Effect of increased opiate exposure on three years neurodevelopmental outcome in extremely preterm infants

Neuroprotective therapies in the NICU in preterm infants: present and future (Neonatal Neurocritical Care Series)

The survival of preterm infants has steadily improved thanks to advances in perinatal and neonatal intensive clinical care. The focus is now on finding ways to improve morbidities, especially neurological outcomes. Although antenatal steroids and magnesium for preterm infants have become routine therapies, studies have mainly demonstrated short-term benefits for antenatal steroid therapy but limited evidence for impact on long-term neurodevelopmental outcomes. Further advances in neuroprotective and neurorestorative therapies, improved neuromonitoring modalities to optimize recruitment in trials, and improved biomarkers to assess the response to treatment are essential. Among the most promising agents, multipotential stem cells, immunomodulation, and anti-inflammatory therapies can improve neural outcomes in preclinical studies and are the subject of considerable ongoing research. In the meantime, bundles of care protecting and nurturing the brain in the neonatal intensive care unit and beyond should be widely implemented in an effort to limit injury and promote neuroplasticity. IMPACT: With improved survival of preterm infants due to improved antenatal and neonatal care, our focus must now be to improve long-term neurological and neurodevelopmental outcomes. This review details the multifactorial pathogenesis of preterm brain injury and neuroprotective strategies in use at present, including antenatal care, seizure management and non-pharmacological NICU care. We discuss treatment strategies that are being evaluated as potential interventions to improve the neurodevelopmental outcomes of infants born prematurely.

Pain and neurodevelopmental outcomes of infants born very preterm

AIM

To investigate the impact of the level of pain experienced by infants born preterm on neurodevelopmental outcomes during their stay in a neonatal intensive care unit.

METHOD

In this retrospective data analysis we included all surviving infants born preterm with a gestational age between 23 and 32 weeks from 2011 to 2015, who were assessed using the Neonatal Pain, Agitation, and Sedation Scale and examined at 1 year of age using the Bayley Scales of Infant Development. We excluded all infants who had suffered severe neurological morbidities and undergone surgical interventions.

RESULTS

A total of 196 infants born preterm were included in the analyses: 105 in the 'no pain group' and 91 in the 'pain group'. Significant differences between the groups were detected for both mental and motor development (p = 0.003, 95% confidence interval [CI] 2.23-10.92; p = 0.025, 95% CI 0.64-9.78). The results remained significant after controlling for other important medical conditions (p = 0.001, 95% CI -19.65 to -5.40; p = 0.010, 95% CI -16.18 to -2.29).

INTERPRETATION

Neonatal pain exposure was associated with altered neurodevelopmental outcomes of infants born very preterm at a corrected age of 12 months. This observation highlights the importance of adequate pain management to reduce the risk of poor neurodevelopmental outcomes in these vulnerable patients.

Early-life exposure to analgesia and 18-month neurodevelopmental outcomes in very preterm infants

BACKGROUND

We assessed variability of analgesic use across three tertiary neonatal intensive care units (NICUs) accounting for early-life pain, quantified as number of invasive procedures. We also determined whether analgesia exposure modifies associations between early-life pain and neurodevelopment.

METHODS

Multicenter prospective study of 276 very preterm infants (born <24-32 weeks' gestational age [GA]). Detailed data of number of invasive procedures and duration of analgesia exposure were collected in initial weeks after birth. Eighteen-month neurodevelopmental assessments were completed in 215 children with Bayley Scales for Infant Development-Third edition.

RESULTS

Multivariable linear regressions revealed significant differences in morphine use across sites, for a given exposure to early-life pain (interaction p < 0.001). Associations between early-life pain and motor scores differed by duration of morphine exposure (interaction p = 0.01); greater early-life pain was associated with poorer motor scores in infants with no or long (>7 days) exposure, but not short exposure (≤7 days).

CONCLUSIONS

Striking cross-site differences in morphine exposure in very preterm infants are observed even when accounting for early-life pain. Negative associations between greater early-life pain and adverse motor outcomes were attenuated in infants with short morphine exposure. These findings emphasize the need for further studies of optimal analgesic approaches in preterm infants.

IMPACT

In very preterm neonates, both early-life exposure to pain and analgesia are associated with adverse neurodevelopment and altered brain maturation, with no clear guidelines for neonatal pain management in this population. We found significant cross-site variability in morphine use across three tertiary neonatal intensive care units in Canada. Morphine use modified associations between early-life pain and motor outcomes. In infants with no or long durations of morphine exposure, greater early-life pain was associated with lower motor scores, this relationship was attenuated in those with short morphine exposure. Further trials of optimal treatment approaches with morphine in preterm infants are warranted.

The consequences of neonatal pain, stress and opiate administration in animal models: An extensive meta-analysis concerning neuronal cell death, motor and behavioral outcomes

This systematic review and meta-analysis aimed to investigate the association of neonatal exposure to pain, stress, opiate administration alone, as well as opiate administration prior to a painful procedure on neuronal cell death, motor, and behavioral outcomes in rodents. In total, 36 studies investigating the effect of pain (n = 18), stress (n = 15), opiate administration (n = 13), as well as opiate administration prior to a painful event (n = 7) in rodents were included in our meta-analysis. The results showed a large effect of pain (g = 1.37, 95% CI 1.00-1.74, p < .001) on neuronal cell death. Moreover, higher number of neonatal pain events were significantly associated with increased neuronal cell death, increased anxiety (b = -1.18, SE = 0.43, p = .006), and depressant-like behavior (b = 1.74, SE = 0.51, p = .027) in rodents. Both opiates and pain had no impact on motor function (g = 0.26, 95% CI 0.18-0.70, p = .248).

Long-term impact of systematic pain and sedation management on cognitive, motor, and behavioral outcomes of extremely preterm infants at preschool age

BACKGROUND

Providing optimal pain relief is a challenging task when caring for premature infants. The aim of this study was to compare the long-term cognitive, motor, and behavioral outcomes of preterm infants before and after the implementation of a pain and sedation protocol. In addition, we investigated whether the increased opiate administration resulting after the implementation process had an impact on these outcomes.

METHODS

Cognitive outcomes were evaluated using the Kaufman Assessment Battery for Children (KABC), neuromotor examinations were based on Amiel-Tison, and behavioral outcomes were assessed using the parent-reported Child Behavior Checklist (CBCL).

RESULTS

One hundred extremely preterm infants were included in the study (control group, n = 53; intervention group, n = 47). No significant differences were found in cognitive and motor outcomes at preschool age. However, every increase in the cumulative opiate exposure for each 100 mg/kg was weakly significantly associated with a higher risk for autism spectrum features (adjusted odds ratio (aOR) = 1.822, 95% confidence interval (CI) [1.231-2.697]; P = 0.03) and withdrawn behavior (aOR = 1.822, 95% CI [1.231-2.697]; P = 0.03) at preschool age.

CONCLUSION

Increased neonatal cumulative opiate exposure did not alter cognitive and motor outcomes but may represent a risk factor for autism spectrum and withdrawn behavior at preschool age.

IMPACT

The implementation of a protocol for the management of pain and sedation in preterm infants resulted in increased cumulative opiate exposure. Our study adds further evidence that increased neonatal opiate exposure did  not alter cognitive and motor outcomes but may yield a potential risk factor for autism spectrum disorders and withdrawn behavior at preschool age. A vigilant use of opiates is recommended. Further studies are needed looking for novel pain management strategies and drugs providing optimal pain relief with minimal neurotoxicity.

Morphine use in the neonatal period and later neuropsychological development: a systematic review

AIM

To identify and evaluate the evidence documenting the association between neonatal morphine and later childhood neuropsychological development.

METHOD

We conducted a systematic literature search of eight electronic databases from inception until June 2019. We included all randomized controlled trials (RCTs) and cohort studies recruiting neonates who received morphine treatment, and measuring neuropsychological development outcomes with a minimum follow-up of 6 months.

RESULTS

Twelve separate reports from three RCTs and five cohort studies met our inclusion criteria. Owing to the small number of the included trials and the variable study designs, a meta-analysis was not performed. The findings from this review indicated that neonatal morphine use had no adverse effects on behaviour, cognition, motor, and executive function development at 8 to 9 years and earlier; except for the inconsistent conclusions on internalizing behavioural problems at 5 to 7 years and cognitive and motor developments at 18 months.

INTERPRETATION

Why a child needs morphine may have a more profound impact on later neuropsychological development than morphine itself. The small number, high heterogeneity, and limitations of the included studies limit confidence in the result of this systematic review.

Neonatal Pain, Agitation, and Sedation Scale's use, reliability, and validity: a systematic review

The Neonatal Pain, Agitation, and Sedation Scale (N-PASS) is recommended by the American Academy of Pediatrics to measure neonatal pain and sedation. However, little is known regarding its reliability and validity for diverse neonatal subpopulations. Twenty-nine studies were included in our review, demonstrating broad application of N-PASS and good or excellent reliability and validity for various neonatal subpopulations. Our systematic review found N-PASS to be valid and reliable for many but not all neonatal subpopulations. There is a lack of support for N-PASS reliability and validity for measuring prolonged pain and sedation in nonmechanically ventilated infants and for acute pain in postoperative infants in any gestational age category. Overall, N-PASS is a psychometrically sound and pragmatic instrument evaluating pain and sedation for most neonatal populations. Future research using N-PASS is encouraged to evaluate and report its validity and reliability, especially for neonatal subpopulations not included in this review.

Therapeutic hypothermia and N-PASS; results from implementation in a level 3 NICU

BACKGROUND

Neonates that have been subjected to perinatal asphyxia and fulfill criteria for therapeutic hypothermia are cooled to 33.5 °C for 72 h. There is no consensus regarding sedation and analgesic use during hypothermia, but there is evidence supporting the importance of pain relief and adequate sedation. There is a need for assessment of the neonates need for pain relief and sedation, and for adjustments of medication to ensure adequate treatment. There are many different scoring tools available. We found the N-PASS (Neonatal Pain, Agitation and Sedation Scale) scoring tool to be the most suitable for this patient group as it assesses both pain and sedation.

METHODS

We translated the scoring tool according to guidelines published by Wilder et al., and scored neonates treated with therapeutic hypothermia. Sedation and analgesia were adjusted according to scoring results. At the end of the study a questionnaire was filled out by the nurses in charge of this group of patients.

RESULTS

Both pain and sedation scores did not reach the desired levels until day 3. The nurses reported a high level of satisfaction (79.7% were extremely of very satisfied), and 96.7% of the nurses found the neonates to be better pain relieved after the initiation of the study.

CONCLUSION

The implementation of the N-PASS scoring tool in our unit has been successful, and has led to better pain relief and sedation than before the implementation.