Q: What is the recommended antibiotics for community acquired pneumonia (CAP) for patients admitted in ICU? 

Answer: 

According to  IDSA/ATS guidelines, for patients with severe CAP requiring ICU admission, 

A beta-lactam (ceftriaxone, cefotaxime, ampicillin-sulbactam) plus either intravenous azithromycin or an antipneumococcal fluoroquinolone.

If Pseudomonas is a concern, an antipseudomonal agent (piperacillin-tazobactam, imipenem, meropenem, or cefepime) PLUS an antipseudomonal fluoroquinolone (ciprofloxacin or high-dose levofloxacin).

If MRSA is a concern, either vancomycin or linezolid should be added.

Reference: 

Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. - Clin Infect Dis. 2007;44 Suppl 2:S27.