Preemptive Analgesic Effect of Two Doses of Ketamine for Postoperative Pain Relief in Children Following Adenotonsillectomy / 医学研究杂志

Objective To investigate the efficacy of two low doses of ketamine for postoperative pain relief in children following adenotonsillectomy.Methods Ninety ASA physical status Ⅰ patients,aged 2-9 years,scheduled for adenotonsillectomy were enrolled in this randomized,double-blinded study.Patients were divided into three groups of 30 each and received an intravenous injection of 0.9％ saline (group C),ketamine 0.2mg/kg (group K1),or ketamine 0.5mg/kg (group K2).FLACC scores were used to evaluate pain levels during 12h after surgery.Tramadol and diclofenac potassium suppositories were provided for pain relief if FLACC ＞ 4.The operating time(OT),anesthesia duration(AT),extubation time(ET) and awaking time(AWT) were recorded.Adverse reactions such as nausea,vomiting,headache,abdominal pain and the requirement of rescue analgesic was recorded.Results Group C had significant higher FLACC scores than group K1 and K2 during the first 30min after operation.The requirement of analgesics was also higher in the control group(P ＜ 0.05).No significant difference of FLACC scores was found between group K1 and K2.However,children in K2 group have longer awaking time (P ＜ 0.05).There was no significant difference among three groups in the FLACC score after 2 hours.Conclusion A 0.2 or 0.5mg/kg dose of ketamine given before surgery by intravenous injection provides efficient pain relief in the early period after surgery.0.2mg/kg may be preferable for its low incidence of deep sedation.

Production of deuterated zeaxanthin by Flavobacterium multivorum and its detection by resonance Raman and mass spectrometric methods.

Flavobacterium multivorum, a zeaxanthin-producing organism, was grown aerobically in a medium prepared with deuterated water. Atmospheric pressure chemical ionization mass spectrometry (APCI-MS) and resonance Raman spectroscopy (RRS) analysis revealed approximately 75% replacement of hydrogen by deuterium atoms as indicated by the molecular mass cluster at around m/z 600. Deuterated zeaxanthin upon excitation with a 488 nm laser exhibited characteristic resonance Raman vibrational modes at 1,161 and 1,504 cm(-1) as compared to 1,007, 1,159 and 1,525 cm(-1 )for undeuterated zeaxanthin. HPLC/APCI-MS and HPLC/RRS were specific and sensitive with limits of detection of 2.5 pg and 50 ng, respectively.