Postoperative analgesia in children: a prospective study in intermittent intramuscular injection versus continuous intravenous infusion of morphine

Consistency of pediatric pain ratings between dyads: an updated meta-analysis and metaregression

Accurate assessment of pediatric pain remains a challenge, especially for children who are preverbal or unable to communicate because of their health condition or a language barrier. A 2008 meta-analysis of 12 studies found a moderate correlation between 3 dyads (child-caregiver, child-nurse, and caregiver-nurse). We updated this meta-analysis, adding papers published up to August 8, 2021, and that included intraclass correlation/weighted kappa statistics (ICC/WK) in addition to standard correlation. Forty studies (4,628 children) were included. Meta-analysis showed moderate pain rating consistency between child and caregiver (ICC/WK = 0.51 [0.39-0.63], correlation = 0.59 [0.52-0.65], combined = 0.55 [0.48-0.62]), and weaker consistency between child and health care provider (HCP) (ICC/WK = 0.38 [0.19-0.58], correlation = 0.49 [0.34-0.55], combined = 0.45; 95% confidence interval 0.34-0.55), and between caregiver and HCP (ICC/WK = 0.27 [-0.06 to 0.61], correlation = 0.49 [0.32 to 0.59], combined = 0.41; 95% confidence interval 0.22-0.59). There was significant heterogeneity across studies for all analyses. Metaregression revealed that recent years of publication, the pain assessment tool used by caregivers (eg, Numerical Rating Scale, Wong-Baker Faces Pain Rating Scale, and Visual Analogue Scale), and surgically related pain were each associated with greater consistency in pain ratings between child and caregiver. Pain caused by surgery was also associated with improved rating consistency between the child and HCP. This updated meta-analysis warrants pediatric pain assessment researchers to apply a comprehensive pain assessment scale Patient-Reported Outcomes Measurement Information System to acknowledge psychological and psychosocial influence on pain ratings.

The optimal choice of medication administration route regarding intravenous, intramuscular, and subcutaneous injection

BACKGROUND

Intravenous (IV), intramuscular (IM), and subcutaneous (SC) are the three most frequently used injection routes in medication administration. Comparative studies of SC versus IV, IM versus IV, or IM versus SC have been sporadically conducted, and some new findings are completely different from the dosage recommendation as described in prescribing information. However, clinicians may still be ignorant of such new evidence-based findings when choosing treatment methods.

METHODS

A literature search was performed using PubMed, MEDLINE, and Web of Sciences™ Core Collection to analyze the advantages and disadvantages of SC, IV, and IM administration in head-to-head comparative studies.

RESULTS

"SC better than IV" involves trastuzumab, rituximab, antitumor necrosis factor medications, bortezomib, amifostine, recombinant human granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, recombinant interleukin-2, immunoglobulin, epoetin alfa, heparin, and opioids. "IV better than SC" involves ketamine, vitamin K1, and abatacept. With respect to insulin and ketamine, whether IV has advantages over SC is determined by specific clinical circumstances. "IM better than IV" involves epinephrine, hepatitis B immu-noglobulin, pegaspargase, and some antibiotics. "IV better than IM" involves ketamine, morphine, and antivenom. "IM better than SC" involves epinephrine. "SC better than IM" involves interferon-beta-1a, methotrexate, human chorionic gonadotropin, hepatitis B immunoglobulin, hydrocortisone, and morphine. Safety, efficacy, patient preference, and pharmacoeconomics are four principles governing the choice of injection route. Safety and efficacy must be the preferred principles to be considered (eg, epinephrine should be given intramuscularly during an episode of systemic anaphylaxis). If the safety and efficacy of two injection routes are equivalent, clinicians should consider more about patient preference and pharmacoeconomics because patient preference will ensure optimal treatment adherence and ultimately improve patient experience or satisfaction, while pharmacoeconomic concern will help alleviate nurse shortages and reduce overall health care costs. Besides the principles, the following detailed factors might affect the decision: patient characteristics-related factors (body mass index, age, sex, medical status [eg, renal impairment, comorbidities], personal attitudes toward safety and convenience, past experience, perception of current disease status, health literacy, and socioeconomic status), medication administration-related factors (anatomical site of injection, dose, frequency, formulation characteristics, administration time, indication, flexibility in the route of administration), and health care staff/institution-related factors (knowledge, human resources).

CONCLUSION

This updated review of findings of comparative studies of different injection routes will enrich the knowledge of safe, efficacious, economic, and patient preference-oriented medication administration as well as catching research opportunities in clinical nursing practice.

The relationship between age and morphine infusion rate in children

AIM

We performed a retrospective audit of intravenous morphine infusion administered to children in an effort to characterize the relationship between dose and age.

METHODS

A retrospective audit of morphine infusions was reviewed for a 24-months period and included all children who received continuous intravenous nurse-controlled morphine infusions and patient-controlled analgesia; a population undergoing acute and elective surgical procedures, as well as medical and oncological treatments. The relationship between age and infusion rate was investigated using nonlinear mixed effects models.

RESULTS

There were 886 children whose data were acceptable for review. Morphine dose increased with age from 9.97 (CV 28%) μg · kg(-1) per h in neonates. The Hill equation with an exponential of 1.5 best described these changes. Morphine rate reached 90% of its mean final rate of 22.5 (CV 167%) μg · kg(-1) per h, observed in teenagers, at approximately 5 years of age. There was considerable uncertainty of this age-morphine rate profile, and the maturation half-life of this profile was 20 months of age (CV 632%). An increase in dosing variability was observed with increasing age.

CONCLUSIONS

Morphine infusions at steady-state did not mirror clearance maturation in children nursed in our hospital. We suggest that initial infusion rates in children are started at 10 μg · kg(-1) per h in neonates, 15 μg · kg(-1) per h in toddlers and 25 μg · kg(-1) per h in children above the age of 5 years. The large variability associated with infusion rates means that subsequent infusion rates will depend on feedback from pain scores, adjuvant medications and adverse effects.

Prediction of morphine dose in humans

BACKGROUND

Morphine is widely used throughout the human life span. Several pharmacokinetic models have been proposed to predict how morphine clearance changes with weight and age. This study uses a large external data set to evaluate the ability of pharmacokinetic models to predict morphine doses.

METHODS

A data set of morphine clearance estimates was created from published reports in premature neonates, full-term neonates, infants, children, and adults. This external data set was used to evaluate published models for morphine clearance as well as other models proposed for use in neonates and infants. Morphine clearance predictions were used to predict morphine dose rates to achieve similar target concentrations in all age groups.

RESULTS

An allometric ¾ power model using weight combined with a sigmoid maturation model using postmenstrual age successfully predicted the morphine dose rate (within 25% of target) in all age groups except infants [predicted dose 30% under target (95% CI, 7-46%)]. Other published models based on empirical allometric scaling all made unacceptable predictions (>100% of target) in at least one age group.

CONCLUSIONS

Clearance based on empirical allometric scaling predicted unacceptable doses. Theory-based allometric scaling combined with a maturation function has been confirmed by external evaluation to provide a sound basis for describing clearance and predicting morphine doses in humans of all ages.

Pharmacokinetics and analgesic effects of intravenous propacetamol vs rectal paracetamol in children after major craniofacial surgery

BACKGROUND

The pharmacokinetics and analgesic effects of intravenous and rectal paracetamol were compared in nonventilated infants after craniofacial surgery in a double-blind placebo controlled study.

METHODS

During surgery all infants (6 months-2 years) received a rectal loading dose of 40 mg.kg(-1) paracetamol 2 h before anticipated extubation. On admittance to the pediatric surgical ICU, the children were randomized to receive either a 15 min intravenous infusion of 40 mg.kg(-1) propacetamol, a prodrug of paracetamol, or 20 mg.kg(-1) paracetamol rectally every 6 h. A population pharmacokinetic analysis of the paracetamol plasma concentration time-profiles was undertaken using nonlinear mixed effects models. The visual analogue scale (VAS) (score 0-10 cm) and COMFORT Behavior scale (score 6-30) were used to monitor analgesia in the 24-h period following surgery.

RESULTS

Twelve infants received intravenous propacetamol and 14 paracetamol suppositories. Paracetamol pharmacokinetics were described according to a two-compartmental model with linear disposition. Pharmacokinetic parameters were standardized to a 70 kg person using allometric '1/4 power' models. Parameter estimates were: absorption half-life from the rectum 4.6 h, propacetamol hydrolysis half-life 0.028 h, clearance 12 l.h(-1).70 kg(-1), intercompartmental clearance 116 l.h(-1).70 kg(-1), central and peripheral volume of distribution 7.9 and 44 l.70 kg(-1), respectively. During the 24-h study period 22 infants exhibited VAS scores <4 cm, which was considered a cutoff point. On single occasions four patients, two in each group, exhibited a VAS score >/=4 cm. Nine patients in the rectal treatment group and three patients in the intravenous treatment group received midazolam for COMFORT-B scores exceeding 17 (P < 0.05).

CONCLUSIONS

Intravenous propacetamol proved to be more effective than rectal paracetamol in infants after craniofacial surgery. Midazolam was more frequently administered to patients receiving paracetamol suppositories, indicating that these children experienced more distress, possibly caused by pain.

A comparison of analgesic efficacy of tramadol and pethidine for management of postoperative pain in children: a randomized, controlled study

Prevention of postoperative pain in children is one of the most important objectives of the anesthesiologist. Opioids have been used as an analgesic for postoperative pain in children for many years. Tramadol has both opioid and monoaminergic agonist actions. The aim of the study was to determine if the analgesic potency and occurrence of adverse effects of tramadol differ from pethidine when administered to children. A total of 110 healthy children, aged 2-12 years, scheduled for elective lower abdominal surgery were randomized to receive either pethidine 1 mg/kg (Group I, n = 60) or tramadol 2 mg/kg (Group II, n = 50) for postoperative pain after anesthesia induction. Pain intensity, adverse effects, heart rate, and systolic and diastolic blood pressure were recorded at regular intervals. The mean pain scores on postoperative 24 h were significantly greater with tramadol than with pethidine. Sedation scores, heart rate and systolic and diastolic blood pressure showed no significant differences between the groups. We conclude that pethidine and tramadol are effective in providing analgesia in pediatric patients, but pethidine provided better postoperative analgesia than tramadol. Changes in blood pressure, heart rate and arterial oxygen saturation were minimal and were similar in both drugs.

Analysis of the validation of existing behavioral pain and distress scales for use in the procedural setting

BACKGROUND

Assessing procedural pain and distress in young children is difficult. A number of behavior-based pain and distress scales exist which can be used in preverbal and early-verbal children, and these are validated in particular settings and to variable degrees.

METHODS

We identified validated preverbal and early-verbal behavioral pain and distress scales and critically analysed the validation and reliability testing of these scales as well as their use in procedural pain and distress research. We analysed in detail six behavioral pain and distress scales: Children's Hospital of Eastern Ontario Pain Scale (CHEOPS), Faces Legs Activity Cry Consolability Pain Scale (FLACC), Toddler Preschooler Postoperative Pain Scale (TPPPS), Preverbal Early Verbal Pediatric Pain Scale (PEPPS), the observer Visual Analog Scale (VASobs) and the Observation Scale of Behavioral Distress (OSBD).

RESULTS

Despite their use in procedural pain studies none of the behavioral pain scales reviewed had been adequately validated in the procedural setting and validation of the single distress scale was limited.

CONCLUSIONS

There is a need to validate behavioral pain and distress scales for procedural use in preverbal or early-verbal children.

Pharmacokinetics and physiological effects of two intravenous infusion rates of morphine in conscious dogs

This study examined the pharmacokinetics and physiologic effects of two infusions rates of morphine in conscious dogs. Five adult dogs were randomly studied at weekly intervals. An initial dose of either 0.3 or 0.6 mg/kg were each followed by infusions of 0.17 and 0.34 mg/kg/h. Plasma morphine concentrations, physiological parameters, sedation and mechanical antinociception were evaluated during each infusion. Morphine was assayed by high pressure liquid chromatography (HPLC) with electrochemical coulometric detection and pharmacokinetic parameters were calculated. Data were fitted to a bi-compartment model with a rapid distribution (<1 min for both doses) and slower termination rate. For the high and low doses, respectively, mean+/-SD terminal half-life was 38+/-5 and 27+/-14 min, apparent volumes of distribution at steady-state were 1.9+/-0.5 and 1.3+/-0.8 L/kg, with clearances of 50+/-15 and 67+/-20 mL/kg/min. Steady-state plasma concentrations ranged from 93 to 180 ng/mL and 45 to 80 ng/mL in the high and low doses, respectively. Respiratory rate increased significantly, pulse oximetry remained>95% and body temperature decreased significantly during both infusions. No vomition or neuroexcitation occurred. Sedation and mechanical antinociception were both mild during the lower infusion rate, and mild to moderate during the higher infusion rate. In conclusion, morphine pharmacokinetics was not altered by increasing infusion rates, producing stable, long-lasting plasma concentrations.

Treatment in the pediatric emergency department is evidence based: a retrospective analysis

BACKGROUND

Our goal was to quantify the evidence that is available to the physicians of a pediatric emergency department (PED) in making treatment decisions. Further, we wished to ascertain what percentage of evidence for treatment provided in the PED comes from pediatric studies.

METHODS

We conducted a retrospective chart review of randomly selected patients seen in the PED between January 1 and December 31, 2002. The principal investigator identified a primary diagnosis and primary intervention for each chart. A thorough literature search was then undertaken with respect to the primary intervention. If a randomized control trial (RCT) or a systematic review was found, the intervention was classified as level I evidence. If no RCT was found, the intervention was assessed by an expert committee who determined its appropriateness based on face validity (RCTs were unanimously judged to be both unnecessary and, if a placebo would have been involved, unethical). These interventions were classified as level II evidence. Interventions that did not fall into either above category were classified as level III evidence.

RESULTS

Two hundred and sixty-two patient charts were reviewed. Of these, 35.9% did not receive a primary intervention. Of the 168 interventions assessed, 80.4% were evidence-based (level I), 7.1% had face validity (level II) and 12.5% had no supporting evidence (level III). Of the evidence-based interventions, 83.7% were supported by studies with mostly pediatric patients.

CONCLUSION

Our study demonstrates that a substantial proportion of PED treatment decisions are evidence-based, with most based on studies in pediatric patients. Also, a large number of patients seen in the PED receive no intervention.

Evaluation of histamine release during constant rate infusion of morphine in dogs

OBJECTIVE

To evaluate histamine release and selected physiologic variables during constant rate infusion (CRI) of morphine in dogs.

ANIMALS

Five healthy, conscious, intact female dogs.

MATERIAL AND METHODS

Using a Latin square, repeated-measures design, dogs were randomly assigned to three treatment groups to receive a 4-hour CRI of saline (SAL), or a loading dose of morphine at 0.3 mg kg(-1) (LM), or 0.6 mg kg(-1) (HM), followed by an infusion of 0.17 mg kg(-1) hour(-1) (LM) and 0.34 mg kg(-1) hour(-1) (HM) respectively. Dogs received each of the three treatments at intervals of at least 7 days. Plasma histamine concentration, skin flushing, edema and wheals, heart rate and rhythm and non-invasive arterial blood pressure were measured before the loading dose and at 1, 2, 5, 15, 30, 60, 120, 180 and 240 minutes during the CRI, or at the time of occurrence.

RESULTS

The loading dose induced the highest histamine release in the HM group being statistically higher than the SAL group. The histamine release obtained in the LM group after the loading dose did not differ from SAL. During the infusion, plasma histamine levels were numerically higher in the LM group. Besides one dog that developed hypotension for 2 minutes after the loading dose in the HM group and one dog that showed occasional ventricular premature contractions during both morphine infusions, cardiovascular variables were similar among the three treatment groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Both doses of morphine induced variable histamine release with minimal adverse cardiovascular effects in these conscious, healthy dogs. The plasma histamine levels obtained may be associated with significant hemodynamic changes in patients with limited cardiovascular reserve and sympathetic nervous tone.

Prevention and treatment of postoperative pain with particular reference to children

Pain therapy is an important aspect of medical practice for patients of all ages, to optimize care, to obtain an adequate quality of life and to improve their general conditions. Pain is among the most prevalent symptoms experienced by patients undergoing surgery. The success of postoperative pain therapy depends on the ability of the clinician to assess the presenting problems, identify and evaluate pain syndromes and formulate a plan for comprehensive continuing care. The prevalence of acute pain has led to the need to develop techniques for the assessment and management of this symptom in order to focus the attention on an interdisciplinary therapeutic approach (including pharmacologic, cognitive-behavioral, psychologic and physical treatment) and on the timing of different interventions (pre and postoperative). In this chapter we describe the principal therapeutic approaches to control pain in post-operative patients, such as non-opioid, opioid and adjuvant analgesics with particular attention in paediatric age. Moreover we report the principal scales to assess the pain intensity in the post-operative period. The need of a multidisciplinatory team and of a pre and postoperative pain management program represents an important goal in order to obtain effective pain relief and optimize pediatric care and rapid recovery. The introduction of a perioperative team service will improve the approach to pain management programs and it is considered the most important challenge for future.

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).

Observational visual analog scale in pediatric pain assessment: useful tool or good riddance?

DESIGN

The authors reviewed the available pediatric pain literature and selected those studies that reported quantitative information on the reliability and validity of, and the optimal cutoff points for, the visual analog scale (VAS) when used as an observational pediatric pain tool.

RESULTS

Available psychometric findings concerning the observational VAS (VAS obs ) are limited. The estimated interrater reliability of the VAS (obs) from 9 studies ranged from 0.36 to 0.91. The correlation between self-report and the VAS (obs) was variable and ranged 0.23 to 0.83 in 6 studies. The concurrent validity of the VAS (obs) and other pain instruments ranged from 0.42 to 0.86.

CONCLUSIONS

Further psychometric testing needs to be conducted on intraobserver reliability, responsiveness, and optimal cutoff points. Future research may guide the choice between VAS (obs) and the numerous behavioral pain instruments.

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.

Patterns of analgesic use in trauma patients in the ED

The objective was to describe patterns of analgesic use for trauma patients treated in our emergency department (ED). We reviewed analgesic use in consecutive patients meeting American College of Surgeons (ACS) Trauma Center Guidelines. A comprehensive database was abstracted from this institution's Trauma Registry and medical records of each patient. A total of 38% (95% CI: 31-46%) of patients received analgesics. Time to administration of first dose of analgesia was 109 minutes (95% CI: 85-133). Women, patients with long bone and pelvic fractures, and those with a longer ED stay were most likely to receive analgesics. Patients with head trauma and those admitted to the intensive care unit were least likely to receive analgesics. Morphine was the most frequent analgesic used with an average total dose of 14 milligrams. A majority of patients meeting ACS Trauma Center Guidelines did not receive analgesics in the ED.

Pain treatment thresholds in children after major surgery

OBJECTIVE

The objectives of this study were to use a self-report pain scale to examine child pain treatment thresholds after major surgery (i.e., the level of pain they are comfortable with before requiring analgesia), as well as to examine agreement between mother-, nurse-, and child-rated pain treatment thresholds.

METHODS

Twenty-five children aged 6 to 16 years were interviewed for 3 consecutive days after major surgery. Subjects used the Faces Pain Scale to rate their current pain, worst postoperative pain, and pain level at which they would like to receive analgesia (the pain treatment threshold). Parents and nurses also estimated the child pain treatment thresholds.

RESULTS

For day 1, mean pain was 1.86 of a maximum of 6, mean worst pain was 4.16, and mean pain treatment threshold was 2.28. For day 2, these values were 1.90, 4.10, and 2.54, and for day 3 they were 1.62, 4.56, and 1.85, respectively. Mean scores for all 3 days were as follows: pain, 1.79; worst pain, 4.15; and pain treatment threshold, 2.33. Although mother-nurse ratings were correlated (0.471), mother-child and nurse-child ratings were not significantly correlated. Using the pain treatment threshold as the criterion, 36% of our subjects were undermedicated after the first day of surgery.

CONCLUSION

Pain treatment thresholds seem to be lower in children after major as compared with minor surgery. Parents and nurses are not accurate in rating child pain treatment thresholds. Parents tended to overestimate their child's pain treatment threshold, whereas nurses were less consistent in their scoring.

Efficacy and complications of morphine infusions in postoperative paediatric patients

The aim of the study was to evaluate the efficacy and the incidence of clinically significant adverse drug reactions (ADRs) in paediatric patients receiving continuous intravenous morphine infusions for acute postoperative pain. Definitions were established for ADRs and data were collected in an immediately retrospective fashion for a maximum of 72 h in 110 patients >/=5 three months of age (0.3-16.7 years) receiving morphine infusions and admitted to a general ward over a three month convenience sampling period. Inadequate analgesia occurred in 65.5% of patients during the first 24 h of therapy and occurred most frequently in patients with infusion rates of 20 microg.kg-1.h-1 or less. Nausea/vomiting was the most commonly experienced ADR (42.5%). The incidence of respiratory depression was 0% (95% CI=0-3.3%). Other ADRs included: urinary retention (13.5%), pruritus (12.7%), dysphoria (7.3%), hypoxaemia (4.5%), discontinuation of morphine for treatment of an ADR (3.6%), and difficulty in arousal (0.9%). The most common ADRs associated with morphine infusions were inadequate analgesia (in the first 24 h) and nausea/vomiting. There were no cases of respiratory depression. Methods of avoiding initial inadequate analgesia and treating nausea and vomiting associated with morphine infusions are needed.

Patient controlled analgesia in children and adolescents: a randomized controlled trial

In children, patient controlled analgesia (PCA) and continuous infusion (CI) of morphine are well established methods of relieving postoperative pain. This study was designed to assess the efficacy of PCA plus background infusion (BI) (15 microg x kg(-1) x h(-1) and bolus doses of 15 microg x kg(-1) with a lock-out interval of 10 min) with CI (20 to 40 microg x kg(-1) x h(-1)) in terms of analgesia, morphine needs and side-effects. A stratified randomized controlled trial was carried out. 47 children aged 5-18 years undergoing major elective lower/upper abdominal or spinal surgery were allocated. The magnitude of surgery was assessed by the Severity of Surgical Stress scoring (SSS) system. Pain was assessed by self-report every three h. Side-effects compatible with morphine as well as morphine consumption were recorded. Morphine consumption was significantly increased in the PCA group compared with the CI group. Moreover, morphine consumption was associated with SSS, independent of the technique of administration. There were no significant differences between groups in pain scores or in the incidence of side-effects.

The respiratory effects of tramadol in children under halothane an anaesthesia

In a randomised double-blind, placebo-controlled study, the respiratory effects of intravenous tramadol (1 mg or 2 mg.kg-1) were compared with intravenous pethidine 1 mg.kg-1 under halothane anaesthesia. Children, ASA 1-2 between 2 and 10 years, presenting for inguinal surgery were studied. Once a steady state for halothane was reached, baseline recordings of end-tidal carbon dioxide, oxygen saturation, respiratory rate, tidal volume, minute volume, blood pressure and pulse rate were recorded. Intravenous tramadol 1 mg.kg-1 (T1) or 2 mg.kg-1 (T2) or pethidine 1 mg.kg-1 (PE) or placebo (PL) was then given according to a computer-generated randomisation. Further sets of recordings were taken at 5-min intervals for 20 min prior to commencement of surgery. The rate of recovery was assessed according to Aldrete scoring and the time and need for further analgesia were noted. The postoperative pain intensity was scored by means of a five-point verbal rating scale hourly for 6 h. Eighty-eight children, 22 per group, were studied. The mean age, weight and height were similar in each group. There was a statistically significant difference between the maximum decrease in respiratory rate and increase in end-tidal carbon dioxide between group PE and groups T1/T2 (p < 0.001). Thirteen episodes of apnoea occurred in the PE group, 11 requiring naloxone. The mean respiratory rate was lowest 5 min after injection in all groups. There was a slow increase in respiratory rate until incision in groups T1 and T2. Respiratory rate remained almost unchanged in PL until incision. The decreases in respiratory rate were reflected by increases in end-tidal carbon dioxide, the highest being recorded in the PE group. A lower intensity of pain in the first 2 h was noted in the three opioid groups. During the first 6 h, the proportion of patients requiring a further dose of analgesia was highest in PL and lowest in T2. Tramadol appears safe for use in children.

Pharmacologic pain management in children: a review of intervention research

In the past decade, an explosion of interest in pediatric pain has resulted in the proliferation of research studies. This review examines 41 studies that focus on pharmacologic interventions in children during the last decade. Criteria for inclusion in this paper were studies that (1) tested a pharmacological intervention prospectively, (2) were conducted with children only, (3) had a sample size over 30, (4) randomly assigned participants to two or more groups, and (5) provided sufficient methodological and statistical detail for critique. Studies focused on postoperative and procedural pain, were conducted most frequently with pre-school-aged children or older, and demonstrated the efficacy of pharmacologic interventions.

Recommended use of morphine in neonates, infants and children based on a literature review: Part 2--Clinical use

The indication for morphine use is primarily pain, but also a combined analgesic and sedative effect may be the rationale behind morphine administration. Paediatric morphine regimens have been reported for children with postoperative pain, pain related to cancer, sickle cell crisis pain, burns and AIDS. No dose response curve for morphine in neonates, infants or children has been established, and different levels for the minimum effective plasma concentration have been estimated. The side effects observed in neonates, infants, and children are similar to those observed in adults, and neonates do not seem to be more susceptible to respiratory depression than older children. Despite shortcomings in the knowledge of the pharmacodynamics of morphine, it can be considered safe to administer morphine to neonates, infants or children. Initial regimens has been calculated from the pharmacokinetic parameters of morphine, but treatment must be adjusted according to analgesic effect and incidence of side effects.

[Specific aspects of perioperative pain relief in children.]

Pain relief in children during the perioperative period can be provided by means of peripherally or centrally acting analgesics or of regional anaesthetic techniques. Narcotics or regional blockde are indicated when peripherally acting analgesics prove inadequate to abolish pain. Side effects of narcotics must be taken into account: opioids must not be administered unless continuous safety monitoring of the child's respiration is assured. If narcotics fail to relieve pain, regional anaesthesia may be indicated. All advantages and drawbacks of the various techniques that might be appropriate must be considered: the technique involving the least risk and side effects is the anaesthetic technique with a broad margin of safety when applied by an anaesthesiologist who has experience with paediatric regional blocks include topical anaesthesia, local infiltration, peripheral nerve blocks (e.g. nervi dorsalis penis, plexus axillaris) and caudal epidural blockade. Caution must be exercised whenever narcotics are administered systemically or epidurally; side effects must not be underestimated, even under conditions of intensive care observation. The provision of effective pain relief is a rewarding task-and particularly in little children.

Postoperative analgesia: opioid infusions in infants and children

The purpose of this review is to emphasise the ineffectiveness of traditional analgesic therapy in paediatric patients after surgery, to examine the sensation of pain in infants and children, and to describe the use of intravenous opioids for postoperative analgesia. The management of acute postoperative pain in the paediatric surgical population has been poor. This is despite the knowledge that infants and children have sufficient neurological development at birth to sense pain, and that the same hormonal and metabolic responses to nociceptive stimuli that occur in adult also occur in the neonate. Physicians frequently order analgesics in inappropriate doses, nurses are reluctant to administer opioids, and children themselves frequently compound the problem by refusing injections. The sophisticated techniques for providing postoperative analgesia which have been used so successfully in adults can also be used in paediatric patients. Two of these, continuous intravenous opioid infusion and patient-controlled analgesia, have proved to be very successful. Children older than six months can receive either modality safely with regular monitoring by qualified nursing staff. Infants younger than six months receiving continuous opioid infusions should be monitored in high-dependency units.

Clinicians' quick reference guide to acute pain management in infants, children, and adolescents: operative and medical procedures. Pain Management Guideline Panel. Agency for Health Care Policy and Research, US Department of Health and Human Services

The management of pain is an important part of a health professional's role. The challenge for clinicians is to balance pain control with concern for patient safety and side effects of pain treatments. This is the second of two articles presenting the clinical highlights of the Agency for Health Care Policy and Research's Panel to develop clinical practice guidelines for pain management. This article presents the clinical highlights related to the assessment and management of pain in infants and children.

Continuous paravertebral block for postthoracotomy analgesia in children

Six children with a mean age of 10.6 years (range, 7 to 16 years) underwent thoracotomy for pulmonary and esophageal procedures. Postoperatively, continuous paravertebral block using an infusion of bupivacaine via an extrapleural catheter was used. Excellent analgesia was attained in all patients, with no requirement for opiates or other analgesic drugs. There were no pulmonary complications and no complications related to the continuous extrapleural infusion. We conclude that continuous paravertebral block is an effective and safe method for ++post-thoracotomy pain relief in children.

Single-dose caudal epidural morphine in children: safe, effective, and easy

STUDY OBJECTIVE

To determine whether a single epidural dose of morphine sulfate is effective in providing 12- to 24-hour pain relief in children.

DESIGN

A chart review of 113 consecutive pediatric patients having received a single dose of epidural morphine.

SETTING

An inpatient anesthesia and surgical service at a regional children's hospital.

PATIENTS

One hundred thirteen consecutive pediatric patients from 2 months to 15 years old who underwent major orthopedic, thoracic, genitourinary, or abdominal surgical procedures.

INTERVENTIONS

60 micrograms/kg of preservative-free morphine sulfate was administered epidurally after induction of anesthesia but before surgery began. The epidural space was accessed caudally, and a total volume of 1 ml/kg to a maximum of 20 ml was injected. No other intraoperative opioids were administered.

MEASUREMENTS AND MAIN RESULTS

Forty-seven percent of the patients required no parenteral analgesic for 12 hours after receiving a single dose of epidural morphine, and only 10% required more than 0.1 mg/kg of parenteral morphine during this 12-hour period. For infants younger than 1 year of age, the supplemental intravenous (IV) morphine requirement was almost identical to that of the entire study population. There was no respiratory depression. All patients except those who had thoracotomies were followed on regular pediatric nursing floors.

CONCLUSIONS

Single-dose caudal epidural morphine in children is safe and effective when administered intraoperatively prior to surgery as the only opioid and coupled with appropriate monitoring, nursing education, and follow-up by the anesthesiologist. These patients can be followed on regular nursing floors with proper monitoring.