High frequency jet ventilation for microlaryngeal laser surgery

The use of a triple lumen central venous catheter, which can be shielded from laser irradiation by metal tape, as a conduit for high frequency jet ventilation in six children, is described. The problems of anaesthesia for laryngeal laser surgery and the advantages of the technique described in this paper are discussed.     

Cardiovascular responses to insertion of the laryngeal mask

We have compared, in 40 healthy patients, the cardiovascular responses induced by laryngoscopy and intubation with those produced by insertion of a laryngeal mask. Anaesthesia was induced with thiopentone and maintained with enflurane and nitrous oxide in oxygen; vecuronium was used for muscle relaxation. Arterial pressure was measured with a Finapres monitor. The mean maximum increase in systolic arterial pressure after laryngoscopy and tracheal intubation was 51.3% compared with 22.9% for laryngeal mask insertion (p less than 0.01). Increases in maximum heart rate were similar, (26.6% v 25.7%) although heart rate remained elevated for longer after tracheal intubation. We conclude that insertion of the laryngeal mask airway is accompanied by smaller cardiovascular responses than those after laryngoscopy and intubation and that its use may be indicated in those patients in whom a marked pressor response would be deleterious.     

听神经瘤的MRI诊断(20例报告)

回顾分析了20例22个听神经瘤的MRI表现。MRI检查采用0.35T超导MT/S成像系统,常规行冠状面T_1加权及横断面T_(1-)T_2加权成像。据瘤体大小将病灶分成4组,包括限于内听道者1例,1-2cm者2例,2.1-3cm者8例,大于3cm者11例,结果表明,T_1加权像对听神经瘤的诊断价值较大,主要依据是CP角内出现与听神经根部相连的肿块或听神经明显增粗;大于2cm的听神经瘤多可发生囊变、出血及脑干、Ⅳ脑室受压。除可发现位于内听道内的微小肿瘤外,MRI在肿瘤囊变、出血、周围结构受压情况、肿瘤供血血管及肿瘤与周围粘连情况的显示上均具有一定的优越性。     

INVOLVEMENT OF NON-NMDA AND NMDA RECEPTORS IN GLUTAMATE-INDUCED PRESSOR OR DEPRESSOR RESPONSES OF THE PONS AND MEDULLA

1. Fifty-five intact and six baroreceptor denervated and vagotomized cats of either sex were anaesthetized intraperito-neally with urethane (400 mg/kg) and a-chloralose (40 mg/kg). Responses of the systemic arterial pressure (SAP), mean SAP (MSAP) and sympathetic vertebral nerve (VNA) and renal nerve activities (RNA) were recorded. 2. In intact animals, monosodium L-glutamate (Glu, 0.1 mol/L, 50 nL) was microinjected into pressor areas of the locus coeruleus (LC), gigantocellular tegmental field (GTF), rostral ventrolateral medulla (RVLM) and dorsomedial medulla (DM), and the depressor areas of caudal ventrolateral medulla (CVLM). The induced actions were compared before and after microinjection of either glutamate antagonists, glutamate diethylester (GDEE, 0.5 mol/L, 50–100nL), a competitive AMPA receptor blocker, or 2-amino-5-phosphonovaleric acid (D-AP5, 0.025 mol/L, 50–100 nL), a competitive N-methyl-D-aspartate (NMDA) receptor blocker. GDEE completely blocked the increases of SAP and VNA elicited from all pressor areas. D-AP5 only partially blocked the pressor but slightly blocked VNA and RNA responses from LC, GTF and DM, particularly those from RVLM. Neither GDEE nor D-AP5 blocked the depressor responses of SAP and two nerve activities elicited from CVLM. 3. In baroreceptor denervated animals, NMDA (2 mmol/L, 50–100 nL) and AMPA (0.2 mmol/L, 50–100 nL) were micro-injected into the same pressor areas of GTF, RVLM and DM and the depressor area of CVLM responsive to Glu activation (0.1 mol/L, 30 nL). In RVLM, DM and CVLM, the results of either NMDA or AMPA were similar to those induced by Glu. However, in GTF, microinjection of either NMDA or AMPA did not induce similar responses to Glu. This suggests that the nature of GTF may differ from RVLM and DM. 4. The above results suggest that the Glu-induced pressor responses from LC, GTF, DM and especially RVLM, are primarily mediated through AMPA receptors. The Glu-induced depressor responses from CVLM may not be predominantly mediated by either AMPA or NMDA receptors. 5. In both baroreceptor-intact and -denervated cats stimulation of the pressor areas often produced an increase of VNA and a decrease of RNA, while in the depressor CVLM decreased both VNA and RNA. The VNA, but not RNA were positively correlated with the pressor responses, while both VNA and RNA were positively correlated with the depressor responses. This may suggest that neurons of the sympathetic vertebral and renal nerves are topographically organized in the brain.     

Calcitonin gene-related peptide-like immunoreactivity, in botulinum toxin-paralysed rat muscles

Changes in calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) at the motor endplates of botulinum toxin-paralysed rat muscles were investigated using immunohistochemistry. One day following toxin injection, a dramatic increase in CGRP-LI was detected at the motor endplates and within preterminal axons of the soleus and gastrocnemius muscles. The upregulation of CGRP-LI persisted throughout the period during which muscle fibres were paralysed and new neuromuscular junctions were being formed by the growing sprouts. Decline of CGRP-LI at the motor endplates coincided with clinical recovery. Both up- and down-regulation of CGRP-LI took place earlier in the soleus than in the gastrocnemius muscle. Up-regulation of CGRP-LI was also detected in a subpopulation of motor axons in the sciatic nerves and in the spinal motor neurons innervating the paralysed muscles. These results indicate that levels of CGRP are regulated, at least partly, by changes in the target innervation. They also suggest an important role for CGRP in the regenerative processes following muscle paralysis.     

星状神经节阻滞对炎症痛兔血清皮质醇和炎症局部β-内啡肽的影响

目的 :观察星状神经节阻滞 (SGB)对福尔马林炎症痛家兔血清皮质醇 (CS)和炎症局部 β -内啡肽 (β -EP)含量的影响。方法 :选择健康家兔 1 6只 ,随机分为SGB组和对照组 ,各 8只。两组均用 8%福尔马林 0 .5ml在右前肢足底皮下注射致痛 ,致痛前 1 0minSGB组经预置导管给 0 .2 5 %布比卡因 0 .5ml,对照组给等量生理盐水。用放免法测定致痛前 1 0min(T0 )、致痛后 1 0、60和 1 2 0min(T1 、T2 和T3)血清CS及致痛 1 2 0min炎症局部 β-EP含量。结果 :致痛后对照组血清CS在各时点均较致痛前升高 ,且在T2 时达高峰 (P <0 .0 1 ) ,而SGB组各时点较致痛前无明显差异 (P >0 .0 5) ;两组相比 ,T0 时无差异 (P >0 .0 5) ,而在T1 、T2 和T3时有明显差异 (P <0 .0 5 ,P<0 .0 1 )。SGB组致痛后 1 2 0min时炎症局部 β -EP含量明显高于对照组 (P <0 .0 1 )。 结论 :SGB可抑制福尔马林刺激引起的血清CS的升高 ,并且可增加炎症局部 β-EP含量     

带血管蒂前臂后皮神经电缆式移植修复上臂桡神经缺损

目的：介绍带血管蒂前臂后皮神经电缆式移植修复上臂桡神经缺损的应用解剖、手术方法及临床效果。方法：在２０侧成人上肢标本上，观测前臂后皮神经及桡侧副动脉的行程及外径，设计以桡侧副动脉为蒂的前臂后皮神经电缆式移植修复上臂桡神经缺损的新术式并应用于临床。结果：前臂后皮神经与桡侧副动脉伴行关系密切，具有形成带血管蒂前臂后皮神经转移的解剖学条件；前臂后皮神经横径２．０ｃｍ左右，可切取长度１５．０ｃｍ左右，折叠后可以修复７．０ｃｍ左右的桡神经缺损。同时，术中发现神经供体断端出血活跃，说明带血供的前臂后皮神经移植的血供是可靠的。临床应用８例，神经缺损３．５～６．０ｃｍ，随访１０个月～３年，效果满意。按陆裕朴介绍的评定标准：优４例，良３例，可１例。结论：该术式转移灵活，操作简单、安全、可靠，对供区影响小，是修复上臂桡神经缺损的一种有用的方法。     

A Comparative Study of the Percutaneous versus Intraoral Technique for Mental Nerve Block

Objective: Mental nerve block is frequently used to aid repair of facial lacerations; both percutaneous and intraoral approaches to blocking this nerve are used, but have never been compared. The authors compared the two techniques for pain of administration and effectiveness of anesthesia. Methods: A prospective, randomized, single-blind, crossover study was conducted using ten healthy volunteers aged 22 to 33 years. Patients having prior experience with mental nerve blocks, lidocaine allergy, active oral/facial infection, or previous facial fractures were excluded. Bilateral mental nerve blocks were done using intraoral technique on one side and percutaneous technique on the other. Both techniques were used by the same investigator and were carried out with 27-gauge needles and 2.5 mL of 2% buffered lidocaine at room temperature injected over 20 seconds. The oral mucosa was topically anesthetized with viscous lidocaine for 1 minute prior to intraoral injection. The orders of the blocks and sides of the face anesthetized were randomized. Subjective and objective pain (visual-analog scale), efficacy (anesthesia of lower lip), time to onset, and duration of anesthesia were evaluated. Results: The intraoral technique was subjectively less painful than the percutaneous approach in nine of ten subjects (p = 0.02). Scores on the visual-analog pain scale were significantly lower for the intraoral technique (p = 0.03). Intraoral injection produced lower-lip anesthesia in 10/10 subjects versus 7/10 for percutaneous (p = 0.25). Times to onset (approximately 1–2 minutes) and durations of anesthesia (approximately one hour) were similar for the two techniques. Conclusion: The intraoral approach to the mental nerve block with adjunctive topical anesthesia was subjectively and objectively less painful than the percutaneous approach without adjunctive anesthesia. While the intraoral approach had a greater efficacy of lower-lip anesthesia and a longer duration of action, these differences were not statistically significant.