Specific infections and causative organisms

OVERVIEW

  • key infections, organisms and suggested treatments
  • antibiotic selection varies by geographic location and institution – consult local guidelines and sensitivity patterns

ABDOMINAL SEPSIS

  • includes: acute peritonitis, appendicitis, cholangitis, cholecystitis, diverticulitis, PID
  • Empiric Treatment – Cefuroxime + Metronidazole OR Tazocin

ANIMAL CONTACT

  • Chlamydophila psittaci (birds -> pneumonia)
    – Erythromycin (macrolides) or Moxifloxacin (quinolones)
  • Coxiella burnetii (Q fever) – pregnant animals and hides -> pneumonia + endocarditis)
    – Doxycycline or Chloramphenicol
  • Burcella suis (feral pigs)
    – Doxycycline + Rifampicin/Gentamicin
  • Burcella abortis (stock animals)
    – Doxycycline + Rifampicin/Gentamicin
  • Leptospirosis (rats)
    – Doxycycline or Benzylpenicillin
  • Toxoplasma gondii (cats)
    — Pyrimethamine
  • Hydatid disease = Echinococcus granulosus (dog faeces)
    – surgical resection + albendazole
  • Cysticercosis (infected meat esp pork)
  • Bacillus antracis (wool)
    – penicillin, doxycycline or ciprofloxacin
  • Bartonella henselae – (cat scratch disease)
    – doxycycline, macrolides, cotrimoxazole, ciprofloxacin, gentamycin
  • Cryptosporidiosis (domestic and wild animals)
    – no specific treatment

BITES/PUNCH INJURIES

Empiric Antibiotics

  • Prophylaxis – Amoxycillin + Clavulanate OR Doxycycline + Metronidazole
  • Established Infection – Amoxycillin Clavulanate OR Cefazolin + Metronidazole

Organisms:

  • Staph. aureus
  • Streptococcus
  • Anaerobes (including Clostridium tetani)
  • Eikenella corrodens (human)
  • Pasteurella (cats and dogs)
  • Capnocytophagia canimorsus (cats and dogs)
  • Bartonella henselae (cat scratch)
  • Lyssa virus (bats)

Tetanus Immunisation!

CELLULITIS

Empiric Antibiotics

  • Flucloxacillin OR Cephazolin

DIARRHOEA

Primary

Empiric antibiotics

  • only indicated in the really sick -> ciprofloxacin or norfloxacin

Organisms

  • Shigella species
  • Salmonella species
  • Campylobacter species
  • Yersina enterocolitica
  • Enterohaemorrhagic Escherchia coli (EHEC)
  • Entamobeba histolytica

Antibiotic-induced

Empiric antibiotics

  • Metronidazole

ENCEPHALITIS

Empiric Treatment – Acyclovir (HSV) or Ganciclovir (CMV)

  • HSV
  • CMV
  • EBV
  • HSV – type 6
  • Arboviruses
  • Coxsackie viruses
  • Enteroviruses
  • Echoviruses
  • Adenoviruses
  • Influenzae viruses
  • Hepatitis A virus
  • Murray Valley encephalitis
  • Hendra viruses (equine morbillivirus)
  • Japanese encephalitis
  • HIV
  • Toxoplasma gondii
  • Plasmodium falciparum
  • Rickettsieae
  • Borrelia burgdorferi
  • CJD
  • Rubella
  • Measels

ENDOCARDITIS

Empiric Antibiotics

Native valves

  • Flucloxacillin OR Cephazolin +/- Gentamicin

Prostetic valves or Hospital Acquired

  • Flucloxaillin OR Vancomycin + Rifampicin + Gentamicin

Organisms

  • Staphylococci (aureus, lugdenensis)
  • Streptococci (viridans, sanguis)
  • Enterococci
  • Oral gram negative bacilli – (HACEK group: Haemophilus (parainfluenaze, aphrophilus), Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae)
  • Coxiella burnetii
  • Legionella
  • Bartonella
  • Pseudomonas aeruginosa
  • Neisseria gonorrhoea
  • Corynebacterium diptheriae
  • Fungi – Candida and Aspergillus

MENINGITIS

Dexamethasone

  • 0.15mg/kg IV with first antibiotic

Empiric Antibiotics

  • Ceftriaxone + Vancomycin

Organisms

  • Streptococcus pneumoniae
  • Niesseria meningitides
  • Haemophilus influenzae
  • Listeria monocytogenes (age extremes)
  • Steptococcus agalactaie (neonates)
  • Escherichia coli (neonates)
  • Staph + Gram-negative bacilli (skull trauma or neurosurgery)
  • Mycobacterium tuberculosis
  • Cryptococcus neformans (immunosuppressed)
  • Leptospira interrogans
  • Burcella
  • Borrelia bugdoferi
  • Treponema pallidum
  • Viruses – Enteroviruses, Abroviruses, Coxsackie viruses

MYONECROSIS (gas gangrene)

Empiric Treatment

  • Surgical Debridement -> Benzylpenicillin or Metronidazole

Organisms

  • Clostridium perfringens or Clostridium septicum

NECK INFECTIONS

Empiric antibiotics

  • Pencillin + Clindamycin + Gentamicin OR Third generation Cephalosporin + Metronidazole

Types

  • Ludwig angina – sublingual/submaxillary space infection
  • Retropharyngeal and parapharyngeal space infections
  • Lemierre syndrome – retrotonsillar infection with the anaerobe Fusobacterium necrophorium which enters the jugular vein and disseminates

Organisms

  • – mixed oral flora (gram positive, negative and anaerobes)
    – S. pyogenes
    – S. viridans
    – S. pneumoniae
    – S. aureus
    – Fusobacterium nucleastum
    – Bacteroides oralis
    – Spirochaeta
    – Peptostreptococcs
    – Neisseria spp
    – Pseudomonas
    – E.coli
    – H. influenzae

NECROTISING FASCIITIS

Empiric Treatment

  • Surgical Debridement
  • Meropenem + Clindamycin
  • New antibiotic guidelines: flucloxacillin + clindamycin

Organisms

  • – Gram positive infection – Group A Streptococci, Staph aureus
    – Mixed infection – Gram negative enteric bacilli, Vibrio, Anaerobes

OSTEOMYELITIS/SEPTIC ARTHRITIS (single, native joint)

Empiric Treatment

  • Flucloxacillin OR Cephalzolin

PELVIC INFLAMMATORY DISEASE

Empiric Antibiotics

  • Ceftriaxone + Azithromycin +/- Metronidazole

Organisms

  • usually polymicrobial
  • can be sexually acquired or non-sexually acquired
  • Chlamyophilia trachomatis
  • Neisseria gonorrhoea
  • Mycoplasma hominis
  • Ureaplasma urealyticum
  • Actinomyces (if IUD in situ)

PNEUMONIA

COMMUNITY ACQUIRED PNEUMONIA

Empiric Antibiotics – Cefuroxime + Erythromycin (NZ)

  • Streptococcus pneumoniae
  • Haemophilus influenzae (underlying COPD)
  • Mycoplasma pneumoniae
  • Chlamydia pneumoniae
  • Legionella

HOSPITAL ACQUIRED PNEUMONIA

Empiric Antibiotics

  • Cefuroxime +/- Piperacillin-Tazobactam (if not responding)

Organisms

  • Aerobic gram negative bacilli (ESCAPM)
  • MRSA
  • Enterobacter (multi-drug resistant)
  • Pseudomonas aeruginosa (multi-drug resistant)
  • Acinetobacter
  • Stentrophomonas maltophilia
  • Fungi – Aspergillus
  • Viral – influenza, RSV

POST-TRAUMATIC WOUND INFECTIONS

Mild to Moderate (skin injury only, no soiling or presenting within 4 hours)

  • Flucloxacillin

Severe (wound soiling, tissue damage, devitalised tissue, perforated viscus)

  • surgery, Amoxicillin + Clavulanate +/- Gentamicin

PROSTHETIC JOINT INFECTIONS

Empiric Treatment

  • consult ID early (Vancomycin)

SEPSIS

COMMUNITIY ACQUIRED SEPSIS

  • no obvious source
  • immunocompetent adult

Empiric antibiotics

  • Ceftriaxone

HOSPITAL ACQUIRED SEPSIS

  • no obvious source
  • immunocompetent adult
  • Staph aureus = commonest pathogen

Empiric Treatment:

  • Piperacillin + Tazobactam 4.5g Q 8hrly OR Flucloxacillin + Gentamicin
  • Vancomycin (if suspected MRSA)
  • Meropenem (if suspected ESBL)

CHILDREN

Meningitis NOT excluded

  • Empiric Treatment
    < 6 months – amoxicillin + cefotaxime + vancomycin Empiric Treatment
    > 6 months – flucloxacillin + cefotaxime OR ceftriaxone + vancomycin

Meningitis excluded

  • Empiric Treatment
    < 4 months – amoxicillin + gentamicin Empiric Treatment
    > 4 months – flucloxacillin + cefotaxime OR ceftriaxone

THE IMMUNOSUPPRESSED

IMPAIRED IMMUNOGLOBULIN PRODUCTION (B-cell mediated)

  • including post-splenectomy
  • nephrotic syndrome
  • myeloma
  • CLL
  • immunosuppressive therapy
  • AIDS
  • at risk of encapsulated bacterial infection

Empiric Treatment –

  • Streptococcus pneumoniae and pyogenes
  • Enterococcus species
  • Neisseria meningitidis and gonorrhoea
  • Haemophilus influenzae
  • Salmonella species
  • Escherichia coli
  • Pseudomonas aeruginosa
  • Capnocytopaga canimorsus
  • Bacteroides species
  • Plasmodium species + other parasites

IMPAIRED CELL-MEDIATED IMMUNITY (T-cell mediated)

  • AIDS
  • immunosuppressive therapy

Empiric Treatment –

  • Pneumocystis jiroveci
  • Cryptococcus neoformans
  • Toxoplasma gondii
  • CMV
  • HSV
  • VZV
  • Fungi – Candida albicans
  • Mycobacterium tuberculosis and avium
  • Legionella species
  • Nocardia species
  • Streptococcus pneumoniae
  • Strongyloides stercoralis

IMPAIRED NEUTROPHIL NUMBER AND/OR FUNCTION

  • neutropenia = < 0.5 or expected decline to less than 0.5
  • post-chemotherapy
  • post-transplantation
  • chronic granulomatous disease

Empiric Antibiotics

  • Piperacillin-Tazobactam 4.5g Q8hrly (add Vancomycin for MRSA, add Meropenem for ESBL)

Organisms

  • Gram negative bacilli
  • Staphylococcus aureus
  • Streptococcus viridans
  • Fungi – Candida, Aspergillus, Mucormycosis (add voriconazole or amphortericin B)

TOXIC SHOCK MEDIATED EXFOLIATING SYNDROMES

Empiric Treatment

  • Antibiotics (see below) – Clindamycin (? helps stop toxin production)
  • Immunoglobulin with Streptococcus (0.4-2g/kg for 2 doses)

Staphylococcal scaled skin syndrome (Staph aureus)

  • Flucloxacillin OR Cephazolin

Streptococcal toxic shock syndrome (Group A Streptococcus)

  • Benzylpenicillin OR Cephazolin

URINARY TRACT INFECTIONS

  • uncomplicated = adult, female, no urological defect
  • complicated = all others
  • anyone 15-29 years with urethral symptoms -> send first past urine for Chlamydia

UNCOMPLICATED

Empiric antibiotics

  • Trimethoprim OR Nitrofurantoin

COMPLICATED

Empiric antibiotics

  • Cefaclor OR Nitrofurantoin (pregnancy)

COMMUNITY PYELONEPHRITIS

Empiric antibiotics

  • Gentamicin OR Cefuroxime

ACUTE PROSTATITIS

Empiric antibiotics – Cefuroxime then Ciprofloxacin

ESBL (E coli or Klebsiella)

Cystitis

  • empiric antibiotics – Nitrofurantoin or Amoxycillin-Clavulanate

Pyelonephritis

  • empiric antibiotics – Ertapenem 1g Q12hrly

WATERBORNE AGENTS

  • Aeromonas species (fresh water)
  • Shewanella putrifaciens (salt water) –
  • Vibrio species (warm salt water) – third generation cephalosporin or tetracycline (doxycycline)
  • Pseudomonas aeruginosa (spa baths) – piperacillin-tazobactam, tircarcillin-clavulanate, ceftazidime, cefepime, imipenem, meropenem
  • Legionella species (water tanks) – macrolides (erythromycin)

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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