Improved prognosis in severely hypothermic newborn infants treated by rapid rewarming

doi:10.1016/S0022-3476(84)80031-1

The Journal of Pediatrics

Volume 105, Issue 3, September 1984, Pages 470-474

https://doi.org/10.1016/S0022-3476(84)80031-1 Get rights and content

We introduced a rapid rewarming technique as part of standard therapy in 16 newborn infants with effects of severe environmental hypothermia. On admission. mean rectal temperature was 31.0±2.7°C, mean gestational age was 33.4±4.5 weeks, and mean birth weight was 1.76±0.71 kg. Thirteen infants were admitted within 30 hours of delivery, and the remainder at 2 to 3 weeks of age. Infants were rewarmed under a radiant warmer. The mean time required to reach a rectal temperature of 36.5°C was 3.96±2.37 hours. Major medical entities encountered included thrombocytopenia (eight patients), metabolic acidosis (eight), respiratory distress (eight), renal failure (six), apnea (four), patent ductus arteriosus (four), seizures (four), intracranial hemorrhage (three), infection (three), and necrotizing enterocolitis (two). No complications could be attributed to the rapid rewarming technique. Of three infants who died, all weighed <1.25 kg at birth. This 81% survival is in contrast to the high mortality (25% to 50%) noted previously among infants treated by gradual rewarming.

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Cited by (31)

Unrecognized platelet physiology is the cause of rewarming deaths in accidental hypothermia and neonatal cold injury
2021, Medical Hypotheses
Citation Excerpt :
Bleeding is commonly found in neonatal cold injury series. Platelet levels of less than 50,000/mm2 were found in 50% of 16 babies with severe hypothermia, 5 of whom had seizures or intracranial haemorrhage [6]. Haemorrhagic manifestations including petechiae, vomiting of altered blood, melena and pre agonal bleeding from the nose and mouth occurred.
The lack of improvement in prognosis of accidental hypothermia and neonatal cold injury suggests that a major cause of mortality has not been appreciated.
To show that thrombocytopenia that deepens on rewarming under certain conditions is that missing factor.
Below 34 °C the first stage of aggregation is accentuated, the platelets are more sensitive to ADP and aggregation studies show an increased response “first stage hyper aggregation”. We have confirmed that the irreversible second stage of platelet aggregation does not occur below 34 °C. On rewarming, the first stage of aggregation is followed by disaggregation. When platelets are warmed to 34 °C the potential exists for the platelets to undergo an irreversible second stage of aggregation “second stage platelet hyper aggregation” that can cause a further drop in platelet count and a bleeding diathesis. This only occurs if the platelets have been sufficiently primed when cold and may not be appreciated if platelet counts are not followed.
This thesis explains many other open questions. Why has the overall prognosis remained without improvement over the last half century? Why hypothermic cardiac surgery is free of this problem? Why the depth of hypothermia is alone not prognostic? Has following platelet counts been associated with improved prognosis? Why cardiac arrest does not affect prognosis? Why some patients die suddenly after recovering from hypothermia? Why are so many different rewarming techniques used? Why is the prognosis better in hypothermic suicide attempts? What is the pathophysiological explanation for reversible sequestration of platelets to the liver and spleen in hypothermia? Is DIC (diffuse intravascular coagulation) a problem in hypothermia? And how this new approach could improve prognosis?
Prognosis can be improved by following platelet counts during rewarming. In patients with prolonged hypothermia, this will show a life-threatening drop in such counts easily treated by platelet infusion.
Association of Rewarming Rate on Neonatal Outcomes in Extremely Low Birth Weight Infants with Hypothermia
2015, Journal of Pediatrics
Citation Excerpt :
Furthermore, a too quick increase of skin temperature may result in vasodilatation, which may lead to pooling of the blood, with a subsequent decrease in blood pressure. However, because of the persisting high mortality in infants treated with slow rewarming strategy, other studies have considered a rapid rewarming approach9,14,15 that is the recommended therapy in adults with hypothermia.23,24 In addition, rapid rewarming improved survival rate in rabbits with hypothermia.25
To explore the possible association between rewarming rate and neonatal outcomes in extremely low birth weight infants (ELBWIs) with hypothermia.
All ELBWIs with hypothermia (temperature <36.0°C) on neonatal intensive care unit (NICU) admission were retrospectively evaluated. Rewarming rate was analyzed as both a dichotomous (≥0.5°C/h rapid group; <0.5°C/h slow group) and a continuous variable. Multivariable analysis was performed to explore the relation between rewarming rate and several outcomes, adjusting for clinically relevant confounders.
Hypothermia on NICU admission was present in 182 out of 744 ELBWIs (24.5%). The rewarming rate was slow in 109 subjects (59.9%) and rapid in 73 subjects (40.1%), with a median rewarming rate of 0.29°C/h (IQR 0.2-0.35) and 0.76°C/h (IQR 0.61-1.09), respectively (P < .0001). The median rewarming time was 340 minutes (IQR 250-480) and 170 minutes (IQR 110-230), respectively (P < .0001). After adjusting for clinically relevant confounders, we did not find significant associations between rewarming rate group (≥0.5°C/h vs <0.5°C/h) and neonatal outcomes. When we considered the rewarming rate as continuous variable, a higher rewarming rate was identified as a protective factor for respiratory distress syndrome (OR 0.39, 95% CI 0.17-0.87; P = .02).
In ELBWIs with hypothermia upon NICU admission, there were no significant differences between rapid or slow rewarming rate and major neonatal outcomes. A higher rewarming rate was associated with a reduced incidence of respiratory distress syndrome.
Neonatal thermoregulation
2006, Journal of Neonatal Nursing
Citation Excerpt :
if nothing is available or if the baby is clinically stable, skin-to-skin contact with the mother can be used in a warm room (at least 25.0 °C) (WHO, 1997). In cases of severe hypothermia (body temperature below 32.0 °C), studies suggest that fast rewarming over a few hours is preferable to slow rewarming over several days (Kaplan and Eidelman, 1984). If none of the above mentioned equipment is available, skin-to-skin contact or a warm room or cot can be used.
Thermoregulation is the ability to balance between heat production and heat loss in order to maintain body temperature within a certain normal range. The provision of a thermoneutral environment is an essential component of the immediate and longer term care of newborn infants. Cold stress and hyperthermia may have serious metabolic consequences for all newborns. In the preterm these consequences may be devastating and may increase both morbidity and mortality rates. Health professionals have a responsibility to be aware of and to ensure that the thermoregulatory needs of the infant are upheld in order to provide them with the best start possible. Current medical literature lacks well designed, prospective, randomized controlled trials for both diagnosis and intervention of providing thermoneutral environment and systematic reviews report that none of the interventions have serious adverse effects.
Hot topics in cold medicine: Controversies in accidental hypothermia
2001, Clinical Pediatric Emergency Medicine
Hypothermia confronts clinicians with an array of unfamiliar challenges and decisions. Confusion has been increased by conflicting recommendations in several areas of controversy. After a focused review, this report seeks to summarize current understanding of rewarming and other therapies in hypothermia, concentrating on areas of apparent controversy. Recommendations are made regarding appropriate rewarming strategies, considering both theoretical and actual effectiveness. Logistic problems that hobble rewarming efforts are discussed, and practical solutions are suggested. The risks and benefits of treatments, including external rewarming, cardiac compressions, orotracheal intubation, and administration of room-temperature intravenous fluid, are considered. Finally, the adage, “No one is dead until they're warm and dead.” is revisited.
Successful Resuscitation of a Severely Hypothermic Neonate
1994, Annals of Emergency Medicine
A profoundly hypothermic 5-hour-old infant in cardiac arrest was brought to the emergency department by paramedics. The infant was found wrapped in a garbage bag inside a freezer. She had been in the freezer for approximately four hours. Her initial rectal temperature was 16.2°C. Active external and core warming modalities, including warm blanket, radiant heat lamp, warm humidified air, heated gastric lavage, and heated bladder lavage, were used to rewarm the infant. Her temperature rose to 30.5°C in three hours (4.8°C/hr). The infant converted from a slow idioventricular rhythm to sinus bradycardia at 49 minutes (20.4°C) into the resuscitation. At 53 minutes (21.5°C), the infant moved both upper extremities. At the time of discharge from the hospital, she had no significant physical or neurologic problems. Neurologic examination at 4 months was normal. This report supports prior recommendations to aggressively rewarm severely hypothermic infants in cardiac arrest.
[Thompson DA, Anderson N: Successful resuscitation of a severely hypothermic neonate. Ann Emerg Med June 1994;23:1390-1393.]
Accidental hypothermia
1992, The Journal of Pediatrics

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^*: Supported in part by a grant from the Pinhas Sapir Fund of Mifal Hapayis.

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Improved prognosis in severely hypothermic newborn infants treated by rapid rewarming*

Cold injury due to accidental exposure to cold

Lancet

Cold injury of the newborn

N Engl J Med

Cold injury in the newborn

Br Med J

Severe hypothermia in Glasgow infants in winter

Lancet

Kalteschaden im Subtropischen Klima

Ann Pediatr

Cold injury in early infancy

Israel J Med Sci

Infection in neonatal hypothermia

Arch Dis Child

Hypothermia. Pathophysiology, clinical settings and management

Ann Intern Med

Editorial: Treating accidental hypothermia

Br Med J

Treatment of profound hypothermia

JAMA