Nosocomial pneumonia in critically ill comatose patients: need for a differential therapeutic approach

Abstract

The purpose of this prospective clinical study was to determine the incidence, bacteriology and outcome of lower respiratory tract infections developed among 208 consecutive, critically ill comatose patients, hospitalized in a university hospital, medical-surgical intensive care unit, over a three year period. Nosocomial pneumonia developed in 53 (25%) patients after a mean of 8.1 days (range 3-31 days). Furthermore, there were five superinfections, raising the mean incidence to 28%. One patient developed secondary bacteraemia, and another two had septic shock. Fifteen (28%) patients from the pneumonia group died, and six of these deaths were considered to be directly related to nosocomial pneumonia. Identification of the causative agent, using the protected specimen brush technique, was possible in 42 episodes; in 10 (24%) of these cases more than one microorganism was isolated. Gram-positive cocci represented 53% of isolates, and Staphylococcus aureus accounted for 78% of all Gram-positive cocci, being the most frequent microorganism in this population. In conclusion, nosocomial pneumonia is a common complication of critically ill comatose patients. Its characteristic aetiological spectrum in this population should affect antibiotic prescription. Consequently, we suggest including antimicrobial drugs which are active against S. aureus in the empirical regimen until aetiological diagnosis is established.

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

“…We therefore recommend that future studies adopt a precise definition of coma to make results comparable among different centers. Gram-positive bacteria, particularly the Staphylococcus aureus, were the predominant cause of EOP in our study, a result confirming previous observations that gram-positive bacteria are the prevailing cause of pneumonia in critically ill neurological patients [5,9]. Antibiotic prophylaxis active against gram-positive bacteria should therefore be the preferred choice in such patients.…”

“…Altered consciousness is a recognized risk factor for VAP [5,6], and the occurrence of EOP in these patients is extremely high, accounting for 70% of all cases of pneumonia [7]. In a previously published paper we showed that the occurrence of EOP in patients with an ICU stay of >48 h was 32% [8], 44% in comatose patients and 29% in non-comatose patients (unpublished data).…”

“…Although this study is commonly quoted as being performed in patients with "structural coma" [7,10], it actually enrolled patients with various degrees of consciousness alteration, either comatose [Glasgow Coma Scale (GCS) score 8] [11] and non-comatose (GCS score 9-12) patients. Coma is a powerful predictor of morbidity and mortality in several clinical conditions [11,12,13], and comatose patients have depressed immune function [5,6], frequent upper airway colonisation on ICU admission [6,9], and altered or absent airway protective reflexes with risk of aspiration [12,14].…”