Effects of ondansetron on emesis in the first 24 hours after craniotomy in children.

Children undergoing neurosurgical resection are at high risk for postoperative nausea and vomiting. Ondansetron, a selective serotonergic (5-HT3) antagonist, is effective in reducing postoperative vomiting in several high-risk populations. In a prospective, randomized study, we compared the prophylactic use of intravenous ondansetron, 0.15 mg/kg, versus placebo for the prevention of emesis in 60 children, aged 2-18 yr, undergoing craniotomies for resective procedures. Patients with preoperative emesis were excluded from the study. All patients were tracheally extubated at the conclusion of surgery, and each episode of emesis during the first 24 postoperative hours was recorded. For the entire 24-h interval, the incidence of emesis in children who received ondansetron (57%) was not significantly different from that in those who received placebo (66%); however, in the first 8 h, the incidence was 25% (ondansetron) vs 44% (placebo) (P = not significant). In those receiving placebo, there was no difference in emesis between patients undergoing operations above versus below the tentorium. Although our sample size was too small to completely exclude any beneficial effect, ondansetron appears ineffective in preventing postoperative emesis in this patient population.

Risk of high spinal anesthesia following failed epidural block for cesarean delivery.

Recent case reports suggest there may be an increased risk of abnormally high blockade ("high spinal") from subarachnoid anesthesia if it is performed immediately after epidural anesthesia. We describe two cases of high spinal anesthesia following failed epidural block in obstetric patients scheduled for cesarean delivery. Using a retrospective chart review, we estimate the incidence of high spinal anesthesia to be 11% in patients after prior failed epidural blockade versus fewer than 1% in patients undergoing spinal anesthesia alone.

Prophylactic antiemetic treatment with ondansetron in children undergoing tonsillectomy.

BACKGROUND: Children undergoing tonsillectomy are at high risk for postoperative vomiting. This study was undertaken to compare ondansetron with metoclopramide and droperidol for the prevention of postoperative vomiting after tonsillectomy. METHODS: Two hundred fifty-six pediatric patients, ages 2-12 years, scheduled for outpatient tonsillectomy were enrolled in a prospectively randomized, double-blinded investigation and assigned to one of four treatment regimens: placebo (saline), ondansetron 0.15 mg.kg-1, metoclopramide 0.5 mg.kg-1, or droperidol 0.075 mg.kg-1. Study drugs were administered intravenously after inhalation induction of anesthesia with halothane, nitrous oxide, and oxygen. No premedication or neuromuscular blocking agents were used. Tracheal extubation was performed while patients were still deeply anesthetized. Acetaminophen and meperidine were given for postoperative pain. Patients were observed in the recovery room for a minimum of 4 h before discharge. Parents were contacted by telephone 24 h later for follow-up. RESULTS: Ondansetron reduced the incidence of postoperative emesis from 62% to 27% (relative risk 0.45, 95% confidence interval 0.29 to 0.70, P < 0.001). Metoclopramide and droperidol had no significant effect on postoperative vomiting. CONCLUSIONS: The intravenous administration of ondansetron 0.15 mg.kg-1 is highly effective in reducing postoperative emesis in children undergoing tonsillectomy. Metoclopramide and droperidol at the doses tested are ineffective in this population.

A double-blinded comparison of metoclopramide and droperidol for prevention of emesis following strabismus surgery.

Vomiting in the postoperative period is common in children after strabismus surgery. One hundred ten pediatric patients, ages 8 months to 14 yr, admitted for outpatient strabismus surgery were enrolled in a randomized, double-blinded study to compare droperidol and metoclopramide to placebo for the prevention of postoperative emesis. Each child was prospectively assigned at random to one of four treatment groups: metoclopramide 0.15 mg/kg, metoclopramide 0.25 mg/kg, droperidol 0.075 mg/kg, or saline control. Drugs were administered intravenously immediately after induction of inhalation anesthesia. No neuromuscular blocking agents were used. Tracheal extubation was performed while patients were still deeply anesthetized. Acetaminophen and meperidine were given in standard doses for postoperative pain to all children. The incidence of vomiting was less in both the droperidol (33%) and metoclopramide 0.25 mg/kg (29%) groups when compared to controls (88%) (P less than 0.01). Patients receiving metoclopramide 0.15 mg/kg had a 68% incidence of vomiting (P not significant). The mean frequency of emesis was reduced in all treatment groups compared with control (P less than 0.05). Patients receiving droperidol and metoclopramide 0.25 mg/kg also had decreased postoperative stays (metoclopramide 201 min; droperidol 213 min) versus control (258 min, P less than 0.05). No child exhibited extrapyramidal symptoms, excessive drowsiness, or agitation. We conclude that metoclopramide in a dose of 0.25 mg/kg, administered prior to the start of surgery, is at least as effective as droperidol in preventing postoperative emesis and can reduce the time to patient discharge compared to control.

The asymptomatic patient with suspected myocardial contusion.

Diagnostic criteria and guidelines for hospital admission for suspected myocardial contusion (MCC) remain unclear. This study defines and examines the clinical sequelae of patients admitted with a suspicion of MCC. Criteria for observation following isolated, minor blunt chest trauma are suggested. Hospital and trauma registry records of patients admitted over a 33-month period with suspected MCC were reviewed. Conventional evaluation criteria, cardiac-related complications, and associated injuries were analyzed for 524 patients. Twenty-eight cardiac-related complications occurred in 27 of 524 patients (5%). These complications included 23 dysrhythmias, 3 infarctions, and 2 pericardial effusions. There were 23 patients with abnormal admission electrocardiograms and 4 with normal ones. Of the latter, one patient developed dysrhythmia 4 hours after admission, and three had other major multi-system injuries requiring admission to the intensive care unit. The overall incidence of cardiac-related complications in minimally injured patients was 0.1%. There were no complications in patients with isolated chest wall contusions, a normal admission electrocardiogram, and a normal rhythm at 4 hours. There was no significant association between creatine phosphokinase isoenzymes or echocardiogram and cardiac-related complications. The complete absence of significant cardiac sequelae in patients with isolated chest wall contusion, normal admission and 4-hour electrocardiograms, and no other associated major injuries suggests that these patients need not be admitted.

Dexmedetomidine, a selective alpha 2-agonist, does not potentiate the cardiorespiratory depression of alfentanil in the rat.

The authors examined the cardiovascular and respiratory effects of the highly selective alpha 2-adrenergic agonist dexmedetomidine, both alone and in combination with the synthetic opiate alfentanil. Spontaneously ventilating rats (n = 28) were pretreated with dexmedetomidine, 10 or 30 micrograms/kg; dexmedetomidine, 30 micrograms/kg in combination with the central-acting alpha 2-antagonist idazoxan, 10 mg/kg; or vehicle. Fifteen minutes later all rats received alfentanil, 500 micrograms/kg. Pretreatment with dexmedetomidine reduced heart rate in a dose-related fashion. Administration of alfentanil also caused a significant reduction in heart rate. However, following alfentanil, the dexmedetomidine-treated animals did not have significantly greater bradycardia than control animals. An increase in blood pressure was observed in those animals receiving the larger dose of dexmedetomidine, but this difference disappeared following injection of alfentanil. The addition of idazoxan to the pretreatment regimen prevented the changes seen with dexmedetomidine. Pretreatment with dexmedetomidine produced no significant changes in arterial pH or PCO2. In all groups, administration of alfentanil resulted in a decrease in arterial pH that ultimately became a mixed respiratory and metabolic acidosis. The acidosis promptly resolved following injection of naloxone (1 mg/kg). It appears that dexmedetomidine, at the doses given, has little or no effect on respiration. Dexmedetomidine decreases heart rate but does not add to bradycardia following alfentanil. There is a hypertensive effect seen at the higher dose of dexmedetomidine, but this effect disappears when the drug is given in conjunction with alfentanil. These data show that addition of the alpha 2-agonist dexmedetomidine will not worsen the cardiovascular and respiratory depression associated with high-dose opiates in the spontaneously ventilating rat.

Pseudopseudarthrosis in a patient with ankylosing spondylitis.

There is a growing consensus that the mechanism leading to extensive discovertebral destruction (type III) in most patients with ankylosing spondylitis relates to fracture and subsequent pseudarthrosis. We introduced the term "pseudopseudarthrosis" to describe (in our case) the occurrence of abnormal motion between 2 fused spinal segments, resulting in extensive discovertebral destruction without fracture or pseudarthrosis.

Prospective, randomized trial of hypertonic sodium lactate versus lactated Ringer's solution for burn shock resuscitation.

We prospectively randomized 51 adult burned patients on admission to study fluid, electrolyte, and physiologic parameters during burn resuscitation with the use of hypertonic saline (HSL, Na 250 mEq/L, 514 mOsm) or lactated Ringer's solution (LR, Na 130 mEq/L, 268 mOsm). Patients suffered at least 20% total body surface area burns (BSA); the mean BSA injury was 36.7% BSA, with a range of 20 to 74% BSA. All patients were admitted to our Burn Center within at least 12 hours of injury. Laboratory studies included frequent determinations of serum chemistries including osmolalities, and continuous 24-hour urine collections for electrolytes and osmolality determinations. Fluid requirements (cc/kg/% BSA), urine output (cc/kg/hr), sodium intake and excretion (mEq/kg/% BSA), serum and urine osmolality (mOsm/kg), serum creatinine (mg/dl), body weight (kg), and enteral intake (cc/24 hrs and calories/24 hrs) were analyzed for comparison at 24-hour intervals following burn injury. Using Student's t-test, significance was attributed to a p less than 0.05. Nonparametric methods were used to compare non-normalized data. Regression analysis was used to compare sodium intake (mEq/kg) and fluid intake (cc/kg) between the HSL and the LR groups in relation to % BSA. Our data show no advantage of HSL over conventional therapy with LR for burn resuscitation. We were not able to demonstrate decreased fluid requirements, improved tolerance of feedings, or decrease in per cent weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)