Septic shock in association with pneumonia portends high morbidity and mortality. Appropriate and rapidity of institution of effective antimicrobial therapy and development of multiple organ failure are important determinants of outcome in these patients. This study examined the epidemiology and predictors of mortality in these patients.
A retrospective study of geographically and temporally comprehensive cohort of patients admitted to all the intensive care units in one city with a diagnosis of pneumonia and septic shock. CDC definition and SCCM criteria were used to identify patients with pneumonia and septic shock. Data on patient demographics, bacteriology, outcome measures, antimicrobial and supportive therapies were extracted and analyzed.
In 502 patients (CAP 47.7%, HAP 37.1%) who met study criteria, average age was 62 ± 16.9 years, 58.6% were male, average APACHE II score was 26.8 ± 8.5. Ventilatory support was required in 88.8% of patients. Renal failure serum creatinine rise to 1.5X baseline) occurred in 58.5%, CNS manifestations (altered level of consciousness) in 45.8% and hepatic dysfunction (bilirubin rise by 2.5X baseline) in 18.3%. Survival to hospital discharge was 50.6% and 30 day survival at 43.8%. Survival was no different in CAP vs. HAP patients (47.7% vs. 37.1%) In 64.9% a pathogen was isolated, 20.9% were bacteremic. The pathogens were S. aureus 16.1%, S. pneumoniae 11.6%, E.coli 6%, P. aeruginosa 5.4%, H. influenzae 3.8% and Enterobacter species 3.2%. Time to antibiotic administration (mean 11.1 hrs, median 6 hrs) strongly correlated with mortality (p<0.00001). Inappropriate antibiotic therapy (19.3%) compared to appropriate therapy led to dismal survival (11.3% vs. 51.6%).
Pneumonia associated with septic shock carries a high mortality. Despite empiric pneumonia guidelines, a significant proportion received delayed and inappropriate antibiotic therapy. Failure to receive antibiotics in timely fashion was a strong predictor of mortality in these patients.
Substantial delays in appropriate antibiotic administration following onset of hypotension exists. Early, appropriate antimicrobial agents in addition to supportive therapy in patients with pneumonia and septic shock will lead to improved outcome.
S. Sharma, None.