Improved care and growth outcomes by using hybrid humidified incubators in very preterm infants

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).

Sterile water moisturizer of the skin of extremely low birth weight infants

OBJECTIVE

To assess the feasibility of sterile water application to the skin of the extremely low birth weight (ELBW) newborns in the first week of life and examine its effects on their skin integrity and outcomes.

DESIGN

Pilot randomized controlled trial.

SETTING

Open-bay, 18 bed Level III NICU in the Eastern United States.

PARTICIPANTS

Twenty-eight ELBW neonates. Two newborns expired, sixteen newborns remained in the intervention group and twelve newborns in the control group.

METHODS

ELBW neonates were either assigned to receive frequent sterile water wash to skin or not during care for the first week of life. Using the Neonatal Skin Condition Scale (NSCS), assessments were performed twice a day during the first week. Fluid intake, serum electrolytes, culture proven sepsis and other morbidities, and length of stay (LOS) were compared while controlling for confounding variables using multiple regression analysis.

RESULTS

There was no difference in the demographic or clinical characteristics between both groups. Sterile water wash application to skin was not associated with differences in skin health indices or fluid intake. However, it was associated with higher median sodium level and with early regression of bilirubin level when compared to controls.

CONCLUSION

Frequent skin washes with sterile water are feasible and safe. However, they may not be associated with improved skin integrity or fluid intake.

Humidification Practices of Extremely Preterm Neonates: A Clinical Survey

Extremely preterm neonates are at risk of morbidity and mortality related to their underdeveloped skin barrier. Humidified incubators are typically used in their care, but there is a paucity of literature to inform the standardization of specific evidence-based humidification practices in the NICU. A brief, voluntary, anonymous survey was distributed to our home institution and numerous national and international external institutions. Survey questions pertained to institutional humidification guidelines and were qualitatively analyzed. We received 89 responses from the home institution and 42 responses from the external institutions. Within the home institution, despite the presence of a guideline, individual practitioners reported varying practices in the starting levels of humidity and length of time spent in humidity. The results also demonstrated significant variability in individual humidification practices between the external institutions. There is no standard humidification guideline for extremely preterm neonates being cared for in the NICU. Further research is required to provide appropriate evidence on which to base clinical guidelines for the management of extremely preterm neonates to prevent morbidity and mortality in this population.

Optimising homeothermy in neonates: a systematic review and clinical guidelines from the French Neonatal Society

AIM

Thermal instability is harmful on the newborn infant. We sought to draw up practical guidelines on maintaining homeothermy alongside skin-to-skin contact.

METHODS

A systematic analysis of the literature identified relevant studies between 2000 and 2021 in the PubMed database. Selected publications were evaluated, and their level of evidence were graded, in order to underpin the development of clinical guidelines.

RESULTS

We identified 7 meta-analyses and 64 clinical studies with a focus on newborn infants homeothermy. Skin-to-skin contact is the easiest and most rapidly implementable method to prevent body heat loss. Alongside skin-to-skin contact, monitoring the newborn infant's body temperature with a target of 37.0°C is essential. For newborn infants <32 weeks of gestation, a skullcap and a polyethylene bag should be used in the delivery room or during transport. To limit water loss, inhaled gases humidification and warming is recommended, and preterm infants weighing less than 1600 g should be nursed in a closed, convective incubator. With regard to incubators, there are no clear benefits for single vs. double-wall incubators as well as for air vs. skin servo control.

CONCLUSION

Alongside skin-to-skin contact, a bundle of practical guidelines could improve the maintenance of homeothermy in the newborn infant.

Incubator humidity and temperature control in infants born at 22-23 weeks' gestation

BACKGROUND

Preterm infants, especially those born at ≤23 gestational weeks (GW), present with extremes in insensible water loss (IWL) and changes in water balance.

AIMS

To prevent water loss from the skin and achieve skin maturation without infection, we investigated transepidermal water loss (TEWL), IWL from the skin (IWL-s), and electrolyte balance with differences in high incubator humidity and temperature control from birth to postnatal 1 month in 22-23 GW and 24-25 GW infants.

STUDY DESIGN

Prospective cohort study.

SUBJECTS

Extremely preterm infants born at 22-23 GW (n = 11) and 24-25 GW (n = 11), admitted to the neonatal intensive care unit between September 2018 and October 2019.

OUTCOME MEASURES

Total fluid intake (TFI), fluid output volume, TEWL, IWL-s, and electrolyte balance were compared between the two groups with controlled incubator humidity and temperature, gradually decreasing the humidity and ambient temperature from 95% to 50% and from 37.0 to 34.0 °C, respectively, while maintaining the central body temperature at 36.5-37.5 °C.

RESULTS

TEWL and IWL-s between the 22-23 and 24-25 GW was not significantly different for infants at postnatal age. No significant difference in electrolyte imbalance was noted between the two groups, within the first 7 days. Differences in TEWL and IWL-s were eliminated with corresponding humidity and temperature adjustments.

CONCLUSIONS

Incubator humidity and temperature control should aid management of 22-23 GW infants to reduce IWL, facilitate skin maturation, and prevent infection.

Fluid management considerations in extremely preterm infants born at 22-24 weeks of gestation

Emerging data regarding the encouraging outcomes of extremely preterm infants from centers taking active approaches to the care of these infants have prompted dialogue regarding optimal medical management. Among the multitude of decisions providers make in caring for extremely premature infants is the prescribing of parenteral fluids. Surprisingly, there are limited data to guide evidenced-based approaches to fluid and electrolyte management in this population. Immaturity of renal function and skin barriers contribute to the impaired capacity of the preterm infant to maintain salt and water homeostasis. This perspective paper highlights developmental physiological properties of the kidney and skin, which the provider needs to understand to provide parenteral fluid therapy. Additionally, we provide recommendations for initial fluid and electrolyte management of the preterm infant based on novel data as well as the published literature.

Preterm Infant Incubator Humidity Levels: A Systematic Review

BACKGROUND

Numerous scholars have reported that inconsistent levels of incubator humidity in the neonatal intensive care unit (NICU) require attention. Evidence synthesis was needed to identify optimal incubator humidity levels and duration to decrease transepidermal water loss (TEWL) and the potential for infection.

PURPOSE

The purpose of this systematic review was to appraise and synthesize the evidence of preterm outcomes related to incubator humidity. The primary aim of this study was to determine how patient outcomes were impacted by incubator humidity levels and duration in premature infants born before 320/7 weeks cared for in the NICU.

METHODS/SEARCH STRATEGY

The foundation of this systematic review was the Joanna Briggs Institute method for systematic reviews. Mefford's theory of health promotion for the preterm infant was used to address the wholeness of the preterm infant's body system. Evidence was classified using the Johns Hopkins evidence-based practice levels and quality of evidence.

FINDINGS

Twelve studies met inclusion criteria. The evidence demonstrated that the practice of incubator humidity is warranted; however, it does not come without risks. Microbial growth was increased in high levels of incubator humidity. Unnecessary TEWL was prevented by lowering high levels of incubator humidity after the first week of life, improving skin barrier formation.

IMPLICATIONS FOR PRACTICE

Incubator humidity of 60% to 70% in the first week of life was effective in preventing TEWL in infants born 26 weeks or more.

IMPLICATIONS FOR RESEARCH

Future incubator humidity research is needed for infants born before 26 weeks.Video Abstract available athttps://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx?autoPlay=false&videoId=39.

Conservative Non-intervention Approach for Hemodynamically Significant Patent Ductus Arteriosus in Extremely Preterm Infants

While persistent patent ductus arteriosus (PDA) in preterm infants has been known to be associated with increased mortality and morbidities including bronchopulmonary dysplasia, and necrotizing enterocolitis, there is minimal evidence supporting their causal relationships, and most traditional medical and/or surgical treatments have failed to show improvements in these outcomes. As such, the pendulum has swung toward the conservative non-intervention approach for the management of persistent PDA during the last decade; however, the benefits and risks of this approach are unclear. In this mini review, we focused on whom, when, and how to apply the conservative non-intervention approach for persistent PDA, especially in extremely preterm infants.

Evidence-based skin care in preterm infants

Most guidelines on neonatal skin care emphasize issues pertaining to healthy, term infants. Few address the complex task of skin barrier maintenance in preterm, very preterm, and extremely preterm infants. Here, we provide an evidence-based review of the literature on skin care of preterm neonates. Interestingly, the stratum corneum does not fully develop until late in the third trimester, and as such, the barrier function of preterm skin is significantly compromised. Numerous interventions are available to augment the weak skin barrier of neonates. Plastic wraps reduce the incidence of hypothermia while semipermeable and transparent adhesive dressings improve skin quality and decrease the incidence of electrolyte abnormalities. Tub bathing causes less body temperature variability than sponge bathing and can be performed as infrequently as once every four days without increasing bacterial colonization of the skin. Topical emollients, particularly sunflower seed oil, appear to reduce the incidence of skin infections in premature neonates-but only in developing countries. In developed countries, studies indicate that topical petrolatum ointment increases the risk of candidemia and coagulase-negative Staphylococcus infection in the preterm population, perhaps by creating a milieu similar to occlusive dressings. For preterm infants with catheters, povidone-iodine and chlorhexidine are comparably effective at preventing catheter colonization. Further studies are necessary to examine the safety and efficacy of various skin care interventions in premature infants with an emphasis placed on subclassifying the patient population. In the interim, it may be beneficial to develop guidelines based on the current body of evidence.

Golden Hour Protocol for Preterm Infants: A Quality Improvement Project

BACKGROUND

Preterm infants are a vulnerable patient population, especially during the first hours of life. Hypothermia, hypoglycemia, and early-onset sepsis are common problems related to prematurity. Implementation of a Golden Hour protocol has been shown to improve outcomes for preterm infants.

PURPOSE

To evaluate the effectiveness of a Golden Hour protocol for infants born at less than 32 weeks' gestation on improving the admission process in a military care facility. Specific aims focused on temperature, time to initiation of intravenous (IV) fluids, time to administration of antibiotics, and time to close of the incubator top.

METHODS

A pre-/postdesign was used to compare outcomes from preimplementation to postimplementation. Predata were collected using electronic health record chart review and postdata were collected from the Neonatal Intensive Care Unit admission worksheet.

RESULTS

Although we did not find statistical significance, we found that more infants had a temperature greater than 36.5°C within 1 hour of birth and decrease in time to initiation of IV fluids and antibiotics from preimplementation to postimplementation, which is clinically significant. Time to close of the incubator top remained greater than 1 hour.

IMPLICATIONS FOR PRACTICE

Implementation of a Golden Hour protocol provides a guide to caring for preterm infants during the first hour of life to improve patient outcomes. Involvement of key stakeholders and staff education are key to successful implementation.

IMPLICATIONS FOR RESEARCH

Researchers should examine long-term outcomes related to implementation of a Golden Hour protocol in future studies. Future quality improvement projects should include the effectiveness of similar protocols and address possible barriers.

Failing to meet relative humidity targets for incubated neonates causes higher heat loss and metabolic costs in the first week of life

AIM

Frequent nursing procedures can modify a newborn infant's thermal environment when their incubator is opened. This study evaluated the impact of relative humidity (RH) on preterm infants in closed incubators and calculated their heat loss and additional metabolic cost.

METHODS

We studied 45 preterm infants born before 32 + 0 weeks, nursed at the neonatal intensive care unit at Amiens University Hospital, France from January 2009 to November 2011. Their body, skin and air temperatures and the incubator's RH were continuously recorded from day 1 to 8 of life, and the differences between the measured and target RH were calculated. Body heat loss (BHL) was also calculated.

RESULTS

On day one, the measured RH (68.7 ± 1.0%) was significantly lower than the target RH (75%, p < 0.05), but this difference, together with BHL (p < 0.001) and evaporative heat loss (p < 0.001), fell significantly over time (p < 0.05). The additional metabolic cost correlated with the difference between measured and target RH (p < 0.001).

CONCLUSION

RH from day 1 to 8 was below the recommended target value for preterm infants and resulted in high evaporative and greater total BHL and additional metabolic cost. The findings pose numerous challenges, including nursing care and incubator design.

Care of 500-1500 Gram Premature Infants in Hybrid Incubators

BACKGROUND

Although technological advances have improved devices used to maintain the temperatures of 500- to 1500-g infants, managing the thermal environment remains challenging.

PURPOSE

To evaluate the effects of 2 methods of thermal support provided by a hybrid incubator during routine care in the first week of life.

METHODS

This descriptive, comparative study evaluates changes in temperature, humidity, heart rate, and oxygen saturation in the incubator versus radiant warmer (canopy) modes of hybrid warmers using data downloaded from the incubator and the monitor. The impact of the Boost Curtain on temperature when opening the portholes during the incubator mode was also examined. Mixed-effects linear models and the log-rank test were used to analyze patient data to determine the effect of thermal support on temperature and humidity changes during care, as well as during the postcare period.

RESULTS

Entering the incubator through the portholes improved temperature control compared with using the canopy mode. The Boost Curtain resulted in an overall temperature stability and heat gain.

IMPLICATIONS FOR PRACTICE

Nurses caring for premature infants in hybrid incubators should minimize incubator openings and utilize portholes rather than the canopy whenever practical. The Boost Curtain should be used when opening the portholes during the incubator mode.

IMPLICATIONS FOR RESEARCH

Comparing time, accuracy, and tolerance of procedures in the canopy versus incubator modes would improve nurses' ability to determine the best approach for different clinical scenarios.

Mandatory Closure Versus Nonintervention for Patent Ductus Arteriosus in Very Preterm Infants

OBJECTIVE

To determine whether a nonintervention approach for treating hemodynamically significant patent ductus arteriosus (PDA) is associated with decreased mortality and/or morbidity compared with a mandatory closure approach in extremely low birth weight infants.

STUDY DESIGN

We reviewed the medical records of 178 infants of 23-26 weeks' gestational age with PDA, requiring ventilator treatment, and with hemodynamically significant PDA ≥2 mm in size. Mandatory closure was used during period I (July 2009 to December 2011, n = 81), and nonintervention was used during period II (January 2012 to June 2014, n = 97).

RESULTS

During period I, 64% of infants were first treated with indomethacin, and 82% were ultimately ligated surgically. During period II, no infant was treated with indomethacin and/or ligation. The average postnatal day of PDA closure was day 13 and day 44 during periods I and II, respectively. There was significantly more use of diuretics and fluid restriction during period II compared with period I. There was no difference in mortality or morbidities such as necrotizing enterocolitis or intraventricular hemorrhage. The incidence of bronchopulmonary dysplasia (BPD) and the propensity score adjusted OR of BPD were significantly lower during period II compared with period I.

CONCLUSIONS

Despite longer PDA exposure, nonintervention was associated with significantly less BPD compared with mandatory closure. Additional study is warranted to determine the benefits and risks of non-intervention for the hemodynamically significant PDA in extremely low birth weight infants.

Acute changes in fluid status affect the incidence, associative clinical outcomes, and urine biomarker performance in premature infants with acute kidney injury

BACKGROUND

During the first postnatal weeks, infants have abrupt changes in fluid weight that alter serum creatinine (SCr) concentration, and possibly, the evaluation for acute kidney injury (AKI).

METHODS

We performed a prospective study on 122 premature infants to determine how fluid adjustment (FA) to SCr alters the incidence of AKI, demographics, outcomes, and performance of candidate urine biomarkers. FA-SCr values were estimated using changes in total body water (TBW) from birth; FA-SCR = SCr × [TBW + (current wt. - BW)]/ TBW; where TBW = 0.8 × wt in kg). SCr-AKI and FA-SCr AKI were defined if values increased by ≥ 0.3 mg/dl from previous lowest value.

RESULTS

AKI incidence was lower using the FA-SCr vs. SCr definition [(23/122 (18.8 %) vs. (34/122 (27.9 %); p < 0.05)], with concordance in 105/122 (86 %) and discordance in 17/122 (14 %). Discordant subjects tended to have similar demographics and outcomes to those who were negative by both definitions. Candidate urine AKI biomarkers performed better under the FA-SCr than SCr definition, especially on day 4 and days 12-14.

CONCLUSIONS

Adjusting SCr for acute change in fluid weight may help differentiate SCr rise from true change in renal function from acute concentration due to abrupt weight change.

Nutritional strategy of early amino acid administration in very low birth weight infants

Relative to a fetus of the same gestational age, very low birth weight (VLBW) infants are more likely to be underfed and to undergo growth restriction during their early hospital stay. The current trend towards "early and aggressive" nutritional strategies in VLBW infants aims to overcome the early nutritional deficiency and thereby boost postnatal catch-up growth, simultaneously improving long-term neurodevelopmental outcomes. Although the minimum starting amino acid (AA) dose to prevent negative nitrogen balance is well established, the upper limit and the rate of increase of early AA doses are controversial. Most randomized controlled trials show that early and high-dose (target, 3.5 to 4.9 g/kg/day) AA regimens, with or without high nonprotein calories, do not improve long-term growth and neurodevelopment. High-dose AA supplementation may lead to early metabolic disturbances and excessive or disproportionate plasma AA levels, particularly in infants of very low gestational age. Further large studies are needed to clarify the optimal strategy for early administration of parenteral AA doses in VLBW infants.

Fluctuations in relative humidity provided to extremely low-birthweight infants (R1)

BACKGROUND

In extremely low-birthweight infants, the addition of relative humidity (RH) improves thermal stability, fluid and electrolyte balance. However, during routine care this microenvironment is frequently disturbed. The objective of this study was to determine the frequency, magnitude and direction of fluctuations in RH provided to extremely low-birthweight infants.

METHODS

All infants in our study had ambient temperature and RH continuously recorded for 48 h using a datalogger device (RH32S-C2). A clinically acceptable range for RH was defined as the set point ± 10%. A secondary analysis was performed to compare outcomes between infants that spent > 50% of the time out-of-range (OOR) or inside the range (IR). A P-value < 0.05 was significant.

RESULTS

A total of 20 infants were included. Important fluctuations were detected by the device with infants spending 40% and 14% of the time above and below the range, respectively. However, the RH set point did not differ from the mean levels measured over 48 h by the RH32S-C2 or the incubator. Infants in the OOR group spent significantly more time at values higher than the planned range when compared to IR infants.

CONCLUSION

Although significant fluctuations in RH above the desired range were detected in more than half of the infants, the average values were similar to the set points. Nevertheless, knowledge of these dynamic changes may help to optimize individualized care.