Effects of open vs. closed system endotracheal suctioning on cerebral blood flow velocities in mechanically ventilated extremely low birth weight infants.

BACKGROUND

Endotracheal (ET) suctioning causes cardiovascular side effects and may impair cerebral hemodynamics. Subjectively, these effects are worse if patients are disconnected from the ventilator (open system suctioning, OSS) than if they remain connected to the ventilator during suctioning (closed system suctioning, CSS). It is uncertain whether the response to ET suctioning is similar in conventionally (CV) and high frequency (HF) ventilated patients.

OBJECTIVES

To investigate if the mode of suctioning or of mechanical ventilation influences cerebral blood flow velocities (CBFVs) in extremely low birth weight (ELBW) infants.

METHODS

Transcranial Doppler sonography in the middle cerebral artery during OSS and CSS in CV and HF ventilated ELBW infants.

RESULTS

Forty-one measurements were performed in 19 infants within the first two weeks of life. Mean CBFVs decreased during suctioning from baseline 18.8 to 14.3 cm/s (-24%), increased thereafter to 24.7 cm/s (73%) and then returned to baseline (20.8 cm/s). Changes in CBFV were less pronounced in infants with higher baseline CBFVs. Heart rate decreased during ET suctioning and thereafter returned to baseline values. The alterations in CBFV and heart rate were both independent of the mode of ventilation or suctioning.

CONCLUSIONS

The mode of suctioning or ventilation does not influence CBFVs in ELBW infants.