Juan Ni

Effect of Dexmedetomidine on Preventing Postoperative Agitation in Children: A Meta-Analysis

Background Emergence agitation (EA) is one of the most common postoperative complications in children. The purpose of this meta-analysis is to assess the effect of dexmedetomidine for preventing postoperative agitation in children. Methods We searched the Cochrane Central Register of Controlled Trails, MEDLINE, and EMBASE. Randomized controlled trials were included. The following outcome measures were evaluated: incidence of EA, number of patients requiring rescue, time to eye-open, time to extubation, time to discharge from the postanesthesia care unit (PACU). Results We analyzed 19 trials (1608 patients) that met the inclusion criteria. Compared with placebo, intravenous dexmedetomidine significantly reduced the incidence of EA [risk ratio (RR) 0.34, 95% confidence interval (CI) 0.25–0.44, P<0.00001). Dexmedetomidine also decreased the incidence of severe pain (RR 0.41, 95% CI 0.27–0.62, P<0.0001) and requirement of a rescue drug (RR 0.31, 95% CI 0.18–0.53, P<0.0001). However, compared with placebo, dexmedetomidine increased the time to eye-open by 0.98 min (P = 0.01) and the time to PACU discharge by 4.63 min (P = 0.02). Dexmedetomidine was also compared with midazolam, propofol, ketamine, and fentanyl, among others. No significant difference was found in the incidence of EA for most of these comparisons, with the exception of fentanyl and propofol, where dexmedetomidine was more beneficial. Conclusions Dexmedetomidine was proved effective for preventing EA and for reducing severe pain and the requirement of rescue drugs. It slightly increased the time to eye-open and the time to PACU discharge. Dexmedetomidine was also more beneficial than propofol or fentanyl in preventing EA.

Ultrasound-guided epidural anesthesia for a parturient with severe malformations of the skeletal system undergoing cesarean delivery: a case report.

Anesthetic management of patients with preexisting diseases is challenging and individualized approaches need to be determined based on patients’ complications. We report here a case of ultrasound-guided epidural anesthesia in combination with low-dose ketamine during cesarean delivery on a parturient with severe malformations of the skeletal system and airway problems. The ultrasound-guided epidural anesthesia was performed in the L1–L2 space, followed by an intravenous administration of ketamine (0.5 mg/kg) for sedation and analgesia. Satisfactory anesthesia was provided to the patient and spontaneous ventilation was maintained during the surgery. The mother and the baby were discharged 5 days after surgery, no complications were reported for either of them. Our work demonstrated that an ultrasound-guided epidural anesthesia combined with low-dose ketamine can be used to successfully maintain spontaneous ventilation and provide effective analgesia during surgery and reduce the risk of postoperative anesthesia-related pulmonary infection.

Stimulation of contractions in pregnant human myometrium is associated with 5-HT3 receptors

BACKGROUND Serotonin (5-HT) is known to play an important role in regulating uterine contractions. However, the specific receptors involved have not been well characterized. We evaluated whether 5-HT3 receptors exist in human myometrium, and their effects on myometrial contractility when stimulated by a 5-HT3 agonist. METHODS Four tissue samples taken from patients undergoing hysterectomy (n=2) and elective cesarean delivery (n=2) were used to detect expression of 5-HT3 receptors on the myometrium using western blotting. For isometric tension measurement, another 12 myometrial strips obtained from patients undergoing elective cesarean delivery were randomly divided into a control group (Group CON) and an RS56812 group (Group RG). In increasing doses from 10-7M to 10-4M, RS56812, a 5-HT3 receptor agonist, was used to investigate the contractile effects after bonding to the 5-HT3 receptor, following which the effects of granisetron were assessed. Amplitude, interval and duration of myometrial contractions were recorded. RESULTS Proteins with a molecular mass of 55kDa, consistent with 5-HT3 receptors, were detected both on non-pregnant and late-pregnant human uteri. RS56812 increased the contractile amplitude at concentrations of 10-6M, 10-5M and 10-4M, achieving maximum effect at 10-5M. A prolonged contractile interval was detected at the concentration of 10-4M. However, RS56812 showed no significant effect on contraction duration. Granisetron did not reverse the contractile effects induced by RS56812. CONCLUSION 5-HT3 receptors are expressed on non-pregnant and pregnant uteri. RS56812 enhanced myometrial contractions, but this was not affected by granisetron, the mechanism of which requires further investigation.

Epidural analgesia confusing the diagnosis of spontaneous acute thoracic epidural hematoma after cesarean section

To the Editor: A 31-year-old woman underwent cesarean section because of fetal distress. An epidural anesthesia was carried out in the L1–L2 space. The lumbar puncture and surgery were uneventful. An epidural catheter was placed for patientcontrolled epidural analgesia (PCEA) using 0.125 % bupivacaine with sufentanil (0.5 lg/ml). The basal infusion rate was 4 ml/h, with a 2-ml bolus available every 20 min. The patient recovered from the anesthesia 4 h after the surgery, and started to notice mild pain in the left scapular region and back at 15 h after the surgery. At 24 h after surgery, the patient noticed sensory deficits in both legs, but motor function was not affected. The epidural catheter was removed, but motor function became affected, with weakened deep tendon reflexes below the T3 level at 29 h after the surgery. Both bladder and bowel continence was impaired. A diagnosis of epidural hematoma at the T1–T3 level was established with magnetic resonance imaging (Fig. 1). Thirty-one hours after the surgery, emergency surgery was carried out to remove the hematoma. The patient was able to walk with a cane after 1 year. A followup at 5 years revealed some permanent motor neurological damage. Spontaneous epidural hematoma has been reported during pregnancy in both the cervical and thoracic segments [1, 2]. In such cases, pain typically occurs abruptly, and progresses rapidly to paraplegia. In patients receiving regional anesthesia and PCEA, such as in this case, the lower-extremity symptoms of epidural hematoma are often confused with the neuraxial block. In this case, the pain was mild initially, and the progression was slow. Thus, the recognition of epidural hematoma was difficult. Spontaneous epidural hematoma tends to occur in patients with coagulation deficits, and could be secondary to other conditions, such as preeclampsia and liver diseases [3]. None of the known risks was present in this case. Also, we did not notice hemangioma, vascular malformation, or intraspinal tumor bleeding, suggesting the spontaneous nature of the hematoma. Neurological recovery is more likely if surgical decompression is carried out within 8 h from the onset. In this case, surgical decompression was carried out at 16 h