Pain management, morphine administration, and outcomes in preterm infants: a review of the literature

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.

Reducing Opioid Exposure in a Level IV Neonatal Intensive Care Unit

INTRODUCTION

Infants in neonatal intensive care units require painful and noxious stimuli as part of their care. Judicious use of analgesic medications, including opioids, is necessary. However, these medications have long- and short-term side effects, including potential neurotoxicity. This quality improvement project's primary aim was to decrease opioid exposure by 33% in the first 14 days of life for infants less than 1,250 g at birth within 12 months.

METHODS

A multidisciplinary care team used Define, Measure, Analyze, Improve, Control methodology to identify root causes of the quality gap including: (1) inconsistent reporting of objective pain scales; (2) variable provider prescribing patterns; and (3) variable provider bedside assessment of pain. These root causes were addressed by two interventions: (1) standardized reporting of the premature infant pain profile scores and (2) implementation of an analgesia management pathway.

RESULTS

Mean opioid exposure, measured in morphine equivalents, in infants less than 1,250 g at birth during their first 14 days of life decreased from 0.64 mg/kg/d (95% confidence interval 0.41-0.87) at baseline to 0.08 mg/kg/d (95% confidence interval 0.03-0.13) during the postintervention period (P < 0.001). There was no statistical difference in rates of days to full feedings, unintentional extubations, or central line removals between epochs.

CONCLUSIONS

Following the implementation of consistent pain score reporting and an analgesia management pathway, opioid exposure in the first 14 days of life for infants less than 1,250 g was significantly reduced by 88%, exceeding the project aim.

Morphine affects brain activity and volumes in preterms: An observational multi-center study

OBJECTIVE

We hypothesized that morphine has a depressing effect on early brain activity, assessed using quantitative aEEG/EEG parameter and depressed activity will be associated with brain volumes at term in extremely preterm infants.

STUDY DESIGN

174 preterm infants were enrolled in 3 European tertiary NICUs (mean GA:26 ± 1wks) and monitored during the first 72 h after birth with continuous 2 channel aEEG. Six epochs of aEEG recordings were selected and minimum amplitude of aEEG (min aEEG), percentage of time amplitude <5 μV (% of time < 5 μV), spontaneous activity transients (SATrate) and interSAT interval (ISI) were calculated. For infants receiving morphine, the cumulative morphine dosage was calculated. In a subgroup of 58 infants, good quality MRI at term equivalent age (TEA) and the cumulative morphine dose until TEA were available. The effects of morphine administration and cumulative dose on aEEG/EEG measures and on brain volumes were investigated.

RESULTS

Morphine administration had a significant effect on all quantitative aEEG/EEG measures, causing depression of early brain activity [longer ISI (β 2.900), reduced SAT rate (β -1.386), decreased min aEEG (β -0.782), and increased % of time < 5 μV (β 14.802)] in all epochs. A significant effect of GA and postnatal age on aEEG/EEG measures was observed. Cumulative morphine dose until TEA had a significant negative effect on total brain volume (TBV) (β -8.066) and cerebellar volume (β -1.080).

CONCLUSIONS

Administration of sedative drugs should be considered when interpreting aEEG/EEG together with the negative dose dependent morphine impact on brain development.

Comparison of Neonatal Abstinence Syndrome Manifestations in Preterm Versus Term Opioid-Exposed Infants

BACKGROUND

Twenty percent to 40% of infants exposed to in utero opioid were delivered preterm. There is currently no neonatal abstinence syndrome (NAS) scoring tool known to accurately evaluate preterm opioid-exposed infants. This can lead to difficulties in titrating pharmacotherapy in this population.

PURPOSE

To describe NAS symptoms in preterm opioid-exposed infants in comparison with matched full-term controls.

METHODS

This was a retrospective cohort study from a single tertiary care center of methadone-exposed infants born between 2006 and 2010. Using modified Finnegan scale scores recorded every 3 to 4 hours beginning at 6 hours of life until 24 to 48 hours after medication discontinuation, NAS symptoms was compared between 45 preterm infants and 49 full-term matched controls. Concurrent neonatal medical diagnoses were also compared.

RESULTS

The median gestational age in the preterm group was 35 weeks (interquartile range [IQR] = 33-36) versus 39 weeks (IQR = 38-40) in the term group. Preterm infants scored less frequently for many items including sleep disturbance (24.4% vs 46.2%), tremors (77.9% vs 89.7%), muscle tone (87.9% vs 97.4%), sweating (2.1% vs 9.4%), nasal stuffiness (11.9% vs 20.5%), and loose stools (7.0% vs 14.3%) than full-term controls. Preterm infants scored more frequently for hyperactive moro reflex (26.4% vs 5.5%), tachypnea (19.3% vs 16.1%), and poor feeding (24.6% vs 11.8%).

IMPLICATIONS FOR PRACTICE

Provider awareness of differences in manifestations of preterm and term infants with NAS, as well as concurrent prematurity diagnoses that can influence NAS scoring, is needed. These findings mandate the development of a modified NAS scoring tool for the preterm NAS population.

IMPLICATIONS FOR RESEARCH

A preterm NAS scoring tool needs to be developed and validated to more accurately evaluate and treat preterm opioid-exposed infants.

Smaller Cerebellar Growth and Poorer Neurodevelopmental Outcomes in Very Preterm Infants Exposed to Neonatal Morphine

OBJECTIVE

To examine the relationship between morphine exposure and growth of the cerebellum and cerebrum in very preterm neonates from early in life to term-equivalent age, as well as to examine morphine exposure and brain volumes in relation to neurodevelopmental outcomes at 18 months corrected age (CA).

STUDY DESIGN

A prospective cohort of 136 very preterm neonates (24-32 weeks gestational age) was serially scanned with magnetic resonance imaging near birth and at term-equivalent age for volumetric measurements of the cerebellum and cerebrum. Motor outcomes were assessed with the Peabody Developmental Motor Scales, Second Edition and cognitive outcomes with the Bayley Scales of Infant and Toddler Development, Third Edition at 18 months CA. Generalized least squares models and linear regression models were used to assess relationships between morphine exposure, brain volumes, and neurodevelopmental outcomes.

RESULTS

A 10-fold increase in morphine exposure was associated with a 5.5% decrease in cerebellar volume, after adjustment for multiple clinical confounders and total brain volume (P = .04). When infants exposed to glucocorticoids were excluded, the association of morphine was more pronounced, with an 8.1% decrease in cerebellar volume. Morphine exposure was not associated with cerebral volume (P = .30). Greater morphine exposure also predicted poorer motor (P < .001) and cognitive outcomes (P = .006) at 18 months CA, an association mediated, in part, by slower brain growth.

CONCLUSIONS

Morphine exposure in very preterm neonates is independently associated with impaired cerebellar growth in the neonatal period and poorer neurodevelopmental outcomes in early childhood. Alternatives to better manage pain in preterm neonates that optimize brain development and functional outcomes are urgently needed.

Opioid Analgesics for Sedation and Analgesia During Mechanical Ventilation

Neonates are exposed to repetitive pain and stress during their stay in a NICU, which can lead to chronic complications related to their neurodevelopment and neurobehavior. Approximately 20 percent of all neonates in a NICU are intubated, mechanically ventilated, and require suctioning, which can cause both acute and chronic pain. Pain management in the neonate can be challenging. Nurses and other caregivers need to be well trained to assess pain in the neonate to effectively identify and provide appropriate pain management strategies. There is a lack of evidence to support routine administration of opiates in the neonate. As with any medication, the possibility of short- and long-term adverse reactions must be considered. Nonpharmacologic therapy should be used as much as possible.

Ethical challenges in neonatal intensive care nursing

BACKGROUND

Neonatal nurses report a great deal of ethical challenges in their everyday work. Seemingly trivial everyday choices nurses make are no more value-neutral than life-and-death choices. Everyday ethical challenges should also be recognized as ethical dilemmas in clinical practice.

RESEARCH OBJECTIVE

The purpose of this study is to investigate which types of ethical challenges neonatal nurses experience in their day-to-day care for critically ill newborns.

RESEARCH DESIGN

Data were collected through semi-structured qualitative in-depth interviews. Phenomenological-hermeneutic analysis was applied to interpret the data.

PARTICIPANTS AND RESEARCH CONTEXT

Six nurses from neonatal intensive care units at two Norwegian hospitals were interviewed on-site.

ETHICAL CONSIDERATIONS

The study is designed to comply with Ethical Guidelines for Nursing Research in the Nordic Countries and the Helsinki declaration.

FINDINGS

Findings suggest that nurses experience a diverse range of everyday ethical challenges related to challenging interactions with parents and colleagues, emotional strain, protecting the vulnerable infant, finding the balance between sensitivity and authority, ensuring continuity of treatment, and miscommunication and professional disagreement.

DISCUSSION

A major finding in this study is how different agents involved in caring for the newborn experience their realities differently. When these realities collide, ethical challenges arise. Findings suggest that acting in the best interests of the child becomes more difficult in situations involving many agents with different perceptions of reality.

CONCLUSION

The study presents new aspects which increases knowledge and understanding of the reality of nursing in a neonatal intensive care unit, while also demanding increased research in this field of care.

Risk predictors of opioid-induced critical respiratory events in children: naloxone use as a quality measure of opioid safety

BACKGROUND

Opioid-induced respiratory depression (OIRD) is a life-threatening complication of opioid therapy in children. Naloxone administration triggered by OIRD has been used to monitor safety of opioid therapy in adults. We used this trigger as a quality measure of opioid safety in hospitalized children to identify risk predictors of OIRD.

METHODS

We retrospectively reviewed medical records of 38 patients identified from the hospital risk management database as requiring naloxone for critical respiratory events between January 2010 and June 2012 for demographics, comorbidities, surgery, naloxone event details, and outcomes. These data were compared with baseline prevalence in contemporary patients followed by pain service, who did not receive naloxone, to calculate unadjusted odds ratios. Thematic classification of preventable events was undertaken based on analysis of each event.

RESULTS

The incidence of naloxone use among hospital inpatients, who received opioids at-least once, was 0.06% compared with 0.23% for patients on the pain service. A majority of naloxone events occurred in postoperative patients (n = 27/38, 71.1%) within the first 24 hours of surgery (n = 20/27, 75.1%) and in the critical care unit (50%). Patients undergoing airway surgeries had higher risk for OIRD (P = 0.01). Patient risk factors for naloxone use included age <1 year (P < 0.001), obstructive sleep apnea (P < 0.001), obesity (P = 0.019), being underweight (P < 0.0001), prematurity (P < 0.001), and developmental delay (P < 0.001). Majority of events (87%) were found to be preventable, which were classified into six main themes based on type of event.

CONCLUSION

OIRD is an important, albeit mostly preventable, complication of opioid therapy in children. Naloxone use can be used as a measure to track opioid safety in children, identify contributing factors, and formulate preventive strategies to reduce the risk for OIRD.