Neonatal and pediatric stress responses to anesthesia and operation

Sedation, Analgesia, and Neuromuscular Blockade: An Assessment of Practices From 2009 to 2016 in a National Sample of 66,443 Pediatric Patients Cared for in the ICU

OBJECTIVES

To describe the pharmaceutical management of sedation, analgesia, and neuromuscular blockade medications administered to children in ICUs.

DESIGN

A retrospective analysis using data extracted from the national database Health Facts.

SETTING

One hundred sixty-one ICUs in the United States with pediatric admissions.

PATIENTS

Children in ICUs receiving medications from 2009 to 2016.

EXPOSURE/INTERVENTION

Frequency and duration of administration of sedation, analgesia, and neuromuscular blockade medications.

MEASUREMENTS AND MAIN RESULTS

Of 66,443 patients with a median age of 1.3 years (interquartile range, 0-14.5), 63.3% (n = 42,070) received nonopioid analgesic, opioid analgesic, sedative, and/or neuromuscular blockade medications consisting of 83 different agents. Opioid and nonopioid analgesics were dispensed to 58.4% (n = 38,776), of which nonopioid analgesics were prescribed to 67.4% (n = 26,149). Median duration of opioid analgesic administration was 32 hours (interquartile range, 7-92). Sedatives were dispensed to 39.8% (n = 26,441) for a median duration of 23 hours (interquartile range, 3-84), of which benzodiazepines were most common (73.4%; n = 19,426). Neuromuscular-blocking agents were dispensed to 17.3% (n = 11,517) for a median duration of 2 hours (interquartile range, 1-15). Younger age was associated with longer durations in all medication classes. A greater proportion of operative patients received these medication classes for a longer duration than nonoperative patients. A greater proportion of patients with musculoskeletal and hematologic/oncologic diseases received these medication classes.

CONCLUSIONS

Analgesic, sedative, and neuromuscular-blocking medications were prescribed to 63.3% of children in ICUs. The durations of opioid analgesic and sedative medication administration found in this study can be associated with known complications, including tolerance and withdrawal. Several medications dispensed to pediatric patients in this analysis are in conflict with Food and Drug Administration warnings, suggesting that there is potential risk in current sedation and analgesia practice that could be reduced with practice changes to improve efficacy and minimize risks.

To Bathe or Not to Bathe: The Neonatal Question

After delivery, newborns go through a series of physiologic changes in an effort to adapt to extrauterine life, with preterm newborns more likely to experience medical problems following this transition. Neonatal hypothermia, defined as a temperature <36.5 °C, is a major contributor to neonatal mortality and morbidity. Early bathing may be a contributing factor to hypothermia and interfere with the premature neonate's ability to safely adapt to an extrauterine environment. Skin physiology, the physiologic changes that result from bathing, the importance of maintaining vernix for temperature stability, and how policy change and education-based programs for developmentally supportive care will be discussed in an attempt to improve patient care outcomes for neonates in the NICU.

Improved outcomes in paediatric anaesthesia: contributing factors

PURPOSE

To discuss developments in paediatric anaesthesia and explore the factors which have contributed to improved anaesthetic-related patient outcomes.

METHODS

Narrative review of findings in the literature retrieved from MEDLINE/Pubmed and manual search.

RESULTS

Adverse perioperative outcomes related to anaesthesia have been extensively debated over the past few decades, with studies implicating factors such as major human error and equipment failure. Case series and event registries have enlightened physicians on sources of error and patient risk factors such as extremes of age, comorbidity and emergent circumstances. Anaesthetic-related deaths in children fell from 6.4 per 10,000 anaesthetics in the early 1950s to as low as 0.1 per 10,000 anaesthetics by the end of the century. Advances in anaesthetic agents, techniques, monitoring technologies and training programmes in paediatric anaesthesia play a vital role in driving this downward trend.

CONCLUSION

Despite substantial progress, there is still much room for improvement in areas such as adverse-event reporting, anaesthetic-related risk and late neurocognitive outcomes. Systematic reviews comparing paediatric patient outcomes after neuroaxial block versus general anaesthesia are currently unavailable. The future of paediatric anaesthesia will most likely be influenced by much-needed large prospective studies, which can provide further insight into patient safety and service delivery.

The effect of continuous morphine administration on maternal plasma oxytocin concentration and uterine contractions after open fetal surgery

OBJECTIVE

A major complication of open fetal surgery is prematurity. We propose that fetal and maternal stress/pain after surgery may affect the concentration of circulating oxytocin and the frequency of uterine contractions, thus increasing the risk of preterm delivery. The objective of this study was to test whether continuous morphine sulfate administration after open fetal surgery has an effect on maternal plasma oxytocin concentration and the frequency of uterine contractions.

METHODS

An established time-pregnant primate model for open fetal surgery was used. From the time of surgery until the end of the three-day study period, three animals received prophylactic antibiotics, a bolus of indomethacin, and a bolus of morphine sulfate (group I). Three other animals received the same prophylactic antibiotics and an i.v. bolus of indomethacin, as well as a continuous i.v. infusion of morphine sulfate throughout the entire study period (group II). Maternal blood samples were collected to determine oxytocin plasma concentrations. Oxytocin was measured by radioimmunoassay. Uterine activity was continuously recorded through an amniotic fluid catheter and quantified as number of contractions (10 mmHg increase from base line in intrauterine pressure) per hour (UCs/h).

RESULTS

The mean maternal plasma oxytocin concentration was higher (p < 0.01) and the number of uterine contractions more frequent (p < 0.05) in the group of animals with intermittent doses of morphine than in the group that received morphine continuously.

CONCLUSIONS

These data suggest that maternal plasma oxytocin concentration and uterine activity after open fetal surgery may be related to inadequate maternal/fetal analgesia/sedation.

Blood Glucose Control During Selective Arterial Stimulation and Venous Sampling for Localization of Focal Hyperinsulinism Lesions in Anesthetized Children

Surgical management of congenital hyperinsulinism is improved by accurate localization of small, focal dysregulated pancreatic lesions using the arterial stimulation and venous sampling (ASVS) test, which can demonstrate increased hepatic venous insulin concentrations after selective arterial injections of calcium. However, anesthesia-related increases in blood glucose can induce insulin secretion, making it difficult to interpret ASVS test data. In this retrospective study, we examined the effect of anesthetic interventions on blood glucose concentrations in 68 children undergoing ASVS testing. We considered only the glucose concentrations observed before calcium stimulation in the final analysis. The choice of drugs for induction (sevoflurane, propofol, or thiopentone), maintenance inhaled anesthetics (sevoflurane, desflurane, or isoflurane), and the use of caudal epidural bupivacaine were not associated with significant differences in the mean blood glucose concentration before ASVS. However, patients receiving remifentanil infusions had smaller mean glucose concentrations (80 +/- 18 versus 100 +/- 44 mg x dl(-1), P = 0.01). These concentrations were also significantly smaller if tracheal intubation was delayed for at least 10 min after induction while patients received inhaled anesthetics via a face mask along with remifentanil infusions (79 +/- 14 for delayed intubation versus 95 +/- 39 mg x dl(-1) for early intubation, respectively, P = 0.03). The percentage increase in glucose concentrations from preintubation values was significantly smaller in these subjects (3.7% +/- 21.9% for delayed intubation versus 31.7% +/- 60.4% for early intubation, P = 0.02). We conclude that the anesthetic management protocol for these patients should include the use of remifentanil infusions and the administration of inhaled anesthetics and remifentanil infusions for a minimum of 10 min to establish a deep plane of anesthesia before tracheal intubation.

Cueing Into Infant Pain

Unfortunately the history of pain management in infant care has included decades of inadequate analgesia for a wide range of medical procedures, including major surgery. This was justified in part on fear of drug and analgesic risks to the infant, as well as the commonly held belief that infants do not respond to, or remember, painful experiences. Today we understand that infant pain is encoded into observable manifestations through which an infant communicates behavioral and physiological changes such as altered vital signs, characteristic cries, and facial expressions. The purposes of this article are to (1) describe infants' physiological and behavioral responses to pain and its adverse effects, (2) review pharmacologic and nonpharmacologic infant pain management modalities and reliable pain assessment tools for use in clinical practice, and (3) educate healthcare professionals about the importance of assessment and management of infant pain.

Methodological considerations for the use of heart rate variability as a measure of pain reactivity in vulnerable infants

Measures of HR and HRV offer multiple indices of reactivity to painful events. These measures are particularly helpful in preterm and ill infants where distress signals are often nonspecific and ambiguous. HR is easy to acquire, and a variety of widely used techniques are available for processing it. In general, the neuroanatomic and neurophysiologic bases for pain perception are in place even in the most preterm infant and produce patterns of HR and HRV responses that are similar across multiple settings. Developmental and experiential factors related to preterm birth, however, may affect these HR responses. Furthermore, evaluation of ill infants in an NICU setting adds multiple contextual factors that potentially influence HR and HRV and alter their specificity as measures of pain. In some cases, it may appear that pain reactivity is reduced when, in fact, HR reactivity is only an expression of the biologic capacity to produce a response, not the presence of a response itself. The nature of the setting and the infant's health, developmental stage, and behavioral state all contribute to potentially altering HR responses to painful events in this setting. Thus, the methodology used and its application must be flexible. A variety of HRV analysis techniques may be needed to identify a variety of response patterns and mechanisms that influence pain reactivity. Furthermore, careful selection of HR epochs for stationarity, an understanding of the potential discordance between biologic and behavioral measures, the effects of medication, and an accounting for developmental differences that occur during a typical NICU course are all critical factors for investigators to be aware of. Understanding cardiovascular reactivity as a measure of response to painful events in vulnerable infants requires ongoing work.

Efficacy of continuous versus intermittent morphine administration after major surgery in 0-3-year-old infants; a double-blind randomized controlled trial

A randomized double-blind clinical trial compared the efficacy of 10 microg/kg/h morphine continuous intravenous infusion (CM) with that of 30 microg/kg morphine (IM) every 3h after major abdominal or thoracic surgery, in 181 infants aged 0-3 years. Efficacy was assessed by the caregiving nurses with the COMFORT 'behavior' and a visual analogue scale (VAS) for pain, every 3h in the first 24h after surgery. Random regression modeling was used to simultaneously estimate the effect of randomized group assignment, actual morphine dose (protocol dosage plus extra morphine when required), age category, surgical stress, and the time-varying covariate mechanical ventilation on COMFORT 'behavior' and the observational VAS rated pain, respectively. Overall, no statistical differences were found between CM and IM morphine administration in reducing postoperative pain. A significant interaction effect of condition with age category showed that the CM assignment was favorable for the oldest age category (1-3 years old). The greatest differences in pain response and actual morphine dose were between neonates and infants aged 1-6 months, with lower pain response in neonates who were on average satisfied with the protocol dosage of 10 microg/kg/h. Surgical stress and mechanical ventilation were not related to postoperative pain or morphine doses, leaving the inter-individual differences in pain response and morphine requirement largely unexplained.

Hormonal and metabolic stress responses after major surgery in children aged 0-3 years: a double-blind, randomized trial comparing the effects of continuous versus intermittent morphine

Children aged 0-3 yr were stratified for age and randomized to receive either continuous morphine (CM, 10 microg x kg(-1) x h(-1)) with three-hourly placebo boluses or intermittent morphine (IM, 30 microg x kg(-1) every 3 h) with a placebo infusion for postoperative analgesia. Plasma concentrations of epinephrine, norepinephrine, insulin, glucose and lactate were measured before and at the end of surgery and 6, 12 and 24 h after surgery. Pain was assessed with validated pain scales [the COMFORT scale and a visual analogue scale (VAS)] with the availability of additional morphine doses. Minor differences occurred between the randomized treatment groups, the oldest IM group (aged 1-3 yr) having a higher blood glucose concentration (P=0.003), mean arterial pressure (P=0.02) and COMFORT score (P=0.02) than the CM group. In the neonates, preoperative plasma concentrations of norepinephrine (P=0.01) and lactate (P<0.001) were significantly higher, while the postoperative plasma concentrations of epinephrine were significantly lower (P<0.001) and plasma concentrations of insulin significantly higher (P<0.005) than in the older age groups. Postoperative pain scores (P<0.003) and morphine consumption (P<0.001) were significantly lower in the neonates than in the older age groups. Our results show that continuous infusion of morphine does not provide any major advantages over intermittent morphine boluses for postoperative analgesia in neonates and infants.

Cardiopulmonary bypass surgery does not further increase elevated serum leptin concentrations after major surgery

OBJECTIVE: The objective of the present study was to examine the impact of major heart surgery with cardiopulmonary bypass (CPB) in childhood on serum leptin concentrations in relation to plasma cortisol, epinephrine, norepinephrine, and insulin. DESIGN: Controlled, prospective study. SETTING: Intensive care unit of a university hospital. Patients and INTERVENTIONS: We enrolled 20 pediatric patients undergoing open heart surgery and 20 children with major surgery not necessitating CPB (surgical control group). Leptin was measured by radioimmunoassay, cortisol and insulin were measured by chemiluminescence, and epinephrine and norepinephrine were measured by high-pressure liquid chromatography. MEASUREMENTS AND MAIN RESULTS: In the CPB group, leptin dropped from 0.4 +/- 0.1 preoperatively (mean +/- sem) to 0.2 +/- 0.1 ng/mL intraoperatively (p <.05). It increased to 1.6 +/- 0.7 ng/mL 12 hrs after surgery (p <.01) and declined thereafter. In the surgical controls, leptin rose from 0.5 +/- 0.2 ng/mL before surgery to 1.8 +/- 0.8 ng/mL 12 hrs after surgery (p =.001). In both groups, plasma cortisol, insulin, and epinephrine significantly increased after surgery. There was no relationship between the maximum increase of serum leptin and the other hormones. CONCLUSIONS: Patients with CPB surgery and non-CPB surgery show a similar increase in serum leptin, indicating that sepsislike inflammatory syndrome does not further increase elevated leptin concentrations following major surgery. In this complex situation, serum leptin does not appear to be merely regulated by its known stimuli and suppressors.

Comparison of epidural morphine, hydromorphone and fentanyl for postoperative pain control in children undergoing orthopaedic surgery

The safety and side-effects profile of epidural administration of a hydrophilic (morphine), highly lipophilic (fentanyl) and a drug with intermediate hydrophilic and lipophilic activity (hydromorphone) were compared in 90 children undergoing orthopaedic procedures. Ninety patients were randomly assigned (30 in each group) to receive epidural morphine, hydromorphone, or fentanyl for postoperative analgesia. Respiratory effects, nausea, somnolence, urinary retention, pruritus and visual pain scales were evaluated and compared during a 30-h period following surgery. In the morphine group, 25% showed respiratory depression with oxygen saturation below 90% but there was no incidence of respiratory depression in the fentanyl or hydromorphone groups. Somnolence was prominent in some of the patients in all the groups, but was more prolonged in the morphine group. Statistically, there was no significant difference in nausea between the groups, but pruritus was more severe and frequent in the morphine group. The incidence of urinary retention in the morphine group was higher compared with the fentanyl and hydromorphone groups. In conclusion, epidural hydromorphone, demonstrating less side-effects, is preferable to morphine and fentanyl for epidural analgesia in children.

Extensor tendon lacerations in a preterm neonate

A fetus of 30-weeks' gestation sustained 2 extensor tendon lacerations as an intraoperative complication of an emergency Cesarean section. This report describes treatment of the tendon lacerations in the preterm neonate using 2 different repair techniques which both yielded an excellent clinical outcome.

Variation among neonatal intensive care units in narcotic administration

OBJECTIVES

To compare rates of narcotic administration for medically treated neonates in different neonatal intensive care units (NICUs) and to compare treated and untreated neonates to assess whether narcotics provided advantages or disadvantages for short-term outcomes, such as cardiovascular stability (ie, blood pressure and heart rate), hyperbilirubinemia, duration of respiratory support, growth, and the incidence of intraventricular hemorrhage.

STUDY DESIGN

The medical charts of neonates weighing less than 1500 g, admitted to 6 NICUs (A-F), were abstracted. Neonates who had a chest tube or who had undergone surgery were excluded from the study, leaving the records of 1171 neonates. We modeled outcomes by linear or logistic regression, controlling for birth weight (<750, 750-999, and 1000-1499 g) and illness severity (low, 0-9; medium, 10-19; high, > or =20) using the Score for Neonatal Acute Physiology (SNAP), and adjusted for NICU.

RESULTS

Narcotic use varied by birth weight (<750 g, 21%; 750-999 g, 13%; and 1000-1499 g, 8%), illness severity (low, 9%; medium, 19%; and high, 37%), day (1, 11%; 3, 6%; and 14, 2%), and NICU. We restricted analyses to the 1018 neonates who received mechanical ventilation on day 1. Logistic regression, adjusting for birth weight and SNAP, confirmed a 28.6-fold variation in narcotic administration (odds ratios, 4.1-28.6 vs NICU A). Several short-term outcomes also were associated with narcotic use, including more than 33 g of fluid retention on day 3 and a higher direct bilirubin level (6.8 micromol/L higher [0.4 mg/dL higher], P = .03). There were no differences in weight gain at 14 and 28 days or mechanical ventilatory support on days 14 and 28. Narcotic use was not associated with differences in worst blood pressure or heart rate or with increased length of hospital stay.

CONCLUSIONS

Our study found a 28.6-fold variation among NICUs in narcotic administration in very low-birth-weight neonates. We were unable to detect any major advantages or disadvantages of narcotic use. We did not assess iatrogenic abstinence syndrome or long-term outcomes. These results indicate the need for randomized trials to rationalize these widely differing practices.

The neuroanatomy, neurophysiology, and neurochemistry of pain, stress, and analgesia in newborns and children

Beginning with a brief description of mature anatomic pathways and neurotransmitters in the "pain system," this article details their development in the human fetus, neonate, and child. Special emphasis is given to the basic mechanisms and physiologic effects of opioid analgesia. The clinical implications of these data are described, particularly with regard to the maintenance of cardiovascular stability and hormonal-metabolic homeostasis in newborns and children undergoing surgery or other forms of stress.