【正文】 n but rather to hypoperfusion of the respiratory centers in the brainstem 呼吸暫停與腦干呼吸中樞血流灌注不足有關(guān)，與呼吸肌功能無(wú)關(guān) ★ Gastrointestinal manifestations(胃腸道影響） Spinal block sympathetic block vagal tone a contracted gut with active peristasis （內(nèi)臟收縮，蠕動(dòng) ） ★ Urinary tract manifestations（泌尿系統(tǒng)影響） Renal blood flow is maintained through autoregulation, and there is little clinical effect on renal function from spinal block. 腎功能影響小 三、蛛網(wǎng)膜下腔阻滯的臨床應(yīng)用 (The clinical applications of subarachnoid block) (一 )適應(yīng)證 (indications)： ?下腹部手術(shù)，如：闌尾切除術(shù)、疝修補(bǔ)術(shù) ?肛門(mén)及會(huì)陰部手術(shù)，如：痔切除術(shù) ?盆腔手術(shù)，如：子宮切除、膀胱手術(shù) ?下肢手術(shù)，如：截肢手術(shù) ( 二 ) 禁忌證 (contraindications) ?Absolute contraindications ? Infection at the site of injection ? Patient refusal ? Coagulopathy or other bleeding diathesis ? Severe hypovolemia ? Increased intracranial pressure ? Severe aortic stenosis ? Severe mitral stenosis ( 二 ) 禁忌證 (contraindications) ?Relative contraindications ? Sepsis ? Uncooperative patient ? Preexisting neurological deficits ? Demyelinating lesions ? Stenotic valvular heart lesions ? Severe spinal deformity ( 二 ) 禁忌證 (contraindications) ?Controversial contraindications ? Prior back surgery at the site of injection ? Inability to municate with patient ? Complicated surgery ? Major blood loss ? Maneuvers that promise respiration ? Prolonged operation （三）麻醉前準(zhǔn)備 preanesthetic preparation ? Equipment Respirator Monitor Oxygen ? drugs Local anesthetic vasoactive agent (四 )常用局麻藥： (Commonly used spinal anesthetic agents) ▲ Procaine： procaine 150mg+ or + 5% +%. ▲ Dicaine: 最常用重比重液（ 111溶液） : 1%Dicaine 1ml+35% Ephedrine 1ml+10% 1ml： 即 : %Dicaine（ 1015mg) ▲ Bupivacaine： 常用重比重液： % Bupivacaine 2ml+10%GS 1ml 常用 812mg (五 )蛛網(wǎng)膜下腔穿刺術(shù) : ( Performing a lumbar puncture) ● 體位 (Patient position): ★ Sitting position: ★ Lateral decubitus ★ Prone position: ● 定位 (Identification of lumbar interspaces): A line drawn between both iliac crests usually crosses either the body of L4 or the L34 interspace. ● 穿刺間隙 (Lumbar interspace of peration): L34. Performing a lumbar puncture below L1 in adults or L3 in children avoids needle trauma to the cord. ● 穿刺方法 (approachs): ? 直入法 midline approach The midline approach is the technique of first choice because it requires anatomic projection in only two planes and provides a relatively avascular plane. ? 側(cè)入法 paramidline approach When difficulty in needle insertion is encountered with the midline approach, one option is to use the paramedian route, which does not require the same level of patient cooperation and reversal of lumbar lordosis for success. (六 )阻滯平面的調(diào)節(jié) (regulating the level of blockade) 阻滯平面指 皮膚感覺(jué)消失的界限 The level of sensory blockade can be assessed With pinprick. The motor blockade is two segments lower than the sensory blockade. 麻醉藥注入蛛網(wǎng)膜下隙后，要在短時(shí)間內(nèi)主動(dòng)調(diào)節(jié) 和控制麻醉平面，達(dá)手術(shù)所需范圍，但應(yīng)避免平面 過(guò)高 。 ★ 麻醉平面的影響因素 factors postulates to be related to spinal anesthetic block height ?穿刺間隙 ?藥物種類(lèi)、濃度、劑量及比重 ?注藥速度、針口方向 ?病人特征 Patient characteristics Factors Postulated to be Related to Spinal Anesthetic Block Height ?Characteristics of anesthetic solution ?Density ?Amount (mass) ?Concentration ?Temperature ?Volume ?Vasoconstrictors Factors Postulated to be Related to Spinal Anesthetic Block Height ? Technique of injection ?Site of injection ?