TOBY (TOtal Body hYpothermia): a Study of Treatment for Perinatal Asphyxia

This is a multicentre prospective randomised controlled trial to determine whether a reduction of body temperature by 3-4°C following perinatal asphyxia improves survival without neurodevelopmental disability.

Full term infants will be randomised within 6 hours of birth to either a control group with the rectal temperature kept at 37 ± 0.2°C or to whole body cooling with the rectal temperature kept at 33.5 ± 0.5°C for 72 hours followed by slow rewarming.

The outcome will be assessed at 18 months of age by survival and neurological and neurodevelopmental testing.

Eligibility criteria:

Term infants less than 6 hours after birth with moderate or severe perinatal asphyxia (a combination of clinical and EEG criteria).

Exclusion criteria

Infants expected to be 6 hours of age at the time of randomisation or infants with major congenital abnormalities.

Intervention:

Intensive care with whole body cooling versus intensive care without whole body cooling (babies are cooled to 33.5°C for 72 hours)

Main Outcomes:

Death and severe neurodevelopmental impairment at 18 months of age

Secondary Outcomes:

Cerebral thrombosis or haemorrhage, persistent hypotension, pulmonary hypertension, abnormal coagulation, arrhythmia and sepsis in the neonatal period. Neurological impairments at 18 months

Number of patients required: 236.

On 30th November 2006, when recruitment closed, 325 babies had been recruited.

Inclusion criteria

The infant will be assessed sequentially by criteria A, B and C listed below:

A. Infants =>36 completed weeks gestation admitted to the Neonatal Intensive Care Unit (NICU) with at least one of the following:

• Apgar score of =<5 at 10 minutes after birth
• Continued need for resuscitation, including endotracheal or mask ventilation, at 10 minutes after birth
• Acidosis within 60 minutes of birth (defined as any occurrence of umbilical cord, arterial or capillary pH <7.00)
• Base Deficit =>16 mmol/L in umbilical cord or any blood sample (arterial, venous or capillary) within 60 minutes of birth

Infants that meet criteria A will be assessed for whether they meet the neurological abnormality entry criteria (B) by trained personnel:

B. Moderate to severe encephalopathy, consisting of altered state of consciousness (lethargy, stupor or coma) AND at least one of the following:

• hypotonia
• abnormal reflexes including oculomotor or pupillary abnormalities
• absent or weak suck
• clinical seizures

Infants that meet criteria A & B will be assessed by amplitude-integrated electroencephalogram (aEEG) (read by trained personnel):

C. At least 30 minutes duration of amplitude integrated EEG recording that shows abnormal background aEEG activity or seizures. There must be one of the following:

• normal background with some seizure activity
• moderately abnormal activity
• suppressed activity
• continuous seizure activity

Exclusion criteria

• Infants expected to be > 6 hours of age at the time of randomisation
• Major congenital abnormalities, such as diaphragmatic hernia requiring ventilation, or congenital abnormalities suggestive of chromosomal anomaly or other syndromes that include brain dysgenesis