Adjuvant agents in regional anaesthesia

The addition of adjuvant agents to intrathecal and epidural anaesthetic techniques is well established, in particular opioids and clonidine. These adjuvants are utilized to improve the quality of anaesthesia and analgesia. Several other adjuvants have been studied but ongoing concerns surrounding safety and efficacy may limit their use in clinical practice. Epinephrine has for many years been administered in combination with local anaesthetic although more recently a diverse range of adjuvants have been added to peripheral nerve block solutions, again with the aim of prolonging surgical anaesthesia. The evidence to support or refute the benefit of these agents is increasing, as is our understanding of which agents have demonstrable efficacy and safety at clinically appropriate doses. Clinicians must be aware that many adjuvants are not licensed for central neuraxial or perineural use and should be aware of the risks, in particular of neurotoxicity and unwanted side effects.     

The association between caudal block and urethroplasty complications of distal tubularized incised plate repair: experience from a South China National Children’s Medical Center

BackgroundThe effect of caudal block (CB) on the incidence of urethroplasty complications in hypospadias repair remains controversial. The evidence is conflicting, and some confounding bias issues need to be addressed. We sought to study a more homogenous group of distal hypospadias patients undergoing primary tubularized incised plate (TIP) repair by a senior pediatric urology surgeon in the past 2 years to examine the relationship between urethroplasty complications and the use of CB.MethodsWe reviewed our database to identify consecutive patients who had undergone hypospadias repairs by a senior director surgeon at our Center between January 2018 and November 2020. To be eligible to participate in the study, patients had to meet the following inclusion criteria: (I) have distal hypospadias; (II) have undergone a primary TIP repair; and (III) have attended follow-up appointments for a minimum period of 6 months. The primary outcome was the development of urethroplasty complications during the follow-up period. The principal variable of interest was whether or not CB was used perioperatively. The patients were categorized into a CB group (general anesthesia combined with CB) or a control group (general anesthesia only). Other potential risk factors were analyzed, including patient age at operation, patient weight, glans width, and the length of the urethral plate defect.ResultsThirty (12.2%) of the distal patients developed postoperative surgical complications. The postoperative surgical complication rates were similar between the different anesthesia groups. Weight, the length of the urethral plate length, and glans width did not contribute to the risk. Age was the only independent risk factor for postoperative surgical complications, and the complication rates increased in older patients.ConclusionsOur data from consecutive TIP repairs in distal hypospadias patients indicated no association between the use of CB anesthesia and the postoperative urethroplasty complication rate. Patients who were older in age when they underwent surgery had a higher risk of complications.     

新生儿体重与优生─附13140例分析

回顾性分析了１２年来１３１４０例新生儿体重及相关因素。新生儿初生体重由１９８２年的３０５０±５７６ｇ上升至１９９３年的３３１７±４２９ｇ。低体重儿发生率由６．４％降至２．９％。大胎儿的发生率由１７．８％升至３１．８％。大胎儿剖宫产率、产后出血、新生儿窒息及第二产程延长的发生率均明显高于正常体重儿。提出预防低体重儿和大胎儿并重的原则。     

Ca2+ channel actions of the non-dihydropyridine Ca2+ channel antagonist Ro 40-5967 in vascular muscle cells cultured from dog coronary and saphenous arteries

Summary We studied the membrane effects of (1S,2S)-2-(2-[[3-2(benzimidazolyl) propyllmethylamino]ethyl)-6-fluoro-1,2,3,4-tetrahydro-l-isopropyl-2-naphthyl-methoxy-acetate dihydrochloride, Ro 40-5967, a new non-dihydropyridine (DHP) Ca²⁺ channel antagonist, on dog coronary and saphenous arterial vascular muscle cells using the whole-cell patch-clamp method. Long-lasting (L-type) inward currents in 20 mM Ba²⁺ were measured over a range of test potentials (300 ms) from –50 mV to + 90 mV from a holding potential of –80 mV in the presence of 1 M Bay k8644 (a DHP Ca²⁺ agonist). Ro 40-5967 caused a concentration-dependent suppression of Ca²⁺ channel currents in muscle cells from both arteries, with greater potency on coronary than saphenous arterial cells. The concentration of Ro 40-5967 which inhibited the magnitude of peak inward currents by 50% (IC₅₀) was estimated to be 1 M (n = 5) in muscle cells from coronary artery and 10 M (n = 4) in saphenous artery. Ro 40-5967 (1 M) decreased the amplitude of the activation current-voltage relationship for coronary L-type Ca²⁺ channel currents over a wider range of membrane potentials than verapamil, diltiazem, or nifedipine. In contrast, block of Ca²⁺ channel currents in saphenous artery cells by 1 M Ro 40-5967 was only observed at command potentials positive to 0 mV. Ro 40-5967 (1 M) significantly shifted the voltage-inactivation curve downward by 40% in coronary (n = 4), but only by 18% in saphenous arterial muscle cells (n = 3). The non-parallel shift of the coronary artery inactivation curve suggests that pronounced resting channel block is a notable feature of Ro 40-5967. The marked inhibition of Ba²⁺ current by 1 M Ro 40-5967 in the inactivation protocol in coronary arterial muscle cells was found over the entire range of membrane holding potentials tested, while inhibition in the saphenous artery inactivation curve occurred only from holding potentials more positive than –40 mV. Therefore, Ro 40-5967 is unique: 1) in acting over a wider range of voltages, on both instantaneous and resting Ca²⁺ currents, than other Ca²⁺ antagonists; 2) in producing more significant resting state block; and 3) in acting with selectivity for coronary over saphenous arteries.This research was supported by National Institutes of Health grants HL38537, HL38645, and by F. Hoffmann-La Roche, Basel, Switzerland     

聋哑儿童听力语言训练探讨

报告对138例聋哑儿童的语言训练,其中,男85例,女53例,先天性聋哑20例,后天性聋哑118例,5岁以下聋哑者125例。认为主要是利用感觉途径的训练方法,叫作“多感觉方法”,即“看,听,摸”。作者体会聋童语言训练是否成功,家长是一个很重要的决定因素。对于聋童做好早期诊断,及时矫治是防哑的关键。     

改良的颈神经丛阻滞麻醉的临床观察

目的：探讨甲状腺大部切除手术应用改良的颈神经丛阻滞麻醉效果。方法：全部病例均采用一点法深浅颈神经丛阻滞。将全部病例随机分为A、B两组（每组30例）,深丛均为0.25%布比卡因液或1.14%利多卡因和0.14%地卡因混合液,每侧各约5-6ml。A组为与深丛相同浓度的局麻药液,每侧约8-10ml,B组为与A组所用药同等剂量,但其浓度为A组的2/3（即加入1/3容量的生理盐水）,使浅丛容量较A组增加1/3,约为11-13.5ml。结果：两组病人经过顺利,均无并发症。阻滞效果均较好,但A组病人在手术进行到牵拉甲状腺上极时,有12例病人牵拉痛较明显。结论：低浓度高容量法颈丛阻滞,效果可靠、安全、并发症少,是甲状腺大部切除较理想的麻醉方法。     

新生儿缺氧缺血性脑病血浆及脑脊液一氧化氮水平的变化

目的 :了解新生儿缺氧缺血性脑病 (HIE)时血浆和脑脊液 (CSF)中 NO水平的动态变化。方法 :采用硝酸根还原酶法 ,对 35例 HIE患儿 (轻度 10例、中度 13例、重度 12例 )分别于急性期、恢复期进行了血浆和 CSF NO水平测定。结果 :HIE急性期血浆 NO水平除轻度组外 ,中、重度组明显高于对照组 ,重度组又明显高于轻、中度组 ;恢复期轻、中、重度组血浆 NO水平均降至正常 ,与对照组比较差异无显著性。CSF中 NO水平增加的幅度与血浆成正比。结论 :血浆和 CSF中 NO水平与 HIE的脑损伤程度密切相关     

A comparison of perinatal mortality between ethnic Chinese and ethnic whites: Why the Chinese rate was lower

Objectives. To confirm the observation that has been occasionally reported in the literature that perinatal mortality rate is lower in ethnic Chinese than in ethnic whites, and to assess the reasons for this lower perinatal mortality rate.

Methods. Secondary‐analysis based on published data.

Results. This exercise demonstrates that the perinatal mortality rate was lower in ethnic Chinese than in ethnic whites. The birth weight distribution in ethnic Chinese was more favourable with reduced births at two extremes of the distribution, and the exposure to risk factors for perinatal death by their mothers was also lower.

Conclusion: Perinatal mortality rate is lower in ethnic Chinese than in ethnic whites, and the lower perinatal mortality rate in ethnic Chinese is probably caused by their favourable birth weight distribution and lower exposure to risk factors of perinatal death by their mothers.     

Comparison of the acute cardiotoxicity of the antimalarial drug halofantrine in vitro and in vivo in anaesthetized guinea-pigs

1. Several unrelated drugs have pro-arrhythmic activity associated with an ability to prolong the QT interval of the ECG. The aim of this work was to examine the effects of the antimalarial drug halofantrine in vivo and in vitro.
2. In anaesthetized guinea-pigs consecutive bolus doses of halofantrine (0.3, 1, 3, 10 and 30 mg kg⁻¹, i.v.) at 25 min intervals caused dose-dependent prolongation of the rate corrected QTc interval and bradycardia. The change in heart rate became significant after administration of 10 mg kg⁻¹ halofantrine (−23±9 beats min⁻¹) whereas the increase in QTc was significant with only 1 mg kg⁻¹ halofantrine (22±10 ms). It was only with the highest dose of halofantrine that the PR interval was increased (from 52±3 to 67±4 ms) and second degree atrioventricular (AV) block (type 1 Mobitz) occurred in all animals. No changes were observed in any parameters in a separate group of guinea-pigs which received vehicle (dimethylacetamide 60% propylene glycol 40%) at equivalent time points.
3. The blood concentrations of halofantrine ranged from 0.26±0.17 μM after administration of 0.3 mg kg⁻¹ to 2.79±0.87 μM after 30 mg kg⁻¹, i.v. There was a significant correlation between the blood concentrations of halofantrine and the changes in QTc interval.
4. In guinea-pig left papillary muscles the effective refractory period was increased significantly 60 min after addition of halofantrine; from 161±4 to 173±6 ms with 10 μM, 156±8 to 174±6 ms with 30 μM and 165±6 to 179±5 ms with 100 μM halofantrine. However, the vehicle (0.1% Tween 80 in DMSO; final concentration of vehicle in Krebs, 1%) also increased the effective refractory period from 164±5 to 173±6 ms. Similar results were obtained in right ventricular strips but left atrial effective refractory periods were not altered by either the vehicle or halofantrine.
5. The results of these experiments suggest that any direct effects that halofantrine may have had on the effective refractory period of cardiac muscle cannot be separated from those of the vehicle. The prolongation of QTc and consistent observation of AV block with halofantrine in anaesthetized guinea-pigs suggest that in vivo models may be more useful for further studies investigating the mechanisms underlying the cardiotoxicity of halofantrine.