Review question
Does head midline position reduce the risk of intraventricular haemorrhage (i.e. bleeding in the brain) and mortality in very preterm infants?
Background
Intraventricular haemorrhage (i.e. bleeding in the brain) occurs in 25% of very low birth weight infants and may be caused by multiple factors. Head position may affect how the blood circulates within the brain and thus may be involved in development of intraventricular haemorrhage. Turning the head toward one side may limit return of blood in the veins of the same side and may increase pressure and the amount of blood within the brain. It has been suggested that this might be avoided if the patient is in supine (lying on the back) midline (central) position, especially during the first two to three days of life, when risk of intraventricular haemorrhage is greatest.
Study characteristics
We included three small studies comparing supine midline head position versus supine head rotated 90°. The search is up to date as of 12 September 2019.
Key results
This review of trials found too little evidence to show positive or negative effects of supine (lying on the back) midline head position for prevention of intraventricular haemorrhage (i.e. bleeding within the brain) in very preterm neonates. Mortality was lower in the supine midline head position, due to one study which compared the effects of head tilting (elevating the head of the incubator upward). We found no trials that compared supine (lying on the back) versus prone (lying on the stomach) midline head position.
Conclusions
Though one of the studies reported lower mortality in the infants with head central position lying on the back and with bed tilting, results of this systematic review are consistent with beneficial or detrimental effects of a supine head midline position and do not provide a definitive answer to the review question.
We found few trial data on the effects of head midline position on GM-IVH in very preterm infants. Although meta-analyses suggest that mortality might be reduced, the certainty of the evidence is very low and it is unclear whether any effect is due to cot tilting (a co-intervention in one trial). Further high-quality RCTs would be needed to resolve this uncertainty.
Head position during care may affect cerebral haemodynamics and contribute to the development of germinal matrix-intraventricular haemorrhage (GM-IVH) in very preterm infants. Turning the head toward one side may occlude jugular venous drainage while increasing intracranial pressure and cerebral blood volume. It is suggested that cerebral venous pressure is reduced and hydrostatic brain drainage improved if the infant is cared for in the supine ‘head midline’ position.
To assess whether head midline position is more effective than other head positions for preventing (or preventing extension) of GM-IVH in very preterm infants (< 32 weeks’ gestation at birth).
We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 9), MEDLINE via PubMed (1966 to 12 September 2019), Embase (1980 to 12 September 2019), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 12 September 2019). We searched clinical trials databases, conference proceedings, and reference lists of retrieved articles.
Randomised controlled trials (RCTs) comparing caring for very preterm infants in a supine head midline position versus a prone or lateral decubitus position, or undertaking a strategy of regular position change, or having no prespecified position. We included trials enrolling infants with existing GM-IVH and planned to assess extension of haemorrhage in a subgroup of infants. We planned to analyse horizontal (flat) versus head elevated positions separately for all body positions.
We used standard methods of Cochrane Neonatal. For each of the included trials, two review authors independently extracted data and assessed risk of bias. The primary outcomes were GM-IVH, severe IVH, and neonatal death. We evaluated treatment effects using a fixed-effect model with risk ratio (RR) for categorical data; and mean, standard deviation (SD), and mean difference (MD) for continuous data. We used the GRADE approach to assess the certainty of evidence.
Three RCTs, with a total of 290 infants (either < 30 weeks' gestational age or < 1000 g body weight), met the inclusion criteria. Two trials compared supine midline head position versus head rotated 90° with the cot flat. One trial compared supine midline head position versus head rotated 90° with the bed tilted at 30°. We found no trials that compared supine versus prone midline head position.
Meta-analysis of three trials (290 infants) did not show an effect on rates of GM-IVH (RR 1.11, 95% confidence interval (CI) 0.78 to 1.56; I² = 0%) and severe IVH (RR 0.71, 95% CI 0.37 to 1.33; I² = 0%). Neonatal mortality (RR 0.49, 95% CI 0.25 to 0.93; I² = 0%; RD −0.09, 95% CI −0.16 to −0.01) and mortality until hospital discharge (typical RR 0.50, 95% CI 0.28 to 0.90; I² = 0%; RD −0.10, 95% CI −0.18 to −0.02) were lower in the supine midline head position. The certainty of the evidence was very low for all outcomes because of limitations in study design and imprecision of estimates. We identified one ongoing study.