Comparison of a closed (Trach Care MAC) with an open endotracheal suction system in small premature infants

To determine whether ventilated, low birth weight infants treated with closed versus open tracheal suction in a neonatal intensive care unit (NICU) differ as to airway bacterial colonization, nosocomial pneumonia, bloodstream infection (BSI), incidence and severity of bronchopulmonary dysplasia (BPD), neonatal mortality, frequency of suction, reintubation, and nurse preference.

A total of 175 low birth weight infants (< or = 1250 gm) consecutively born (1997 to 1999), intubated, and ventilated in the delivery room were randomized on admission to the NICU to a closed (Trach Care MAC) or open suction group. Closed multi-use catheters were changed daily; open catheters were changed after every use. Two-pass endotracheal suctioning (both groups) was performed every 8 hours or as needed. Side-port connectors were not used; thus open suction required disconnection from ventilators. Tracheal aspirate cultures were obtained on admission and weekly thereafter. Nosocomial BSI (occurring after 48 hours of life) was documented by positive blood cultures. Radiographs taken before, during, and after tracheal aspirate cultures or BSIs were graded using a semiquantitative system for pneumonia and a modified score for BPD. Nurse preference regarding suction method was recorded.

Of the original 175 patients, 10 (5 from each group) died and 32 others (16 form each group) were extubated at or before 7 days of life. The study population comprised 67 patients in the closed group and 66 in the open group who were ventilated longer than 1 week. Groups were not statistically different in terms of demographic and clinical characteristics, such as birth weight (837 vs 876 gm), ventilation (27 vs 26 days), and length of stay (49 vs 40 days). Airway colonization with Gram-positive cocci occurred in the majority of patients by 2 weeks of life, regardless of group. A total of 39% of infants in the closed group and 44% of infants in the open group became airway colonized with Gram-negative bacilli; differences were statistically significant. No Gram-negative bacilli species was more likely to be associated with either suction. Nosocomial pneumonia was diagnosed in five patients from each group. Nosocomial BSIs occurred in six closed suction infants and five open suction infants. A comparable number of infants in each group developed severe BPD and were discharged from the hospital on oxygen. A total of 28% of closed suction patients and 27% of open suction patients died. Infants in the closed versus open group were suctioned on average 4.4 and 4.1 times per day and were reintubated 9.7 and 8.6 times per 100 ventilator days, respectively. A total of 40 of 44 NICU nurses considered closed suction to be easier to use, less time-consuming, and better tolerated by the patient.

Closed suction obviates the physiological disadvantage of ventilator disconnection without increasing the rate of bacterial airway colonization, frequency of endotracheal suction and reintubation, duration of mechanical ventilation, length of hospitalization, incidence of nosocomial pneumonia, nosocomial BSI, severity of BPD, and neonatal mortality. Although slightly more expensive, closed suction is perceived by nursing staff to be easier, less time-consuming, and better tolerated by small premature infants requiring mechanical ventilation for > or = 1 week.