Analgosedation with low-dose morphine for preterm infants with CPAP: risks and benefits

Premedication before laryngoscopy in neonates: Evidence-based statement from the French society of neonatology (SFN)

CONTEXT

Laryngoscopy is frequently required in neonatal intensive care. Awake laryngoscopy has deleterious effects but practice remains heterogeneous regarding premedication use. The goal of this statement was to provide evidence-based good practice guidance for clinicians regarding premedication before tracheal intubation, less invasive surfactant administration (LISA) and laryngeal mask insertion in neonates.

METHODS

A group of experts brought together by the French Society of Neonatology (SFN) addressed 4 fields related to premedication before upper airway access in neonates: (1) tracheal intubation; (2) less invasive surfactant administration; (3) laryngeal mask insertion; (4) use of atropine for the 3 previous procedures. Evidence was gathered and assessed on predefined questions related to these fields. Consensual statements were issued using the GRADE methodology.

RESULTS

Among the 15 formalized good practice statements, 2 were strong recommendations to do (Grade 1+) or not to do (Grade 1-), and 4 were discretionary recommendations to do (Grade 2+). For 9 good practice statements, the GRADE method could not be applied, resulting in an expert opinion. For tracheal intubation premedication was considered mandatory except for life-threatening situations (Grade 1+). Recommended premedications were a combination of opioid + muscle blocker (Grade 2+) or propofol in the absence of hemodynamic compromise or hypotension (Grade 2+) while the use of a sole opioid was discouraged (Grade 1-). Statements regarding other molecules before tracheal intubation were expert opinions. For LISA premedication was recommended (Grade 2+) with the use of propofol (Grade 2+). Statements regarding other molecules before LISA were expert opinions. For laryngeal mask insertion and atropine use, no specific data was found and expert opinions were provided.

CONCLUSION

This statement should help clinical decision regarding premedication before neonatal upper airway access and favor standardization of practices.

Physiologically based pharmacokinetic/pharmacodynamic model for the prediction of morphine brain disposition and analgesia in adults and children

Morphine is a widely used opioid analgesic, which shows large differences in clinical response in children, even when aiming for equivalent plasma drug concentrations. Age-dependent brain disposition of morphine could contribute to this variability, as developmental increase in blood-brain barrier (BBB) P-glycoprotein (Pgp) expression has been reported. In addition, age-related pharmacodynamics might also explain the variability in effect. To assess the influence of these processes on morphine effectiveness, a multi-compartment brain physiologically based pharmacokinetic/pharmacodynamic (PB-PK/PD) model was developed in R (Version 3.6.2). Active Pgp-mediated morphine transport was measured in MDCKII-Pgp cells grown on transwell filters and translated by an in vitro-in vivo extrapolation approach, which included developmental Pgp expression. Passive BBB permeability of morphine and its active metabolite morphine-6-glucuronide (M6G) and their pharmacodynamic parameters were derived from experiments reported in literature. Model simulations after single dose morphine were compared with measured and published concentrations of morphine and M6G in plasma, brain extracellular fluid (ECF) and cerebrospinal fluid (CSF), as well as published drug responses in children (1 day– 16 years) and adults. Visual predictive checks indicated acceptable overlays between simulated and measured morphine and M6G concentration-time profiles and prediction errors were between 1 and -1. Incorporation of active Pgp-mediated BBB transport into the PB-PK/PD model resulted in a 1.3-fold reduced brain exposure in adults, indicating only a modest contribution on brain disposition. Analgesic effect-time profiles could be described reasonably well for older children and adults, but were largely underpredicted for neonates. In summary, an age-appropriate morphine PB-PK/PD model was developed for the prediction of brain pharmacokinetics and analgesic effects. In the neonatal population, pharmacodynamic characteristics, but not brain drug disposition, appear to be altered compared to adults and older children, which may explain the reported differences in analgesic effect.

Developmental processes in children can affect pharmacokinetics: “what the body does to the drug” as well as pharmacodynamics: “what the drug does to the body”. A typical example is morphine, of which the analgesic response is variable and particularly neonates suffer more often from respiratory depression, even when receiving doses corrected for differences in elimination. One way to mathematically incorporate developmental processes is by employing physiologically based pharmacokinetic/pharmacodynamic (PB-PK/PD) models, where physiological differences between individuals are incorporated. In this study, we developed a morphine PB-PK/PD model to predict brain drug disposition as well as analgesic response in adults and children, as both processes could potentially contribute to developmental variability in the effect of morphine. We found that age-related variation in BBB expression of the main morphine efflux transporter P-glycoprotein was not responsible for differences in brain exposure. In contrast, pharmacodynamic modelling suggested an increased sensitivity to morphine in neonates.

Comparative safety profile of chloral hydrate versus other sedatives for procedural sedation in hospitalized infants

BACKGROUND

Given the limited available evidence on chloral hydrate safety in neonatal populations and the discrepancy in chloral hydrate acceptance between the US and other countries, we sought to clarify the safety profile of chloral hydrate compared to other sedatives in hospitalized infants.

METHODS

We included all infants <120 days of life who underwent a minor procedure and were administered chloral hydrate, clonidine, clonazepam, dexmedetomidine, diazepam, ketamine, lorazepam, midazolam, propofol, or pentobarbital on the day of the procedure. We characterized the distribution of infant characteristics and evaluated the relationship between drug administration and any adverse event. We performed propensity score matching, regression adjustment (RA), and inverse probability weighting (IPW) to ensure comparison of similar infants and to account for confounding by indication and residual bias. Results were assessed for robustness to analytical technique by reanalyzing the main outcomes with multivariate logistic regression, a doubly robust IPW with RA model, and a doubly robust augmented IPW model with bias-correction.

RESULTS

Of 650 infants, 497 (76%) received chloral hydrate, 79 (12%) received midazolam, 54 (8%) received lorazepam, and 15 (2%) received pentobarbital. Adverse events occurred in 41 (6%) infants. Using propensity score matching, chloral hydrate was associated with a decreased risk of an adverse event compared to other sedatives, risk difference (95% confidence interval) of -12.79 (-18.61, -6.98), p <  0.001. All other statistical methods resulted in similar findings.

CONCLUSION

Administration of chloral hydrate to hospitalized infants undergoing minor procedures is associated with a lower risk for adverse events compared to other sedatives.

Continuous intravenous to oral morphine switch in very premature ventilated infants: A retrospective study on efficacy, efficiency, and tolerability

Background

Continuous intravenous (IV) morphine is commonly used in ventilated neonates. Oral route is theoretically feasible but data on oral morphine in ventilated premature infants are lacking.

Objective

To assess the efficacy, efficiency, and tolerability of a continuous intravenous to oral morphine switch protocol.

Design

Retrospective study.

Setting

Single level III center's neonatal intensive care unit.

Patients

Ventilated premature infants hospitalized in the NICU in 2016 and 2017, receiving continuous IV morphine with an expected ventilation course of at least 72 more hours. We excluded patients treated for withdrawal syndrome or palliative care.

Interventions

Continuous IV to oral morphine switch with the same initial cumulated daily dose.

Main outcome measures

Pain scores (ComfortNeo scale) and morphine doses were analyzed over time using Friedman's test in the 24 hours preceding and the 48 hours following the oral switch. Adverse effects attributable to opioids were collected.

Results

Seventeen infants were included with a median [IQR] gestational age at birth of 25.9 [24.6‐26.9] weeks and a median postnatal age at oral switch of 30 [22‐36] days. One patient's intravenous treatment had to be resumed because of a high ComfortNeo score. All others remained on oral morphine. No significant change over time was observed for ComfortNeo scores (P = .15). Median [IQR] doses were 13.5 [10‐20] µg/kg/h in the IV period and significantly increased to 15 [10‐25] µg/kg/h in the oral period (P = .009). No short‐term respiratory, digestive, or urinary adverse event was observed. After a median [IQR] duration of 13 [4‐20] days of oral morphine treatment, 11 (65%) patients showed signs of withdrawal. Upon hospital discharge, 16 infants (94%) had bronchopulmonary dysplasia and none had severe cerebral abnormality on brain imaging.

Conclusion

Oral morphine might be useful in ventilated neonates in the NICU but deserves further studies and additional safety assessment.

Managing neonatal pain in the era of non-invasive respiratory support

Non-invasive ventilation is currently the preferred respiratory support for premature infants with respiratory distress. The lung-protective effects of non-invasive ventilation should however not prompt disregard for the possible pain and discomfort it can generate. Non-pharmacological interventions should be used in all premature infants, regardless of their respiratory support, and are not detailed in this review. This review includes currently available evidence and gaps in knowledge regarding three aspects of pain management in premature infants receiving non-invasive ventilation: optimisation of non-invasive ventilation especially through the choice of positive pressure source, appropriate interface and synchronisation; sedative or analgesic drug use for strategies aiming at administering surfactant with reduction or avoidance of tracheal ventilation; risks and benefits of some analgesic and/or sedative drugs used to treat or prevent prolonged pain and discomfort during non-invasive ventilation. In spite of limited robust evidence, this overview should trigger caregivers' reflections on their daily practice.

Evidence-based clinical guidelines on analgesia and sedation in newborn infants undergoing assisted ventilation and endotracheal intubation

AIM

This review informed pain control guidelines for clinicians performing mechanical ventilation, nasal continuous positive airway pressure and endotracheal intubation on term and preterm newborn infants.

METHODS

We reviewed literature published between 1986 and June 2017 on analgesia and sedation during assisted ventilation and before endotracheal intubation in newborn infants admitted to neonatal intensive care units. The subsequent guidelines were developed using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Our review produced five strong standard of care recommendations. One, reduce neonatal stress and use nonpharmacological analgesia during invasive ventilation. Two, favour intermittent boluses of opioids, administered after pain scores and before invasive procedures, during short expected periods of mechanical ventilation, mainly in preterm infants affected by respiratory distress syndrome. Three, do not use morphine infusion in preterm infants under 27 gestational weeks. Four, always use algometric scores to titrate analgesic drugs doses. Five, use premedication before endotracheal intubation for a more rapid, less painful, less traumatic and safer manoeuvre. We also developed 30 conditional recommendations on therapeutic options.

CONCLUSION

Our review produced 35 recommendations on standard care and therapeutic options relating to the analgesia and sedation of newborn infants during ventilation and before endotracheal intubation.

Analgesic efficacy and safety of morphine in the Procedural Pain in Premature Infants (Poppi) study: randomised placebo-controlled trial

BACKGROUND

Infant pain has immediate and long-term effects but is undertreated because of a paucity of evidence-based analgesics. Although morphine is often used to sedate ventilated infants, its analgesic efficacy is unclear. We aimed to establish whether oral morphine could provide effective and safe analgesia in non-ventilated premature infants for acute procedural pain.

METHODS

In this single-centre masked trial, 31 infants at the John Radcliffe Hospital, Oxford, UK, were randomly allocated using a web-based facility with a minimisation algorithm to either 100 μg/kg oral morphine sulphate or placebo 1 h before a clinically required heel lance and retinopathy of prematurity screening examination, on the same occasion. Eligible infants were born prematurely at less than 32 weeks' gestation or with a birthweight lower than 1501 g and had a gestational age of 34-42 weeks at the time of the study. The co-primary outcome measures were the Premature Infant Pain Profile-Revised (PIPP-R) score after retinopathy of prematurity screening and the magnitude of noxious-evoked brain activity after heel lancing. Secondary outcome measures assessed physiological stability and safety. This trial is registered with the European Clinical Trials Database (number 2014-003237-25).

FINDINGS

Between Oct 30, 2016, and Nov 17, 2017, 15 infants were randomly allocated to morphine and 16 to placebo; one infant assigned placebo was withdrawn from the study before monitoring began. The predefined stopping boundary was crossed, and trial recruitment stopped because of profound respiratory adverse effects of morphine without suggestion of analgesic efficacy. None of the co-primary outcome measures differed significantly between groups. PIPP-R score after retinopathy of prematurity screening was mean 11·1 (SD 3·2) with morphine and 10·5 (3·4) with placebo (mean difference 0·5, 95% CI -2·0 to 3·0; p=0·66). Noxious-evoked brain activity after heel lancing was median 0·99 (IQR 0·40-1·56) with morphine and 0·75 (0·33-1·22) with placebo (median difference 0·25, 95% CI -0·16 to 0·80; p=0·25).

INTERPRETATION

Administration of oral morphine (100 μg/kg) to non-ventilated premature infants has the potential for harm without analgesic efficacy. We do not recommend oral morphine for retinopathy of prematurity screening and strongly advise caution if considering its use for other acute painful procedures in non-ventilated premature infants.

FUNDING

Wellcome Trust and National Institute for Health Research.

Does Topical Lidocaine Reduce the Pain Associated With the Insertion of Nasal Continuous Positive Airway Pressure Prongs in Preterm Infants?: A Randomized, Controlled Pilot Trial

OBJECTIVE

To evaluate the efficacy of topical lidocaine 2% gel in reducing the pain associated with the insertion of nasal continuous positive airway pressure (nCPAP) prongs in preterm infants.

MATERIALS AND METHODS

A pilot randomized controlled trial. Sixty preterm infants, categorized into lidocaine (n=30) and control groups (n=30). The primary outcome was Premature Infant Pain Profile (PIPP) score, secondary outcomes included salivary cortisol, presence of cry, the duration of first cry, and adverse effects of lidocaine.

RESULTS

There were no statistically significant differences between lidocaine and control groups regarding PIPP scores (mean±SD: 7.2±2.3 vs. 9.3±3.0, respectively, P=0.086). None of the infants in the lidocaine group had severe pain defined as a PIPP score>12, compared with 3 (10%) infants in the control group (P=0.056). Salivary cortisol concentrations were not significantly different between the lidocaine and control groups (mean±SD: 2.57±1.79 vs. 4.82±1.61 μg/dL, respectively, P=0.11). Standardized effect sizes for topical lidocaine were medium to large for reduction in PIPP scores and large for reduction in salivary cortisol (Cohen d=-0.78 and -1.32, respectively). No adverse effects were reported in infants receiving lidocaine.

DISCUSSION

Our data suggest that topical lidocaine did not reduce the pain associated with the insertion of nCPAP prongs in preterm infants. However, the trends for lower PIPP scores in the lidocaine group and the effect sizes for lidocaine on PIPP scores and salivary cortisol were large enough so that a large-scale randomized clinical trial is warranted to confirm or refute our results. Such a study should compare 2 or more active pain interventions during nCPAP application, rather than evaluating a single intervention versus placebo or no treatment.

Analgesic Efficacy of Oral Dextrose and Breast Milk during Nasopharyngeal Suctioning of Preterm Infants on CPAP: A Blinded Randomized Controlled Trial

Continuous positive airway pressure (CPAP) requires nasopharyngeal suctioning for airway patency, which is painful. Other procedures have used breast milk and 25% dextrose as analgesics. We aimed to compare their analgesic efficacy during nasopharyngeal suctioning in preterm neonates on CPAP. In this blinded randomized controlled trial, babies received 25% dextrose or breast milk orally. Pain before, during and after was assessed using the Premature Infant Pain Profile (PIPP) score. Analysis was done for 40 babies. The mean PIPP score in the 25% dextrose group during the procedure was 11.25 ± 2.73 and 13.2 ± 2.55 (p = 0.02) with the intervention and without. In the breast milk group the PIPP score during the procedure was 11.35 ± 3.05 and 13.45 ± 3.27 (p = 0.04); this difference persisted even after the procedure. There was no significant difference between the interventions. Both interventions significantly reduce pain. The analgesic effect of breast milk was sustained.

Assessment of pain during application of nasal-continuous positive airway pressure and heated, humidified high-flow nasal cannulae in preterm infants

OBJECTIVE

To assess pain and compare its severity in preterm infants during application of nasal-continuous positive airway pressure (nCPAP) and heated, humidified high-flow nasal cannulae (HHHFNC).

STUDY DESIGN

An observational cross-sectional study. Sixty preterm infants, categorized into nCPAP (n=37) and HHHFNC groups (n=23). Pain response was assessed using Premature Infant Pain Profile (PIPP), duration of first cry and salivary-cortisol concentrations.

RESULT

The PIPP scores were significantly higher in the nCPAP compared with HHHFNC group (10 (7-12) vs 4 (2-6), P<0.01). None of the infants in the HHHFNC group had severe pain defined as a PIPP score >12, compared with 5 (13.5%) infants in the nCPAP group. Salivary-cortisol concentrations were significantly higher in nCPAP group compared with the HHHFNC group (5.0 (3.6-5.9) vs 1.6 (1.0-2.3) nmol l(-1), P<0.01). A lower incidence of cry was observed for infants in the HHHFNC group compared with the nCPAP group (11 (47.8%) vs 30 (81.1%), P<0.001), however, the duration of first cry was not significantly different between groups. The respiratory rate was significantly lower after application of HHHFNC compared with nCPAP (P<0.001). There were no significant differences between groups with regard to fraction of inspired oxygen (FiO2), oxygen saturation by pulse oximeter (SpO2) and heart rate.

CONCLUSION

The application of HHHFNC in preterm infants is associated with less pain compared with nCPAP, as it is associated with less PIPP scores and lower salivary-cortisol concentrations.

Analgesic and sedative drugs in newborns requiring respiratory support

Infants receiving respiratory assistance may feel pain due to underlying disease or ventilation itself. Pain control during neonatal respiratory care reduces morbidity. This article summarizes the main scientific evidence about the use of drugs during ventilatory assistance, and provides some practical suggestions on pain management in neonates with respiratory support.