Cholinergic hyperactivity in patients with myasthenia gravis with MuSK antibodies: A neurophysiological study

ObjectivePatients with myasthenia gravis associated with muscle-specific tyrosine kinase antibodies (MuSK-MG) often manifest signs of cholinergic hyperactivity with standard doses of acetylcholinesterase inhibitors (AChE-Is). Aim of the study was to investigate whether repetitive compound muscle action potential (R-CMAP), the neurophysiological correlate of cholinergic hyperactivity, was present in MuSK-MG irrespective of AChE-I treatment.MethodsPatients with confirmed diagnosis of MuSK-MG were consecutively enrolled during follow-up visits, from January 2019 to April 2020. All these subjects underwent the same neurophysiological protocol, including motor nerve conduction studies and repetitive nerve stimulation. In patients taking pyridostigmine, neurophysiological testing was performed at least 12 hours after the last dose. For comparison, the presence of R-CMAP was investigated in 20 consecutive acetylcholine receptor antibody positive myasthenia gravis (AChR-MG) patients.ResultsWe enrolled 25 MuSK-MG patients (20 females), aged 16–79 years at the study time, with disease duration ranging 0.6–48.8 years (median: 17.7 years). R-CMAP was detected in 12/25 (48%) MuSK-MG cases and in none of the AChR-MG controls (p = 0.0003). In the MuSK-MG population, a history of muscle cramps and fasciculations, during low-dose pyridostigmine therapy, was significantly more frequent in R-CMAP positive than in R-CMAP negative patients (100% vs 31%, p = 0.001). At the time of the study, the proportion of patients still symptomatic for MG was higher among R-CMAP positive cases (92% vs 23%, p = 0.0005).ConclusionsCholinergic hyperactivity is a relatively common finding in MuSK-MG patients, independent of AChE-I treatment, and may constitute an intrinsic feature of the disease.SignificanceR-CMAP detection can represent a useful diagnostic clue for MuSK-MG and predicts poor tolerance to AChE-Is.     

髋部骨折术后物理措施预防血栓形成的有效性分析

目的探讨髋部骨折围手术期物理措施预防血栓形成的有效性和安全性。方法把96例符合条件的患者分为A和B两组,A组术后应用物理措施预防血栓形成,B组术后应用低分子肝素钙预防血栓形成,通过对比两组深静脉和肺栓塞的发生率及出血性并发症的发生率,比较两组治疗措施的效果。结果 A组48例物理措施预防血栓形成的患者血栓形成的发生率为8.33%,出血性并发症的发生率为2.08%;B组48例应用低分子肝素钙血栓形成的发生率为6.25%,出血性并发症的发生率为4.17%。结论在髋关节骨折术后中单独应用物理措施预防血栓形成的效果并不比单独应用低分子肝素差。     

不同模式正压面罩通气在腹腔镜胆囊切除术患者麻醉诱导中的比较

目的 比较腹腔镜胆囊切除术患者麻醉诱导中三种不同正压面罩通气模式对胃肠胀气的影响以及通气变量的变化,从而选择良好的通气模式,减少面罩通气的不良影响.方法 选择择期行腹腔镜胆囊切除术患者60例,ASA分级为Ⅰ～Ⅱ级,根据麻醉诱导过程中采用不同通气方式分为3组,每组20例,分别为压力控制模式(PVC)组,容量控制模式(VCV)组,手动控制模式(MCV)组,呼吸及血流动力学参数采用麻醉机及其监护仪监测,胃内气体监测采用建立气腹后腹腔镜直视下由有经验麻醉医师判断是否有胃肠胀气,麻醉诱导及其判断是否胀气者为不同麻醉医生,并采用双盲法.结果 3组血流动力学参数差异无统计学意义,而PVC组气道压力明显低于VCV及MCV组,PVC组发生胃肠胀气百分比明显低于VCV及MCV组.结论 压力控制模式是良好的通气模式.     

Screening for fetal chromosomal and subchromosomal disorders

Screening for fetal chromosomal disorders has evolved greatly over the last four decades. Initially, only maternal age-related risks of aneuploidy were provided to patients. This was followed by screening with maternal serum analytes and ultrasound markers, followed by the introduction and rapid uptake of maternal plasma cell-free DNA-based screening. Studies continue to demonstrate that cfDNA screening for common aneuploidies has impressive detection rates with low false-positive rates. The technology continues to push the boundaries of prenatal screening as it is now possible to screen for less common aneuploidies and subchromosomal disorders. The optimal method for incorporating cfDNA screening into existing programs continues to be debated. It is important that obstetricians understand the biological foundations and limitations of this technology and provide patients with up-to-date information regarding cfDNA screening.     

控制性降压下俯卧位脊柱手术全麻患者眼内压及眼底动脉血液动力学的变化

目的实时监测控制性降压对俯卧位脊柱手术全麻患者眼内压及眼底动脉血液动力学的影响,以探讨其安全阈值。方法随机选取预行俯卧位脊柱全麻手术的60例外科患者为研究对象,麻醉过程中采用硝酸甘油控制性降压。选择诱导前10 min(T0)、诱导后10 min(T1)、俯卧位后10 min(T2)、控制性降压10%(T3)、20%(T4)、30%(T5)、恢复正常血压10 min(T6)、术毕平卧位后10 min(T7)、拔出气管导管后10 min(T8)9个时间点,使用笔式眼压计测量眼内压(IOP),使用彩色多普勒超声仪测定右眼视网膜中央动脉和睫状后动脉的血流动力学特征收缩期最高流速(PSV)、舒张末期最低流速(EDV)、阻力指数(RI)及搏动指数(PI)。结果患者诱导麻醉后,IOP、RI及PI随着麻醉时间的延长呈升高趋势,PSV及EDV呈降低趋势,T5时,各指标差异性最大,均较T0有显著差异(P0.05或0.001)。T6后,各指标有所恢复,T8各指标较T0无统计学差异(P0.05)。另外,T5时4例患者出现视网膜中央动脉闭塞(CRAO)征象,其MAP均低于患者该时段平均水平(64.8±8.66 mmHg)。结论控制性降压对俯卧位脊柱手术全麻患者的眼内压及眼底动脉血液动力学指征有所影响,血压降低水平控制在基线水平的30%以内,且保证目标MAP65 mmHg,可有效保护患者视神经。     

New method of neck surface electromyography for the evaluation of tongue‐lifting activity

Elevation of the posterior part of the tongue is important for normal deglutition and speech. The purpose of this study was to develop a new surface electromyography (EMG) method to non‐invasively and objectively evaluate activity in the muscles that control lifting movement in the posterior tongue. Neck surface EMG (N‐EMG) was recorded using differential surface electrodes placed on the neck, 1 cm posterior to the posterior border of the mylohyoid muscle on a line orthogonal to the lower border of the mandible. Experiment 1: Three healthy volunteers (three men, mean age 37·7 years) participated in an evaluation of detection method of the posterior tongue lifting up movement. EMG recordings from the masseter, temporalis and submental muscles and N‐EMG revealed that i) N‐EMG was not affected by masseter muscle EMG and ii) N‐EMG activity was not observed during simple jaw opening and tongue protrusion, revealing the functional difference between submental surface EMG and N‐EMG. Experiment 2: Seven healthy volunteers (six men and one woman, mean age 27·9 years) participated in a quantitative evaluation of muscle activity. Tongue‐lifting tasks were perfor‐med, exerting a prescribed force of 20, 50, 100 and 150 gf with visual feedback. For all subjects, a significant linear relationship was observed bet‐ween the tongue‐lifting force and N‐EMG activity (P < 0·01). These findings indicate that N‐EMG can be used to quantify the force of posterior tongue lifting and could be useful to evaluate the effect of tongue rehabilitation in future studies.     

Central venous pressure and pulmonary artery pressure monitoring

Stroke volume is a key determinate of cardiac output. It is affected by the preload, contractility and afterload of the myocardium. It is possible to gain insight into the right and left ventricular preload following the insertion of a central venous catheter and pulmonary artery catheter to measure central venous pressure and pulmonary capillary wedge pressure, respectively. Abnormal measurements can indicate a pathophysiological state and guide management.     

Cesarean Scar Pregnancy: Comparing the Efficacy and Tolerability of Treatment with High-Intensity Focused Ultrasound and Uterine Artery Embolization

The aim of this study was to investigate the clinical efficacy of high-intensity focused ultrasound (HIFU) for the treatment of a cesarean scar pregnancy compared with uterine artery embolization (UAE) and intra-arterial methotrexate infusion combined with uterine curettage. In this retrospective cohort study, 31 patients were treated with HIFU (HIFU group), and 45 patients were treated with UAE (UAE group). We compared the treatment and recovery of the patients, including follow-up. After UAE treatment, serum levels of the β subunit of human chorionic gonadotropin declined significantly on the first day, and the residual lesions disappeared in 3–17 wk. One patient underwent hysterectomy; intrauterine adhesions were found by hysteroscopic examination after 6 mo in 2 patients, whose menstrual function did not return to normal. The remainder of the 42 patients recovered normal menstrual functioning during the 3- to 18-wk follow-up. In the patients who underwent HIFU treatment, serum β-HCG levels did not decline rapidly; serum β-HCG levels increased in many patients and then declined to normal steadily within 2–12 wk. Lesions detached in 3–14 wk in all patients, and menstrual functioning was recovered in 3–9 wk without uterine curettage. Compared with the UAE group, the HIFU group had less pain and fewer complications; the patients in the HIFU group were not hospitalized or anesthetized and had lower costs. HIFU is an efficient, tolerable and non-invasive treatment.