Internal Medicine

0521779407-17 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:19

Pseudomonas Infections 1233

■CXR with bilateral, diffuse bronchopneumonia; presence of nodular

densities suggestive but not diagnostic of Pseudomonas

■Bone films, CT or MRI may be helpful in septic arthritis/osteo-

myelitis.

■MRI, bone scan and indium WBC scan helpful in diagnosing and

following course of basilar skull osteomyelitis

differential diagnosis

■Includes other pyogenic bacteria that cause similar syndromes

management

■Assess severity of illness; acute, rapidly progressive disease (meningi-

tis, sepsis, necrotizing pneumonia, corneal ulcer, burn wound infec-

tion) or infection in an immunocompromised patient requires use

of empiric antibiotics before culture results known.

■General supportive care

specific therapy

■A number of antibiotics active againstPseudomonas includ-

ing aminoglycosides (tobramycin, amikacin), cephalosporins (cef-

tazidime, cefipime), anti-pseudomonal penicillins (piperacillin,

mezlocillin, ticarcillin), fluoroquinolones (ciprofloxcin the most

active), monobactams (aztreonam), and carbapenems (imipenem,

meropenem)

■No definitive evidence that use of two drugs improves outcome

compared to single-drug therapy; however, in severe infections or

infections in immunocompromised patients, two drugs are used

initially (until clinical improvement), with completion of ther-

apy with a single agent; common combinations include an anti-

pseudomonal penicillin or cephalosporin plus an aminoglycoside or

a fluoroquinolone; two beta-lactam drugs should be avoided (pos-

sible antagonism)

■Urinary Tract Infections – uncomplicated cystitis treated 3 days,

pyelonephritis 2 weeks

■Pneumonia – 2–3 weeks; in cystic fibrosis higher doses of antibiotics

required because of increased clearance and volume of distribution);

nebulized tobramycin improves pulmonary function in colonized,

clinically stable patients with cystic fibrosis, but inhaled antibiotics,

though often used, are not of proven benefit in treating acute exac-

erbations

■Bacteremia – 2–3 weeks