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.

Bispectral index and lower margin amplitude of the amplitude-integrated electroencephalogram in neonates.

BACKGROUND: The lower margin amplitude (LMA) of the amplitude-integrated electroencephalogram (aEEG) is suppressed in neonates during deep sedation, a feature that is attributed to the bispectral index (BIS) in adults. OBJECTIVE: We compare the BIS and the LMA of the aEEG in neonates. METHODS: Thirty neurologically healthy neonates between 37 and 44 weeks postmenstrual age were included in this study. Twenty patients received sedoanalgesic therapy for various reasons. BIS and aEEG recordings were performed simultaneously. The digital data were imported in the numerical software environment Matlab®. The LMA of the aEEG was computed on a 1-min time scale and synchronized with the BIS data. The correlation between the time-dependent variables BIS and LMA was estimated using the Spearman rank correlation index. RESULTS: The median correlation between BIS and LMA was 0.3. Inclusion of recordings of high signal quality only into analysis improved the median correlation index to 0.6. CONCLUSIONS: We found a light-to-moderate correlation between BIS and LMA in our study cohort and a good correlation in the subgroup with high signal quality.

Successful implementation of a neonatal pain and sedation protocol at 2 NICUs.

OBJECTIVE: To evaluate the implementation of a neonatal pain and sedation protocol at 2 ICUs. METHODS: The intervention started with the evaluation of local practice, problems, and staff satisfaction. We then developed and implemented the Vienna Protocol for Neonatal Pain and Sedation. The protocol included well-defined strategies for both nonpharmacologic and pharmacologic interventions based on regular assessment of a translated version of the Neonatal Pain Agitation and Sedation Scale and titration of analgesic and sedative therapy according to aim scores. Health care staff was trained in the assessment by using a video-based tutorial and bedside teaching. In addition, we performed reevaluation, retraining, and random quality checks. Frequency and quality of assessments, pharmacologic therapy, duration of mechanical ventilation, and outcome were compared between baseline (12 months before implementation) and 12 months after implementation. RESULTS: Cumulative median (interquartile range) opiate dose (baseline dose of 1.4 [0.5-5.9] mg/kg versus intervention group dose of 2.7 [0.4-57] mg/kg morphine equivalents; P = .002), pharmacologic interventions per episode of continuous sedation/analgesia (4 [2-10] vs 6 [2-13]; P = .005), and overall staff satisfaction (physicians: 31% vs 89%; P < .001; nurses: 17% vs 55%; P < .001) increased after implementation. Time on mechanical ventilation, length of stay at the ICU, and adverse outcomes were similar before and after implementation. CONCLUSIONS: Implementation of a neonatal pain and sedation protocol at 2 ICUs resulted in an increase in opiate prescription, pharmacologic interventions, and staff satisfaction without affecting time on mechanical ventilation, length of intensive care stay, and adverse outcomes.

Can neurophysiological assessment improve timing of intervention in posthaemorrhagic ventricular dilatation?

OBJECTIVE: Intraventricular haemorrhage is still the most common cause of brain lesion in preterm infants and development of a posthaemorrhagic ventricular dilatation (PHVD) can lead to additional neurological sequelae. Flash visual evoked potentials (fVEP) and amplitude-integrated electroencephalography (aEEG) are non-invasive neurophysiological monitoring tools. The aim of the study was to evaluate fVEPs and aEEGs in preterm infants with progressive PHVD prior to and after neurosurgical intervention for cerebrospinal fluid removal and to correlate the findings with severity of ventricular dilatation. DESIGN: fVEPs and aEEGs were performed weekly in infants with developing PHVD. As soon as the ventricular index reached the 97th percentile recordings were performed twice a week. METHODS: 17 patients admitted to the neonatal intensive care unit of the Medical University of Vienna who developed progressive PHVD were evaluated using fVEP and aEEG until and after reduction of intracranial pressure by placement of an external ventricular drainage. RESULTS: In all 17 cases (100%) wave latencies of fVEP increased above normal range and aEEG showed increased suppression in 13 patients (76%) with increasing ventricular dilatation. Both methods showed normalisation of patterns mostly within a week of successful therapeutic intervention (mean 8.5 days). Both changes in fVEP latencies and aEEG background patterns were detected before clinical signs of elevated intracranial pressure occurred. In only 10 patients (58.8%) ventricular width exceeded the 97th percentile+4 mm. CONCLUSIONS: fVEP and aEEG are useful additional tools for the evaluation of preterm infants with progressive PHVD.