Ever since the first transcutaneous oxygen monitors came into use, we have known that endotracheal suctioning has undesirable effects on infants.1 Research in recent decades has shown us that this routine intervention, performed to help the infant, can result in arterial desaturation, hypoxemia, bradycardia, increased blood pressure, hypercapnia, and increased intracranial pressure.2
Investigators at the University of Arkansas for Medical Sciences measured physiologic parameters, using a fiberoptic sensor inserted into the umbilical artery catheter of very low birth-weight (VLBW) infants who were less than 1 week old to monitor pH, Paco2, PaO2, temperature, bicarbonate, base excess, and oxygen saturation in real time. Continuous measurements of right middle cerebral artery cerebral blood flow velocity (CBFv) were made using a transcranial Doppler ultrasound system.
Infants' endotracheal tubes were suctioned when clinically indicated, determined by the bedside nurse, based on oxygen desaturation, hypercapnia, clinical deterioration, visible secretions, coarse or decreased breath sounds, or decreased chest excursion. Suctioning was an open procedure without preoxygenation, preventilation, or sedation, and the catheter was passed no further than 0.5 cm beyond the end of the endotracheal tube. Sodium chloride solution was rarely used.
Middle cerebral artery CBFv increased during clincally indicated tracheal suctioning to a degree that agreed with previous research. However, in contrast with previous research, using continuous monitoring until all disturbed physiologic variables returned to baseline, these investigators discovered that these VLBW infants had late and prolonged elevations of CBFv. The infants' mean CBFv peaked at 6 minutes after tracheal suctioning and remained elevated for a worrisome 25 minutes after suctioning.2 This has implications not only for suctioning but for the planning and organization of nursing care of the VLBW infant.
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