 patients (the 'normal TUR' group). In 12 patients, the decrease was 5 mmol litre-1 or more, which corresponded to an average absorption of irrigant of 1 litre of 2.2% glycine solution (range 0.6-2.9; the 'absorption' group). Mild metabolic acidosis often developed during the operations, but this was of similar degree in the two groups. It was concluded that uptake of irrigating fluid containing glycine does not alter the acid-base status so long as the TUR syndrome does not develop.     

Relations between irrigant absorption rate and hyponatraemia during transurethral resection of the prostate

The serum sodium concentration (S-Na) and the volume of irrigating fluid absorbed were measured during 10-min periods in the course of 85 transurethral resections of the prostate (TUR). The hyponatraemic response to absorption of the irrigant was found to be dependent on the volume of fluid absorbed and the time required for the absorption. During the first 10 min of absorption the distribution volume of the irrigating medium was roughly equal to the extracellular space, but after this period the volume was greater. The sodium level could be compensated for further absorption to the extent of 200-300 ml irrigant per 10-min period; when this volume was exceeded, hyponatraemia was aggravated. The results indicate that in the development of the very low S-Na level typical of a severe TUR reaction, a rapid massive absorption is a more important factor than a large total absorbed volume.     

The volumetric fluid balance as a measure of fluid absorption during transurethral resection of the prostate

To evaluate the usefulness of the volumetric fluid balance for indicating and quantifying fluid absorption during transurethral resection of the prostate, 62 patients showing fluid absorption on ethanol monitoring (control method) were selected from a series of 410 operations. The volumetric fluid balance, which was measured as the difference between the input and output of irrigating fluid with and without a correction for the blood loss, proved to be an unreliable clinical tool for measuring the absorption. It indicated that fluid absorption occurred only in 40 or 18 of the 62 patients, depending on whether a correction for blood loss was made or not, the volume being only 59% and 71% (median), respectively, of that obtained by the control method. The absorption averaged 1 L in the patients in whom the volumetric measurements did not indicate absorption. The incidence of symptoms of the 'transurethral resection syndrome' increased with the absorbed fluid volume only when measured by the control method.     

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.     

Trocar cystostomy during transurethral prostatic resection

A new suprapubic trocar for constant drainage of irrigating fluid during transurethralresection of the prostate was studied in 87 patients: The irrigating fluid height was 60 cm. above the prostatic fossa in 61 patients and 40 cm. in 26 patients. The absorption of irrigating fluid during resection was measured by volumetric and radioisotopic methods and was compared with and without use of trocar in the two patient groups. In the 40-cm. group, but not in the 60-cm. group, the use of trocar cystostomy lowered the total as well as the intravascular absorption of irrigating fluid to low and clinically insignificant amounts. The low bladder pressure (average 8 cm.) explained the low absorption. The use of the trocar in this group also resulted in lower blood loss per gram resected tissue and less operating time per gram tissue removed. Use of the trocar in transurethral prostatic resection represents a technical advantage over conventional techniques, since it allows uninterrupted resection at a low bladder pressure.     

Iglesias resectoscope with simultaneous irrigation, suction and low intravesical pressure.

A resectoscope with continuous irrigation, suction and low intravesical pressure has been described. Advantages of this instrument include: no interruption, better endoscopic vision by a continuous clear inflow of more than 500 ml/min at 70 cm pressure, less bleeding, no air bubbles, constant intravesical pressure less than 10 mm Hg during TUR, permitting the absorption of the irrigant, shorter operating time, easier teaching and no more wet floor and wet surgeon. Since the entire amount of irrigating fluid is collected, blood loss can be calculated and the amount of absorption determined.     

INFLUENCE OF VARIATIONS IN BLOOD HAEMOGLOBIN CONCENTRATION ON THE CALCULATION OF BLOOD LOSS AND VOLUMETRIC IRRIGATING FLUID BALANCE DURING TRANSURETHRAL RESECTION OF THE PROSTATE

Blood loss in 38 patients undergoing transurethral resectionof the prostate (TURP) was calculated in four different waysby using various reference blood haemoglobin determinations(B-Hb) during the course of preparation and surgery. Blood lossbecame greater the later the B-Hb was drawn. This increase wasbecause variations in B-Hb acted to underestimate the loss ofplasma. The variations also distorted the irrigating fluid balanceto give too low values for the absorption of irrigating fluid.It is possible to correct for the errors in blood loss and volumetricfluid balance by the use of haemodilution factors. Haemodilutionwas greater in patients with complications such as absorptionof irrigating fluid or excessive blood loss than in patientswithout such features if Ringer's acetate was used for i.v.fluid supplementation. With dextran 40, all patients had a similardegree of haemodilution.     

Monitoring irrigating fluid absorption during transurethral resection of the prostate (TURP); a comparison between 1 and 2% ethanol as a tracer

In a series of 35 transurethral resections of the prostate 1% ethanol was compared to 2% ethanol as a marker of the irrigating fluid. The ethanol concentration in the expired breath of the patient (EB-ethanol) correlated significantly to the irrigant absorption, as measured volumetrically, and to the change in the serum sodium concentration at 10-min intervals during the operation. The pattern of changes in EB-ethanol indicated whether the main part of the absorption entered through the intravenous or the extravascular route. With 1% ethanol added to the irrigating solution the absorption of 100-150 ml in 10 min could readily be detected. The sensitivity was twice as great with 2% ethanol; however, 1% ethanol is sufficient for routine procedures as it permits absorption to be detected long before it is large enough to produce a TUR syndrome. Monitoring ethanol in the expired breath provides the surgeon with an instrument to check that preventive steps against further absorption are effective.     

Early detection of the TUR syndrome by marking the irrigating fluid with 1 % ethanol

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.     

Water and electrolyte changes during transuretheral resection of the prostate under spinal anaesthesia

Systemic absorption of irrigating fluid during TUR prostatectomy under spinal anaesthesia was measured in 40 patients and correlations made under clinical, hemodynamic and laboratory observations. Results showed that the CVP monitoring is a helpful parameter in early detection of the hypervolemic hyponatremic syndrome. Serial determination of serum sodium level is important in detecting hyponatremia. Out of the 40 patients, one patient developed acute hypervolemic hyponatremic syndrome. The syndrome was detected early by the significant rise in CVP and the drop in serum sodium level and P.C.V. Intravenous infusion of 250 ml hypertonic saline slowly was followed by marked diuresis and uneventful recovery.     

Immediate detection of irrigant absorption during transurethral prostatectomy: case report

A transurethral prostatic resection is described in which immediate detection of a rapid massive irrigant absorption could be made by the use of ethanol-tagged irrigating fluid and repeated measurements of the ethanol concentration in the patient's expired breath. This monitoring enabled the surgeon to prevent further absorption by concluding the operation before symptoms resulted. Furosemide was given immediately to promote renal excretion of the absorbed irrigant, and the intravenous infusions were temporarily restricted to limit the intravascular fluid load. In retrospect, volumetric measurement showed that a total of 2410 ml of irrigant had been absorbed.     

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.     

加压灌流辅助经皮肾镜术中血流动力学及电解质平衡的变化

目的 探讨加压灌流辅助经皮肾镜取石术(PCNL)中灌流液吸收对血流动力学和电解质平衡的影响.方法 上尿路结石患者89例,其中肾结石65例、输尿管上段结石24例.男62例、女27例.中位年龄42(16～69)岁.均采用加压灌流辅助PCNL,以生理盐水为灌流液.灌流前及术中每30 min为记录时间点,监测心率(HR)、中心静脉压(CVP);胸电生物阻抗法连续监测心输出量(CO)、每搏输出量(SV)、胸腔液体含量(TFC)、外周血管阻力(SVR);测定手术前后动脉血酸碱度、碱剩余,静脉血钠、钾、氯浓度.TFC、CO、SV、SVR、HR变化采用单因素方差分析,CVP、TFC与灌流时间、灌流液总量、灌流速度的相关性行线性相关分析.手术前后血浆电解质等比较采用配对t检验.结果 89例灌流时间(105±40)min,灌流液用量(18 391士4895)ml,灌流速度(174.46±58.28)ml/min.灌流前后HR、C0、SV、SVR比较差异无统计学意义(P>0.05);CVP、TFC与灌流速度、灌流时间、灌流液量呈线性正相关.手术前后血钠、钾、氯浓度比较差异无统计学意义(P>0.05).5例术中出血明显者CVP增加至(14.8±1.4)cm H2O(1cm H2O=0.098 kPa)、TFC增加至(47.3±1.7)kOhm,并出现代谢性酸中毒,静脉使用呋塞米20mg后15min复测CVP降至(6.5±1.7)cm H2O、TFC降至(41.0±2.1)kOhm.未发生严重并发症.结论 器官代偿功能正常的患者加压灌流辅助PCNL术中灌流液吸收对循环功能及电解质平衡无明显影响.高危病例应注意监测血流动力学和电解质平衡,降低灌流压力和灌流速度,缩短手术时间或分期手术.     

Use of ethanol as marker substance to increase patient safety during transurethral prostatic resection. Screening investigation of irrigating fluid absorption in four hospitals and comparison of experienced and inexperienced urologists

Of 472 patients at four different hospitals electively undergoing transurethral resection of the prostate (TURP), 192 received Sorbitur as an irrigating fluid with 2% ethanol (w/v) as a marker. Using a breath analyzer (Alcol-meter), the amount of ethanol in expired air was measured regularly during the operation to detect the absorption of irrigating fluid. The ethanol concentration in expired air was plotted against time. The time-ethanol concentration product was used as a measurement of absorbed ethanol marked irrigating fluid. A unit of more than 2.5 was considered to be a major absorption with possible clinical significance. This criterion was fulfilled in 24 percent of the patients. Postoperative serum sodium was shown to decrease more in patients with major absorption than in patients with minor absorption in comparison to preoperative values. The weight of resected tissue and the bleeding per resected gram of tissue was higher in the patients with major absorption, but the resected tissue per operating time was the same in both groups. The experienced urologists had as many patients with absorption as did the inexperienced ones. Ethanol-marked irrigating fluid is a simple, safe, noninvasive, rapid, and cheap method of detecting absorption of irrigating fluid thus increasing patient safety during TURP. This method indicates absorption before clinical signs and symptoms of the TUR syndrome occur. It also provides an easy method for estimating the frequency of absorption of irrigating fluid routinely in clinical work.     

The addition of ethyl alcohol to the irrigating fluid. Monitoring fluid absorption during transurethral resection of the prostate]

The absorption of irrigation solution during transurethral prostatic resection may lead to the life-threatening condition of the so-called TUR syndrome. For a long time no early recognition procedure was easily and routinely available. This study was set up to investigate the effectiveness of ethanol as an early indicator of beginning absorption, as described by Hulten. Ethanol was therefore added to the irrigating fluid as a marker, and alcohol concentrations were measured in the exhaled breath. METHODS. For measurement of alcohol an Alcotest monitor 7110, Dr?gerwerk (Lübeck, FRG) was used. In preliminary experiments with 13 healthy volunteers the lowest amount of measurable i.v.-administered 2% Ringer-ethanol solution was found to be about 200 ml. The irrigating fluid used was a 2% ethanol-mannitol/sorbitol solution. RESULTS. The control of breath and blood alcohol levels in 10 patients undergoing transurethral bladder surgery showed that there was no absorption of alcohol across the internal bladder lining. Of 52 patients, who had to undergo transurethral prostatic resection, 23 had positive breath alcohol values of up to 0.81/1000. In 6 patients the blood alcohol levels only were elevated (max. 0.18/1000). In 23 other patients no increased blood or breath alcohol levels were detectable. The negative breath alcohol levels in 6 patients were most probably attributable to low breath volumes due to lack of cooperation caused by pre- and/or intraoperative sedation. There were no significant changes in central venous pressure, mean arterial pressure or heart rate even at the time of maximal alcohol levels, compared with initial values. These parameters thus cannot be used for the early recognition of beginning absorption. Simultaneous monitoring of serum sodium concentrations revealed significant decreases at the time of maximal breath alcohol levels. Yet, the first indication of beginning absorption was always a positive alcohol level. Serum sodium changes followed later with increasing alcohol levels. Sodium concentration did not drop before a positive alcohol level was measured in any of these cases. CONCLUSION. It was thus proven that the addition of ethanol to the irrigating fluid and monitoring of the patient's exhaled breath with the Alco-testmonitor is a simple, non-invasive system that can be routinely used for early detection of absorption during transurethral prostatic resection. Adequate adjustment of the further course of the operation was possible. The dreaded TUR syndrome did not develop in any of the patients monitored in this way.     

Validation of the ethanol breath test and on-table weighing to measure irrigating fluid absorption during transurethral prostatectomy

OBJECTIVE: To determine the agreement between on-table weighing and the ethanol breath test in measuring the fluid absorption of patients during transurethral prostatectomy (TURP), and to assess the practicality of on-table weighing in the clinical setting. PATIENTS AND METHODS: The absorption of irrigating fluid by the patient during TURP can lead to adverse sequelae, including cardiac stress. Despite modern techniques irrigant may still be absorbed and therefore methods to detect absorption are important. Most methods are impractical or inaccurate, but the expired ethanol technique and continuous on-table weighing are more promising. TURP was undertaken in 44 men (mean age 71 years) using continuous flow 1.5% glycine/1% ethanol as the irrigating solution. Intraoperative irrigant absorption was calculated by the ethanol breath test, using published formulae. Absorption measured by the weighing machine was calculated as (weight gain + blood loss - fluid given), and blood loss by the Hemocue method. RESULTS: The mean (sd) resected weight was 23 (14) g at a mean resection rate of 0.74 g/min. The mean (range) absorption using the balance was 456 (- 343 to 2486) mL, and using the ethanol breath test was 435 (44-2750) mL, with the mean of the differences being - 17 mL, with a 95% confidence interval (CI) of - 81 to -40, the 95% limits of agreement being - 389 to 356 mL (95% CI - 458 to - 337 and 297 to 418 mL). CONCLUSIONS: Both methods are comparable and measure irrigating fluid absorption to levels of accuracy that are useful clinically. Either method could (and should) be used in routine practice.