丁香园上陶教授发起的关于住院医基础问题

yinyilei

各位版主和许多战友比较关注麻醉学进展，经常介绍最新文献资料，使大家收益，在此感谢。

我在这里从另一个角度，也就是麻醉医师的基本功方面，开辟一个栏目。大家也许都能感觉到，书上内容很多，中文书条条框框很复杂，外文书滔滔不绝一大片。我科负责教育的 Dr. James Griffin 针对这个问题，把书上内容 “浓缩” 起来，做成卡片，分给住院医，实际上对主治医也是一个温故知新的作用。他的目的是让住院医生每日掌握一条信息。由于他讨论的几个问题，有连续性，我在这里把几个问题一起贴出，称其为 每周 一题。

我们这里学习的，不是高精尖技术，不是高级设备，也不是最新进展，更不是大师观点，而是住院医生的理念基本功。

第一次我来翻译。今后有战友愿意翻译，我可以协助。我有用词不当的，也欢迎大家指正。

本期题目为麻醉体位问题。看似简单，很多“资深”者也许会不屑一顾。但园子里有多少病人，麻醉后有神经症状的报道。手术中，体位是麻醉医生的职责。我们做到了科学地摆放病人的体位了吗？

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Nov 9 - Discuss hemodynamic & resp. effects of lateral decubitus positioning

侧卧位对呼吸和循环的影响：

Discussion points.

Placement of a patient in the lateral decubitus position can result in significant mismatching of pulmonary ventilation-to-perfusion during mechanical ventilation of the lungs for a number of reasons. First, while in the lateral position the mechanically ventilated patient has relatively better ventilation of the superior lung, while the dependent lung is being ventilated less. The reasons for the dependent lung being ventilated less are secondary to the loss of lung volume from compression by abdominal contents, mediastinal contents, and the structures used to position the patient. The patient concurrently has better perfusion of the dependent lung, primarily secondary to the effects of gravity. Together, these factors result in greater mismatching of ventilation and perfusion of the lungs during mechanical ventilation in a patient in the lateral decubitus position. Clinically, this may manifest as arterial hypoxemia.

Placement of a patient in the lateral decubitus position can result in compression of the inferior vena cava from the pressure of a kidney rest. This can lead to a decrease in venous return to the heart.

侧卧位可以因多种原因导致肺的通气／灌注比例失调：1，侧卧位患者机械通气时，其上肺通气相对较好，而下肺通气不好（注：文献中常把下肺称为 “依赖肺”dependent lung，我想其来源是，下肺是 “依赖重力的肺” weight-dependent lung 的缘故）。下肺通气不好的原因，是由于该肺受到腹腔内容物，纵隔，和固定病人体位的各类材料和结构挤压所致。在病人下肺通气不良的同时，其血流灌注又因为重力的作用有所增加。这两个因素加起来的结果，就是侧卧位通气病人通气／血流比例失调，临床表现为动脉缺氧。

侧卧位病人也可因腰垫（kidney rest）压迫下腔静脉，导致回心血量减少。

References. Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; p. 199; Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000; p. 578-582, 1686-1689.

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Nov 10 - Discuss upper extremity positioning in the lat. decubitus position

侧卧位时上肢体位摆放：

Discussion points.

An axillary roll properly placed under a patient in the lateral decubitus position supports the patient's chest and minimizes the risk of compression of the nerves and vessels in the axilla. The dependent brachial plexus may also be injured should the axilla be compressed sufficiently to compress the brachial plexus. Proper placement of the axillary roll is under the thorax caudad to the axilla. The radial pulse may be checked periodically intraoperatively as a gross measure of compression of the vessels in the axilla. Alternatively, a pulse oximeter may be placed on a finger of the dependent hand to ensure no compression of arteries has occurred.

腋窝卷（axillary roll）放在适当的位置，可以支持病人的胸廓，使胸廓抬高后，减少重力对腋窝神经和血管的压迫（注：从这点看，axillary roll 应该叫 chest roll）。低位的臂丛受压严重时，可以导致神经损伤。腋窝卷的正确使用方法，是放在腋窝的尾端的胸廓下。手术中，可定时查看病人的桡动脉脉搏，大致估计腋窝是否受压，也可以将血样饱和探头放在低位手的手指上，确认动脉没有受到压迫。

References. Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; p. 199; Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000; p. 1019-1021.

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Nov 11 - Discuss nondependent arm & lower ext. positioning in the lat. decub. position.

侧卧位手术时上面的上下肢摆放：

Discussion points.

The patient's legs while in the lateral decubitus position should be positioned such that the dependent leg is flexed at the knee and there is a pillow between the two legs. This helps to minimize stretch of the nerves of the dependent leg and distributes more evenly the weight of the legs, such that discrete pressure points are avoided. Indeed, there have been case reports of arterial insufficiency of the dependent leg of patients undergoing hip arthroplasty in the lateral position leading to the need for subsequent below-the-knee amputation.

The patient's nondependent arm while in the lateral decubitus position should be positioned on an elevated armboard or pillow above and in front of the patient's face. Alternatively, the arm may be suspended from a support bar that is well-padded. Both positions should limit the extension of the arm to less than 90 degrees at the shoulder.

病人侧卧位时，下方的下肢在膝关节位置弯曲，两腿间放一个枕头，这样可以减少下方肢体神经的牵拉，同时使双下肢的重量比较分散，避免明显的着力点。过去曾有报道髋关节置换术后，下方下肢动脉灌注不足，最终导致病人的膝关节下截肢的病例。

侧卧位手术时，位于上方的的上肢，可以放在一个抬高的小桌面上，或者病人前方的一个枕头上。也可以用侧柱悬挂，但悬挂装置需要很好的软垫。使用这两种方法，都要使上肢和肩膀的成角小于 90 度。

References. Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; p. 199; Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000; p.p 1019-1021.

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Nov 12 - Discuss potential complications of the sitting position for surgery

坐位手术可能的并发症

Discussion points.

The sitting position is most often used for neurosurgical procedures, especially in the posterior fossa. The advantages of the sitting position for posterior fossa craniotomies are improved surgical exposure, less required retraction of the brain, and facilitated jugular venous drainage leading to less bleeding.

Patients placed in the sitting position for a surgical procedure may become hypotensive, especially if hypovolemic. Additionally, patients may have decreases in cardiac output and cerebral perfusion pressures. Hypotension can be avoided by positioning the patient in gradual steps to allow for accommodation, by ensuring adequate hydration, and through the temporary administration of small doses of vasopressors.

The principal potential intraoperative complication of positioning a patient in the sitting position for surgery is a venous air embolism. Placing the head above the level of the heart during the procedure facilitates the entrainment of room air. Patients undergoing craniotomies are especially at risk, given that veins in the bony cranium do not collapse after being transected. TEE, procordial doppler and ETCO2 monitoring can be used to detect VAE.

坐位手术通常用于神经外科手术，特别是颅后窝手术。坐位手术的优点是暴露良好，脑组织牵拉少，颈静脉回流好，手术失血少。
作为手术的病人容易发生低血压，特别是容量不足时。病人也容易有心输出量减少，脑组织灌注压降低。通过慢慢改变体位，使病人逐步适应，保持容量，小剂量使用血管活性药物，可以避免低血压。
坐位手术的主要并发症使空气栓塞 （venous air embolism, VAE）。手术中，病人的头的位置高于心脏使空气更容易进入血管。开颅手术的患者危险更高，因为颅骨的静脉切开后不能塌陷。经食道超声，心前多普勒，潮末二氧化碳监测，可以用于检测到 VAE。

References. Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; pp. 199-200; Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000; pp. 1024, 1027-1029, 1903-1906.

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Nov 13 - Discuss peripheral nerve injury- mechanism, risk factors, response

外周神经损伤的机制，风险因素，和对策

Discussion points.

Peripheral nerve injuries have occurred in patients after regional anesthesia or sedation as well as general anesthesia. Injury occurring to a nerve intraoperatively is usually due to compression or stretching of the nerve. The injury usually sustained to the nerve is neurapraxic, which is a loss of function without corresponding anatomic injury. The risk of sustaining an intraoperative nerve injury can be minimized by carefully positioning patients and by using padding when and where appropriate. There is evidence to suggest that patients who experience intraoperative nerve injury may have preexisting conditions that made the injury unavoidable, even with proper positioning and padding.

Co-existing medical conditions that place a patient at an increased risk for a peripheral nerve injury include occupational trauma, congenital anomalies, cubital entrapment syndrome, hematomas, hypothermia, hypotension, prolonged tourniquet time, cigarette smoking, and diseases such as diabetes mellitus, vitamin deficiency, alcoholism, or cancer.

Neurologic consultation obtained early after a peripheral nerve injury manifests in the postoperative period may be useful in detecting between acute injury and chronic injury. This can be accomplished through nerve conduction velocity and electromyographic studies. Signs of denervation from acute nerve injury are detected by an electromyogram 18 to 21 days after the injury, emphasizing the importance of obtaining neurologic consultation before this time. It may also be useful to test the same nerve in the limb opposite the symptomatic one to exclude any preexisting nerve injury that is asymptomatic.

The usual recovery time from an intraoperative peripheral nerve injury is 3 to 12 months. In rare cases, injury can be permanent, particularly with stretch injury that results in disrupted axons.

外周神经在全麻，区域麻，和单纯镇静病人身上都会出现。手术当中出现的神经损伤多为压迫或牵拉所致。这样的神经损伤多为生理性／轻型失用型（neuropraxic）损伤，即神经功能的丧失但没有结构损伤。通过体位摆放中适当使用软垫尽量减少手术中神经损伤。有证据表明 ，手术当中有神经损伤的病人，有可能术前就有病情，这类患者即使术中有适当的体位和软垫，神经损伤也不可避免。

病人的其他疾病也可以使病人的神经损伤的风险加大，这些疾病包括职业受伤，先天畸形，尺神经卡压综合征，血肿，低温，低血压，止血带时间过长，抽烟，糖尿病，维生素缺乏，酗酒，和癌症。

术后早期发现神经损伤后，可及时请神经内科会诊，通过神经传导速度和肌电图检查，以了解损伤是急性还是慢性的。急性神经损伤，在18 － 21 天内，肌电图可以表现出组织失去神经控制的表现，说明在这个时间前获得神经内科会诊是很重要的。有时也可以通过检查对侧同一个神经，排除病人原来就有，而又无特别症状的神经损伤。

手术中发生的外周神经损伤的恢复时间一般为 3－12 个月。永久神经损伤，偶尔也可以见到，特别是神经损伤涉及到神经元的患者。

References. Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; pp. 202-203; Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000; p. 1029-1030.

yinyilei

谢谢各位的参与和鼓励。没想到还有学英语的作用。

辉plus 和 yecathy，我已经把下两周的内容发给了你们。

xiaolin_2009 和 120 提出的观察，也许很有道理：长时间在区域麻醉状态下，病人的紧张，或试图维持某一个体位，都有可能是患者肌肉处于等长收缩状态，手术后当然就很难受了。

yymelon 提出的问题，我在当住院医生时，有一次经历：一耳鼻喉科手术，大概 4 小时左右，病人到了 PACU 后，护士报告病人的脚后跟发红，很明显是后跟成为着力点压迫所致。护士要打报告，我说我的麻醉注意力在头部，脚后跟是巡回护士的事。结果主治来看后，说：“Positioning is anesthesia”，主动承担了责任。后来仔细想了一下，我也认为主治是对的：麻醉术上写了体位的摆放和频繁查看的必要，都是针对麻醉医生而言的，压力点保护，是我们的职责，这就是真正麻醉医生和 “麻一针” 之间的区别。有经验的护士，有很大的帮助，在一定程度上减轻了我们的工作量，但最终责任还是在我们自己身上。

这里上传几张图。顺时针方向，分别是：

大号 axillary roll （根据病人大小选用）；
脚后跟垫（撕开后也可以用来保护上肢），顺便显示一下序惯挤压袖带；
卧位手术用的枕头（上额和下颌在上下分别着力，鼻尖，眼睛要悬空，插管胃管从旁边伸出）；
空心枕头。
。

（缩略图，点击图片链接看原图）

yinyilei

Topic of the Day I(for Interns and CA-2’s)

Sept 28 - Discuss MOA of reversal agents used for antagonism of NM blockade

非去极化肌松药的药物拮抗原理

Discussion points.

The antagonism of the neuromuscular blockade produced by nondepolarizing neuromuscular blocking drugs is achieved through the intravenous administration of anticholinesterases. The anticholinesterases most often used for this purpose are neostigmine and edrophonium. These drugs exert their effect by inhibiting the activity of acetylcholinesterase, the enzyme that hydrolyzes acetylcholine in the neuromuscular junction. As a result of the inhibition of the hydrolysis of acetylcholine, acetylcholine accumulates in the neuromuscular junction. With more acetylcholine available at the neuromuscular junction the competition between acetylcholine and the nondepolarizing neuromuscular blocking drug is altered such that it is more likely that acetylcholine will bind to the postjunctional receptor. In addition to increasing the amount of acetylcholine available in the neuromuscular junction to compete for sites on the nicotinic cholinergic receptors, acetylcholine also accumulates at the muscarinic cholinergic receptor sites through the same mechanism.

静脉应用胆碱酯酶抑制剂可实现非去极化肌松药的拮抗。最常使用的胆碱酯酶抑制剂为新斯的明和依氯酚铵。这些药物通过抑制在神经肌肉接合部位水解乙酰胆碱的乙酰胆碱酯酶的活性而发挥效应。由于水解减少，在神经肌肉接合部位的乙酰胆碱水平升高。乙酰胆碱数量越多，越能与非去极化肌松药竞争结合接合部位后膜受体。基于同样的机理，应用胆碱酯酶抑制剂同时也会导致毒蕈碱胆碱能受体周围的乙酰胆碱水平升高。

References: Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; p. 104. Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000. pp. 466-467, 748-749.

Sept 29 - Discuss the muscarinic effects of anticholinesterase inhibitors

胆碱酯酶抑制剂的毒蕈碱效应

Discussion points.

Anticholinesterases increase the concentration of acetylcholine available at the muscarinic cholinergic receptors as well as the nicotinic cholinergic receptors. This may result in profound bradycardia through the stimulation of muscarinic cholinergic receptors in the heart. To attenuate the cardiac muscarinic effects of anticholinesterases, a peripheral-acting anticholinergic such as atropine or glycopyrrolate is administered intravenously before or simultaneous with the intravenous administration of the anticholinesterase.
和烟碱胆碱能受体一样，使用胆碱酯酶抑制剂后毒蕈碱胆碱能受体周围的乙酰胆碱水平升高。这可导致明显的心动过缓。为了减轻胆碱酯酶抑制剂的心脏毒蕈碱效应，可在使用胆碱酯酶抑制剂之前或同时静脉应用外源性抗胆碱能药物，如阿托品或格隆溴铵。



Sept 30 - Discuss factors that influence choice of anticholinesterase inhibitor

影响选择胆碱酯酶抑制剂的因素

Discussion points.

Two factors that influence the choice of anticholinesterase drug to be administered to antagonize neuromuscular blockade include the approximate duration of action of the nondepolarizing neuromuscular blocking drug that had been administered and the intensity of the neuromuscular blockade that exists at the conclusion of surgery.

影响选择胆碱酯酶抑制剂用于拮抗肌松的因素有二，一是非去极化肌松药的大致作用时间，二是术毕神经肌肉阻滞的程度。

References. Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; pp. 104-105. Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000; pp. 466-467.

Oct 1 - Discuss test to evaluate adequacy of recovery from NM blockade

神经肌肉阻滞恢复程度的评测方法

Discussion points.

Confirmation of the recovery from the effects of neuromuscular blockade that have occurred either spontaneously or through the administration of anticholinesterases should be obtained before extubation of the patient's trachea at the conclusion of general anesthesia. Often the mechanical muscle response to a train-of-four (TOF) stimulus is difficult for the clinician to evaluate manually or visually. When this is the case, the evaluation of the muscular response to a continuous tetanic stimulation may be useful. A sustained muscular contraction to a continuous tetanic stimulus usually indicates a TOF ratio greater than 0.7 and is an indication of adequate recovery from neuromuscular blockade.

Alternatively, a double burst suppression stimulus may be delivered by the peripheral nerve stimulator to facilitate the clinician's ability to evaluate the degree of fade.

Clinical tests that may also be used to evaluate the adequacy of the reversal of neuromuscular blockade include the patient's ability to open the eyes, cough, stick out the tongue, and sustain a head lift for 5 to 10 seconds; grip strength; vital capacity; and maximal inspiratory force. Of these clinical tests, a sustained head lift is considered to be the most sensitive test to evaluate the adequacy of the recovery from neuromuscular blockade.

在全身麻醉结束拔除气管导管前应该通过自发恢复或应用胆碱酯酶抑制剂来确认神经肌肉阻滞的恢复。判断神经肌肉功能的恢复，有时很难通过手的触觉或视觉获得的肌肉对四个成串刺激（TOF）的机械反应情况来实现。在这种情况下，评估肌肉对持续强直刺激的反应性可能有用。给予一个持续强直刺激能获得持续的肌肉收缩常提示TOF比率>0.7，即意味着神经肌肉阻滞已充分恢复。

另外一种有助于评估肌松药效消退的方法是采用外周神经刺激仪监测双重爆发刺激。

一些临床检测手段也可以用于评估神经肌肉阻滞的充分逆转，包括：睁眼，咳嗽，伸舌，持续抬头5~10s；握力；肺活量；最大吸气力。在所有的检测手段中，又以持续抬头的敏感性最高。


Oct 2 - Discuss pros/cons of spinal and epidural anesthetic techniques

脊髓麻醉和硬膜外麻醉的利与弊

Discussion points.

Some advantages of regional anesthesia include the provision of surgical anesthesia without affecting the state of consciousness of the patient, skeletal muscle "relaxation, and the lack of the need to manipulate the airway or mechanically ventilate the lungs. Spinal anesthesia when compared with epidural anesthesia takes less time to perform and has a quicker onset, provides for intense sensory and motor anesthesia, and may be of less discomfort to the patient. Epidural anesthesia when compared with spinal anesthesia has a decreased risk of a postdural puncture headache, allows for more control over the level of anesthesia and the duration of the anesthetic if prolonged anesthetic times are desired, may lead to better control of associated hypotension due to its slower onset, and provides for an indwelling catheter that can be used for acute postoperative pain management.
Fears patients may have about regional anesthesia include the fear of needlesticks in their backs and the fear of paralysis resulting from the administration of the anesthetic. Biases surgeons have against regional anesthesia stem from, among other things, their belief that the administration of regional anesthesia will delay the start of the case or will be inadequate for the procedure.

区域麻醉能在不影响病人意识状态、不要求全身骨骼肌松弛、不需要气道控制或机械通气的情况下提供外科麻醉条件。与硬膜外麻醉相比，脊髓麻醉操作费时少；麻醉起效更快；感觉运动阻滞更强；病人感觉更舒适。与脊髓麻醉相比，硬膜外麻醉发生穿刺后头痛的风险更低；麻醉平面可控性好；并能根据手术时间相应延长麻醉时间；由于起效较慢使低血压更易纠正；留置的硬膜外导管可用于急性术后疼痛治疗。

有些病人对区域麻醉实施过程中在后背进行穿刺和麻醉引起的麻痹感到害怕。有些外科医生对区域麻醉抱有偏见，至少部分是因为他们坚信区域麻醉会延迟手术开始或者无法满足手术需要。

References. Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; p. 168; Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000; pp. 1491-1492.


Sept 28 - Discuss the impact of smoking of preop pulmonary function

吸烟对术前肺功能的影响

Discussion points:

Cigarette smoking increases the irritability of the small airways, causes mucus hypersecretion, and decreases mucociliary transport. Carbon monoxide may also have negative inotropic effects. The net effect of this for patients scheduled to undergo thoracic surgery is an increase in the incidence of complications in the postoperative period.

There are many benefits of the preoperative cessation of cigarette smoking. Twelve to 18 hours after the cessation of cigarette smoking there are significant decreases in the carboxyhemoglobin level, a decrease in nicotine-induced tachycardia, and a normalization of the oxyhemoglobin dissociation curve. The oxyhemoglobin dissociation curve shifts to the right, making more oxygen available at the tissues. One to 2 weeks after the cessation of cigarette smoking there begins to be a decrease in the amount of mucus secretions in the airways. Four to 8 weeks after the cessation of cigarette smoking there is marked improvement in mucociliary transport, small airway reactivity, and secretions in the small airways. This is evidenced by the decrease in postoperative respiratory complications in patients who have quit smoking cigarettes for at least 8 weeks before surgery.

吸烟增加小气道的反应性，使粘液分泌过多，降低粘膜-纤毛转运。吸烟产生的一氧化碳具有支气管平滑肌收缩的负面效应。这些因素的净效应就是使择期行胸科手术病人术后呼吸道并发症发生率升高。

术前戒烟有许多益处。戒烟12~18小时能够明显降低碳氧血红蛋白水平，降低尼古丁诱发的心动过速发生率，使氧解离曲线趋于正常。氧解离曲线右移能使组织获得更多的氧。戒烟1~2周开始出现气道粘液分泌减少。戒烟4~8周能明显改善粘膜-纤毛转动，降低小气道的反应性，使小气道的分泌物减少。已经证实术前戒烟至少8周可减少术后呼吸系统并发症。

References: Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; p. 277. Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000. pp. 900, 957, 965, 1672-3.

Sept 29 - Discuss NIDDM & IDDM / acute & chronic complications

糖尿病及急慢性并发症

Discussion points:

The two major classifications of diabetes are insulin-dependent diabetes mellitus and non-insulin-dependent diabetes mellitus. Insulin-dependent diabetes mellitus, or type 1 diabetes, most often occurs in children and young adults. These patients are usually nonobese and are susceptible to ketoacidosis. Type 1 diabetes occurs as a result of immune-mediated destruction of insulin-producing cells in the pancreas. Non-insulin-dependent diabetes mellitus, or type 2 diabetes, usually occurs in obese patients after the age of 40 as a result of a resistance to the action of insulin. These patients are relatively resistant to ketoacidosis but may be prone to a hyperglycemic hyperosmolar nonketotic state. Over 90% of diabetics have type 2 diabetes mellitus.

Treatments for diabetes include a diabetic diet, oral hypoglycemic agents, and exogenous insulin.

Acute or chronic complications that can occur as a result of diabetes mellitus include hyperglycemia, hypoglycemia, ketoacidosis, autonomic neuropathy, coronary artery disease, cerebral vascular disease, peripheral vascular disease, nephropathy, retinopathy, sensory neuropathy, and stiff joint syndrome.

胰岛素依赖性糖尿病（IDDM）和非胰岛素依赖性糖尿病(NIDDM)是糖尿病的两种主要类型。胰岛素依赖性糖尿病，或称之为1型糖尿病，主要发生在儿童和年轻人。这些病人常不伴有肥胖，容易出现酮症酸中毒。1型糖尿病主要是由于免疫介导的胰腺中胰岛素生成细胞破坏引起的。非胰岛素依赖性糖尿病，或称之为2型糖尿病，主要发生在年龄超过40岁的的肥胖病人，伴有胰岛素抵抗。这些病人相对不易出现酮症酸中毒，但容易发生高血糖性高渗性非酮症状态。超过90%的糖尿病病人为2型糖尿病。

糖尿病的治疗包括糖尿病饮食，口服降糖药和外源性胰岛素治疗

糖尿病的急慢性并发症包括高血糖，低血糖，酮症酸中毒，自主神经系统病变，冠心病，脑血管病变，周围血管病，肾病，视网膜病变，感觉神经病变，关节僵硬综合征。

References. Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; p. 307; Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000; pp. 906-907.

Topic of the Day II(for CA-2’s and CA-3’s)

Sept 30 - Discuss diabetic ketoacidosis

糖尿病酮症酸中毒

Discussion points:

Patients with type 1 diabetes mellitus are predisposed to getting ketoacidosis. Ketoacidosis is a condition that occurs as a result of a severe insulin deficiency, usually in response to a precipitating stress. Patients with ketoacidosis may present with nausea and vomiting, lethargy, and abdominal pain. The diagnosis of ketoacidosis is made when hyperglycemia is accompanied by a severe metabolic acidosis leading to hyperventilation, an elevation in the anion gap, and the presence of ketones in the serum.
Causes of ketoacidosis include poor compliance with insulin therapy, infection, silent myocardial infarction, pregnancy, or some other physiologic stress. An underlying cause of ketoacidosis should be sought. Ketoacidosis is treated with intravascular fluid replacement; an insulin infusion to control the plasma glucose level; possible bicarbonate, potassium, and phosphate administration; and close monitoring of the urine output, serum glucose level, and electrolytes.

1型糖尿病病人更易于发生酮症酸中毒。酮症酸中毒由严重胰岛素缺乏引起，突发的应激是常见诱因。发生酮症酸中毒病人可伴有恶心呕吐，瞌睡和腹痛。当高血糖伴有由严重代谢性酸中毒引起的过度通气，阴离子间隙升高，血酮体升高时即可诊断为酮症酸中毒。

酮症酸中毒的原因包括胰岛素治疗依从性较差、感染、无症状性心肌梗死、妊娠和其他生理性应激状态。有酮症酸中毒时，应积极寻找其原因。酮症酸中毒的治疗包括静脉补液；胰岛素输注控制血糖水平；根据情况应用碳酸氢钠、钾和磷酸盐；密切监测尿量、血糖和电解质。

References. Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; p. 307; Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000; pp. 908-909, 1598, 2475-2476.

Oct 1 - Discuss diabetic autonomic neuropathy

糖尿病性自主神经病变

Discussion points:

Autonomic neuropathy, a dysfunction of the autonomic nervous system, occurs as a result of damage of small nerve fibers. This results in the loss of vagally controlled heart rate, a decrease in peripheral sympathetic nervous system tone resulting in orthostatic hypotension, decreases in peripheral blood flow, and diminished sweating. It is estimated that 50% of patients with diabetes and hypertension have autonomic neuropathy.

Signs and symptoms that a patient with diabetes has autonomic neuropathy include orthostatic hypotension, resting tachycardia, absent variation in heart rate with deep breathing, gastroparesis, peripheral neuropathy, asymptomatic hypoglycemia, and impotence. The diagnosis of autonomic neuropathy has clinical importance for the anesthesiologist managing the patient in the perioperative period. Patients with diabetic autonomic neuropathy are at an increased risk of delayed gastric emptying, peri operative hemodynamic instability, cardiac arrhythmias, silent myocardial infarction, impaired respiration, and cardiopulmonary arrest. In addition, these patients have a blunted response to atropine, making the early treatment of bradycardia essential in these patients.

自主神经病变是一种由细小神经纤维损伤导致的自主神经系统功能紊乱。自主神经病变会造成：心率迷走失支配；外周交感神经系统张力下降导致直立性低血压；外周血流减少和少汗。据估计50%合并高血压的糖尿病病人伴自主神经病变。

合并有自主神经病变的糖尿病病人的体征和症状包括直立性低血压、静息性心动过速、深呼吸时心率变异性丧失、胃轻瘫、周围神经病变、无症状性低血糖、阳萎。自主神经病变的诊断对糖尿病病人围术期麻醉管理很重要。糖尿病性自主神经病变的病人围术期发生胃排空延迟、血流动力学不稳定、心率失常、无症状的心肌梗死、呼吸功能受损和心肺骤停的风险增加。另外，由于对阿托品的治疗反应变得迟钝，心动过缓的早期治疗在这些病人中显得更加重要。

References. Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; pp. 307-308, 567; Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000; p. 911.


Oct 2 - Discuss perioperative anes. management goals of DM

糖尿病病人的围术期麻醉管理目标

Discussion points:

The goals of the anesthetic management of patients with diabetes include the maintenance of serum glucose, electrolyte, and intravascular fluid volume status. These goals can be achieved through adequate rehydration, often with a glucose-containing maintenance solution as well as an insulin infusion, the peri operative monitoring of serum glucose and electrolyte levels, and close monitoring of hemodynamics.
Considerations in the preoperative evaluation of the diabetic patient include the degree of glucose control; the patient's medical regimen for glucose control; evaluation of the serum electrolytes and other laboratory analysis; and any history or manifestations of cardiovascular disease, cerebral vascular disease, renal impairment, or autonomic or peripheral neuropathy. Indeed, diabetes itself may not be as predictive of peri operative morbidity as the end organ effects of the diabetes.

糖尿病病人的麻醉管理目标包括维持血糖，电解质和血管内容量的稳定。这些目标可以通过充分补充含糖液体维持液联合胰岛素输注、围术期监测血糖和电解质水平、密切监测血流动力学来实现。

糖尿病病人的术前评估要点包括血糖控制的水平、血糖控制的药物方案、血电解质和其他实验室检查、相关并发症的任何病史和临床表现（心血管病、脑血管疾病、肾脏损害、自主神经病变、周围神经病变）。事实上，糖尿病相关终末器官损害比糖尿病更能预测围术期发病率。

References. Stoelting RK, Miller RD: Basics of Anesthesia, 4th ed. Philadelphia, Churchill Livingstone, 2000; pp. 308-309; Miller RD: Anesthesia, 5th ed. Philadelphia, Churchill Livingstone, 2000; pp. 831, 905-906.

yinyilei

有关肌松药拮抗使用问题，园子里讨论过许多。从药物的起效快慢和持续时间搭配合理角度出发，以下药物合用比较合理：

新斯的明＋格隆溴胺

依氯酚铵＋阿托品

但依氯酚铵＋阿托品持续效果，比肌松药本身短，有可能使病人到 PACU （或病房）后再次出现肌松，已经很少用。

神经刺激使用，应该列为常规。手术当中，可以确保病人的肌松，术毕肌松中和前， TOF 中，至少有一个肌跳，才开始给肌松中和药物，中和完毕后，记录 TOF 4次肌跳，并有持续强直 （TOF=4/4, sustained tetany），这样医学和法律上都做到了位。

比较复杂的神经刺激器，可能要几百美元，但图中的简易型 (100型)，只要 100 多美元。我自己试验过，效果是一样的。神经刺激器，就象听诊器，是麻醉医生的必备工具。

yinyilei

http://www.dxy.cn/bbs/user/downl ... %8D%AF%E7%AD%89.mp3

qsj2008

辛苦了。这样能给予中英兼顾，是学习的好机会。