042 The use and misuse of antibiotic in neurosurgery

The Use and Misuse of Antibiotics in Neurosurgery

Youmans,Neurological surgeryChapter 4224/11/58

OutlineOutline

• Risks associated with antibiotic administration• General principles of ATB use• Antibiotic prophylaxis• Antibiotic treatment

Risks associated with Risks associated with antibiotic administrationantibiotic administration

• Antibiotics, like all other neurosurgical interventions• Cost and risk• Antibiotic therapy in neurosurgical patients

– prophylaxis for procedures– empirical treatment of a presumed infection– treatment of a specific Infection

• Adverse drug reaction– central nervous system (CNS) toxicities– systemic toxicities– allergic reactions– side effects– drug-drug interactions



• Sulfonamides : topiramate, glipizide, acetazolamide, furosemide

• Quinolone : ciprofloxacin, norfloxacin, ofloxacin– pseudotumor cerebi in infant or young children

• Penicillins : cloxacillin, dicloxacillin– In patients with renal insufficiency, intracranial lesions, or

alteration of the blood-brain barrier (BBB)

• Cephalosporins : cephalexin,ceftriazone,ceftazidime– Hypersensitivity : anaphylaxis, bronchospasm, urticaria, fever, or

maculopapular rash– Ceftazidime : hallucinations, confusion, encephalopathy, and

status epilepticus


• Carbapenems : meropenem, imipenem, ertapenem– Most common : nausea and vomiting– High doses of imipenem : seizure in Pt with renal insufficiency or

intracranial mass– Meropenem is less likely to induce seizures

• Aminoglycosides– Nephrotoxicity– Ototoxicity (irreversible)

• Hair cell : high frequency low frequency• Nerve fiber : high pitched and continuous tinnitus

• Polymyxins : colistin• Vancomycin


• Tetracyclines– Increase intracranial pressure pseudotumor cerebi

• Chloramphenicol– bone marrow suppression, aplastic anemia, and gray baby

syndrome

• Macrolides : azithromycin, clarithromycin– neuropsychiatric symptoms or ototoxicity(reversible)

• Linezolid– Peripheral neuropathy

• Rifampin– ataxia, confusion, dizziness, numbness, muscular weakness,

inability to concentrate, and headache

General principles of ATB useGeneral principles of ATB use• Blood-brain barrier(BBB)• Blood-CSF barrier(BCSFB)• Decrease the permeability

– Increased molecular weight, ionization, plasma protein binding, and metabolism at the barrier and the presence of efflux transporters

• Increase the permeability– Increased lipophilicity, influx transporters, and inflammation

General principles of ATB useGeneral principles of ATB use• Goal : an adequate concentration of the drug to the

proper compartment• First, the dose of the drug may be increased

– Beta-lactam

• Second, the choice of antibiotic may be changed to a drug that has greater penetration into the CNS

• Third, antibiotics may be delivered directly across the brain barriers(route)– Vancomycin, Aminoglycosides intrathecal

Antibiotic prophylaxisAntibiotic prophylaxis Systemic antibiotic prophylaxisSystemic antibiotic prophylaxis

• Clean wound – Without implant : < 1%– With implant : 8-10 %

• Dirty wound : 6-9%


• Clean Neurosurgical Procedures Level I– Prevent meningitis in craniotomy and spine surgery– Clean-contaminated operations has not been

adequately studied to allow a confident conclusion to be reached


• Clean Neurosurgical Procedures Level I– Principle

- Use an antibiotic directed at the most common organisms implicated in postoperative infection- Administer the antibiotic intravenously and time it so that a bactericidal level is obtained at the time of incision.- Repeat the antibiotic dose at intervals so that bactericidal serum levels are maintained during the operation.- Do not continue the antibiotic more than a few hours after the end of the operation.

• c


• External Ventricular Drains– Insufficient evidence to support a firm conclusion about the value of

systemic antibiotic prophylaxis in reducing infections associated with external ventricular drains

• Cerebrospinal fluid shunt– The use of antibiotic-impregnated shunt catheters– Cochrane systemic review : effectiveness

• Cerebrospinal Fluid Fistula– Can’t prevent meningitis in basilar skull fracture– Cochrane Systemic review : the practice is ineffective

Antibiotic treatmentAntibiotic treatment• Soft tissue infection• Meningitis• Empyema• Brain abscess• Ventriculitis• Shunt infection• Infection with spinal instrumentation• Vertebral osteomyelitis• Osteomyelitis of skull• Diskitis

Soft tissue infectionSoft tissue infection• Organism : staphylococci, streptococci• Oral ATB : semisynthetic penicillin, a first-generation

cephalosporin, clindamycin or erythromycin• Methicillin-resistant staphylococcus aureus :

vancomycin• Continues 7-10 days

MeningitisMeningitis• First line : Vancomycin plus cefotaxime or ceftriaxone• If suspected Pseudomonas aeruginosa, ceftazidime

should be used.• β-lactamase–producing Enterobacteriaceae or

Acinetobacter : meropenem• CSF needs to be sampled at regular intervals to ensure

that it is being sterilized• When the response to systemic antibiotic treatment is

poor during the treatment of gram-negative meningitis, the use of intraventricular antibiotics in combination with intravenous antibiotics should be considered early

MeningitisMeningitis• Intraventricular agent : gentamicin, amikacin and

polymyxin E (colistin)• Duration : continues 2 weeks after culture negative• However, the duration of therapy should always be

individualized based on the patient’s clinical response to treatment.

MeningitisMeningitis

EmpyemaEmpyema• Organisms : streptococci, staphylococci, anaerobes• Empirical ATB : third-generation cephalosporin,

vancomycin, or penicillin and metronidazole• Duration : 2 weeks of intravenous with an additional 6

weeks of oral therapy

Brain abscessBrain abscess• Empirical ATB : vancomycin, a third-generation

cephalosporin, and metronidazole• Duration : 6-8 weeks for intravenous

VentriculitisVentriculitis• Organism : gram-positive and gram-negative organisms• Empirical ATB : vancomycin plus a cephalosporin with

antipseudomonal coverage such as cefepime or ceftazidime

• Alternatively : vancomycin with meropenem• Acinetobacter and Pseudomonas : polymyxin E

(colistin)

Shunt infectionShunt infection• Organisms : methicillin-resistant S. aureus and

Staphylococcus epidermidis, Pseudomonas species• Empirical ATB : vancomycin + cephalosponrin that has

antipseudomonal activity(cefepime or ceftazidime)• Intrathecal for shunt infections that are difficult to

eradicate and fail to clear with systemic therapy

Infection with spinal instrumentationInfection with spinal instrumentation

• Organisms : staphylococcal species along with gram-negative organisms

• Empirical ATB : vancomycin + third-generation cephalosporin

• In most cases, removal of hardware is not necessary and can potentially have devastating complications because of spine instability and lack of bony fusion

• Duration : 10 – 14 days IV then oral ATB for 3-6 Months

Vertebral osteomyelitisVertebral osteomyelitis• Methicillin-resistant S. aureus : Rifampin with

vancomycin• Duration : 6 weeks of intravenous antibiotics be

administered followed by 6 weeks of oral antibiotics• Tuberculous vertebral osteomyelitis : isoniazid and

rifampin for a 6-9 month period

Osteomyelitis of the skullOsteomyelitis of the skull• Empirical ATB : vancimycin + 3rd cephalosporin +

metronidazole• Duration : at least 4 weeks and oral ATB followed

DiskitisDiskitis• Organisms : methicillin-resistant S. aureus• Empirical ATB : vancomycin + 3rd cephalosporin

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042 The use and misuse of antibiotic in neurosurgery