Double wall versus single wall incubator for reducing heat loss in very low birth weight infants in incubators

Thermoregulation, incubator humidity, and skincare practices in appropriate for gestational age ultra-low birth weight infants: need for more evidence

BACKGROUND

Although not universal, active care is being offered to infants weighing < 500 g at birth, referred to as ultra-low birth weight (ULBW) infants appropriate for gestational age. These infants have the greatest risk of dying or developing major morbidities. ULBW infants face challenges related to fluid and heat loss as well as skin injury in the initial days of life from extreme anatomical and physiological immaturity of the skin. Although there is an emerging literature on the outcomes of ULBW infants, there is a paucity of evidence to inform practice guidelines for delivering optimal care to this cohort of infants.

DATA SOURCES

A comprehensive review of the literature was performed using the PubMed and Embase databases. Searched keywords included "thermoregulation or body temperature regulation", "incubator humidity", "skin care", "infant, extremely low birth weight" and "ultra-low birth weight infants".

RESULTS

Evidences for thermoregulation, incubator humidity, and skincare practices are available for preterm infants weighing < 1500 g at birth but not specifically for ULBW infants. Studies on thermoregulation, incubator humidity, or skincare practices had a small sample size and did not include a sub-group analysis for ULBW infants. Current practice recommendations in ULBW infants are adopted from research in very and/or extremely low birth weight infants.

CONCLUSIONS

This narrative review focuses on challenges in thermoregulation, incubator humidity, and skincare practices in ULBW infants, highlights current research gaps and suggests potential developments for informing practices for improving health outcomes in ULBW infants. Video abstract (MP4 1,49,115 kb).

Scoping review of systematic reviews of nursing interventions in a neonatal intensive care unit or special care nursery

AIM(S)

To identify, synthesise and map systematic reviews of the effectiveness of nursing interventions undertaken in a neonatal intensive care unit or special care nursery.

DESIGN

This scoping review was conducted according to the JBI scoping review framework.

METHODS

Review included systematic reviews that evaluated any nurse-initiated interventions that were undertaken in an NICU or SCN setting. Studies that reported one or more positive outcomes related to the nursing interventions were only considered for this review. Each outcome for nursing interventions was rated a 'certainty (quality) of evidence' according to the Grading of Recommendations, Assessment, Development and Evaluations criteria.

DATA SOURCES

Systematic reviews were sourced from the Cochrane Database of Systematic Reviews and Joanna Briggs Institute Evidence Synthesis for reviews published until February 2023.

RESULTS

A total of 428 articles were identified; following screening, 81 reviews underwent full-text screening, and 34 articles met the inclusion criteria and were included in this review. Multiple nursing interventions reporting positive outcomes were identified and were grouped into seven categories. Respiratory 7/34 (20%) and Nutrition 8/34 (23%) outcomes were the most reported categories. Developmental care was the next most reported category 5/34 (15%) followed by Thermoregulation, 5/34 (15%) Jaundice 4/34 (12%), Pain 4/34 (12%) and Infection 1/34 (3%).

CONCLUSIONS

This review has identified nursing interventions that have a direct positive impact on neonatal outcomes. However, further applied research is needed to transfer this empirical knowledge into clinical practice.

IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE

Implementing up-to-date evidence on effective nursing interventions has the potential to significantly improving neonatal outcomes.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public involvement in this scoping review.

A Simplification and Implementation of Random-effects Meta-analyses Based on the Exact Distribution of Cochran’s Q

Background: The random-effects (RE) model is the standard choice for meta-analysis in the presence of heterogeneity, and the stand ard RE method is the DerSimonian and Laird (DSL) approach, where the degree of heterogeneity is estimated using a moment-estimator. The DSL approach does not take into account the variability of the estimated heterogeneity variance in the estimation of Cochran’s Q. Biggerstaff and Jackson derived the exact cumulative distribution function (CDF) of Q to account for the variability of Ť 2.

Objectives: The first objective is to show that the explicit numerical computation of the density function of Cochran’s Q is not required. The second objective is to develop an R package with the possibility to easily calculate the classical RE method and the new exact RE method.

Methods: The novel approach was validated in extensive simulation studies. The different approaches used in the simulation studies, including the exact weights RE meta-analysis, the I 2 and T 2 estimates together with their confidence intervals were implemented in the R package metaxa.

Results: The comparison with the classical DSL method showed that the exact weights RE meta-analysis kept the nominal type I error level better and that it had greater power in case of many small studies and a single large study. The Hedges RE approach had inflated type I error levels. Another advantage of the exact weights RE meta-analysis is that an exact confidence interval for T 2is readily available. The exact weights RE approach had greater power in case of few studies, while the restricted maximum likelihood (REML) approach was superior in case of a large number of studies. Differences between the exact weights RE meta-analysis and the DSL approach were observed in the re-analysis of real data sets. Application of the exact weights RE meta-analysis, REML, and the DSL approach to real data sets showed that conclusions between these methods differed.

Conclusions: The simplification does not require the calculation of the density of Cochran’s Q, but only the calculation of the cumulative distribution function, while the previous approach required the computation of both the density and the cumulative distribution function. It thus reduces computation time, improves numerical stability, and reduces the approximation error in meta-analysis. The different approaches, including the exact weights RE meta-analysis, the I 2 and T 2estimates together with their confidence intervals are available in the R package metaxa, which can be used in applications.

Double wall versus single wall incubator for reducing heat loss in very low birth weight infants in incubators

BACKGROUND

Studies have shown improved survival of newborn infants maintained in the thermoneutral range. The concept of an incubator with additional insulation, a double plexiglass wall, is appealing for very low birth weight infants as it may help to provide a thermoneutral environment.

OBJECTIVES

To assess the effects of double walled incubator versus a single wall incubator on insensible water loss, rate of oxygen consumption, episodes of hypothermia, time to regain birth weight, duration of hospitalization and infant mortality in premature infants.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of electronic databases: Oxford Database of Perinatal Trials, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006), MEDLINE (1966 - 2006), EMBASE, previous reviews including cross references, abstracts, conference and symposia proceedings, expert informants in all published languages, and CINAHL (1982 - 2006).

SELECTION CRITERIA

Only studies using random or quasi-random methods of allocation were considered for this review. Eligible studies assessed at least one of the outcome variables identified as important to this topic.

DATA COLLECTION AND ANALYSIS

Independent data extraction and quality assessment of included trials was conducted by the review authors. Data were analyzed using generic inverse variance methodology and weighted mean difference (WMD). Results are presented with 95% confidence intervals. Meta-analysis was undertaken using a fixed effect model.

MAIN RESULTS

Three studies met the criteria. Four other studies were excluded, as they did not compare double versus single wall incubators (details of the studies are given in the included and excluded studies section). Double wall incubators have the advantage of decreasing heat loss, decreasing heat production and decreasing radiant heat loss when compared to single wall incubators. There is also the advantage of reduced oxygen consumption. A minimal increase in conductive heat loss was noted when compared to single wall incubators. All of these effects are small and do not support the proposition that double wall incubators have a beneficial effect on long term outcomes including mortality or the duration of hospitalization.

AUTHORS' CONCLUSIONS

Although it appears that caring for extremely small infants in double wall incubators may theoretically result in shorter hospitalization and may have metabolic advantages, this review was unable to find any data in the literature to support or refute this hypothesis. The studies do not provide any evidence that the small decrease in heat loss improves clinical outcome. Therefore, the available data is insufficient to directly guide clinical practice.