Cool heads: ethical issues associated with therapeutic hypothermia for newborns

Comparison of selective head cooling versus whole-body cooling

BACKGROUND

This study compared selective head cooling (SHC) and whole-body cooling (WBC) in newborns with hypoxic-ischemic encephalopathy (HIE).

METHODS

We conducted a prospective randomized small-scale pilot study in newborns with HIE, born after >35 weeks of gestation. The patients were randomly assigned to receive SHC or WBC.

RESULTS

The SHC group consisted of 17 patients, and the WBC group, 12 patients. There was no significant difference in adverse effects related to cooling therapy between the two groups. During the 12 month study period, seven patients in the SHC group and four in the WBC group died, but the difference was not significant (P = 0.667). Among the patients alive at 12 months after treatment, six in the SHC group and four in the WBC group had severe disabilities; the difference was not significant (P = 0.671). When the composite outcome of death or severe disability was evaluated, the difference between the SHC group (77%, n = 13) and the WBC group (67%, n = 8) was not significant (P = 0.562). Moreover, the number of survivors without disability at 12 months after treatment did not differ significantly between the SHC group (n = 3) and the WBC group (n = 4; P = 0.614).

CONCLUSIONS

There were no significant differences in adverse effects, 12 month neuromotor development, or mortality rate between SHC and WBC in newborns with HIE, born after >35 weeks of gestation.

Comparison of selective head cooling therapy and whole body cooling therapy in newborns with hypoxic ischemic encephalopathy: short term results

AIM

In this study, it was aimed to investigate which method was superior by applying selective head cooling or whole body cooling therapy in newborns diagnosed with moderate or severe hypoxic ischemic encephalopathy.

MATERIALS AND METHOD

Newborns above the 35th gestational age diagnosed with moderate or severe hypoxic ischemic encephalopathy were included in the study and selective head cooling or whole body cooling therapy was performed randomly. The newborns who were treated by both methods were compared in terms of adverse effects in the early stage and in terms of short-term results. Ethics committee approval was obtained for the study (06.01.2010/35).

RESULTS

Fifty three babies diagnosed with hypoxic ischemic encephalopathy were studied. Selective head cooling was applied to 17 babies and whole body cooling was applied to 12 babies. There was no significant difference in terms of adverse effects related to cooling therapy between the two groups. When the short-term results were examined, it was found that the hospitalization time was 34 (7-65) days in the selective head cooling group and 18 (7-57) days in the whole body cooling group and there was no significant difference between the two groups (p=0.097). Four patients in the selective head cooling group and two patients in the whole body cooling group were discharged with tracheostomy because of the need for prolonged mechanical ventilation and there was no difference between the groups in terms of discharge with tracheostomy (p=0.528). Five patients in the selective head cooling group and three patients in the whole body cooling group were discharged with a gastrostomy tube because they could not be fed orally and there was no difference between the groups in terms of discharge with a gastrostomy tube (p=0.586). One patient who was applied selective head cooling and one patient who was applied whole body cooling died during hospitalization and there was no difference between the groups in terms of mortality (p=0.665).

CONCLUSIONS

There is no difference between the methods of selective head cooling and whole body cooling in terms of adverse effects and short-term results.

The outcome of treatment limitation discussions in newborns with brain injury

BACKGROUND

Most deaths in severely brain-injured newborns in neonatal intensive care units (NICUs) follow discussions and explicit decisions to limit life-sustaining treatment. There is little published information on such discussions.

OBJECTIVE

To describe the prevalence, nature and outcome of treatment limitation discussions (TLDs) in critically ill newborns with severe brain injury.

DESIGN

A retrospective statewide cohort study.

SETTING

Two tertiary NICUs in South Australia.

PATIENTS

Ventilated newborns with severe hypoxic ischaemic encephalopathy and periventricular/intraventricular haemorrhage (P/IVH) admitted over a 6-year period from 2001 to 2006.

MAIN OUTCOME MEASURES

Short-term outcome (until hospital discharge) including presence and content of TLDs, early childhood mortality, school-age functional outcome.

RESULTS

We identified 145 infants with severe brain injury; 78/145 (54%) infants had documented TLDs. Discussions were more common in infants with severe P/IVH or hypoxic-ischaemic encephalopathy (p<0.01). Fifty-six infants (39%) died prior to discharge, all following treatment limitation. The majority of deaths (41/56; 73%) occurred in physiologically stable infants. Of 78 infants with at least one documented TLD, 22 (28%) survived to discharge, most in the setting of explicit or inferred decisions to continue treatment. Half of long-term survivors after TLD (8/16, 50%) were severely impaired at follow-up. However, two-thirds of surviving infants with TLD in the setting of unilateral P/IVH had mild or no disability.

CONCLUSIONS

Some critically ill newborn infants with brain injury survive following TLDs between their parents and physicians. Outcome in this group of infants provides valuable information about the integrity of prognostication in NICU, and should be incorporated into counselling.

Neuroprotective effect of levetiracetam on hypoxic ischemic brain injury in neonatal rats

PURPOSE

Hypoxic-ischemic brain injury that occurs in the perinatal period is one of the leading causes of mental retardation, visual and auditory impairment, motor defects, epilepsy, cerebral palsy, and death in neonates. The severity of apoptosis that develops after ischemic hypoxia and reperfusion is an indication of brain injury. Thus, it may be possible to prevent or reduce injury with treatments that can be given before the reperfusion period following hypoxia and ischemia. Levetiracetam is a new-generation antiepileptic drug that has begun to be used in the treatment of epilepsy.

METHODS

The present study investigated the effects of levetiracetam on neuronal apoptosis with histopathological and biochemical tests in the early period and behavioral experiments in the late period.

RESULTS

This study showed histopathologically that levetiracetam reduces the number of apoptotic neurons and has a neuroprotective effect in a neonatal rat model of hypoxic-ischemic brain injury in the early period. On the other hand, we demonstrated that levetiracetam dose dependently improves behavioral performance in the late period.

CONCLUSIONS

Based on these results, we believe that one mechanism of levetiracetam's neuroprotective effects is due to increases in glutathione peroxidase and superoxide dismutase enzyme levels. To the best of our knowledge, this study is the first to show the neuroprotective effects of levetiracetam in a neonatal rat model of hypoxic-ischemic brain injury using histopathological, biochemical, and late-period behavioral experiments within the same experimental group.

Therapeutic cooling for perinatal asphyxia-Indian experience

Therapeutic hypothermia (TH) has been established as standard of care for term babies with perinatal asphyxia in developed countries. However, it is yet to gain momentum in India. This review summarizes some of the TH trials conducted in India and the various related issues in adapting the same for the Indian context.

Hypothermia for neonatal hypoxic-ischemic encephalopathy: may an early amplitude-integrated EEG improve the selection of candidates for cooling?

OBJECTIVE

To report our experience in the selection of newborns candidate to therapeutic hypothermia.

METHODS

Retrospective study involving 47 newborns suffering from perinatal asphyxia from January 2008 to September 2011.

RESULTS

Thirty-five of 47 newborns admitted to our hospital fulfilled metabolic and neurological criteria for recruitment and were cooled. aEEG was carried out in 26 of them and resulted always abnormal. In three of the 12 newborns with only metabolic criteria, aEEG was moderately abnormal. They were cooled and their outcome (evaluated by General Movements and Griffiths Mental Development Scales for children aged 0-2 years) is good. Three additional newborns who only met the metabolic criterion reached our hospital after the therapeutic window for hypothermia and exhibited seizures; their outcome is poor.

CONCLUSIONS

In our experience, the inclusion of aEEG in the entry criteria would not have precluded newborns with neurological criteria from cooling. On the contrary, without an early aEEG, we would have excluded from hypothermia infants with moderate hypoxic-ischemic encephalopathy without precocious neurological signs who exhibited only the metabolic criterion, but with abnormal aEEG. If further studies will confirm that early aEEG might identify newborns suitable for cooling even in the absence of clinical signs, a revision of the entry criteria should be considered.

Hypothermia for the treatment of infants with hypoxic-ischemic encephalopathy

Neonatal encephalopathy affects 2 to 5 of every 1000 live births and represents a major cause of mortality and long-term morbidity in affected infants. Hypoxic ischemic encephalopathy (HIE) is the major cause of encephalopathy in the neonatal period. Until recently, management of a newborn with encephalopathy has consisted largely of supportive care to restore and maintain cerebral perfusion, provide adequate gas exchange and treat seizure activity. Recent randomized controlled trials have shown that mild therapeutic hypothermia (cooling) initiated within 6 h of birth reduces death and disability in these infants. Cooling can be accomplished through whole-body cooling or selective head cooling. Meta-analysis of these trials suggests that for every six or seven infants with moderate to severe HIE who are treated with mild hypothermia, there will be one fewer infant who dies or has significant neurodevelopmental disability. In response to this evidence, major policy makers and guideline developers have recommended that cooling therapy be offered to infants with moderate to severe HIE. The dissemination of this new therapy will require improved identification of infants with HIE and regional commitment to allow these infants to be cared for in a timely manner.

Ethics and hypothermia treatment

Hypothermia is the first effective neuroprotective intervention for newborns who are critically ill following a life-threatening asphyxial insult. It is not surprising that it has raised complex and controversial ethical dilemmas for investigators and clinicians. Given the history of iatrogenic disasters in neonatology, there has been an understandable reluctance to incorporate hypothermia into routine clinical practice until there is persuasive evidence from high quality randomised trials. This article reviews ethical issues that arose during the design of the original clinical trials, the implications of accumulating evidence of safety and efficacy, and the problems of ensuring informed parental participation in treatment decisions.

MRI and withdrawal of life support from newborn infants with hypoxic-ischemic encephalopathy

The majority of deaths in infants with hypoxic-ischemic encephalopathy (HIE) follow decisions to withdraw life-sustaining treatment. Clinicians use prognostic tests including MRI to help determine prognosis and decide whether to consider treatment withdrawal. A recently published meta-analysis provided valuable information on the prognostic utility of magnetic resonance (MR) biomarkers in HIE and suggested, in particular, that proton MR spectroscopy is the most accurate predictor of neurodevelopmental outcome. How should this evidence influence treatment-limitation decisions? In this article I outline serious limitations in existing prognostic studies of HIE, including small sample size, selection bias, vague and overly inclusive outcome assessment, and potential self-fulfilling prophecies. Such limitations make it difficult to answer the most important prognostic question. Reanalysis of published data reveals that severe abnormalities on conventional MRI in the first week have a sensitivity of 71% (95% confidence interval: 59%-91%) and specificity of 84% (95% confidence interval: 68%-93%) for very adverse outcome in infants with moderate encephalopathy. On current evidence, MR biomarkers alone are not sufficiently accurate to direct treatment-limitation decisions. Although there may be a role for using MRI or MR spectroscopy in combination with other prognostic markers to identify infants with very adverse outcome, it is not possible from meta-analysis to define this group clearly. There is an urgent need for improved prognostic research into HIE.

Hypothermia for hypoxic-ischemic brain injury

Hypoxic-ischemic brain injury and hypoxic-ischemic encephalopathy (HIE) remain a serious problem for both preterm and term neonates with the spectrum of injury ranging from neuronal injury to encephalopathy and death. Neonatal encephalopathy due to such injury occurs in 3-9 of every 1000 term infants. Of these, it is estimated that nearly a third to a half will either have severe adverse outcomes or die. Treatment of infants with HIE remains generally supportive with attention to resuscitation, fluid and electrolyte homeostasis, maintenance of acid-base balance, nutrition and feeding issues and treatment of seizures.