Hush, little baby: The role of C-tactile afferents in babywearing infants with neonatal opioid withdrawal

Social touch through infant holding, skin-to-skin contact, and infant carrying (babywearing) decreases infant distress and promotes secure attachment. Unknown is the extent to which these effects are the result of the activation of C-Tactile afferents (CTs), the constellation of nerve fibers associated with affective touch, primarily located in the head and trunk of the body. The purpose of the present study was to compare dynamic touch (CTs activated) to static touch (CTs less activated) during a babywearing procedure among infants experiencing Neonatal Opioid Withdrawal Syndrome (NOWS). NOWS is a spectrum of clinical symptoms, including elevated heart rate (HR), associated with withdrawal from intrauterine opioid exposure. We hypothesized that stroking an infant's head during babywearing would amplify the pleasurable effect of babywearing as measured by changes in infant HR. Twenty-nine infants in a Neonatal Intensive Care Unit (NICU) in the Southwestern USA were worn in an infant carrier starting at five days old (M = 5.4, SD = 2.6; 46.2 % White, 26.9 % Latinx, 11.5 % Native American) and physiological readings were conducted daily; heart rates of infants and caregivers were taken every 15-seconds for 5-minutes, before, during, and after babywearing (30 min per phase). Each day infants alternated (randomly) in a static touch (hands-free babywearing) or dynamic touch condition (stroking the top of the infants' head at a velocity of 3 cm/s while babywearing). On average, infants completed 3 dynamic and 3 static babywearing sessions. Hospital and research staff participated in babywearing when a parent was not available (31.0 % of infants were exclusively worn by volunteers, 27.6 % were exclusively worn by parents). We analyzed the data using Hierarchical Linear Models due to the 3-level nested design (N = 29 infants, N = 191 readings, N = 11,974 heart rates). Compared to baseline (infant calm/asleep and without contact), infant's HRs significantly declined during and after babywearing, controlling for pharmacological treatment. These effects were significantly stronger during the dynamic touch condition (reduction in HR of 11.17 bpm) compared to the static touch condition (reduction in HR of 3.74 bpm). These effects did not significantly vary by wearer (mother, father, volunteer). However, differences between the dynamic and static conditions were significantly stronger in earlier babywearing sessions, potentially indicating a learning effect. There was evidence for a calming effect among caregivers as well, particularly in the dynamic touch condition, when caregivers were engaged in active touch. Activation of CTs appears to be an important mechanism in the physiological benefits of babywearing and in the symbiotic role of caregiver-infant attachment.

An Amplitude-Integrated EEG Evaluation of Neonatal Opioid Withdrawal Syndrome

OBJECTIVE

Infants with neonatal opioid withdrawal syndrome (NOWS) have disrupted neurobehavior that requires hospitalization and treatment. This article aimed to evaluate electroencephalography (EEG) abnormalities using amplitude-integrated EEG (aEEG) in NOWS.

STUDY DESIGN

Eighteen term born infants with NOWS were recruited prospectively for an observational pilot study. aEEG monitoring was started within 24 hours of recruitment and twice weekly through discharge. aEEG data were analyzed for background and seizures. Severity of withdrawal was monitored using the modified Finnegan scoring (MFS) system.

RESULTS

Fifteen neonates had complete datasets. Thirteen (87%) had continuous aEEG background in all recordings. None had sleep-wake cyclicity (SWC) at initial recording. Brief seizures were noted in 9 of 15 (60%) infants. Lack of SWC was associated with higher MFS scores. At discharge, 8 of 15 (53%) had absent or emerging SWC.

CONCLUSION

aEEG abnormalities (absent SWC) are frequent and persist despite treatment at the time of discharge in the majority of patients with NOWS. Brief electrographic seizures are common. Neonates with persistent aEEG abnormalities at discharge warrant close follow-up.

KEY POINTS

· EEG abnormalities are common and persist after clinical signs resolve in patients with NOWS.. · Short subclinical seizures may be seen.. · aEEG may identify neonates who need follow-up..

Feeding Behaviors in Infants With Prenatal Opioid Exposure: An Integrative Review

BACKGROUND

Oral feeding is one of the most complex maturational skills of infancy. Difficulties with feeding require specialized attention, and if not well managed, may prolong the newborn's hospital length of stay. This is particularly true for prenatally opioid exposed (POE) infants. A paucity of literature exists characterizing feeding behaviors of POE infants, yet feeding problems are common.

PURPOSE

The purpose of this integrative review was to synthesize and critically analyze the evidence that characterizes feeding behaviors in full-term, POE infants.

METHODS/SEARCH STRATEGY

The electronic databases of CINAHL, PubMed, Scopus, and PsycINFO were used. Inclusion criteria were studies in English, conducted from 1970 to 2019, with participant samples consisting of infants with prenatal opioid exposure, born full-term, and between 38 and 40 weeks of gestation. Based on the inclusion criteria, our search yielded 557 articles. After further screening, only 4 studies met our full inclusion/exclusion criteria. These studies were analyzed for evidence of infant feeding behaviors, including characterization of problematic feeding behavior for POE infants.

FINDINGS/RESULTS

Our findings revealed inconsistencies in characterization of feeding behaviors among POE infants. A synthesis of the most common evidence-based behaviors was constructed. Infant feeding behaviors were identified and grouped into 2 major behavior domains: (1) typical feeding behavior and (2) problematic feeding behavior.

IMPLICATIONS FOR PRACTICE AND RESEARCH

Feeding behaviors related to sucking and behavioral states may be different in POE infants. Further examination of effective assessment methods and the categorization of infant feeding behaviors are warranted for use in the development of evidence-based, targeted intervention.

Association of a Simplified Finnegan Neonatal Abstinence Scoring Tool With the Need for Pharmacologic Treatment for Neonatal Abstinence Syndrome

IMPORTANCE

Observer-rated scales, such as the Finnegan Neonatal Abstinence Scoring Tool (FNAST), are used to quantify the severity of neonatal abstinence syndrome (NAS) and guide pharmacologic therapy. The FNAST, a comprehensive 21-item assessment tool, was developed for research and subsequently integrated into clinical practice; a simpler tool, designed to account for clinically meaningful outcomes, is urgently needed to standardize assessment.

OBJECTIVES

To identify FNAST items independently associated with the decision to use pharmacologic therapy and to simplify the FNAST while minimizing loss of information for the treatment decision.

DESIGN, SETTING, AND PARTICIPANTS

This multisite cohort study included 424 neonates with opioid exposure who had a gestational age of at least 36 weeks with follow-up from birth to hospital discharge in the derivation cohort and 109 neonates with opioid exposure from the Maternal Opioid Treatment: Human Experimental Research Study in the validation cohort. Neonates in the derivation cohort were included in a medical record review at the Universities of Louisville and Kentucky or in a randomized clinical trial and observational study conducted at Tufts University (2014-2018); the Maternal Opioid Treatment: Human Experimental Research was conducted from 2005 to 2008. Data analysis was conducted from May 2017 to August 2019.

EXPOSURES

Prenatal opioid exposure.

MAIN OUTCOMES AND MEASURES

All FNAST items were dichotomized as present or not present, and logistic regression was used to identify binary items independently associated with pharmacologic treatment. The final model was validated with an independent cohort of neonates with opioid exposure.

RESULTS

Among 424 neonates (gestational age, ≥36 weeks; 217 [51%] female infants), convulsions were not observed, and high-pitched cry and hyperactive Moro reflex had extremely different frequencies across cohorts. Therefore, these 3 FNAST items were removed from further analysis. The 2 tremor items were combined, and 8 of the remaining 17 items were independently associated with pharmacologic treatment, with an area under the curve of 0.86 (95% CI, 0.82-0.89) compared with 0.90 (95% CI, 0.87-0.94) for the 21-item FNAST. External validation of the 8 items resulted in an area under the curve of 0.86 (95% CI, 0.79-0.93). Thresholds of 4 and 5 on the simplified scale yielded the closest agreement with FNAST thresholds of 8 and 12 (weighted κ = 0.55; 95% CI, 0.48-0.61).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that 8 signs of NAS may be sufficient to assess whether a neonate meets criteria for pharmacologic therapy. A focus on these signs could simplify the FNAST tool and may enhance its clinical utility.

Interventions for the Treatment of Neonatal Abstinence Syndrome

The growing incidence of neonatal abstinence syndrome (NAS) among newborns is a public health crisis that is a sequela of the national opioid crisis. When fetuses are exposed to opioids in utero, whether through prescription pain medication, illicit substances, or supervised medication-assisted opioid treatment, neonates can experience withdrawal symptoms shortly after birth. Opioid withdrawal manifests with symptoms of central nervous system and autonomic nervous system dysfunction. Treatment of NAS begins with nonpharmacologic interventions, and if a neonate requires more intensive treatment, care will escalate to include pharmacologic treatments, including morphine, methadone, and buprenorphine. When pharmacologic therapy begins, nonpharmacologic intervention is not ceased; rather, the two are used in conjunction in an attempt to reduce the amount of medication required for successful treatment. Herein we review nonpharmacologic nursing interventions, discuss the most common pharmacologic treatments for NAS, and present practice implications for nurses who work with childbearing families.

History of postpartum depression as a contributor to the severity of NAS

Currently, there are no clinical tools available to accurately predict the severity of neonatal withdrawal. Studies of non-exposed neonates suggest that maternal depression and anxiety are predictive of negative short and long-term neonatal outcomes, but research is lacking in the addicted population. We studied of 109 pregnant women in medication-assisted treatment (MAT) and their neonates to determine if psychiatric conditions co-occurring with Substance Use Disorder (SUD) contributed to the severity of neonatal withdrawal. The need for pharmacological intervention, Finnegan scores, length of methadone treatment, and length of hospital stay were used to assess withdrawal severity. Categorical variables were analyzed in Stata14 using Chi Square and continuous variables were analyzed using Wilcoxon Rank Sum. Among the 110 neonates whose outcomes were reviewed, a maternal history of Postpartum Depression (PPD) was found to be correlated with increased severity of withdrawal. The neonates born to mothers with past diagnoses of PPD had more consecutive days of high Finnegan scores (95% confidence interval [CI], P = 0.003), longer length of treatment (95% CI, P = 0.006), and length of hospital stay (95% CI, P = 0.014). There was no apparent relationship between NAS severity and other psychiatric disorders. In a study of pregnant women with SUD and their neonates, we uncovered a relationship between the severity of NAS and maternal history of PPD. Our findings demonstrate that further research into these deleterious outcomes is warranted. Until then, we suggest collection of maternal history of PPD and careful screening for new cases in the SUD population.

Natural drugs, not so natural effects: Neonatal abstinence syndrome secondary to 'kratom'

BACKGROUND

Mitragyna speciosa, also known as kratom, is obtained from the coffee plant family 'Rubiaceae.' Kratom is available in the form of capsules, whole, processed and powdered leaves, and as liquids. Secondary to its 'natural herb' status and opioid effects, it is misconceived to be a safe alternative for the treatment of chronic pain. The use of kratom has increased by tenfold in the United States since 2010.

METHODS AND RESULTS

We report a term neonate who was born to a chronic kratom user and required treatment with opiates for neonatal drug withdrawal.

CONCLUSION

Physicians should be aware of these herbal supplements and its potential withdrawal effects in newborn which cannot be picked up by the standard toxicology screen.

Novel Withdrawal Symptoms of a Neonate Prenatally Exposed to a Fentanyl Analog

Neonatal abstinence syndrome (NAS) is a withdrawal syndrome observed in neonates exposed to drugs in utero, typically opioids, which is associated with symptoms affecting the central and autonomic nervous systems and the gastrointestinal system. West Virginia, particularly the southeastern region of the state, has remarkably higher rates of NAS than similar communities. Our facility is increasingly faced with complex cases of NAS caused by in utero exposure to multiple substances. We present a case report of a neonate born to a 25-year-old mother enrolled in a medication-assisted treatment program for substance use disorder who was noncompliant in prenatal care, using multiple substances throughout the pregnancy, including gabapentin and fentanyl. After birth, the neonate began to exhibit unusual withdrawal symptoms including arching, tongue thrusting, and irregular eye movements, which are typically associated with in utero gabapentin exposure. The parents denied consent to treat with gabapentin, the suggested management for these symptoms; thus, a treatment protocol for methadone and clonidine were followed. This case exemplifies the medical and social complexities involved in treating polysubstance exposure-associated NAS.

Neonatal and longer term management following substance misuse in pregnancy

Substance misuse in pregnancy is not a new problem, but although impaired foetal growth and the risk of developing neonatal abstinence syndrome are widely appreciated, relatively little attention has been paid to longer term consequences for the infant. Available evidence indicates that prenatal exposure to opioids and other drugs of misuse is detrimental to the developing foetal brain; consistent with this, poor in utero head growth, delayed infant visual maturation and impaired general neurodevelopmental progress independent of social confounders are increasingly being recognised. This review considers current evidence and discusses best practice in the neonatal management and follow-up of affected babies. More studies are required to explore alternatives to methadone maintenance in pregnancy and to define optimal treatment for neonatal abstinence syndrome. All infants born to drug-misusing mothers must be considered vulnerable, even if they have not required treatment for neonatal abstinence syndrome.

Neonatal neurobehavior effects following buprenorphine versus methadone exposure

AIM

To determine the effects of in utero exposure to methadone or buprenorphine on infant neurobehavior.

DESIGN

Three sites from the Maternal Opioid Treatment: Human Experimental Research (MOTHER) study, a double-blind, double-dummy, randomized clinical trial participated in this substudy.

SETTING

Medical Centers that provided comprehensive maternal care to opioid-dependent pregnant women in Baltimore, MD, Providence, RI and Vienna, Austria.

PARTICIPANTS

Thirty-nine full-term infants.

MEASUREMENTS

The Neonatal Intensive Care Unit (NICU) Network Neurobehavioral Scale (NNNS) was administered to a subgroup of infants on postpartum days 3, 5, 7, 10, 14-15 and 28-30.

FINDINGS

While neurobehavior improved for both medication conditions over time, infants exposed in utero to buprenorphine exhibited fewer stress-abstinence signs (P < 0.001), were less excitable (P < 0.001) and less over-aroused (P < 0.01), exhibited less hypertonia (P < 0.007), had better self-regulation (P < 0.04) and required less handling (P < 0.001) to maintain a quiet alert state relative to in utero methadone-exposed infants. Infants who were older when they began morphine treatment for withdrawal had higher self-regulation scores (P < 0.01), and demonstrated the least amount of excitability (P < 0.02) and hypertonia (P < 0.02) on average. Quality of movement was correlated negatively with peak NAS score (P < 0.01), number of days treated with morphine for NAS (P < 0.01) and total amount of morphine received (P < 0.03). Excitability scores were related positively to total morphine dose (P < 0.03).

CONCLUSION

While neurobehavior improves during the first month of postnatal life for in utero agonist medication-exposed neonates, buprenorphine exposure results in superior neurobehavioral scores and less severe withdrawal than does methadone exposure.

Infant pupillary response to methadone administration during treatment for neonatal abstinence syndrome: a feasibility study

BACKGROUND

Pupil diameter is a frequently assessed objective index of the pharmacodynamic effects of opioids in adults, but to our knowledge has never been examined in infants. Such a measure could improve assessment and treatment of neonates exposed to opioids in utero. The present study examined changes in pupil diameter after opioid administration in opioid-exposed infants who required pharmacological treatment for neonatal abstinence syndrome (NAS) to test the feasibility of using pupil diameter as a measure of opioid effects in these infants.

METHODS

Ten infants (2-7 days old) receiving methadone (0.4-0.5 mg every 12 h) for the treatment of NAS participated. A picture of one of each infant's eyes was taken under controlled illumination conditions with a standard digital camera just prior to dosing and 0-1, 2-4, 5-7, and 8-10h after dosing. The diameters of the pupil and iris were measured and relative pupil diameter (pupil diameter expressed as a percentage of iris diameter) was analyzed.

RESULTS

Mean (±SE) relative pupil diameter decreased significantly after dosing from 41±2% to 29±2%. After dosing, a significant increasing linear trend was observed over time, with values of 29±2%, 33±3%, 38±3%, and 41±3% at 0-1, 2-4, 5-7, and 8-10h after dosing.

CONCLUSIONS

Infant pupils respond to opioid administration in the same sensitive, orderly manner as is commonly observed in adults. Pupil diameter appears to be an objective, sensitive measure of neonatal response to opioids that may be a useful complement to, or perhaps at times a replacement for, observer-rated scale scores.

Confirmation of gestational exposure to alprazolam by analysis of biological matrices in a newborn with neonatal sepsis

BACKGROUND

Different biological matrices are suitable for drug testing in newborns presenting with an acute withdrawal syndrome.

CASE REPORT

The newborn of a mother reporting alprazolam use during pregnancy presented with respiratory distress and clinical features consistent with neonatal withdrawal syndrome or neonatal sepsis of vertical transmission. Alprazolam and its main metabolite (alpha-hydroxyalprazolam) were detected in cord serum, neonatal urine and also in neonatal hair, meconium and placenta, accounting for both acute and chronic exposure to this benzodiazepine during intrauterine life. At the same time, the clinical diagnosis of neonatal sepsis was confirmed by isolation of Streptococcus agalactiae from otic cultures. The infant received oxygen therapy and antibiotic treatment and recovered completely at the age of 11 days. Although no congenital anomalies or behavioral alterations were diagnosed during hospitalization, periodic follow-ups were requested to check for potential long-term effects of prenatal exposure to alprazolam.

Prospective randomised comparative study of the effect of buprenorphine, methadone and heroin on the course of pregnancy, birthweight of newborns, early postpartum adaptation and course of the neonatal abstinence syndrome (NAS) in women followed up in the outpatient department

OBJECTIVE

The aim of the study was to evaluate the effect of substitution therapy in heroin addicted pregnant women on the course of pregnancy, perinatal outcomes and course of the neonatal abstinence syndrome.

DESIGN OF THE STUDY

A five-year randomised prospective comparative study

METHODS

The study was carried out in the period of 2002-2007. The group of patients included 147 i.v. heroin-addicted pregnant women. All of them were outpatients of our Perinatal Care Unit. Their daily dose of heroin was approximately lg. Later, 30 women were disqualified from the study for breaking the randomised criteria engagement. The substitution therapy in women who agreed to undergo it, started during the I. trimester of pregnancy. Finally, 47 heroin, 32 methadone and 38 buprenorphine addicted women were enrolled in the study. Birthweight of newborns was compared with the national birthweight tables. Severity and duration of neonatal abstinence syndrome (NAS) were evaluated by Finnegan s score scale.

RESULTS

None of the women delivered before the end of 34th gestational week. We did not encounter any perinatal death or developmental defect. The lowest birthweight, the highest number of newborns with IUGR and the most numerous placental changes were found in the group of heroin-addicted women. The differences compared to the two groups receiving substitution therapy were statistically significant (p < 0.05). The severity and course of NAS were the most severe (p < 0.001) in newborns of women from the methadone group.

CONCLUSION

Comparison of the groups of outpatients is in many ways questionable because of the restricted possibility of the patients' control. The lifestyle of addicted women has the same impact as the drug use alone. This is probably the main reason for differences in some of the monitored parameters between individual groups. Based on our results we can state that substitution therapy provides pregnant women with the possibility of social stabilization and adequate prenatal care. substitution therapy decreases the street heroin consumption. Methadone notably protracts the newborn's abstinence syndrome. With regard to this fact, attention has been recently focused on substitution with buprenorphine that seems to be from this viewpoint a more considerate option.

Adverse neurodevelopmental outcome of infants exposed to opiate in-utero

In-utero drug exposure is associated with increased risks of perinatal morbidity and mortality, however longer term neurodevelopmental outcome of survivors is poorly described.

AIMS

The aims of this paper are: (1) to review the published literature which examines neurodevelopmental outcome in infants with Neonatal Abstinence Syndrome (NAS) and (2) to report developmental follow-up data from a case-control study of babies exposed to opiate in-utero.

METHODS

This study was conducted at Royal Prince Alfred Hospital in Sydney, NSW, through the multidisciplinary NAS service. Literature was reviewed after searching MEDLINE for relevant studies. Our own case-control study was conducted to examine neurodevelopmental outcome. A number of standardized neuropsychological tools were employed to assess these infants.

RESULTS

Results from previously published studies on outcome of infants with NAS were not reassuring as to reported 'normal development'. In our own case-control study, opiate-exposed infants were significantly more likely to have neurodevelopmental impairment compared to healthy control infants, when assessed at 18 months and 3 years of age.

CONCLUSIONS

Infants exposed to opiates in-utero are at increased risk of neurodevelopmental problems throughout early childhood.

TDM Grand Rounds: Neonatal Nicotine Withdrawal Syndrome in an Infant Prenatally and Postnatally Exposed to Heavy Cigarette Smoke

A heavy smoking, lactating mother delivered a baby that exhibited spontaneous tremors, fluctuations of muscular rigidity, and opisthotonus at 48 hours of life. Although the symptoms did not disappear within the following days, they could be controlled by swaddling or wrapping the baby in a blanket. The absence of any other etiology generated a suspicion of prenatal exposure to heavy tobacco smoke and potential neonatal nicotine withdrawal syndrome. This diagnosis was supported by extremely high concentration of hair nicotine and cotinine in the infant's hair and in different segments of maternal hair. The presence of non-negligible amounts of nicotine and cotinine in breast milk confirmed that the mother did not quit smoking after delivery, despite her reports. The breast-fed newborn continued to have 3 to 4 crises of spontaneous tremors and alternant muscular rigidity per day for a month. More studies are needed to establish neonatal nicotine withdrawal.

Citalopram Serum and Milk Levels in Mother and Infant During Lactation

We present a case of intensified therapeutic drug monitoring (TDM) of citalopram in mother and newborn infant after clinically observed selective serotonin reuptake inhibitor (SSRI)-associated symptoms 2 weeks until 2 months after delivery. The SSRI-associated symptoms observed in the infant (up to 3 weeks after delivery) were irregular breathing, sleep disorders, hypotonia, and hypertonia. We conclude that the SSRI-associated symptoms in the infant represent citalopram withdrawal effects rather than side effects caused by breastfeeding. This case illustrates the importance of a flexible TDM program and a multidisciplinary approach in a hospital setting to deal with cases of drug-associated adverse effects, such as SSRI withdrawal effects.

Paroxetine Toxicity in a Newborn After In Utero Exposure

There are several case reports and case series that have examined the acute effects of selective serotonin reuptake inhibitors (SSRIs) on the newborn. There is considerable controversy whether the reported symptoms represent withdrawal from the SSRI or toxicity caused by the SSRI. A case of an infant who was exposed to paroxetine during pregnancy is presented. This case supports the notion of serotonin toxicity and is believed to be the first report that substantiates clinical symptoms with serum levels of the offending SSRI.

Neonatal animal models of opiate withdrawal

The symptoms of opiate withdrawal in infants are defined as neonatal abstinence syndrome (NAS). NAS is a significant cause of morbidity in term and preterm infants. Factors, such as polysubstance abuse, inadequate prenatal care, nutritional deprivation, and the biology of the developing central nervous system contribute to the challenge of evaluating and treating opiate-induced alterations in the newborn. Although research on the effects of opiates in neonatal animal models is limited, the data from adult animal models have greatly contributed to understanding and treating opiate tolerance, addiction, and withdrawal in adult humans. Yet the limited neonatal data that are available indicate that the mechanisms involved in these processes in the newborn differ from those in adult animals, and that neonatal models of opiate withdrawal are needed to understand and develop effective treatment regimens for NAS. In this review, the behavioral and neurochemical evidence from the literature is presented and suggests that mechanisms responsible for opiate tolerance, dependence, and withdrawal differ between adult and neonatal models. Also reviewed are studies that have used neonatal rodent models, the authors' preliminary data based on the use of neonatal rat and mouse models of opiate withdrawal, and other neonatal models that have been proposed for the study of neonatal opiate withdrawal.

Opiate physical dependence and N-methyl-D-aspartate receptors

The present review focused the involvement of N-methyl-D-aspartate (NMDA) receptors in morphine physical dependence. The increased levels of extracellular glutamate, NMDA receptor zeta subunit (NR1) mRNA, NMDA receptor epsilon 1 subunit (NR2A) protein, phosphorylated Ca(2+)/calmodulin kinase II (p-CaMKII) protein, c-fos mRNA, c-Fos protein, are observed in the specific brain areas of mice and/or rats showing signs of naloxone-precipitated withdrawal. In preclinical and clinical studies, a variety of NMDA receptor antagonists and pretreatment with an antisense oligonucleotide of the NR1 have been reported to inhibit the development, expression and/or maintenance of opiate physical dependence. In contrast to data obtained in adult animals, NMDA receptor antagonists are neither effective in blocking the development of opiate dependence nor the expression of opiate withdrawal in neonatal rats. In the NMDA receptor-deficient mice, the NR2A knockout mice show the marked loss of typical withdrawal abstinence behaviors precipitated by naloxone. The rescue of NR2A protein by electroporation into the nucleus accumbens of NR2A knockout mice reverses the loss of abstinence behaviors. The activation of CaMKII and increased expression of c-Fos protein in the brain of animals with naloxone-precipitated withdrawal syndrome are prevented by NMDA receptor antagonists, whereas the increased levels of extracellular glutamate are not prevented by them. These findings indicate that glutamatergic neurotransmission at the NMDA receptor site contributes to the development, expression and maintenance of opiate dependence, and suggest that NMDA receptor antagonists may be a useful adjunct in the treatment of opiate dependence.

Myocardial ischemia as a result of severe benzodiazepine and opioid withdrawal

Long-term infusion of benzodiazepines and opioids is strongly associated with dependence and withdrawal syndromes. We report the first case of severe benzodiazepine and opioid withdrawal resulting in transient myocardial ischemia.

CASE REPORT

A 6-month-old female born at 25 weeks gestation with severe opioid and benzodiazepine dependence resulting from multiple operative procedures and chronic ventilatory support was receiving continuous intravenous infusion of fentanyl and midazolam after trials of enteral methadone and diazepam had been unsuccessful due to gastric intolerance. On postoperative day 5 following Nissen fundoplication and gastrostomy tube placement, she acutely developed tachycardia, hypertension, agitation, loose stools, and yawning. Attempts to provide boluses of benzodiazepines and opioids revealed a very sluggish port in her subclavian central venous catheter. Prompt replacement of the catheter occurred without complication. After resuming infusions and providing additional sedatives and opioids, the loose stools, yawning, and agitation resolved. However, the tachycardia persisted. A 12-lead ECG was notable for significant ST depression in anterior leads. Laboratory studies revealed significantly elevated cardiac enzymes. The patient was transfused with packed red blood cells to optimize oxygen-carrying capacity. Echocardiography demonstrated a small region of dyskinetic apical endocardium. Cardiac enzymes normalized within 48 h. The ECG and echocardiographic findings fully resolved after approximately 70 h.

DISCUSSION

We believe that the sluggish central venous catheter port limited delivery of the midazolam and fentanyl to our patient. The resultant tachycardia and hypertension limited diastolic filling of the coronary arteries, resulting in myocardial ischemia. As the withdrawal was treated, heart rate and blood pressure returned to baseline, myocardial perfusion normalized, and the ST depression and the cardiac enzyme values normalized. This report underscores the significant morbidity associated with withdrawal syndromes and the need to recognize withdrawal early and to treat it aggressively.

Neonatal abstinence syndrome in methadone-exposed infants is altered by level of prenatal tobacco exposure

Maternal tobacco consumption during pregnancy has been associated with lower birth weight infants, preterm births, intrauterine growth retardation, smaller head circumference and increase in morbidity, yet few studies have examined the role tobacco has on the opiate neonatal abstinence syndrome (NAS). This study examined the effect of prenatal tobacco exposure on NAS for infants born to mothers maintained on methadone during gestation. Twenty-nine pregnant women and their newborn infants participated in this study. Tobacco exposure was based on maternal self-report with 16 women reporting cigarette consumption of 10 or less per day and 13 reporting smoking 20 cigarettes or more a day. The onset, peak, and duration of NAS were examined. Results showed that infants born to mothers who reported smoking 20 or more cigarettes per day had significantly higher NAS peak scores of 9.8 versus 4.8, and took longer to peak (113.0 h versus 37.8 h), than light smokers of 10 or fewer cigarettes per day. We concluded that tobacco use in conjunction with methadone plays an important role in the timing and severity of NAS in prenatally exposed infants.

Behavioral responses of substance-exposed newborns: a retrospective study

This study assessed the behavior of infants whose mothers had a drug history by using the Neonatal Behavioral Assessment Scale. Data were collected via retrospective chart review (N = 103). Urine testing was only reported for 66 mothers during pregnancy and at birth. Infants performed within normally expected ranges for all items, except consolability and self-quieting. These findings support the use of NBAS in assessing newborn behavior because the information gained assists the parent in providing a supportive care giving environment that will not only help the infant recover but also enhance interaction between infant and parent.