Preoxygenation for tracheal suctioning in intubated, ventilated newborn infants

Endotracheal suctioning for mechanically ventilated infants is routine practice in neonatal intensive care. However, this practice is associated with serious complications including lobar collapse, pneumothorax, bradycardia and hypoxemia. Increasing the inspired oxygen immediately prior to suction (preoxygenation) has been proposed as an intervention to minimise the risk of complications.

To compare the effects of preoxygenation with no preoxygenation for endotracheal suctioning on ventilated newborn infants. To conduct sub group analyses by i) different populations of newborn infants; by gestational age <30 weeks, <34 weeks and <37 weeks and by disease; infants with chronic lung disease compared to those without and; ii) by different techniques of endotracheal suctioning; with or without disconnection from the ventilator, increased mechanical ventilation, use of manual ventilation and chest wall vibrations or percussion.

The standard search strategy of the Neonatal Review Group was used. This included searches of electronic databases; Oxford Database of Perinatal Trials; Cochrane Controlled Trials Register (Cochrane Library Issue 1 2001); MEDLINE (1966 - April 2001); and CINAHL (1982-2001) using MeSH term infant-newborn and text terms oxygen* and suction*, preoxygenation, pre-oxygenation and premature and also previous reviews including cross references, abstracts in conferences and symposia proceedings, expert informants, journal hand searching in the English language.

Random or quasi random controlled trials of mechanically ventilated neonates in which endotracheal suctioning with preoxygenation was compared to suctioning without preoxygenation.

Standard methods of the Cochrane Collaboration and its Neonatal Review Group were used, including independent assessment of trial quality and extraction of data by the authors. Data were analysed using relative risk (RR) for dichotomous outcomes and mean difference (MD) for data measured on a continuous scale with the use of 95% confidence intervals. Meta-analysis was conducted using a fixed effects model.

One cross-over trial involving outcomes for 16 preterm neonates was included in this review. Preoxygenation, prior to an endotracheal suctioning procedure involving two suctions, resulted in a statistically significant reduction in infants with hypoxemia (TcPO2 <40 mmHg) at the end of the first suction (RR 0.18, 95% CI 0.05, 0.69), at the end of the second suction (RR 0.23, 95% CI 0.08, 0.66) and also at 120 seconds after the second suction (RR 0.10, 95% CI 0.01, 0.69). Mean TcPO2 was statistically significantly higher in the preoxygenation group at the end of the first suction (MD 25.00 mmHg, 95%CI 14.20, 35.80), second suction (MD 24.80, 95% CI 14.80, 34.80) and also at 120 seconds after the second suction (MD 29.10, 95% CI 14.96, 43.24). The time taken to return to baseline oxygenation status was shorter than the group not receiving preoxygenation (MD -2.12 minutes, 95% CI -3.82, -0.42).

No recommendations for practice can be confidently made from the results of this review. Although preoxygenation was shown to decrease hypoxemia at the time of suctioning, other clinically important short and longer-term outcomes including adverse effects were unable to be assessed. Further studies are needed to adequately assess the effects of this widely practiced procedure.