Effects of morphine and midazolam on sleep-wake cycling in amplitude-integrated electroencephalography in post-surgical neonates ≥ 32 weeks of gestational age

Postoperative EEG abnormalities in relation to neurodevelopmental outcomes after pediatric cardiac surgery

BACKGROUND

We had reported that postoperative EEG background including sleep-wake cycle (SWC) and discharge (seizures, spikes/sharp waves) abnormalities were significantly correlated with adverse early outcomes in children after cardiac surgery. We aimed to analyze the relations between these EEG abnormalities and neurodevelopmental outcomes at about 2 years after cardiac surgery.

METHODS

We enrolled 121 patients undergoing cardiac surgery at 3.3 months (0.03 ~ 28 months). EEG abnormalities described above during the first postoperative 48 h were evaluated. Griffiths Mental Development Scales-Chinese was used to evaluate the quotients of overall development and 5 subscales of the child's locomotor, language, personal-social, eye-hand coordination and performance skills at 16 ~ 31 months of age.

RESULTS

EEG background abnormalities occurred in 59/121 (48.8%) patients and 33 (55.9%) unrecovered to normal by 48 h. Abnormal SWC occurred in 15 (12.4%) patients and 7 (5.8%) unrecovered to normal by 48 h. EEG seizures occurred in 11 (9.1%) patients with frontal lobe seizures in 4. Spikes/sharp waves occurred in 100 (82.6%). EEG background abnormalities, number of spikes/sharp waves and frontal lobe seizures were significantly associated with neurodevelopmental impairment at about 1 ~ 2 year after surgery (Ps ≤ 0.05).

CONCLUSIONS

Most parameters of EEG abnormalities were significantly associated with neurodevelopmental impairment after cardiac surgery.

IMPACT

Neurodevelopmental impairment in children with congenital heart disease remain poorly understood. Previous studies had reported that either EEG seizures or background abnormalities were associated with worse neurodevelopmental outcomes. Our present study showed that all the EEG background and discharge abnormalities including EEG background, seizures and spikes/sharp waves in the early postoperative period were significantly associated with neurodevelopmental impairment at about 1 ~ 2 years after cardiac surgery. Comprehensive evaluation of early postoperative EEG may provide further insights about postoperative brain injury, its relation with neurodevelopmental impairment, and guide to improve clinical management.

Trends in Amplitude-Integrated Electroencephalography in the Smallest Preterm Neonates

BACKGROUND

Amplitude-integrated electroencephalography is increasingly used for the neuromonitoring of premature infants. However, it is still not clear how bioelectrical activity changes in the smallest gestational age newborns. The aim of our study was to evaluate the bioelectrical activity of amplitude-integrated electroencephalograms in premature newborns of different gestational age to assess how gestational age and postnatal age influence patterns of amplitude-integrated electroencephalograms and to test the hypothesis of whether the bioelectrical activity of the brain matures faster after the birth of premature newborns than in utero.

METHODS

We prospectively included infants born before 32 weeks of gestational age between June 2020 and July 2022. Serial recordings of amplitude-integrated electroencephalograms were performed at three time points of age (days 1-3, 13-15, and 27-29). Recordings were analyzed for background patterns, the onset and appearance of cyclicity, and lower amplitude border and bandwidth, which were used to derive a composite Burdjalov score.

RESULTS

In total, 140 premature neonates were included in the study, and 112 of them completed the study. The median gestational age of the newborns enrolled in the study was 29 (27-30) weeks, and the mean weight was 1206 (350) g. Burdjalov scores increased with increasing gestational age. Higher scores were observed in every dimension of the amplitude-integrated electroencephalograms for newborns of lower gestational age when compared to newborns of higher gestational age of the same postmenstrual age. There was a significant correlation between gestational age and parameters of amplitude-integrated electroencephalograms at all time points.

CONCLUSIONS

A higher gestational age has a positive effect on the bioelectrical activity of amplitude-integrated electroencephalograms. Increasing postnatal age affected amplitude-integrated electroencephalograms more than gestational age. Our hypothesis that the bioelectrical activity of the brain matures faster for premature newborns after birth than in the womb was confirmed.

Continuous electroencephalography (cEEG) in infants with congenital heart disease (CHD)

BACKGROUND

Neonates with congenital heart disease (CHD) undergoing cardiopulmonary bypass (CPB) surgery have increased risk of impaired neurodevelopmental outcomes secondary to brain injury. This study aims to characterize pre- and post-operative continuous EEG (cEEG) patterns to detect abnormal cerebral activity in infants with CHD and investigate whether an association exists between the degree of encephalopathy in pre- and post-operative cEEG.

METHODS

This retrospective cohort study conducted between 2010 and 2018 at a tertiary hospital in Cleveland, OH included infants with CHD with cEEG monitoring, who underwent CPB surgery within first 6 months of life.

RESULTS

Study included 77 patients, of which 61% were males who were operated at median age 6 days. Pre-operatively, 69% and 87% had normal cEEG and sleep-wake cycles, respectively. Post-operatively, 80% had abnormal cEEG. Longer circulatory arrest time and CPB were associated with lack of continuity (p 0.011), excessive discontinuity (p 0.007) and prolonged inter-burst interval (IBI) duration (p value < 0.001). A significant association existed between severity of encephalopathy in immediate and 24-h post-operative period (p value < 0.001).

CONCLUSIONS

More than 80% of neonates with CHD have abnormal post-operative EEG. Longer circulatory arrest time and CPB were associated with lack of continuity, excessive discontinuity, and prolonged IBI duration on post-operative EEG.

IMPACT

This study shows that majority of neonates with congenital heart disease (CHD) have normal pre-operative EEG with a continuous background and normal sleep-wake cycles. Also, 80% of neonates had abnormal post-operative EEG. Longer duration of arrest time and bypass time was associated with lack of continuity, excessive discontinuity, and prolonged IBI duration during post-operative EEG monitoring. These findings will help clinicians when counseling parents in the intensive care unit, risk stratification, and long-term neurodevelopmental monitoring in these high-risk patients.

Potential Relationship between Cerebral Fractional Tissue Oxygen Extraction (FTOE) and the Use of Sedative Agents during the Perioperative Period in Neonates and Infants

Fractional tissue oxygen extraction (FTOE) by means of cerebral near-infrared spectroscopy (NIRS) provides information about oxygen uptake in the brain. Experimental animal data suggest that sedative agents decrease cerebral oxygen demand. The aim of the present study was to investigate the association between the cerebral FTOE and the use of pre and intraoperative sedative agents in infants aged 1-90 days. Cerebral NIRS was continuously applied during open major non-cardiac surgery in 46 infants. The main outcomes were the mean intraoperative FTOE and the percentage (%) of time of intraoperative hyperoxia_FTOE relative to the total duration of anesthesia. Hyperoxia_FTOE was defined as FTOE ≤ 0.1. Cumulative doses of sedative agents (benzodiazepines and morphine), given up to 24 h preoperatively, correlated with the mean intraoperative FTOE (Spearman's rho = -0.298, p = 0.0440) and were predictive for the % of time of intraoperative hyperoxia_FTOE (β (95% CI) 47.12 (7.32; 86.92)) when adjusted for the patients' age, type of surgery, preoperative hemoglobin, intraoperative sevoflurane and fentanyl dose, mean intraoperative arterial blood pressure, and end-tidal CO₂ by multivariate 0.75 quantile regression. There was no association with 0.5 quantile regression. We observed the suggestive positive association of decreased fractional cerebral tissue oxygen extraction and the use of sedative agents in neonates and infants undergoing surgery.

The Prognostic Value of Early Amplitude-Integrated Electroencephalography Monitoring After Pediatric Cardiac Arrest

OBJECTIVES

To assess the ability of amplitude-integrated electroencephalography monitoring within 24 hours of the return of spontaneous circulation to prognosticate neurologic outcomes in children following cardiac arrest DESIGN:: Retrospective review of prospectively recorded data. An amplitude-integrated electroencephalography background score was calculated according to background activity during the first 24 hours after return of spontaneous circulation, a higher score correlating with more impaired background activity. The primary endpoint was the neurologic outcome as defined by the Pediatric Cerebral Performance Category at PICU discharge (Pediatric Cerebral Performance Category 1-3: a good neurologic outcome; Pediatric Cerebral Performance Category 4-6: a poor neurologic outcome).

SETTING

A referral PICU.

PATIENTS

Thirty children with a median age of 10 months (2-38 mo) and a male/female sex ratio of 1.3 were included.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Eighteen patients were assigned to the favorable outcome group and 12 to the unfavorable outcome group. The median time between return of spontaneous circulation and amplitude-integrated electroencephalography initiation was 4 hours (3-9 hr). The amplitude-integrated electroencephalography score within 24 hours after return of spontaneous circulation was significantly higher in the children with poor outcomes compared with those with good outcomes (12 ± 4 vs 25 ± 8; p < 0.001). Background activity during amplitude-integrated electroencephalography monitoring was able to predict poor neurologic outcomes at PICU discharge, with an area under the receiver operating characteristic curve of 0.91 (95% CI, 0.81-1.00).

CONCLUSIONS

Early amplitude-integrated electroencephalography monitoring may help predict poor neurologic outcomes in children within 24 hours following cardiac arrest.

Amplitude-integrated EEG in infants with neonatal abstinence syndrome

BACKGROUND

To describe amplitude-integrated encephalogram (aEEG) characteristics of neonates with neonatal abstinence syndrome (NAS).

METHODS

This is a prospective observational study. Newborns exposed to prenatal opioids and their gestational matched controls were included. A single-channel aEEG was obtained using Olympic 6000 CFM monitor. The background activity (continuous/discontinuous), the amplitudes (μV) and the presence of sleep-wake cycle (SWC) were documented.

RESULTS

A total of 59 infants, 23 with NAS and 36 controls were enrolled. All aEEG were completed within 48 hours of life prior to initiation of treatment. Birth weight and gestational age were similar in both groups. An aEEG was abnormal (discontinuous pattern and/or absent SWC) in 78 % (18/23) of infants with NAS versus only 25% in control group (9/36), [OR 10.8, CI (2.7-46.5) P < 0.001]. 61% of infants with NAS had discontinuous pattern [OR 7.8, CI (2-32) P = 0.001] and 39% had absence of sleep-wake cycle [OR 7.1, CI (1.4-39.4) P = 0.007].

CONCLUSIONS

A majority of infants with NAS have abnormal aEEG activity.

The power of N-PASS, aEEG, and BIS in detecting different levels of sedation in neonates: A preliminary study

BACKGROUND

Sedatives are essential drugs in every intensive care unit in order to ensure the patient's optimal level of comfort. Avoiding conditions of over- and under-sedation is a challenge in a neonatal intensive care setting. Drug administration could be optimized by the concomitant use of objective methods to assess the level of sedation.

AIMS

We aimed to look at the ability of different methods (Neonatal Pain, Agitation and Sedation Scale, amplitude-integrated Electroencephalogram, and Bispectral Index), and their combination, in detecting different level of sedation.

METHODS

Twenty-seven neonates among whom 17 were receiving sedatives with or without opiate analgesics were monitored using the Neonatal Pain, Agitation and Sedation Scale, the amplitude-integrated Electroencephalogram, and the Bispectral Index. According to the expert opinion of two trained neonatologists, patients were categorized into three groups: no, light, and deep sedation. Four hours of simultaneous assessment of the Neonatal Pain, Agitation and Sedation Scale scores, Burdjalov scores (to summarize the amplitude-integrated Electroencephalogram trace), and Bispectral Index values were considered for the comparative analysis across these groups.

RESULTS

All three methods could differentiate patients who were not sedated from those who were deeply sedated: median score 12 and 9, respectively, (95% CI of difference = 1.99-5.99, P = 0.001) for the amplitude-integrated Electroencephalogram Burdjalov score; median 1 and -5, respectively, (95% CI of difference = 2.99-8.00, P = 0.001) for the Neonatal Pain, Agitation and Sedation Scale; and median 48 and 37, respectively, (CI of difference = 1.77-22.00, P = 0.043) for the Bispectral Index. However none of them, used alone, was able to differentiate light and deep sedation: median score 10 and 9, respectively, for the amplitude-integrated Electroencephalogram Burdjalov score; median -2 and -5, respectively, for the Neonatal Pain, Agitation and Sedation Scale; and median 48 and 37, respectively, for the Bispectral Index. Only the amplitude-integrated Electroencephalogram and the Neonatal Pain, Agitation and Sedation Scale were able to differentiate between the conditions of no sedation and light sedation. Also, according to the area under the curves values, the combination of the Neonatal Pain, Agitation and Sedation Scale with the Burdjalov score derived from the amplitude-integrated Electroencephalogram showed the best accuracy in differentiating light and deep sedation.

CONCLUSION

While none of the three methods alone was able to precisely differentiate between different levels of sedation, we suggest that using a combination of amplitude-integrated Electroencephalogram and Neonatal Pain, Agitation and Sedation Scale can be useful to distinguish between light and deep sedation in neonatal patients.

Amplitude-integrated electroencephalography during the first 72 h after birth in neonates diagnosed prenatally with congenital heart disease

BackgroundLittle is known on amplitude-integrated electroencephalography (aEEG) during the first few days after birth in neonates with congenital heart disease (CHD). Our aim was, therefore, to assess electrocortical activity using aEEG within the first 72 h after birth in neonates diagnosed prenatally with CHD, and to define independent prenatal and postnatal predictors for abnormal aEEG.MethodsNeonates with CHD who were admitted to the neonatal intensive care unit between 2010 and 2017 were retrospectively included. We assessed aEEG background patterns, sleep-wake cycling, and epileptic activity during the first 72 h after birth and defined prenatal and postnatal clinical parameters associated with aEEG patterns.ResultsSeventy-two neonates were included. Twenty-six (36%) had mildly abnormal and six (8%) had severely abnormal aEEG background patterns at some point during the study period. Sleep-wake cycling was present in 97% of the neonates. Subclinical seizures were common (15%), whereas none of the neonates had clinical seizures. Only treatment with sedatives was a significant predictor for abnormal aEEG background patterns, explaining 56% of the variance.ConclusionAbnormal aEEG background patterns are common and are strongly associated with treatment with sedatives in neonates with prenatally diagnosed CHD. Future studies should assess the association between early postnatal aEEG abnormalities and neurodevelopmental outcome.

Investigation of EEG Activity Compared with Mean Arterial Blood Pressure in Extremely Preterm Infants

Background

Cerebral electrical activity in extremely preterm infants is affected by various factors including blood gas and circulatory parameters.

Objective

To investigate whether continuously measured invasive mean arterial blood pressure (BP) is associated with electroencephalographic (EEG) discontinuity in extremely preterm infants.

Study design

This prospective observational study examined 51 newborn infants born <29 weeks gestation in the first 3 days after birth. A single channel of raw EEG was used to quantify discontinuity. Mean BP was acquired using continuous invasive measurement and Doppler ultrasound was used to measure left ventricular output (LVO) and common carotid artery blood flow (CCAF).

Results

Median gestation and birthweight were 25.6 weeks and 760 g, respectively. Mean discontinuity reduced significantly between days 1 and 3. EEG discontinuity was significantly related to gestation, pH and BP. LVO and CCAF were not associated with EEG discontinuity.

Conclusion

Continuously measured invasive mean arterial BP was found to have a negative relationship with EEG discontinuity; increasing BP was associated with lower EEG discontinuity. This did not appear to be mediated by surrogates of systemic or cerebral blood flow. Infants receiving inotropic support had significantly increased EEG discontinuity on the first day after birth.

Amplitude-integrated EEG in newborns with critical congenital heart disease predicts preoperative brain magnetic resonance imaging findings

OBJECTIVE

The study aims are to evaluate cerebral background patterns using amplitude-integrated electroencephalography in newborns with critical congenital heart disease, determine if amplitude-integrated electroencephalography is predictive of preoperative brain injury, and assess the incidence of preoperative seizures. We hypothesize that amplitude-integrated electroencephalography will show abnormal background patterns in the early preoperative period in infants with congenital heart disease that have preoperative brain injury on magnetic resonance imaging.

METHODS

Twenty-four newborns with congenital heart disease requiring surgery at younger than 30 days of age were prospectively enrolled within the first 3 days of age at a tertiary care pediatric hospital. Infants had amplitude-integrated electroencephalography for 24 hours beginning close to birth and preoperative brain magnetic resonance imaging. The amplitude-integrated electroencephalographies were read to determine if the background pattern was normal, mildly abnormal, or severely abnormal. The presence of seizures and sleep-wake cycling were noted. The preoperative brain magnetic resonance imaging scans were used for brain injury and brain atrophy assessment.

RESULTS

Fifteen of 24 infants had abnormal amplitude-integrated electroencephalography at 0.71 (0-2) (mean [range]) days of age. In five infants, the background pattern was severely abnormal. (burst suppression and/or continuous low voltage). Of the 15 infants with abnormal amplitude-integrated electroencephalography, 9 (60%) had brain injury. One infant with brain injury had a seizure on amplitude-integrated electroencephalography. A severely abnormal background pattern on amplitude-integrated electroencephalography was associated with brain atrophy (P = 0.03) and absent sleep-wake cycling (P = 0.022).

CONCLUSION

Background cerebral activity is abnormal on amplitude-integrated electroencephalography following birth in newborns with congenital heart disease who have findings of brain injury and/or brain atrophy on preoperative brain magnetic resonance imaging.

Behavioral observation differentiates the effects of an intervention to promote sleep in premature infants: a pilot study

PURPOSE

Sleep and ongoing cycling of sleep states are required for neurosensory processing, learning, and brain plasticity. Many aspects of neonatal intensive care environments such as handling for routine and invasive procedures, bright lighting, and noise can create stress, disrupt behavior, and interfere with sleep in prematurely born infants. The study empirically investigated whether a 30-minute observation of infant sleep states and behavior could differentiate an intervention to promote sleep in premature infants with feeding difficulties relative to conventional care (standard positioning, standard crib mattress [SP]). We included an intervention to determine the ability of the method to discriminate treatments and generate a benchmark for future improvements. The intervention, a conformational positioner (CP), is contoured around the infant to provide customized containment and boundaries. To more fully verify the 30-minute observational sleep results, standard polysomnography was conducted simultaneously and sleep outcomes for the 2 modalities were compared.

SUBJECTS

In a randomized crossover clinical trial, 25 infants, 31.5 ± 0.6 weeks' gestational age and 38.4 ± 0.6 weeks at the study, with gastrointestinal conditions or general feeding difficulties used each intervention during an overnight neonatal intensive care unit sleep study.

METHODS

Infant sleep states and behaviors were observed during two 30-minute periods--that is, on the positioner and mattress--using the naturalistic observation of newborn behavior. Two certified developmental care nurses assessed sleep state, self-regulatory, and stress behaviors during 2-minute intervals and summed over 30 minutes. Sleep characteristics from standard polysomnography were measured at the time of behavior observations.

RESULTS

Infants on CP spent significantly less time in alert, active awake, or crying states by observation compared with SP. Surgical subjects spent more time awake, active awake, or crying and displayed a higher number of behavior state changes than the nonsurgical infants. The percentage of time in observed deep sleep and quiet sleep was correlated with both percentage sleep efficiency (r = 0.78) and fewer state shifts per hour (r = -0.65) from electroencephalogram (EEG). Sleep efficiency by EEG was greater on CP versus SP.

CONCLUSIONS

The CP enabled sleep compared with the standard mattress (SP) over 30-minute observation periods. Sleep status from behavioral observation was verified by standard EEG-based sleep techniques. Behavioral observation of sleep states may be a useful strategy for measuring the effectiveness of strategies to facilitate sleep in premature infants. Surgical subjects may benefit from additional interventions to promote sleep.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Pain assessment and measurement in neonates: an updated review

Pain assessment and measurement are the cornerstones of pain management. Pain assessment connotes a comprehensive multidimensional description. Conversely, pain measurement provides a numeric quantitative description of each factor illustrating pain qualities. Pain scales provide a composite score used to guide practice and research. The type of infant pain instrument chosen is a significant factor in guiding pain management practice. The purpose of this review was to summarize current infant pain measures by introducing a conceptual framework for pain measurement. Although more than 40 infant pain instruments exist, many were devised solely for research purposes; several of the newly developed instruments largely overlap with existing instruments. Integration of pain management into daily practice remains problematic. Understanding how each instrument measures infant pain allows clinicians to make better decisions about what instrument to use with which infant and in what circumstances. In addition, novel new measurement techniques need further testing.

Quantification of neonatal amplitude-integrated EEG patterns

BACKGROUND

Amplitude-integrated EEG (aEEG) is increasingly used in research with premature infants; however, comprehensive interpretation is limited by the lack of simple approaches for reliably quantifying and summarizing the data.

AIM

Explore operational measures for quantifying continuity and discontinuity, measured by aEEG as components of infant brain function.

STUDY DESIGN

An exploratory naturalistic study of neonates while in the Neonatal Intensive Care Unit (NICU). One single channel aEEG recording per infant was obtained without disruption of nursing care practices.

SUBJECTS

24 infants with mean postmenstrual age (PMA) of 33.11 weeks (SD 3.49), average age of 2.62 weeks (SD 1.35) and mean birth weights of 1.39 kg (SD 0.73).

OUTCOME MEASURES

Quantification of continuity and discontinuity included bandwidth and lower border of aEEG, calculated proportion of time with signal amplitude below 10 μV, and peak counts. Variance of bandwidth and lower border denoted cycling.

RESULTS

Group mean bandwidth was 52.98 μV (SD 27.62). Median peak count in 60 second epochs averaged 3.63 (SD 1.74), while median proportion < 10 μV was 22% (SD 0.20). The group mean of lower border within-subject aggregated medians was 6.20 μV (SD 2.13). Group mean lower border standard deviation was 3.96 μV. Proportion < 10 μV showed a strong negative correlation with the natural log of the lower border median (r = -0.906, p < .0001) after controlling for PMA.

CONCLUSIONS

This study introduces a novel quantification process by counting peaks and proportion of time < 10 μV. Expanded definitions and analytic techniques will serve to strengthen the application of existing scoring systems for use in naturalistic research settings and clinical practice.

Amplitude-integrated electroencephalography in male newborns <30 weeks' of gestation and unfavourable neurodevelopmental outcome at three years is less mature when compared to females

AIM

To investigate gender-related differences in amplitude-integrated electroencephalography (aEEG) associated with neurodevelopmental outcome at 3 years.

METHODS

Preterms born <30 weeks' gestational age between 2000 and 2002 were prospectively included. aEEGs obtained within the first 2 weeks of life were classified according to aEEG composite scores - including background pattern, sleep-wake cycling (SWC) and seizure activity. Neurodevelopmental outcome was assessed at 3 years of age.

RESULTS

Neurodevelopmental outcome data was available for 148 of 264 eligible infants - 64 showed a normal outcome and 84 an impaired outcome. A logistic regression model revealed a significant independent influence of IVH, analgetic/sedative/anticonvulsant medication, gestational age and gender on aEEG composite scores. Odds ratios for having an abnormal aEEG composite score within the first 2 weeks of life for 'female sex', 'no IVH', 'no medication' and 'gestational age' were calculated. aEEG did not differ between males and females with normal outcomes. In patients with abnormal outcome, however, male preterms showed more burst-suppression patterns and less SWC when compared with female preterms.

CONCLUSION

Being male with an abnormal outcome at 3 years of age is reflected by a less mature early aEEG when compared with the one of females. This association is independent of IVH and medication and was less evident with increasing gestational age.