Head midline position for preventing the occurrence or extension of germinal matrix-intraventricular hemorrhage in preterm infants

Abstract

Background: Preterm birth is known to constitute the major risk factor for development of germinal matrix-intraventricular hemorrhage (GM-IVH). Head position may affect cerebral hemodynamics and thus may be involved indirectly in development of GM-IVH. Turning the head toward one side may functionally occlude jugular venous drainage on the ipsilateral side while increasing intracranial pressure and cerebral blood volume. Thus, it has been suggested that cerebral venous pressure is reduced and hydrostatic brain drainage improved if the patient is in supine midline position with the bed tilted 30°. The midline position might be achieved in the supine position and, with the use of physical aids, in the lateral position as well. Midline position should be kept, at least when the incidence of GM-IVH is greatest, that is, during the first two to three days of life.

Objectives: Primary objective To assess whether head midline position is more effective than any other head position for preventing or extending germinal matrix-intraventricular hemorrhage in infants born at ≤ 32 weeks' gestational age. Secondary objectives To perform subgroup analyses regarding gestational age, birth weight, intubated versus not intubated, and with or without GM-IVH at trial entry.

Search methods: We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8), MEDLINE via PubMed (1966 to September 19, 2016), Embase (1980 to September 19,.2016), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to September 19, 2016). We searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials.

Selection criteria: Randomized clinical controlled trials, quasi-randomized trials, and cluster-randomized controlled trials comparing placing very preterm infants in a head midline position versus placing them in 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 hemorrhage in a subgroup of infants. We planned to analyze horizontal (flat) versus head elevated positions separately for all body positions.

Data collection and analysis: We used standard methods of the Cochrane Neonatal Review Group. For each of the included trials, two review authors independently extracted data (e.g., number of participants, birth weight, gestational age, initiation and duration of head midline position, co-intervention with horizontal vs head elevated position, use of physical aids to maintain head position) and assessed risk of bias (e.g., adequacy of randomization, blinding, completeness of follow-up). The primary outcomes considered in this review are GM-IVH , severe IVH, and neonatal death.

Main results: Our search strategy yielded 2696 references. Two review authors independently assessed all references for inclusion. Two randomized controlled trials, for a total of 110 infants, met the inclusion criteria of this review. Both trials compared supine midline head position with the bed at 0° versus supine head rotated 90° with the bed at 0°. We found no trials that compared supine versus prone midline head position, and no trials that compared effects of head tilting. We found no significant differences in rates of GM-IVH (typical risk ratio [RR] 1.14, 95% confidence interval [CI] 0.55 to 2.35; typical risk difference [RD] 0.03, 95% CI -0.13 to 0.18; two studies, 110 infants; I² = 0% for RR and I² = 0% for RD), severe IVH (typical RR 1.57, 95% CI 0.28 to 8.98; typical RD 0.02, 95% CI -0.06 to 0.10; two studies, 110 infants; I² = 0% for RR and I² = 0% for RD), and neonatal mortality (typical RR 0.52, 95% CI 0.16 to 1.65; typical RD -0.07, 95% CI -0.18 to 0.05; two studies, 110 infants; I² = 28% for RR and I² = 44% for RD). Among secondary outcomes, we found no significant differences in terms of cystic periventricular leukomalacia (one study; RR 3.25, 95% CI 0.14 to 76.01; RD 0.04, 95% CI -0.07 to 0.15), retinopathy of prematurity (one study; RR 2.27, 95% CI 0.85 to 6.11; RD 0.25, 95% CI -0.02 to 0.53), and severe retinopathy of prematurity (one study; RR 2.73, 95% CI 0.31 to 24.14; RD 0.09, 95% CI -0.09 to 0.26). None of the included trials reported on the other specified outcomes of this review (i.e., cerebellar hemorrhage, brain magnetic resonance imaging abnormalities, impairment in cerebral hemodynamics, long-term neurodevelopmental outcomes, and major neurodevelopmental disability). The quality of evidence supporting these findings is limited owing to the imprecision of the estimates. We identified no ongoing studies.

Authors' conclusions: Given the imprecision of the estimate, results of this systematic review are consistent with beneficial or detrimental effects of a supine head midline position versus a lateral position and do not provide a definitive answer to the review question.

Figure 1

Study flow diagram.

Figure 2

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

Figure 3

Risk of bias summary: review authors' judgements about each risk of bias item for each included study.

Figure 4

Forest plot of comparison: 1 Supine midline head position with the bed at 0° versus supine head rotated 90° with the bed at 0°, outcome: 1.1 Intraventricular hemorrhage, any grade.

Figure 5

Forest plot of comparison: 1 Supine midline head position with the bed at 0° versus supine head rotated 90° with the bed at 0°, outcome: 1.2 Intraventricular hemorrhage, grade 3 to 4.

Figure 6

Forest plot of comparison: 1 Supine midline head position with the bed at 0° versus supine head rotated 90° with the bed at 0°, outcome: 1.3 Neonatal mortality.

Analysis 1.1

Comparison 1 Supine midline head position with the bed at 0° versus supine head rotated 90° with the bed at 0°, Outcome 1 Intraventricular hemorrhage, any grade.

Analysis 1.2

Comparison 1 Supine midline head position with the bed at 0° versus supine head rotated 90° with the bed at 0°, Outcome 2 Intraventricular hemorrhage, grade 3 to 4.

Analysis 1.3

Comparison 1 Supine midline head position with the bed at 0° versus supine head rotated 90° with the bed at 0°, Outcome 3 Neonatal mortality.

Analysis 1.4

Comparison 1 Supine midline head position with the bed at 0° versus supine head rotated 90° with the bed at 0°, Outcome 4 Cystic periventricular leukomalacia.

Analysis 1.5

Comparison 1 Supine midline head position with the bed at 0° versus supine head rotated 90° with the bed at 0°, Outcome 5 Retinopathy of prematurity, any stage.

Analysis 1.6

Comparison 1 Supine midline head position with the bed at 0° versus supine head rotated 90° with the bed at 0°, Outcome 6 Retinopathy of prematurity, ≥ stage 3.