Electroencephalographic markers of brain development during sevoflurane anaesthesia in children up to 3 years old.

BACKGROUND: General anaesthetics generate spatially defined brain oscillations in the EEG that relate fundamentally to neural-circuit architecture. Few studies detailing the neural-circuit activity of general anaesthesia in children have been described. The study aim was to identify age-related changes in EEG characteristics that mirror different stages of early human brain development during sevoflurane anaesthesia. METHODS: Multichannel EEG recordings were performed in 91 children aged 0-3 yr undergoing elective surgery. We mapped spatial power and coherence over the frontal, parietal, temporal, and occipital cortices during maintenance anaesthesia. RESULTS: During sevoflurane exposure: (i) slow-delta (0.1-4 Hz) oscillations were present in all ages, (ii) theta (4-8 Hz) and alpha (8-12 Hz) oscillations emerge by ∼4 months, (iii) alpha oscillations increased in power from 4 to 10 months, (iv) frontal alpha-oscillation predominance emerged at ∼6 months, (v) frontal slow oscillations were coherent from birth until 6 months, and (vi) frontal alpha oscillations became coherent ∼10 months and persisted in older ages. CONCLUSIONS: Key developmental milestones in the maturation of the thalamo-cortical circuitry likely generate changes in EEG patterns in infants undergoing sevoflurane general anaesthesia. Characterisation of anaesthesia-induced EEG oscillations in children demonstrates the importance of developing age-dependent strategies to monitor properly the brain states of children receiving general anaesthesia. These data have the potential to guide future studies investigating neurodevelopmental pathologies involving altered excitatory-inhibitory balance, such as epilepsy or Rett syndrome.

Periaqueductal gray neuroplasticity following chronic morphine varies with age: role of oxidative stress.

The development of tolerance to the antinociceptive effects of morphine has been associated with networks within ventrolateral periaqueductal gray (vlPAG) and separately, nitric oxide signaling. Furthermore, it is known that the mechanisms that underlie tolerance differ with age. In this study, we used a rat model of antinociceptive tolerance to morphine at two ages, postnatal day (PD) 7 and adult, to determine if changes in the vlPAG related to nitric oxide signaling produced by chronic morphine exposure were age-dependent. Three pharmacological groups were analyzed: control, acute morphine, and chronic morphine group. Either morphine (10mg/kg) or equal volume of normal saline was given subcutaneously twice daily for 6½ days. Animals were analyzed for morphine dose-response using Hot Plate test. The expression of several genes associated with nitric oxide metabolism was evaluated using rtPCR. In addition, the effect of morphine exposure on immunohistochemistry for Fos, and nNOS as well as nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) reaction at the vlPAG were measured. In both age groups acute morphine activated Fos in the vlPAG, and this effect was attenuated by chronic morphine, specifically in the vlPAG at the level of the laterodorsal tegmental nucleus (LDTg). In adults, but not PD7 rats, chronic morphine administration was associated with activation of nitric oxide function. In contrast, changes in the gene expression of PD7 rats suggested superoxide and peroxide metabolisms may be engaged. These data indicate that there is supraspinal neuroplasticity following morphine administration as early as PD7. Furthermore, oxidative stress pathways associated with chronic morphine exposure appear age-specific.

Stable plasma concentrations of unbound ropivacaine during postoperative epidural infusion for 24-72 hours in children.

BACKGROUND AND OBJECTIVES: The aim of this open, non-controlled, multi-centre study was to evaluate the pharmacokinetics and safety of a 24-72 h continuous epidural ropivacaine infusion in children aged 1-9 yr. METHODS: After induction of general anaesthesia, 29 ASA I-II children, scheduled for major surgery in dermatomes below T10 had lumbar epidural catheters placed. A bolus of ropivacaine, 2 mg kg(-1), was given over 4 min, followed immediately by an infusion of 2 mg mL(-1) ropivacaine 0.4 mg kg(-1) h(-1) for the next 24-72 h. RESULTS: Plasma concentrations of total ropivacaine (mean 0.83 and 1.06 mg L(-1) at 16-31 and 59-72 h, respectively) and alpha1-acid-glucoprotein (mean 13 and 25 micromol L(-1) at baseline and 59-72 h) increased over the course of the infusion. Plasma concentrations of unbound ropivacaine were stable throughout the epidural infusion (mean 0.021 range 0.011-0.068 and mean 0.016 range 0.009-0.023 mg L(-1) at 16-31 and 59-72 h, respectively) and were well below threshold levels associated with central nervous system toxicity in adults (0.35 mg L(-1)). Apparent unbound clearance (mean 346, range 86-555 mL min(-1) kg(-1)) showed no age-dependency. No signs of systemic toxicity or cardiovascular effects were observed. All patients received additional analgesics with morphine. CONCLUSION: Following a 24-72 h epidural infusion of ropivacaine 0.4 mg kg(-1) h(-1) in 1-9-yr-old children, the plasma concentrations of unbound ropivacaine were stable over time with no age-dependency.

Prolonged local myometrial blockade prevents preterm labor after fetal surgery in a leporine model.

BACKGROUND/PURPOSE: Postoperative premature labor remains the foremost limiting factor to the development of fetal surgery. Most attempts at controlling this complication have involved the use of drugs delivered systemically to the mother. This study assessed the effects of prolonged local anesthetic blockade of the myometrium on preterm delivery after open fetal surgery. METHODS: Eighteen New Zealand rabbits at 23 days' gestation (term, 31 to 33 days) were divided in three groups. In group I (n = 6), the most proximal fetuses of both uterine horns were submitted to open amputation of a forelimb; in a few animals, one of the uterine horns was empty, hence, only one fetus was manipulated. In groups II (n = 5) and III (n = 7), an identical surgical procedure was performed. In group II, immediately before hysterotomy, the myometrium was injected with 0.5 mL of 0.5% bupivacaine along the incision line. In group III, only saline was injected. In group II, before uterine closure, the incised area of the myometrium was injected with 1.5 mL of a novel suspension of biodegradable polylactic-co-glycolic acid microspheres loaded with 75% w/w bupivacaine and 0.05% w/w dexamethasone. This suspension previously has been shown to provide peripheral nerve blockade for approximately 5 days. In group III, microspheres without any drug were injected. RESULTS: Abortion rates were significantly different among the groups: 83.3% (five of six) for the does in group I, zero in group II, and 71.4% (five of seven) in group III (P < .05). The absence of abortions observed in group II occurred despite the fact that the fetal mortality rate was significantly higher in this group (87.5%, seven of eight fetuses) than in groups I (0) and III (33.3%, 4 of 12 fetuses, P < .05). CONCLUSIONS: Prolonged local blockade of the myometrium with bupivacaine inhibits preterm labor after fetal surgery in rabbits. The high fetal mortality rate observed in this study may be caused by "transplacental" transfer of the local anesthetic to the fetus. Notably, the abortifacient effect of a dead fetus was completely suppressed by the local blockade. Studies using microspheres with local anesthetics that do not cross the placenta, in animal models with longer gestational periods, are warranted.

Prolonged intercostal nerve blockade in sheep using controlled-release of bupivacaine and dexamethasone from polymer microspheres.

BACKGROUND: Previous work from the authors' group characterized a prolonged percutaneous blockade of the sciatic nerve in rats using bupivacaine-dexamethasone microspheres. The goals of the current study are to examine the (1) efficacy of bupivacaine microspheres with and without dexamethasone for intercostal blockade in sheep; (2) scaling of dose and duration with a 100-fold increase in body size from rats to sheep; (3) local toxicity and adverse systemic reactions to bupivacaine microspheres with and without dexamethasone. METHODS: Intercostal blocks were performed percutaneously in sedated sheep. Sensory blockade was measured at repeated time points by absent flinch response to skin pinch. Plasma bupivacaine concentrations were measured using high performance liquid chromatography. Chest wall specimens were examined by light microscopy. RESULTS: The duration of intercostal blockade increased with bupivacaine dose for animals receiving from 8 to 80 mg/kg of microspheres with and without dexamethasone. At each dose, microspheres containing dexamethasone had a longer duration of block than microspheres without dexamethasone. From 8 to 80 mg/kg, the mean duration of block with bupivacaine-dexamethasone microspheres increased from 4 to 13 days. Plasma concentrations of bupivacaine remained 10-fold below the convulsive EC50 concentration for sheep. Chest wall histology showed a significant granulomatous reaction around bupivacaine microspheres but not around bupivacaine-dexamethasone microspheres. CONCLUSIONS: A single administration of bupivacaine-dexamethasone microspheres produces an effective chest wall analgesia of several days' duration. This may prove useful clinically for thoracic surgery or trauma.

Patient-controlled analgesia for mucositis pain in children: a three-period crossover study comparing morphine and hydromorphone.

OBJECTIVES: (1) To test the safety and efficacy of a clinical protocol for administering opioid by using patient-controlled analgesia (PCA) for the management of mucositis pain in children after bone marrow transplantation, (2) to compare the efficacy, side-effect profile, and potency ratio of morphine with those of hydromorphone by using PCA as the method of opioid administration, and (3) to obtain pharmacokinetic data on hydromorphone and morphine in this population of children. METHODS: In this double-blind, three-period crossover study, patients were randomly assigned to receive either morphine (group 1) or hydromorphone (group 2) initially by means of PCA on days 1, 2, and 3 (period 1), to be followed on days 4, 5, and 6 (period 2) with the alternative opioid, followed by the opioid used at the commencement of the study on days 7, 8, and 9 (period 3). A clinical protocol for calculating the PCA commencement opioid dose and subsequent opioid-dose escalation was tested by measures of safety and efficacy. Measures of pain intensity and opioid side effects were made during the three periods. On the last study day (day 10), patients received a continuous infusion of opioid derived from the previous 24-hour PCA opioid requirement, and blood specimens were collected and stored for subsequent opioid analysis. RESULTS: Ten patients were enrolled in this study. Rapid escalation in opioid requirement commonly occurred at the commencement of PCA, followed by a variable plateau phase and then deescalation of opioid requirement after mucositis resolution. The measures demonstrated the safety and efficacy of the clinical protocol. In the concentrations used, there was no statistical difference between the mean daily pain, sedation, nausea and vomiting, and pruritus scores for both opioids (Friedman test). The analysis of variance of the log-total opioid doses per patient during periods 1, 2, and 3 indicated that patients used 27% more hydromorphone than expected from its presumed 7:1 ratio relative to morphine potency used in the PCA infusions. The mean plasma hydromorphone concentration was 4.7 ng/ml (range, 1.9 to 8.9 ng/ml), and the mean clearance was 51.7 ml/min per kilogram of body weight (range, 28.6 to 98.2 ml/min per kilogram). The mean plasma morphine, morphine-6-glucuronide, and morphine-3-glucuronide concentrations were 40.0 ng/ml (range, 15 to 62.5), 168.2 ng/ml (range, 54.4 to 231.9), and 391.0 ng/ml (range, 149.4 to 921.7), respectively. The mean morphine clearance was 34.3 ml/min per kilogram of body weight (range, 19.3 to 58.3). The mean molar ratios of morphine-6-glucuronide/morphine, morphine-3-glucoronide/morphine, and morphine-3-glucuronide/morphine-6-glucuronide were 2.48 (range, 1.4 to 3.3), 5.82 (range, 3.4 to 9.1), and 2.46 (range, 1.1 to 3.3), respectively. CONCLUSIONS: The safety and efficacy of a clinical protocol for the administration of opioids by means of PCA for mucositis pain after bone marrow transplantation was demonstrated. In this small study, hydromorphone was not superior to morphine in terms of analgesia or the side-effect profile: a larger study would be needed to show a difference. The clearances of hydromorphone and morphine in the children studied were generally greater than those previously recorded, but this finding may be related to disease or treatment variables. Apart from clearance, the morphine pharmacokinetics in the study population were similar to those previously recorded. Hydromorphone may be less potent in this population of children than indicated by adult equipotency tables.

Halothane and cardiac autonomic control in infants: assessment with quantitative respiratory sinus arrhythmia.

In comparison to adults, infants undergoing halothane anesthesia have an increased incidence of clinically significant episodes of bradycardia, hypotension, and cardiac arrest. To examine potential cardiac autonomic regulatory mechanisms that may account for these observations, the relationship between respiratory activity and short-term variations of heart rate was quantified in 10 healthy term nonpremedicated infants (28.4 +/- 0.6 wk old) undergoing elective surgery with halothane and low caudal anesthesia. Quantitative respiratory activity, heart rate, and cuff blood pressure data were obtained during the preoperative awake period, and at three depths of halothane--1, 1.3, and 2.0 mean alveolar concentration (MAC). Time and frequency domain analyses were performed on two 2.2-min epochs of data from each condition to yield mean values, spectral measures of low (0.02-0.15 Hz) and high (0.15-0.80 Hz) frequency power (LF and HF), and the LF/HF ratio. The sympathetic (As) and parasympathetic (Ap) components of respiratory sinus arrhythmia were quantified using the transfer relations between respiration and heart rate to derive gain factors Ax and Ap, respectively. Mean heart rate, blood pressure, and respiratory activity all decreased with halothane exposure (p < 0.01), but did not differ by halothane dose. Similarly, LF, HF, LF/HF, and respiratory powers all decreased with halothane, but not between doses. When the effects of respiratory activity on heart rate were accounted for, As decreased at 1.3 and 2.0 MAC only, but Ap remained unchanged. Decreased LF and HF power suggests that halothane altered both sympathetic and parasympathetic heart rate control; however, when the ratio between LF and HF and the quantitative effects of respiration are accounted for, halothane appears to cause a reduction in respiratory related sympathetic heart rate control, without a significant change in parasympathetic control.

Chronic pain in cystic fibrosis.

OBJECTIVE: The objective of this study was to examine the incidence and therapy of chronic pain in a group of older patients with cystic fibrosis (CF). PATIENTS: We identified two groups of patients followed at the CF Center at Children's Hospital (Boston); the first group consisted of all patients above the age of 5 years who died between 1984 and 1993, and the second was a cohort of 23 additional CF patients who had been referred to the Pain Treatment Service. DESIGN: Medical charts were reviewed for the etiology and therapy of all pain episodes requiring medical intervention. RESULTS: The incidence of chronic pain in this population increased sharply in the last 6 months of life. Headaches (55% of patients) and chest pain (65%) were frequently reported, although back pain (19%), abdominal pain (19%), and limb pain (16%) were also reported. In patients with headache, the main etiologies were hypercarbia or hypoxia, migraine, and sinusitis. The majority of chest pain was musculoskeletal, with pleuritis, pneumothorax, and rib fracture also reported as the cause of chest pain. INTERVENTIONS: A variety of nonpharmacological and pharmacological therapies were reported. Forty-one patients (53%) had pain severe enough to require opioid treatment, and 10 patients (13%) received opioids for more than 3 months. In eight patients with more severe pain, regional analgesia was found to be particularly effective. CONCLUSIONS: Chronic pain is a common problem in CF, particularly as the patient population ages. When administered with caution, opioids have proven to be effective and safe in this population; regional anesthesia can be used to preserve pulmonary toilet while adequately treating severe pain.

Control of severe pain in children with terminal malignancy.

OBJECTIVE: To identify the characteristics of the subset of children with malignancy in whom massive opioid infusions are needed during the terminal phase. DESIGN: Retrospective review of the records of the 199 patients who died of malignancy after treatment at Children's Hospital, Boston, from March 1989 to July 1993, identifying characteristics of patients who required massive opioid infusions (operationally defined as infusion of > 3 mg/kg per hour of morphine dose equivalent) during the terminal phase. RESULTS: Twelve patients (6%) required massive opioid infusions, and eight of these patients required extraordinary measures (epidural or subarachnoid infusion and/or sedation) to achieve adequate analgesia. The duration of epidural or subarachnoid infusions in three patients ranged from 3 to 9 days, and minimal complications occurred. The duration of sedation ranged from 1 to 15 days. Maximal intravenous opioid dosing ranged from 3.8 to 518 mg/kg per hour of morphine equivalent. The maximal infusion rate (exceeding all previous published reports) occurred in an infant with an isolated metastasis in the periaqueductal gray matter, a brain-stem site linked to mediating analgesia and defense reactions. The need for massive opioid dosing in 11 of 12 patients was associated with tumor spread to the spinal nerve roots, nerve plexus, large peripheral nerve, or spinal cord compression. CONCLUSIONS: Standard dosing of opioids adequately treats most cancer pain in children; however, a significant group requires more extensive management. These problems occur more commonly among patients with solid tumors metastatic to spine and major nerves.

A double-blind evaluation of ketorolac tromethamine versus acetaminophen in pediatric tonsillectomy: analgesia and bleeding.

The study was designed to compare intravenous ketorolac to rectal acetaminophen for analgesia and bleeding in pediatric patients undergoing tonsillectomy. We studied 50 patients, aged 2-15 yr undergoing tonsillectomy with or without adenoidectomy. In a randomized, prospective double-blind fashion, patients were assigned to receive either ketorolac (1 mg/kg) or rectal acetaminophen (35 mg/kg). Bleeding was evaluated by measuring intraoperative blood loss and noting extra measures required to obtain hemostasis. Bleeding times were also measured before and during surgery. Pain was evaluated using a standard objective pain score for the first 3 h. Persistent pain was treated with morphine, acetaminophen, and codeine and recorded for 24 h. Blood for determination of acetaminophen levels was drawn at 20 and 40 min after the administration of study drugs. Pain scores were not significantly different between the ketorolac and acetaminophen groups. The majority of patients in both groups required additional opioid in the postoperative period. Acetaminophen levels were all less than the therapeutic range. Intraoperative bleeding times were normal in all patients, but blood loss was significantly higher in the ketorolac group (2.67 mL/kg) compared to the acetaminophen group (1.44 mL/kg), P = 0.025. Significantly more measures to achieve hemostasis were required in the ketorolac group (P = 0.012). We conclude that ketorolac is no more effective than high-dose rectal acetaminophen for analgesia in the patient undergoing tonsillectomy. Hemostasis during tonsillectomy was significantly more difficult to achieve in patients receiving ketorolac.

The risk of infection from epidural analgesia in children: a review of 1620 cases.

We reviewed cases to determine whether suspected or confirmed epidural infection was associated with epidural analgesia for 1620 infants, children, and adolescents treated over a 6-yr period at Children's Hospital, Boston. Postoperative patients (1458/1620) received epidural infusions for a median of 2 days (range, 0-8 days). No postoperative patient had an epidural abscess. One 10-yr-old with terminal malignancy received thoracic epidural analgesia via two successive catheters over a 4-wk period. She had Candida colonization of the epidural space along with necrotic epidural tumor. A second oncology patient and two patients with reflex sympathetic dystrophy were evaluated for epidural abscess, but none was found. We conclude that the risk of epidural infection is quite low in pediatric postoperative patients receiving short-term catheterization. Use of prolonged epidural analgesia in the management of chronic pain in children requires careful monitoring of warning signs of infection.

Dextroamphetamine or methylphenidate as adjuvants to opioid analgesia for adolescents with cancer.

The doses of opioid analgesics required to control pain in patients with cancer may result in somnolence and reduced interaction with family members. Psychostimulants such as dextroamphetamine (DA, Dexedrine) or methylphenidate (MP, Ritalin) have been used in adults to counteract the sedation of opioid analgesia. We retrospectively reviewed our experience using these agents at Children's Hospital. Eleven patients (age 12-20 years) received DA or MP, and decreased somnolence or improved interaction was noted in five patients. Adverse effects potentially related to DA or MP were noted in two patients, none of which resulted in discontinuance of the stimulant. Further prospective, controlled studies are needed to assess the safety and efficacy of DA and MP in counteracting the sedation of opioid analgesia in children and adolescents.

Chronic exposure to lidocaine does not alter flux through sodium channels in cultured neuronal cells.

BACKGROUND AND OBJECTIVES: Although tachyphylaxis to local anesthetics has been reported in the clinical literature for more than two decades, the molecular mechanism(s) remain unknown. The authors described an attempt to create an in vitro model for tachyphylaxis to local anesthetics using cultured neuronal cells. METHODS: Murine neuroblastoma cells (N1E115) and rat pheochromocytoma cells (PC-12) were grown in the presence or absence of lidocaine or tetrodotoxin for between 1 and 14 days. Thereafter, the authors tested flux through sodium channels by measuring total and tetrodotoxin-sensitive flux of 14C-labeled guanidinium (a ligand for the sodium channel) into the cells using the technique of Jacques et al. RESULTS: Chronic lidocaine or tetrodotoxin treatment caused no change relative to control cells in total or tetrodotoxin-sensitive guanidinium flux, or in the subsequent ability of lidocaine in the flux assay mixture to inhibit guanidinium flux. CONCLUSIONS: The authors concluded that chronic lidocaine or tetrodotoxin application did not produce changes in stimulated sodium channel activity or subsequent lidocaine susceptibility in this model. To the extent that this model simulated the clinical situation, mechanisms other than up-regulation of sodium channel number or maximal stimulated flux per channel may have been responsible for producing tachyphylaxis.

Continuous caudal anesthesia for inguinal hernia repair in former preterm infants.

STUDY OBJECTIVE: To determine the feasibility of continuous caudal anesthesia with 2-chloroprocaine in conscious former preterm infants undergoing inguinal hernia repair. DESIGN: Prospective study. SETTING: University-affiliated children's hospital. PATIENTS: Ten former preterm infants, ASA physical status II and III, who were 35 to 49.5 weeks postconceptional age at the time of surgery. INTERVENTIONS: Caudal anesthesia was administered via an indwelling catheter using a loading dose of 1 ml/kg (30 mg/kg) of 3% 2-chloroprocaine, followed by incremental doses of 0.3 ml/kg (9 mg/kg) to achieve a level of T4 to T2. The block was maintained by a minimum infusion rate of 30 mg/kg/hr (1 ml/kg/hr) of the same local anesthetic solution. MEASUREMENTS AND MAIN RESULTS: The mean cumulative dose of 2-chloroprocaine was 2.8 +/- 1.0 ml/kg/hr (84 +/- 30 mg/kg/hr) infused over a mean duration of 95 +/- 35 minutes. Serum cholinesterase concentration and plasma 2-chloroprocaine concentration were measured in five infants. CONCLUSIONS: Three percent 2-chloroprocaine can be used effectively for continuous caudal anesthesia in conscious, former preterm infants for inguinal hernia and penoscrotal surgical procedures lasting 85 to 170 minutes.

Reflex sympathetic dystrophy in children. Clinical characteristics and follow-up of seventy patients.

We report on the experience with our first seventy patients who had reflex sympathetic dystrophy and were less than eighteen years old (average age, 12.5 years). In our series, the patients were predominantly girls (male to female ratio, 11:59) and the lower extremity was involved most often (sixty-one of the seventy patients). The average time from the initial injury to the diagnosis was one year, which indicates that the syndrome remains under-recognized in patients in this age-group. Conservative treatment with physical therapy, transcutaneous electrical nerve stimulation, psychological therapies including cognitive-behavioral management and relaxation training, and tricyclic anti-depressants was effective in improving the average scores for pain and function for forty patients. Sympathetic blocks were helpful for twenty-eight of thirty-seven patients. Thirty-eight of the seventy patients in the series continued to have some degree of residual pain and dysfunction. Reflex sympathetic dystrophy in children differs in presentation and clinical course from the syndrome in adults. It is best treated in a multidisciplinary fashion.

Midazolam for conscious sedation during pediatric oncology procedures: safety and recovery parameters.

Multiple bone marrow aspirations or biopsies and lumbar punctures are a necessary part of the diagnosis and treatment of many pediatric cancer patients. Pharmacologic sedation may decrease the distress associated with these procedures. Midazolam (MDZ, Versed) is a water-soluble, rapid-onset, short-duration benzodiazepine that has not been studied widely in children. We prospectively evaluated safety and recovery parameters for intravenous MDZ used for conscious sedation by oncologists (without an anesthesiologist in attendance) for 70 procedures (bone marrow aspirations, lumbar punctures, or bone marrow aspirations plus lumbar punctures) in 24 ambulatory pediatric cancer patients, aged 1.5 to 15.5 years. MDZ was used alone or in combination with morphine or fentanyl. Respiratory rate, oxygen saturation, blood pressure, and heart rate were monitored. Sedation, anxiolysis, and recovery were assessed with a behavior score and a modified recovery room discharge score. Restraint was not required in 45% of the procedures. In no case was a respiratory rate less than 12 observed. In nine procedures (13%), an oxygen saturation less than or equal to 90 occurred, all within 10 minutes after the last dose of MDZ. Ten procedures (14%) required verbal stimulation to take deeper breaths. Two patients did not respond immediately to verbal stimulation and received face-mask oxygen. Hypoxemia was not correlated with opioid use. Hypoxemia appears to be related to total MDZ dose and may occur with normal respiratory rates; all cases resolved with verbal stimulation or face-mask oxygen without specific airway maneuvers or assisted ventilation. Heart rate and blood pressure remained stable in all 70 procedures.(ABSTRACT TRUNCATED AT 250 WORDS)

Continuous subarachnoid analgesia in two adolescents with severe scoliosis and impaired pulmonary function.

We report postoperative pain management of two adolescents after upper abdominal procedures, one with Hurler-Scheie syndrome and a second with Duchenne muscular dystrophy, and both had progressive spinal scoliosis with poor pulmonary function. A combined technique of subarachnoid and general anesthesia was used during surgery. Postoperative administration of small intermittent doses of subarachnoid morphine produced profound analgesia, which eliminated the need for systemic opioids, restored preoperative arterial oxygenation within 48 hours after the operation, and expedited postoperative recovery.

Comparison of morphine and methadone for prevention of postoperative pain in 3- to 7-year-old children.

A randomized, double-blind, prospective study was performed to determine the effects of perioperative administration of morphine or methadone on postoperative analgesic requirements and pain scores in 35 children aged 3 to 7 years undergoing major surgery. After a standardized induction of anesthesia, methadone or morphine, 0.2 mg/kg, was blindly administered, and supplemental doses were titrated to achieve comfort in the recovery room. Pain was assessed during the next 36 hours with a combination of validated behavioral and self-report measures. Patients in the methadone group required fewer supplemental opioid analgesic drugs during the next 36 hours, and reported lower pain scores. No patient had prolonged emergence from anesthesia, and no patient required naloxone or postoperative ventilatory assistance. No major adverse events occurred. We conclude that perioperative intravenous administration of methadone is an effective, inexpensive, and technologically simple means for providing prolonged analgesia for children after surgery.

Patient-controlled analgesia in children and adolescents: a randomized, prospective comparison with intramuscular administration of morphine for postoperative analgesia.

A randomized, prospective trial of patient-controlled analgesia (PCA), that is, a method of analgesia administration involving a computer-driven pump activated by patients to receive small doses within defined limits was performed in 82 children and adolescents after major orthopedic surgery to compare (1) intramuscularly administered morphine, (2) PCA morphine and (3) PCA morphine with a low-dose continuous morphine infusion (PCA-plus). Patients receiving PCA and PCA-plus had lower pain scores and greater satisfaction than patients receiving intramuscularly administered morphine. The three groups used equal amounts of morphine and most measures of recovery were identical in the groups. In particular, PCA and PCA-plus did not increase the incidence of opioid-related complications, and patients receiving PCA-plus were less sedated than patients receiving intramuscular therapy. We conclude that PCA and PCA-plus are safe and effective methods of pain relief in children and adolescents after orthopedic surgery, are better accepted than intramuscular injections, and do not increase perioperative morbidity.