Effect of timing of ondansetron administration on incidence of postoperative vomiting in paediatric strabismus surgery

This prospective, randomized, double-blinded study evaluated the effect of the timing of ondansetron administration on its antiemetic efficacy in children undergoing elective strabismus surgery. One hundred and twenty children aged one to 15 years, ASA physical status 1 or 2, were randomly allocated to receive intravenous ondansetron 100 micrograms/kg either at induction (Group 1) or at the end of the surgery (Group 2). All patients had general anaesthesia induced and maintained with nitrous oxide and halothane, muscle relaxation with vecuronium, endotracheal intubation, reversal with neostigmine and glycopyrrolate, and pethidine 0.5 mg/kg analgesia. Episodes of nausea and vomiting were evaluated at 0 to 2, 2 to 6 and 6 to 24 hour intervals by a blinded observer. Demographic data, duration of anaesthesia, type of surgery, incidence of previous postoperative nausea or vomiting and motion sickness and number of patients who developed oculocardiac reflex requiring atropine treatment were similar in both groups. The incidence of emesis in the first 24 hours following surgery was similar in both groups (35% Group 1, 33.3% Group 2, P = 1.00). Severity of emesis (median number of emetic episodes, rescue antiemetic requirement and mean time to the onset of first episode of emesis) and mean time to discharge from the post anaesthesia care unit were also similar in the two groups. We conclude that the timing of ondansetron administration either before or after the surgical manipulation of extraocular muscles had similar antiemetic efficacy following strabismus surgery in children.     

The Right Atrial Free Wall: An Alternative Pacing Site

A major advantage of active fixation permanent pacing leads is their ability to be actively attached in areas where conventional passive fixation leads cannot be. In a review of records of 134 consecutive patients requiring dual chamber pacing, all of whom received active fixation atrial leads, 56 had right atrial appendage (AA) pacing and 78 had right atrial free-wall (AFW) pacing. Acute electrical parameters including sensed P wave amplitude (AA - 5.6 ± 2.3 mV. AFW = 5.5 ± 2.3 mV), slew rate (AA = 1.21 ± 0.77 V/sec, AFW = 1.20 ± 0.74 V/sec), stimulation thresholds (voltage and current) including rheobase voltage (AA = 0.6 ± 0.2 V, AFW - 0.6 ± 0.2 V), and pacing impedance (AA = 516 ± 89 ohms, AFW = 504 ± 84 ohms) were similar in both groups. There were two dislodgements fatrial appendage group) and no episodes of clinically important perforation or diaphragmatic stimulation. The free wall of the right atrium appears to he an excellent alternative pacing site to the appendage.     

脑室注射催产素对大鼠胃和十二指肠溃疡的作用

INTRODUCTION Central neurons that synthesize oxytocin are locatedin the supraoptic(SON) and paraventricular nuclei(PVN) of the hypothalamus. Magnocellular neurons inboth nuclei project to the posterior pituitary gland,     

Transesophageal Echocardiographic Evaluation for Mural Thrombus Following Radiofrequency Catheter Ablation of Accessory Pathways

Background: Catheter ablation of accessory pathways (APs) provides a definitive therapy for patients with Wolff-Parkinson-White Syndrome. The reported incidence of thrombus formation on ablation-induced injuries with direct current shock varies from 0%-20% in animal studies. The purpose of this study was to determine the prevalence of mural thrombus following catheter ablation with radiofrequency current of accessory pathways in humans. Methods and Results: Radiofrequency current (30–35 warts) was applied through a catheter electrode placed against the mitral or tricuspid annulus guided by catheter recordings of AP potentials. Transthoracic (TTE) and transesophageal echocardiography (TEE) were performed in 95 of 111 patients, at 18 ± 6 hours following catheter ablation. After ablation. no thrombus was identified at or near the ablation site in any patient. Two out of 95 patients had a mural thrombus at a remote site that was detected by TEE but not by TTE. No new wall motion abnormality was detected in any patient. No significant regurgitant valvular lesion was found in any patient. Conclusion: Intracardiac thrombus was not identified at the site of catheter ablation, possibly owing to the small lesions produced by radiofrequency energy and high blood flow normally present in those areas. However, patients may be at small risk for mural thrombus at a remote site from prolonged placement of catheters.