The effects of cardiopulmonary bypass on remifentanil kinetics in children undergoing atrial septal defect repair.

UNLABELLED: Cardiopulmonary bypass (CPB) can greatly influence the pharmacokinetics of opioids. This study investigated the pharmacokinetic profile of remifentanil in 12 pediatric patients undergoing CPB for repair of an atrial septal defect. All patients received remifentanil (5 microg/kg) over 1 min into a peripheral vein both before the onset of CPB and after the discontinuation of CPB. Arterial blood samples were obtained at defined time periods, and remifentanil concentration was determined using high-performance liquid chromatography ultraviolet detection. The pharmacokinetic profiles both before and after bypass were determined in all 12 patients. There was no change in the volume of distribution at steady state, the volume of the central compartment, or the alpha- and beta-elimination half-life. Although the clearance values increased 20% in the postbypass period (from 38.7 +/- 9.6 to 46.8 +/- 14 mL x kg(-1) x min(-1), there was no meaningful change in the coefficient of variation (from 25% to 30%). IMPLICATIONS: After cardiopulmonary bypass the clearance of remifentanil increases in children. However, the relative lack of change in the coefficient of variation suggests that remifentanil should be a predictable drug in the postcardiopulmonary bypass period.

A randomized multicenter study of remifentanil compared with alfentanil, isoflurane, or propofol in anesthetized pediatric patients undergoing elective strabismus surgery.

Remifentanil hydrochloride is a new, ultrashort-acting opioid metabolized by nonspecific plasma and tissue esterases. We conducted this multicenter study to examine the hemodynamic response and recovery profile of premedicated children undergoing strabismus repair who were randomly assigned to receive one of four treatment drugs (remifentanil, alfentanil, isoflurane, or propofol) along with nitrous oxide and oxygen for maintenance of anesthesia. Induction of anesthesia was by nitrous oxide, oxygen, and halothane or nitrous oxide, oxygen, and propofol. Anesthesia was then maintained with remifentanil 1.0 microgram/kg over 30-60 s, followed by a constant infusion of 1.0 microgram.kg-1.min-1, alfentanil 100 micrograms/kg bolus followed by a constant infusion of 2.5 micrograms.kg-1.min-1, propofol 2.5 mg/kg bolus followed by a constant infusion of 200 micrograms.kg-1.min-1, or isoflurane 1.0 minimum alveolar anesthetic concentration. The infusions of the anesthetics and the administration of the inhaled gases were adjusted clinically by predetermined protocols. Elapsed time intervals from the end of surgery to the time the patients were tracheally extubated and displayed purposeful movement, as well as the time the patients met the postanesthesia care unit (PACU) and hospital discharge times, were recorded. Heart rate and systolic and diastolic blood pressure were measured at fixed intervals. In addition, cardiovascular side effects (bradycardia, hypotension, and hypertension) as well as vomiting, pruritus, agitation, and postoperative hypoxemia were also noted. There were no significant differences in patient demographics among the treatment groups. There was no difference in the early recovery variables (times to extubation and purposeful movement) or the times to PACU and hospital discharge among groups. There were significant differences in side effects among the groups. Patients who received remifentanil had higher PACU objective pain-discomfort scores than those who received alfentanil and propofol. Patients anesthetized with alfentanil had a greater incidence in the use of naloxone and a greater incidence of postoperative hypoxemia compared with those anesthetized with remifentanil. The incidence of postoperative hypoxemia was the same for remifentanil, propofol, and isoflurane groups. There were no significant differences in the incidence of emesis among the four groups, and all four groups had similar hemodynamic profiles. We conclude that remifentanil appears to be an effective drug for anesthesia. Its hemodynamic and recovery profile appear similar to other comparable drugs. Based on previous pharmacokinetic studies, the 1.0 microgram.kg-1.min-1 infusion may be twice the 50% effective dose observed in adults. In this study, the relative "overdose" of remifentanil was well tolerated and did not prolong recovery.

Effect of antiemetic therapy on recovery and hospital discharge time. A double-blind assessment of ondansetron, droperidol, and placebo in pediatric patients undergoing ambulatory surgery.

BACKGROUND: Postoperative nausea and vomiting continue to be a significant problem for pediatric ambulatory surgery patients. Although ondansetron has been demonstrated to be effective in the prophylactic treatment of postoperative nausea and vomiting (surrogate end point) no one has demonstrated a benefit of antiemetic therapy on patient recovery, postanesthesia care unit length of stay, and hospital length of stay (nonsurrogate end points). In a double-blind manner, the effects of ondansetron, droperidol, and placebo on the incidence of emesis, postanesthesia care unit stay, and hospital discharge time were evaluated in children undergoing dental surgery. METHODS: The subjects were 102 children aged 2-8 years undergoing complete dental restoration. All patients received midazolam before undergoing inhalation induction of anesthesia with N2O/O2 and halothane. Anesthesia was maintained with N2O/O2 and alfentanil. Patients were then randomized to receive ondansetron (0.1 mg/kg), droperidol (75 micrograms/kg), or placebo (normal saline) in a double-blind fashion. At the conclusion of the anesthesia, a trained nurse observer assessed patient recovery and recorded the time patients met specified criteria for postanesthesia care unit and hospital discharge as well as episodes of emesis in the hospital and at home during the first 24 hr after surgery. RESULTS: Ninety-five patients completed the study. The three antiemetic groups were similar with respect to age, weight, length of surgery, dose of alfentanil, and route of preanesthetic medication. The 24-hr incidence of emesis was significantly less with ondansetron (9%) than with placebo (35%) or droperidol (32%). Ondansetron-treated patients had significantly shorter hospital stays than droperidol-treated patients, but recovery parameters were similar between the ondansetron- and placebo-treated patients. CONCLUSIONS: Ondansetron is an effective prophylactic antiemetic agent for children undergoing dental surgery. Compared with droperidol, ondansetron decreases the length of hospital stay, but compared to placebo, there were no differences in the patient recovery parameters.

Unintentional perineal injury in prepubescent girls: a multicenter, prospective report of 56 girls.

OBJECTIVE: To determine the pattern of perineal injuries and frequency of hymenal involvement resulting from unintentional trauma in prepubescent girls. DESIGN: Prospective, multicenter. Observation by skilled observers. Determination of the circumstance and physical pattern of injury, with specific attention to the hymen. SETTING: Children's emergency department or acute care clinic. PATIENTS: Tanner stage 1 girls presenting with acute perineal injury. Criteria for unintentional injury: observation of the event or knowledge of the girl's engagement in a risky activity (eg, biking or climbing monkey bars) immediately before the injury. RESULTS: Fifty-six girls were evaluated. Age range: 1 to 12 years (median, 6 years; mean, 6.2 years). Associations: bicycle, 39%; other outdoor injuries, 25% (climbing apparatus, straddling an object, and falls); indoor injuries, 36% (straddling furniture and falls). Most injuries were minor. In each group the labia minora was the most frequent structure involved. The majority of injuries were anterior or lateral to the hymen. However, in 34% some or all of the injuries were posterior to the hymen. Thigh injuries were observed only in older children engaged in bicycle riding or outdoor play. In only one patient was the hymen involved. That patient was a 2 year old who fell outdoors, at a park, abducting her legs in a splits-type mechanism. She had a pinpoint abraded area on the hymenal surface at three o'clock. Otherwise, no unique pattern of injury was associated with age or circumstance of injury. CONCLUSIONS: Hymenal injuries are rarely the result of unintentional injury. The presence of a hymenal injury should suggest sexual abuse. Involvement of other perineal structures was commonly associated with unintended injury. Given the limited resources for prevention, the relative infrequency of perineal injuries and the minor nature of most of these injuries, significant preventive efforts are not justified.

The psychosocial consequences of traumatic injury.

Long-term stress experienced by trauma patients was assessed for a sample of 137 patients treated at a large urban trauma center after suffering traumatic injuries resulting from motor vehicle/motorcycle accidents, falls, pedestrian accidents, and stabbing and gunshot wounds. Levels of psychological distress reported 3 to 39 months after the accident were considerable, but a measure of injury severity commonly used in critical care settings was not a good predictor of psychosocial outcome. The subjective impact of the accident and injury-related financial and employment problems were more important in predicting outcome than medical variables or time since injury. Family environment ratings were significantly worse for subjects with elevated levels of psychiatric symptoms. The results suggest that psychosocial interventions may benefit many of these individuals. Aspects to be considered in planning the intervention include projected functional disability, likely employment and financial problems, subjective perceptions of the accident and its implications, and family and social support.

Injuries associated with downhill sledding.

During the winter season of 1985 to 1986, 30 children presented to the emergency department with injuries related to downhill sledding. All of the patients were seen and treated during December 1985, which was an unusually cold and snowy month. The age range of the patients was six to 16 years. Six patients required admission, and all were related to head and/or abdominal trauma. The special characteristics of the sled, the environment, and the rider work in concert to produce injuries. The injury is most likely to occur under cold, icy conditions. After analysis of this series of patients, it is concluded that downhill sledding injuries can be minimized. The factors that make this activity dangerous are defined, and safety precautions are suggested.

Emergency gastrotomy: treatment of choice for iron bezoar.

The authors believe that gastrotomy and surgical removal of tablets is the treatment of choice in massive iron ingestion with development of an "iron bezoar" unresponsive to gastric lavage. Prompt surgical treatment in such cases may be lifesaving.