Passive therapeutic hypothermia during ambulance and helicopter secondary neonatal transport in neonates with hypoxic brain injury: a 10-year retrospective survey

The Association Between Neonatal Intensive Care Unit Arrival Temperatures and Short-Term Outcomes of Neonates with Moderate and Severe Hypoxic-Ischemic Encephalopathy

Therapeutic hypothermia (TH) is the only treatment method that is known to reduce mortality and neurological sequela rates in newborns with moderate and severe hypoxic-ischemic encephalopathy (HIE). We aimed to evaluate the relationship between rectal temperatures measured upon arrival to our unit and short-term outcomes in newborns with HIE/TH. This was a retrospective study conducted between January 2022 and January 2023. The neonates were divided into three groups according to their rectal temperatures measured upon arrival at our unit as follows: Group 1) <33°C, Group 2) 33-34°C (group arriving at target temperature), and Group 3) >34°C. Short-term outcomes and mortality were compared between the groups. Group 1 consisted of 17 (19.8%) neonates, Group 2 consisted of 34 (39.5%) neonates, and Group 3 consisted of 35 (40.7%) neonates who had HIE and an indication for TH. Rectal temperature on arrival to the unit was not related to the rate of clinical convulsions, rates of abnormal attenuated electroencephalography and magnetic resonance imaging findings, rate of pulmonary hypertension, duration of mechanical ventilation and length of hospital stay. Although the mortality rate was 29% in Group 1, it was 3% and 6% in Groups 2 and 3, respectively (p = 0.016). No relationship was found between the rectal temperature upon arrival to the NICU and the short-term outcomes in HIE/TH neonates. However, the mortality rate in those who were overcooled was significantly higher compared with the other groups.

Short-term neurological injury in newborns infants with overcooling in passive hypothermia and transferred to reference hospital in Colombia

AIM

The aim of the study was to determine whether overcooling (temperature <33°C) during passive hypothermia when transporting neonates with perinatal asphyxia increased the risk of short-term neurological injury.

METHODS

A retrospective observational study was performed. Newborns transferred to the LaCardio neonatal unit between January 2021 and April 2022 with moderate and severe perinatal asphyxia and who received passive hypothermia during transport were included. A temperature of <33°C was considered overcooling. A composite outcome of neurological injury was defined by the presence of abnormalities on brain magnetic resonance imaging, video telemetry, seizure before discharge or both.

RESULTS

The study included 101 newborns. A total of 18 neonates had a temperature <33°C after transportation. Neurological injuries were present in 21.8% of the temperature <33°C group and 78.2% of the temperature ≥33°C group. Temperature <33°C at the end of transport (aOR 9.2, 95% CI 1.1-77.3) were associated with neurological injury before discharge from the unit.

CONCLUSION

During transportation, overcooling in neonates with asphyxia increases the risk of neurological injury before discharge from the neonatal unit. It is important to qualify the transport team with adequate training and equipment for therapeutic hypothermia.

Special Issue: Intensive Care for Critically Ill Neonates: Clinical Diagnosis and Treatment

Many physicians and researchers in the recent past have recognized the need to provide care and to study term and preterm infants when sufficient knowledge had not yet been attained, and to research how to approach and care for the most vulnerable children, i [...].

Neonatal Transport Safety Metrics and Adverse Event Reporting: A Systematic Review

OBJECTIVE

Neonatal transports are an essential component of regionalized medical systems. Neonates who are unstable after birth require transport to a higher level of care by neonatal transport teams. Data on adverse events on neonatal transports are limited. The aim of this study was to identify, evaluate, and summarize the findings of all relevant studies on adverse events on neonatal transports.

METHODS

We identified 38 studies reporting adverse events on neonatal transports from January 1, 2000, to December 31, 2019. The adverse events were distributed into 5 categories: vital sign abnormalities, laboratory value abnormalities, equipment challenges, system challenges, cardiopulmonary resuscitation, and transport-related mortality.

RESULTS

Most of the evidence surrounds vital sign abnormalities during transport (n = 28 studies), with hypothermia as the most frequently reported abnormal vital sign. Fourteen studies addressed laboratory abnormalities, 12 reported on events related to equipment issues, and 4 reported on system issues that lead to adverse events on transport. Of the 38 included studies, 12 included mortality related to transport as an outcome, and 4 reported on cardiopulmonary resuscitation during transport. There were significant variations in samples, definitions of adverse events, and research quality.

CONCLUSION

Adverse events during neonatal transport have been illuminated in various ways, with vital sign abnormalities most commonly explored in the literature. However, considerable variation in studies limits a clear understanding of the relative frequencies of each type of adverse event. The transport safety field would benefit from more efforts to standardize adverse event definitions, collect safety data prospectively, and pool data across larger care systems.

Effective Passive Cooling During Neonatal Transport

We retrospectively evaluated the rectal temperature of 297 hypoxic-ischemic encephalopathy (HIE) outborn newborns who were passive-cooling transported by Neonatal Emergency Transport Service (Genoa and Rome, Italy) at their arrival in Neonatal Intensive Care Unit. By a total of 1461 transports, 297 were for suspected HIE. Transferring suspected HIE newborn does not mean with certainty directing him/her to cooling treatment, but rather to monitoring and deepening in the hypothesis of starting hypothermia. This is the main reason why we have chosen 35°C (±0.5°C) as the temperature target to be maintained during transport. Our study demonstrated that 263/297 patients (88.55%) passively cooled during transport were within the target limit of 35°C (±0.5°C), whereas 15 newborns were at rectal temperature >35.5°C (5.05%) and 19 were <34.5°C (6.39%); no patients were <33°C. In our opinion, these are satisfactory results. Overcooling, failed temperature target, and unstable temperature values are the main problems claimed to occur during passive cooling in transport. We would like to conclude underlining that a well-experienced neonatal transport team can use passive cooling expecting appropriate performances.

Theoretical basis for the use of non-invasive thermal measurements to assess the brain injury in newborns undergoing therapeutic hypothermia

The aim of this paper is to propose a new non-invasive methodology to estimate thermogenesis in newborns with perinatal asphyxia (PA) undergoing therapeutic hypothermia (TH). Metabolic heat production (with respect to either a neonate’s body mass or its body surface) is calculated from the newborn’s heat balance, estimating all remaining terms of this heat balance utilising results of only non-invasive thermal measurements. The measurement devices work with standard equipment used for therapeutic hypothermia and are equipped with the Global System for Mobile Communications (GSM), which allows one to record and monitor the course of the therapy remotely (using an internet browser) without disturbing the medical personnel. This methodology allows one to estimate thermogenesis in newborns with perinatal asphyxia undergoing therapeutic hypothermia. It also offers information about instantaneous values of the rate of cooling together with values of remaining rates of heat transfer. It also shows the trend of any changes, which are recorded during treatment. Having information about all components of the heat balance one is able to facilitate comparison of results obtained for different patients, in whom these components may differ. The proposed method can be a new tool for measuring heat balance with the possibility of offering better predictions regarding short-term neurologic outcomes and tailored management in newborns treated by TH.