Changes in energy expenditure in preterm infants during weaning: a randomized comparison of two weaning methods from an incubator

The role of weighing-bathing sequence and postmenstrual age in eliciting adaptive/maladaptive responses in very low birth weight preterm infants

PURPOSE

In the neonatal intensive care unit, preterm infants are exposed to several stressful stimuli. Inappropriate stimulation led to high risk for short- and long-term neurocognitive disabilities. This study aimed to evaluate whether the sequence of execution of weighing/bathing nursing procedures and postmenstrual age (PMA) have any effect on preterm infants' stress responses.

DESIGN AND METHODS

Prospective cross-sectional study on a sample of 21 preterm infants. Responses to the procedures were assessed using an observational sheet based on Als's Synactive Theory of Development. Autonomic and motor responses were scored according to five-point Likert scales. The order of execution of weighing/bathing nursing procedures and PMA were documented. Effects of weighing/bathing execution sequence and PMA on autonomic and motor response scores were analyzed by linear multiple regression analysis.

RESULTS

The sequence of execution had a significant effect on the autonomic score during weighing (p = .035), evidencing more stress when weighing was executed first. A higher level of stress response on the autonomic score during both weighing (p = .015) and bathing (p = .018) procedure was independently associated with a lower infant PMA.

CONCLUSIONS AND PRACTICE IMPLICATIONS

The real-time recognition of adaptive/maladaptive responses allows nurses to personalize their approach to preterm infants, taking into account PMA and adjusting the appropriate sequence of execution of weighing/bathing nursing procedures.

Transferring preterm infants into an open cot using a heated mattress at ≤ 1400 g

OBJECTIVE

The objective of this study is to evaluate the corrected age and weight that infants were transferred into an open cot using a heated mattress, in overall and within the subgroups of early (weight ≤ 1400 g) and standard transfer (weight > 1400 g).

DESIGN

Retrospective cohort study in a tertiary neonatal unit RESULTS: One hundred and thirty-five preterm infants were analysed. The mean weight of moving into an open cot was 1370 ± 167 g at a corrected age 33 ± 1.8 weeks. Eighty-three infants (61%) were transferred early at a mean weight 1276 ± 98 g compared with 52 infants of standard transfer with a mean weight 1522 ± 141 g. Infants of the early group had higher weight gain, were discharged earlier and had shorter length of stay.

CONCLUSIONS

Stable preterm infants can be safely moved to an open cot at < 33 weeks and weight ≤ 1400 g.

[Hospital discharge criteria for very low birth weight newborns]

Hospital discharge criteria for the pre-term newborn are mainly based on physiological competences (thermoregulation, respiratory stability, and feeding skills), although family support and ability to care for the baby, as well as a well-planned discharge are also cornerstones to ensure a successful discharge. In this article, the Committee of Standards of the Spanish Society of Neonatology reviews the current hospital discharge criteria in order for it to be useful as a clinical guide in Spanish neonatal units.

Relationship between energy expenditure and stress behaviors of preterm infants in the neonatal intensive care unit

PURPOSE

This research evaluated the relationship between behaviors and energy expenditure in preterm infants receiving nursing interventions.

DESIGN AND METHODS

This study was an explorative secondary data analysis from a previous study. The current study investigated energy expenditure calculated using heart rate-based energy expenditure-estimate across 500 repeated measures for 37 infants.

RESULTS

Research results indicate that preterm infants expend more energy when they show the following seven behaviors: grimace, sucking, diffusion squirm, fist, gape face, salute, and sneezing.

PRACTICE IMPLICATIONS

The interventions for preterm infants should be flexible, according to the infant's stress behaviors and conditions of energy expenditure.

Transfer of preterm infants from incubator to open cot at lower versus higher body weight

BACKGROUND

A key criterion for discharging preterm infants home from nurseries is their ability to maintain temperature once transferred from incubators to open cots. The timing of transfer is important given the preterm infant's immature thermoregulatory mechanisms.

OBJECTIVES

To determine the effects of body weight in transferring preterm infants from incubators to unheated open cots.

SEARCH STRATEGY

Electronic databases, the Cochrane Central Register of Controlled Trials, clinical trials registers and the abstracts of the Society for Pediatric Research were searched.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing transfer of preterm infants from incubators to unheated open cots at lower and higher body weights.

DATA COLLECTION AND ANALYSIS

Data collection and analysis was performed in accordance with the methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

Four eligible studies were identified. Two of the identified trials were assessed as having good methodological quality. Two studies reported daily weight gain (calculated as growth velocity); the lower body weight group had a significantly greater daily weight gain [pooled mean difference (MD) 2.66 (95% confidence interval (CI)1.37 to 3.95). One study reported a larger proportion of infants transferred at the higher body weight had an episode of low temperature in the first 72 hours; while no difference between the two groups was found in the proportion of infants experiencing cold stress post-transfer to discharge. Two studies report no difference between the two groups in requiring an overhead heater for temperature maintenance [pooled RR 1.43 (95% CI 0.35 to 1.18). No statistically significant difference was shown for proportion of infants returning to an incubator [three studies (N = 336) [pooled RR 1.78 (95% CI 0.77 to 4.08].Two studies report there was no statistically significant difference in time spent in an open cot post transfer to discharge; while one study found infants transferred at lower weights had a significantly reduced length of stay [MD -9.00 (95% CI -13.29 to -4.71), a second study found no differences between the two groups [MD 0.30 (95% CI -5.11 to 5.71). In these two studies not breastfeeding at discharge was not significantly different between the lower and higher body weight groups [pooled RR 1.02 (95% CI 0.69 to 1.51).

AUTHORS' CONCLUSIONS

Medically stable preterm infants can be transferred to unheated open cots at a lower body weight of 1600 grams without adverse effects on temperature stability or weight gain. Earlier transfer does not necessarily result in earlier discharge.

Cot-nursing versus incubator care for preterm infants

BACKGROUND

Preterm infants are usually nursed in incubators, but cot-nursing may provide an alternative. While there may be benefits of nursing preterm infants in open cots, there may be potential risks such as nosocomial infection caused by more handling due to easier access.

OBJECTIVES

To assess effects of cot-nursing versus incubator care on temperature control and weight gain in preterm infants.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of electronic databases including the Cochrane Central Register of Controlled Trials (The Cochrane Library), Oxford Database of Perinatal Trials, MEDLINE, CINAHL, and EMBASE, as well as previous reviews including cross references through November 2009.

SELECTION CRITERIA

All trials using random or quasi-random patient allocation in which infants receiving care in standard newborn cots were compared to infants managed in a conventional air heated incubator.

DATA COLLECTION AND ANALYSIS

The authors independently assessed trial quality and extracted data for the primary outcomes of temperature control and weight gain. Meta-analysis was conducted using a fixed-effect model.

MAIN RESULTS

Eleven potential studies were identified of which five, involving 247 infants, were included in this review. When compared to incubator care, cot-nursing resulted in no significant difference in mean body temperature (MD 0.02 degrees C; 95% CI -0.02 to 0.07, four trials), though the one trial that reported on episodes of hyperthermia found this to be statistically more common in the cot-nursing group (RR 1.48; 95% CI 1.04 to 2.09). There were no statistically significant differences in weight gain. In the cot-nursing group, fewer infants were breast fed on discharge (typical RR 0.74; 95% CI 0.48 to 1.14, three trials, 150 infants) and fewer infants died prior to hospital discharge (typical RR 0.59, 95% CI 0.28 to 1.25, four trials, 235 infants) but these results failed to reach statistical significance. The comparison of cot-nursing using a heated water-filled mattress versus incubator care, which included five trials and a total of 231 infants, produced similar results. Cot-nursing with warming of the nursery resulted in statistically significantly smaller weight gain during week one compared to the incubator group in one trial that involved 38 infants (MD -5.90 g/kg/day; 95% CI -11.13 to -0.67) but no significant difference was found for weeks two and three.

AUTHORS' CONCLUSIONS

Cot-nursing using a heated water-filled mattress has similar effects to incubator care with regard to temperature control and weight gain. Important clinical outcomes need to be investigated further using randomised controlled trials. This is especially the case in the situation of developing countries, where differences in these outcomes are likely to be encountered. As limited data is available on cot-nursing using a space-heated room, this method is not recommended as practice.

Effect of body weight on temperature control and energy expenditure in preterm infants

BACKGROUND

The purpose of this study was to compare resting energy expenditure (REE) in premature infants of different body weights during weaning from the incubator. We hypothesized that premature infants would respond to weaning from an incubator with an increase in REE, and that the increment would be larger in infants with lower body weights than in those with higher body weights.

METHODS

Stable preterm infants with body weights between 1800-2200 g were enrolled. REE was measured using indirect calorimetry at 1 hour before weaning and 3 hours after turning off the incubator. REE measurements from infants with higher body weight (2000-2200 g, Group A) were compared to those of infants with lower body weight (1800-2000 g, Group B).

RESULTS

A total of 22 patients were studied (10 in Group A and 12 in Group B). REE increased significantly after weaning in both groups (Group A: from 62 +/- 7 kcal/kg/day to 69 +/- 8 kcal/kg/day, p = 0.045 and Group B: from 65 +/- 5 kcal/kg/day to 70 +/- 7 kcal/kg/day, p = 0.001). However, there was no significant difference in REE increments between the two groups.

CONCLUSION

REE increased significantly in infants during weaning from an incubator. The increase in REE increment was similar in smaller (1800-2000 g) and larger (2000-2200 g) babies in this study. Weaning of preterm babies from an incubator may be safely started when their body weight reaches 1800 g.

Practice variation in the transfer of premature infants from incubators to open cots in Australian and New Zealand neonatal nurseries: results of an electronic survey

BACKGROUND

The incubator environment is essential for optimal physiological functioning and development of the premature infant but the infant is ultimately required to make a successful transfer from incubator to open cot in order to be discharged from hospital. Criteria for transfer lack a systematic approach because no clear, specific guideline predominates in clinical practice. Practice variation exists between continents, regions and nurseries in the same countries, but there is no recent review of current practices utilised for transferring premature infants from incubators to open cots.

OBJECTIVE

To document current practice for transferring premature infants to open cots in neonatal nurseries.

DESIGN

A descriptive, cross-sectional survey.

SETTINGS

Twenty-two neonatal intensive care units and fifty-six high dependency special care baby units located in public hospitals in Australia and New Zealand.

PARTICIPANTS

A sample of 78 key clinical nursing leaders (nurse unit managers, clinical nurse consultants or clinical nurse specialists) within neonatal nurseries identified through email or telephone contact.

METHODS

Data were collected using a web-based survey on practice, decision-making and strategies utilised for transferring premature infants from incubators to open cots. Descriptive statistics (frequencies and crosstabs) were used to analyse data. Comparisons between groups were tested for statistical significance using Chi-squared or Fisher's exact test.

RESULTS

Significant practice variation between countries was found for only one variable, nursing infants clothed (p=0.011). Processes and practices undertaken similarly in both countries include use of incubator air control mode, current weight criterion, thermal challenging, single-walled incubators and heated mattress systems. Practice variation was significant between neonatal intensive care units and special care baby units for weight range (p=0.005), evidence-based practice (p=0.004), historical nursery practice (p=0.029) and incubator air control mode (p=0.001). Differences in these variables were also found between nurseries in metropolitan and rural locations.

CONCLUSIONS

Practice variation exists however; many practices are uniformly performed throughout neonatal nurseries in Australian and New Zealand. Commonality was seen between countries and in nurseries with a neonatal intensive care unit. Variation was significant between neonatal intensive care units and special care baby units and nurseries in metropolitan and rural locations.