Subcutaneous fat necrosis and hypercalcemia following therapeutic hypothermia--a patient report and review of the literature

Cooling Under a Blanketrol System Versus Cooling With an Arctic Sun Thermoregulation System (CATS) for Neonates Undergoing Therapeutic Hypothermia

Background Despite evidence suggesting improved outcomes in neonates with hypoxic-ischemic encephalopathy (HIE) treated with therapeutic hypothermia (TH), data on the impact of temperature variability during cooling and its association with clinical outcomes remain limited. Objective To compare the efficacy and ease of use of two different cooling systems, the Arctic Sun (Medivance, Inc., Louisville, CO) vs. the Blanketrol III (Gentherm Medical, Cincinnati, OH) on achieving TH, temperature variability, and clinical outcomes in neonates with HIE undergoing TH. Methods This study was conducted at the Baylor Scott and White Medical Center's Level IV NICU. The study employed a retrospective cohort design, comparing infants treated with the Arctic Sun device (from December 2020 to August 2021) to a historical cohort treated with the Blanketrol system (from January 2017 to November 2020). Both groups were evaluated for clinical characteristics, patients' outcomes, and ease of use of the cooling devices. Ease of use was assessed through a self-developed survey administered to NICU nurses. Core body temperatures throughout the cooling course were documented at four-hour intervals, including induction, maintenance, and rewarming phases. Results Twenty-two infants were cooled using the Arctic Sun system, and 44 infants were cooled with the Blanketrol device. Median birth weight and gestational age were comparable. There were no significant differences in one-minute and five-minute appearance, pulse, grimace, activity, and respiration (APGAR) scores. The Arctic Sun group had a significantly higher rate of maternal morbidities, including diabetes and placental abruption. Although the median temperature achieved with both devices was 33.5°C, temperature variability was significantly greater with the Blanketrol device (p = 0.03). Thrombocytopenia rates were statistically different between the groups (9% in Arctic Sun vs. 38% in Blanketrol, p = 0.001). Although the Blanketrol group had higher rates of disseminated intravascular coagulation (48% vs. 37%), hypercalcemia (23% vs. 5%), and subcutaneous fat necrosis (7% vs. 5%), these differences were not statistically significant. A nurses' survey on ease of use revealed a strong preference for the Arctic Sun cooling system. Over 85% of nurses found it easier to learn and set up and required less manual intervention than the Blanketrol device. Conclusions Gel adhesive pad-based TH is a potentially superior modality to traditional water-circulating cooling devices. These pads offer advantages in user-friendliness, improved temperature control precision, and potentially reduced adverse event profiles.

Pamidronate as first-line treatment of hypercalcemia in neonatal subcutaneous fat necrosis: A case series

Background

Subcutaneous fat necrosis (SCFN) can be complicated by severe hypercalcemia, which is frequently asymptomatic. Nephrocalcinosis is associated with hypercalcemia and, in other clinical settings, has been linked to furosemide and glucocorticoid use. First-line bisphosphonate therapy treating hypercalcemia in neonatal SCFN is not well described.

Objectives

To describe the biochemical changes and risk of nephrocalcinosis in infants with hypercalcemia, secondary to neonatal SCFN, treated with initial pamidronate.

Methods

A retrospective chart review of five infants treated with initial pamidronate and without furosemide or glucocorticoids. Data were collected on the following: timing of presentation, therapeutic response, and presence of nephrocalcinosis.

Results

Hypercalcemia resolved after 2.8±1.7 days; this is compared to 7.6±2.8 days from previously reported cases utilising alternative therapies (P=0.012). There were no episodes of rebound hypercalcemia or hypocalcemia. Nephrocalcinosis was present in four of five cases. When including published cases, age at diagnosis was associated with presenting serum calcium (P=0.003) and nephrocalcinosis was associated with higher serum calcium (P=0.014) and time from SCFN to hypercalcemia diagnosis (P=0.002).

Conclusions

This retrospective case series demonstrates that first-line pamidronate treatment was effective and safe in the resolution of hypercalcemia. Nephrocalcinosis was observed, despite the avoidance of furosemide and glucocorticoid therapy, and associated with greater disease severity and duration of hypercalcemia.

Occult Massive Visceral Fat Necrosis Following Therapeutic Hypothermia for Neonatal Encephalopathy

Therapeutic hypothermia (head or whole-body cooling) improves survival and neurodevelopmental outcome in term newborns with moderate-to-severe encephalopathy. Hypothermia treatment is well tolerated; the most common side effect is thrombocytopenia. In about 1% of infants, focal subcutaneous fat necrosis has been reported. We describe a case of clinically unsuspected massive visceral fat necrosis in a term infant with Apgar score 0 at 1 min ("resuscitated apparently stillborn" infant) who was treated with therapeutic hypothermia for 72 h and expired on the 25th day of life following a neonatal course complicated by severe encephalopathy, pulmonary artery hypertension, persistent thrombocytopenia, hypoglycemia, and severe basal ganglia-thalamic abnormalities on magnetic resonance imaging. Postmortem examination revealed extensive visceral (brown) fat necrosis, involving thoracic, abdominal, and retroperitoneal adipose tissue, with distinctive sparing of the subcutaneous (white) fat. The fulminant-yet clinically occult-visceral fat necrosis seen in this case suggests that (lesser degrees of) fat necrosis may go unrecognized in hypoxic-ischemic newborns, especially in those treated with hypothermia, and underscores the importance of close monitoring of encephalopathic newborns both in the short and long terms for complications of fat necrosis (hypercalcemia and nephrocalcinosis).

Macrosomia and haemodynamic instability may represent risk factors for subcutaneous fat necrosis in asphyxiated newborns treated with hypothermia

AIM

To identify additional risk factors other than asphyxia and hypothermia in newborns developing subcutaneous fat necrosis (SCFN).

METHODS

We conducted a prospective cohort study of all term asphyxiated newborns treated with hypothermia from 2008 to 2015. The presence and location of SCFN were recorded at the time of discharge or at follow-up visits. To identify the risk factors for developing SCFN, we compared the perinatal characteristics of those newborns who developed SCFN with those who did not.

RESULTS

The newborns developing SCFN had significantly higher birthweights compared with those newborns who did not develop SCFN. Among the newborns with a birthweight equal or superior to the 90th percentile, those who developed SCFN had a significantly higher use of inotropic support and higher maximum troponin levels during their initial hospitalisation.

CONCLUSION

A higher birthweight represented an independent risk factor for developing SCFN in asphyxiated newborns treated with hypothermia. When macrosomia is present, other risk factors related to haemodynamic instability during the initial hospitalisation may also increase the risk of developing SCFN.

Temperature control during therapeutic hypothermia for newborn encephalopathy using different Blanketrol devices

Therapeutic hypothermia improves the survival and neurodevelopmental outcome of infants with newborn encephalopathy of a hypoxic-ischemic origin. The NICHD Neonatal Research Network (NRN) Whole Body Cooling trial used the Cincinnati Sub-Zero Blanketrol II to achieve therapeutic hypothermia. The Blanketrol III is now available and provides additional cooling modes that may result in better temperature control. This report is a retrospective comparison of infants undergoing hypothermia using two different cooling modes of the Blanketrol device. Infants from the NRN trial were cooled with the Blanketrol II using the Automatic control mode (B2 cohort) and were compared with infants from two new NRN centers that adopted the NRN protocol and used the Blanketrol III in a gradient mode (B3 cohort). The primary outcome was the percent time the esophageal temperature stayed between 33°C and 34°C (target 33.5°C) during maintenance of hypothermia. Cohorts had similar birth weight, gestational age, and level of encephalopathy at the initiation of therapy. Baseline esophageal temperature differed between groups (36.6°C ± 1.0°C for B2 vs. 33.9°C ± 1.2°C for B3, p<0.0001) reflecting the practice of passive cooling during transport prior to initiation of active device cooling in the B3 cohort. This difference prevented comparison of temperatures during induction of hypothermia. During maintenance of hypothermia the mean and standard deviation of the percent time between 33°C and 34°C was similar for B2 compared to B3 cohorts (94.8% ± 0.1% vs. 95.8% ± 0.1%, respectively). Both the automatic and gradient control modes of the Blanketrol devices appear comparable in maintaining esophageal temperature within the target range during maintenance of therapeutic hypothermia.

Subcutaneous fat necrosis in neonates with hypoxic ischaemic encephalopathy registered in the Swiss National Asphyxia and Cooling Register

Background

Neonates with hypoxic ischaemic encephalopathy (HIE) are routinely treated with therapeutic hypothermia (TH) for 72 h in order to improve neurological outcome. Subcutaneous fat necrosis (SCFN) is an adverse event occurring in neonates with HIE.

Methods

We analyzed risk factors for SCFN regarding demographic factors, cooling methods and deviation from target temperature range during hypothermia therapy. Data of all neonates registered in the National Asphyxia and Cooling Register in Switzerland between 2011 and 2013 were analyzed.

Results

2.8 % of all cooled neonates with HIE developed SCFN. Perinatal and neonatal characteristics did not differ between neonates with and without SCFN. Applied cooling methods did not correlate with the occurrence of SCFN. In neonates with SCFN 83.3 % of all noted temperatures were within the target temperature range versus 77.5 % in neonates without SCFN. Neonates with SCFN showed 3.6 % of all measured temperatures below target temperature range compared to 12.7 % in neonates without SCFN.

Conclusion

Subcutaneous fat necrosis in the neonate with HIE undergoing TH is a potential adverse event that seems to occur independently from the whole-body cooling method applied and proportion of temperature measurements outside target temperature range. In this cohort, moderate overcooling associated with moderate hypothermia (33.0–34.0 °C) does not seem to be an independent risk factor for SCFN. There is no correlation between the severity of HIE and incidence of SCFN.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0395-7) contains supplementary material, which is available to authorized users.

Tender skin nodules in a newborn

Subcutaneous fat necrosis of infancy is a rare disorder of subcutaneous adipose tissue that is sometimes complicated by hypercalcemia. Complete resolution is common. From the pediatrician's point of view, the disease is a rare but important cause of inconsolable cry in a newborn.

Hypercalcemia due to subcutaneous fat necrosis in a newborn after total body cooling

Subcutaneous fat necrosis is an inflammatory disorder of adipose tissue. Although patients need long-term follow-up to prevent hypercalcemia, the prognosis is generally favorable. We herein present a case of a newborn who developed subcutaneous fat necrosis-related hypercalcemia after hypothermia treatment for hypoxic ischemic encephalopathy. Widespread use of hypothermia treatment for hypoxic ischemic encephalopathy in the neonatal intensive care unit may increase the risk of developing subcutaneous fat necrosis and subsequently hypercalcemia. Great care should be taken to recognize skin findings early in newborns receiving hypothermia treatment, and those diagnosed with subcutaneous fat necrosis require close follow-up because they are at risk for developing hypercalcemia.

Strategies for reducing the incidence of skin complications in newborns treated with whole-body hypothermia

OBJECTIVE

To present the results of a strategy designed to reduce the incidence of skin complications in newborns with hypoxic-ischemic encephalopathy treated with moderate whole-body hypothermia.

DESIGN

Retrospective study.

SETTING

Neonatal Intensive Care Unit (NICU).

PATIENTS

Thirty-nine neonates cooled in the considered period.

INTERVENTION

Starting from January 2008, for neonates treated with moderate whole-body hypothermia (33.5 °C), the cooling system was set in "automatic servo-controlled mode (ACM)", where the temperature of the circulating water could vary between 4 °C and 42 °C. Starting from January 2009, cooling blankets were used in another type of automatic mode, the "gradient variable mode (GVM)", where the circulating water was maintained at a specific pre-set gradient towards the patient's body temperature, and a specific nursing protocol (NP) was adopted.

MEASUREMENTS AND MAIN RESULTS

Two of the eleven newborns treated with the "ACM" exhibited skin complications compatible with subcutaneous fat necrosis (SFN). None of the twenty-eight newborns treated with the "GVM" exhibited skin complications. A comparison of the biochemical and hematological data between these two groups revealed that newborns treated after the adopting of a NP and the "GVM" showed lower serum protein C and calcium levels, and higher platelet levels.

CONCLUSIONS

Our data suggest that newborns undergoing therapeutic cooling may benefit from a specific NP and correct cooling unit setting. Should further studies confirm our data, this nursing approach could be easily adopted.

Follow-up during early infancy of newborns diagnosed with subcutaneous fat necrosis

Subcutaneous fat necrosis of the newborn (ScFN) is an uncommon condition caused by generalized and/or local tissue hypoperfusion. The skin lesions of ScFN tend to improve spontaneously. However, ScFN may also lead to complications which cause serious problems. The severity of the etiologic factors contributing to the development of the disease determines the severity of complications. Therefore, these patients should be closely monitored for complications, especially for hypercalcemia which may be life-threatening. The severity and duration of hypercalcemia are associated with the extensity of skin lesions. We present a newborn who developed ScFN as a result of systemic hypotension. The ScFN resolved after the first few weeks of life, but the patient developed mild hypercalcemia during the 4-month follow-up period. The infant was breast-fed during follow-up, and vitamin D prophylaxis was not initiated. The hypercalcemia resolved within four months without any complications. We would like to draw attention to the need to monitor serum calcium levels in these infants and to refrain from initiating vitamin D prophylaxis in the first months of life.