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1. General Anesthesia |
1． 全身麻醉 |
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Induction of General Anesthesia General anesthesia can be induced by giving drugs intravenously, by inhalation, or by a combination of both methods. |
全身麻醉的誘導 經靜脈、吸入或兩種方式聯(lián)合給藥都能誘導全身麻醉。 |
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A Rapid-Sequence Induction: Anesthesia is most commonly induced by the method of rapid-sequence induction, in which rapid administration of an ultra-short-acting barbiturate (e.g., thiopental) is followed by a depolarizing muscle relaxant (e.g., succinylcholine). This allows anesthesia to be induced within 30 seconds and the trachea to be intubated within 60-90 seconds. Oxygen is usually given by mask beforehand to allow maximum time for intubation while the patient is apneic. A non-depolarizing neuromuscular blocking drug (e.g., vecuronium, atracurium, or pancuronium) can be substituted for succinylcholine, but the onset of paralysis is delayed by about 60 seconds. |
A. 快速序貫誘導：誘導麻醉最常用的是快速序貫誘導方法，應用此法時先快速給予超短時作用的巴比妥（如硫賁妥鈉)，接著給去極化的肌肉松弛劑（如琥珀膽堿)。這樣能在30秒鐘內誘導麻醉，60－90秒鐘內行氣管插管。通常事先給予面罩吸氧，使患者在呼吸暫停的時間達最大限度，可用以插管。可以用非去極化的神經肌肉阻滯劑（如維可羅寧、卡肌寧或潘可羅寧)代替琥珀膽堿，但麻醉的出現(xiàn)將延遲60秒鐘。 |
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Rapid-sequence induction minimizes the time during which the trachea is unprotected. Consequently, this method is often used in emergency surgery in patients who have eaten recently. The disadvantage of giving depressant drugs rapidly is that hypotension may occur in patients with questionable cardiovascular status or marginal circulatory volume. |
快速序貫誘導能使氣管不受保護的時間縮短至最低限度，所以常用于剛剛進食患者的急診手術�？焖俳o予抑制劑的缺點是心血管功能有問題或循環(huán)容量在臨界水平的病人可發(fā)生低血壓。 |
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B Inhalation Induction: Inhalation of nitrous oxide plus a potent volatile anesthetic (e.g., halothane, enflurane, or isoflurane) can produce anesthesia within 3-5 minutes. After induction, a depolarizing or non-depolarizing neuromuscular blocking drug can be given intravenously to facilitate tracheal intubation. If there is some question about the difficulty of intubation, it can be attempted while the patient is breathing spontaneously, without giving a muscle relaxant. Although conditions for intubation may not be as good with this method, the patient will still be breathing if difficulties with intubation prolong the time before complete airway control is achieved. |
B. 吸入誘導：吸入一氧化氮加上強有力的揮發(fā)性麻醉劑（如氟烷、安氟醚或異氟醚)，能在3－5分鐘內誘導麻醉，誘導后可經靜脈給予去極化或非去極化的神經肌肉阻滯劑，以利于氣管插管。若認為氣管插管不一定有困難，可不用肌肉松弛劑而在病人有自主呼吸時試行插管。盡管這樣插管條件不如使用肌肉松弛劑好，但即使因插管困難推遲了達到完全氣道控制的時間，病人也仍能維持呼吸。 |
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The advantage of inhalation induction is that anesthetic drugs can be titrated according to the patient’s needs. This allows for administration of more precise doses and minimizes the risk of an accidental overdose with resultant cardiovascular depression. The disadvantages are a slower induction time and the lack of protection for the airway for a longer period of time.醫(yī)學.全在線www.med126.com |
吸入誘導的優(yōu)點在于可根據(jù)病人的需要滴入麻醉劑，這能使給藥劑量較為精確，并把意外過量導致心血管抑制的危險減少到最低限度。其缺點是誘導較慢以及氣道缺乏保護的時間較長。 |
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C Combined Intravenous-Inhalation Induction: Short-acting anesthetic drugs such as thiopental or diazepam are often administered intravenously before inhalation of a volatile anesthetic. This is done to minimize the discomfort of wearing the anesthetic mask and to facilitate inhalation of the anesthetic agent, which many people consider to have an offensive odor. This technique combines the advantages of both the intravenous and inhalation approaches. Anesthesia is induced rapidly, and anesthetic drug dosages can be titrated according to the patient’s requirements. |
C. 靜脈－吸入聯(lián)合誘導：在吸入揮發(fā)生麻醉劑之前常經靜脈給予短時麻醉劑如硫賁妥鈉和安定，這樣做能最大限度地減少帶麻醉面罩的不適感，并利于麻醉劑的吸入――許多人認為麻醉劑氣味難聞。這種方法結合了靜脈和吸入兩種方法的優(yōu)點，麻醉誘導迅速并可根據(jù)病人的需要滴入麻醉劑。 |
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Maintaining General Anesthesia The main objectives of general anesthesia are analgesia, unconsciousness, skeletal muscle relaxation, and control of sympathetic nervous system responses to noxious stimulation. Inhaled and intravenous anesthetics, narcotics, and muscle relaxants should be selected with specific pharmacologic goals in mind. |
全身麻醉的維持 全身麻醉的主要目的在于無痛、意識消失、和骨骼肌松弛以及控制交感神經對不良刺激的反應。應該注意根據(jù)特殊的藥理學目的來選擇吸入或靜脈麻醉劑、麻醉性鎮(zhèn)痛藥和肌肉松弛劑。 |
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Although paralysis by muscle relaxants simplified exposure of the operative site and decreases the need for volatile anesthetics, many signs of anesthesia are absent in the paralyzed patient. It is essential that the anesthesiologist continuously assess the depth of anesthesia. Failure to do so may result in the patient being awake but paralyzed during the procedure. |
盡管肌肉松弛劑所導致的麻痹使手術野易于暴露并減少揮發(fā)性麻醉劑的需要量，但麻痹病人缺乏許多麻醉征象。麻醉師必須持續(xù)不斷地評估麻醉深度。如果做不到這一點就會導致在麻醉過程中病人清醒而肌肉麻痹的后果。 |
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2. Regional Anesthesia |
2． 區(qū)域了阻滯 |
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A regional anesthetic is used when it is desirable that the patient remain conscious during the operation. Patients often have misconceptions about regional anesthesia that require detailed explanation of the safety of this technique. One disadvantage of regional anesthesia is the occasional failure to produce adequate anesthesia; another is hypotension due to sympathetic blockade. Regional anesthesia is used most often for surgery of the lower abdomen or lower extremities, since the effect of sympathetic blockade of these areas is minimal. |
若需要病人手術期間保持清醒，可用區(qū)域麻醉阻滯。病人對區(qū)域麻醉常有誤解，需要詳細解釋這一方法的安全性。區(qū)域麻醉的缺點之一是偶爾不能獲得滿意的麻醉，另外一個缺點是交感阻滯引起的低血壓。區(qū)域麻醉最常用于下腹部和下肢的手術，因為這些部位交感阻滯影響極小。 |
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Spinal & Epidural Blocks Spinal anesthesia is achieved by injecting a local anesthetic into the lumbar intrathecal space. This blocks the spinal nerve roots and dorsal root ganglia and probably also blocks the periphery of the spinal cord. Epidural anesthesia is accomplished by injecting a local anesthetic into the extradural (epidural) space. The epidural space is usually identified via the lumbar approach. The gastrointestinal tract is usually contracted with spinal and epidural anesthesia, facilitating exposure of the surgical site. |
脊髓和硬膜外阻滯 將局麻藥注射到腰部鞘內間隙可獲得脊髓麻醉，阻滯了脊神經根和脊根神經節(jié)，可能也阻滯脊髓的外周部分。將局麻藥注入硬膜外腔則產生硬膜外麻醉。一般通過腰部通路進入硬膜外腔。脊髓和硬膜外麻醉時胃腸道呈收縮狀態(tài)有利于手術野暴露。 |
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There are several complications of spinal anesthesia. Headache is the most common and is seen most frequently in young patients. The incidence is only 1% when a 25-gauge needle is used. For severe headache, a “blood-patch” epidural injection should be performed. This involves injecting 5-10 ml of the patient’s blood into the epidural space at the site of the previous lumbar puncture. Pain relief is usually prompt, and headache usually does not recur. This technique is thought to plug the leak of cerebrospinal fluid, restoring pressure in the subarachnoid space to normal. |
脊髓麻醉有幾種并發(fā)癥，其中最常見的是頭痛，且最多見于年輕病人。如果用25號針頭，發(fā)生率僅為1%。對于嚴重的頭痛應施行“血液綴片”硬膜外腔注入術，就是將5－10ml病人的血液經原腰區(qū)穿刺處注入硬膜外腔。通常，疼痛可即刻緩解，一般，頭痛亦不再復發(fā)。據(jù)認為這一技術堵塞了腦脊液的外漏，使蛛網膜下腔的壓力恢復正常。 |
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Because spinal anesthesia blocks innervation of the bladder, administration large amounts of intravenous fluids may cause bladder distention, and a urethral catheter may be carried. This usually occurs with minor operations such as inguinal hernia repairs and can be avoided by keeping fluids to a minimum. Nausea and vomiting may occur when a spinal anesthetic is begun, especially if hypotension is present. If nausea and vomiting persist despite successful treatment of hypotension, diazepam or droperidol may be effective. Peripheral nerve damage is rare, occurring in one out of 10,000 cases. |
因脊髓麻醉阻滯了膀胱的神經支配，大量靜脈輸液會引起膀胱膨脹，因此可能需要插導尿管。這種情況通常發(fā)生于很小的手術如腹股溝斜疝修補術，維持液體至最低量即可避免。在脊髓麻醉開始特別是有低血壓時，會發(fā)生惡心嘔吐。如果低血壓治療已經成功而惡心嘔吐仍持續(xù)存在，用安定或氟哌啶可能奏效。外周神經損傷是很罕見的，發(fā)生于1/10,000的病例。 |
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Complications from epidural anesthesia are the same as those for spinal anesthesia, with the exception of headache. |
除頭痛外，硬膜外麻醉的并發(fā)癥與脊髓麻醉相同。 |
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3. Nerve Blocks |
3． 神經阻滯 |
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Nerve blocks are most appropriate for surgery of the upper extremities. Intercostal nerve blocks are useful for postoperative pain relief. Overall, nerve blocks play a minor role in anesthesia because of the discomfort they cause the patient and the time they require. |
神經阻滯最適用于上肢，肋間神經阻滯有助于緩解術后疼痛�？偟恼f來，由于神經阻滯引起病人不適及所需時間長，因而在麻醉中起的作用很小。 |
