Transurethral resection of the prostate (TURP) is a common urologic procedure to help alleviate the urinary obstructive symptoms of benign prostatic hypertrophy (BPH) (1). This endoscopic procedure utilizes irrigation solution to aid with visibility; it distends structures and clears tissue debris and blood. However, the exposed prostate vasculature can absorb irrigant fluids, resulting in systemic absorption.
TURP syndrome is an iatrogenic constellation of signs and symptoms caused by volume overload, hyponatremia (serum sodium <125 mEq/L), and osmolality and solute aberrations. TURP syndrome can
Produce deleterious effects on central nervous, cardiovascular, metabolic, and renal systems.
Be potentially fatal if not recognized and treated appropriately.
The anesthetic plan for a TURP procedure may consist of either a general or neuraxial technique, while maintaining a high index of suspicion for TURP syndrome if signs and symptoms arise. Cardiac morbidity and mortality is equivocal when comparing general and neuraxial anesthesia.
Epidemiology
Incidence
0.78–1.4% of all TURP procedures
Alternative treatments for BPH have resulted in a decreased number of procedures and hence occurrence.
Morbidity
Varies depending on the severity of the syndrome
In general, patients with significant comorbidities are at a greater risk for morbidity associated with TURP Syndrome.
Mortality
Can reach up to 25% in severe TURP syndrome (defined as symptoms of TURP syndrome plus hyponatremia <120 mEq/L) (2).
Etiology/Risk Factors
Resection of the prostatic urethra and prostate gland nodule is completed using a resectoscope equipped with electrocautery capability. An irrigation solution is used to maintain visibility for the surgeon. Systemic absorption of the irrigant leads to TURP syndrome.
A variety of factors are associated with an increased risk of TURP syndrome
Position: Increased with Trendelenburg position, as gravity facilitates absorption.
Prostate size: Gland size >45 g; larger glands often increase vascular exposure to irrigation solutions
Procedure time: Gland resection time >90 minutes; longer procedure times increase exposure to irrigation solutions
Surgical hemostasis/visibility: Impaired visibility of the surgical field requires the use of more irrigation. Decreased visibility may also increase surgical times; this results in increased exposure time of irrigation solution to the open vasculature.
Irrigant fluid bag height: (controversial) There are reports that a fluid bag height >60 cm above the patient creates high irrigation pressures, which increases risk (2,3).
Physiology/Pathophysiology
The prostate is made up of four zones contained within one capsule. The gland has a rich vascular supply within and immediately adjacent to the gland.
Irrigation solution gains immediate access to the circulation via openings in the prostate capsule during resection procedures, or over time as irrigant solution is taken up from retroperitoneal and/or perivesicular spaces. Among other concerns, irrigation solutions are ideally transparent, nonhemolytic, isotonic, nonconductive, and inexpensive.
Glycine solution: Glycine itself may lead to hyperglycinemia, which is associated with encephalopathy, seizures, and visual disturbances. Glycine is known to increase NMDA receptor activity, which may then increase CNS excitation. Liver and kidney metabolism of intravascular glycine creates glycolic acid and ammonia, both of which are potentially toxic.
Cytal solution: Can create increased levels of fructose, which is poorly handled by those with liver dysfunction.
Physiologic saline, sorbitol, and mannitol have also been described for use in TURP.
Intravascular volume expansion: Large volumes of irrigant solution can be moved into the intravascular circulation; this is enhanced with large volume irrigation and lengthy procedures. This volume increase is poorly tolerated in patients with renal disease or poor left ventricular function (1,2).
Hyponatremia: Acute hyponatremia can develop due to the rapid uptake of irrigation solutions. These changes in serum sodium are poorly tolerated (especially by the CNS). Hyponatremia causes intracellular edema within neurons, which alters normal neuronal function. The relative decrease in serum sodium is important, but the symptomatic patient with a serum sodium <120 mEq/dL defines severe TURP Syndrome.
Hypoosmolality: Often associated with hyponatremia; acute hypoosmolality causes changes in neuronal transmembrane potentials. Such changes can lead to CNS abnormalities, due to cerebral edema and altered neuronal transmission.
Preventative Measures
Avoid the steep Trendelenburg position
Surgical efficiency promotes shorter procedure times and less volume of irrigant solution used.
Maintain the irrigant solution bag at a height <60 cm above the level of the patient.
If concern for TURP syndrome arises, discussion with the surgeon should occur. Consideration should be given to checking serum sodium, which would assist in early diagnosis of hyponatremia.
Some surgeons may ask for prophylactic furosemide; this should be done with careful consideration of volume status and serum sodium; attention must be paid to furosemide side effects (hypotension, electrolyte imbalances).
Consider other BPH treatment options in patients with very large prostate glands and significant comorbidities.
Spinal or epidural anesthesia may be preferable to general anesthesia as TURP syndrome symptoms may be identified earlier in responsive patients.
Minimize maintenance fluids and boluses. Consider low-dose phenylephrine infusion preceding a neuraxial technique to avoid hypotension, in lieu of fluid boluses.
Newer TURP procedures (e.g., TURP with GreenLight laser) allow for use of saline irrigation, which may reduce incidence of TURP syndrome.
Diagnosis⬆⬇
TURP Syndrome is a clinical diagnosis based on identification of signs and symptoms, which are often vague. A high index of suspicion on the part of the anaesthetist and urologist is thus essential. Signs, symptoms, and laboratory findings include
Neurologic: Agitation or lethargy, confusion and restlessness, which may progress to seizures, paralysis, and coma. Nausea and vomiting may be seen, as may visual disturbances.
Cardiovascular: Hypertension and bradycardia or dysrhythmia may be seen as early findings. Respiratory distress, hypotension, and frank shock may follow.
Metabolic/renal: Hyponatremia, hypoosmolality, hyperglycinemia, hyperammonemia, and acute renal failure may be noted on laboratory evaluation.
Severe TURP syndrome is commonly defined as a symptomatic patient with a serum sodium <120 mEq/L.
Differential Diagnosis
Cerebrovascular accident
Acute renal failure
Postoperative delirium
Acute coronary syndrome or cardiogenic shock
Treatment⬆⬇
Mild symptoms: First symptoms are often nausea and face/neck paresthesias; the first signs may be bradycardia and decreased BP. Initial treatment should be directed at symptoms (e.g., treat nausea with antiemetics). Consider close monitoring and review of laboratory data.
Severe symptoms
Hypertension and/or bradycardia may require invasive monitoring (arterial line or central line), atropine, or inotropes. If believed to be due to hypervolemia, volume removal may be necessary.
Furosemide treatment, beginning at a low dose (20 mg IV), helps reduce free water volume; however its use is suggested only in the setting of hypervolemia, as hyponatremia may worsen. Additional doses can be titrated as needed.
Hemodialysis for volume removal has a role as well, especially in patients with ESRD that are unable to create urine or clear toxins (like glycine or ammonia).
Severe hyponatremia may require hypertonic saline administration, with the goal to slowly raise the serum sodium over several hours. It is recommended that the serum sodium be increased at a rate of ~0.5 mEq/hour. If corrected too fast, central pontine myelinolysis (CPM) may result. CPM occurs with rapid neuronal cellular volume decrease secondary to rapid correction of hyponatremia; symptoms occur 2–6 days after sodium correction, and can include dysphagia, dysarthria, muscle weakness/paralysis, and obtundation; may be irreversible.
Seizures may be halted with barbiturates, benzodiazepines, or propofol.
The use of barbiturates or propofol may impair ventilation and airway protection
Serum magnesium levels may also be altered during TURP syndrome and a magnesium (Mg2+) infusion trial (an NMDA antagonist) may stop seizures, especially in the setting of hyperglycinemia (1,2). Mg2+ can be given as 2 g over 10 minutes while watching for toxicity (muscle weakness, mental status changes, pulmonary edema).
Cardiovascular collapse requires ACLS with mechanical ventilation as necessary.
Consider consultation of appropriate medical specialists (e.g., nephrologists for fluid and electrolyte evaluation, neurologists for neurologic status evaluation).
Follow-Up⬆⬇
ICU care as required by patient status and monitoring needs.
References⬆⬇
GravensteinD.Transuretheral resection of the prostate (TURP) syndrome: A review of the pathophysiology and management. Anesth Analg. 1997;84:438–446.
HawaryA, MukhtarK, SinclairA, et al.Transuretheral resection of the prostate syndrome: Almost gone but not forgotten. J Endourol. 2009;23:2013–2020.
MalhotraV.Transurethral resection of the prostate. Anesthesiol Clin North Am. 2000;18:883–897.
Additional Reading⬆⬇
AdrogueHJ, MadiasNE.Hyponatremia. N Eng J Med. 2000;342:1581–1589.
See Also (Topic, Algorithm, Electronic Media Element)
997.5 Urinary complications, not elsewhere classified
ICD10
E87.1 Hypo-osmolality and hyponatremia
N99.89 Oth postprocedural complications and disorders of GU sys
Clinical Pearls⬆⬇
A high index of suspicion is crucial so that the condition can be treated in its earliest stage. A high level of monitoring and supportive care should be immediately instituted. If untreated, it may progress to death.
Signs and symptoms of TURP syndrome can be vague and seemingly unrelated. The pathophysiologic basis is