Transurethral Resection of the Prostate Syndrome (TURP Syndrome)

The presentation, in the order it arrives - Nausea, headache, and dizziness come first. It progresses to dyspnea, confusion, hypertension, and bradycardia — that hypertension-with-bradycardia pairing is the tell, and it is the opposite of what surgical blood loss looks like. Left alone it goes on to seizures and cardiac arrest.

Regional anesthesia is a monitor, not a shield - A spinal keeps the patient awake, so the early mental status change and nausea present as symptoms instead of being masked by general anesthesia. Many texts describe spinal as protective, but the outcome data comparing spinal with general are thin. The real value is early detection.

Get the fluid deficit, not an eyeball estimate - Blood loss is genuinely impossible to assess through that volume of irrigation. Ask the circulator to calculate inputs and outputs and give you the deficit. The risk of neurologic symptoms climbs sharply once absorption exceeds 1000 mL, and one study put the threshold rate at 200 to 300 mL per 10 minutes.

The sodium drop tracks the volume absorbed - In men, absorbing 1000 mL of glycine irrigant drops the sodium 6 to 8 mEq/L and 3000 mL drops it about 20 mEq/L. Women reach the same drop on less — roughly 10 mEq/L per 1000 mL — because of lower lean body mass and total body water, which matters when the same irrigants are used for hysteroscopy.

Glycine causes its own trouble beyond the sodium - Glycine is an inhibitory transmitter in the spinal cord, brainstem, and retina, and it produces transient visual changes — blurred vision, reduced acuity, and even frank blindness — that the sodium alone does not explain. It is metabolized to ammonia, serine, and glyoxylate; in two patients who became comatose after TURP the mental status correlated better with the serum ammonia than the sodium. Send an ammonia when a patient stays obtunded with a corrected sodium.

Sorbitol and mannitol behave differently - Sorbitol gives a similar picture minus the visual symptoms. Mannitol is near isotonic, is not metabolized, and stays extracellular, so symptoms are markedly less prominent — but it drives an osmotic diuresis. Glycine has the worst symptom profile and the poorer outcomes of the three.

Osmolality will mislead you - Because the absorbed glycine or sorbitol is itself an osmole, the measured osmolality falls far less than the sodium does. In one series of 100 TURP patients the mean sodium fell 17.7 mEq/L, which should have dropped osmolality about 35 mOsm/kg; it fell only 11.4. Calculate the osmolal gap — normally under 5 to 10 mOsm/kg, it can hit 30 to 60 immediately after resection. A near-normal osmolality alongside a sodium of 110 does not mean the patient is fine.

Hypertonic saline when symptomatic with a low osmolality - For a symptomatic patient with marked hyponatremia and genuinely reduced osmolality or cerebral edema, 100 mL of 3% saline as a bolus delivers 51 mEq of sodium and should raise the sodium 2 to 3 mEq/L; repeat once or twice at 10-minute intervals if neurologic symptoms have not improved. When the sodium is low but osmolality is normal or near normal, above roughly 270 mOsm/kg, hypertonic saline should probably not be used and hemodialysis is the safer route — it also clears the irrigant solute and its metabolites.

Rapid correction is comparatively safe here - The hyponatremia is hours old, so the cerebral adaptations that make chronic hyponatremia vulnerable to osmotic demyelination have not had time to occur. Still stay under 12 mEq/L in the first 24 hours, and under 8 to 10 mEq/L if the patient presents more than 48 hours after the procedure.

Asymptomatic does not need treating - A sodium drop of 5 mEq/L or less with no symptoms, or a patient still anesthetized in whom symptoms cannot be assessed, needs nothing if kidney function is intact — the excess water is excreted and the solute is metabolized. Give a loop diuretic only for actual pulmonary congestion; furosemide in a patient who is not volume overloaded reduces effective intravascular volume and can make things worse.

The hypotension comes after the irrigation stops - The osmotic natriuresis caused by glycine, mannitol, or sorbitol both prolongs the hyponatremia and contributes to hypovolemia and hypotension that typically develops 15 to 20 minutes after irrigant absorption has ended. Do not stand down when the scope comes out.

The nadir is often in PACU - Fluid that extravasates rather than intravasates lowers the sodium more slowly, and the sodium is usually lowest one to two hours after surgery. Recheck a sodium in recovery on anyone with a large deficit.

Other consequences of large-volume irrigation - Hypothermia and coagulopathy both follow from the volume itself. Watch the temperature on long resections and expect the bleeding picture to worsen with it.

Bipolar is not a free pass - Bipolar and laser systems allow isotonic saline or Ringer's lactate and have essentially eliminated procedure-related hyponatremia; a meta-analysis of monopolar versus bipolar TURP found bipolar eliminated the syndrome outright. Absorbing several liters of saline still expands the extracellular fluid, so dyspnea, pulmonary edema, blood pressure swings in either direction, and hyperchloremia remain on the table.

Same syndrome, other procedures - Transurethral resection of bladder tumors, hysteroscopic resection (particularly of fibroids), and percutaneous nephrolithotomy use the same nonconductive irrigants and produce the same problem.

Transurethral resection of the prostate syndrome (TURP syndrome) is what happens when irrigation fluid is absorbed through prostatic venous sinuses opened during resection. A monopolar resectoscope cannot be used with an electrolyte-containing irrigant because the current disperses, so nonconductive solutions are required: 1.5% glycine (most common), 3% sorbitol, or 5% mannitol. Glycine and sorbitol are hypoosmotic at 200 and 165 mOsm/kg against a normal serum osmolality of 280 to 296, so absorbing them produces dilutional hyponatremia on top of volume overload.

Absorption begins once irrigation pressure exceeds venous pressure, around 10 mmHg, and is greater during the second half of the case regardless of total operating time; perforation of the prostatic capsule lets fluid extravasate into the periprostatic space instead. Roughly 2% of men undergoing monopolar transurethral resection develop hyponatremia severe enough to cause confusion, nausea, and vomiting.