Buprenorphine as premedication and as analgesic during and after light isoflurane-N2O-O2 anaesthesia. A comparison with oxycodone plus fentanyl

Sixty patients undergoing gynaecological laparotomies under isoflurane anaesthesia received 0.4 mg of buprenorphine sublingually or 0.12 mg/kg of oxycodone intramuscularly in random order for preanaesthetic medication. Patients premedicated with buprenorphine were given buprenorphine before, during and after anaesthesia and patients premedicated with oxycodone received fentanyl before and during anaesthesia and oxycodone after anaesthesia. Buprenorphine premedication produced less drowsiness and sedation and alleviated patients' apprehension significantly (P less than 0.05) less than oxycodone. Systolic and diastolic blood pressure and heart rate were significantly (P less than 0.05 to P less than 0.01) higher after intubation in the buprenorphine group when compared with the oxycodone plus fentanyl group. After anaesthesia, spontaneous respiration started rapidly; the return of consciousness and immediate recovery occurred at the same rate in both groups. In the recovery room moderate to severe pain was more common (P less than 0.05) in the oxycodone plus fentanyl group than in the buprenorphine group. The respiratory rate in the recovery room was lower among patients given buprenorphine, and two patients given buprenorphine developed severe respiratory depression. In the ward (2 to 24 h after operation) sublingual buprenorphine provided pain relief as good as intramuscularly administered oxycodone. No differences were noted in the incidence or severity of emetic symptoms between the groups. It is concluded that buprenorphine can provide good postoperative pain relief for gynaecological laparotomies performed under light isoflurane anaesthesia, but patients need to be monitored carefully after operation because of the possibility of respiratory depression.     

Distribution of local anesthetics injected into the interpleural space, studied by computerized tomography

Twenty-one patients were given interpleural analgesia for postoperative pain relief after cholecystectomy, or renal or breast surgery. The patients were classified randomly into two groups: an interpleural injection of 20 ml of 0.375% bupivacaine mixed with 10 ml contrast medium was given to 11 patients in the supine position, and 10 in the lateral position. The patients remained in this position for 1 h. There was no significant difference in the rostrocaudal distribution of the contrast on computerized tomography taken 20 min later: Th3-L1 in the supine group vs. Th5-L1 in the lateral group. In the supine group the mean level of contrast medium reached significantly higher medially along the mediastinum (51 +/- 11 mm) than laterally (27 +/- 11 mm).     

局部麻醉药周围神经毒性防治的研究进展

当前,大量临床及基础实验研究结果证实局麻药具有周围神经毒性损伤作用.然而,具体的损伤机制仍未明确.故临床上尚无有效措施以防治局麻药的周围神经毒性损伤.综合国内外文献报道,在体及离体实验研究发现3类药物对局麻药的周围神经毒性损伤具有一定的拮抗作用,主要包括:①神经营养因子;②α-氨基羟甲基恶唑丙酸受体拮抗剂;③p38丝裂原性活化蛋白激酶抑制剂.上述药物虽可部分抑制局部麻醉药的周围神经毒性损伤,但能否应用于临床,仍需要未来进一步的研究证实.     

Mexiletine-responsive erythromelalgia due to a new Nav1.7 mutation showing use-dependent current fall-off

Inherited erythromelalgia (IEM), characterized by episodic burning pain and erythema of the extremities, is produced by gain-of-function mutations in sodium channel Na_v1.7, which is preferentially expressed in nociceptive and sympathetic neurons. Most patients do not respond to pharmacotherapy, although occasional reports document patients as showing partial relief with lidocaine or mexiletine. A 7-year-old girl, with a two-year history of symmetric burning pain and erythema in her hands and feet, was diagnosed with erythromelalgia. Treatment with mexiletine reduced the number and severity of pain episodes. We report here a new IEM Na_v1.7 mutation in this patient, and its response to mexiletine. SCN9A exons from the proband were amplified and sequenced. We identified a single nucleotide substitution (T2616G) in exon 15, not present in 200 ethnically-matched control alleles, which substitutes valine 872 by glycine (V872G) within DII/S5. Whole-cell patch-clamp analysis of wild-type and mutant Na_v1.7 channels in mammalian cells show that V872G shifts activation by − 10 mV, slows deactivation, and generates larger ramp currents. We observed a stronger use-dependent fall-off in current following exposure to mexiletine for V872G compared to wild-type channels. These observations suggest that some patients with IEM may show a favorable response to mexiletine due to a use-dependent effect on mutant Na_v1.7 channels. Continued relief from pain, even after mexiletine was discontinued in this patient, might suggest that early treatment may slow the progression of the disease.     

Hemodynamic and catecholamine response to isoflurane versus droperidol in complement to fentanyl anaesthesia

Droperidol (0.03 mg.kg-1 to 0.25 mg.kg-1) with fentanyl has been reported to be less efficient than volatile agents in the prevention of haemodynamic responses to surgery. The aim of this study was to investigate the use of high-dose droperidol in complement to fentanyl in comparison with isoflurane and fentanyl anaesthesia. Thirty patients undergoing laryngectomy were studied. Systolic blood pressure (SBP), heart rate (HR) and plasma catecholamines were analysed both during anaesthesia and during recovery. During surgery, SBP epinephrine (E) levels did not change in either group. HR was slightly lower during droperidol fentanyl anaesthesia. Norepinephrine (NE) levels were significantly higher in the droperidol group than in the isoflurane group (P less than 0.05). During recovery, in both groups, SBP increased by 20% whereas E levels increased by 65%. NE levels increased post-operatively in both groups, but this rise was significantly higher in the droperidol group (P less than 0.01). It is concluded that the two techniques contribute to the haemodynamic stability during surgery, but do not prevent haemodynamic instability during recovery.     

Role of cellular immunity in halothane hepatitis： an in vitro study

Objective： To explore the effect of cellular immunity in halothane hepatitis. Methods： Hepatotoxicity model was established by exposing male Hartley guinea pigs to 1% halothane via inspiration for 4 h each time for 1 or 3 times within a 42-day interval. Then their hepatocytes and lymphocytes were collected and divided into 2 parts for different cultures. Hepatocytes were cultivated with or without 1% halothane for 4 h and lymphocytes were cultivated with or without 12.5 μg/ml trifluoroacetylated guinea pig serum albumin （TFA-GSA）. Then the 2 kinds of hepatocytes were co-cultivated with lymphocytes （1：100） with or without TFA-GSA induction respectively and the supernatant fluid Was taken after 24, 48 and 72 h to determine the concentration of alanine aminotransferase （ALT）. The halothane cultivated hepatocytes were co-cultivated with various proportion of TFA-GSA antigen induced lymphocytes and ALT was determined after 48 h to determine the proper proportion of hepatocytes and lymphocyte. Results： Lymphocytes of 3 times halothane induced guinea pigs caused a significant increase of ALT in hepatocytes with or without halothane induction. But the lymphocytes of 1 time halothane induced guinea pigs only caused a significant increase of ALT in hepatocytes with induction of halothane. The increase of ALT was only seen after 48- and 72-hour co-culture. The proper proportion of hepatocytes and lymphocytes was 1：100 for lymphocytes cytotoxicity. Conclusion： Lymphocytes is sensitized after inhalation of halothane and generates cytotoxicity to hepatocytes. The immune response of lymphocytes to hepatocytes will be enhanced by repeated inhalation of halothane. The cellular immunity may be one of the mechanisms of halothane induced hepatotoxicity.     

混合预充液吸入麻醉药液/气分配系数的推算值

目的 :测定晶体与胶体混合预充液的液 /气分配系数 ,比较液 /气分配系数的推算值与实测值。　　方法 :利用计算机编制程序 ,将乳酸林格液、琥珀酰明胶注射液 (佳乐施 )、库血和人体血浆 4种体外循环预充液排列组合后 ,随机抽取样本 10份 ,采用注射器 2次平衡法 ,利用气相色谱仪测定混合预充液在 37℃、33℃、2 9℃、2 5℃、2 1℃和17℃ 6个不同温度点的液 /气分配系数 ,并与推算值比较。　　结果 :混合预充液 3种吸入麻醉药的液 /气分配系数均与温度呈负相关 ,6个不同温度液 /气分配系数的推算值与实测值呈直线关系 (P<0 .0 5 ,地氟醚 r=0 .94,异氟烷 (异氟醚 ) r=0 .95 ,氟烷 r=0 .93)。　　结论 :由公式推算吸入麻醉药混合预充液的液 /气分配系数是可行的。     

血液稀释对麻醉药物作用影响的研究进展

血液稀释（HD）是围手术期血液保护的重要方法之一,近年来在外科手术中应用广泛,其优点显而易见,但血液稀释会引起机体一系列的生理变化,从而可能影响术中麻醉药物的作用。本文就不同血液稀释方法对各种麻醉药物作用的影响作一综述。     

Effects of droperidol on peripheral vasculature: use of cardiopulmonary bypass as a study model

The effects of droperidol on the systemic vascular resistance (SVR) and the venous capacitance were studied during cardiopulmonary bypass (CPB) in 24 patients. CPB was performed with either pulsatile or non-pulsatile flow. During non-pulsatile flow, droperidol (0.15 mg X kg-1 and 0.30 mg X kg-1) decreased SVR and increased venous capacitance. These values were significantly different after the 2nd and the 7th min, respectively. During pulsatile flow, the initial SVR was lower. The decremental effect of 0.30 mg X kg-1 droperidol on SVR was proportional to the preinjection level of SVR (r = 0.64). The increase in venous capacitance related to droperidol was independent of the dose and of the type of flow in all patients. It can be concluded that the vasodilating action of droperidol during CPB on the arterial bed is transient, independent of dose, and related to the preinjection level of SVR. The effect of droperidol on venous capacitance is not as rapid but has a longer duration.