Measuring the severity of surgical stress in newborn infants

Pathophysiology and Management of Postoperative Ileus in Adults and Neonates: A Review

Postoperative ileus (POI) is caused by enteric neural dysfunction and inflammatory response to the stress of surgery as well as the effect of anesthetics and opioid pain medications. POI results in prolonged hospital stays, increased medical costs, and diminished enteral nutrition, rendering it a problem worth tackling. Many cellular pathways are implicated in this disease process, creating numerous opportunities for targeted management strategies. There is a gap in the literature in studies exploring neonatal POI pathophysiology and treatment options. It is well known that neonatal immune and enteric nervous systems are immature, and this results in gut physiology which is distinct from adults. Neonates undergoing abdominal surgery face similar surgical stressors and exposure to medications that cause POI in adults. In this review, we aim to summarize the existing adult and neonatal literature on POI pathophysiology and management and explore applications in the neonatal population.

Biomarkers for assessing pain and pain relief in the neonatal intensive care unit

Newborns admitted to the neonatal intensive care unit (NICU) regularly undergo painful procedures and may face various painful conditions such as postoperative pain. Optimal management of pain in these vulnerable preterm and term born neonates is crucial to ensure their comfort and prevent negative consequences of neonatal pain. This entails accurate and timely identification of pain, non-pharmacological pain treatment and if needed administration of analgesic therapy, evaluation of treatment effectiveness, and monitoring of adverse effects. Despite the widely recognized importance of pain management, pain assessment in neonates has thus far proven to be a challenge. As self-report, the gold standard for pain assessment, is not possible in neonates, other methods are needed. Several observational pain scales have been developed, but these often rely on snapshot and largely subjective observations and may fail to capture pain in certain conditions. Incorporation of biomarkers alongside observational pain scores holds promise in enhancing pain assessment and, by extension, optimizing pain treatment and neonatal outcomes. This review explores the possibilities of integrating biomarkers in pain assessment in the NICU.

Trends in sedation-analgesia practices in pediatric liver transplant patients admitted postoperatively to the pediatric intensive care unit: An analysis of data from the pediatric health information system (PHIS) database

BACKGROUND

Children admitted to the pediatric intensive care unit (PICU), after liver transplantation, frequently require analgesia and sedation in the immediate postoperative period. Our objective was to assess trends and variations in sedation and analgesia used in this cohort.

METHODS

Multicenter retrospective cohort study using the Pediatric Health Information System from 2012 to 2022.

RESULTS

During the study period, 3963 patients with liver transplantation were admitted to the PICU from 32 US children's hospitals with a median age of 2 years [IQR: 0.00, 10.00]. 54 percent of patients received mechanical ventilation (MV). Compared with patients without MV, those with MV were more likely to receive morphine (57% vs 49%, p < .001), fentanyl (57% vs 44%), midazolam (45% vs 31%), lorazepam (39% vs. 24%), dexmedetomidine (38% vs 30%), and ketamine (25% vs 12%), all p < .001. Vasopressor usage was also higher in MV patients (22% vs. 35%, p < .001). During the study period, there was an increasing trend in the utilization of dexmedetomidine and ketamine, but the use of benzodiazepine decreased (p < .001).

CONCLUSION

About 50% of patients who undergo liver transplant are placed on MV in the PICU postoperatively and receive a greater amount of benzodiazepines in comparison with those without MV. The overall utilization of dexmedetomidine and ketamine was more frequent, whereas the administration of benzodiazepines was less during the study period. Pediatric intensivists have a distinctive opportunity to collaborate with the liver transplant team to develop comprehensive guidelines for sedation and analgesia, aimed at enhancing the quality of care provided to these patients.

Providing the Best Parenteral Nutrition before and after Surgery for NEC: Macro and Micronutrients Intakes

Necrotizing enterocolitis (NEC) is the main gastrointestinal emergency of preterm infants for whom bowel rest and parenteral nutrition (PN) is essential. Despite the improvements in neonatal care, the incidence of NEC remains high (11% in preterm newborns with a birth weight <1500 g) and up to 20−50% of cases still require surgery. In this narrative review, we report how to optimize PN in severe NEC requiring surgery. PN should begin as soon as possible in the acute phase: close fluid monitoring is advocated to maintain volemia, however fluid overload and electrolytes abnormalities should be prevented. Macronutrients intake (protein, glucose, and lipids) should be adequately guaranteed and is essential in each phase of the disease. Composite lipid emulsion should be the first choice to reduce the risk of parenteral nutrition associated liver disease (PNALD). Vitamin and trace elements deficiency or overload are frequent in long-term PN, therefore careful monitoring should be planned starting from the recovery phase to adjust their parenteral intake. Neonatologists must be aware of the role of nutrition especially in patients requiring long-term PN to sustain growth, limiting possible adverse effects and long-term deficiencies.

A Painful Beginning: Early Life Surgery Produces Long-Term Behavioral Disruption in the Rat

Early life surgery produces peripheral nociceptive activation, inflammation, and stress. Early life nociceptive input and inflammation have been shown to produce long-term processing changes that are not restricted to the dermatome of injury. Additionally stress has shown long-term effects on anxiety, depression, learning, and maladaptive behaviors including substance abuse disorder and we hypothesized that early life surgery would have long-term effects on theses complex behaviors in later life. In this study surgery in the rat hindpaw was performed to determine if there are long-term effects on anxiety, depression, audiovisual attention, and opioid reward behaviors. Male animals received paw incision surgery and anesthesia or anesthesia alone (sham) at postnatal day 6. At 10 weeks after surgery, open field center zone entries were decreased, a measure of anxiety (n = 20) (P = 0.03) (effect size, Cohen's d = 0.80). No difference was found in the tail suspension test as a measure of depression. At 16-20 weeks, attentional performance in an operant task was similar between groups at baseline and decreased with audiovisual distraction in both groups (P < 0.001) (effect size, η² = 0.25), but distraction revealed a persistent impairment in performance in the surgery group (n = 8) (P = 0.04) (effect size, η² = 0.13). Opioid reward was measured using heroin self-administration at 16-24 weeks. Heroin intake increased over time in both groups during 24-h free access (P < 0.001), but was greater in the surgery group (P = 0.045), with a significant interaction between time and treatment (P < 0.001) (effect size, Cohen f ² = 0.36). These results demonstrate long-term disruptions in complex behaviors from surgical incision under anesthesia. Future studies to explore sex differences in early life surgery and the attendant peripheral neuronal input, stress, and inflammation will be valuable to understand emerging learning deficits, anxiety, attentional dysfunction, and opioid reward and their mechanisms. This will be valuable to develop optimal approaches to mitigate the long-term effects of surgery in early life.

Factors affecting blood glucose and serum sodium level with intraoperative infusion of 1% dextrose in ringer's lactate in neonates undergoing surgery

Context:

Under anesthesia, blood glucose level in term neonates varies widely due to stress induced glucose mobilisation due to various factors. Postoperative hyponatremia occurs with intraoperative infusion of large volume of hypotonic fluid. There is a growing consensus on the intraoperative use of 1–4% glucose containing isotonic fluid in them.

Aims:

To know the relation of duration of surgery, infusion rate, fluid bolus, blood transfusion with blood glucose level and effect on serum sodium level with intraoperative 1% dextrose ringer's lactate (1% DRL) in neonates undergoing surgery.

Settings and Design:

Prospective single-center study in tertiary institute.

Subjects and Methods:

A total of 100 neonates undergoing various surgeries under general anesthesia with or without caudal anaesthesia were included. 1% DRL was used as maintenance and replacement fluid intraoperatively. Blood glucose level at hourly interval throughout surgery and serum sodium concentration before and after infusion was documented.

Statistical Analysis Used:

Student's t test (two tailed, independent) has been used for statistical analysis.

Results:

After the infusion of 1% DRL during surgery, mean blood sugar levels were increased above the base line in all neonates at successive hourly interval. Serum sodium levels remained within physiological range in all neonates.

Conclusion:

Intraoperative hyperglycemia is more obvious with higher intravenous fluid infusion rate, prolonged duration of surgery, and requirement of fluid bolus as well as blood transfusion intraoperatively. Use of 1% DRL in neonates undergoing surgery is effective in preventing dysnatremia.

A Pilot Study on Neonatal Surgical Mortality: A Multivariable Analysis of Predictors of Mortality in a Resource-Limited Setting

Purpose:

The aim of this research is to study the predictors of neonatal surgical mortality (NSM)-defined as in-hospital death or death within 30 days of neonatal surgery.

Materials and Methods:

All neonates operated over the study period of 18 months were included to evaluate NSM. The evaluated preoperative and intraoperative variables were birth weight, gestation age, age at presentation, associated anomalies, site and duration of surgery, intraoperative blood loss, and temperature after surgery. Assessed postoperative variables included the need for vasopressors, postoperative ventilation, sepsis, reoperations, and time taken to achieve full enteral nutrition. Univariate and multivariate logistic regression was applied to find the predictors of mortality.

Results:

Based on patient's final outcome, patients were divided into two groups (Group 1-survival, n = 100 and Group 2-mortality, n = 50). Incidence of NSM in this series was 33.33%. Factors identified as predictors of NSM were duration of surgery >120 min (P = 0.007, odds ratio [OR]: 9.76), need for prolonged ventilation (P = 0.037, OR: 5.77), requirement of high dose of vasopressors (P = 0.003, OR: 25.65) and reoperations (P = 0.031, OR: 7.16 (1.20–42.81).

Conclusion:

NSM was largely dependent on intraoperative stress factors and postoperative care. Neonatal surgery has a negligible margin of error and warrants expertize to minimize the duration of surgery and complications requiring reoperations. Based on our observations, we suggest a risk stratification score for neonatal surgery.

Intravenous morphine versus intravenous paracetamol after cardiac surgery in neonates and infants: a study protocol for a randomized controlled trial

BACKGROUND

Morphine is worldwide the analgesic of first choice after cardiac surgery in children. Morphine has unwanted hemodynamic and respiratory side effects. Therefore, post-cardiac surgery patients may potentially benefit from a non-opioid drug for pain relief. A previous study has shown that intravenous (IV) paracetamol is effective and opioid-sparing in children after major non-cardiac surgery. The aim of the study is to test the hypothesis that intermittent IV paracetamol administration in children after cardiac surgery will result in a reduction of at least 30% of the cumulative morphine requirement.

METHODS

This is a prospective, multi-center, randomized controlled trial at four level-3 pediatric intensive care units (ICUs) in the Netherlands and Belgium. Children who are 0-36 months old will be randomly assigned to receive either intermittent IV paracetamol or continuous IV morphine up to 48 h post-operatively. Morphine will be available as rescue medication for both groups. Validated pain and sedation assessment tools will be used to monitor patients. The sample size (n = 208, 104 per arm) was calculated in order to detect a 30% reduction in morphine dose; two-sided significance level was 5% and power was 95%.

DISCUSSION

This study will focus on the reduction, or replacement, of morphine by IV paracetamol in children (0-36 months old) after cardiac surgery. The results of this study will form the basis of a new pain management algorithm and will be implemented at the participating ICUs, resulting in an evidence-based guideline on post-operative pain after cardiac surgery in infants who are 0-36 months old.

TRIAL REGISTRATION

Dutch Trial Registry ( www.trialregister.nl ): NTR5448 on September 1, 2015. Institutional review board approval (MEC2015-646), current protocol version: July 3, 2017.

Steroid use for refractory hypotension in congenital diaphragmatic hernia

PURPOSE

Guidelines for diagnosis and treatment of adrenal insufficiency (AI) in newborns with congenital diaphragmatic hernia (CDH) are poorly defined.

METHODS

From 2002 to 2016, 155 infants were treated for CDH at our institution. Patients with shock refractory to vasopressors (clinically diagnosed AI) were treated with hydrocortisone (HC). When available, random cortisol levels <10 μg/dL were considered low. Outcomes were compared between groups.

RESULTS

Hydrocortisone was used to treat AI in 34% (53/155) of patients. That subset of patients was demonstrably sicker, and mortality was expectedly higher for those treated with HC (37.7 vs. 17.6%, p = 0.0098). Of the subset of patients with random cortisol levels measured before initiation of HC, 67.7% (21/31) had low cortisol levels. No significant differences were seen in survival between the high and low groups, but mortality trended higher in patients with high cortisol levels that received HC. After multivariate analysis, duration of HC stress dose administration was associated with increased risk of mortality (OR 1.11, 95% CI 1.02-1.2, p = 0.021), and total duration of HC treatment was associated with increased risk of sepsis (OR 1.04, 95% CI 1.005-1.075, p = 0.026).

CONCLUSION

AI is prevalent amongst patients with CDH, but prolonged treatment with HC may increase risk of mortality and sepsis.

Neurobiological Consequences of Early Painful Experience: Basic Science Findings and Implications for Evidence-Based Practice

As healthcare teams have worked to improve infant survival rates, the management of painful events experienced by these hospitalized neonates has increased and yet pain management remains highly variable between healthcare institutions. At the same time, emerging evidence suggests that these early painful experiences may alter the trajectory of development for pain-processing pathways both peripherally and centrally. This concise review highlights findings from both the basic and clinical science literature supporting the hypothesis that early painful experiences can have long-lasting negative effects on biological, psychological, and socioemotional functions. Implications for pain management in neonates and considerations for evidence-based practice change are discussed.

A double-edged sword: volatile anesthetic effects on the neonatal brain

The use of volatile anesthetics, a group of general anesthetics, is an exceedingly common practice. These anesthetics may have neuroprotective effects. Over the last decade, anesthetic induced neurotoxicity in pediatric populations has gained a certain notoriety based on pre-clinical cell and animal studies demonstrating that general anesthetics may induce neurotoxicity, including neuroapoptosis, neurodegeneration, and long-term neurocognitive and behavioral deficits. With hundreds of millions of people having surgery under general anesthesia worldwide, and roughly six million children annually in the U.S. alone, the importance of clearly defining toxic or protective effects of general anesthetics cannot be overstated. Yet, with our expanding body of knowledge, we have come to learn that perhaps not all volatile anesthetics have the same pharmacological profiles; certain ones may have a more favorable neurotoxic profile and may actually exhibit neuroprotection in specific populations and situations. Thus far, very few clinical studies exist, and have not yet been convincing enough to alter our practice. This review will provide an update on current data regarding volatile anesthetic induced neurotoxicity and neuroprotection in neonatal and infant populations. In addition, this paper will discuss ongoing studies and the trajectory of further research over the coming years.

Current concepts in the surgical approach to necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most common surgical emergency occurring in neonatal intensive care unit (NICU) patients. Among patients with NEC, those that require surgery experience the poorest outcomes and highest mortality. Surgical intervention, while attempting to address the intestinal injury and ongoing mulitfactorial physiologic insults in NEC is associated with its own stresses that may compound the ongoing physiologic derangement. Surgery is thus reserved for those patients with clear indication for intervention such as pneumoperitoneum, confirmed stool or pus in the peritoneal cavity, or worsening clinical status. The purpose of this review is to briefly describe the physiologic stress induced by surgical intervention in the preterm, low birth weight patient with NEC and to provide a contemporary overview of available surgical management options for NEC. The optimal surgical plan employed is strongly influenced by clinical judgment and theoretical benefits in terms of minimizing physiologic stressors while providing temporary and/or definitive treatment in a timely fashion. While the choice of operation has not been shown to have a significant effect on any clinically important outcomes, ongoing investigations continue to study both short and long-term outcomes in patients with NEC.

Sedation and analgesia to facilitate mechanical ventilation

Regardless of age, health care professionals have a professional and ethical obligation to provide safe and effective analgesia to patients undergoing painful procedures. Historically, newborns, particularly premature and sick infants, have been undertreated for pain. Intubation of the trachea and mechanical ventilation are ubiquitous painful procedures in the neonatal intensive care unit that are poorly assessed and treated. The authors review the use of sedation and analgesia to facilitate endotracheal tube placement and mechanical ventilation. Controversies regarding possible adverse neurodevelopmental outcomes after sedative and anesthetic exposure and in the failure to treat pain is also discussed.

Low CD8 T cells in neonates and infants prior to surgery, and health-care-associated infections: prospective observational study

BACKGROUND

Major surgery suppresses the cell-mediated immune response in children and adults. Data on preoperative and postoperative T-cell counts in pediatric surgical patients and their relationship to health-care-associated infection (HAI) are not yet known.

METHODS

A prospective observational study was carried out in a level III multidisciplinary neonatal and pediatric intensive care unit. Before and after, and in the first 3 days after surgery, lymphocyte subsets in peripheral blood were measured in 28 neonates and infants on flow cytometry. HAI were classified according to CDC/NHSN criteria.

RESULTS

Six out of 28 neonates and infants (21.4%) developed HAI (group I-HAI), while 22 out of 28 (78.6%) remained infection free (group II-non-HAI). In group I with HAI, the preoperative median cytotoxic T-lymphocyte (CD8-T-cell) level was found to be below normal, and remained very low throughout the study period. In addition, the median and interquartile CD8 T-cell range (358 cells/μL; 304-424 cells/μL) were twice as low compared to group II without HAI (822 cells/μL; 522-933 cells/μL; P = 0.013). No differences were found between the two groups with regard to patient demographics and clinical data.

CONCLUSION

Neonates and infants who underwent a major surgical procedure and who had a very low preoperative CD8 T-cell level, developed HAI postoperatively.

Endocrinopathies in the cardiac ICU

The past several years have seen an increased appreciation of the potential role of the endocrine system in the recovery process following surgery for congenital heart disease. Many of the hormonal changes following cardiac surgery are adaptive and necessary, whereas activation of proinflammatory cytokine and chemokine responses and some of the metabolic changes following surgery are likely mediators leading to detrimental outcomes. Additionally, other hormonal perturbations may contribute to adverse outcomes. This review examines the pain and the stress response, thyroid function and hyperglycemia following cardiopulmonary bypass (CPB), and the potential role of corticosteroids in the pediatric cardiac critical care unit.

Neonatal amygdala lesions alter basal cortisol levels in infant rhesus monkeys

The amygdala is mostly thought to exert an excitatory influence on the hypothalamic-pituitary-adrenal (HPA) axis, although its role regulating HPA basal tone is less clear, particularly during primate development. The current study examined the effects of neonatal amygdala lesions on basal HPA function and the postnatal testosterone (T) surge of rhesus monkeys reared with their mothers in large outdoor social groups. An early morning basal blood sample was collected at 2.5 months of age, whereas at 5 months samples were collected not only at sunrise, but also at mid-day and sunset to examine the diurnal rhythm of cortisol. At 2.5 months of age sham-operated males exhibited higher cortisol than females, but this sex difference was abolished by neonatal amygdalectomy, with lesioned males also showing lower basal cortisol than controls. Although neonatal amygdalectomy did not alter the postnatal T surge, there was a positive relationship between T and basal cortisol levels. At 5 months of age, neither the sex difference in cortisol, nor its correlation with T levels were apparent any longer. Instead, the diurnal cortisol rhythm of both males and females with amygdalectomy showed a blunted decline from mid-day to sunset compared to controls. These results indicate that neonatal amygdala damage alters basal HPA function in infant rhesus monkeys, affecting males only at early ages (at 2.5 months), while leaving the postnatal T surge intact, and resulting in a flattened diurnal rhythm in both genders at the later ages. Thus, the primate amygdala has a critical influence on the HPA axis in the first few months of life.

The making of a pediatric pain psychologist: education, training and career trajectories

Currently, there are no standard guidelines for the training of pediatric pain psychologists. This article is intended for pediatric pain medicine trainees and faculty in the USA and Canada, and includes discussion of the professional roles and responsibilities of pediatric pain psychologists, a historical perspective on the role of psychologists in the field of pediatric pain medicine, and career trajectories and recommendations for training of pediatric pain psychologists. The primary aim of this commentary is to provide a starting point for the standardization of training of pediatric pain psychologists in the future.

Clinical outcome of a randomized controlled blinded trial of open versus laparoscopic Nissen fundoplication in infants and children

OBJECTIVE

To compare the clinical outcome and endocrine response in children who were randomized to open or laparoscopic Nissen fundoplication using minimization.

BACKGROUND

It is assumed that laparoscopic surgery is associated with less pain, quicker recovery and dampened endocrine response. Few randomized studies have been performed in children.

METHODS

Parents gave informed consent, and this study was approved and registered (ClinicalTrials.gov Identifier: NCT00231543). Anesthesia, postoperative analgesia and feeding were standardized. Parents and staff were blinded to allocation. Blood was taken for markers of endocrine response.

RESULTS

Twenty open and 19 laparoscopic patients were comparable with respect to age, weight, neurological status, and presence of congenital anomalies. Median time to full feeds was 2 days in both groups (P = 0.85); hospital stay was 4.5 days in the open group versus 5.0 days in the laparoscopic group (P = 0.57). Pain was adequately managed in both groups and there was no difference in morphine requirements. Median follow-up was 22 (range 12-34) months. Dysphagia, recurrence and need for redo fundoplication were not different between groups; retching was higher after open surgery (56% vs. 6%; P = 0.003). Insulin levels decreased at 24 hours, and was 54% lower (P = 0.02) after laparoscopy. Cortisol was elevated immediately postoperative, but was 42% lower (P = 0.02) after laparoscopy.

CONCLUSIONS

There was no difference in the postoperative analgesia requirements and recovery. Laparoscopy decreased insulin levels to a greater extent, but caused less of a response in cortisol. Early postoperative outcome confirmed equal efficacy, but fewer children with retching after laparoscopy.

Safety of ketorolac in surgical neonates and infants 0 to 3 months old

BACKGROUND

Ketorolac is a nonsteroidal antiinflammatory drug widely used as an adjunct to postoperative pain control in adult and pediatric patients. Minimal safety data exist regarding the use of ketorolac in neonates.

METHODS

The charts of 57 postsurgical neonates between 0 and 3 months of age were retrospectively reviewed for bleeding events associated with ketorolac. Data included gestational age (GA), corrected gestational age (CGA) at the time of ketorolac, serum creatinine, platelet count, urine output (in milliliters per kilogram per hour), concomitant medications, enteral feeds, number of ketorolac doses, and surgical procedure performed.

RESULTS

Of 57 patients, 10 (17.2%) demonstrated a bleeding event. Mean CGA and serum creatinine for those with bleeding events was 39.4 weeks (P = .69) and 0.64 mg/dL (P = .03), respectively. Patients with a bleeding event received ketorolac at a mean of 20.7 days of life with 70% receiving the drug at less than 14 days of age, whereas those without a bleeding event received ketorolac at a mean of 31.9 days (P = .04). Bleeding events correlated with glomerular filtration rate of less than 30 mL/min/1.73 m(2) or concomitant medications in all but 1 patient.

CONCLUSIONS

Infants younger than 21 days and less than 37 weeks CGA are at significantly increased risk for bleeding events and should not be candidates for ketorolac therapy.

Total intravenous anesthesia (TIVA) in pediatric cardiac anesthesia

Although inhalational anesthesia with moderate- to high-dose opioid analgesia has been the mainstay of pediatric cardiac anesthesia, the availability of new short-acting drugs, new concepts in pharmacokinetic modeling and computer technology, and advances in surgery and perfusion have made total intravenous anesthesia (TIVA) an attractive option. In this article, we review some of the TIVA techniques used in pediatric cardiac anesthesia.

Does an objective system-based approach improve assessment of perioperative risk in children? A preliminary evaluation of the 'NARCO'

BACKGROUND

This study evaluated whether an objective tool would provide a more reliable and valid assessment of perioperative risk compared with the ASA-physical status (ASA-PS) in children.

METHODS

A system-based risk assessment tool was developed using these categories: Neurological, Airway, Respiratory, Cardiovascular, and Other (NARCO) with a subcomponent grading surgical severity (SS). Anaesthesiologists reviewed the preoperative assessments and assigned NARCO, SS, and ASA-PS scores independently. Perioperative outcomes were recorded by trained observers. Validity and reliability of the tools were evaluated.

RESULTS

NARCO correlated with ASA-PS (ρ=0.664; P<0.01) supporting its criterion validity. Inter-rater reliability of the measures was supported (intraclass correlation coefficients 0.71-0.96; κ 0.43-0.87) except for the Airway category. Measures of exact agreement were slightly better for NARCO compared with ASA-PS. NARCO, SS, and ASA-PS scores correlated significantly with perioperative escalation of care, adverse events (AE), hospital length of stay, and admission status. Correlations between NARCO and ASA-PS and outcomes improved when SS was factored into their coding. There were significant, but low, correlations between all measures and mortality. The odds of having escalation of care, AE, and mortality were 5-47 times greater among children with higher risk scores.

CONCLUSIONS

Findings suggest that all measures of outcome have acceptable to excellent reliability with a slight improvement in agreement for the NARCO compared with the ASA-PS. This study supports the validity of both the NARCO and the ASA-PS in predicting perioperative risk in children with a slight improvement in correlations when combined with the SS score.

The impact of the perioperative period on neurocognitive development, with a focus on pharmacological concerns

Mounting evidence from animal studies has implicated that all commonly used anaesthetics and sedatives may induce widespread neuronal cell death and result in long-term neurological abnormalities. These findings have led to serious questions regarding the safe use of these drugs in young children. In humans, recent findings from retrospective, epidemiological studies do not exclude the possibility of an association between surgery with anaesthesia early in life and subsequent learning abnormalities. These results have sparked discussions regarding the appropriate timing of paediatric surgery and the safe management of paediatric anaesthesia. However, important questions need to be addressed before findings from laboratory studies and retrospective clinical surveys can be used to guide clinical practice. This article summarises the currently available preclinical and clinical information regarding the impact of anaesthetics, sedatives, opioids, pain and stress, inflammation, hypoxia-ischaemia, co-morbidities and genetic predisposition on brain structure and long-term neurological function. Moreover, this article outlines the putative mechanisms of anaesthetic neurotoxicity, and the phenomenon's implications for clinical practice in this rapidly emerging field.

Adrenal function in newborns undergoing surgery

OBJECTIVE

To measure cortisol, adrenocorticotropic hormone (ACTH)-stimulated cortisol and ACTH values in the newborn intensive care unit-admitted newborn infants within 48 h before surgery and to describe the relationship of these values to measures of clinical illness before and after surgery.

STUDY DESIGN

In this prospective observational study, we measured baseline and ACTH-stimulated cortisol concentrations within 48 h before surgery in newborn infants <44 weeks postmenstrual age and examined the relationship of these values to measures of illness severity both before and after surgery, including the score for neonatal acute physiology (SNAP) and use of vasopressors. ACTH concentrations were measured in a subset of the infants.

RESULT

Twenty-five infants were enrolled and had median (25th to 75th percentile) baseline and ACTH-stimulated cortisol values of 7.1 (3.5 to 11.1) and 40.4 mcg per 100 ml (22.6 to 50.6). Preterm infants had significantly lower ACTH-stimulated cortisol values (median 21.6 vs 44.7 mcg per 100 ml). There was no correlation between any of these values and either the presurgical or postsurgical measures of illness severity, nor the increase in SNAP after surgery. Infants receiving vasopressors perioperatively had lower median ACTH-stimulated cortisol values (22.6 vs 44.7 mcg per 100 ml).

CONCLUSION

Presurgical cortisol values do not predict clinical response to surgical stress as measured by severity of illness scores but lower values were associated with vasopressor therapy. Further investigation would be required to determine how cortisol values are related to outcome and whether perioperative glucocorticoid supplementation would be beneficial in this population.

Remifentanil in neonatal intensive care and anaesthesia practice

Remifentanil is a relatively new ultrashort action synthetic opioid. Studies on the use of remifentanil in neonatology have emerged demonstrating its effectiveness and safety in neonates. The present study describes the use of remifentanil in both full-term and premature newborns, highlighting the theoretical benefits for this population in terms of both neonatal intensive care and anaesthesia. A Medline search was undertaken of all reviews and reports about the use of remifentanil in neonates published between 1996 and 2009 using MeSH search terms 'remifentanil', 'analgesia', 'anaesthesia', 'newborn' and 'neonate'. The review points that remifentanil has been used with advantages in newborns including preterm neonates and even for foetal anaesthesia. It proved to be a good option to attenuate the hemodynamic/endocrine markers of stress related to surgery. Owing to its unique pharmacokinetic profile, shorter extubation times can be achieved what makes the drug also a good option for short duration invasive procedures in NICUs (InSurE). A concern on its use is that the hemodynamic response (hypotension) may become significant when the drug is associated to other drugs like sevoflurane.

CONCLUSION

Remifentanil seems to be an effective and safely used opioid for neonatal intensive care and anaesthesia practice.

Relative adrenal insufficiency in the preterm and term infant

Cortisol release in the face of illness or stress is vital for survival. Relative adrenal insufficiency occurs when a patient's cortisol response is inadequate for the degree of illness or stress. Numerous studies have documented the existence of relative adrenal insufficiency in critically ill adults, and its association with increased morbidity and mortality. There is increasing evidence that relative adrenal insufficiency may be an etiology for hemodynamic instability and hypotension in the critically ill newborn, but compared with the adult population, there is still a paucity of data in this population. Randomized controlled trials are needed to evaluate the efficacy and safety of glucocorticoids for the treatment of cardiovascular insufficiency due to relative adrenal insufficiency in ill preterm and term newborn infants.

Prospective evaluation of the pharmacodynamics of piritramide in neonates and infants

Piritramide is a synthetic opioid commonly used in Germany and Austria for the analgesia of pediatric patients. Little pharmacokinetic and pharmacodynamic data for the pediatric population is available. The aim of this investigation was to gain pharmacodynamic data on postsurgical analgesia and the side effects of piritramide. The study was approved by the Ethics Committee of the Medical Faculty. Data were collected in an open, prospective clinical trial. After obtaining the parents' informed written consent, patients received a bolus of piritramide 50 mug/kg for postsurgical analgesia or to prevent pain resulting from invasive procedures. Titration doses of 15 microg/kg were allowed. Vital signs and pain intensity were closely monitored. Data from 39 patients could be included in the analysis. Of the patients, 95% were in the immediate postsurgical course, 5% had piritramide for invasive procedures, and 46% of the patients were ventilated. The mean piritramide dosage was 64 +/- 24 microg/kg. Pharmacodynamic analysis showed adequate analgesia for at least 50% of the spontaneously breathing patients for 120 min after piritramide bolus. More than 50% of the ventilated patients showed inadequate analgesia at any point in time after piritramide bolus. Fifty-nine percent (59%) of the ventilated patients received additive analgesia versus 31% of spontaneously breathing patients. No relevant changes of vital signs could be observed. One patient received naloxone for apnea. We conclude that dosages of more than 50-70 microg/kg are needed for sufficient analgesia in ventilated postsurgical infants. In spontaneously breathing patients, 50-70 microg/kg provides a 120-min period of analgesia for more than 50% of patients. Cardiovascular stability of the patients was good and, with one exception, there was no respiratory depression.

Anesthesia and analgesia during and after surgery in neonates

BACKGROUND

Historically, the use of anesthetics and analgesics in neonates and infants has been based on extrapolations from studies performed in adults and older children. Over the past 20 years, there has been a growing body of research on the clinical pharmacology and clinical outcomes of these agents in neonates and infants.

OBJECTIVE

This article summarizes clinical pharmacology and clinical outcomes studies of opioids, opioid antagonists, sedative-hypnotics, nonsteroidal anti-inflammatory drugs and acetaminophen, and local anesthetics in neonates and infants to highlight gaps in the available knowledge, review some concerns about study design, and identify drugs that should receive high priority for future study.

METHODS

Relevant studies were identified through a search of MEDLINE and a review of textbooks, conference proceedings, and abstracts. The available literature was subjected to expert committee-based review.

CONCLUSIONS

There is a growing body of information on analgesic and anesthetic pharmacokinetics, pharmacodynamics, and clinical outcomes in neonates and infants, permitting safe and effective use in some clinical settings. Major gaps in knowledge persist, however. Future research may involve a combination of clinical trials and preclinical studies in suitable infant animal surrogate models.

Anesthetics and brain toxicity

PURPOSE OF REVIEW

Recent experimental data from rodent studies have demonstrated accelerated neurodegeneration in rat pups exposed to commonly used anesthetic drugs. These provocative findings certainly question and undermine the safe use of anesthetic drugs, particularly in pediatric anesthesia, and have prompted many to investigate the neurotoxic effect of anesthetic drugs on the developing brain. This review will address the scientific evidence for the anesthetic-induced neurotoxicity and its applicability in humans.

RECENT FINDINGS

Several investigators have shown that prolonged administration of anesthetic drugs, including ketamine, isoflurane, nitrous oxide and midazolam, produced increased neurodegeneration in 7-day-old rat pups. The combination of the latter three drugs led to altered learning behavior in adulthood. Despite these unequivocal findings in rodents, similar changes cannot be reproduced in other species. Furthermore, withholding anesthesia during painful procedures in neonatal rats resulted in significant long-term aberrant responses to sensory stimulation and pain thresholds.

SUMMARY

Taken together, these studies question the applicability of these data to the anesthetic management of the neonate. Further investigations in this area are needed before withholding anesthetics in the anesthetic management of pediatric surgical patients.

Decreased monocyte class II MHC expression following major abdominal surgery in children is related to operative stress

Monocyte class II major histocompatibility complex (MHC) expression is necessary for antigen presentation and stimulation of T-cells. The aim of this study was to correlate monocyte class II MHC response to operative stress in children and the possible influence of cytokines in the postoperative period. We studied 21 children undergoing elective abdominal surgery. Operative stress score (OSS) was calculated. Monocyte class II MHC expression was measured preoperatively, immediately after surgery, 24 and 48 h postoperatively, using flow cytometry. Class II MHC is expressed as mean fluorescence intensity (MFI) of monocytes expressing MHC (mean +/- SD). Cytokine levels (interleukins 1ra, 6, and 10, and tumor necrosis factor-alpha) were also measured. Data between time points were compared using repeated measures ANOVA. There was an immediate postoperative decrease in class II MHC expression, with lowest levels 24 h postoperatively (preoperative 50 +/- 23.6, 24 h 18.2 +/- 9.4, P < 0.0001 vs. preoperative). At 48 h there was partial recovery in class II MHC, but levels were still significantly lower than preoperative (23.9 +/- 11.1, P < 0.001). The degree of monocyte depression was related to the magnitude of operative stress. Patients who had OSS <10 displayed some recovery in expression at 48 h 25.5 +/- 11.1), whereas in patients with OSS > or = 10 (severe surgical stress), expression further decreased at 48 h (MFI 14.0 +/- 0.1). There was an elevation of interleukin-1ra in the immediate postoperative period in both groups. There was no elevation in the other cytokines. Abdominal surgery in children decreases monocyte MHC expression. Class II MHC depression was related to magnitude of surgical trauma, implying that more severe immuneparesis follows surgery of greater magnitude. This may predispose to postoperative infection.

Summary proceedings from the neonatal pain-control group

Recent advances in neurobiology and clinical medicine have established that the fetus and newborn may experience acute, established, and chronic pain. They respond to such noxious stimuli by a series of complex biochemical, physiologic, and behavioral alterations. Studies have concluded that controlling pain experience is beneficial with respect to short-term and perhaps long-term outcomes. Yet, pain-control measures are adopted infrequently because of unresolved scientific issues and lack of appreciation for the need for control of pain and its long-term sequelae during the critical phases of neurologic maturation in the preterm and term newborn. The neonatal pain-control group, as part of the Newborn Drug Development Initiative (NDDI) Workshop I, addressed these concerns. The specific issues addressed were (1) management of pain associated with invasive procedures, (2) provision of sedation and analgesia during mechanical ventilation, and (3) mitigation of pain and stress responses during and after surgery in the newborn infant. The cross-cutting themes addressed within each category included (1) clinical-trial designs, (2) drug prioritization, (3) ethical constraints, (4) gaps in our knowledge, and (5) future research needs. This article provides a summary of the discussions and deliberations. Full-length articles on procedural pain, sedation and analgesia for ventilated infants, perioperative pain, and study designs for neonatal pain research were published in Clinical Therapeutics (June 2005).

Analgesia and anesthesia for neonates: Study design and ethical issues

OBJECTIVE

The purpose of this article is to summarize the clinical, methodologic, and ethical considerations for researchers interested in designing future trials in neonatal analgesia and anesthesia, hopefully stimulating additional research in this field.

METHODS

The MEDLINE, PubMed, EMBASE, and Cochrane register databases were searched using subject headings related to infant, newborn, neonate, analgesia, anesthesia, ethics, and study design. Cross-references and personal files were searched manually. Studies reporting original data or review articles related to these topics were assessed and critically evaluated by experts for each topical area. Data on population demographics, study characteristics, and cognitive and behavioral outcomes were abstracted and synthesized in a systematic manner and refined by group members. Data synthesis and results were reviewed by a panel of independent experts and presented to a wider audience including clinicians, scientists, regulatory personnel, and industry representatives at the Newborn Drug Development Initiative workshop. Recommendations were revised after extensive discussions at the workshop and between committee members.

RESULTS

Designing clinical trials to investigate novel or currently available approaches for analgesia and anesthesia in neonates requires consideration of salient study designs and ethical issues. Conditions requiring treatment include pain/stress resulting from invasive procedures, surgical operations, inflammatory conditions, and routine neonatal intensive care. Study design considerations must define the inclusion and exclusion criteria, a rationale for stratification, the confounding effects of comorbid conditions, and other clinical factors. Significant ethical issues include the constraints of studying neonates, obtaining informed consent, making risk-benefit assessments, defining compensation or rewards for participation, safety considerations, the use of placebo controls, and the variability among institutional review boards in interpreting federal guidelines on human research. For optimal study design, investigators must formulate well-defined study questions, choose appropriate trial designs, estimate drug efficacy, calculate sample size, determine the duration of the studies, identify pharmacokinetic and pharmacodynamic parameters, and avoid drug-drug interactions. Specific outcome measures may include scoring on pain assessment scales, various biomarkers and their patterns of response, process outcomes (eg, length of stay, time to extubation), intermediate or long-term outcomes, and safety parameters.

CONCLUSIONS

Much more research is needed in this field to formulate a scientifically sound, evidence-based, and clinically useful framework for management of anesthesia and analgesia in neonates. Newer study designs and additional ethical dilemmas may be defined with accumulating data in this field.

Does neonatal surgery lead to increased pain sensitivity in later childhood?

Does pain or tissue damage in early life lead to hyperalgesia persisting into childhood? We performed a cross-sectional study in 164 infants to investigate whether major surgery within the first 3 months of life increases pain sensitivity to subsequent surgery and to elucidate whether subsequent surgery in the same dermatome or in a different dermatome leads to differences in pain sensitivity. All infants received standard intraoperative and postoperative pain management, with rescue analgesia guided by a treatment algorithm. Differences in pain sensitivity during surgery were assessed by the intraoperative fentanyl intake and by (nor)epinephrine plasma concentrations. Differences in postoperative pain sensitivity were assessed by the observational pain measures COMFORT and VAS, and by morphine intake and (nor)epinephrine plasma concentrations. Infants previously operated upon in the same dermatome needed more intraoperative fentanyl, had higher COMFORT and VAS scores, had greater (nor)epinephrine plasma concentrations, and needed also more morphine than did infants with no prior surgery. In contrast, infants who previously underwent surgery in another dermatome had only significant higher postoperative analgesic requirements and norepinephrine plasma concentrations in comparison with infants with no prior surgery. These preliminary differences may indicate the occurrence of spinal and supraspinal changes following neonatal surgery. We conclude that the long-term consequences of surgery in early infancy are greater in areas of prior tissue damage and that these effects may portend limited clinical but important neurobiological differences.

Glutamine supplementation of parenteral nutrition does not improve intestinal permeability, nitrogen balance, or outcome in newborns and infants undergoing digestive-tract surgery: results from a double-blind, randomized, controlled trial

OBJECTIVE

To assess the effect of isocaloric isonitrogenous parenteral glutamine supplementation on intestinal permeability and nitrogen loss in newborns and infants after major digestive-tract surgery.

SUMMARY BACKGROUND DATA

Glutamine supplementation in critically ill and surgical adults may normalize intestinal permeability, attenuate nitrogen loss, improve survival, and lower the incidence of nosocomial infections. Previous studies in critically ill children were limited to very-low-birthweight infants and had equivocal results.

METHODS

Eighty newborns and infants were included in a double-blind, randomized trial comparing standard parenteral nutrition (sPN; n = 39) to glutamine-supplemented parenteral nutrition (GlnPN; glutamine target intake, 0.4 g kg day; n = 41), starting on day 2 after major digestive-tract surgery. Primary endpoints were intestinal permeability, as assessed by the urinary excretion ratio of lactulose and rhamnose (weeks 1 through 4); nitrogen balance (days 4 through 6), and urinary 3-methylhistidine excretion (day 5). Secondary endpoints were mortality, length of stay in the ICU and the hospital, number of septic episodes, and usage of antibiotics and ICU resources.

RESULTS

Glutamine intake plateaued at 90% of the target on day 4. No differences were found between patients assigned sPN and patients assigned GlnPN regarding any of the endpoints. Glutamine supplementation was not associated with adverse effects.

CONCLUSIONS

In newborns and infants after major digestive-tract surgery, we did not identify beneficial effects of isonitrogenous, isocaloric glutamine supplementation of parenteral nutrition. Glutamine supplementation in these patients therefore is not warranted until further research proves otherwise.

Postoperative pain assessment in the neonatal intensive care unit

OBJECTIVES

To compare the convergent validity of two measures of pain (premature infant pain profile (PIPP) and crying, requires oxygen, increased vital signs, expression, and sleepless (CRIES)) in real life postoperative pain assessment in infants.

METHODS

This study was a prospective, repeated measures, correlational design. Two staff nurses were randomly assigned either the PIPP or CRIES measure. An expert rater assessed each infant after surgery, and once a day using the visual analogue scale (VAS).

SETTING

A level III neonatal intensive care unit in a metropolitan university affiliated paediatric hospital.

RESULTS

Pain was assessed in 51 neonates (28-42 weeks of gestational age) after surgery. There was no significant difference in the rates of change between the pain assessment measures across time using repeated measures analysis of variance (F(50,2) = 0.62, p = 0.540), indicating correlation between the measures. Convergent validity analysis using intraclass correlation showed correlation, most evident in the first 24 hours (immediately, 4, 8, 20, and 24 hours after the operation). Correlations were more divergent at 40 and 72 hours after surgery. No significant interactions were found between gestational age and measure (F(304,4) = 0.75, p = 0.563) and surgical group and measure (F(304,2) = 0.39, p = 0.680).

CONCLUSIONS

PIPP and CRIES are valid measures that correlate with pain for the first 72 hours after surgery in term and preterm infants. Both measures would provide healthcare professionals with an objective measure of a neonatal patient's pain.

Major abdominal surgery of the neonate: anaesthetic considerations

The anaesthetic handling of neonates scheduled for major abdominal surgical procedures is one of the most demanding tasks that can confront an anaesthesiologist. This chapter will review the specific physiological characteristics of the newborn with relevance to anaesthesia and will also provide robust guidelines for the anaesthetic handling of the most frequent diagnoses that need major abdominal surgery during the neonatal period.

Use of intravenous ketorolac in the neonate and premature babies

BACKGROUND

Ketorolac is a powerful nonsteroidal anti-inflammatory drug widely used for pain control in children and adults. The aim of this study was to evaluate its safety and analgesic efficacy in the neonate.

METHODS

Ketorolac was used in a group of 18 spontaneously breathing neonates presenting with chronic lung disease, for the control of postsurgical pain and pain from invasive procedures. Pain scores (Neonatal Infant Pain Scale) were assessed before and after i.v. administration of 1 mg.kg(-1) of ketorolac.

RESULTS

Total pain control was achieved in 94.4% of the neonates. None of the neonates had haematological, renal or hepatic changes prior to treatment, and these complications did not occur after treatment. No neonate had systemic haemorrhage or bleeding from injection and blood withdrawal sites.

CONCLUSIONS

Ketorolac could represent an efficacious analgesic alternative to opioids, particularly in neonates. It would avoid the side-effects associated with opioid analgesics, especially respiratory depression.

Critically Low Hormone and Catecholamine Concentrations in the Primed Extracorporeal Life Support Circuit

The first hours of extracorporeal life support (ECLS) are commonly marked by new hemodynamic instability without a known etiology. We measured hormone and catecholamine concentrations in six ECLS primed circuits immediately before joining the patient's circulation to assess a potential role of these agents in this condition. The following hormones were significantly below the lower end of the normal range for the first week of life (data are presented as mean +/- SEM): cortisol 1.95 +/- 0.15 microg/dl (p < 0.001), aldosterone 3.73 +/- 0.74 ng/dl (p < 0.05), free thyroxine 1.2 +/- 0.1 ng/dl (p < 0.05), free triiodothyronine 0.53 +/- 0.03 pg/ml (p < 0.001), thyroid stimulating hormone 0.31 +/- 0.05 microU/ml (p < 0.001), growth hormone (GH) 0.09 +/- 0.01 ng/ml (p < 0.001), estradiol 38.3 +/- 3.72 pg/ml (p < 0.001), IGF-BP1 0.95 +/- 0.1 ng/ml (p < 0.001), glucagon 26 +/- 1.2 pg/ml (p < 0.001), epinephrine 17.3 +/- 3.7 pg/ml (p < 0.001), and norepinephrine 127 +/- 27 pg/ml (p < 0.05). No dopamine was detected. Normal hormone concentrations included IGF-I, IGF-BP3, insulin, parathyroid hormone, leptin, and testosterone. Critically low concentrations of cortisol, thyroid hormones, GH, IGF-BP1, glucagon and catecholamines were measured in the ECLS circuit even though it was primed with fresh frozen plasma. These concentrations may cause significant and precipitous dilutional reductions in the patient's circulating levels immediately after connection to the ECLS circuit and hence contribute to hemodynamic instability.

Age- and therapy-related effects on morphine requirements and plasma concentrations of morphine and its metabolites in postoperative infants

BACKGROUND

To investigate clinical variables such as gestational age, sex, weight, the therapeutic regimens used and mechanical ventilation that might affect morphine requirements and plasma concentrations of morphine and its metabolites.

METHODS

In a double-blind study, neonates and infants stratified for age [group I 0-4 weeks (neonates), group II > or =4-26 weeks, group III > or =26-52 weeks, group IV > or =1-3 yr] admitted to the paediatric intensive care unit after abdominal or thoracic surgery received morphine 100 micro g kg(-1) after surgery, and were randomly assigned to either continuous morphine 10 micro g kg(-1) h(-1) or intermittent morphine boluses 30 micro g kg(-1) every 3 h. Pain was measured using the COMFORT behavioural scale and a visual analogue scale. Additional morphine was administered on guidance of the pain scores. Morphine, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) plasma concentrations were measured before, directly after, and at 6, 12 and 24 h after surgery.

RESULTS

Multiple regression analysis of different variables revealed that age was the most important factor affecting morphine requirements and plasma morphine concentrations. Significantly fewer neonates required additional morphine doses compared with all other age groups (P<0.001). Method of morphine administration (intermittent vs continuous) had no significant influence on morphine requirements. Neonates had significantly higher plasma concentrations of morphine, M3G and M6G (all P<0.001), and significantly lower M6G/morphine ratio (P<0.03) than the older children. The M6G/M3G ratio was similar in all age groups.

CONCLUSIONS

Neonates have a narrower therapeutic window for postoperative morphine analgesia than older age groups, with no difference in the safety or effectiveness of intermittent doses compared with continuous infusions in any of these age groups. In infants >1 month of age, analgesia is achieved after morphine infusions ranging from 10.9 to 12.3 micro g kg(-1) h(-1) at plasma concentrations of <15 ng ml(-1).

Assessment and management of acute pain in high-risk neonates

Neonates in the neonatal intensive care unit experience hundreds of painful procedures at a time of rapid neurological development. Although the immediate responses to pain may be protective, the potential long-term effects of early and under-treated pain are concerning. As pain assessment is the first step in the provision of appropriate and timely pain management, attention should be directed to the quantification of pain in terms of its location, severity, intensity and duration. Over the past decade, numerous pain measures have been developed for preterm and term neonates, however, most of them have been developed for research purposes and have not been tested in the clinical setting. In order to effectively implement pain measures in the clinical setting, the psychometric properties of reliability, validity, feasibility and clinical utility must be established. This review paper will highlight the importance of neonatal pain assessment and examine the psychometric properties of various measures of neonatal pain. Pharmacological and non-pharmacological interventions to manage acute pain in high-risk neonates will be addressed and future research topics will be proposed.

Are postoperative pain instruments useful for specific groups of vulnerable infants?

Based on the authors' review of the literature on pediatric postoperative pain assessment with special attention to groups of vulnerable infants, this article (1) reports on type of surgery and its relationship to postoperative pain intensity; (2) reviews the characteristics of existing postoperative pain instruments for neonates, infants, and toddlers; (3) discusses timing, duration, and who should assess postoperative pain; (4) reviews the specific literature on pain assessment in critically ill infants, including the extremely low birth weight and the cognitively and/or neurologically impaired infant, and (5) discusses the role of parents in postoperative pain assessment. Postoperative pain instruments are useful for specific groups of vulnerable infants, but it is important that in addition to the valuable scoring of pain, common sense is used and factors such as developmental stage, temperament and personality, number of previous painful experiences, anxiety, and environmental factors are taken into account.

Nutritional support of the critically ill child

The pediatric metabolic response to injury and operation is proportional to the degree of stress and causes an increase in the turnover of proteins, fats, and carbohydrates. Thereby, substrates are made readily available for the immune response and wound healing. Because this process requires energy, the resting energy expenditure of ill patients increases. Whole-body protein degradation rates are elevated out of proportion to synthetic rates, and negative protein balance also ensues. Neonates and children are particularly susceptible to the loss of lean body mass and its attendant increased morbidity and mortality caused by an intrinsic lack of endogenous stores and greater baseline requirements. An appropriately designed mixed fuel system of nutritional support replete in protein does not quell this metabolic response but can result in anabolism and continued growth in ill children. In addition, the use of adequate analgesia and anesthesia is a readily available and proven means of reducing the magnitude of the catabolism associated with operation and injury. Finally, as hormonal- and cytokine-mediated metabolic alterations are better understood, therapeutic interventions may become available to directly modulate the metabolic response to illness, thus potentially further improving clinical outcome in pediatric surgical patients.

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.

Retrospective evaluation of continuous epidural infusion for postoperative pain in children

BACKGROUND

The safety and efficacy of postoperative epidural analgesia (EDA) in children are not well documented in larger series of patients given routine postoperative care. The aims of this study were to evaluate the efficacy of pain relief, determine the incidence and type of complications during the entire period of epidural pain treatment in children, and assess the factors affecting efficacy

METHODS

Children treated postoperatively with an EDA infusion during the period 18 September 1994 to 1 January 1999 were studied. Data regarding the age, gender, efficacy of analgesia, duration of epidural infusion, types of side-effects and complications, reasons for discontinuation, and types and duration of surgery were collected daily by the Acute Pain Treatment Service. The sensory dermatomal level of the surgical incision site was included retrospectively.

RESULTS

Five hundred and eighteen epidural infusions were given to 476 children. Pain relief was rated as 'good' at 76% of visits. There were no major complications or sequelae. Thirty-seven per cent of the epidural infusions were prematurely discontinued, and 21% were discontinued because of unsatisfactory analgesia. Factors related to a higher percentage of unsatisfactory function were surgical incision site located above the umbilicus, gastroenterologic surgery, protracted surgery and age. Age and duration of surgery were significantly related to unsatisfactory function.

CONCLUSION

This study shows that continuous epidural infusion for postoperative pain was satisfactory in most cases, and that no major side-effects or complications occurred in children nursed on regular wards. The early recognition of unsatisfactory function of an EDA is important for a child's well being.