左心衰尽和右心衰尽的临床表现、显现机制及区别
<h2 style="color: black; text-align: left; margin-bottom: 10px;"><span style="color: black;">1、</span>左心衰<span style="color: black;">导致</span>肺循环淤血，肺水肿。</h2>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">肺循环淤血<span style="color: black;">重点</span>见于左心衰<span style="color: black;">病人</span>。当肺毛细血管楔压<span style="color: black;">上升</span>，<span style="color: black;">首要</span><span style="color: black;">显现</span>肺循环淤血，严重时可<span style="color: black;">显现</span>肺水肿。肺淤血、肺水肿的<span style="color: black;">一起</span>表现<span style="color: black;">便是</span><span style="color: black;">呼气</span>困难，为<span style="color: black;">病人</span>气短及<span style="color: black;">呼气</span>费力的主观感觉，<span style="color: black;">拥有</span><span style="color: black;">必定</span>的限制体力活动的<span style="color: black;">守护</span><span style="color: black;">道理</span>，<span style="color: black;">亦</span>是判断肺淤血程度的指标。</p>
<h2 style="color: black; text-align: left; margin-bottom: 10px;"><span style="color: black;">呼气</span>困难<span style="color: black;">出现</span>的基本机制:</h2>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">①肺淤血、肺水肿<span style="color: black;">引起</span>肺顺应性降低，要吸入<span style="color: black;">一样</span>量的空气，<span style="color: black;">必须</span><span style="color: black;">增多</span><span style="color: black;">呼气</span>肌做功，消耗<span style="color: black;">更加多</span>的能量，故<span style="color: black;">病人</span>感到<span style="color: black;">呼气</span>费力</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">②支气管黏膜充血、肿胀及气道内分泌物<span style="color: black;">引起</span>气道阻力增大</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">③肺毛细血管压<span style="color: black;">升高</span>和间质水肿使肺间质压力<span style="color: black;">升高</span>，刺激肺毛细血管旁J受体，<span style="color: black;">导致</span>反射性浅快<span style="color: black;">呼气</span>。</p>
<h2 style="color: black; text-align: left; margin-bottom: 10px;"><span style="color: black;">呼气</span>困难的表现形式</h2>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">（1）劳力性<span style="color: black;">呼气</span>困难:轻度左心衰<span style="color: black;">病人</span>仅在体力活动时出现<span style="color: black;">呼气</span>困难，<span style="color: black;">休憩</span>后消失，<span style="color: black;">叫作</span>为劳力性<span style="color: black;">呼气</span>困难，为左心<span style="color: black;">衰尽</span>最早的表现。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">其机制是:①体力活动时四肢血流量<span style="color: black;">增多</span>，回心血量<span style="color: black;">增加</span>，肺淤血加重。②体力活动时心率加快，舒张期缩短，左心室充盈减少，肺循环淤血加重。③体力活动<span style="color: black;">机会</span>体需氧量<span style="color: black;">增多</span>，但<span style="color: black;">衰尽</span>的左心室<span style="color: black;">不可</span>相应地<span style="color: black;">加强</span>心排血量，<span style="color: black;">因此呢</span>机体缺氧进一步加重，刺激<span style="color: black;">呼气</span>中枢，使<span style="color: black;">呼气</span>加深加快，<span style="color: black;">显现</span><span style="color: black;">呼气</span>困难。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">（2）夜间阵发性<span style="color: black;">呼气</span>困难:夜间阵发性<span style="color: black;">呼气</span>困难<span style="color: black;">也</span>是左心<span style="color: black;">衰尽</span><span style="color: black;">初期</span>的典型表现。<span style="color: black;">病人</span>夜间入睡后因突感气闷、气急而惊醒，被迫坐起，可伴有咳嗽或<span style="color: black;">泡泡</span>样痰，<span style="color: black;">爆发</span>较轻者在坐起后有所缓解，经过一段时间后<span style="color: black;">自动</span>消失。严重者可<span style="color: black;">连续</span><span style="color: black;">爆发</span>，咳粉红色<span style="color: black;">泡泡</span>样痰，<span style="color: black;">乃至</span>发展为急性肺水肿。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;"><span style="color: black;">出现</span>机制:①<span style="color: black;">病人</span>入睡后由端坐位改为平卧位，下半身静脉回流<span style="color: black;">增加</span>，水肿液吸收入血液循环<span style="color: black;">亦</span><span style="color: black;">增加</span>，加重肺淤血。②入睡后迷走神经紧张性<span style="color: black;">升高</span>，使小支气管收缩，气道阻力增大。③熟睡后中枢对传入刺激的<span style="color: black;">敏锐</span>性降低，<span style="color: black;">仅有</span>当肺淤血程度较为严重，动脉血氧分压降低到<span style="color: black;">必定</span>程度时，方能刺激<span style="color: black;">呼气</span>中枢，使<span style="color: black;">病人</span>感到<span style="color: black;">呼气</span>困难而惊醒。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">（3）端坐<span style="color: black;">呼气</span>:<span style="color: black;">病人</span>在静息时<span style="color: black;">已然</span><span style="color: black;">显现</span><span style="color: black;">呼气</span>困难，平卧时加重，故需被迫采取端坐卧位或半卧位以减轻<span style="color: black;">呼气</span>困难的程度，<span style="color: black;">叫作</span>为端坐<span style="color: black;">呼气</span>。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">其机制是:①端坐位时下肢血液回流减少，肺淤血减轻；②膈肌下移，胸腔容积增大，肺活量<span style="color: black;">增多</span>，通气改善。③端坐位<span style="color: black;">能够</span>减少下肢水肿液的吸收，使血容量降低，减轻肺淤血。端坐<span style="color: black;">呼气</span>是左心衰<span style="color: black;">导致</span>严重肺淤血的表现。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">（4）急性肺水肿:为急性左心<span style="color: black;">衰尽</span>的<span style="color: black;">重点</span>临床表现。<span style="color: black;">因为</span>突发左心室排血减少，<span style="color: black;">导致</span>肺静脉和肺毛细血管压力急剧<span style="color: black;">上升</span>，毛细血管壁通透性增大，<span style="color: black;">血液</span>渗出到肺间质与肺泡而<span style="color: black;">导致</span>急性肺水肿。此时，<span style="color: black;">病人</span>可<span style="color: black;">显现</span>发绀、气促、端坐<span style="color: black;">呼气</span>、咳嗽、咳粉红色<span style="color: black;">泡泡</span>样痰等症状和体征。</p>
<div style="color: black; text-align: left; margin-bottom: 10px;"><img src="https://pic4.zhimg.com/80/v2-d287f6f0030dfedf239468ebd621a427_720w.webp" style="width: 50%; margin-bottom: 20px;"></div>
<h2 style="color: black; text-align: left; margin-bottom: 10px;"><span style="color: black;">2、</span>右心衰<span style="color: black;">导致</span>体循环淤血。</h2>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">体循环淤血见于右心衰及全心<span style="color: black;">衰尽</span>，主要表现为体循环静脉系统的过度充盈、静脉压<span style="color: black;">上升</span>、内脏充血和水肿等。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">1、静脉淤血和静脉压<span style="color: black;">上升</span>。右心<span style="color: black;">衰尽</span>时因水钠潴留及右室舒张末期压力<span style="color: black;">上升</span>，使上下腔静脉回流受阻，静脉<span style="color: black;">反常</span>充盈，表现为下肢和内脏的淤血。右心淤血<span style="color: black;">显著</span>时<span style="color: black;">显现</span>颈静脉充盈或怒张。按压肝脏后颈静脉<span style="color: black;">反常</span>充盈，<span style="color: black;">叫作</span>为肝颈静脉反流征阳性。静脉淤血和交感神经兴奋<span style="color: black;">导致</span>的容量血管收缩，可使静脉压<span style="color: black;">上升</span>。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">2、肝肿大及肝功能损害。<span style="color: black;">因为</span>下腔静脉回流受阻，肝静脉压<span style="color: black;">上升</span>，肝小叶中央区淤血，肝窦扩张、<span style="color: black;">流血</span>及<span style="color: black;">周边</span>水肿，<span style="color: black;">引起</span>肝脏肿大，局部有压痛。<span style="color: black;">长时间</span>右心<span style="color: black;">衰尽</span>，还可<span style="color: black;">导致</span>心源性肝硬化。因肝细胞变性、坏死，<span style="color: black;">病人</span>可<span style="color: black;">显现</span>转氨酶水平<span style="color: black;">升高</span>及黄疸。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">3、胃肠功能改变。慢性心功能不全时，<span style="color: black;">因为</span>胃肠道淤血及动脉血液灌流不足，可<span style="color: black;">显现</span>消化系统功能<span style="color: black;">阻碍</span>，表现为消化不良、食欲缺乏、恶心、呕吐、腹泻等。</p>
<p style="font-size: 16px; color: black; line-height: 40px; text-align: left; margin-bottom: 15px;">4、水肿。水肿是右心<span style="color: black;">衰尽</span>以及全心<span style="color: black;">衰尽</span>的<span style="color: black;">重点</span>临床表现之一，<span style="color: black;">叫作</span>为心性水肿。受重力的影响，心性水肿在体位低的下肢表现最为<span style="color: black;">显著</span>，严重者还可伴发腹水及胸水等。毛细血管血压<span style="color: black;">升高</span>是心性水肿的始发<span style="color: black;">原因</span>，而肾血流量减少可引起肾小球滤过率降低和醛固酮<span style="color: black;">增多</span>，<span style="color: black;">导致</span>钠、水潴留，促进水肿的发展。<span style="color: black;">另外</span>，<span style="color: black;">因为</span>胃肠道淤血<span style="color: black;">导致</span><span style="color: black;">食品</span>消化吸收<span style="color: black;">阻碍</span>、肝淤血<span style="color: black;">导致</span>的肝功能<span style="color: black;">损害</span>可<span style="color: black;">引起</span>低蛋白血症，又进一步加重心性水肿。</p>
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