PDPH — Recognition, Conservative Management, Epidural Blood Patch Protocol

CSF leaks through the dural defect faster than the choroid plexus can replace it → loss of CSF buoyancy supporting the brain → caudal traction on pain-sensitive structures (meninges, dural sinuses, bridging veins, CN V/IX/X).

Compensatory cerebral venodilation (Monro-Kellie doctrine) adds a vasodilatory component to the pain.

Larger dural defect + lower CSF pressure = worse + more persistent headache.

The dural hole created by a 17G Tuohy is roughly 100× the volume-flux of a 27G Whitacre pencil-point.

🔎Bilateral fronto-occipital with neck and shoulder pain.

Onset 24-72 hours post-procedure (occasionally immediate, occasionally up to 7 days).

NOT positional → reconsider diagnosis (migraine, tension, caffeine withdrawal, pre-eclampsia, cerebral venous sinus thrombosis, subdural hematoma).

27G Whitacre spinal: PDPH 0.5-1%.

25G Quincke: 5-10%.

17G Tuohy accidental dural puncture during epidural: 50-75% PDPH if untreated.

Orientation of bevel parallel to dural fibers (longitudinal) historically taught — modern evidence less convincing with pencil-point needles.

Hydration (PO + IV) — supports CSF production, modest benefit.

Caffeine 300-500 mg PO or 500 mg IV — cerebral vasoconstriction, transient relief in ~70% but recurrence common.

NSAIDs + acetaminophen.

Gabapentin 300-600 mg TID + pregabalin 75-150 mg BID for refractory cases.

Antiemetics for associated nausea.

Avoid opioids when possible (don't treat underlying problem + add nausea).

Sphenopalatine ganglion block — emerging minimally-invasive option: cotton-tipped applicator soaked in 4% lidocaine inserted transnasally to the posterior nasopharynx, held 5-10 min bilaterally; ~70% report some relief, repeatable, low risk.

Sterile technique, two operators (one drawing blood, one placing the epidural).

Locate epidural space at or one level below the original dural puncture (blood spreads cephalad more than caudal).

Slowly inject 15-20 mL autologous blood (drawn aseptically from antecubital), stopping if patient reports back pressure or radicular pain.

Mechanism: clot tamponade of the dural defect + reversal of cerebral venodilation from epidural mass effect.

Success ~70-90% first attempt; ~95% cumulative with repeat patch if needed.

Repeat no sooner than 24-48 hours after first.

Post-patch: lie supine 1-2 hr, avoid heavy lifting + Valsalva + air travel × 24 hr (some sources say longer).

If headache persists or recurs after a second patch, expand differential: imaging (MRI brain/spine with gadolinium — look for SDH, cerebral venous sinus thrombosis, idiopathic intracranial hypotension); neurology consult; consider non-PDPH etiology.