腹部手术后患者静脉输注丁丙诺啡镇痛的可行性

目的 评价腹部手术后患者静脉输注丁丙诺啡镇痛的可行性.方法 采用多中心、随机、开放、平行、阳性药物对照进行研究,择期全身麻醉下行腹部手术患者200例,年龄18～64岁,ASAⅠ级或Ⅱ级,性别不限,体重50～100 kg,随机分为丁丙诺啡组(B组)和芬太尼组(F组),每组100例.2组术后分别静脉输注丁丙诺啡0.3 μg·kg-1·h-1、芬太尼0.3 μg·kg-1·h-1.采用视觉模拟评分法(VAS评分)评价术后6、12、24、36和48 h的疼痛程度,于各时点行镇静评分及Prince-Henry评分,监测心率、呼吸频率(RR)和脉搏血氧饱和度(SpO2),记录不良反应的发生情况.结果 与F组比较,B组各时点VAS评分、镇静评分和Prince-Henry评分差异无统计学意义(P＞0.05),恶心发生率较低(P＜0.05);两组各时点RR和SpO2差异无统计学意义(P＞0.05).结论 静脉输注丁丙喏啡0.3 μg·kg-1·h-1可有效缓解腹部手术后患者疼痛,且不良反应少.     

脊髓水平GABAA受体在异丙酚对内脏痛大鼠镇痛效应中的作用

目的 探讨脊髓水平γ-氨基丁酸（GABA）A受体在异丙酚对内脏痛大鼠镇痛效应中的作用。方法 35只雄性SD大鼠，体重180—240g，随机分为5组，每组7只，腹腔注射生理盐水0．5ml组（C组），腹腔注射异丙酚10mg／kg组（P1组），腹腔注射异丙酚20mg/kg组（P2组），鞘内注射荷包牡丹碱0．25馏组（B组），鞘内注射荷包牡丹碱0．25μg＋腹腔注射异丙酚10mg/kg组（BP组）。采用结直肠扩张法制备内脏痛动物模型，以腹壁明显收缩变平的最小扩张压力值为痛阈，观察给药前即刻（T0）及给药后5min（T1）、10min（T2）、15min（T3）、20min（T4）、25min（T5）、30min（k）、40min（B）、50min（T8）大鼠的痛阈，并计算最大镇痛效应百分率（MPE）。结果 与C组比较，P1组T1-4时、P2组T1-5，时的痛阈升高（P〈0．05或0．01）；与P1组比较，P2组痛阈升高（P〈0．01）。与P1组比较，B组T1-4时MPE降低，BP组T2-4时MPE升高（P〈0．05或0．01）；与B组比较，BP组，T1-4时MPE升高（P〈0．05或0．01）。结论 异丙酚部分通过介导脊髓水平GABAA受体，对大鼠结直肠扩张所致内脏痛具有镇痛作用。     

腰方肌阻滞对腹腔镜肝切除术后急性疼痛影响的回顾性研究

目的　回顾性分析腰方肌阻滞对腹腔镜肝切除术后急性疼痛的影响。 方法　选取2018年1~8月于我院行择期腹腔镜肝切除术患者24例，平均分为2组，对照组仅采用全凭静脉麻醉，腰方肌组采用腰方肌阻滞（quadratus lumborum block，QLB）联合全凭静脉麻醉，两组术后镇痛方案均为自控静脉镇痛（patient controlled intravenous analgesia，PCIA）。麻醉期间常规监测患者心率、血压、脉搏氧饱和度，采用腰方肌阻滞的患者在阻滞完成后15 min记录阻滞平面。分别于术前、术后2 h、术后8 h、术后12 h、术后24 h和术后48 h对患者进行VAS评分。记录患者术中和术后PCIA阿片类药物消耗情况及术后48 h内恶心呕吐、尿潴留、瘙痒和呼吸抑制等并发症发生情况。 结果　腰方肌组患者在术后2、8、12 h 3个时间点VAS评分显著低于对照组，差异具有统计学意义（P<0.05）。腰方肌组12名患者最高阻滞平面为T6（T6~10），最低阻滞平面为L1（T12~L1）。与对照组相比，腰方肌组术中和术后PCIA阿片类药物消耗均显著减少，差异具有统计学意义（P<0.05）。 结论　腰方肌阻滞能够有效缓解腹腔镜肝切除术患者术后急性期疼痛，减少围术期阿片类药物用量。     

疼痛模型大鼠下丘脑和脊髓P物质的含量变化

目的疼痛模型大鼠下丘脑和脊髓P物质（substance P，SP）的含量变化。方法左足跖皮下注射5％甲醛50μl建立大鼠疼痛模型，将动物随机分成空白对照组，生理盐水对照组和疼痛模型组，采用放射免疫分析法测定股动脉血、下丘脑和脊髓中SP的含量。结果疼痛模型组雄性S-D大鼠血浆中及下丘脑和脊髓SP含量分别与空白对照组、生理盐水对照组差别有统计学意义（P〈0．05）；而空白对照组与生理盐水对照组差别无统计学意义（P〉0．05）。结论皮下注射5％甲醛可致疼痛症状产生；提示皮下注射甲醛所致疼痛可通过下丘脑和脊髓组织中的SP释放增加，所致无菌性炎症反应而引起疼痛症状。     

Involvement of protein kinase c in responses of rat dorsal horn neurons to mechanical stimuli and periaqueductal gray descending inhibition

 The effects of a protein kinase C (PKC) activator, 12-O-tetradecanoylphorbol-13-acetate (TPA), on the activity and periaqueductal gray (PAG)-induced inhibition of rat dorsal horn neurons of the lumbar spinal cord were tested. A microdialysis fiber was placed through the dorsal horn for the purpose of local application of pharmacological agents. Extracellular single-unit recordings from dorsal horn neurons were made near the microdialysis fiber. TPA was tested on nociceptive dorsal horn cells. There was a significant increase in the background activity and responses to ”brush”, with no changes in responses to pressure and pinch stimuli. TPA also significantly blocked the PAG-induced inhibition of responses to brush, press, and pinch. These effects were eliminated by coadministration of the PKC inhibitor NPC-15437. The solvent, which contained dimethyl sulfoxide, was also tested for its effect on the responses to peripheral mechanical stimuli and PAG-induced inhibition of the dorsal horn neurons. There were no significant changes. This experiment suggests that activation of the PKC second messenger system might increase the activity of dorsal horn neurons and their responses to peripheral stimuli; in addition, the phorbol ester attenuated the PAG-induced descending inhibition of the dorsal horn neuron activity. Received: 15 May 1996 / Accepted: 14 November 1996     

Intra-articular morphine and postoperative analgesia after knee arthroscopy

The aim of this study was to evaluate the postoperative analgesic effect of intra-articular administration of a low- and a high-dose morphine solution after knee arthroscopy. Thirty patients who underwent diagnostic arthroscopy or arthroscopic meniscectomy were allocated in three groups. At the end of the arthroscopic procedure patients in Group A received intra-articularly 20 ml normal saline (N/S), Group B received 5 mg morphine in 20 ml N/S and Group C received 15 mg morphine in 20 ml N/S. The postoperative pain was assessed using a visual analogue scale for 24 h, while all the patients stayed at hospital. Side effects from the central action of opioids were not detected. Although the pain scores in the group of low-dose morphine were lower than in the control group, we failed to detect any significant differences in pain scores among the three groups. There was evidence that a high-dose can cause hyperalgesia.     

Multivariate Genetic Analysis of Chronic Pelvic Pain and Associated Phenotypes

Chronic pelvic pain (CPP) is a common condition in women that is difficult to diagnose. Although heritability estimates have been published for some conditions potentially underlying pelvic pain, the heritability of CPP itself has never been investigated. Using data from 623 MZ and 377 DZ female twin pairs aged 29–50 from an Australian twin cohort, we found an increased CPP concordance among MZs compared to DZs, with tetrachoric correlations of 0.43 (95% CI: 0.26–0.58) and 0.11 (95% CI: –0.16–0.38), respectively. This corresponded to a heritability of 0.41 (95% CI: 0.25–0.56). Lack of correlations with environmental indicators suggested that violation of the equal environments assumption was not responsible for this effect. Multivariate Cholesky decomposition models incorporating CPP and significantly correlated phenotypes showed that the entire CPP heritability could be explained by genetic variance underlying endometriosis (38%), dysmenorrhoea (23%), fibroids (24%), and somatic distress (15%), the latter a possible indicator of increased nociception. CPP itself is unlikely to be a useful independent phenotype to conduct genetic aetiological studies; contributing conditions such as endometriosis and variation in nociception are likely to provide more useful phenotypes.     

Contact heat evoked potentials to painful and non-painful stimuli: effect of attention towards stimulus properties

The study aim was to evaluate the effect of different attentional tasks on the amplitudes and latencies of painful and non-painful contact heat evoked potentials (CHEPs). CHEPs were recorded in 12 healthy subjects during two experimental conditions, in which attention was oriented towards the intensity and the distress caused by the stimuli and were compared with CHEPs recorded during a neutral condition. The painful heat stimulation produced a negative potential at Cz vertex with a latency around 540 ms (Cz/N540), a positive peak at Cz electrode around 730 ms (Cz/P730) and, lastly, a positive peak around 1000 ms (Pz/P1000) in the Pz traces. The Cz/P730 wave was significantly higher in amplitude only during the painful stimulation and is probably related to coding the nociceptive activity. Varying the attentional target towards different properties of the stimulus did not cause any significant change in CHEP responses amplitude and latencies compared with the neutral condition. Our results suggest that CHEPs represent a reliable functional measure of the nociceptive pathways and that they are generated by the activation of different cerebral areas involved in pain processing. The high activation level of each of these area or their spatial neighbouring might explain the strong similarity of CHEP components recorded during different attentional manipulations.     

Salivary cooling,escape reaction and heat pain in capsaicin-desensitized rats

Salivary thermolytic mechanism (weight of salivary glands, effect of desalivation on water intake and body temperature, grooming activity) as well as escape behaviour and reaction to heat pain were studied in capsaicin-desensitized and control rats exposed to various warm ambient temperatures. Body temperature of the desensitized rats increased more than the controls at all the ambient temperatures studied (32, 34 and 36°C); however, significant differences in the mechanism of salivary cooling were obtained only at 34 and 36°C. Central impairment of saliva spreading in desensitized rats seems evident. Complete surgical desalivation did not increase hyperthermia of control and desensitized animals in warm environments. Therefore other mechanisms, primarily vasodilatatory, must also be involved in the rat's thermolytic normal response. Although desensitized rats did not show a tendency to escape from the warm environment their response to heat pain was normal. In conclusion, it is suggested that heat perception in desensitized animals is impaired; however, the existence of some capsaicin-insensitive thermolytic mechanisms (prone extension of the body) cannot be excluded.Supported by the Scientific Research Council, Ministry of Health, Hungary /4-05-0303-04-2/0/ and MTA-OM-MÉM-EÜM 70.211/79