Synopsis
Recognise infection after cranial surgery, define whether it is superficial, deep, bone- or implant-associated, or intracranial, and coordinate imaging, operative sampling and source control without treating every wound change as one syndrome.
- First define depth: superficial incisional infection involves skin/subcutaneous tissue; deep infection involves fascia, muscle, bone flap or implant; organ-space infection includes epidural/subdural empyema, brain abscess or meningitis/ventriculitis.
- Wound appearance alone cannot define intracranial extension. New headache, seizure, focal deficit, meningism, reduced consciousness or CSF leakage prompts immediate neurosurgical review and contrast CT or MRI with DWI as appropriate.
- Obtain blood cultures in systemic illness and deep operative tissue/fluid cultures before antibiotics when this causes no unsafe delay; a superficial swab can misrepresent colonisation and must not be the sole deep-infection sample.
Key red flags
Wound dehiscence, purulent drainage, exposed bone or implant, fluctuant swelling or a persistent CSF-like leak after craniotomy.
Fever or rigors with severe headache, meningism, photophobia, seizure, focal deficit, confusion or falling GCS suggests intracranial or systemic extension.
Rapidly expanding scalp swelling, crepitus, severe pain, skin necrosis or sepsis physiology requires immediate operative and critical-care assessment.
New neurological decline after an initially improving postoperative course demands urgent imaging for empyema, abscess, ventriculitis, haemorrhage, infarction and hydrocephalus.
A cranioplasty, bone flap, fixation plate, shunt, drain or other cranial implant changes biofilm risk and the source-control decision.
Recent antibiotics may suppress fever and superficial culture yield; an apparently clean surface does not exclude deep or organ-space infection.
Dehiscence, persistent sinus, purulence, exposed hardware, bone-flap pain or instability and recurrent drainage suggest deep incisional, bone or biofilm-associated infection.
Severe headache, meningism, seizure, focal deficit, reduced consciousness or imaging evidence of epidural/subdural collection, brain abscess or ventriculitis marks intracranial infection.
Clear or blood-tinged fluid from the wound, nose or ear after cranial surgery can create an infection route; confirm clinically and involve the operating team rather than repeatedly manipulating the wound.
Reasoning priorities
Define surface findings, dehiscence, CSF leakage, implant exposure and evidence of intracranial extension.
Document wound edges, tenderness, warmth, drainage character, fluctuance and neurological baseline. Do not probe or manipulate a possible deep tract outside the surgical plan.
Worked reasoning
Two weeks after craniotomy, a patient has wound separation and purulent drainage, fever and a new focal seizure.
- Treat this as deep or organ-space infection: stabilise, treat the seizure, document neurology and call the operating neurosurgeon plus infection/microbiology teams immediately.
- Take blood cultures if this causes no delay and obtain urgent CT, followed by contrast MRI with DWI when appropriate, to define collections and intracranial complications.
- Start the current local post-neurosurgical empirical regimen after cultures, or immediately if unstable, and prepare operative exploration, debridement and deep sampling.
- At surgery, define skin, galea, bone flap, fixation/implant and organ-space involvement; decide removal, retention or staged reconstruction from viability, purulence and the full source-control context.
- Narrow therapy to deep culture results and monitor wound, neurology and imaging; manage CSF leak, meningitis/ventriculitis or abscess through their distinct pathways.