ABSTRACT
Hypoxia following suctioning has been well documented45,59,69,72 and incriminated in the causation of cardiac arrhythmias71 and bradycardia,72 although the latter may also be due to vagal stimulation.44 The adverse effect of suctioning on heart rate and oxygenation do not depend on the ventilation mode.47 Cerebral hemodynamics, as assessed by non-invasive near-infrared
(as evidenced by a decrease in the cerebral concentration of oxygenated hemoglobin and an increase in deoxygenated hemoglobin) during high-frequency oscillation (HFO) and conventional mechanical ventilation (CMV).47 The etiology of the hypoxia may be multifactorial, including removal from the oxygen source, suction-induced atelectasis and reflex bronchoconstriction.53 The length of time the patient is disconnected from the ventilator affects the degree of hypoxia, thus the suctioning time should be kept to a minimum. The maximum suctioning time for a term neonate should be 15 seconds and 7-10 seconds for a preterm infant. In many neonatal nurseries, adaptors are used which allow suctioning while the infant remains connected to the ventilator. This modification has been demonstrated to reduce the hypoxia associated with suctioning.38 In a crossover study involving 12 premature infants,8 closed compared to open suctioning was associated with a smaller deterioration in their oxygen saturation levels and a trend towards a faster recovery of heart rate and saturation levels.
