Respiratory depression after low-dose caudal morphine.

PURPOSE: To report a case of respiratory depression after a small dose of caudal morphine administered to a 15-mo-old child. CLINICAL FEATURES: A 15 mo, 9.8 kg boy underwent ureteral reimplantation with general endotracheal anaesthesia and 10 ml bupivacaine 0.25% (2.5 mg.kg-1). Ninety minutes after the bupivacaine, 0.4 mg (1 mg.ml-1, 0.4 ml, 0.04 mg.kg-1) preservative-free morphine was injected after negative aspiration. Slightly more than two hours after caudal morphine, the patient became lethargic and developed decreases in oxygen saturation (to 62%) without change in heart rate or respiratory rate. Intravenous naloxone 0.1 mg (0.01 mg.kg-1) markedly improved his level of consciousness. Racemic epinephrine was administered for treatment of coincident stridor. The patient required 11 hr continuous naloxone infusion (0.001-0.002 mg.kg-1.hr-1) in the intensive care unit. He was discharged on the second postopertive day without further complication. CONCLUSION: Respiratory depression can occur in children greater than one year of age, even when small doses of caudal morphine are used. Decreased arterial oxygen saturation and lethargy are important heralds. A normal respiratory rate despite substantial hypoxaemia argues that pulse oximetry (without supplemental oxygen where possible) has a clear advantage over impedance pneumography for electronic monitoring.

Variation in opioid use during PCA in adolescents.

The objective of this investigation was to determine if the variability in the use of opioids for pain following surgery is related to variability in blood concentration of opioids used for pain relief. We measured morphine use and morphine blood concentration in a group of otherwise healthy adolescent girls following spinal surgery. There was considerable variability in morphine use and morphine blood levels as indicated by a large range of values and a moderately large standard deviation. Morphine blood concentration correlated with morphine use. Neither morphine use nor morphine concentration correlated with pain scores. The data indicate that there is considerable variability among patients in the amount of opioid needed to achieve comfort and in the blood concentration associated with comfort. The cause of this variability does not appear to be related to metabolism of opioid, but may be related to psychological differences, differences in pain tolerance and threshold, or differences in the way patients use PCA.

Oxygen saturation in children in the postoperative period.

Some adult patients have periods of significant oxygen desaturation after surgery but, other than for immediately after surgery in the recovery room, few data are available in children. We monitored overnight paired preoperative and postoperative oxygen saturations in 19 children, and overnight postoperative saturations in 50 additional children to determine whether children have periods of desaturation in the postoperative period. The children underwent surgery usually associated with moderate to severe postoperative pain, and were treated with epidural, intravenous, or intramuscular opioids. In the group of 19 children mean (SD) preoperative oxygen saturation was 96.6% +/- 1.3%, and the mean postoperative saturation was 95.7% +/- 1.2%. The average change was 0.88% +/- 1.52%. The 95% confidence interval of the paired difference was 0.13% to 1.6%. There was no significant difference in the percent of monitored time that the patients spent with an oxygen saturation less than 95%, 90%, 85%, or 80%. In the 50 children monitored only in the postoperative period, mean (SD) saturation was 97.8% +/- 1.9%. The data show that, in contrast to some reports in adults, this group of children did not have multiple episodes of clinically significant oxygen desaturation in the postoperative period.

Postoperative pain management in children.

Postoperative pain management in children is a topic that has been neglected in the past but is currently an active field of interest and effort. Clearly, the child's cognitive understanding of and emotional response to pain are different than an adult's, and these differences make pain assessment and control more difficult. Ongoing work to develop more accurate techniques of estimating pain intensity in children may have helpful results. The effects of untreated pain in children are similar to those in adults but may have more long-term consequences in children. In the past, postoperative pain treatment in children was often inadequate, but newer techniques, such as continuous infusion of opioids, patient-controlled analgesia, epidural administration of opioids, and regional analgesia, hold promise for improved care in the future.

Patient-controlled analgesia in adolescents.

Patient-controlled analgesia (PCA) is a method of administering narcotics in which the patient activates a machine to administer a small bolus of narcotic. In the first year of PCA use in our hospital, 26 patients used PCA. We suggest a dose volume of 0.015 mg/kg/dose and a 4-hour limit of 0.25 mg/kg/4 hr, with a lock-out of 10 minutes. Patients used approximately equivalent amounts to standard parenteral narcotics, but there was a wide interpatient variability in the amount of narcotic used. No clinical respiratory depression was noted, and patients did not titrate themselves to complete analgesia. PCA is an effective means of pain control in adolescent patients.

The dose response of caudal morphine in children.

The authors compared the duration of analgesia and the frequency of side effects of three doses of caudal epidural morphine in children aged 1.2-7.9 yr. Caudal catheters were inserted in 32 children, randomly assigned to receive 0.033 mg.kg-1, 0.067 mg.kg-1, or 0.10 mg.kg-1 of preservative-free morphine for analgesia after major surgical procedures below the diaphragm. The first dose of caudal morphine was mixed with 0.25 ml.kg-1 of 1% lidocaine to confirm correct caudal catheter placement. By assessment of periodic pain scores and the time intervals between administration of caudal morphine and the recurrence of pain, the authors found that the mean (+/- SD) duration of analgesia was significantly longer after 0.10 mg.kg-1 (13.3 +/- 4.7 h) than after either 0.033 mg.kg-1 or 0.067 mg.kg-1 (10.0 +/- 3.3 and 10.4 +/- 4.2 h, respectively) (P less than 0.02). The frequency of vomiting, pruritus, and urinary retention was similar in each group. Vomiting was less common in patients who had nasogastric drainage than in patients who were fed soon after surgery (P less than 0.05). Delayed respiratory depression occurred in one child after 0.10 mg.kg-1 of caudal morphine. Caudal morphine, 0.033-0.10 mg.kg-1, provided prolonged analgesia in children. The authors recommend 0.033 mg.kg-1 of caudal morphine as an initial dose for children.

Epidural opioids in children.

Experience with spinal opioids in children is limited but is expanding. Anatomy, pharmacology, technique, and results are reviewed. Complications and side effects are described.

Assessment and management of recurrent pain in adolescence.

The pediatrician presented with an adolescent complaining of recurrent or chronic pain should assess the antecedents, sustainers and consequences of the pain syndrome. Particular attention should be paid to the developmental tasks of adolescence and the presence of psychosocial stress in the adolescent's family, school, peer relationships or community. Regardless of its etiology, effective management of recurrent or chronic pain in adolescence involves a balance of cognitive, behavioral and pharmacologic interventions.

Anesthesiology: regional anesthesia in children.

The Scientific Board of the California Medical Association presents the following inventory of items of progress in anesthesiology. Each item, in the judgement of a panel of knowledge physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, research workers, or scholars to stay abreast of these items of progress in anesthesiology that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another.The items of progress listed below were selected by the Advisory Panel to the Section on Anesthesiology of the California Medical Association and the summaries were prepared under its direction.

Caudal morphine for postoperative analgesia in children: a comparison with caudal bupivacaine and intravenous morphine.

We compared the efficacy, duration, and side effects of preservative-free morphine injected into the caudal space in children, with caudal bupivacaine and with intravenous morphine administration for relief of postoperative pain. Forty-six children, ages 1-16 yr, were randomly assigned to receive intravenous morphine (control group), caudal bupivacaine (0.25%, 1 ml/kg), or caudal morphine (0.5 mg/ml, 0.1 mg/kg). In half the patients given caudal morphine, the morphine was mixed with a dose of lidocaine adequate to produce sacral analgesia, to confirm correct caudal injection of the morphine. Caudal injections were performed at the end of surgery. Time until the first required postoperative intravenous morphine dose was recorded for each patient. The duration of analgesia was significantly greater with caudal morphine (median 12 hr, P less than 0.02) than with caudal bupivacaine (median 5 hr), and both were greater than with intravenous morphine in control patients (median 45 min). Urinary retention, pruritus, and nausea appeared with slightly greater frequency in the caudal morphine group, but no delayed respiratory depression occurred. Caudal morphine (0.5 mg/ml, 0.1 mg/kg) provided 8-24 hr of analgesia in children without a significantly greater incidence of side effects than caudal bupivacaine or intravenous morphine.

Childhood near-death experiences.

We nonselectively interviewed 11 patients aged 3 through 16 years who had survived critical illnesses, including cardiac arrests and profound comas. Any memory of a time they were unconscious was considered to be a near-death experience (NDE) and was recorded. Seven of these children had memories that included being out of the physical body (six patients), entering darkness (five patients), being in a tunnel (four patients), and deciding to return to the body (three patients). We also interviewed 29 age-matched survivors of illnesses that required intubation, narcotics, benzodiazepines, and admission to an intensive care unit. None of them had any memories of the time they were unconscious. In our study population, NDEs were clearly associated with surviving a critical illness. The elements of NDEs reported are similar to those previously described in adults. No children described elements of depersonalization as part of their NDEs. A core NDE, triggered by the process of dying or resuscitation efforts, may be a natural developmental experience. We present a neurophysiologic hypothesis as to the cause of NDEs.

Oxygen and resolution of lung injury.

We investigated the effects of varying inspired oxygen concentrations on the resolution of oleic acid-induced lung injury in rabbits. Rabbits were injected intravenously with oleic acid and maintained in room air, or exposed to 60, 70, or 80% oxygen for periods of 7 or 10 days. Oleic acid caused hemorrhagic pulmonary edema with hypoxemia. Hypoxemia was more profound in the oxygen-treated animals, a difference that was significant after 7 days' exposure to 60 and 70% oxygen, and after 4 days to 80% oxygen. Mortality was increased in the animals maintained in 80% oxygen. The data suggest that environmental oxygen concentrations greater than 60% interfere with the return to normal lung function following oleic acid injury in rabbits. The hypoxemia may be due to either mismatching of ventilation and perfusion or to a diffusion block resulting from the increased septal width. There was no evidence of massive pulmonary edema as a cause of the hypoxemia. It was not possible to distinguish between injury primarily caused by oxygen and its interference with the healing process.

Laryngeal cleft: report of eight patients and a review of the literature.

Eight cases of laryngeal cleft are presented and the literature on this topic is reviewed. Patients most frequently present with stridor, respiratory distress, or a history of choking while feeding. A number of cases are found at autopsy or surgery. Laryngeal cleft frequently is found associated nonspecifically with tracheoesophageal fistula, cleft lip and cleft palate, and congenital heart defects. Laryngeal cleft may be a component manifestation of several syndromes, eg, the G syndrome, and the Pallister-Hall syndrome of congenital hypothalamic hamartoblastoma, hypopituitarism, imperforate anus, and postaxial polydactyly. Surgical treatment is successful in more than 50% of the reported cases, depending on the extent of the cleft. Cleft larynx is most likely a developmental field defect, occurring coincidentally with separation of larynx and esophagus and closure of the larynx.

Isolated deafness following recovery from neurologic injury and adult respiratory distress syndrome. A sequela of intercurrent aminoglycoside and diuretic use.

We report two children who survived neurologic injury (near-drowning and Reye's syndrome) and adult respiratory distress syndrome and who required prolonged ventilatory support. Follow-up examination in both children showed steady neurologic recovery, but five months following discharge from their acute illness, profound hearing loss was diagnosed in both children. A review of the literature is reported and the hypothesis that combined aminoglycoside antibiotic and loop diuretic therapy caused the hearing loss is presented. Recommendation is made for audiologic assessment within six months of recovery from critical illness of pediatric patients in whom therapy has included loop diuretic and aminoglycoside antibiotic therapy.

Coma scale for use in brain-injured children.

The association between admission coma score and eventual outcome was assessed using a coma scale developed for children with a variety of central nervous system injuries. As opposed to the Glasgow coma scale, this scale does not demand assessment of verbalization, and thus can be applied to the preverbal or previously intubated child. Cortical function is graded from 6 (purposeful, spontaneous movements) to 0 (flaccid), and brainstem function is graded from 3 (intact) to 0 (absent and apneic). Maximum total score is 9. In 91 children treated for intracranial hypertension, the association was moderately good. The scale was better in predicting the outcome of patients with hypoxic encephalopathy and head trauma than that of patients with Reye's syndrome, meningitis, or encephalitis. No child with a score of less than 3 survived in spite of intensive therapy. Most of these children were flaccid with depressed or absent brainstem reflexes. No child with flaccidity on admission survived.

Morphine infusion after pediatric cardiac surgery.

After cardiac surgery, 44 children received a continuous iv infusion of morphine sulfate at 10 to 30 micrograms/kg X h. During weaning from assisted ventilation and during spontaneous ventilation serum morphine levels less than 30 ng/ml were not associated with elevated PaCO2. Five extubated patients breathed spontaneously, and 35 patients were weaned from assisted to spontaneous ventilation with normal PaCO2 while receiving morphine by infusion, indicating that morphine did not interfere with spontaneous ventilation. In 12 older children who gave verbal pain scores, pain was relieved at serum morphine levels above 12 ng/ml.

Profound shock following intervention for chronic untreated stool retention. A case report.

Chronic stool retention with soiling is a common and distressing condition in children. Diagnosis and treatment generally involve both medical and psychological aspects. This case addresses a potentially life-threatening complication of shock occurring during treatment of chronic stool retention with castor oil, and also explores the psychosocial factors felt to be contributory.