Anest turp

Servizio di Anestesia e Rianimazione Ospedale di Faenza(RA)

Anesthesia for TURP

Claudio Melloni



Anesthesia for Turp is not always routine

Major KO: 2.5 - 20% of patients perioperative mortality rate :0.5 - 6%, Holtgrewe HL, Valk VVL. Factors influencing the mortalityand morbidity

of transurethral prostatectomy: a study of 2,015 cases.J.Urol 1962; 87: 450‑9.

Roos, N. P., Wennberg, J. E., Malenka, D. J. et al: Mortality and,.re‑operation after open and transurethral resection of the prostate for benign prostatic hyperplasia. N Engl J Med, 320: 1120,1989

Malenka, D. J., Roos, N., Fisher, E. S. et al: Further study of the increased risk of mortality following transurethral resection of the prostate: a chart‑based analysis. J Urol, 144: 224, 19

Seagroatt, V.: Mortality after prostatectomy: selection and surgical approach. Lancet, 346: 1521, 1995


Risk factors in anesthesia for TURP

Patients,their intrinsic risk factors and anesthesia related risks

Surgical Procedure;its complication,some peculiar to the technique used;

Utilization of irrigating fluids.


Turp Syndrome

Cardiovascular;hypotension,hypertension,dysrythmias,shock,pulmonary edema,cardiac arrest….

Respiratory;tight feeeling in the chest or throat ,shortness of breath,hyperventilation,dyspnea,pulmonary edema….

Cerebral;dizziness,mental confusion, and lethargy lapsing into coma,headaches,nausea, ,restlessness ,retching,blindness,twitches and seizures.;

bacteremia…...


Late Turp syndrome

4 - 24 hours later Some of these cases could be ascribed to instrumental perforation of the

prostatic capsule ( and more rarely of the bladder) fluid deposited in a pool in the retroperitoneal space the fluid may comprime the caval veins and diffuse through the peritoneal

membrane again creating flows according the Starling laws;electrolytes entering the pool of fluid and solutes contributing to plasma volume decrease as the solute travel in the opposite direction,i.e.toward the cell,where they are metabolized or accumulate

In these case moderate hyponatremia and hypoosmolality develop with a time delay ,some hours following the operation.Clinically there is a tendency toward an

increased incidence of abdominal pain,bradycardia and hypotension


TURP symptoms associated with 2000 or + ml glycine absorption(Hahn et al.J.Ethanol monitoring of the

TURS.Clin.Anesth.1996;8:652-655)

Intraop symptoms freq(20-

60%):BP ,HR,BP common(10-

20%):prickling skin,nausea,tiredness.uneasiness

rare (<10%):blurred vision,chest pain,confusion

Postop symptoms confusion,BP,nausea,tr

ansient anuria bradyc,diarrhea,freezin

g,vomiting

blurred vision,depressed consciousness,abdominal pain


Ideal requirements of an Irrigating solution

Purpose:give the surgeon a clear view of the operating field by removing blood and pieces of resected tissues.

Electrolyte free to allow cutting with a resectoscope Isotonicelectrically inertnon toxic,clear transparenteasy to sterilize and handlenot too expensive….


Irrigating fluids

H2O distilled glycine 1.2-1.5% mannitol 3% mannitol –sorbitol(2.7-0.54 %

respectively)mixtures.


Toxicity of irrigating fluidsglycine :

significant cardiac and retinal toxicity may cause hyperammonemia because its

metabolites overload the urea synthesis cycle

glucose may cause severe hyperglycemia

mannitol and sorbitol may cause lactic acidosis and hyerglycemia due to shifts in the glycolysis pathways


Volume absorption

the intravesical pressure (governed by the height of the irrigation bag above the prostatic sinuses)

the number of prostatic sinuses opened retroperitoneal and paravescical spaces,even in

absence of surgical perforation– length of the procedure,– experience of the surgeon(or inexperience)– difficult resections



entrainment of the solution

Circulatory overload haemodilution hypotonia and hypoosmolality …………. haemolysis,shock ,renal failure…….. acidosis hypoperfusion shock circulatory

failure hypoxemia


Vol.absorbed= ((preop serum Na/postop serum NA)*ECF in KG))-ECF in KG.

P es,if a preop sodium was 140 and postop is 110,the calculation yelds for an estimate of EC as 30% of body weight for a 70 kg man=21 kg:

1)140/110=1,2 2)1,2*21=26,6 3)26,6-21=5.6,volume gain in KG(or lt).


Hypotension-hypertension...

Perioperative hypotension during TURP is sometimes preceded by hypertension . Profound hyponatremia by itself does not explain the hypotension;however, hyponatremia with hypertension may lead to net water flux along osmotic and hydrostatic pressure gradients out of the intravascular space and into the lungs, which triggers pulmonary edema and hypovolemic shock . This concept is consistent with the findings of Hahn(17) who hypothesized that the absorption of fluids derives from two sources;one from direct absorption into the circulation(early phase?)and the second form interstitial accumulation ,both from periprostatic and retoperitoneal spaces and from fluid shifts along physiological gradients,according to Starling equation?????..................The excretion of urine is rapidly increased by all irrigating fluids ,especially mannitol (18) resulting in a osmotic diuresis and hence a net loss of circulating volume,but the situation changes according to the volume administered ,since exretion of glycine is less thant that of mannitol or sorbitol,with a greater intracellular accumulation of glycine (19)(20).


Atallah et al.Does spinal anesthesia affect cerebral oxygenation during transurethral

prostatectomy?.Reg.Anesth.Pain med. 1998;23:115-8.

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basal after spi chri 30 chirend post30 post60 post120

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jug.bulb O2 sat

art-jug O2 diff

CPP

jug bulb O2 content


Atallah et al.Does spinal anesthesia affect cerebral oxygenation during transurethral

prostatectomy?.Reg.Anesth.Pain med. 1998;23:115-8.

CPP decrease and SjbO2 decrease,a-jbO2 increase:CBF decrease,CMRO2 unaffected:impaired cerebral oxygenation

patients with symptoms more affected by decrease in SjbO2


Biphasic absorption of fluids

H yp oosm ola lity

A P O ed em a H yp ovo lem ic sh ock

H 2 O in te rs t

B P

N A d iu res is

H 2 0 en tra in m en t

Atrial natriuretic factor

glycine

Ca++


Hypoosmolality > hyonatremia

In a series of 72 patients undergoing TURP, serum sodium concentration decreased by 10 to 54 mmol/L in 19 (26%), while osmolality changed in only two (3%): the 2 patients who had both hyponatremia (serum sodium concentration decreases of 27 and 30 mmol/L) and hypoosmolality (serum osmolality of 260 and 256 mmol/L) developed pulmonary edema and encephalopathy. The five patients in this series with the largest decreases in serum sodium concentration (by 34 to 54 mmol/L) had no changes in serum osmolality and no signs of TURP syndrome. (Desmond J. Serum osmolality and plasma electrolytes in patients who develop dilutional hyponatremia during transurethral resection. Can J Surg 1970; 13:116-21).

A review of a series of 2000 consecutive patients( Henderson DJ,Middleton RG.Coma from hyponatremia following transurethral resection of prostate.Urology 15;267-71,1980) revealed 14 coma cases potoperatively,with sodium levels 15-20 meq/lt below normal level:the coma was ,at that time , correctly,ascribed to water intoxication and associated surgical risk factors were identified,because in 9 of these cases the prostatic capsule was surgically violated or large venous sinuses were opened;all 14 patients eventually awoke without sequelae.


Blood loss Total blood loss after TURP is significantly correlated

with the prostatic tissue weight but when the tissue weight resected exceeds 35

gr,blood loss was in excess of the linear correlation(Smyth R, Cheng D, Asokumar B et al. Coagulopathies in patients after transurethral resection of the prostate: spinal versus general anaesthesia. Anesth Analg 1995; 81: 680‑5)


Smyth R, Cheng D, Asokumar B et al. Coagulopathies in patients after transurethral

resection of the prostate: spinal versus general anaesthesia. Anesth Analg 1995; 81: 680‑5

. There was no significant difference in measured coagulation variables (fibrinogen, factor V, plasminogen, antithrombin III, and FDP) between the spinal and GA groups, but there were significant decreases in postoperative fibrinogen and Factor V levels compared to preoperative values in both spinal and general anesthesia groups.

3 pts (6%) had increased FDP levels 1 h postop. The prostatic tissue weight and the surgical duration was significantly higher in these patients.

The authors concluded that perioperative blood loss in TURP patients is not affected by the anesthetic technique,but 6% of TURP patients developed subclinical intravascular coagulopathies which correlated with mass of resected prostate tissue.


Therapy of Turp syndrome

diuretics? Saline hypertonic saline? Inotropes/vasopressors(?) The most feared complication of correcting

hyponatremia is central pontine myelinolysis (CPM


Treatment of symptomatic hyponatremia

Safest treatment;symptomatic slow therapy ( <=0.7 mmolLt/h) , has been associated with a higher

morbidity and mortality than has rapid correction (=>1.0 mmol/lt/hr) Many reports suggesting that a 1.5- to 2.0-mmol /Lt/hr correction

rate is safe have failed to consider changes in osmolality. Several investigators have suggested that osmotic stress is probably greater when correcting chronic compared with acute hyponatremia

a prompt treatment with increases in the serum Na concentration not > 2 mmol/lt/hr;in general the correction dose not require doses > 100 ml/hr .


Hyperglycinemia

Incidence and severity of circulatory and nervous symptoms(nausea, vomiting, headache, malaise weakness,seizures, from blurred vision to complete blindness…) proportional to the amount of glycine absorbed:» serum glycine concentration threshold for symptomatic

visual impairment (>4000 mmol/L) and blindness (>13,734 mmol/L)


Glycine toxicity

Retina cardiomyocites kidney(Hyperoxaluria from metabolism into oxalate and glycolate)

hyperammoniemia


Treatment of hyperglycinemia

Mg? NMDA antagonists L-arginine


Olsson J, Nilsson A, Hahn RG. Symptoms of the transurethral resection syndrome using glycine as the

irrigant. J Urol 1995; 154: 123‑8

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glycine absorption

0-3001-2 lt>3 lt


Nilsson A,Olsson J,Hahn RG.Symptoms of the TURP syndrome using glycine as the irrigant.J

Urol 1995;154:123-128

glycine


Fluid absorption during TURP;influence of

operating time(Hahn RG, Ekengren J. Patterns of irrigating fluid absorption during transurethral resection of the prostate as indicated by

ethanol. I Urol 1993: 149: 502‑6

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op-time <= 60 min op time > 60 min

>2000

1001-2000

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Urine composition 90 min after i.v infusion of 15 ml/kg of irrigating fluids(10 healthy male

volunteers) Nilsson A, Randmaa 1, Hahn RG. Haemodynamic effects of

irrigating fluids studied by Doppler ultrasonography in volunteers. Br I Urol 1996; 77: 541‑6

Osmotic gap represents negatively

charged ions not measured


Urinary excretion of sodium during and after iv

infusion of glycine solution in sheep and humans. (Hahn RG Trapping of electrolytes during fluid absorptionin transurethral resection of the

prostate. Scand j Urol Nephrol, in press)


Trepanier,CA,Lessard,MR,Brochu,J,Turcotte,G.Another feature of TURP syndrome:hyperglycemia

and lactic acidosis caused by massive absorption of sorbitol.Brit. J. Anaesth. 87;316-9:2001

hyperglycaemia and lactic acidosis


Gehring et al.Irrigation fluid absorption during TURP;spinal vs general anesthesia.AAS

1999;43:458-63. Blood ethanol

absorption rate Blood ethanol maximum levels

Blood ethanol area

under the curve Estimated volume of absorption(Hahn

nomogram)


Gehring et al.Irrigation fluid absorption during TURP;spinal vs general

anesthesia.AAS 1999;43:458-63.

Extent of irrigating fluid absorption significantly higher in absorption afflicted patients undergoing spinal anesthesia….;lower CVP may be the cause


Why regional anesth.is to be preferred

It allows the appearance of the full clinical manifestation of symptoms » (under GA only rise and fall in blood pressure ,respiratory

arrest and severe bradycardia,with a variety of ECG modifications)

possibility of early detection of TUR syndrome


significant fluid absorption has taken place when ethanol concentration in plasma exceeeds 0.1/1000.Plasma and exhaled ethanol demonstrated a linear correlation ,while plasma ethanol correlated inversely with plasma sodium .The measurements were consistent both in patients under spinal and ga ,undergoing mechanical ventilation;but ethanol levels were not predictive of sodium concentrations so that the authors recommended additional separate electrolytes determinations whenever exhaled ethanol exceeds 0.2/1000.


Recommendations for anesth.

continuous warming of i.v. fluids (warming of the patient) lab monit :Hb,Na ,glyc ;coag in susp.cases PVC? NIBP,SaO2,etcO2,ethanol EGA,lactate consciousness be vigilant


Recommendations for surgery

Minimize absorption» Limiting the height of the irrigation bag to 40 cm above the prostate» use continuous irrigating resectoscopes» use suprapubic trocar drainage

keep intravesical pressure < 15 cm H2O continuous warming of irrigating fluid Resection time < 1 hour leave a rim of tissue on the capsule until near the end of the

procedure New techniques….


Difficulties for the anesthesiologist who wants to introduce a method for monitoring of fluid

absorption in their hospital

Urologist often regard fluid absorption as a complication indicating poor operative skills» address this point cautiously because this determines the

success of the project... many clinicians believe TUR syndrome is too rare to

warrant routine monitoring:» prepare by reading some prospective studies where the incidence

of the mild form of the syndrome have actually been studied….–Hahn,RG,Editorial.The transurethral resection syndrome-not yet a

finished story.Reg.Anesth.Pain Med.1998;23:115-118.Professor of Anesthesiology,Karolinska Institute Stockholm,Sweden

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Anest turp

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