[Corrected QT interval during therapeutic hypothermia in hypoxic ischaemic encephalopathy]

QTc Intervals Are Prolonged in Late Preterm and Term Neonates during Therapeutic Hypothermia but Normalize Afterwards

Background: There are anecdotal reports on reversible QTc prolongation during therapeutic hypothermia (TH) for moderate to severe neonatal encephalopathy after asphyxia. As the QTc interval is a relevant biomarker for pharmacovigilance during medication development, a structured search and review on published neonatal QTc values to generate reference values is warranted to facilate medication development in this specific population. Methods: A structured search and literature assessment (PubMed, Embase, and Google Scholar) with ‘Newborn/Infant, QT and hypothermia’ was conducted (October 2021). Retrieved individual values were converted to QTc (Bazett) over postnatal age (day 1–7). Results: We retrieved 94 QTc intervals (during TH (n = 50, until day 3) or subsequent normothermia (n = 44, day 4–7)) in 33 neonates from 6 publications. The median (range) of QTc intervals during TH was 508 (430–678), and 410 (317–540) ms afterwards (difference 98 ms, or +28 ms/°C decrease). Four additional cohorts (without individual QTc intervals) confirmed the pattern and magnitude of the effect of body temperature on the QTc interval. Conclusions: We highlighted a relevant non-maturational covariate (°C dependent TH) and generated reference values for the QTc interval in this specific neonatal subpopulation. This knowledge on QTc during TH should be considered and integrated in neonatal medication development.

Successful Postnatal Cardiopulmonary Resuscitation Due to Defibrillation

An asphyxiated term neonate required postnatal resuscitation. After six minutes of cardio-pulmonary resuscitation (CPR) and two doses of epinephrine, spontaneous circulation returned, but was shortly followed by ventricular fibrillation. CPR and administration of magnesium, calcium gluconate, and sodium bicarbonate did not improve the neonate’s condition. A counter shock of five Joule was delivered and the cardiac rhythm immediately converted to sinus rhythm. The neonate was transferred to the neonatal intensive care unit and received post-resuscitation care. Due to prolonged QTc and subsequently suspected long-QT syndrome propranolol treatment was initiated. The neonate was discharged home on day 14 without neurological sequelae.

The Diagnostic Value of Cystatin C and Mild Hypothermia Therapy Based on Immunoturbidimetry Enhanced by Nanospheres in Asphyxia Neonate

In order to evaluate the early diagnosis value of CysC and the influence of mild hypothermia on the renal damage of asphyxia neonates, the serum cystatin C (CysC) levels of asphyxia neonates and normal neonates were measured by the nanomicrosphere-enhanced immunoturbidimetric method. The treatment was carried out, and the influence of mild hypothermia treatment on the renal damage of asphyxia neonates was analyzed. The results showed that the indicators of the asphyxia group were significantly higher than those of the control group, and the severe asphyxia group was significantly higher than that of the mild asphyxia group, which was statistically significant $\left(p<0.05\right)$ ; the heart rate of patients in the mild hypothermia treatment group decreased gradually with the decrease in body temperature. And compared with the control group, there was a significant difference ( $p<0.05$ ); after symptomatic treatment, the two groups of ALT, AST, BUN, and SCR were improved to varying degrees, and the difference was statistically significant compared with before treatment ( $p<0.05$ ). Studies have shown that serum CysC level can be used as an indicator to detect glomerular filtration function and early asphyxia newborns, and it is sensitive and specific for early diagnosis of kidney damage. At the same time, it can be used to monitor clinical renal function and determine the status of asphyxia newborns.

Management of Multi Organ Dysfunction in Neonatal Encephalopathy

Neonatal Encephalopathy (NE) describes neonates with disturbed neurological function in the first post-natal days of life. NE is an overall term that does not specify the etiology of the encephalopathy although it often involves hypoxia-ischaemia. In NE, although neurological dysfunction is part of the injury and is most predictive of long-term outcome, these infants may also have multiorgan injury and compromise, which further contribute to neurological impairment and long-term morbidities. Therapeutic hypothermia (TH) is the standard of care for moderate to severe NE. Infants with NE may have co-existing immune, respiratory, endocrine, renal, hepatic, and cardiac dysfunction that require individualized management and can be impacted by TH. Non-neurological organ dysfunction not only has a negative effect on long term outcome but may also influence the efficacy of treatments in the acute phase. Post resuscitative care involves stabilization and decisions regarding TH and management of multi-organ dysfunction. This management includes detailed neurological assessment, cardio-respiratory stabilization, glycaemic and fluid control, sepsis evaluation and antibiotics, seizure identification, and monitoring and responding to biochemical and coagulation derangements. The emergence of new biomarkers of specific organ injury may have predictive value and improve the definition of organ injury and prognosis. Further evidence-based research is needed to optimize management of NE, prevent further organ dysfunction and reduce neurodevelopmental impairment.