Antibiotic prophylaxis of early onset pneumonia in critically ill comatose patients. A randomized study.

OBJECTIVE: To evaluate if a 3-day ampicillin-sulbactam prophylaxis can reduce the occurrence of early-onset pneumonia (EOP) in comatose mechanically-ventilated patients. DESIGN: This was a single-centre, prospective, randomised, open study. SETTING: A 10-bed general-neurological ICU in a 2,000-bed university hospital. PATIENTS AND PARTICIPANTS: Comatose mechanically-ventilated patients with traumatic, surgical or medical brain injury. INTERVENTIONS: Patients were randomized to either ampicillin-sulbactam prophylaxis (3 g every 6 h for 3 days) plus standard treatment or standard treatment alone. MEASUREMENTS AND RESULTS: Main outcome was the occurrence of EOP. Secondary outcome measures were occurrence of late-onset pneumonia, percentage of non-pulmonary infections and of emerging multiresistant bacteria, duration of mechanical ventilation and of ICU stay and ICU mortality. Interim analysis at 1 year demonstrated a statistically significant reduction of EOP in the ampicillin-sulbactam group, and the study was interrupted. Overall, 39.5% of the patients developed EOP, 57.9% in the standard treatment group and 21.0% in the ampicillin-sulbactam group (chi-square 5.3971; P =0.022). Relative risk reduction of EOP in patients receiving ampicillin-sulbactam prophylaxis was 64%; the number of patients to be treated to avoid one episode of EOP was three. No differences in other outcome parameters were found; however, the small sample size precluded a definite analysis. CONCLUSIONS: Antibiotic prophylaxis with ampicillin-sulbactam significantly reduced the occurrence of EOP in critically ill comatose mechanically ventilated patients. This result should encourage a large multicenter trial to demonstrate whether ampicillin-sulbactam prophylaxis reduces patient mortality, and whether antibiotic resistance is increased in patients receiving prophylaxis.

Surveillance of infections acquired in intensive care: usefulness in clinical practice.

Nosocomial infection surveillance is common in the USA and in some European countries but in Italy few hospitals use it. In order to evaluate its usefulness in clinical practice we performed a one year prospective epidemiological study that included 178 patients, admitted to an intensive care unit (ICU) for more than 48 h. Median ICU stay was 16 days. Trauma and neurological diseases accounted for 65% of admissions. The selected population had high severity scores and required a large number of invasive procedures for diagnosis and therapy. The most common infections were: pneumonia 46/1000 ventilator-days; urinary tract infections 17/1000 catheter-days; central venous catheter infections 14.5/1000 catheter-days with 1.7/1000 CVC-related sepsis; bacteraemic sepsis 12/1000 ICU-days. The most frequent pathogens were Staphylococcus aureus,Pseudomonas aeruginosa, other Gram-negative aerobes and Candida spp. Antimicrobial resistance was substantial, with 68% methicillin-resistance in S. aureus and 76% of P. aeruginosa displaying antibiotic resistance. Severe sepsis or septic shock occurred in 30 patients (8/1000 ICU-days), and three patients died from septic shock of unknown origin (10% case fatality rate). There were no case fatalities for pneumonia and bacteraemic sepsis. Overall, ICU-acquired infections were not associated with an increased risk of death.