Post-TURP Headache: Causes and Pathophysiology
Post-TURP headache is primarily caused by TURP syndrome, a dilutional hyponatremia resulting from systemic absorption of hypotonic irrigating fluid during the procedure, which leads to cerebral edema and neurological symptoms including headache. 1
Primary Mechanism: TURP Syndrome
TURP syndrome occurs when irrigant solution is absorbed into the bloodstream through opened prostatic venous sinuses during resection. 1 This unique complication manifests as:
- Dilutional hyponatremia - the hallmark feature that drives cerebral symptoms 1, 2
- Cerebral edema - resulting from osmotic fluid shifts into brain tissue due to hyponatremia 3
- Hypo-osmolality - contributing to intracranial pressure elevation 3
The incidence of TURP syndrome is less than 1% with modern techniques, but when it occurs, headache is a prominent early neurological manifestation. 4, 2
Temporal Dynamics of Fluid Absorption
The pathophysiology evolves in distinct phases:
- First 20 minutes: Hypervolemia develops with marked electrolyte diffusion from interstitial space to plasma, causing elevated central venous pressure 5
- After 20 minutes: Fluid shifts from plasma to interstitial space with minimal sodium diffusion, promoting hypovolemia and worsening cerebral edema 5
This biphasic response explains why headache and other neurological symptoms may worsen even after the procedure ends.
Irrigant-Specific Toxicity
Glycine 1.5% solution carries the highest risk for TURP syndrome and associated headache. 6 When absorbed systemically, glycine causes:
- Hyperglycinemia - direct neurotoxic effects 3
- Hyperammonemia - from glycine metabolism, contributing to encephalopathy 3
- More severe hyponatremia - compared to other irrigants 6
In a randomized trial of 360 patients, all 17 cases of TURP syndrome occurred exclusively in the glycine group, with none in the glucose 5% or saline 0.9% groups. 6
Clinical Presentation
Monitor for these cardinal signs of TURP syndrome that accompany headache:
- Confusion and altered mental status 4
- Nausea and vomiting 4, 7
- Visual disturbances including transient blindness 4, 3
- Hypertension (early phase) or hypotension (late phase) 5
- Bradycardia 3
Severe cases can progress to coma, convulsions, and cardiovascular collapse. 3, 8
Risk Factors for Development
Prolonged resection time is the most critical modifiable risk factor:
- Resection time >90 minutes dramatically increases absorption risk 4
- Larger prostate volumes require longer operative times and increase bleeding, facilitating irrigant absorption 2
- Higher irrigation pressures and extensive venous sinus opening promote fluid entry 5
Biochemical Abnormalities
Laboratory findings that correlate with headache severity include:
- Serum sodium <120 mmol/L - severe cases may drop to 90 mmol/L 8
- Rapid sodium decline - drops of 14 mEq/L or more within hours 7
- Elevated glycine levels - when glycine irrigant is used 6, 3
- Hypocalcemia - contributing to neuromuscular irritability 3
Prevention Strategies
Limit resection time to under 90 minutes and use bipolar TURP when available to minimize irrigant absorption. 4 Additional preventive measures include:
- Use isotonic saline 0.9% or glucose 5% instead of glycine 1.5% 6
- Maintain adequate hemostasis throughout resection to minimize venous sinus opening 4
- Monitor fluid balance and vital signs continuously during the procedure 9, 4
Management Approach
When post-TURP headache with suspected TURP syndrome develops:
- Immediately check serum sodium and osmolality 3
- Slowly correct hyponatremia - avoid rapid correction to prevent osmotic demyelination 7
- Consider hemodialysis for severe cases with profound hyponatremia (<90 mmol/L), coma, or cardiovascular instability 3
- Fluid restriction for mild-moderate cases 7
- Diuresis to promote irrigant elimination 7
Complete resolution of symptoms typically occurs with appropriate sodium correction. 3
Common Pitfalls
- Attributing headache to anesthesia alone without checking sodium levels - TURP syndrome can develop under both spinal and general anesthesia 8
- Rapid sodium correction - increases risk of central pontine myelinolysis 7
- Continuing resection when early signs appear - immediate cessation is mandatory 2, 8
- Using glycine irrigant routinely when safer alternatives exist 6