Coma from hyponatremia following transurethral resection of prostate

Successful Treatment of Pulmonary Edema Caused by Transurethral Resection of the Prostate Syndrome

BACKGROUND

Transurethral resection of the prostate (TURP) syndrome is a complication of transurethral resection of the prostate procedure. The incidence of TURP syndrome ranges from 0.78% to 1.4%. This syndrome is caused by excessive absorption of electrolyte-free and hypotonic washing solution. The fluids absorb into the circulation, which leads to heart failure, hyponatremia, and a decrease in serum osmolality. Cerebral edema, coma, pulmonary edema, cardiovascular collapse, and even death are common complications.

CASE PRESENTATION

We report a patient who suffered severe TURP syndrome after transurethral resection of the prostate procedure. Clinical manifestations were pulmonary edema and respiratory failure. The concentration of Na+ was 112.6 mmol/l, which was severe hyponatremia. The serum osmolality pressure was 234mOsmol/kg, pH was 7.23, pO2 was 45mmHg and pCO2 was 44mmHg. The patient had successfully recovered after being used CPAP-PSV Pro breathing through a mask with + 5cmH2O of PEEP, 8cmH2O of supporting pressure, 70-100% of FiO2, 20mg furosemide of intravenously, 150 mL of 3% NaCl, and 100mL natribicarbonate 8.4%.

CONCLUSION

TURP syndrome is a life-threatening complication of transurethral resection of the prostate procedure, which is caused by excessive absorption of electrolyte-free and hypotonic washing solution. Therefore, the patient should be monitored seriously, diagnosed early, and treated promptly.

The use of inhaled sevoflurane during operative hysteroscopy is associated with increased glycine absorption compared to intravenous propofol for maintenance of anesthesia

STUDY OBJECTIVE

To compare the effects of anesthesia maintenance drugs (inhaled sevoflurane versus intravenous propofol) used in general anesthesia on the absorption of glycine 1.5% solution during hysteroscopy.

DESIGN

Prospective comparative study.

SETTING

Tertiary care university hospital.

PATIENTS

One hundred fifteen women undergoing hysteroscopy.

INTERVENTIONS

Women were assigned to receive general anesthesia with inhaled sevoflurane (n = 77) or intravenous propofol (n = 38) to maintain anesthesia.

MEASUREMENTS

The primary endpoint was clinically relevant glycine 1.5% absorption (>1000 mL), while secondary endpoints were the median of glycine absorption, operative time, complications and the incidence of discontinuation of the hysteroscopic procedure due to excessive glycine 1.5% absorption.

MAIN RESULTS

Maintenance with sevoflurane produced significantly increased absorption of glycine 1.5% solution compared to intravenous anesthesia (264 vs 202 mL, P = .007). Clinically relevant absorption rates (>1000 mL) were observed in the sevoflurane group (P = .04) while none of the women receiving intravenous anesthesia reached this absorption level. No cases of severe post-operative hyponatremia (Na(1+)<125 mmol/L) or adverse events derived from glycine 1.5% absorption were reported. No major complications (such as perforations, severe hemorrhage or infection) were presented during the interventions.

CONCLUSIONS

The results of the present study show that the use of inhaled sevoflurane is associated with significantly increased glycine 1.5% absorption compared to intravenous propofol for the maintenance of anesthesia. However, further randomized controlled trials are needed to assess the possible mechanisms and risk factors involved in the higher absorption induced by sevoflurane.

Fluid absorption and the ethanol monitoring method

BACKGROUND

Fluid absorption is a well-known complication of endoscopic surgeries, such as transurethral prostatic resection and transcervical endometrial resection. Absorption of electrolyte-free fluid in excess of 1 L, which occurs in 5% to 10% of the operations, markedly increases the risk of adverse effects from the cardiovascular and neurological systems. Absorption of isotonic saline, which is used with the new bipolar resection technique, will change the scenario of adverse effects in a yet unknown way. Hyponatremia no longer occurs, but marking the saline with ethanol reveals that fluid absorption occurs just as much as with monopolar prostate resections.

METHODS

Ethanol monitoring is a method for non-invasive indication and quantification of fluid absorption that has been well evaluated. By using an irrigating fluid that contains 1% of ethanol, updated information about fluid absorption can be obtained at any time perioperatively by letting the patient breathe into a hand-held alcolmeter.

RESULTS

Regression equations and nomograms with variable complexity are available for estimating how much fluid has been absorbed, both when the alcolmeter is calibrated to show the blood ethanol level and when it is calibrated to show the breath ethanol concentration. Examples of how such estimations should be performed are given in this review article.

CONCLUSIONS

The difficulty is that the anesthesiologist must be aware of how the alcolmeter is calibrated (for blood or breath) and be able to distinguish between the intravascular and extravascular absorption routes, which give rise to different patterns and levels of breath ethanol concentrations.

Fluid volume kinetics of dilutional hyponatremia; a shock syndrome revisited

OBJECTIVE

To evaluate whether the pathophysiology of shock syndromes can be better understood by comparing central hemodynamics with kinetic data on fluid and electrolyte shifts.

METHODS

We studied the dilutional hyponatremic shock that developed in response to overhydration with electrolyte-free irrigating fluid - the so-called 'transurethral resection syndrome' - by comparing cardiac output, arterial pressures, and volume kinetic parameters in 17 pigs that were administered 150 ml/kg of either 1.5% glycine or 5% mannitol by intravenous infusion over 90 minutes.

RESULTS

Natriuresis appeared to be the key factor promoting hypovolemic hypotension 15-20 minutes after fluid administration ended. Excessive sodium excretion, due to osmotic diuresis caused by the irrigant solutes, was associated with high estimates of the elimination rate constant (k10) and low or negative estimates of the rate constant describing re-distribution of fluid to the plasma after translocation to the interstitium (k21). These characteristics indicated a high urinary flow rate and the development of peripheral edema at the expense of plasma volume and were correlated with reductions in cardiac output. The same general effects of natriuresis were observed for both irrigating solutions, although the volume of infused 1.5% glycine had a higher tendency to enter the intracellular fluid space.

CONCLUSION

Comparisons between hemodynamics and fluid turnover showed a likely sequence of events that led to hypovolemia despite intravenous administration of large amounts of fluid.

Glycine 1.5% for irrigation should be abandoned

BACKGROUND

Glycine 1.5% has long maintained a dominating role as an irrigating solution for monopolar transurethral resection of the prostate (TURP), as well as for certain other transurethral procedures.

MATERIALS AND METHODS

This review summarizes the findings of systematic experimental and clinical studies in which glycine 1.5% for irrigation was infused/absorbed and the outcome compared to at least one other irrigating fluid, including the isotonic saline used for bipolar TURP.

RESULTS

There were 11 studies in animals, 3 in volunteers and 6 in patients undergoing TURP. With only one exception, which is probably due to low power, these studies either show a poorer outcome after administration or absorption of glycine solution or else that glycine 2.2% is more toxic than glycine 1.5%. The poorer outcomes consisted of more tissue damage or higher mortality (animals) or more symptoms (volunteers and patients).

CONCLUSION

The safety of monopolar TURP would be improved by replacing glycine 1.5% with some other electrolyte-free fluid. The author argues that glycine 1.5% should be abandoned completely.

Transurethral resection of the prostate syndrome: almost gone but not forgotten

Transurethral resection of the prostate (TURP) syndrome is a rare but potentially fatal syndrome with multifactorial pathophysiology that is now better understood. Unfortunately, despite this improved understanding, it is not yet obsolete and still remains a risk. Many reviews of TURP syndrome have been presented from an anesthetic perspective; this review reflects more the urologic perspective with emphasis on the importance of multidisciplinary management of this complex syndrome. We present a review of TURP syndrome that specifically assesses advances in the understanding of risk factors, pathophysiology, and techniques used to prevent this syndrome. The databases Medline, Embase, Cochrane Controlled Trial Register, and Database of Abstracts of Reviews of Effects were systematically reviewed from inception to April 2009 for the keywords TUR (P), TUR (P) syndrome, and transurethral resection of prostate. There was no language restriction for our search. Randomized controlled trials, review articles and case series were included in our search. Our review showed a declining trend in the incidence of TURP syndrome despite TURP remaining the gold standard for the management of benign prostatic obstruction. Technologic advances using an array of laser techniques, the use of bipolar circuitry, together with advances in training techniques have helped minimize the risk of development of this syndrome. This review demonstrates the complexity of TURP syndrome. Even with a greater understanding of the pathophysiology, it highlights the unpredictability of the syndrome from presenting symptoms, preventative measures, and management. TURP syndrome cannot be protocol driven and the need for vigilance, a high index of suspicion, intensive monitoring, and a multidisciplinary approach is vital.

Fluid absorption in endoscopic surgery

Fluid absorption is an unpredictable complication of endoscopic surgery. Absorption of small amounts of fluid (1-2 litre) occurs in 5-10% of patients undergoing transurethral prostatic resection and results in an easily overlooked mild transurethral resection (TUR) syndrome. Large-scale fluid absorption is rare but leads to symptoms severe enough to require intensive care. Pathophysiological mechanisms consist of pharmacological effects of the irrigant solutes, the volume effect of the irrigant water, dilutional hyponatraemia and brain oedema. Other less widely known factors include absolute losses of sodium by urinary excretion and morphological changes in the heart muscle, both of which promote a hypokinetic circulation. Studies in animals, volunteers and patients show that irrigation with glycine solution should be avoided. Preventive measures, such as low-pressure irrigation, might reduce the extent of fluid absorption but does not eliminate this complication. Monitoring the extent of absorption during surgery allows control of the fluid balance in the individual patient, but such monitoring is not used widely. However, the anaesthetist must be aware of the symptoms and be able to diagnose this complication. Treatment should be based on administration of hypertonic saline rather than on diuretics. New techniques, such as bipolar resectoscopes and vaporizing instead of resecting tissue, result in a continuous change of the prerequisites for fluid absorption and its consequences.

A comparison of the effect of 1.5% glycine and 5% glucose irrigants on plasma serum physiology and the incidence of transurethral resection syndrome during prostate resection

OBJECTIVE

To examine changes in the pathophysiology and frequency of the transurethral resection (TUR) syndrome with two irrigation fluids, as variable amounts of irrigation fluid are absorbed during TUR of the prostate (TURP), and although polar solutes are required to prevent an effect on diathermy, the solutes may have effects when absorbed.

PATIENTS AND METHODS

Between December 2001 and March 2003, 250 patients were included in a prospective randomized trial comparing glycine 1.5% with 5% glucose irrigation fluids. We measured blood loss, fluid absorption, temperature change, biochemistry including a glycine assay, and peri-operative symptoms. Blood samples were taken immediately before and immediately, 5 and 24 h after TURP. Irrigating fluid absorption during TURP was measured with 1% ethanol as a marker and breath ethanol measurements. Operative details were recorded, including the type of anaesthesia (with or with no sedation), resection time and weight of resected tissue. Peri-operative symptoms were documented prospectively. TUR syndrome was defined as a serum sodium level of < or = 125 mmol/L with two or more associated symptoms or signs of TUR syndrome.

RESULTS

Five (2%) patients had TUR syndrome; all five were irrigated with glycine, although this difference was not statistically significant (P = 0.06). Of the five men, three had hypotension, four were tired, one was nauseous, two had parasthesia, two had 'uneasiness', one had blurred vision and two were confused; none had chest pain. There was a large variation between the groups in the level of glycine assayed immediately after TURP; a high glycine level was associated with the TUR syndrome (P = 0.01). There was no difference between the groups in levels of sodium, potassium, urea, creatinine, osmolality, calcium, haematocrit, albumin serum levels or peri-operative blood loss (defined as a change from before to after TURP in haemoglobin level, accounting for transfusions).

CONCLUSIONS

An increase in serum glycine was associated with TUR syndrome; there were large variations in the amounts of glycine absorbed, reaching levels many times the upper limit of normal. In other studies, glycine was reportedly toxic, and that the levels recorded were many times the upper limit of normal may have both immediate and long-term effects.

Natriuresis and “dilutional” hyponatremia after infusion of glycine 1.5%

STUDY OBJECTIVE

To challenge the view that the hyponatremia resulting from absorption of glycine 1.5% is attributed to the expansion of the extracellular fluid (ECF) volume, and that the change in serum sodium is therefore widely used to calculate the amount of irrigant absorbed.

DESIGN

Retrospective analysis of six studies.

SETTING

University-affiliated hospital.

MEASUREMENTS

Approximately 1.2 L of glycine 1.5% was infused in 23 volunteers (two studies), 1 L in 10 prostatectomy patients, 2.4 L in 6 sheep, 4 L in 6 other sheep, and 3 L in 9 piglets. The distribution of the irrigant water was estimated from the difference between the measured and the expected serum sodium levels, taking into account the urinary losses of sodium and water.

MAIN RESULTS

Between 30% and 50% of the irrigant volume had diffused into the cells 30 minutes after the infusion, and only between 0% and 50% of the fluid remained in the ECF. One hour later, natriuresis accounted for 100% of the residual hyponatremia in the small-volume experiments, and it accounted for approximately 50% in the large-volume experiments. The change in serum sodium could not be used to quantify the small infusion volumes, but the large ones could be quantified fairly accurately if assessed at the very end of the infusion.

CONCLUSIONS

Diffusion of water into the cells and natriuresis reduced and prolonged the hyponatremia associated with infusions of glycine 1.5%. This finding makes IV fluid with sodium added a more rational alternative than furosemide in the treatment of fluid overload with this irrigating solution.

High-dose intravenous infusion of irrigating fluids containing glycine and mannitol in the pig

BACKGROUND

Large-scale absorption of electrolyte-free irrigating fluid during endoscopic surgery may result in a "transurethral resection syndrome." The severity of the syndrome can probably be modified by using mannitol 5% instead of the most widely used glycine 1.5%.

METHODS

Seventeen pigs with a mean body weight of 22 (range 19-26) kg received an intravenous infusion of 100 mL kg(-1) h(-1) of either glycine 1.5% or mannitol 5% over 90 min. Central hemodynamics, whole-body and brain oxygen consumption, intracranial pressure, blood hemoglobin, and the sodium concentrations in serum and urine were monitored for 120 min. Selected measurements were made on 6 other pigs given mannitol 3% and in 2 controls not given any fluid. Morphological examinations of the hearts were conducted.

RESULTS

Both glycine 1.5% and mannitol 5% transiently increased cardiac output, the aortic blood flow rate, and arterial pressures, but all of these parameters fell to below baseline after the infusions were ended. The intracranial pressure was lower (P < 0.05) and the oxygen consumption in the brain decreased (P < 0.001) during the infusion of mannitol 5%. Glycine 1.5% expanded the intracellular volume more than mannitol did (P < 0.002). Signs of myocardial damage were graded glycine 1.5% > mannitol 5% > mannitol 3%.

CONCLUSIONS

Massive infusion of glycine 1.5% and mannitol 5% left the pigs in a hypokinetic hypotensive state. Glycine 1.5% increased the intracranial pressure and injured the myocardium more than mannitol 5%, which then seems to be a more appropriate irrigating fluid to use during endoscopic surgery.

Transurethral resection of the prostate

Transuretheral resection of prostate (TURP) is a common operation in most hospitals. The patients are elderly and usually have concomitant diseases such as diabetes, hypertension, cardiac and respiratory ailments that increase their perioperative risk. Perioperative morbidity and mortality approaches 20% and 1% respectively. Regional anesthesia, notably spinal anesthesia, offers many advantages over general anesthesia for TURP with some evidence of lower morbidity even though similar mortality rates and overall outcomes are reported for both groups. Procedure-specific complications include TURP syndrome, bladder perforation, primary fibrinolysis, bacteremia, and septicemia. All are associated with significant morbidity and mortality but amenable to early and aggressive therapeutic intervention.

Comparison of urological irrigating fluids containing glycine and mannitol in volunteers

BACKGROUND

We compared symptoms and indices of fluid distribution after experimental administration of glycine and mannitol solutions, since these irrigating fluids are sometimes absorbed by the patient during genitourinary surgery.

METHODS

Glycine 1.5% and mannitol 3%, both with ethanol 1% added, were given by intravenous infusion at a rate of 0.5 ml/kg/min during 30 min to 12 male volunteers. Symptoms, cognitive status, hemodynamics, electrocardiogram during 24 hr, computerized tomography of the brain, bioimpedance, blood chemistry, and breath ethanol concentrations were recorded.

RESULTS

Glycine was associated with more symptoms than mannitol (P< 0.006), but the cognitive status, computerized tomography examinations, electrocardiograms, and breath ethanol concentrations did not differ between the solutions. The urinary excretion of fluid and sodium was greater after mannitol (P< 0.04), while only the glycine infusions hydrated the cells (P< 0.05). For both fluids, the intravascular and interstitial volumes were below baseline 3 hr after the experiment started (P< 0.01).

CONCLUSIONS

Glycine 1.5% had a higher tendency than mannitol 3% to cause symptoms and to accumulate in the cells.

The use of ethanol to monitor fluid absorption during transurethral resection of the prostate

Ethanol monitoring is a method for assessing fluid absorption during transurethral resection of the prostate. The method is based on the principle that absorption can be measured by expired-breath tests provided that an irrigating fluid containing ethanol 1% is used. A nomogram for transformation of the ethanol data into meaningful indices of fluid absorption, such as the volume of irrigant absorbed and the degree of hyponatraemia, has been approved for routine use within the European Union. To make a correct interpretation, however, one must learn how to distinguish the pattern of breath ethanol changes typical of absorption of fluid directly into the blood from the pattern associated with the rare intraoperative events in which fluid is deposited in a pool in the retro- or intraperitoneal space. The ethanol method is well documented, but it is still sparsely used outside Scandinavia, due to its lack of a patent and differing opinions concerning the need for measuring fluid absorption.

Endometrial Na+, K+-ATPase pump function and vasopressin levels during hysteroscopic surgery in patients pretreated with GnRH agonist

STUDY OBJECTIVE

To investigate the effects of gonadotropin-releasing hormone (GnRH) analog pretreatment on endometrial Na+, K+-adenosine triphosphatase (ATPase) pump function and peripheral blood vasopressin levels, and their role in fluid absorption and mechanisms of hyponatremia in patients undergoing hysteroscopic endometrial ablation.

DESIGN

Prospective, randomized, placebo-controlled study (Canadian Task Force classification I).

SETTING

University-affiliated hospital.

PATIENTS

Seventeen women with dysfunctional uterine bleeding.

INTERVENTION

Nine women received a GnRH analog and eight received saline approximately 6 to 8 weeks before hysteroscopic ablation by electrosurgery.

MEASUREMENTS AND MAIN RESULTS

Both before randomization and immediately before surgery, endometrial biopsy samples were obtained and numbered consecutively without patient identification. Operative hysteroscopy was performed with glycine 1.5% mixed with 2% alcohol. The amount of irrigant and irrigant deficit; blood levels of albumin and ethanol; hematocrit and hemoglobin; changes in sodium levels; and central venous pressure were compared. The Na+, K+-ATPase pump activity was significantly increased in the GnRH analog group compared with the saline group and correlated with decreased estradiol levels (0.4 +/- 0.08 vs 0.26 +/- 0.06 micro mol/min/ml). Vasopressin levels were significantly lower in the GnRH group (3.2 +/- 0.9 vs 7.6 +/- 1.7 micro mol/L). Mean volume of irrigant used and operating time were similar in both groups. Volume deficit, decrease in protein, and hematocrit were less in GnRH than in the saline group. Blood ethanol levels, decrease in sodium, and irrigant deficit were significantly lower in GnRH group.

CONCLUSION

Pretreatment with GnRH analogs may prevent the adverse effects of estradiol on endometrial Na+, K+-ATPase and creates a protective mechanism against iatrogenic hyponatremia, which is more critical in women than men in case of absorption of irrigating fluid. Moreover, created hypoestrogenism may enhance Na+, K+-ATPase activity in brain as well as endometrium, thus decreasing women's susceptibility to hyponatremic complications and brain damage. Suppressed vasopressin levels may be protective against fluid absorption in GnRH analog-treated patients.

Psychiatric disorders after transurethral resection of the prostate

Three men in their 70s had long-term changes in mood and personality dating from immediately after transurethral prostatectomy. Focal abnormalities in the brain were not detected. The possibility of psychiatric as well as cardiovascular sequelae from this operation deserves investigation.

Trapping of electrolytes during fluid absorption in transurethral resection of the prostate

Absorption of irrigating fluid into the blood during transurethral resection of the prostate is associated with diffusion of sodium ions from the interstitial fluid space into the plasma. Some of this sodium is "trapped" and removed from the body in connection with bleeding and excretion of urine. The magnitude of this sodium loss was calculated over 10-min periods throughout 20 operations during which absorption of glycine solution occurred. The amount of trapped sodium increased with the amount of blood lost, a 1000-ml bleed correlating with a loss of 10 mmol of sodium. Two thirds was trapped with the plasma loss and one-third with the osmotic diuresis. This mechanism contributes to the absolute loss of sodium from the body. The total sodium loss, however, accounts for one third of the maximum hyponatraemia and is still dominated by the plasma-derived sodium excreted during the glycine-induced osmotic diuresis.

The degree of fluid absorption during hysteroscopic surgery in patients pretreated with goserelin

STUDY OBJECTIVE

To assess the effects of pretreatment with the gonadotropin-releasing hormone analog goserelin on fluid absorption in patients undergoing hysteroscopic endometrial ablation.

DESIGN

Prospective, randomized, placebo-controlled study.

SETTING

A university-based clinic.

PATIENTS

Thirteen women with dysfunctional uterine bleeding who were scheduled for electrosurgical hysteroscopic ablation.

INTERVENTIONS

Seven women were randomized to receive luteal phase goserelin 3.75 mg and six saline in the menstrual cycle approximately 10 weeks before surgery. Operative hysteroscopy was carried out with glycine 1.5% mixed with 2% alcohol medium under constant pressure as an irrigant. The amount of irrigant used, irrigant deficit, blood levels of albumin and ethanol, hematocrit, hemoglobin, changes in sodium levels, and central venous pressure were compared between the groups.

MEASUREMENTS AND MAIN RESULTS

All of the patients had an unsuccessful course of medical therapy for at least 3 months and a normal endometrial biopsy. The age, weight, and uterine size were similar between the groups. The mean volume of irrigant used and operating time were similar in both groups (4.18 +/- 0.2 vs 4.5 +/- 0.5 L, and 33.7 +/- 1.5 vs 37 +/- 2.1 min). Although operating time, volume deficit, decrease in protein level, and hematocrit were less in the goserelin than in the saline group, the differences were not statistically significant (p >0.05). The ethanol levels in blood, decrease in Na+, and irrigant deficit were significantly lower in the goserelin than in the saline group (17.4 +/- 3.8 vs 25.3 +/- 4.2 mg/ml, 6.7 +/- 1.2 vs 9.1 +/- 0.9 mEq/L, and 0.49 +/- 0.08 vs 0.66 +/- 0.05 L, respectively; p <0.05).

CONCLUSION

Based on these results we conclude that in women undergoing hysteroscopic endometrial ablation, pretreatment with goserelin may decrease the absorption of hysteroscopic medium, prevent fluid overload, and improve the outcome possibly by causing hypovascularity and decreased endometrial growth.

Changes in amino acids, ammonium, and coagulation factors after transcervical resection of the endometrium with a glycine solution used for uterine irrigation

OBJECTIVE

Transcervical resection of the endometrium with the use of 1.5% glycine for irrigation is associated with postoperative nausea in some patients. This could be because of hyponatremia or toxic effects of glycine and its metabolites. Moreover, 1.5% glycine is hypoosmolar, and hemolysis and fibrinolysis are possible. Changes in plasma factors related to these potential complications of transcervical resection of the endometrium were measured.

STUDY DESIGN

In 101 patients undergoing transcervical resection of the endometrium sodium, ammonium, and coagulation factors were measured preoperatively and postoperatively at intervals. In the initial 30 patients glycine and 28 other amino acids were measured at the same intervals. The results were correlated with the patients' clinical status and operative parameters.

RESULTS

Glycine and nine other amino acids and ammonia showed increased postoperative plasma levels; these changes were correlated with the absorption of the irrigating glycine solution and the development of hyponatremia. Minor activation of fibrinolysis and hemolysis was also seen.

CONCLUSION

Nausea after transcervical resection of the endometrium with 1.5% glycine for irrigation may be partly explained by toxic effects of glycine and its secondary metabolites in addition to the effects of water intoxication and hyponatremia. Minor, clinically insignificant changes in the coagulation system may also occur. Studies on alternatives to glycine for creation of near-isotonic irrigating solutions are encouraged.

Eye symptoms, visual evoked potentials and EEG during intravenous infusion of glycine

Disturbance of vision is a complication that may occur from absorption of the glycine solution used to irrigate the bladder during transurethral operations. We examined for a possible dose-response relationship between glycine dose, eye symptoms and neurophysiological changes after repeated intermittent intravenous infusions of 4.4 g of glycine for up to 22 g over 1 h in 10 male volunteers. The serum glycine concentration increased from 230 +/- 75 to 5,232 +/- 1,088 mumol/l (mean +/- s.d.) during the infusions. We found an increase in diastolic arterial pressure but no significant changes in systolic pressure, heart rate or mental status. Five of the volunteers developed blurring of vision which lasted for 10-30 min. The visual evoked potentials (VEP) of these subjects showed an increase of the P100 and N70 latencies which started after no more than 4.4 g of glycine had been administered. The amplitude of the VEP was preserved and the main frequency of the EEG did not change, indicating that VEP changes were not due to cortical dysfunction. There was no dose-response relationship between glycine infusion and eye symptoms but a sub-group of volunteers responded with both visual disturbances and VEP changes.

Glycine-induced hyponatremia in the rat: a model of post-prostatectomy syndrome

Post-prostatectomy syndrome (PPS) is characterized by hyponatremia after absorption of glycine irrigant. To study the pathogenesis of this syndrome, adult male rats with ligated ureters were infused over 15 minutes with 7.5 ml/100 g body weight of isosmotic glycine (N = 9) or mannitol (N = 9) and were compared to non-infused, ureter-ligated controls (N = 9). Immediately post-infusion, plasma sodium had decreased similarly in glycine- and mannitol-infused animals (111 +/- 2 vs. 106 +/- 1 mmol/liter), but plasma osmolality remained at control levels in both groups (285 +/- 1 vs. 288 +/- 1 mOsm/kg). Two hours post-infusion, hyponatremia was stable in the mannitol group (108 +/- 1 mmol/liter), but in the glycine group plasma sodium increased significantly (to 120 +/- 1 mmol/liter). Plasma osmolality two hours post-infusion was maintained in both the glycine (287 +/- 2) and mannitol (292 +/- 2) groups. Brain water in glycine-infused animals (3.90 +/- 0.01 liter/kg dry wt) was not significantly different from the mannitol-infused group (3.85 +/- 0.01) and only 1.8% higher than non-infused controls (3.83 +/- 0.02). Brain tissue glycine did not differ between the three groups. In contrast, muscle water two hours post-infusion in the glycine group was 6% higher than mannitol-infused and 13% higher than non-infused animals. Muscle glycine content in the glycine group (67 +/- 4 mM/kg dry tissue) was increased when compared to both mannitol-infused (25 +/- 1) and non-infused (20 +/- 1) groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Postoperative cerebral oedema after transcervical endometrial resection and uterine irrigation with 1.5% glycine

Absorption of irrigating solution during transcervical resection of endometrium can cause dilutional hyponatraemia, nausea, and cerebral oedema. We studied 6 patients who absorbed more than 1500 mL of 1.5% glycine, and 14 patients who absorbed less. Cerebral oedema was diagnosed by blinded, paired comparison of computed tomography (CT) scans 3-6 hours and 3-6 days after operation. The absorbed volume of irrigating glycine solution was correlated with peroperative decrease in serum sodium. 10 patients who absorbed 500 mL of glycine or more had postoperative nausea, with cerebral oedema suspected in 9. None of the 10 patients who absorbed less than 500 mL had nausea; changes on CT scan suggestive of cerebral odema were found in 1. 8 patients who absorbed 1000 mL or more had a decrease in serum sodium of 10 mmol/L or more, nausea, and cerebral oedema on CT scan. Cerebral oedema may contribute to the development of postoperative nausea in patients undergoing transcervical surgery who absorb more than 500 mL of 1.5% glycine irrigating solution.

Monitoring of body weight during transurethral resection of the prostate: preliminary report

The fear of vascular overload by irrigant during transurethral resection of the prostate is a reason for an incomplete resection. With continuous measurement of the patient's body weight and, thus, body water, irrigant entrance is immediately identified. We present a scale of proved accuracy and reliability, allowing more effective resection while eliminating the possibility of TUR syndrome.

Electroencephalographic changes from hyponatremia during transurethral resection of the prostate

A patient undergoing transurethral resection of the prostate suffered hyponatremia during the perioperative period. Electroencephalography demonstrated diffuse slowing although the patient was not clinically encephalopathic. The serum sodium level may indicate a trend toward development of the transurethral resection syndrome but the sodium level does not necessarily parallel metabolic changes in brain tissue. Consequently, electroencephalography may aid in the early diagnosis and treatment of encephalopathy during the early phases of the transurethral resection syndrome.

[Prostate transurethral resection syndrome]

The "transurethral resection of prostate" syndrome (TURPS) is the clinical manifestation of the resorption into the patient's body of a large amount of glycocolle-containing irrigating fluid used for this procedure. The full clinical picture, which is seldom seen, consists of dyspnoea, nausea, arterial hypertension, an increased central venous pressure, cerebral oedema, cardiogenic shock and renal failure. Improved surgical techniques, as well as incomplete and atypical forms of the syndrome could explain this low incidence. Absorption into the blood stream may be rapid, by way of the prostatic venous plexi, or slower, from the spaces around the prostate and under the peritoneum. The present-day pathophysiological theory explains this syndrome by an acute hyponatraemia, sometimes dissociated from the hypoosmolality, the toxicity of glycocolle, and the neurological effects of hyperammonemia. Acute hyponatraemia, with blood sodium concentrations below 115 to 120 mmol.l-1, should be considered as potentially serious. The different mechanisms involved may act alone or together, thus explaining that the minor forms of the syndrome mostly consist of a neurological picture. The emergency treatment depends on the natraemia. It includes diuretics and progressive reloading of the patient with sodium in case of severe hyponatraemia with seizures. The best prevention is a correct surgical indication and technique. The resection should not last for more than 90 to 120 min. The major problem remains the early diagnosis of TURPS. Carrying out this surgery under regional anaesthesia is helpful for this purpose, but, in the near future, the best means might be the monitoring of expired ethanol concentrations.

Absorption of irrigating fluid during transurethral prostatic resection as measured by ethanol, radioisotopes, and regular-interval monitoring

Ethanol monitoring is a novel noninvasive method for immediate detection of absorption of irrigating fluid during transurethral prostatic resection. Its accuracy was evaluated during thirteen resections using 5% mannitol +2% ethanol as the irrigating fluid. The ethanol concentration in the expired breath correlated strongly with the degree of absorption of intravascular irrigating fluid as determined by a radioisotope technique, and fluid volume measurements, and with the changes in the serum sodium concentration. Extravascular absorption of the irrigating fluid resulted in prolonged elevation of the ethanol concentration and gave smaller changes in the serum sodium concentration.

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.

The transurethral resection syndrome

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.

Visual evoked potentials and visual acuity after transurethral resection of the prostate

Changes in visual evoked potentials, visual acuity, blood ammonia levels and serum electrolytes (Na+ and K+) after transurethral resection of the prostate using glycine as an irrigating fluid performed under subarachnoid block were studied in 12 patients, in the pre-operative and immediate postoperative periods. Visual evoked potentials (p100 latency), recorded by shift of a checkerboard pattern, increased significantly from a pre-operative value of mean (SEM) 101.18 (1.63) msec in the right eye, and 102.5 (1.47) msec in the left eye to 108.91 (1.8) msec (p less than 0.01) and 108.08 (2.53) msec (p less than 0.01) respectively in the postoperative phase. There were no changes in visual acuity as assessed by a Snellen's chart, blood ammonia levels and serum electrolyte concentrations. The amount of glycine used intra-operatively for irrigation ranged from 3 to 31 litres.

Monitoring of irrigating fluid absorption during transurethral prostatectomy. A study in anaesthetised patients using a 1% ethanol tag solution

A simple, reliable method to detect absorption of irrigating fluid during transurethral prostatectomy is to tag irrigating fluids with 1% ethanol and monitor expired breath ethanol concentrations. This method correlated well (n = 0.79) with other existing methods of absorption monitoring in 20 anaesthetised patients. Ethanol (1%) tagging does not alter the optical quality of the irrigating fluid and is harmless to the patient. The technique is non-invasive, repeatable, cheap and gives instant results. It can be used in anaesthetised or awake patients and can detect absorption of as little as 100-150 ml in any 10-minute period.

The TURP syndrome

This article discusses the presentation, aetiology, treatment and prevention of central nervous system disturbances after transurethral resection of the prostate. Nausea and vomiting, visual symptoms, and altered states of consciousness have been reported as complications due to intravascular absorption of irrigating fluid. Hypotonicity after absorption of the irrigating fluid causes cerebral oedema. Hyperglycinaemia may cause visual disturbances and hyperammonaemia may cause delayed coma.

Prevention of TUR syndrome by detection of trace ethanol in the expired breath

Previous studies suggest that severe symptoms of the 'TUR syndrome' occur from transurethral prostatic resection only when the volume of irrigant absorbed exceeds 2000 ml. An ethanol-containing irrigating fluid was used in this study of 100 transurethral resections so that the irrigant absorption could be monitored by measuring ethanol in expired air. Fluid absorption was found in 41 patients, and in nine of them the volume of irrigant absorbed exceeded 1000 ml. Four of these operations were terminated promptly when the ethanol monitoring indicated rapid massive absorption that threatened to exceed 2000 ml. There were few and only mild adverse effects of the irrigant by following this regimen. It is concluded that ethanol monitoring makes it possible to prevent the TUR syndrome by selective termination of those operations in which large amounts of irrigant is absorbed.

Video transurethral resection. Report of 200 cases

Two hundred transurethral resections of the prostate (TURPs) were performed using a controlled continuous flow (CCF) resectoscope attached to a video camera by direct-beam coupler. Standing comfortably, the surgeon used a video monitor as the source of judgment for manipulating the loop. Data obtained were statistically similar to those obtained from 400 previous resections using the same resectoscope by the conventional viewing method. TURP can be performed safely, more efficiently and more comfortably with the CCF video technique.

Furosemide-induced disturbances of renal function in patients undergoing TURP

Furosemide remains the drug of choice for patients with the transurethral resection syndrome. Furosemide is often used intraoperatively to treat patients suspected of having excessive irrigant absorption. To examine the efficacy of such therapy, a randomized study was performed in which furosemide was administered to patients undergoing routine transurethral resection of the prostate (TURP) to determine the effect of furosemide on electrolyte and fluid volume conservation in these patients. Seven patients treated with furosemide on completion of TURP had a statistically significant delayed drop in serum sodium values after normal initial values (139 mEq/L to 134 mEq/L). Seven untreated control patients did not have a similar drop in sodium values, and the difference between groups was significant. We suggest that furosemide be used with caution in patients undergoing routine TURP, and when given it should be accompanied by the infusion of an isotonic balanced salt solution.

Isotonic hyponatremia following transurethral prostate resection

The proper treatment of hyponatremia during transurethral resection of the prostate continues to be controversial. Two cases of isotonic hyponatremia are reported here, and the literature regarding the incidence and treatment of hyponatremia during transurethral resection of the prostate is reviewed. In each case, the patient developed neurologic changes during complicated transurethral prostate resection. Despite the rapid decrease in the serum sodium concentration, serum osmolality remained normal due to the resorption of the bladder irrigant glycine. Therefore, etiologies other than cerebral edema are postulated as the cause of the neurologic manifestations. Also, the role of the osmolar gap in directing appropriate therapy is emphasized in an effort to avoid unnecessary use of hypertonic saline. Finally, an appropriate differential diagnosis of the neurologic changes seen during the transurethral resection of the prostate syndrome is discussed.

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.

Consequences of fluid absorption during transurethral resection of the prostate using distilled water or glycine 1.5 per cent

This prospective and randomized study compared the consequences of two irrigating fluids, distilled water and glycine for transurethral prostatectomy. Forty-nine consecutive unselected patients undergoing transurethral resection of the prostate with spinal anaesthesia were investigated. The irrigating fluid was either distilled water (group A, 24 patients) or glycine 1.5 per cent (group B, 25 patients). The absorption of irrigating fluid was measured, all surgical events and any clinical signs of TURP syndrome during and after surgery were recorded. Early signs of TURP syndrome were observed in one patient in group A and in four in group B without further consequence. From all the biological variables, only plasma protein concentration, haematocrit, free plasma haemoglobin and free bilirubin concentrations were found to have changed. Plasma protein concentration and haematocrit decreased significantly during and after surgery in the two groups. Free plasma haemoglobin increased significantly with time: a significantly higher concentration was observed in group A than group B. Free bilirubin concentration increased with time in the two groups and was statistically greater in group A. With the two irrigating fluids, we observed a significant amount of haemolysis and haemodilution without clinical consequences. A low irrigating fluid pressure, a short resection time, and the use of spinal anaesthesia seems to us to be essential. Close observation of patients following transurethral prostatectomy is needed but the choice of the irrigating fluid does not seem to be important.

The physiologic basis of the TUR syndrome

To better assess the role of hyperammonemia versus hypoosmolarity versus hyponatremia in the TUR syndrome, we developed a rat model. Sprague-Dawley female rats received an intraperitoneal injection (250 cc/kg body weight) of either 1.5% glycine, 2.0% glycine, 2.0% glycine plus 1.5% mannitol, 3.0% mannitol, 5.0% mannitol, or 2.0% glycine plus 0.25% saline. Arterial blood samples were obtained prior to injection, at 2, 8, 16, and 24 hr and analyzed for osmolarity, sodium, and ammonia. Those animals receiving 2.0% glycine, 2.0% glycine plus 1.5% mannitol, and 5.0% mannitol all died within 24 hr with lethargy, convulsions, and coma. Hyponatremia developed in all animals; death, however, occurred only when the sodium concentration declined to 90-95 meq/dl. Mannitol maintained serum osmolarity but did not prevent coma and death. Including 0.25% saline in the initial injection, or an iv injection of 5.0% saline delayed 8 hr achieved 100% survival. Ammonia concentrations increased 15-fold by 8 hr in groups receiving 2.0% glycine; it rapidly decreased to near normal by 24 hr. Decreasing the rise in ammonia by 50% with iv arginine had no effect on survival. Our results suggest that hyponatremia rather than hyperammonemia or hypoosmolarity accounts for the major morbidity and mortality secondary to the TUR syndrome.

Severe hyponatremia without severe hypoosmolality following transurethral resection of the prostate (TURP) in end-stage renal disease

A 55-year-old man on chronic hemodialysis underwent a transurethral resection of the prostate (TURP), during which 3% sorbitol solution was used for urethral irrigation. Following the procedure, he developed symptomatic hyponatremia (serum sodium, 106 mEq/L), but had only mild hypoosmolality (serum osmolality, 269 mosm/kg). The "osmolal gap" was 47 mosm/kg, probably from sorbitol absorbed systemically during the TURP. Hemodialysis raised the serum sodium to 118 mEq/L, and the serum osmolality to 284 mosm/kg, while lowering the osmolal gap to 26 mosm/kg. The presence of severe hyponatremia with only modest hypoosmolality may occur in patients with renal failure following the systemic absorption of hypotonic fluids containing solutes such as sorbitol and mannitol. Hemodialysis offers the advantages of correcting the hyponatremia while removing the unmeasured solute, thus preventing rapid increases in the serum osmolality.