Guidelines for Second Line Empiric Treatment of Infections in Level 2 and 3 Critical Care
On admission to level 2 or 3 critical care, complete a full antibiotic history in relation to the active infection. Ensure adequate source control where possible (ie drainage of collections or abscesses). Consider other causes of systemic deterioration eg recent surgical intervention, acute on chronic respiratory disease. Use existing protocols for dosing of vancomycin and gentamicin. Split doses evenly in 24 hours: x 2 = every 12 hours, x 3 = every 8 hours, x 4 = every 6 hours.
(all doses IV)
|Sepsis of unknown focus||Aztreonam 2g x 4 PLUS metronidazole 500mg x 3 PLUS vancomycin (covers MRSA)||If strong suspicion of group A Strep or Staph Toxic Shock Syndrome, discuss with microbiology and consider adding clindamycin and using immunoglobulin.|
|Community acquired pneumonia||If antibiotic switch considered necessary:
Levofloxacin 500mg x 2
|If patient has following risk factors treat as HAP: recent hospital admission; recent antibiotic therapy.|
Hospital acquired pneumonia
|Aztreonam 2g x 4 PLUS vancomycin
Second line: ciprofloxacin 400mg every 8 hours PLUS vancomycin
|Severe community-acquired pneumonia where MSSA/MRSA suspected eg recent influenza or IVDU||Discuss with microbiologist ADD linezolid 600mg x 2
For treatment of microbiologically proven MSSA pneumonia: levofloxacin 500mg x 2 PLUS flucloxacillin 2g x 4
|Note: Hypertensive crises have occurred in patients taking MAOIs (linezolid is one) and metaraminol. The pressor effects of adrenaline, isoprenaline and noradrenaline may be unchanged or moderately increased.|
|Suspected necrotising staphylococcal lung infection||Suspect Panton-Valentine Leukocidin (PVL) toxin producing S. aureus strain: levofloxacin 500mg x 2 PLUS linezolid 600mg x 2||If deteriorating or severe disease consider IV immunoglobulin.|
Aspiration often leads to chemical pneumonitis - use antibiotics only treat where infection suspected
|Metronidazole 500mg x 3 PLUS amoxicillin 1g x 3
Penicillin allergy: metronidazole PLUS clarithromycin 500mg x 2
Severe infection or previous antibiotics*: aztreonam 2g x 4 PLUS amoxicillin 1g x 3 PLUS metronidazole 500mg x 3
Severe infection, penicillin allergy: levofloxacin 500mg x 2 PLUS metronidazole 500mg x 3
|Infection indicated by change in sputum quality to purulent/mucropurulent or fever and new chest X-ray changes.
* Antibiotics in the last 2 weeks increases colonisation of oropharynx and gram negative organisms.
Aztreonam 2g x 4 PLUS metronidazole 500mg x 3
|Discuss with microbiologist if illness unresponsive or severe illness.|
|Necrotising fasciitis||Meropenem 2g x 3 PLUS clindamycin 1.2g x 4||Seek urgent surgical opinion and consult microbiology (notify Public Health).|