Alternatives to remifentanil for the analgesic component of total intravenous anaesthesia: a narrative review

Propfol-remifentanil-based total intravenous anaesthesia has dominated recent clinical practice due to its favourable pharmacokinetic profile. Interruption in remifentanil supply has presented an opportunity to diversify or even avoid the use of opioids and consider adjuncts to propofol-based total intravenous anaesthesia. Propofol, while a potent hypnotic, is not an effective analgesic. The administration of opioids, along with other adjuncts such as α-2 adrenoceptor agonists, magnesium, lidocaine, ketamine and nitrous oxide provide surgical anaesthesia and avoids large doses of propofol being required. We provide an overview of both target-control and manual infusion regimes for the alternative opioids: alfentanil, sufentanil and fentanyl. The optimal combination of hypnotic-opioid dose, titration sequence and anticipated additional postoperative analgesia required depend on the chosen combination. In addition, we include a brief discussion on the role of non-opioid adjuncts in total intravenous anaesthesia, suggested doses and expected reduction in propofol dose.     

Intra-operative analgesia with remifentanil vs. dexmedetomidine: a systematic review and meta-analysis with trial sequential analysis

Intra-operative remifentanil is associated with increased postoperative analgesic requirements and opioid consumption. Dexmedetomidine has characteristics suggesting it may substitute for intra-operative remifentanil during general anaesthesia, but existing literature has reported conflicting results. We undertook this meta-analysis to investigate whether general anaesthesia including dexmedetomidine would result in less postoperative pain than general anaesthesia including remifentanil. The MEDLINE and PubMed electronic databases were searched up to October 2018. Only randomised trials including patients receiving general anaesthesia and comparing dexmedetomidine with remifentanil administration were included. Meta-analyses were performed mostly employing a random effects model. The primary outcome was pain score at rest (visual analogue scale, 0–10) at two postoperative hours. The secondary outcomes included: pain score at rest at 24 postoperative hours; opioid consumption at 2 and 24 postoperative hours; and rates of hypotension, bradycardia, shivering and postoperative nausea and vomiting. Twenty-one randomised trials, including 1309 patients, were identified. Pain scores at rest at two postoperative hours were lower in the dexmedetomidine group, with a mean difference (95%CI) of −0.7 (−1.2 to −0.2), I² = 85%, p = 0.004, and a moderate quality of evidence. Secondary pain outcomes were also significantly better in the dexmedetomidine group. Rates of hypotension, shivering and postoperative nausea and vomiting were at least twice as frequent in patients who received remifentanil. Time to analgesia request was longer, and use of postoperative morphine and rescue analgesia were less, with dexmedetomidine, whereas episodes of bradycardia were similar between groups. There is moderate evidence that intra-operative dexmedetomidine during general anaesthesia improves pain outcomes during the first 24 postoperative hours, when compared with remifentanil, with fewer side effects.     

Anaesthesia for obstetricians

Anaesthesia and the anaesthetist have an important contribution to make to the provision of safe and effective maternity care. This is particularly relevant for current obstetric practice which is providing care to an older obstetric population with an increasing incidence of co-morbidities. In this review, the role of the anaesthetist in maternity care is described and the issues for providing anaesthesia and analgesia to pregnant women are discussed.     

瑞芬太尼痛觉过敏的预防及治疗研究进展

瑞芬太尼是临床麻醉中应用广泛的阿片类药物，具有起效快、半衰期短、无蓄积等优点，但瑞芬太尼痛觉过敏发生率高，且目前尚无有效的预防和治疗措施。本文阐述了近年来预防和治疗瑞芬太尼痛觉过敏的药物、方法及其作用机制。     

瑞芬太尼联合七氟烷麻醉对患者术后认知功能的影响

目的探讨瑞芬太尼联合七氟烷麻醉对术后患者认知功能的影响。方法 86例择期行腹腔镜手术的女性患者根据麻醉方法分为观察组和对照组,每组43例。对照组患者给予瑞芬太尼麻醉,观察组患者给予瑞芬太尼联合七氟烷麻醉;比较2组患者的生命体征、苏醒时间及认知功能。结果麻醉前、麻醉1 h、麻醉2 h及麻醉结束时2组患者的收缩压、舒张压、心率、呼吸频率及动脉血氧饱和度比较差异均无统计学意义(P>0.05)。观察组和对照组患者苏醒时间分别为(12.6±3.4)、(28.4±2.5)min,观察组患者苏醒时间显著短于对照组(P<0.05)。2组患者麻醉前简易精神状态量表(MMSE)评分比较差异无统计学意义(P>0.05);麻醉结束后6、12 h,观察组患者MMSE评分显著高于对照组(P<0.05);麻醉结束后24 h,2组患者MMSE评分比较差异无统计学意义(P>0.05)。麻醉前2组患者词语记忆能力、简单计算能力及图片再认能力评分比较差异无统计学意义(P>0.05);2组患者麻醉结束后12 h图片再认能力评分与麻醉前比较差异无统计学意义(P>0.05);2组患者麻醉结束后12 h词语记忆能力、简单计算能力评分均低于麻醉前(P<0.05);麻醉结束后12 h,观察组患者词语记忆能力和简单计算能力评分显著高于对照组(P<0.05)。结论瑞芬太尼联合七氟烷麻醉可显著改善患者术后认知功能。     

不同麻醉方式对腹腔镜全子宫切除2型糖尿病患者细胞免疫及血清炎症因子水平的影响

目的 探讨不同麻醉方式对腹腔镜全子宫切除2型糖尿病（T2DM）患者细胞免疫及血清炎症因子水平的影响。方法 选取2016年1月—2019年1月邯郸市中心医院收治的120例拟行腹腔镜全子宫切除术的T2DM患者,采用随机数字表法分为A、B组,每组60例。A组采用靶控输注丙泊酚和瑞芬太尼全身麻醉,B组在A组基础上复合吸入七氟醚全身麻醉。比较两组T淋巴细胞（CD3⁺、CD4⁺及CD8⁺）、NK细胞（CD3^-CD16⁺CD56⁺）、血清白细胞介素-6（IL-6）、超敏C反应蛋白（hs-CRP）、降钙素原（PCT）、IL-10水平及术中不良反应。结果 两组麻醉前（T₀）、建立气腹前（T₁）、建立气腹后90 min（T₂）、术后第1天（T₃）及术后第3天（T₄）CD3⁺、CD4⁺、CD8⁺、CD3^-CD16⁺CD56⁺和IL-6、hs-CRP、PCT、IL-10水平比较,在不同时间、不同组间及变化趋势上有差异（P <0.05）。B组苏醒时间、拔管时间短于A组（P <0.05）。两组麻醉维持时间、术中恶心呕吐、牵拉反应及低血压发生率比较,差异无统计学意义（P >0.05）。结论 靶控输注丙泊酚和瑞芬太尼复合七氟醚吸入全身麻醉可降低全子宫切除术T2DM患者围手术期血清炎症因子水平,保护细胞免疫功能,且不增加术中不良反应,具有一定的临床应用价值。     

Increased Tidal Volume Variability in Children is a Better Marker of Opioid-Induced Respiratory Depression than Decreased Respiratory Rate

OBJECTIVE: During opioid administration, decreasing respiratory rate is typically used as a predictor of respiratory depression. Prior to opioid-induced apnea, progressively irregular breathing patterns have been noticed. We hypothesize that opioid administration to children will increase tidal volume variability (TV(var)) and that this will be a better predictor of respiratory depression than a decrease in respiratory rate. METHODS: We recruited 32 children aged 2-8 years scheduled to undergo surgery. During spontaneous ventilation, flow rates and respiratory rates were continuously recorded, while remifentanil was infused at stepwise increasing doses each lasting 10 min. The infusion was continued until the patient showed signs of respiratory depression. Flow data from each dose was used to calculate tidal volumes, from which TV(var) was calculated. The respiratory rate and TV(var) during the last (D(last)), second to last (D-2), and third to last (D-3), administered doses were compared to those during baseline (fourth to last dose). We chose a threshold of TV(var) increase and compared it to a decrease in respiratory rate below 10 breaths per min as predictors of respiratory depression. RESULTS: Compared to baseline, the TV(var) increased by 336% and 668% during D(-2) and D(last), respectively, whereas respiratory rate decreased by 14.3%, 31.7%, and 55.5% during D(-3), D(-2), and D(last), respectively. A threshold increase in TV(var) of 150% over baseline correctly predicted respiratory depression in 41% of patients, compared to a drop in respiratory rate correctly predicting 22% of patients. CONCLUSIONS: TV(var) increases as children approach opioid-induced respiratory depression. This is a more useful predictor of respiratory depression than a fall in respiratory rate because the TV(var) increase is 10 times the drop in respiratory rate. A TV(var) increase also correctly predicts respiratory depression twice as often as decreased respiratory rate and is independent of age-related alterations in physiologic respiratory rates.     

瑞芬太尼和氯胺酮静脉麻醉用于重睑术的效果比较

目的：比较瑞芬太尼复合异丙酚和氯胺酮复合异丙酚在重睑成形手术中的静脉镇痛、镇静效果及清醒时间、手术时间和不良反应的发生率。方法：选择200例ASAⅠ-Ⅱ级择期行重睑成形术患者,随机分为A、B两组各100例。A组：瑞芬太尼复合异丙酚;B组：氯胺酮复合异丙酚。分别以瑞芬太尼复合异丙酚或氯胺酮复合异丙酚缓慢静脉推注,观察记录两组患者在入室麻醉前（t0）、静脉麻醉后即刻（t1）、局部浸润麻醉后即刻（t2）、局部浸润麻醉后5min（t3）、局部浸润麻醉后10min（t4）、局部浸润麻醉后20min（t5）时的心率（HR）、收缩压（SBP）、舒张压（DBP）变化情况及脉搏血氧饱和度（SpO2）,并记录两组患者的静脉麻醉镇痛与镇静效果、清醒时间、手术时间以及术中与术后恶心呕吐、呼吸抑制及躁动等不良反应。结果：A组患者静脉麻醉后（t1）与麻醉前（t0）相比HR、SBP、DBP有所下降,但差异无统计学意义（P＞0.05）;B组患者静脉麻醉后（t1）HR、SBP、DBP较麻醉前（t0）有所升高,差异有统计学意义（P＜0.05）;t1、t2、t3、t4节点B组HR、SBP、DBP均明显高于A组,两组差异有统计学意义（P＜0.05）;两组患者的静脉麻醉镇痛、镇静效果均很好,差异无统计学意义（P＞0.05）;A组与B组清醒时间分别为（6.5±2.2）min、（25.1±4.5）min,差异有统计学意义（P＜0.05）;A组与B组手术时间分别为（50.1±9.7）min、（83.4±11.5）min,差异有统计学意义（P＜0.05）;A组不良反应、并发症低于B组,差异有统计学意义（P＜0.05）。结论：瑞芬太尼与异丙酚静脉复合麻醉用于重睑成形术对患者的心血管刺激小,血流动力学影响小、并发症少;患者清醒时间、手术时间均较氯胺酮复合异丙酚麻醉时间短。总之,瑞芬太尼与异丙酚静脉复合麻醉用于重睑成形术效果优于氯胺酮复合异丙酚麻醉。     

Non-neuraxial analgesia in labour

Pain in labour is often described as one of the most severe pains experienced. Neuraxial techniques provide the most effective form of labour analgesia. However, not all women wish to have this or indeed want complete pain relief in labour. There are also subgroups of women in whom neuraxial techniques are contraindicated or attempted placement is unsuccessful. Therefore delivery units must be able to offer a range of non-neuraxial analgesia options for labour.