Empiric antibiotic therapy should be initiated in VAP/HAP based on clinical criteria after sending blood and respiratory tract cultures. The best guide to the empiric regimen is data on local microbiological flora and resistance profiles. In absence of such data, the empiric choice can be made as mentioned in the table below:

CLABSI due to Gram positive cocci and suggested antibiotics

Etiology	Suggested regimens		Special Remarks
	Preferred/early onset/minimum prior antibiotic exposure	Alternative/late onset/prior antibiotic exposure
Empiric (VAP/HAP)	Cefoperazone –Sulbactam or Piperacillin-tazobactam Either alone or with Amikacin	Meropenem Or Imipenem-Cilastatin Plus either Amikacin Or Ceftazidime-Avibactam + Aztreonam OR Colistin/polymyxin B* *In settings where carbapenem resistance is >20%	Levofloxacin (750 mg IV q24h) may be used as an alternative to amikacin as a second anti-pseudomonal agent. Consider adding nebulized colistin for carbapenem resistant organisms along with IV colistin Empirical therapy for MRSA recommended if prevalence >10-20% in the setting
Culture proved VAP/HAP Most commonly (Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa)	hoose any one according to culture sensitivity from: Piperacillin-Tazobactam Cefoperazone –Sulbactam, Imipenem-Cilastatin, Meropenem, Colistin Polymyxin B		Colistin and Polymixin B should be used only when there is resistance to all the other tested antibiotics. For HAP/VAP due to CRE who remain in septic shock/ at high risk for the poor outcome, combination therapy using 2 antibiotics to which the isolate is susceptible rather than monotherapy is preferred
MRSA	Inj. Linezolid	Inj. Vancomycin or Inj. Teicoplanin	The choice between vancomycin and linezolid to be guided by patient-specific factors (renal functions, concomitant bacteraemia )

For Carbapenem resistant organisms; refer to guidelines of CRO

• In susceptible cases, Levofloxacin may be used as an oral step-down therapy.
• Faropenem should not be used as a step-down therapy in VAP/HAP susceptible to Carbapenems.
• Tigecycline is not recommended routinely in the treatment of VAP.
• If a patient with suspected VAP has septic shock and rapidly deteriorating status, empiric coverage for MRSA and carbapenem resistant GNB can be added along with antipseudomonal beta-lactam.
• Antibiotic doses should be adjusted according to GFR and ideal body weight except in those with morbid obesity where the dose is calculated using this formula = (actual body weight + ideal body weight)/2

General comments

1. De-escalation should be done once the culture reports are available.
2. Recommended duration of therapy: 7 days if there is a good clinical response or longer if clinically indicated (immunodeficiency, empyema, lung abscess, cavitations, necrotising pneumonia, etc)
3. Clinical picture and procalcitonin levels may be used to guide discontinuation of antibiotics.