Nosocomial Pneumonia: Treatment & Medication

From: e-medicine

Nosocomial Pneumonia: Treatment & Medication
Author: Burke A Cunha, MD, Professor of Medicine, State University of New York School of Medicine at Stony Brook; Chief, Infectious Disease Division, Winthrop-University HospitalContributor Information and Disclosures
Updated: May 28, 2009

Treatment
Medical Care
Patients with nosocomial pneumonia (NP; also known as hospital-acquired pneumonia [HAP] or health care–associated pneumonia [HCAP]) usually require ventilatory support at some point and usually need supplemental oxygen therapy.
Before empiric antimicrobial therapy is initiated, an attempt should be made to rule out mimics of nosocomial pneumonia. If mimics of nosocomial pneumonia can be excluded with a reasonable degree of certainty, then empiric therapy for nosocomial pneumonia is appropriate.
The precise pathogen that causes a given case of nosocomial pneumonia is usually unknown. Therefore, empiric antimicrobial therapy is the only practical approach. Delaying therapy until the pathogen is identified is not recommended. For empiric coverage of nosocomial pneumonia, monotherapy is as effective as combination therapy for early nosocomial pneumonia.
For proven pseudomonal nosocomial pneumonia, double-drug coverage with a high degree of antipseudomonal activity and a low resistance potential should be used. Optimal combinations include meropenem or doripenem plus either levofloxacin or aztreonam. Alternately, antipseudomonal penicillin (eg, piperacillin) in combination with levofloxacin, meropenem, aminoglycoside, or aztreonam may provide equal efficacy.

Principles of appropriate empiric antibiotic coverage in nosocomial pneumonias
Direct empiric coverage against common nosocomial pathogens P aeruginosa, Klebsiella species, E coli, and MRSA. Coverage against P aeruginosa also covers other nosocomial pneumonia pathogens.
Enterobacter species, S maltophilia, and Burkholderia cepacia: Enterobacter species usually do not cause nosocomial pneumonia. S maltophilia and B cepacia are common colonizers of respiratory secretions but rarely, if ever, cause nosocomial pneumonia in most hosts; however, they are potential pathogens in patients with bronchiectasis or cystic fibrosis.
Oropharyngeal anaerobes are unimportant from a therapeutic standpoint, as they are not typically isolated in nosocomial pneumonia.

Empiric monotherapy versus combination therapy
The optimal empiric monotherapy for nosocomial pneumonia consists of ceftriaxone, ertapenem, levofloxacin, or moxifloxacin. Monotherapy may be acceptable in patients with early-onset HAP. Avoid monotherapy with ciprofloxacin, ceftazidime, or imipenem, as they are likely to induce resistance potential. Late-onset HAP, ventilator-associated pneumonia (VAP), or HCAP requires combination therapy using an antipseudomonal cephalosporin, beta-lactam, or carbapenem plus an antipseudomonal fluoroquinolone or aminoglycoside plus an agent such as linezolid or vancomycin to cover MRSA.

Optimal combination regimens for proven P aeruginosa nosocomial pneumonia include (1) piperacillin/tazobactam plus amikacin or (2) meropenem plus levofloxacin, aztreonam, or amikacin. Avoid using ciprofloxacin, ceftazidime, gentamicin, or imipenem in combination regimens, as combination therapy does not eliminate the resistance potential of these antibiotics. When selecting an aminoglycoside for a combination therapy regimen, amikacin once daily is preferred to gentamicin or tobramycin to avoid resistance problems. When selecting a quinolone in a combination therapy regimen, use levofloxacin, which has very good anti– P aeruginosa activity (equal or better than ciprofloxacin at a dose of 750 mg).

Consultations
Consult an infectious disease specialist to assess the microbiology of the specimens obtained from the patient, to rule out the mimics of nosocomial pneumonia, and to administer empiric or specific empirical antimicrobial therapy.
Consult a pulmonologist to help with mechanical ventilation (often required in patients with nosocomial pneumonia).
Other consultations include the following:
Rheumatologist, if the patient appears to have lupus or SLE pneumonitis
Cardiologist, if the patient has heart failure
Oncologist for possible pulmonary infiltrates caused by a lymphangitic spread of a malignancy
Diet
Most patients with nosocomial pneumonia are intubated and are instructed to receive nothing by mouth (NPO).
Activity
Most patients with nosocomial pneumonia are intubated and are limited to bed rest.
Medication
Ordinarily, nosocomial pneumonia (NP; also known as hospital-acquired pneumonia [HAP] or health care–associated pneumonia [HCAP]) is treated for 14 days. If the patient indeed has nosocomial pneumonia and the appropriate antimicrobial therapy is administered, chest radiography shows significant improvement in the pulmonary infiltrate during the 2 weeks of antimicrobial therapy. Pulmonary infiltrates that are unchanged after a 2-week course of therapy suggest that the infiltrates may not be infectious in origin. Start a diagnostic workup to consider other infectious diseases that do not respond to antibiotics (eg, herpesvirus type 1 [HSV-1] pneumonitis) or noninfectious diseases (eg, bronchogenic carcinomas).
Antibiotics
Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.
Cefepime (Maxipime)
A fourth-generation cephalosporin with good gram-negative coverage similar to ceftazidime; however, better gram-positive coverage than ceftazidime is equivalent in its coverage of P aeruginosa. This drug may be more active than ceftazidime against Enterobacter species because of its enhanced stability against beta-lactamases.
Dosing
Interactions
Contraindications
Precautions
Adult
2 g IV q12h
Pediatric
50 mg/kg IV q8h
Dosing
Interactions
Contraindications
Precautions
Probenecid at a high dose decreases cefepime clearance; vancomycin, polymyxin B, colistin, loop diuretics, and aminoglycosides increase the risk of nephrotoxicity
Dosing
Interactions
Contraindications
Precautions
Documented hypersensitivity
Dosing
Interactions
Contraindications
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Adjust dose in patients with severe renal insufficiency
Meropenem (Merrem)
A carbapenem, not a beta-lactam antibiotic. Bactericidal broad-spectrum carbapenem antibiotic that inhibits cell wall synthesis. Effective against most gram-positive and gram-negative bacteria. Has slightly increased activity against gram-negative bacteria and a slightly decreased activity against staphylococci and streptococci when compared to imipenem.
Dosing
Interactions
Contraindications
Precautions
Adult
1 g IV q8h (normal renal function)
Pediatric
<10>10 years: Administer as in adults
Dosing
Interactions
Contraindications
Precautions
Probenecid may inhibit renal excretion and increase meropenem levels
Dosing
Interactions
Contraindications
Precautions
Documented hypersensitivity
Dosing
Interactions
Contraindications
Precautions
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Pseudomembranous colitis and thrombocytopenia may occur, requiring immediate discontinuation of medication
Piperacillin (Pipracil)
Antipseudomonal penicillin. Acts on bacterial cell walls. Greatest degree of antipseudomonal activity among the antipseudomonal penicillins. Inhibits biosynthesis of cell wall mucopeptides and stage of active multiplication; has antipseudomonal activity. Used in combination with other antibiotics.
Dosing
Interactions
Contraindications
Precautions
Adult
4 g IV q8h (normal renal function)
Pediatric
<10>10 years: Administer as in adults
Dosing
Interactions
Contraindications
Precautions
Tetracyclines may decrease effects; piperacillin at high concentrations may physically inactivate aminoglycosides; probenecid may increase levels of piperacillin; coadministration with aminoglycosides has synergistic effects
Dosing
Interactions
Contraindications
Precautions
Documented hypersensitivity
Dosing
Interactions
Contraindications
Precautions
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
May interfere with platelet function in patients requiring surgery; caution in renal impairment and in history of seizures
Aztreonam (Azactam)
A monobactam, not a beta-lactam antibiotic, inhibits cell wall synthesis during bacterial growth. Active against gram-negative bacilli.
Dosing
Interactions
Contraindications
Precautions
Adult
2 g IV q8h (normal renal function)
Pediatric
<10>10 years: Administer as in adults
Dosing
Interactions
Contraindications
Precautions
Tetracyclines may reduce effects of this medication
Dosing
Interactions
Contraindications
Precautions
Documented hypersensitivity
Dosing
Interactions
Contraindications
Precautions
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Adjust dose in renal insufficiency
Amikacin (Amikin)
Used for gram-negative bacterial coverage of infections resistant to gentamicin and tobramycin. Effective against P aeruginosa. Irreversibly binds to 30S subunit of bacterial ribosomes, blocks recognition step in protein synthesis, and causes growth inhibition. Use patient's ideal body weight for dosage calculation.
Dosing
Interactions
Contraindications
Precautions
Adult
15 mg/kg/d IV/IM divided bid; not to exceed 1.5 g/d regardless of higher body weight
Pediatric
Administer as in adults
Dosing
Interactions
Contraindications
Precautions
Coadministration with other aminoglycosides, penicillins, cephalosporins, and amphotericin B increases nephrotoxicity; enhances effects of neuromuscular blocking agents; causes respiratory depression; irreversible hearing loss may occur with coadministration of loop diuretics
Dosing
Interactions
Contraindications
Precautions
Documented hypersensitivity
Dosing
Interactions
Contraindications
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Not intended for long-term therapy; caution in patients with renal failure (not on dialysis), hypocalcemia, myasthenia gravis, and conditions that depress neuromuscular transmission
Levofloxacin (Levaquin)
Second-generation quinolone. Acts by interfering with DNA gyrase in bacterial cells. This is a bactericidal and is highly active against gram-negative and gram-positive organisms including P aeruginosa. For pseudomonal infections and infections caused by multidrug-resistant gram-negative organisms.
Dosing
Interactions
Contraindications
Precautions
Adult
750 mg PO/IV q24h (normal renal function)
Pediatric
<18>18 years: Administer as in adults
Dosing
Interactions
Contraindications
Precautions
Antacids, iron salts, and zinc salts may reduce serum levels; administer antacids 2-4 h before or after taking fluoroquinolones; cimetidine may interfere with metabolism of fluoroquinolones; levofloxacin reduces therapeutic effects of phenytoin; probenecid may increase levofloxacin serum concentrations; may increase toxicity of theophylline, caffeine, cyclosporine, and digoxin (monitor digoxin levels); may increase effects of anticoagulants (monitor PT)
Dosing
Interactions
Contraindications
Precautions
Documented hypersensitivity
Dosing
Interactions
Contraindications
Precautions
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
In prolonged therapy, perform periodic evaluations of organ system functions (eg, renal, hepatic, hematopoietic); adjust dose in renal function impairment; superinfections may occur with prolonged or repeated antibiotic therapy
Piperacillin and tazobactam sodium (Zosyn)
Antipseudomonal penicillin plus beta-lactamase inhibitor. Inhibits biosynthesis of cell wall mucopeptide and is effective during stage of active multiplication.
Dosing
Interactions
Contraindications
Precautions
Adult
4.5 g (piperacillin 4 g and tazobactam 0.5 g) IV q6h
Pediatric
<12>12 years: Administer as in adults
Dosing
Interactions
Contraindications
Precautions
Tetracyclines may decrease effects of piperacillin; high concentrations of piperacillin may physically inactivate aminoglycosides if administered in same IV line; effects when administered concurrently with aminoglycosides are synergistic; probenecid may increase penicillin levels; high-dose parenteral penicillins may result in increased risk of bleeding
Dosing
Interactions
Contraindications
Precautions
Documented hypersensitivity; severe pneumonia, bacteremia, pericarditis, emphysema, meningitis and purulent or septic arthritis should not be treated with an oral penicillin during the acute stage
Dosing
Interactions
Contraindications
Precautions
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Perform CBC count prior to initiation of therapy and at least weekly during therapy; monitor for liver function abnormalities by measuring AST and ALT levels during therapy; exercise caution in patients with hepatic insufficiencies; perform urinalysis and BUN and creatinine determinations during therapy and adjust dose if values become elevated; monitor blood levels to avoid possible neurotoxic reactions
Doripenem (Doribax)
Carbapenem antibiotic. Elicits activity against a wide range of gram-positive and gram-negative bacteria. Indicated as a single agent for complicated intra-abdominal infections caused by susceptible strains of E coli, Klebsiella pneumoniae, P aeruginosa, Bacteroides caccae, B fragilis, Bacteroides thetaiotaomicron, Bacteroides uniformis, Bacteroides vulgatus, Streptococcus intermedius, Streptococcus constellatus, and Peptostreptococcus micros.
Dosing
Interactions
Contraindications
Precautions
Adult
500 mg IV q8h infused over 1 hCrCl 30-49: 250 mg IV q8hCrCl 11-29: 250 mg IV q12h
Pediatric
<18>18 years: Administer as in adults

Blogger comment:
For less severe hospital acuired pneumonia: Levaquin 750 mg IV Q 24 h, Invanz 1 gram IV q 24 hours or rocephin 1 gram IV q 24 hours. For late hospital acquired pneumoina or ventilator associated psudomonus and MRSA commonly need to be covered. combination therapy using an antipseudomonal cephalosporin, beta-lactam, or carbapenem plus an antipseudomonal fluoroquinolone or aminoglycoside plus an agent such as linezolid or vancomycin to cover MRSA.
Zosyn 3.375 mg IV q6h + levaquin 750 mg IV q 24 h + vancomycin 1 gram IV q 12 h in patiens with normal kidney function otherwise adjust for GFR.