Saps II-Predicted Mortality in Ventilated Patients with Respiratory Acinetobacter baumannii Alone vs. Negative Culture

Li- Cher Loh,Jenny May- Geok Tong,Charity Tien-Jen Yii

doi:10.4172/2161-0703.1000105

Abstract

Background: In ventilated patients already critically ill, isolation of Acinetobacter baumannii from lower respiratory tract may have clinical importance and the differentiation between infection and colonization can be difficult. Aim: We sought to overcome the confounding element of critical illness by using Simplified Acute Physiology score (SAPS II) to predict mortality risk and comparing this in critically ill ventilated patients between those with A. baumannii alone and those entirely negative lower respiratory tract cultures. Methods: 138 eligible cases from an urban-based tertiary hospital intensive care unit (ICU) were retrospectively reviewed. Results: Between 43 patients with A. baumannii [mean age (SD): 47 (18.5) yrs; 65% male] and 95 matched patients with negative cultures [51 (17.5); 53%], median risks of hospital mortality were not significant different but the median (IQR 25-75 ) length of total hospital stay [19 (11-32) vs. 14 (9-21) days, p=0.022] and ICU [8 (4-19) vs. 7 (3-9), p=0.010] were significantly longer in A. baumannii group. Such findings occur irrespective of whether the underlying lungs were diseased or not and whether the isolates were resistant (except for cefepime-resistance). Conclusion:Isolation of lower respiratory tract A. baumannii alone in critically ill patients is no more likely to cause increased mortality risk than in those with negative culture, and prolonged ICU stay is likely responsible for the acquisition of A. baumannii .

Highlights

Acinetobacter baumannii, a ubiquitous aerobic Gram-negative bacterium with high propensity to multi-drug resistance is a worldwide concern because of its dramatic increase over the past few decades, in the setting of intensive care unit [1]
All eligible critically ill patients with documented single cultures of A. baumannii and those with entirely negative cultures of any pathogens deriving from lower respiratory tracts, ventilated in the intensive care unit (ICU) of our urban-based, 800-bed university teaching hospital, were retrospectively reviewed and relevant data collected by a single researcher (CTJY)
Data collected consisted of patient demographic characteristics and clinical details which included primary conditions that were being treated, presence of diseased lung, in vitro antimicrobial susceptibility of A. baumannii, SAPS II scores collected during the first 24 hrs of admission to ICU, observed hospital mortality and length of hospital stay (LOS)

Summary

Introduction

Acinetobacter baumannii, a ubiquitous aerobic Gram-negative bacterium with high propensity to multi-drug resistance is a worldwide concern because of its dramatic increase over the past few decades, in the setting of intensive care unit [1]. In critically ill ventilated patients, isolation of Acinetobacter baumannii from lower respiratory tract may have clinical importance and the differentiation between infection and colonization is usually difficult. The decision to eradicate becomes all the more important because of the implications in promoting multidrug resistance strains. This issue of colonization has added relevance in our region because of the increasing documentation of A. baumannii being community-acquired [5,6,7]. In ventilated patients already critically ill, isolation of Acinetobacter baumannii from lower respiratory tract may have clinical importance and the differentiation between infection and colonization can be difficult

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Conclusion