Opioid tolerance in neonates: mechanisms, diagnosis, assessment, and management

Accuracy of diagnosing acute kidney injury by assessing urine output within the first week of life in extremely preterm infants

BACKGROUND

Neonatal acute kidney injury (AKI) is associated with increased mortality and is often assessed with the neonatal modified Kidney Disease: improving Global Outcomes (KDIGO) classification, which uses changes in serum creatinine levels. However, because this classification has many drawbacks, a novel method, the neonatal Risk, Injury, Failure, Loss, and End-Stage Kidney Disease (nRIFLE) classification for diagnosing neonatal AKI according to urine output (UO), was recently proposed. To date, no data on the incidence of AKI according to nRIFLE are available for extremely preterm infants (born at gestational age less than 28 weeks). This study was conducted to clarify the association between incidence of AKI and in-hospital mortality in extremely preterm infants.

METHODS

Of 171 extremely preterm infants hospitalized from 2006 to 2020, 84 in whom indwelling bladder catheters were placed for UO measurements within 24 h of life were included. The incidence of AKI was assessed using the nRIFLE classification. In-hospital mortality was compared between patients with AKI and those without it.

RESULTS

The incidence of AKI during the first week of life was 56% and that of in-hospital mortality was significantly higher in patients with AKI (25.5%) than in those without it (2.8%). The odds ratio was 12.3 with 95% confidence interval ranging from 1.5 to 100.0.

CONCLUSION

The incidence of AKI according to nRIFLE was higher than reported in most previous studies using the neonatal modified KDIGO classification, suggesting that assessment by nRIFLE criteria using UO may improve diagnostic accuracy of AKI in extremely preterm infants.

Study design and rationale for a randomized controlled trial to assess effectiveness of stochastic vibrotactile mattress stimulation versus standard non-oscillating crib mattress for treating hospitalized opioid-exposed newborns

The incidence of Neonatal Abstinence Syndrome (NAS) continues to rise and there remains a critical need to develop non-pharmacological interventions for managing opioid withdrawal in newborns. Objective physiologic markers of opioid withdrawal in the newborn remain elusive. Optimal treatment strategies for improving short-term clinical outcomes and promoting healthy neurobehavioral development have yet to be defined. This dual-site randomized controlled trial (NCT02801331) is designed to evaluate the therapeutic efficacy of stochastic vibrotactile stimulation (SVS) for reducing withdrawal symptoms, pharmacological treatment, and length of hospitalization, and for improving developmental outcomes in opioid-exposed neonates. Hospitalized newborns (n = 230) receiving standard clinical care for prenatal opioid exposure will be randomly assigned within 48-hours of birth to a crib with either: 1) Intervention (SVS) mattress: specially-constructed SVS crib mattress that delivers gentle vibrations (30-60 Hz, ~12 μm RMS surface displacement) at 3-hr intervals; or 2) Control mattress (treatment as usual; TAU): non-oscillating hospital-crib mattress. Infants will be studied throughout their hospitalization and post discharge to 14-months of age. The study will compare clinical measures (i.e., withdrawal scores, cumulative dose and duration of medications, velocity of weight gain) and characteristic progression of physiologic activity (i.e., limb movement, cardio-respiratory, temperature, blood-oxygenation) throughout hospitalization between opioid-exposed infants who receive SVS and those who receive TAU. Developmental outcomes (i.e., physical, social, emotional and cognitive) within the first year of life will be evaluated between the two study groups. Findings from this randomized controlled trial will determine whether SVS reduces in-hospital severity of NAS, improves physiologic function, and promotes healthy development.

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.

Vibrotactile stimulation: A non-pharmacological intervention for opioid-exposed newborns

Objective

To examine the therapeutic potential of stochastic vibrotactile stimulation (SVS) as a complementary non-pharmacological intervention for withdrawal in opioid-exposed newborns.

Study design

A prospective, within-subjects single-center study was conducted in 26 opioid-exposed newborns (>37 weeks; 16 male) hospitalized since birth and treated pharmacologically for Neonatal Abstinence Syndrome. A specially-constructed mattress delivered low-level SVS (30-60Hz, 10–12μm RMS), alternated in 30-min intervals between continuous vibration (ON) and no vibration (OFF) over a 6–8 hr session. Movement activity, heart rate, respiratory rate, axillary temperature and blood-oxygen saturation were calculated separately for ON and OFF.

Results

There was a 35% reduction in movement activity with SVS (p<0.001), with significantly fewer movement periods >30 sec duration for ON than OFF (p = 0.003). Incidents of tachypneic breaths and tachycardic heart beats were each significantly reduced with SVS, whereas incidents of eupneic breaths and eucardic heart beats each significantly increased with SVS (p<0.03). Infants maintained body temperature and arterial-blood oxygen level independent of stimulation condition.

Conclusions

SVS reduced hyperirritability and pathophysiological instabilities commonly observed in pharmacologically-managed opioid-exposed newborns. SVS may provide an effective complementary therapeutic intervention for improving autonomic function in newborns with Neonatal Abstinence Syndrome.

Neonatal pain management

Pain management in the neonatal ICU remains challenging for many clinicians and in many complex care circumstances. The authors review general pain management principles and address the use of pain scales, non-pharmacologic management, and various agents that may be useful in general neonatal practice, procedurally, or at the end of life. Chronic pain and neonatal abstinence are also noted.

Role of Clonidine in Neonatal Abstinence Syndrome

Objective: To provide a systematic review of the current role of clonidine in neonatal abstinence syndrome (NAS). Data Sources: A MEDLINE literature search inclusive of the dates 1946 to November 2015 was performed using the search terms clonidine and abstinence syndromes, neonatal. Excerpta Medica was searched from 1980 to November 2015 using the search terms clonidine and newborn. Additionally, Web of Science was searched using the terms clonidine and neon* inclusive of 1945 to November 2015. Study Selection and Data Extraction: We utilized the PRISMA guidelines to select English language, human primary literature, review articles, and supporting data assessing the efficacy of clonidine in the treatment of NAS. Data Synthesis: Three clinical trials and 5 observational studies demonstrated evidence of clonidine’s effectiveness in NAS. Clonidine’s therapeutic use as monotherapy and in combination with other agents was shown to reduce the time needed for pharmacotherapy treatment. Adverse reactions associated with clonidine in neonates, when reported, are mild. Conclusion: The American Academy of Pediatrics recommends opioids as first-line agents in the treatment of NAS when pharmacological treatment is indicated. Limited data suggest that clonidine, in combination with other agents or as monotherapy, may be as effective, with minimal adverse effects and reduced treatment time. Prospective clinical trials are necessary to clarify the ultimate role of clonidine in NAS and establish long-term safety.

Pain management in neonates

Multiple lines of evidence suggest an increased sensitivity to pain in neonates. Repeated and prolonged pain exposure may affect the subsequent development of pain systems, as well as potentially contribute to alterations in long-term development and behavior. Despite impressive gains in the knowledge of neonatal pain mechanisms and strategies to treat neonatal pain acquired during the last 15 years, a large gap still exists between routine clinical practice and research results. Accurate assessment of pain is crucial for effective pain management in neonates. Neonatal pain management should rely on current scientific evidence more than the attitudes and beliefs of care-givers. Parents should be informed of pain relief strategies and their participation in the health care plan to alleviate pain should be encouraged. The need for systemic analgesia for both moderate and severe pain, in conjunction with behavioral/environmental approaches to pain management, is emphasized. A main sources of pain in the neonate is procedural pain which should always be prevented and treated. Nonpharmacological approaches constitute important treatment options for managing procedural pain. Nonpharmacological interventions (environmental and preventive measures, non-nutritive sucking, sweet solutions, skin-skin contact, and breastfeeding analgesia) can reduce neonatal pain indirectly by reducing the total amount of noxious stimuli to which infants are exposed, and directly, by blocking nociceptive transduction or transmission or by activation of descending inhibitory pathways or by activating attention and arousal systems that modulate pain. Opioids are the mainstay of pharmacological pain treatment but there are other useful medications and techniques that may be used for pain relief. National guidelines are necessary to improve neonatal pain management at the institutional level, individual neonatal intensive care units need to develop specific practice guidelines regarding pain treatment to ensure that all staff are familiar with the effects of the drugs being used and to guarantee access and safe administration of pain treatment to all neonates.

Low-dose ketamine as a potential adjuvant therapy for painful vaso-occlusive crises in sickle cell disease

The hallmark of sickle cell disease (SCD) is the acute painful vaso-occlusive crisis (VOC). Among SCD patients, vaso-occlusive pain episodes vary in frequency and severity. Some patients rarely have painful crises, while others are admitted to the hospital multiple times in a year for parenteral analgesics. Opioids are the mainstay of therapy for SCD-related pain. However, a subset of patients report continued pain despite escalating doses of opioids. Tolerance and opioid-induced hyperalgesia (OIH) have been considered as possible explanations for this phenomenon. The activation of the N-methyl-d-aspartate (NMDA) receptor has been implicated in both tolerance and OIH. As a NMDA receptor agonist, ketamine has been shown to modulate opioid tolerance and OIH in animal models and clinical settings. Low-dose ketamine, by virtue of its NMDA receptor agonist activity, could be a useful adjuvant to opioid therapy in patients with refractory SCD-related pain. Based on limited studies of adjuvant ketamine use for pain management, low-dose ketamine continuous infusion appears safe. Further clinical investigations are warranted to fully support the use of low-dose ketamine infusion in patients with SCD-related pain.

Antioxidant enzyme and element status in heroin addiction or heroin withdrawal in rats: effect of melatonin and vitamin E plus Se

Heroin use, withdrawal syndrome, and heroin-related deaths are still the most serious public health problems. Antioxidants and bio-elements are essential for metabolism in living organisms. To our knowledge, there are no data about the effect of antioxidant therapy on the levels of bio-elements and antioxidant enzymes in the naloxone (NX)-induced heroin withdrawal syndrome. Therefore, in the present study for the first time, we have investigated the role of antioxidant therapy, melatonin, and vitamin E plus Se, on the trace and major elements and antioxidant enzymes in the heroin addiction or heroin withdrawal in rats. Glutathione peroxidase levels were increased and catalase levels were decreased in the all study groups when compared to the sham group. The level of superoxide dismutase (SOD) in the fixed dose of heroin (FDH) given group was lower; however, in the variable doses of heroin (VDH) given group SOD level was higher. Furthermore, in withdrawal syndrome, Fe, Mg, Mn, and Ti levels were diminished and Al, Ca, and Cu levels were increased in the FDH+NX group. Moreover, Mg, Mn, and Se levels were also diminished and Al level was increased in the VDH+NX group. In conclusion, our results obviously indicated that heroin effected both bio-element status and antioxidant enzyme activities and, exogenous melatonin or vE+Se therapy might relieve on the element and antioxidant enzyme the destructive activity caused by heroin.

Non-pharmacological techniques for pain management in neonates

Significant progress in understanding the physiology, clinical correlates, and consequences of neonatal pain have resulted in greater attention to pain management during neonatal intensive care. A number of nonpharmacological therapies have been investigated, including nonnutritive sucking, with and without sucrose use, swaddling or facilitated tucking, kangaroo care, music therapy, and multi-sensorial stimulation. Although the efficacy of these approaches is clearly evident, they cannot provide analgesia for moderate or severe pain in the neonate. Further, some of these therapies cannot be effectively applied to all populations of critically ill neonates. Acupuncture, an ancient practice in Chinese medicine, has gained increasing popularity for symptom control among adults and older children. Acupuncture may provide an effective nonpharmacological approach for the treatment of pain in neonates, even moderate or severe pain, and should be considered for inclusion in a graduated multidisciplinary algorithm for neonatal pain management.

Modeling the norketamine metabolite in children and the implications for analgesia

BACKGROUND

Norketamine, a metabolite of ketamine, is an analgesic with a potency one-third that of ketamine. The aim of this study was to describe norketamine pharmacokinetics in children in order to predict time-concentration profiles for this metabolite after racemic ketamine single dose and infusion administration. The possible analgesic potential resulting from norketamine concentration may then be predicted using simulation.

METHODS

Ketamine and norketamine data were available from two sources: (i) children presenting for procedural sedation in an emergency department given ketamine 1-1.5 mg.kg(-1) IV as a bolus dose; and (ii) a literature search of those studies describing ketamine and norketamine time-concentration profiles after either IV or IM single-dose ketamine in adults and children. A population pharmacokinetic analysis was undertaken using nonlinear mixed effects models (NONMEM). A two-compartment (central, peripheral) linear disposition model was used to fit the parent drug. An additional metabolite compartment was linked to the central compartment by series of intermediate compartments to account for norketamine delayed formation. Norketamine volume of distribution was fixed equivalent to central volume. Simulation was used to predict norketamine time-concentration profiles in children given either ketamine as an i.v. bolus 2 mg.kg(-1) or as an analgesic infusion 0.2 mg.kg(-1).h(-1) for 24 h.

RESULTS

The analysis comprised 621 observations from 70 subjects. There were 57 children (age 8.3, sd: 3.5 years, range: 1.5-14; weight 32.5, sd: 15.6 kg, range: 10.8-74.8) and 13 adults. Population parameter estimates for the parent drug, standardized to a 70 kg person using allometric models were central volume (V1) 22 (BSV 89.6%) l.70 kg(-1), peripheral volume of distribution (V2) 129 (30.9%) l.70 kg(-1), clearance other than that metabolized to norketamine (CLother) 47.8 (37.7%) l.h(-1).70 kg(-1) and intercompartment clearance (Q) 216 (54.5%) l.h(-1).70 kg(-1). The norketamine formation clearance (CL2M) was 12.4 (127%) l.h(-1).70 kg(-1), elimination clearance (CLM) was 13.5 (145%) l.h(-1).70 kg(-1), and the rate constant for intermediate compartments was 26.5 (59.1%) h(-1).

CONCLUSIONS

Ketamine has a longer elimination half-life (2.1 h) than norketamine (1.13 h). Simulation suggested that norketamine contributes to analgesia for 4 h after 2 mg.kg(-1) i.v. bolus, provided the assumption that a norketamine concentration above 0.1 mg.l(-1) contributes analgesia is true. Similarly, the norketamine metabolite may contribute to analgesia for 1.5 h after low-dose infusion (0.2 mg.kg(-1).h(-1)) cessation.

Chronic and cancer pain management

PURPOSE OF REVIEW

Chronic pain management in children is not recognized and treated adequately. The purpose of this review is to recognize some common chronic pain problems in children and offer guidelines for their management.

RECENT FINDINGS

This points to newer research in understanding complex regional pain syndromes-type 1 in children. This review will also discuss some recent findings regarding pain management techniques in children particularly the use of intravenous regional anesthesia for sympathetic blockade for complex regional pain syndromes-type 1. Cancer pain and headache with a logical step ladder management will be discussed.

SUMMARY

Although the under-treatment of chronic pain in children is still prevalent, it is important to understand the mechanisms and management of common pain problems in children and adolescents.

Withdrawal symptoms in children after long-term administration of sedatives and/or analgesics: a literature review. "Assessment remains troublesome"

BACKGROUND

Prolonged administration of benzodiazepines and/or opioids to children in a pediatric intensive care unit (PICU) may induce physiological dependence and withdrawal symptoms.

OBJECTIVE

We reviewed the literature for relevant contributions on the nature of these withdrawal symptoms and on availability of valid scoring systems to assess the extent of symptoms.

METHODS

The databases PubMed, CINAHL, and Psychinfo (1980-June 2006) were searched using relevant key terms.

RESULTS

Symptoms of benzodiazepine and opioid withdrawal can be classified in two groups: central nervous system effects and autonomic dysfunction. However, symptoms of the two types show a large overlap for benzodiazepine and opioid withdrawal. Symptoms of gastrointestinal dysfunction in the PICU population have been described for opioid withdrawal only. Six assessment tools for withdrawal symptoms are used in children. Four of these have been validated for neonates only. Two instruments are available to specifically determine withdrawal symptoms in the PICU: the Sedation Withdrawal Score (SWS) and the Opioid Benzodiazepine Withdrawal Scale (OBWS). The OBWS is the only available assessment tool with prospective validation; however, the sensitivity is low.

CONCLUSIONS

Withdrawal symptoms for benzodiazepines and opioids largely overlap. A sufficiently sensitive instrument for assessing withdrawal symptoms in PICU patients needs to be developed.

Sensorial Saturation for Neonatal Analgesia

AIM

Sensorial saturation (SS) is a procedure in which touch, massage, taste, voice, smell, and sight compete with pain, producing almost complete analgesia during heel prick in neonates. SS is an apparently complex maneuvre, but when correctly explained it is easily learnt. In the present paper, we studied its feasibility, assessing whether a long training is really needed to achieve good results.

MATERIALS AND METHODS

We enrolled 66 consecutive babies and divided them randomly into 3 groups which received the following forms of analgesia: glucose plus sucking (A), SS performed by nurses (B), SS performed by mothers (C). We did not use perfume on the caregivers' hands, so that babies could smell the natural scent of the hands. We assessed pain level by the ABC scale.

RESULTS

Median scores of groups A, B, and C were: 1 (0 to 6), 0 (0 to 4), and 0 (0 to 6), respectively. Mean scores were: 0.6, 0.6, and 1.7 and standard errors were 0.38, 0.22, and 0.32, respectively. Scores of groups B and C were significantly lower than that of A (P=0.03 and 0.006, respectively). No significant difference was found between values of scores of groups B and C.

CONCLUSIONS

Even without the use of perfume on the hands, SS was effective as an analgesic maneuvre. It made no difference whether SS was performed by mothers who applied it for the first time or experienced nurses. SS is rapid to learn and any caregiver (mother, pediatrician or nurse) can effectively use it.

Severe withdrawal syndrome in three newborns subjected to continuous opioid infusion and seizure activity dependent on brain hypoxia--ischemia. A possible link

BACKGROUND

The aim of this investigation was to verify whether brain hypoxia represented a risk factor for the occurrence and severity of opioid abstinence syndrome.

METHODS

Three newborns who manifested seizure activity as a result of hypoxia, focal brain ischemia, and hypoxia and sepsis, respectively, were compared with 17 neonates who suffered from hypoxia without developing seizure activity.

RESULTS

The first three neonates suffered a severe withdrawal syndrome (a rating on the neonatal abstinence score>17), the others did not.

CONCLUSIONS

It is hypothesized that brain hypoxia facilitated the occurrence and severity of the withdrawal syndrome because some key neurochemical processes (such as N-methyl-D-aspartate activation, protein kinase C activation and nitric oxide production) are common to both phenomena.

Role of endothelin (ETA) receptors in neonatal morphine withdrawal

We have previously demonstrated role of central endothelin (ET) receptors in neonatal morphine tolerance. The present study was conducted to investigate involvement of central ET receptors in neonatal rat morphine withdrawal. The aim was to determine activation of G-proteins coupled to opioid and ET receptors by morphine and ET ligands in neonatal rat brains during morphine withdrawal. Pregnant female rats were rendered tolerant to morphine by chronic exposure to morphine pellets over 7 days. Withdrawal was induced on day 8 by removal of pellets. Rat pups were delivered by cesarean section 24 h after pellet removal. G-protein stimulation induced by morphine; ET-1; ETA receptor antagonist, BMS182874; and ETB receptor agonist, IRL1620, was determined in the brain of neonatal rats undergoing morphine withdrawal by [35S]GTPgammaS binding assay. Morphine-induced maximal stimulation of G-protein in morphine withdrawal group (83.60%) was significantly higher compared to placebo control group (66.81%). EC50 value for ET-1-induced G-protein stimulation during morphine withdrawal (170.60 nM) was higher than control (62.5 nM). BMS182874, did not stimulate GTP binding in control but significantly increased maximal stimulation of G-proteins in morphine withdrawal (86.07%, EC50 = 31.25 nM). IRL1620-induced stimulation of G-proteins was similar in control and morphine withdrawal. The present findings indicate involvement of central ETA receptors in neonatal morphine withdrawal.

Douleur du nouveau-né : traitement pharmacologique

Pain causes numerous physiological changes in neonates. All invasive procedures induce undesirable stress responses; theses responses can, however, be eliminated or reduced by a judicious use of analgesia. Even though a large number of analgesics and sedatives are currently available, most of them have not been studied in the neonate. At present, a precise understanding of the pharmacological mechanisms of analgesics is difficult because many interactions still remain unknown in the term and premature neonate. This article describes the main analgesics and sedative agents used in the neonate: morphine, fentanyl, sufentanil, alfentanil, nalbuphine, ketamine, midazolam, propofol, acetaminophen, and Emla cream. After a review of the literature regarding these drugs, some practical advices and suggestions for the treatment of procedure-induced pain, and background sedation/analgesia for ventilated neonates are given. It is also stated in this article that the best way to soothe pain in neonates is to combine non pharmacological and pharmacological strategies. At the national level, written guidelines should be prepared in order to improve pain management in the neonate.

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.

The pharmacological treatment of neonatal pain

Optimal analgesia remains a major challenge for all involved in the care of (critically) ill newborns. The rapid changes in liver metabolism involving maturation of liver enzymes and renal clearance of drugs render (extreme) very low birth weight infants different from newborns of later postconceptional age with regards to the use of opioids such as morphine and fentanyl. Acute and/or procedural pain has been investigated fairly recently in randomized controlled trials and there are now guidelines. The long-term effects of opioid use in this particular age group of vulnerable babies await further evaluation.

Pain, opioid tolerance and sensitisation to nociception in the neonate

Pain is commonplace in newborn infants. Opioid analgesics have become increasingly used to reduce different types of pain in neonates, including pain from surgery, medical procedures and chronic conditions. Adverse effects of opioids include respiratory depression, hypotension and tolerance. These adverse effects can be minimised by utilising specific administration techniques and constant monitoring. Recent studies have demonstrated that untreated pain can have long-term effects on infant pain behaviours months beyond the events, thus, opioid analgesics may have a beneficial role that extends beyond the immediate painful event(s).

Measurement of movement is an objective method to assist in assessment of opiate withdrawal in newborns

OBJECTIVE

To develop an objective and reliable method to assess drug withdrawal in newborns by quantitatively estimating the amount of movement rather than scoring individual withdrawal signs.

DESIGN

In this cross sectional study, a commercial portable motion detector with computer memory, similar to a wrist watch (the actigraph) was used to measure movement. The measurements were compared with a clinical decision based on the neonatal abstinence syndrome (NAS) score. Movement was analysed, using non-parametric tests, in three groups: a control group of 10 infants, 13 opiate exposed newborns not treated for NAS, and 30 newborns treated for NAS (17 before treatment, eight within 24 hours of treatment, five when stabilised).

RESULTS

There were significant differences in the median activity score, expressed as counts per minute (cpm), in the pretreatment group (124 cpm) compared with the control (42 cpm, p < 0.0001), non-treated (74 cpm, p = 0.001), and stabilised treatment (75 cpm, p = 0.007) groups. The accuracy of the actigraph in the identification of newborns requiring treatment from those who did not was high compared with the clinical scores; sensitivity 94%; specificity 85%; positive and negative predictive values 88% and 92% respectively.

CONCLUSIONS

The measure of movement is comparable to the clinical score in the identification of newborns who require treatment and in determining the severity of withdrawal. The clear advantage of this method is its objectivity, reliability, and efficiency as a simple, non-invasive, bedside measure. Further evaluation in a randomised, controlled trial would establish comparative benefits, potential harms, safety, and acceptability.

Managing sedation withdrawal in children who undergo prolonged PICU admission after discharge to the ward

Children who undergo a prolonged stay within the intensive care unit require adequate sedation and analgesia. During the recovery phase there will need to be a period of sedation withdrawal to prevent occurrence of an abstinence syndrome. We present a strategy developed within our hospital for managing this process which uses the resource of the Pain Service, along with guidelines to help prevent the development of withdrawal, and a plan for managing any signs of abstinence which occur.

Does in utero exposure to heavy maternal smoking induce nicotine withdrawal symptoms in neonates?

Maternal drug use during pregnancy is associated with fetal passive addiction and neonatal withdrawal syndrome. Cigarette smoking-highly prevalent during pregnancy-is associated with addiction and withdrawal syndrome in adults. We conducted a prospective, two-group parallel study on 17 consecutive newborns of heavy-smoking mothers and 16 newborns of nonsmoking, unexposed mothers (controls). Neurologic examinations were repeated at days 1, 2, and 5. Finnegan withdrawal score was assessed every 3 h during their first 4 d. Newborns of smoking mothers had significant levels of cotinine in the cord blood (85.8 +/- 3.4 ng/mL), whereas none of the controls had detectable levels. Similar findings were observed with urinary cotinine concentrations in the newborns (483.1 +/- 2.5 microg/g creatinine versus 43.6 +/- 1.5 microg/g creatinine; p = 0.0001). Neurologic scores were significantly lower in newborns of smokers than in control infants at days 1 (22.3 +/- 2.3 versus 26.5 +/- 1.1; p = 0.0001), 2 (22.4 +/- 3.3 versus 26.3 +/- 1.6; p = 0.0002), and 5 (24.3 +/- 2.1 versus 26.5 +/- 1.5; p = 0.002). Neurologic scores improved significantly from day 1 to 5 in newborns of smokers (p = 0.05), reaching values closer to control infants. Withdrawal scores were higher in newborns of smokers than in control infants at days 1 (4.5 +/- 1.1 versus 3.2 +/- 1.4; p = 0.05), 2 (4.7 +/- 1.7 versus 3.1 +/- 1.1; p = 0.002), and 4 (4.7 +/- 2.1 versus 2.9 +/- 1.4; p = 0.007). Significant correlations were observed between markers of nicotine exposure and neurologic-and withdrawal scores. We conclude that withdrawal symptoms occur in newborns exposed to heavy maternal smoking during pregnancy.

Frequency of Newborn Behaviours Associated with Neonatal Abstinence Syndrome: A Hospital-Based Study

OBJECTIVES

To determine the frequency of neonatal abstinence syndrome (NAS) among unselected term newborns, using newborn behaviour data only.

METHODS

This hospital-based prospective exploratory study used clinical observations of newborn behaviours, mothers' observations of their newborns, and newborn chart data to determine the prevalence of suspected and confirmed cases of NAS in a convenience sample of unselected term newborns "rooming in" with their mothers in a large central city acute-care referral hospital. Over a 4-month period, 824 out of 1008 newborns were observed at between 8 and 30 hours of life by specially trained nurse observers. Behaviours recorded and their weighting were adapted from the Neonatal Abstinence Scoring System (NASS) by Finnegan and Kaltenbach. Newborns with scores of 5 or greater and "suspect for NAS" were referred to their physicians for confirmation or refutation of the clinical findings. The prevalence of "suspect for NAS" and confirmed NAS, as well as of individual neonatal behaviours, was calculated.

RESULTS

Thirty-one (3.8%) of 824 term "rooming in" newborns were identified with findings suggestive of NAS. Four newborns were positively identified as having NAS and treated. The identification was confirmed by post hoc affirmation of maternal drug use. Individual behaviours occurring in 10% or more of newborns included excessive sneezing, nasal stuffiness, unsustained suck, tremor, and abnormal nipple latch.

CONCLUSIONS

Clinical observation of newborn behaviour may identify NAS. Further studies are recommended to correlate this methodology with laboratory findings, as are more in-depth maternal questionnaires concerning use of mood-altering substances. The prevalence of NAS is likely underestimated because of early hospital discharge. A coordinated system of early identification and infant-specific assessment and treatment, both in hospital and following discharge home, is advocated.

Opioid withdrawal in critically ill neonates

OBJECTIVE

To determine the occurrence of and risk factors for opioid withdrawal in critically ill neonates receiving continuous infusions of fentanyl.

DESIGN

A prospective interventional cohort study was conducted in a university hospital neonatal intensive care unit with 19 neonates who received a minimum of 24 hours of fentanyl by continuous infusion.

MEASUREMENTS

Fentanyl total dose, duration of infusion, and peak infusion rate were recorded. Patients were evaluated for withdrawal using the Neonatal Abstinence Scoring System of Finnegan. Patients with a score >/=8 were considered to have opioid withdrawal.

MAIN RESULTS

Withdrawal was observed in 10 (53%) of 19 neonates. The fentanyl total dose (median 525 vs. 168 micro g/kg, respectively; p = 0.03) and infusion duration (median 10 vs. 7 d, respectively; p = 0.04) were significantly greater in neonates with withdrawal compared to those without withdrawal. A fentanyl total dose >/=415 micro g/kg predicted withdrawal with 70% sensitivity and 78% specificity. A fentanyl infusion duration >/=8 days predicted withdrawal with 90% sensitivity and 67% specificity. The most frequent symptoms of withdrawal were sleeping <3 hours after feeding (81%) and increased muscle tone (55%). In all neonates with withdrawal, onset occurred within 24 hours of fentanyl discontinuation.

CONCLUSIONS

Opioid withdrawal occurs frequently in critically ill neonates who receive continuous infusions of fentanyl. Longer infusion duration and higher total dose were associated with withdrawal symptoms.

Evaluation of a sedation protocol for intubated critically ill children

The aim of this study was to conduct an evaluation of a sedation protocol that transfers some decision-making authority for analgesia and sedation, within clearly defined parameters, to nurses in a pediatric intensive care unit (PICU). The sedation protocol used in this study was appropriate for any age group. The clinical course of 10 patients admitted to the PICU during a 5-month interval who were on the sedation protocol during their stay was examined using retrospective chart review. Time intervals when patients were on the protocol were compared with clinically comparable time intervals, in terms of acuity, when the same patient received conventional management. Data were collected on the number of days a child was ventilated, the number of days in the PICU, the number of days hospitalized and severity of illness. Additionally, data were collected on the amounts of sedation and analgesia required and the incidence of under-sedation. Physician and nurse satisfaction with the sedation protocol was examined using a self-report survey. The findings of this study indicate that the delegation of decision-making authority for analgesia and sedation to PICU nurses can provide effective and timely management of patient comfort, without an increase in morbidity, in a manner that is more satisfying for physicians and nurses.

Opioid analgesia for infants in the neonatal intensive care unit

There is an ethical obligation to relieve the pain and suffering in newborn infants. Opioids have been demonstrated to blunt the physiologic effects of pain and may prevent some of the clinical consequences of unmanaged pain. There are sufficient data to recommend the clinical use of opioid analgesics for the treatment of pain in the neonate. Neonates exposed to opioid analgesics can experience adverse effects. Adverse effects can be minimized by the use of various drug administration techniques and close monitoring. Further research is needed to determine how to optimize their effects. Data on the long-term effects of neonatal opioid exposure are warranted.

Effect of multisensory stimulation on analgesia in term neonates: a randomized controlled trial

Many attempts have been made to obtain safe and effective analgesia in newborns. Oral glucose-water has been found to have analgesic properties in neonates. We investigated whether other sensory stimulation added to oral glucose provided more effective analgesia than oral glucose alone. In a randomized prospective double-blind trial, we studied 120 term newborns during heel prick. The babies were divided randomly into six groups of 20, and each group was treated with a different procedure during heel prick: A) control; B) 1 mL 33% oral glucose given 2 min before the heel prick; C) sucking; D) 1 mL 33% oral glucose plus sucking; E) multisensory stimulation including 1 mL 33% oral glucose (sensorial saturation); F) multisensory stimulation without oral glucose. Sensorial saturation consisted in massage, voice, eye contact, and perfume smelling during heel prick. Each heel prick was filmed and assigned a point score according to the Douleur Aiguë du Nouveau-né (DAN) neonatal acute pain scale. Camera recording began 30 s before the heel prick, so it was impossible for the scorers to distinguish procedure A (control) from B (glucose given 2 min before), C (sucking water) from D (sucking glucose), and E (multisensory stimulation and glucose) from F (multisensory stimulation and water) from the video. Procedure E (multisensory stimulation and glucose) was found to be the most effective procedure, and the analgesia was even more effective than that produced by procedure D (sucking glucose). We conclude that sensorial saturation is an effective analgesic technique that potentiates the analgesic effect of oral sugar. It can be used for minor painful procedures on newborns.

Assessment and management of pain in neonates

Neonates are capable of experiencing pain from birth onwards. An impressive body of neuroanatomical, neurochemical and biobehavioural evidence, which has accumulated over the past 2 decades, supports this capability. This evidence mandates health professionals to attend to the prevention, elimination, or at the very least, control of pain for infants. This mandate is essential since pain is known to have both immediate and long term effects, especially if pain is untreated and is severe, prolonged or frequently experienced. Therefore, pain must be assessed frequently, not only to measure location, intensity and duration but also to determine the effectiveness of interventions implemented to control pain. An impressive array of measures for assessing acute pain in infants exists which incorporates valid pain indicators in this population. However, there is a need to develop new measures to assess chronic pain conditions and pain in infants in acute situations.

Pain management in the critically ill child

Children frequently received no treatment, or inadequate treatment, for pain and for painful procedures. The newborn and critically ill children are especially vulnerable to no treatment or under-treatment. Nerve pathways essential for the transmission and perception of pain are present and functioning by 24 weeks of gestation. The failure to provide analgesia for pain results in rewiring the nerve pathways responsible for pain transmission in the dorsal horn of the spinal cord and results in increased pain perception for future painful results. Many children would withdraw or deny their pain in an attempt to avoid yet another terrifying and painful experiences, such as the intramuscular injections. Societal fears of opioid addiction and lack of advocacy are also causal factors in the under-treatment of pediatric pain. False beliefs about addictions and proper use of acetaminophen and other analgesics resulted in the failure to provide analgesia to children. All children even the newborn and critically ill require analgesia for pain and painful procedures. Unbelieved pain interferes with sleep, leads to fatigue and a sense of helplessness, and may result in increased morbidity or mortality.

Prominence of withdrawal symptoms in polydrug-exposed infants

The problem of licit and illicit drug use during pregnancy continues to be a major perinatal health issue in this country. It is estimated that 200,000 infants are born each year to women who used illegal drugs while they are pregnant. Much information is available regarding the physiologic and neurobehavioral signs and symptoms of withdrawal expressed in infants exposed in utero to individual substances such as heroin, marijuana, methadone, alcohol, barbiturates, and PCP. However, little information is available related to the signs and symptoms of withdrawal observed in infants exposed to many combinations of these drugs prenatally. Additionally, few reports discuss the most prominent signs and symptoms of withdrawal in infants exposed to one or many drugs in utero. This article describes the results of a study that provides new information regarding the most prominent signs and symptoms of withdrawal exhibited by infants exposed to polydrugs, such as alcohol, opiates, stimulants, and sedatives, during pregnancy.