Cot-side electroencephalography for outcome prediction in preterm infants: observational study.

OBJECTIVE: To assess the use of two-channel electroencephalographical (EEG) recordings for predicting adverse neurodevelopmental outcome (death or Bayley II mental developmental index/psychomotor developmental index < 70) in extremely preterm infants and to determine the relationship between quantitative continuity measures and a specialist neurophysiologist assessment of the same EEG segment for predicting outcome. DESIGN: Observational study. SETTING: The study was conducted in a neonatal intensive care unit. PATIENTS: Preterm infants born <29 weeks' gestation. INTERVENTIONS: Two-channel EEGs using the reBRM2 monitor (BrainZ Instruments, Auckland, New Zealand) within 48 h of delivery. One-hour segments were analysed, blinded to the clinical outcome, by off-line quantitative analysis of continuity and a review of the raw EEG by a neurophysiologist. MAIN OUTCOME MEASURES: Developmental assessment at a median of 15 months' corrected age. RESULTS: 76 infants had an EEG within 48 h of delivery and a developmental assessment. The analysed segment of the EEG was obtained at 24 (3-48) h of age (median (range)). The neurophysiologist's assessment was a better predictor of adverse outcome than the continuity measures (positive predictive value 95% CI 75 (54% to 96%) vs 41 (22% to 60) at 25-µV threshold, negative predictive value 88 (80% to 96%) vs 84 (74% to 94%) and positive likelihood ratio 9.0 (3.2 to 24.6) vs 2.0 (1.2 to 3.6)). All the infants with definite seizures identified by the neurophysiologist had poor outcomes. CONCLUSIONS: Modified cot-side EEG has potential to assist with identification of extremely preterm infants at risk for adverse neurodevelopmental outcomes. However, analysis by a neurophysiologist performed better than the currently available continuity analyses.

Early low cardiac output is associated with compromised electroencephalographic activity in very preterm infants.

Low cerebral blood flow in preterm infants has been associated with discontinuous electroencephalography (EEG) activity that in turn has been associated with poor long-term prognosis. We examined the relationships between echocardiographic measurements of blood flow, blood pressure (BP), and quantitative EEG data as surrogate markers of cerebral perfusion and function with 112 sets of paired data obtained over the first 48 h after birth in 40 preterm infants (24-30 wk of gestation, 510-1900 g at delivery). Echocardiographic measurements of right ventricular output (RVO) and superior vena caval (SVC) flow were performed serially. BP recordings were obtained from invasive monitoring or oscillometry. Modified cotside EEGs were analyzed for quantitative amplitude and continuity measurements. RVO 12 h after birth was related to both EEG amplitude at 12 and 24 h and continuity at 24 h. Mean systemic arterial pressure (MAP) at 12 and 24 h was related to continuity at 12 and 24 h after birth. Multiple regression analyses revealed that RVO at 12 h was related to median EEG amplitude at 24 h and diastolic BP at 24 h was related to simultaneous EEG continuity. In addition, at 12 h, infants in the lowest quartile for RVO measurements (<282 mL/kg/min) had lower EEG amplitude and those in the lowest quartile for MAP measurements (<31 mm Hg) had lower EEG continuity. These results suggest a relationship between indirect measurements of cerebral perfusion and cerebral function soon after birth in preterm infants.

Quantitative electroencephalographic patterns in normal preterm infants over the first week after birth.

BACKGROUND: Currently available tools to assist clinicians with prediction of neurodevelopmental outcome of preterm infants are inadequate. Modified cotside electroencephalography (EEG) has the ability to produce quantitative electrophysiologic measures. These measures may be useful in future prediction of outcome. AIM: To determine patterns of change in quantitative EEG measures in preterm infants during their first week after birth. DESIGN: Observational. SUBJECTS: Preterm infants born at less than 32 weeks completed gestation surviving to discharge with unremarkable serial ultrasound scans. OUTCOME MEASURES: Changes in continuity, amplitude and spectral edge frequency measures of EEGs obtained over the first week after birth. RESULTS: Results of EEGs performed using a novel EEG device on 63 infants are reported here. Their median (range) gestation was 29 (24-31) weeks and birthweight was 1,235 (540-1,980) g. Quantitative measures of EEG continuity increased over the first week after birth from 72 (25-99)% to 92 (54-100)% at the 25 microV threshold, and from 39 (10-87)% to 64 (34-75)% at the 50 microV threshold, both p<0.0001. There was a related 32% increase in median amplitude from 5.8 (2.6-10.6) microV on day 1 to 7.6 (4.3-9.4) microV on day 4, p=0.005. There was a trend for average spectral edge frequency to fall from 10.7 (9.3-12.9) Hz on day 1 to 9.9 (8.1-12.3) Hz on day 3, p=0.06. Each gestational tertile showed similar patterns. CONCLUSIONS: There are consistent changes in quantitative neurophysiologic measures over the first week after birth, and particularly measures of continuity over the first 4 days, in normal preterm infants.

Antenatal antecedents of moderate or severe neonatal encephalopathy in term infants--a regional review.

BACKGROUND: Regional audits of term infants with neonatal encephalopathy (NE) provide an opportunity to examine issues related to causation and quality of care. AIM: To document antenatal and intrapartum antecedents in a contemporary cohort of term infants with moderate or severe neonatal encephalopathy. METHODS: Term infants admitted with moderate-severe neonatal encephalopathy over 4 years were identified. The clinical records were reviewed for information about the pregnancy and birth including interpretation of monitoring and subsequent management of the labour and delivery. RESULTS: Fifty-two maternal records were reviewed. No mothers were diabetic or had gestations > 42 weeks, but 17% of the babies were small for gestational age (SGA). The cohort had evidence of antenatal hypoxia in 15%, a sentinel event in 25% and suboptimal fetal monitoring practice in at least 42% of cases. CONCLUSIONS: Peripartum events were the major contributors to neurological damage in infants with neonatal encephalopathy. Suboptimal fetal monitoring practice and sentinel events remain the most common contributors. Ongoing education and training to address these issues should be available to all involved with intrapartum care in New Zealand.

Demographic characteristics and clinical course in infants with moderate or severe neonatal encephalopathy.

A chart review of 64 infants with moderate or severe neonatal encephalopathy showed that resuscitation was required for 61 (95%), respiratory support for 53 (83%) and anticonvulsants for 58 (91%). Death occurred in 2 (4%) infants with moderate encephalopathy and 12 (86%) with severe encephalopathy. In addition, subsequent neurodevelopment was abnormal in approximately a quarter of infants who survived after a moderate to severe encephalopathy.