A Need for Early Tracheostomy (Trach) Placement: Differences in Incidence of Ventilator-Associated Pneumonia (VAP) and Pathogens with Duration of Ventilation

Background:   VAP in our intensive care units have been decreased, but not eliminated, with the use of prevention bundles.  There are significant differences in duration of ventilation before trach placement across intensive care units (ICU).

Objective:   To evaluate the incidence and pathogens associated with VAP in patients (pt) who undergo trach placement at differing time periods, compared to patients who were ventilated with endotracheal tube (ETT) alone.

Methods:  A retrospective cohort study of ventilated pts in 5 adult ICUs was performed from 7/1/06 to 6/30/09.  Pts on ventilator < 48 hours or who had a trach present on admission were excluded.  Pts were divided into those who had a trach placed (trach) and those who had only ETT.  Duration of ETT to trach placement was stratified as: < 7 days, trach within 7-14 days, trach day 15 or longer.  Duration of ETT ventilation was stratified as: ETT for < 7 days, ETT for 7–14 days, ETT for 15 or more days.  VAPs occurring 7 or more days after intubation were included and were confirmed using NHSN definitions.

Results:  During the study period, there were 33,937 ventilator (vent) days and 140 VAPs in the 5 ICUs (4.1 VAP/1000 vent days), of which, 73 occurred in pts who underwent trach placement.  The incidence of VAP in pts trached < 7 days was 4.4/100 pts (3.3 VAP/1000 vent days).  VAP incidence in pts trached 7-14 days was 15.5/100 pts (7.1 VAP/1000 vent days).  In pts trached 15 days or longer, VAP incidence was 23.2/100 pts (6.1 VAP/1000 vent days).  (p=<0.0001)  In pts trached < 7 days, the average duration of ventilation was 13.2 days (range 2-68 days).  In pts trached 7-14 days the average duration of ventilation was 26.4 days (range 8-231 days).  Pts trached 15 days or longer had an average duration of ventilation of 38.6 (range 17-280 days). 

In pts with ETT only, there were 31 VAPs.  The incidence of VAP was:  0.04/100 pts, in ETT < 7days; 2.7/100 pts in ETT 7-14 day; and 11/100 pts in ETT 15 days or longer.  (p=<0.0001).

VAP in patients undergoing trach placement were associated with the following organisms:  In the trach < 7 day group, all 10 (100%) were gram-negative (GN) organisms.  In those trached 7-14 days, organisms were: 54 (93%) GN; 3 (5%) gram-positive (GP); 1 (2%) Candida; and 1 (2%) had no organism identified.  In the group trached 15 days or longer, organisms included: 21 (78%) GN; 3 (11%) GP; and 3 (11%) had no organism identified.

Conclusions:  In our study, pts with trach placement within the first 7 days of ventilation had the lowest incidence of VAP; the incidence of VAP increased with increasing duration of ventilation before trach placement.  As the time to trach is extended, the VAP pathogen patterns changed from being exclusively gram-negative to 13% caused by other organisms.  Physicians should consider early trach for pts requiring long-term ventilation.