Interventions to prevent hypothermia at birth in preterm and/or low birthweight infants

Educating neonatal nurses in Brazil: a before-and-after study with interrupted time series analysis

BACKGROUND

Preterm birth contributes significantly to infant mortality and morbidity, including blindness from retinopathy of prematurity (ROP). Access to intensive neonatal care is expanding in many countries, but care is not always optimal, one factor being that nursing is often by inadequately trained nurse assistants.

OBJECTIVE

The aim of this study was to evaluate whether an educational package for nurses improves a range of outcomes including survival rates and severe ROP in 5 neonatal units in Rio de Janeiro, Brazil.

METHODS

The study design included an uncontrolled before-and-after study in 5 units, with interrupted time series analysis. Participatory approaches were used to develop a self-administered educational package for control of pain, oxygenation, infection, nutrition, and temperature and to improve supportive care ('POINTS of Care'). Educational materials and DVD clips were developed and training skills of nurse tutors were enhanced. There were two 1-year periods of data collection before and after a 3-month period of self-administration of the education package.

RESULTS

Overall, 74% of 401 nurses and nurse assistants were trained. A total of 679 and 563 infants were included in the pre- and post-training periods, respectively. Despite improvement in knowledge and nursing practices, such as the delivery and monitoring of oxygen, there was no change in survival (pre-training 80%, post-training 78.2%), severe ROP (1.6 vs. 2.8%), sepsis (11.3 vs. 12.3 cases per 1,000 infant days) or other outcomes. Outcomes worsened over the pre-intervention period but the change to an improvement after the intervention was not statistically significant. During the study period many trained staff left the units, but few were replaced.

CONCLUSIONS

Future studies need to focus on barriers to implementation, team building, leadership and governance, as well as the acquisition of knowledge and skills.

Feasibility and practical considerations for heating and humidifying gases during newborn stabilisation: an in vitro model

BACKGROUND

Gases for respiratory support at birth are typically 'cold and dry', which may increase the risk of hypothermia and lung injury.

OBJECTIVES

To determine the feasibility of using heated humidification from birth.

METHOD

A humidifier targeting 37°C, a manual-fill chamber and a Neopuff Infant T-piece resuscitator and circuit were attached to a face mask and a manikin. Recordings using 20 ml H2O for humidification and a flow of 10 l/min were undertaken. Temperature and relative humidity (RH) were recorded. Additional recordings were made, each with one alteration to baseline (50 ml H2O for humidification, auto-fill chamber, a flow of 8 l/min, addition of circuit extension piece, warmed humidification H2O, increased ambient temperature and targeting 31°C). The duration of heated humidification and the response to disconnecting the power were investigated.

RESULTS

The baseline circuit achieved 95% RH and 31°C in 3 min, >99% RH in 7 min and ≥35°C in 9 min. No circuit alterations resulted in faster gas conditioning. The extended length circuit and targeting 31°C reduced the maximum temperature achieved. A flow of 8 l/min resulted in slower heating and humidification. The baseline circuit delivered heated humidification for 39 min. Without power, the temperature and humidity fell below international standards in 3 min.

CONCLUSION

Rapid gas conditioning for newborn stabilisation is feasible using the experimental set-up, ≥20 ml H2O and a flow of 10 l/min. The circuit could be used immediately once switched on. Without power, conditioning is quickly lost. Investigation of the clinical effects of gas conditioning is warranted.

Randomized trial of plastic bags to prevent term neonatal hypothermia in a resource-poor setting

OBJECTIVES

Term infants in resource-poor settings frequently develop hypothermia during the first hours after birth. Plastic bags or wraps are a low-cost intervention for the prevention of hypothermia in preterm and low birth weight infants that may also be effective in term infants. Our objective was to test the hypothesis that placement of term neonates in plastic bags at birth reduces hypothermia at 1 hour after birth in a resource-poor hospital.

METHODS

This parallel-group randomized controlled trial was conducted at University Teaching Hospital, the tertiary referral center in Zambia. Inborn neonates with both a gestational age ≥37 weeks and a birth weight ≥2500 g were randomized 1:1 to either a standard thermoregulation protocol or to a standard thermoregulation protocol with placement of the torso and lower extremities inside a plastic bag within 10 minutes after birth. The primary outcome was hypothermia (<36.5°C axillary temperature) at 1 hour after birth.

RESULTS

Neonates randomized to plastic bag (n = 135) or to standard thermoregulation care (n = 136) had similar baseline characteristics (birth weight, gestational age, gender, and baseline temperature). Neonates in the plastic bag group had a lower rate of hypothermia (60% vs 73%, risk ratio 0.76, confidence interval 0.60-0.96, P = .026) and a higher axillary temperature (36.4 ± 0.5°C vs 36.2 ± 0.7°C, P < .001) at 1 hour after birth compared with infants receiving standard care.

CONCLUSIONS

Placement in a plastic bag at birth reduced the incidence of hypothermia at 1 hour after birth in term neonates born in a resource-poor setting, but most neonates remained hypothermic.

Application of plastic wrap to improve temperatures in infants born less than 30 weeks gestation: a randomized controlled trial

PURPOSE

The primary aim of the study was to evaluate whether the application of a plastic wrap immediately after birth is more effective than the standard care of temperature management for improving admission temperatures to the neonatal intensive care unit (NICU) in infants <30 weeks gestation.

DESIGN

A randomized controlled trial was conducted. Infants in the intervention group were transferred to a prewarmed radiant heater immediately after birth and encased in NeoWrap from the neck down without being dried. The infant's head was dried with a prewarmed towel and a hat added. The control group received usual care for the unit; the infant was transferred to the prewarmed radiant warmer and dried, and warm towels and a hat are then applied.

SAMPLE

A total of 92 infants were analyzed: 49 in the control group and 43 in the intervention group; 48 (52.2 percent) were <27 weeks gestation, and 44 (47.8 percent) were <30 weeks gestation. The infants' temperatures were assessed for two hours following admission.

Plastic bags for prevention of hypothermia in preterm and low birth weight infants

BACKGROUND AND OBJECTIVES

Hypothermia contributes to neonatal mortality and morbidity, especially in preterm and low birth weight infants in developing countries. Plastic bags covering the trunk and extremities of very low birth weight infants reduces hypothermia. This technique has not been studied in larger infants or in many resource-limited settings. The objective was to determine if placing preterm and low birth weight infants inside a plastic bag at birth maintains normothermia.

METHODS

Infants at 26 to 36 weeks' gestational age and/or with a birth weight of 1000 to 2500 g born at the University Teaching Hospital in Lusaka, Zambia, were randomized by using a 1:1 allocation and parallel design to standard thermoregulation (blanket or radiant warmer) care or to standard thermoregulation care plus placement inside a plastic bag at birth. The primary outcome measure was axillary temperature in the World Health Organization-defined normal range (36.5-37.5°C) at 1 hour after birth.

RESULTS

A total of 104 infants were randomized. At 1 hour after birth, infants randomized to plastic bag (n = 49) were more likely to have a temperature in the normal range as compared with infants in the standard thermoregulation care group (n = 55; 59.2% vs 32.7%; relative risk 1.81; 95% confidence interval 1.16-2.81; P = .007). The temperature at 1 hour after birth in the infants randomized to plastic bag was 36.5 ± 0.5°C compared with 36.1 ± 0.6°C in standard care infants (P < .001). Hyperthermia (>38.0°C) did not occur in any infant.

CONCLUSIONS

Placement of preterm/low birth weight infants inside a plastic bag at birth compared with standard thermoregulation care reduced hypothermia without resulting in hyperthermia, and is a low-cost, low-technology tool for resource-limited settings.

Neurological and developmental outcome in extremely preterm children born in England in 1995 and 2006: the EPICure studies

OBJECTIVE

To determine outcomes at age 3 years in babies born before 27 completed weeks' gestation in 2006, and to evaluate changes in outcome since 1995 for babies born between 22 and 25 weeks' gestation.

DESIGN

Prospective national cohort studies, EPICure and EPICure 2.

SETTING

Hospital and home based evaluations, England.

PARTICIPANTS

1031 surviving babies born in 2006 before 27 completed weeks' gestation. Outcomes for 584 babies born at 22-25 weeks' gestation were compared with those of 260 surviving babies of the same gestational age born in 1995.

MAIN OUTCOME MEASURES

Survival to age 3 years, impairment (2008 consensus definitions), and developmental scores. Multiple imputation was used to account for the high proportion of missing data in the 2006 cohort.

RESULTS

Of the 576 babies evaluated after birth in 2006, 13.4% (n=77) were categorised as having severe impairment and 11.8% (n=68) moderate impairment. The prevalence of neurodevelopmental impairment was significantly associated with length of gestation, with greater impairment as gestational age decreased: 45% at 22-23 weeks, 30% at 24 weeks, 25% at 25 weeks, and 20% at 26 weeks (P<0.001). Cerebral palsy was present in 83 (14%) survivors. Mean developmental quotients were lower than those of the general population (normal values 100 (SD 15)) and showed a direct relation with gestational age: 80 (SD 21) at 22-23 weeks, 87 (19) at 24 weeks, 88 (19) at 25 weeks, and 91 (18) at 26 weeks. These results did not differ significantly after imputation. Comparing imputed outcomes between the 2006 and 1995 cohorts, the proportion of survivors born between 22 and 25 weeks' gestation with severe disability, using 1995 definitions, was 18% (95% confidence interval 14% to 24%) in 1995 and 19% (14% to 23%) in 2006. Fewer survivors had shunted hydrocephalus or seizures. Survival of babies admitted for neonatal care increased from 39% (35% to 43%) in 1995 to 52% (49% to 55%) in 2006, an increase of 13% (8% to 18%), and survival without disability increased from 23% (20% to 26%) in 1995 to 34% (31% to 37%) in 2006, an increase of 11% (6% to 16%).

CONCLUSION

Survival and impairment in early childhood are both closely related to gestational age for babies born at less than 27 weeks' gestation. Using multiple imputation to account for the high proportion of missing values, a higher proportion of babies admitted for neonatal care now survive without disability, particularly those born at gestational ages 24 and 25 weeks.

Short term outcomes after extreme preterm birth in England: comparison of two birth cohorts in 1995 and 2006 (the EPICure studies)

OBJECTIVE

To determine survival and neonatal morbidity for babies born between 22 and 26 weeks' gestation in England during 2006, and to evaluate changes in outcome since 1995 for babies born between 22 and 25 weeks' gestation.

DESIGN

Prospective national cohort studies.

SETTING

Maternity and neonatal units in England.

PARTICIPANTS

3133 births between 22 and 26 weeks' gestation in 2006; 666 admissions to neonatal units in 1995 and 1115 in 2006 of babies born between 22 and 25 weeks' gestation.

MAIN OUTCOME MEASURES

Survival to discharge from hospital, pregnancy and delivery outcomes, infant morbidity until discharge.

RESULTS

In 2006, survival of live born babies was 2% (n=3) for those born at 22 weeks' gestation, 19% (n=66) at 23 weeks, 40% (n=178) at 24 weeks, 66% (n=346) at 25 weeks, and 77% (n=448) at 26 weeks (P<0.001). At discharge from hospital, 68% (n=705) of survivors had bronchopulmonary dysplasia (receiving supplemental oxygen at 36 weeks postmenstrual age), 13% (n=135) had evidence of serious abnormality on cerebral ultrasonography, and 16% (n=166) had laser treatment for retinopathy of prematurity. For babies born between 22 and 25 weeks' gestation from March to December, the number of admissions for neonatal care increased by 44%, from 666 in 1995 to 959 in 2006. By 2006 adherence to evidence based practice associated with improved outcome had significantly increased. Survival increased from 40% to 53% (P<0.001) overall and at each week of gestation: by 9.5% (confidence interval -0.1% to 19%) at 23 weeks, 12% (4% to 20%) at 24 weeks, and 16% (9% to 23%) at 25 weeks. The proportions of babies surviving in 2006 with bronchopulmonary dysplasia, major cerebral scan abnormality, or weight and/or head circumference <-2 SD were similar to those in 1995, but the proportion treated for retinopathy of prematurity had increased from 13% to 22% (P=0.006). Predictors of mortality and morbidity were similar in both cohorts.

CONCLUSION

Survival of babies born between 22 and 25 weeks' gestation has increased since 1995 but the pattern of major neonatal morbidity and the proportion of survivors affected are unchanged. These observations reflect an important increase in the number of preterm survivors at risk of later health problems.

Heating of gases during neonatal resuscitation: a bench study

AIM

Standard practice within the neonatal unit is to use heated humidified gas as it decreases respiratory complications in neonates requiring respiratory support. Using cold unhumidified gases during resuscitation could potentially cool the baby as well as exacerbate potential lung injury. We aimed to study the temperature and humidity aspects of using heated, humidified gas for neonatal resuscitation.

METHODS

A heated patient circuit was connected to a T-piece resuscitator via a humidifier. An oxygen flowmeter was set at 10 L/min. Temperature recordings at the humidifier chamber (T1), distal temperature probe (T2) and T-piece (T3) were taken over 20 min at 30s intervals. A humidity sensor was placed at T3.

RESULTS

Target temperatures were not reached. Time to 36°C (mean (sd)): T1 11.1 min (1.71); T3 11.6 min (1.77). T2 took 13.6 min (1.07) to reach 39°C. T1 and T3 were within ±1°C at 5.1 min (0.6). A biphasic relationship demonstrated the time lag between the temperatures of the heated patient circuit and the humidifier chamber. T3 strongly correlated to T1 when T1 is ≥28°C (r(2)=0.85). Humidity was difficult to measure and results were inferred from temperature recordings.

CONCLUSION

This in vitro test showed that heated, humidified gas is possible during neonatal resuscitation. Adequate time must be allowed for the humidifier chamber to warm to near optimal temperature. The patient circuit is initially heated faster than the humidifier chamber. The displayed T1 temperature correlates to the temperature at T3 at ≥28°C.

Hypothermia: novel approaches for premature infants

Hypothermia for hypoxic ischemic encephalopathy has recently permeated clinical practice for term infants. Speculation regarding a neuroprotective benefit of hypothermia for premature infants with HIE has been raised as a need for further research. Hypothermia for other indications including necrotizing enterocolitis with the hope of tissue preservation following injury is less well studied. A summary of evidence for hypothermia and premature infants is presented in this brief report.

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.