Clinical experience and incidence of ventilator-associated pneumonia using closed versus open suction-system

Studies have shown a decreasing ventilator-associated pneumonia (VAP) incidence after prophylactic interventions bundles. The use of closed suction systems (CSS) has been suggested beneficial as a prophylactic measure.

To investigate the effects of a CSS on VAP incidence, suction circuit contamination and adverse events (AEs) compared to an open suction system (OSS) approach in a general mixed intensive care unit (ICU).

Adult patients on mechanical ventilation were consecutively included. Data were collected during four 1-month periods where CSS and OSS were used on an alternating basis. Airway cultures were obtained at intubation, after 72 h and every Monday. After changing CSS and at extubation, the catheter tip was cultured. AEs and desaturation events during suction were monitored.

Descriptive analysis and differences between the groups were analysed using comparative methods.

No differences in airway colonization at admission between the groups were detected (Table 2). The CSS group had a higher Simplified Acute Physiology Score (SAPS) III and also a non-significant increase in VAP incidence. Positive cultures were obtained in 50% of all the retrieved CSS catheters. There was no inter-patient contamination in either group. Six AEs versus one (CSS/OSS) related to tube-occlusion and secretion clogging was seen. Desaturations at suctioning were rare in both groups.

No beneficial effects were seen on VAP incidence or inter-patient contamination compared to OSS. A high frequency of circuit contamination in the CSS group paralleled with experienced secretions clearance problems seem unfavourable and in concordance with previous studies.