RESUMO
Importance: The association between place of birth and hypothermic neuroprotection after hypoxic-ischemic encephalopathy (HIE) in low- and middle-income countries (LMICs) is unknown. Objective: To ascertain the association between place of birth and the efficacy of whole-body hypothermia for protection against brain injury measured by magnetic resonance (MR) biomarkers among neonates born at a tertiary care center (inborn) or other facilities (outborn). Design, Setting, and Participants: This nested cohort study within a randomized clinical trial involved neonates at 7 tertiary neonatal intensive care units in India, Sri Lanka, and Bangladesh between August 15, 2015, and February 15, 2019. A total of 408 neonates born at or after 36 weeks' gestation with moderate or severe HIE were randomized to receive whole-body hypothermia (reduction of rectal temperatures to between 33.0 °C and 34.0 °C; hypothermia group) for 72 hours or no whole-body hypothermia (rectal temperatures maintained between 36.0 °C and 37.0 °C; control group) within 6 hours of birth, with follow-up until September 27, 2020. Exposure: 3T MR imaging, MR spectroscopy, and diffusion tensor imaging. Main Outcomes and Measures: Thalamic N-acetyl aspartate (NAA) mmol/kg wet weight, thalamic lactate to NAA peak area ratios, brain injury scores, and white matter fractional anisotropy at 1 to 2 weeks and death or moderate or severe disability at 18 to 22 months. Results: Among 408 neonates, the mean (SD) gestational age was 38.7 (1.3) weeks; 267 (65.4%) were male. A total of 123 neonates were inborn and 285 were outborn. Inborn neonates were smaller (mean [SD], 2.8 [0.5] kg vs 2.9 [0.4] kg; P = .02), more likely to have instrumental or cesarean deliveries (43.1% vs 24.7%; P = .01), and more likely to be intubated at birth (78.9% vs 29.1%; P = .001) than outborn neonates, although the rate of severe HIE was not different (23.6% vs 17.9%; P = .22). Magnetic resonance data from 267 neonates (80 inborn and 187 outborn) were analyzed. In the hypothermia vs control groups, the mean (SD) thalamic NAA levels were 8.04 (1.98) vs 8.31 (1.13) among inborn neonates (odds ratio [OR], -0.28; 95% CI, -1.62 to 1.07; P = .68) and 8.03 (1.89) vs 7.99 (1.72) among outborn neonates (OR, 0.05; 95% CI, -0.62 to 0.71; P = .89); the median (IQR) thalamic lactate to NAA peak area ratios were 0.13 (0.10-0.20) vs 0.12 (0.09-0.18) among inborn neonates (OR, 1.02; 95% CI, 0.96-1.08; P = .59) and 0.14 (0.11-0.20) vs 0.14 (0.10-0.17) among outborn neonates (OR, 1.03; 95% CI, 0.98-1.09; P = .18). There was no difference in brain injury scores or white matter fractional anisotropy between the hypothermia and control groups among inborn or outborn neonates. Whole-body hypothermia was not associated with reductions in death or disability, either among 123 inborn neonates (hypothermia vs control group: 34 neonates [58.6%] vs 34 [56.7%]; risk ratio, 1.03; 95% CI, 0.76-1.41), or 285 outborn neonates (hypothermia vs control group: 64 neonates [46.7%] vs 60 [43.2%]; risk ratio, 1.08; 95% CI, 0.83-1.41). Conclusions and Relevance: In this nested cohort study, whole-body hypothermia was not associated with reductions in brain injury after HIE among neonates in South Asia, irrespective of place of birth. These findings do not support the use of whole-body hypothermia for HIE among neonates in LMICs. Trial Registration: ClinicalTrials.gov Identifier: NCT02387385.
Assuntos
Lesões Encefálicas , Hipotermia Induzida , Hipóxia-Isquemia Encefálica , Recém-Nascido , Gravidez , Feminino , Humanos , Masculino , Lactente , Estudos de Coortes , Imagem de Tensor de Difusão , Centros de Atenção Terciária , Hipóxia-Isquemia Encefálica/diagnóstico por imagem , Hipóxia-Isquemia Encefálica/terapia , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Lesões Encefálicas/complicações , BiomarcadoresRESUMO
Although therapeutic hypothermia (TH) is the standard of care for hypoxic ischaemic encephalopathy in high-income countries, the safety and efficacy of this therapy in low-income and middle-income countries (LMICs) is unknown. We aimed to describe the feasibility of TH using a low-cost servo-controlled cooling device and the short-term outcomes of the cooled babies in LMIC. DESIGN: We recruited babies with moderate or severe hypoxic ischaemic encephalopathy (aged <6 hours) admitted to public sector tertiary neonatal units in India over a 28-month period. We administered whole-body cooling (set core temperature 33.5°C) using a servo-controlled device for 72 hours, followed by passive rewarming. We collected the data on short-term neonatal outcomes prior to hospital discharge. RESULTS: Eighty-two babies were included-61 (74%) had moderate and 21 (26%) had severe encephalopathy. Mean (SD) hypothermia cooling induction time was 1.7 hour (1.5) and the effective cooling time 95% (0.08). The mean (SD) hypothermia induction time was 1.7 hour (1.5 hour), core temperature during cooling was 33.4°C (0.2), rewarming rate was 0.34°C (0.16°C) per hour and the effective cooling time was 95% (8%). Twenty-five (51%) babies had gastric bleeds, 6 (12%) had pulmonary bleeds and 21 (27%) had meconium on delivery. Fifteen (18%) babies died before discharge from hospital. Heart rate more than 120 bpm during cooling (P=0.01) and gastric bleeds (P<0.001) were associated with neonatal mortality. CONCLUSIONS: The low-cost servo-controlled cooling device maintained the core temperature well within the target range. Adequately powered clinical trials are required to establish the safety and efficacy of TH in LMICs. CLINICAL TRIAL REGISTRATION NUMBER: NCT01760629.
RESUMO
BACKGROUND: Therapeutic hypothermia reduces death and disability after moderate or severe neonatal encephalopathy in high-income countries and is used as standard therapy in these settings. However, the safety and efficacy of cooling therapy in low- and middle-income countries (LMICs), where 99% of the disease burden occurs, remains unclear. We will examine whether whole body cooling reduces death or neurodisability at 18-22 months after neonatal encephalopathy, in LMICs. METHODS: We will randomly allocate 408 term or near-term babies (aged ≤ 6 h) with moderate or severe neonatal encephalopathy admitted to public sector neonatal units in LMIC countries (India, Bangladesh or Sri Lanka), to either usual care alone or whole-body cooling with usual care. Babies allocated to the cooling arm will have core body temperature maintained at 33.5 °C using a servo-controlled cooling device for 72 h, followed by re-warming at 0.5 °C per hour. All babies will have detailed infection screening at the time of recruitment and 3 Telsa cerebral magnetic resonance imaging and spectroscopy at 1-2 weeks after birth. Our primary endpoint is death or moderate or severe disability at the age of 18 months. DISCUSSION: Upon completion, HELIX will be the largest cooling trial in neonatal encephalopathy and will provide a definitive answer regarding the safety and efficacy of cooling therapy for neonatal encephalopathy in LMICs. The trial will also provide important data about the influence of co-existent perinatal infection on the efficacy of hypothermic neuroprotection. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02387385 . Registered on 27 February 2015.