Effects of pain management on sleep in preterm infants

Background: This study was conducted to gain better understanding of the prolonged effects of pain and pain management on preterm infants’ sleep. Aim: The hypothesis was that the sleep structure in very preterm infants is different after painful procedures with pain management (facilitated tucking by parents (FTP), oral glucose, and oxycodone) than without pain management (oral water as placebo). Methods: A prospective randomized placebo‐controlled cross‐over trial design was used. Thirteen‐hour polysomnographic recordings were conducted when the study infants (n = 18) were at a post‐conceptional age of 28–32 weeks. During the recordings, the standardized nursing care periods were carried out with different forms of pain management administered at 3‐h intervals. Sleep structure was analyzed before and after the interventions. The main hypothesis was analyzed using mixed models. Results: During the first post‐intervention hour, the amount of rapid eye movement (REM) sleep decreased after all interventions regardless of pain management (p < 0.001). However, the oxycodone treatment further reduced the amount of REM sleep to 48.0% (SD 14.9) compared to other interventions: oral glucose to 64.4% (SD 12.8), (p < 0.001); placebo to 62.9% (SD 16.1), (p < 0.001); and FTP to 61.6% (SD 1.9), (p = 0.004). In addition, sleep onset comprised non‐rapid eye movement (NREM) sleep more frequently after oxycodone (50%) compared to placebo (6%, p = 0.006), oral glucose (11%, p = 0.019) or FTP (17%, p = 0.056). Conclusion: Pain management with oxycodone markedly altered the structure of the subsequent sleep period. This reduced amount of REM sleep may have consequences for brain development in preterm infants.     

剖宫产后早期皮肤接触促进足月儿母乳喂养的Meta分析

目的评价剖宫产术后早期皮肤接触护理在足月儿母乳喂养中的应用效果。方法检索中国知网(CNKI)、万方数据库、维普数据库、Cochrane Library、PubMed、Web of Science、EMBASE、EBSCO,检索时间均从建库至2019年3月。对纳入文献进行质量评价,并使用RevMan 5.3进行Meta分析。结果共纳入9篇文献,总样本量为1329例。Meta分析结果显示,剖宫产后早期皮肤接触护理组的足月儿首次母乳喂养时间早于常规护理组[MD=-28.86,95%CI(-32.16,-25.57),P<0.00001],母乳喂养评分高于常规护理组[MD=2.12,95%CI(0.89,3.35),P=0.0007],生后1个月[RR=1.14,95%CI(1.03,1.26),P=0.01]及生后6周~6个月[RR=1.20,95%CI(1.11,1.29),P<0.00001]的母乳喂养率均高于常规护理组。剖宫产后早期皮肤接触是一项安全有效的护理方式,不会对新生儿的体温产生不良影响[MD=0.09,95%CI(-0.11,0.28),P=0.39]。结论剖宫产术后早期实施皮肤接触护理是安全可行的,可改善母乳喂养情况,缩短首次母乳喂养时间,提高母乳喂养评分,提高生后1个月及6周~6个月的母乳喂养率。     

Evaluation of analgesic effect of skin-to-skin contact compared to oral glucose in preterm neonates

Nonpharmacological interventions are important alternatives for pain relief during minor procedures in preterm neonates. Skin-to-skin contact or kangaroo mother care is a human and efficient way of caring for low-weight preterm neonates. The aim of the present study was to assess the analgesic effect of kangaroo care compared to oral glucose on the response of healthy preterm neonates to a low-intensity acute painful stimulus. Ninety-five preterm neonates with a postmenstrual age of 28-36 weeks were randomly assigned to three groups in a single-blind manner. In group 1 (isolette, n=33), the neonate was in the prone position in the isolette during heel lancing and did not receive analgesia. In group 2 (kangaroo method, n=31), the neonate was held in skin-to-skin contact for 10 min before and during the heel-lancing procedure. In group 3 (glucose, n=31), the neonate was in the prone position in the isolette and received oral glucose (1 ml, 25%) 2 min before heel lancing. A smaller variation in heart rate (p=0.0001) and oxygen saturation (p=0.0012), a shorter duration of facial activity (brow bulge, eye squeeze and nasolabial furrowing) (p=0.0001), and a lower PIPP (Premature Infant Pain Profile) score (p=0.0001) were observed in group 2. In conclusion, skin-to-skin contact produced an analgesic effect in preterm newborns during heel lancing.     

早期母婴皮肤接触对新生儿体温和母乳喂养的影响

目的探讨早期母婴皮肤接触对新生儿体温和母乳喂养的影响。方法选取足月新生儿50例分为干预组(25例)和对照组(25例),对照组新生儿出生后接受常规产科护理,干预组新生儿在此基础上与母亲进行1 h的早期母婴皮肤接触,分别在新生儿出生后即刻、1 h、2 h、4 h测量腋窝温度;对两组新生儿首次母乳喂养和42 d母乳喂养情况进行评价。结果两组新生儿出生即刻的体温差异无统计学意义(P0.05);母婴皮肤接触1 h、2 h、4 h,干预组体温均高于对照组(P0.01)。干预组首次母乳喂养的成功率高于对照组(P0.01)。结论早期母婴皮肤接触可以提高新生儿体温,提高首次母乳喂养的成功率,值得在临床推广。     

Physiology of acute pain in preterm infants

Abstract Understanding the pain physiology of the preterm infant is essential to the provision of effective pain prevention and pain management. Peripheral and ascending pain pathways are mature by 20 weeks of gestation so infants are completely capable of feeling pain. The expression of pain in preterm infants is well documented. However, the immature descending pain pathway and lack of serotonin until 6 to 8 weeks after birth along with a greater density of pain receptors in the skin mean that preterm infants experience more severe pain than adults. The duration of the pain is longer, and the consequences of repeated painful procedures create permanent structural changes in the vulnerable nervous system of the preterm infant. Prevention of pain may preclude the permanent structural changes in the preterm nervous system, and adequate management when pain is necessary may prevent the psychologic and emotional consequences of repeated pain in the preterm infant. Copyright © 2001 by W.B. Saunders Company     

母婴皮肤接触持续时间对新生儿影响的研究

目的 评价新生儿出生后与母亲皮肤接触持续90 min对新生儿体温、安全感及母乳喂养的影响。方法 将在北京市3所医院分娩的320例正常产妇及正常足月新生儿随机分为两组：实验组新生儿出生后立即仰卧放置在产妇腹部,脐带搏动停止后断脐,新生儿俯卧于产妇胸前持续90 min后给予新生儿常规护理;对照组按常规方法断脐并给予常规护理操作后,将新生儿放置于产妇腹部进行母婴皮肤接触30 min。比较两组新生儿体温的变化情况,出生后90 min内啼哭次数,出现觅食反射的时间及早吸吮、早开奶的时间。结果 296例产妇及其新生儿完成研究,实验组150例,对照组146例。两组比较,实验组新生儿出生后 30 min、60 min、90 min、120 min体温均高于对照组,体温波动小于对照组,差异有统计学意义(P<0.001)。实验组新生儿出生后90 min内啼哭次数少于对照组、觅食反射出现时间早于对照组、第1次母乳喂养持续时间长于对照组,差异有统计学意义（P<0.001)。结论 母婴皮肤接触持续90 min有利于维持新生儿体温,增加新生儿安全感,促进母乳喂养。     

Repeatability of autonomic responses to pain anticipation and pain stimulation.

In this study we address the problem of the repeatability of autonomic responses in the experimental setting. In healthy volunteers, we measured the heart rate (HR) response to pain anticipation and to pain elicited with galvanic stimulation. After evaluation of pain threshold (T), all subjects underwent the same experimental protocol, whereby a painful stimulus at 1.5T was delivered on the forehead following a warning, while the ECG was continuously recorded. The procedure was repeated three times across a three-week period. The parameters recorded included pain threshold, pain rating, HR response to pain anticipation and HR response to pain. We found a high correlation among the three sessions for all parameters, indicating that, as occurs for pain threshold and pain rating, individual differences in autonomic responses can be reliably reproduced as well, even though significant habituation develops.     

Factors associated with vagal tone responses in preterm infants

The purpose of this study was to examine factors related to vagal tone (VNA) among preterm infants receiving a 10-minute gentle human touch (GHT) intervention three times daily for 10 days. VNA was measured continuously for 10 minutes before, during, and after each 10-minute GHT intervention. Findings indicated that there was a significant relationship between VNA and gestational age, although there were no relationships between VNA and measures of motor activity or behavioral distress. There was no difference in pattern of response to GHT or level of morbidity, average daily weight gain, or behavioral organization among infants with low, moderate, and high baseline VNA levels. There was no difference in VNA comparing infants in the GHT and control groups or during baseline, touch, and posttouch phases for infants in the GHT group. There is a need for further research to examine the usefulness of VNA as a measure of stress vulnerability among preterm infants.     

Randomized crossover trial of kangaroo care to reduce biobehavioral pain responses in preterm infants: a pilot study

Kangaroo care (KC), skin-to-skin contact between mother and infant, is a promising method for blunting pain responses. This crossover pilot tested KC effects on biobehavioral responses to heel stick in preterm infants (30-32 weeks' gestational age, 2-9 days old) measured by Premature Infant Pain Profile (PIPP) and salivary and serum cortisol. Mother-infant dyads were randomly assigned to KC heel stick (KCH) first or incubator heel stick (IH) first. Study 1 (80-min study, N = 18) tested the effect of 80 min of KC before and throughout the heel stick procedure versus incubator care. Study 2 (30-min study, N = 10) tested 30 min of KC before and throughout the heel stick versus incubator care. KCH and IH began during a premeasurement phase and continued through four data collection phases: baseline, heel warming, heel stick, and recovery. PIPP responses were measured every 30 s during data collection; salivary cortisol was measured at the end of baseline and recovery; and serum cortisol was measured during heel stick. Study 1 showed no differences between KCH and IH. Study 2 showed lower PIPP scores at four time points during recovery (p < .05 to p < .001), lower salivary cortisol at the end of recovery (p < .05), and lower serum cortisol during heel stick for the KCH condition (p < .05) as well as clinically lower PIPP scores in the KCH condition during heel stick. Thirty minutes of KC before and throughout the heel stick reduced biobehavioral responses to pain in preterm infants.     

Nurses' practices regarding procedural pain management of preterm infants

BackgroundIt is well known that preterm neonates can feel pain which can be expressed through specific behaviors and signs. Repeated and untreated pain has consequences for the preterm neonates such as hypersensitivity to pain, as well as important repercussions on their motor and intellectual development. The use of non-pharmacological interventions for pain management by nurses is imperative to prevent these consequences in the NICU. The aim of this study is to survey neonatal nurses' interventions for pain management of preterm neonates.MethodsTwenty (20) nurses were recruited for this pilot observational survey study. Standard pain management interventions used by nurses during heel prick were evaluated by means of a questionnaire. In addition, 11 out of the 20 nurses were observed during heel prick to evaluate what and how interventions were done.ResultsAll infants (n = 11) received at least one pain management intervention during heel prick. Heterogeneity in pain management practices used by nurses is considerable. For 95% (19/20) of nurses, sucrose is a standard intervention reported in the survey but observations showed that it not always applied (64%). Positioning is more used (64%) by nurses than reported in the survey (45%). Swaddling also was also reported as a standard intervention by 45% of nurses, but it does not appear to be adequately performed (36%).ConclusionAccording to the results, it would be essential to review nurses' knowledge and skills regarding standard pain management interventions, during painful procedures, as the quality of these practices is questionable. Homogeneity of the standard of care is particularly important in research to allow an appropriate comparison between study groups and prevention study bias.     

Effect of procedure light on the physiological responses of preterm infants

Aim:  Current recommendations for illumination in the NICU state that procedure light should be controlled with a rheostat to protect infants from high illumination. However, overhead fluorescent lights without a dimmer switch are still used in Japan. The aim of this study was to assess the effects of three different procedure lighting conditions (fluorescent with on/off switch rapidly increasing the level of light [FRL], incandescent with on/off switch rapidly increasing the level of light [IRL], and incandescent with dimmer switch slowly increasing the level of light [ISL]) on the respiratory rate (RR) and oxygen saturation (SpO₂) in preterm infants with or without oxygen therapy.
Methods:  Eight preterm infants, with a gestational age of 29–31 weeks, were included in a repeated randomized cross-over study. ANCOVAs, based on general linear mixed models, were used to examine physiological changes over time and across lighting conditions. In addition, the minimum SpO₂ values, after increasing the level of light, were classified into SpO₂ ≤ 85%, SpO₂ = 86–91%, and SpO₂ ≥ 92% for each lighting condition.
Results:  With and without oxygen therapy, the RR and SpO₂ under the ISL were higher than under the FRL and IRL. SpO₂ ≤ 85% was only observed under the FRL and SpO₂ = 86–91% was observed under the FRL and IRL.
Conclusions:  These data suggest that differences in the light conditions influence physiological responses in preterm infants and slowly increasing the level of light might make it easier for them to slowly adapt to high illumination and prevent declining SpO₂ values in neonates.     

Oral sucrose and pain relief for preterm infants.

The frequency of painful procedures performed on preterm infants in the neonatal intensive care unit (NICU) presents a challenge to nurses who are attempting to provide effective pain relief, and to the infants themselves who may suffer adverse consequences in response to repeated painful procedures. One new pain relief intervention under study is the administration of oral sucrose, which may activate endogenous opioid systems within the body. Studies with preterm infants that have examined the use of oral sucrose as an analgesic during heelsticks and venipunctures have shown that sucrose is effective in reducing pain. Sucrose may also be combined with nonnutritive sucking to provide significant pain relief. The use of oral sucrose is now recommended with a wide range of painful procedures in the NICU. Promising results have been observed in studies with both term and preterm infants, but less research has occurred with preterm infants. Additional research is warranted to determine the most effective approaches for the administration of sucrose, to examine the effectiveness of sucrose with additional types of painful procedures, and to examine the effects of long-term repeated use of sucrose.     

Pain-related emotions modulate experimental pain perception and autonomic responses

The effect of emotions on pain perception is generally recognized but the underlying mechanisms remain unclear. Here, emotions related to pain were induced in healthy volunteers using hypnosis, during 1-min immersions of the hand in painfully hot water. In Experiment 1, hypnotic suggestions were designed to induce various positive or negative emotions. Compared to a control condition with hypnotic-relaxation, negative emotions produced robust increases in pain. In Experiment 2, induction of pain-related anger and sadness were found to increase pain. Pain increases were associated with increases in self-rated desire for relief and decreases in expectation of relief, and with increases in arousal, negative affective valence and decreases in perceived control. In Experiment 3, hypnotic suggestions specifically designed to increase and decrease the desire for relief produced increases and decreases in pain, respectively. In all three experiments, emotion-induced changes in pain were most consistently found on ratings of pain unpleasantness compared to pain intensity. Changes in pain-evoked cardiac responses (R-R interval decrease), measured in experiments 2 and 3, were consistent with changes in pain unpleasantness. Correlation and multiple regression analyses suggest that negative emotions and desire for relief influence primarily pain affect and that pain-evoked autonomic responses are strongly associated with pain affect. These results confirm the hypothesized influence of the desire for relief on pain perception, and particularly on pain affect, and support the functional relation between pain affect and autonomic nociceptive responses. This study provides further experimental confirmation that pain-related emotions influence pain perception and pain-related physiological responses.     

早产儿皮肤接触护理临床效果的荟萃分析

目的 评价早产儿皮肤接触护理(skin-to-skin contact,sSC)的临床效果.方法 计算机检索相关文献,进行质量评价后按一定标准筛选文献,共纳入8篇随机对照试验,采用RevMan 4.2软件处理,从体温调节、呼吸和循环状况,母乳哏养,对探作性疼痛的缓解作用,精神运动功能发育,对母索情绪的影响6个方面进行Meta分析.结果 在体温调节、呼吸和循环状况方面,SSC组与常规护理组之间差异无显著性意义(P>0.05),在母乳喂养、对探作性瘁痛的缓解作用、精神运动功能发育、对母索情绪的影响方面差异有统计学意义(P<0.05).结论 Meta分析结果 表明SSC是一种科学、有效、人性化的新生儿护理模式,但文献间研究指标相差较大,无法进行合并处理,需要进行按照相同的纳入标准和研究指标的多中心研究,增加结果 的信度.     

Neonatal pain in relation to postnatal growth in infants born very preterm

Procedural pain is associated with poorer neurodevelopment in infants born very preterm (≤ 32 weeks gestational age), however, the etiology is unclear. Animal studies have demonstrated that early environmental stress leads to slower postnatal growth; however, it is unknown whether neonatal pain-related stress affects postnatal growth in infants born very preterm. The aim of this study was to examine whether greater neonatal pain (number of skin-breaking procedures adjusted for medical confounders) is related to decreased postnatal growth (weight and head circumference [HC] percentiles) early in life and at term-equivalent age in infants born very preterm. Participants were n=78 preterm infants born ≤ 32 weeks gestational age, followed prospectively since birth. Infants were weighed and HC measured at birth, early in life (median: 32 weeks [interquartile range 30.7-33.6]) and at term-equivalent age (40 weeks [interquartile range 38.6-42.6]). Weight and HC percentiles were computed from sex-specific British Columbia population-based data. Greater neonatal pain predicted lower body weight (Wald χ(2)=7.36, P=0.01) and HC (Wald χ(2)=4.36, P=0.04) percentiles at 32 weeks postconceptional age, after adjusting for birth weight percentile and postnatal risk factors of illness severity, duration of mechanical ventilation, infection, and morphine and corticosteroid exposure. However, later neonatal infection predicted lower weight percentile at term (Wald χ(2)=5.09, P=0.02). Infants born very preterm undergo repetitive procedural pain during a period of physiological immaturity that appears to impact postnatal growth, and may activate a downstream cascade of stress signaling that affects later growth in the neonatal intensive care unit.