This document discusses postoperative infections of the head and brain. It covers the epidemiology, risk factors, prevention strategies, and treatment principles for various types of infections including superficial infections, bone flap osteomyelitis, subdural empyema, brain abscess, and bacterial meningitis. Key points include that S. aureus is the most common pathogen, prevention strategies focus on proper antibiotic usage and surgical site control, and treatment requires source control through drainage/debridement combined with targeted antibiotic therapy administered for several weeks.

1. Postoperative Infections of
the Head and Brain
Youmans Neurology surgery
Chapter 40

2. Outline
• Epidemiology and etiology
• Risk factor for infection and preventive
strategies
• Principles of treatment
• Superficial infections and bone flap osteomyelitis
• Subdural empyema
• Brain abscess
• Bacterial meningitis

3. Epidemiology and etiology
• Anatomic site
– Superficial : skin and subcutaneous
– Deep : subgaleal space and bone flap
• subdural emyema, brain abscess and
meningitis(most common)
• McClelland and Hall
– Elective cranial craniotomy,over 15 yrs,low rate 0.8%
– S.aureus : most common

4. Epidemiology and etiology
• NNIS : s.aureus, coagulase-negative,
staphylococci
• Other bacteria : enterococci, Streptococcus spp.,
Pseudomonas aeruginosa, Acinetobacter spp.,
Citrobacter spp., Enterobacter spp., Klebsiella
pneumoniae, Escherichia coli, miscellaneous
other gram-negative bacilli, and yeast

5. Risk factor for infection and
preventive strategies
• Contamination of the wound with bacteria from
the patient’s skin
• Host defence mechanism : low level of antibody,
underlying pathology, corticosteroids, chemo
receptor, radiation, trauma
• Prevention of craniotomy infection :
– minimization corticosterois use,
– nutritional support
– glucose support

6. Risk factor for infection and
preventive strategies
• Korinek, predictor of infection
– surgery lasting longer than 4 hours,
– emergency surgery
– clean-contaminated and contaminated surgery
– neurosurgical intervention in the preceding month
• Synthetic dural substitutes, potential risk factor
for infection

7. Risk factor for infection and
preventive strategies
• Preoperative ATB reducing the incidence of SSI
after craniotomy
• Adhesive tape barrier, Bathing, Showing not
approved to reduce infection

8. Risk factor for infection and
preventive strategies
• The Surgical Infection Prevention (SIP)
– selection of an appropriate antibiotic,
– administration within 1 hour before incision (2
hours is allowed for the administration of
vancomycin and fluoroquinolones)
– discontinuation of the antibiotic within 24 hours
after surgery is completed

9. Risk factor for infection and
preventive strategies
• Surgical site control and environment control
– Remove hair(clipper,close to time surgery)
– Antiseptic skin prep(chlorhexidine, iodophor)
• Operating room
– Number of health care
– Traffic in the room
– Adequate ventilation
– Used of high-efficiency particulate air (HEPA)
filters

10. Principles of treatment
• keystone of successful treatment
– Effective source control (i.e., drainage of
abscesses and infected fluid collections and
débridement of necrotic )
– Antibiotic Therapy
• ATB
– Passive diffusion down concentration gradient
– Molecular weight
– Lipophilicity
– Protein binding

11. Principles of treatment
• Empirical treatment of postoperative infections
– vancomycin + a second drug such as a third- or
fourth-generation cephalosporin having
antipseudomonal activity (e.g., ceftazidime,
cefepime)
– carbapenem (e.g., meropenem)
• Vancomycin : weaker activity against
staphylococcal infections relative to β-lactams
and decreased penetration into the CNS

12. Principles of treatment
• Cefazolin : poor CNS penetration
• Third-generation cephalosporins (specifically
cefotaxime, ceftriaxone, and ceftazidime) : low
toxicity, good CNS penetration, and excellent
in vitro activity
• Carbapenems such as imipenem (with cilastatin)
and meropenem : broad antimicrobial spectrum,
brain abscess (imipinem increase seizure)

13. Principles of treatment
• Fluoroquinolones : high rate of bacterial
resistance, increased seizure potential
• Linezolid
– bacteriostatic : MRSA, vancomycin-resistant
enterococci
– bactericidal : streptococci
– IV or Oral
– SE : reversible myelosuppression and
irreversible peripheral neuropathy

14. Principles of treatment
• Rifampin
– Infection associated with foreign body implantation,
bone flap osteomyelitis
– effectively penetrate biofilms and kill organisms in the
sessile phase of growth
– Combination with a second active agent
• Daptomycin
– vitro microbicidal activity against MRSA

15. Principles of treatment
• Polymyxins
– gram-negative bacilli
– nephrotoxicity.
• Aminoglycoside
– aerobic gram-negative bacilli (P.aeruginosa)
– Toxic, narrow therapeutic window,poor CNS
penetrate

16. Superficial infections
and bone flap osteomyelitis
• Clinical manifestation
– Local erythema, swelling, tenderness, wound
breakdown, suppurative drainage
– Systemic sign : malaise, fever, chill
– Neurological symptom : meningismus, altered
mental status, or new focal deficits
– Pathogen : gram-positive cocci, including S.
aureus, coagulase-negative staphylococci, P.
acnes

17. Superficial infections
and bone flap osteomyelitis
• Diagnostic imaging and laboratory data
– CT or MRI : fluid collections in the subgaleal or
epidural spaces
– bone flap destruction suggestive of osteomyelitis
– ESR, CRP : detecting infection, monitor

18. Superficial infections
and bone flap osteomyelitis
• Treatment
– Superficial infection
• Oral : first-generation cephalosporins (e.g.,
cefazolin) or β-lactamase–resistant penicillins
(e.g., dicloxacillin)
• IV : rapidly spreading infection, prominent
systemic symptoms, or significant comorbidity

19. Superficial infections
and bone flap osteomyelitis
• Treatment
– Bone flap osteomyelitis
• ATB
• débridement with replacement of the bone flap
• surgical débridement with removal of the bone
flap

20. Superficial infections
and bone flap osteomyelitis
• Hyperbric oxygen(HBO) therapy
• Complicated superficial infection
• increases oxygen tension in infected tissues
• improving oxidative killing of aerobic bacteria by
phagocytic cells and providing a direct bactericidal
effect on anaerobic organisms such as P. acnes
• Useful in radiation injury : promote neoangiogenesis
and reverse the vascular compromise
• Limitation : cost, multiple session, increase tumour
growth

21. Subdural empyema
• Clinical manifestation
– fever and headache, followed by the rapid
development of focal neurological deficits, altered
mental status, and seizures
– most common findings were evidence of
superficial wound infection and the presence of
diffuse encephalopathy
– subdural empyema occurred more than 1 month
after the craniotomy

22. Subdural empyema
• Diagnostic imaging and laboratory data
– CT NC : crescent-shaped fluid collection, more
dense than CSF, located beneath the craniotomy
flap or adjacent to the falx
– MRI :
• T1, FLARE : increase intensity
• Gd : peripheral enhancement
– Laboratory finding
• Nonspecific : ESR normal, CSF normal
• LP contrain contraindicated  herniation

23. Subdural empyema
• Treatment
– Surgical drainage
– Craniotomy advocate (maximal drainage,
inspection of adjacent area, removal bone flap)
– Empirical ATB : skin flora, gram-negative bacilli
– Vancomycin + 3rd
cephalosporin (ceftazidime) :
P.aeruginosa
– Duration 4-6 wks

24. Brain abscess
• Clinical manifestation
– Direct seeding, extension of superficial
– classic triad of headache, fever, and focal
neurological deficit is rarely present
– Symptom : irritative mass lesion and include
altered level of consciousness, nausea, vomiting,
and seizures

25. Brain abscess
• Clinical manifestation
– Intraventricular rupture of a brain abscess
(IVROBA) :
• preexisting headache with new onset of
meningismus, coma
• severe widespread meningoencephalitis and
alterations in CSF flow causing an increase in
intracranial pressure, hydrocephalus(50%)
• Risk factor : multiloculates, near ventricular

26. Brain abscess
• Diagnostic imaging and laboratory data
– CT
• cerebritis stage : poorly defined area of low
attenuation with a mass effect and
significant edema
– MRI
• T1-weighted images as a ring of gadolinium
enhancement surrounding a necrotic cavity of
low signal intensity

27. Brain abscess
• Diagnostic imaging and laboratory data
– Corticosteroids : reduce thickness of the abscess
capsule and the extent of contrast enhancement
on both CT and MRI
– DWI MRI
• most sentivity,specifitivy for Ddx ring-
enhancing lesion (residual or recurrent tumor,
treatment effect, infarction, or resolving
hematoma)
• T2 shine-through effect : bright

28. Brain abscess
• Diagnostic imaging and laboratory data
– Peripheral leukocytosis is frequently absent
– ESR and CRP level are usually elevated,
normal values may occur in patients with
proven infection
– Blood cultures
– CSF analysis is rarely helpful and typically
reveals only a nonspecific elevation in protein
level and cell count
– -LP contraindicated

29. Brain abscess
• Treatment
– Goal : mass effect, improve clinical symptoms,
and fully resolve the infection
– Surgical : open drainage or excision of the lesion
and stereotactic aspiration(higer recurrence)
– Specimens for GS and CS
– Empirical ATB : vancomycin and a third- or
fourth-generation cephalosporin with
antipseudomonal activity (e.g., ceftazidime,
cefepime)

30. Brain abscess
• Treatment
– High dose for 6-8 Wks
– Progressive enlargement of the abscess or failure
of the abscess to become smaller despite
treatment of a susceptible organism with an
appropriate antibiotic : repeat surgical drainage
and microbiologic reassessment
– Corticosteroid : Pt c significant cerebral edema
– Antiseizure prophylaxis

31. Bacterial meningitis
• Clinical manifestation
– < 1%, mortality > 20%
– fever, headache, and neck stiffness
– sterile postoperative meningitis
• most frequently in children and after posterior
fossa surgery

32. Bacterial meningitis
• Clinical manifestation
– sterile postoperative meningitis
• presumed to be caused by irritation from
blood breakdown products or from factors
released by surgical materials such as
dural substitute
• Dx : negative CSF GS and CS
• Pt fully recovery without administration of ATB
• Corticosteriod provide symptomatic relief

33. Bacterial meningitis
• Diagnostic imaging and laboratory data
– No diagnostic test for chemical and bacterial
meningitis
– Neuroimaging studies rarely assist in the
diagnosis of postoperative meningitis
– CSF culture is gold standard for diagnostic
postoperative bacterial meningitis
– CSF Gram staining is highly insensitive for
infection

34. Bacterial meningitis
• Diagnostic imaging and laboratory data
– CSF hypoglycorrhachia and pleocytosis with
neutrophilic predominance are common findings
in both aseptic and bacterial meningitis
– CSF lactate : > 4 mmol/L, IL-1b > 90 ng/L
presence of bacterial meningitis with good
sensitivity and specificity in postsurgical patients

35. Bacterial meningitis
• Treatment
– vancomycin + third-generation cephalosporin
with antipseudomonal activity (e.g., ceftazidime)
– patient is not deteriorating clinically, CSF culture
results remain sterile, and the treating clinician
believes the original clinical syndrome to have
been consistent with aseptic chemical meningitis,
antibiotics may be discontinued after several day

36. Thank you