It is known that the closed tracheal suction system (CTSS) produces less hemodynamic and gasometric deterioration than an open tracheal suction system (OTSS). Use is limited because no decrease in the incidence of ventilator-associated pneumonia (VAP) was found and also because it is more expensive. But, is daily periodic change of the CTSS necessary? The aim of this study was to analyze the incidence of VAP using a CTSS without periodic change versus an OTSS.
It is a prospective study of ICU patients from 1 January 2004 to 31 October 2004. Patients who required mechanical ventilation (MV) were randomized into two groups: one group was suctioned with CTSS without periodic change and another group with OTSS. An aspirate tracheal swab and a throat swab on admission and afterwards twice weekly were taken. VAP was classified based on throat flora in endogenous and exogenous samples. The statistical analysis was performed by chi-square test and Student's t test, and we took P < 0.05 as a significant difference.
There were no significant differences between both groups of patients (236 with CTSS without periodic change and 211 with OTSS) in age, sex, diagnosis groups, APACHE II score, number of aspirations per day and mortality. No significant differences were found in the percentage of patients who developed VAP (13.98% vs 14.02%), nor in the number of VAP per 1000 MV-days (14.13 vs 14.67). At the same time we did not find any differences in the percentage of patients who developed exogenous VAP (0.96% vs 0.88%). In the patients who needed MV during 24 hours or more, the aspiration cost was less expensive in the CTSS without periodic change group than in the OTSS group ($1.89 × 1.53 vs $2.45 × 0.71 per patient-day, P < 0.0001).
We conclude that in our study the CTSS without periodic change decreased the aspiration cost and did not modify the VAP incidence.