Aerosolized colistin as adjunctive treatment of ventilator-associated pneumonia due to multidrug-resistant Gram-negative bacteria: a prospective study.
BACKGROUND
Ventilator-associated pneumonia (VAP) remains the leading cause of death in patients with intensive care unit (ICU) acquired infections associated with an attributable mortality around 30%. Increasing antimicrobial resistance in patients with VAP challenges intensivists to search for alternative therapeutic options. There is scarcity of data in the literature concerning the administration of aerosolized colistin in critically ill patients with VAP due to multidrug-resistant (MDR) Gram-negative pathogens.


METHODS
To assess the safety and effectiveness of aerosolized colistin as an adjunctive to the intravenous antimicrobial therapy for the treatment of VAP due to MDR Gram-negative pathogens, we prospectively examined all patients, who received inhaled colistin.


RESULTS
Sixty critically ill patients with a mean APACHE II score 16.7, received aerosolized colistin for the treatment of VAP due to MDR pathogens [Acinetobacter baumannii (37/60 cases), Pseudomonas aeruginosa (12/60 cases) and Klebsiella pneumoniae strains (11/60 cases)]. Half of the isolated pathogens were susceptible only to colistin. Mean (+/-SD) daily dosage of aerosolized colistin was 2.2 (+/-0.7) million international units (IU). All patients received 2946 inhalations of colistin and the mean duration of administration was 16.4 days. Fifty-seven patients received concomitant intravenous treatment with colistin or other antimicrobial agents. Bacteriological and clinical response of VAP was observed in 50/60 (83.3%) patients. No adverse effects related to inhaled colistin were recorded. All cause hospital mortality was 25% while mortality attributable to VAP was 16.7%.


CONCLUSIONS
Aerosolized colistin may be considered as adjunctive to intravenous treatment in patients with VAP due to MDR Gram-negative bacteria susceptible to colistin in critically ill patients. Although colistin is safe and effective, the best route of administration remains unclear. In addition, controlled comparative studies are needed to establish its effectiveness and safety.
Intensive Care Unit, Henry Dunant Hospital, Department of Medicine, Athens, Greece. amichalopoulos@hol.gr
Argyris
A
Michalopoulos
Dimitrios
D
Fotakis
Simona
S
Virtzili
Christodoulos
C
Vletsas
Sylvia
S
Raftopoulou
Zefi
Z
Mastora
Matthew E
ME
Falagas
D000280:Administration, Inhalation; D000328:Adult; D000336:Aerosols; D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D003091:Colistin / Q000008:administration & dosage*; D018432:Drug Resistance, Multiple; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy*; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D018410:Pneumonia, Bacterial / Q000188:drug therapy*; D053717:Pneumonia, Ventilator-Associated / Q000188:drug therapy* / Q000209:etiology; D011446:Prospective Studies; D016896:Treatment Outcome
D000336:Aerosols; D000900:Anti-Bacterial Agents; D003091:Colistin