A comparison of two airway suctioning frequencies in mechanically ventilated, very-low-birthweight infants.

INTRODUCTION

Endotracheal suctioning of mechanically ventilated, very-low-birthweight infants for removal of respiratory secretions can be associated with morbidity. Routine endotracheal suctioning is inadvisable, but the safe minimum endotracheal suctioning frequency for prevention of airway obstruction has not been determined.

HYPOTHESIS

Decreasing suctioning frequency from every 4 hours to every 8 hours (plus as needed) would have no clinically important effect on the primary outcomes (nosocomial bloodstream infection [BSI], ventilator-associated pneumonia [VAP], and bacterial airway colonization) or secondary outcomes (reintubation rates, need for postural drainage, severity of bronchopulmonary dysplasia [BPD], neonatal mortality, duration of mechanical ventilation, and duration of hospitalization).

METHODS

We conducted a sequential retrospective study of 90 very-low-birthweight infants who were mechanically ventilated for longer than 7 days and who underwent endotracheal suctioning every 4 hours (plus as needed) and 90 similar infants who underwent endotracheal suctioning every 8 hours (plus as needed). Two-pass endotracheal suctioning used during the study period required predetermined measurement of the suction catheter and prior instillation of saline.

RESULTS

The 2 treatment groups were similar in demographic and clinical characteristics, including survival (90% and 85%), age at time of death (28 and 33 d), mean birthweight (926 and 934 g), gestational age (27 and 27 wk), duration of ventilation (29 and 27 d), and duration of stay (55 and 53 d). Regardless of suctioning frequency, airway colonization with Gram-positive cocci occurred in the majority of patients by 2 weeks of life. Forty-three percent of the infants suctioned every 4 hours and 44% of those suctioned every 8 hours became airway colonized with Gram-negative bacilli. No Gram-negative bacilli species was more likely to be associated with either treatment group. VAP was diagnosed in 5 of the infants suctioned every 4 hours and in 9 of the infants suctioned every 8 hours. Nosocomial BSI occurred in 18 of the infants suctioned every 4 hours and in 21 of the infants suctioned every 8 hours. The difference in incidence of VAP and BSI was due to a epidemic that started before the change in suctioning frequency. During hospitalization, approximately one fourth of the patients in each group required postural drainage and were reintubated 11 and 10 times per 100 ventilator days, respectively. A comparable number of infants in each group developed severe BPD and were discharged home on oxygen. Suctionings per patient per ventilator day were 6 for the group suctioned every 4 hours and 4 for the group suctioned every 8 hours (p < 0.01).

CONCLUSIONS

A low-frequency suctioning regimen (every 8 hours plus as needed) can be implemented without increasing the incidence of nosocomial BSI, VAP, bacterial airway colonization, frequency of reintubation, need for postural drainage, severity of BPD, neonatal mortality, duration of mechanical ventilation, or duration of hospitalization. Although the minimum suctioning frequency for removal of unwanted respiratory secretions is yet to be established, a substantial reduction in endotracheal suctioning frequency appears to be safe.