如何正确估算失血量,看完就会!

2018-02-14 佚名 医学之声

失血量的估计可根据血容量减少导致周围循环的改变而作出判断。


失血量的估计可根据血容量减少导致周围循环的改变而作出判断。

以呕血、便血的量作为估计失血量的资料,往往不太精确。因为一方面,呕血与便血常分别混有胃内容物与粪便;另一方面,部分血液尚贮留在胃肠道内,仍未排出体外。因此,失血量的估计可根据血容量减少导致周围循环的改变作出判断。

一般情况

一般每日出血量在5ml以上,大便颜色不变但隐血试验就可为阳性,出血量在50~100ml以上则会出现黑便。如病人的失血量在400ml以下,血容量轻度减少,可由组织液及脾贮血所补偿,循环血量在1h内即得改善,故其常无自觉症状。

当出现头晕、心慌、冷汗、乏力、口干等症状时,表示急性失血在400ml以上;如果有晕厥、四肢冰凉、尿少、烦躁不安时,表示出血量大,失血至少在1200ml以上;若出血仍然继续,除晕厥外,尚有气短、无尿,此时急性失血已达2000ml以上。

脉搏

脉搏的改变是失血程度的重要指标。急性消化道出血时血容量锐减,最初的机体代偿功能是心率加快,小血管反射性痉挛,使肝、脾、皮肤血窦内的储血进入循环,增加回心血量,调整体内有效循环量,以保证心、肾、脑等重要器官的供血。

一旦病人失血量过大,机体代偿功能不足以维持有效血容量时,其就可能进入休克状态。所以,当大量出血时,脉搏快而弱(或脉细弱),脉搏每分钟增至100~120次以上,失血估计为800~1600ml;脉搏细微,甚至扪不清时,失血已达1600ml以上。

有些病人出血后,在平卧时脉搏、血压都可接近正常,但让病人坐或半卧位时,脉搏会马上增快,出现头晕、冷汗,表示失血量大。如果经改变体位无上述变化,测中心静脉压又正常,则可以排除有过大出血。

血压

血压的变化同脉搏一样,是估计失血量的可靠指标。当急性失血800ml以上时(占总血量的20%),收缩压可正常或稍升高,脉压缩小。尽管此时血压尚正常,但病人已进入休克早期,应密切观察血压的动态改变。

急性失血800~1600ml时(占总血量的20%~40%),收缩压可降至9.33~10.67kPa(70~80mmHg),脉压小。急性失血1600ml以上时(占总血量的40%),收缩压可降至6.67~9.33kPa(50~70mmHg)。

更严重的出血,血压可降至零。有人主张用休克指数来估计失血量,休克指数=脉率/收缩压,正常值为0.58,表示血容量正常;指数=1,大约失血800~1200ml(占总血量20%~30%);指数>1,失血1200~2000ml(占总血量30%~50%)。

有时,一些有严重消化道出血的病人,胃肠道内的血液尚未排出体外,仅表现为休克,此时应注意排除心源性休克(急性心肌梗死)、感染性或过敏性休克,以及非消化道的内出血(宫外孕或主动脉瘤破裂)。若发现肠鸣音活跃,肛检有血便,则提示为消化道出血。

血象

血红蛋白测定、红细胞计数、血细胞压积可以帮助估计失血的程度。但在急性失血的初期,由于血浓缩及血液重新分布等代偿机制,上述数值可以暂时无变化。一般需组织液渗入血管内补充血容量,即3~4h后才会出现血红蛋白下降,平均在出血后32h,血红蛋白可被稀释到最大程度。

如果病人出血前无贫血,血红蛋白在短时间内下降至7g以下,表示出血量大,在1200ml以上。大出血后2~5h,白细胞计数可增高,但通常不超过15×109/L,然而在肝硬化、脾功能亢进时,白细胞计数可以不增加。

尿素氮

上消化道大出血后数小时,血尿素氮增高,1~2天达高峰,3~4天内降至正常。如再次出血,尿素氮可再次增高。尿素氮增高是由于大量血液进入小肠,含氮产物被吸收。而血容量减少导致肾血流量及肾小球滤过率下降,则不仅尿素氮增高,肌酐亦可同时增高。如果肌酐在133μmol/L(1.5mg%)以下,而尿素氮>14.28mmol/L(40mg%),则提示上消化道出血在1000ml以上。

骨折失血

一般情况下,肱骨骨折出血量约为100~800ml,尺骨骨折出血量约为50~400ml。

版权声明:
本网站所有内容来源注明为“梅斯医学”或“MedSci原创”的文字、图片和音视频资料,版权均属于梅斯医学所有。非经授权,任何媒体、网站或个人不得转载,授权转载时须注明来源为“梅斯医学”。其它来源的文章系转载文章,或“梅斯号”自媒体发布的文章,仅系出于传递更多信息之目的,本站仅负责审核内容合规,其内容不代表本站立场,本站不负责内容的准确性和版权。如果存在侵权、或不希望被转载的媒体或个人可与我们联系,我们将立即进行删除处理。
在此留言
评论区 (5)
#插入话题
  1. [GetPortalCommentsPageByObjectIdResponse(id=1522662, encodeId=8eb3152266278, content=<a href='/topic/show?id=4c364430828' target=_blank style='color:#2F92EE;'>#失血#</a>, beContent=null, objectType=article, channel=null, level=null, likeNumber=42, replyNumber=0, topicName=null, topicId=null, topicList=[TopicDto(id=44308, encryptionId=4c364430828, topicName=失血)], attachment=null, authenticateStatus=null, createdAvatar=null, createdBy=d6c011466504, createdName=daviiliu, createdTime=Fri Feb 16 12:34:00 CST 2018, time=2018-02-16, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288048, encodeId=1d21288048e7, content=学习了, beContent=null, objectType=article, channel=null, level=null, likeNumber=49, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=, createdBy=a8f22260741, createdName=121832a9m88暂无昵称, createdTime=Thu Feb 15 04:58:19 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288026, encodeId=6221288026cd, content=学习了, beContent=null, objectType=article, channel=null, level=null, likeNumber=62, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=https://cdnapi.center.medsci.cn/medsci/head/2018/01/15/8213228fe923915543544ad3da7e1c64.jpg, createdBy=6bd82014262, createdName=秀红, createdTime=Thu Feb 15 01:09:11 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288019, encodeId=13022880195f, content=学习了.有用, beContent=null, objectType=article, channel=null, level=null, likeNumber=59, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=, createdBy=73441710184, createdName=明崖, createdTime=Thu Feb 15 00:33:48 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=287977, encodeId=fb3928e977c9, content=以呕血.便血的量作为估计失血量的资料.往往不太精确.因为一方面.呕血与便血常分别混有胃内容物与粪便,另一方面.部分血液尚贮留在胃肠道内.仍未排出体外.因此.失血量的估计可根据血容量减少导致周围循环的改变作出判断., beContent=null, objectType=article, channel=null, level=null, likeNumber=74, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=https://wx.qlogo.cn/mmopen/NUyjXTCJjo7cJ6ejWUr2nIia8qOvAKNdLHr32Df6G8iaoaOx6pHaoiacwp26DaslxZHCGbibZhhCGven4rvmWP60GahtzgFjgCjR/0, createdBy=6b111703011, createdName=有备才能无患, createdTime=Wed Feb 14 22:27:53 CST 2018, time=2018-02-14, status=1, ipAttribution=)]
    2018-02-16 daviiliu
  2. [GetPortalCommentsPageByObjectIdResponse(id=1522662, encodeId=8eb3152266278, content=<a href='/topic/show?id=4c364430828' target=_blank style='color:#2F92EE;'>#失血#</a>, beContent=null, objectType=article, channel=null, level=null, likeNumber=42, replyNumber=0, topicName=null, topicId=null, topicList=[TopicDto(id=44308, encryptionId=4c364430828, topicName=失血)], attachment=null, authenticateStatus=null, createdAvatar=null, createdBy=d6c011466504, createdName=daviiliu, createdTime=Fri Feb 16 12:34:00 CST 2018, time=2018-02-16, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288048, encodeId=1d21288048e7, content=学习了, beContent=null, objectType=article, channel=null, level=null, likeNumber=49, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=, createdBy=a8f22260741, createdName=121832a9m88暂无昵称, createdTime=Thu Feb 15 04:58:19 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288026, encodeId=6221288026cd, content=学习了, beContent=null, objectType=article, channel=null, level=null, likeNumber=62, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=https://cdnapi.center.medsci.cn/medsci/head/2018/01/15/8213228fe923915543544ad3da7e1c64.jpg, createdBy=6bd82014262, createdName=秀红, createdTime=Thu Feb 15 01:09:11 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288019, encodeId=13022880195f, content=学习了.有用, beContent=null, objectType=article, channel=null, level=null, likeNumber=59, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=, createdBy=73441710184, createdName=明崖, createdTime=Thu Feb 15 00:33:48 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=287977, encodeId=fb3928e977c9, content=以呕血.便血的量作为估计失血量的资料.往往不太精确.因为一方面.呕血与便血常分别混有胃内容物与粪便,另一方面.部分血液尚贮留在胃肠道内.仍未排出体外.因此.失血量的估计可根据血容量减少导致周围循环的改变作出判断., beContent=null, objectType=article, channel=null, level=null, likeNumber=74, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=https://wx.qlogo.cn/mmopen/NUyjXTCJjo7cJ6ejWUr2nIia8qOvAKNdLHr32Df6G8iaoaOx6pHaoiacwp26DaslxZHCGbibZhhCGven4rvmWP60GahtzgFjgCjR/0, createdBy=6b111703011, createdName=有备才能无患, createdTime=Wed Feb 14 22:27:53 CST 2018, time=2018-02-14, status=1, ipAttribution=)]
    2018-02-15 121832a9m88暂无昵称

    学习了

    0

  3. [GetPortalCommentsPageByObjectIdResponse(id=1522662, encodeId=8eb3152266278, content=<a href='/topic/show?id=4c364430828' target=_blank style='color:#2F92EE;'>#失血#</a>, beContent=null, objectType=article, channel=null, level=null, likeNumber=42, replyNumber=0, topicName=null, topicId=null, topicList=[TopicDto(id=44308, encryptionId=4c364430828, topicName=失血)], attachment=null, authenticateStatus=null, createdAvatar=null, createdBy=d6c011466504, createdName=daviiliu, createdTime=Fri Feb 16 12:34:00 CST 2018, time=2018-02-16, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288048, encodeId=1d21288048e7, content=学习了, beContent=null, objectType=article, channel=null, level=null, likeNumber=49, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=, createdBy=a8f22260741, createdName=121832a9m88暂无昵称, createdTime=Thu Feb 15 04:58:19 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288026, encodeId=6221288026cd, content=学习了, beContent=null, objectType=article, channel=null, level=null, likeNumber=62, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=https://cdnapi.center.medsci.cn/medsci/head/2018/01/15/8213228fe923915543544ad3da7e1c64.jpg, createdBy=6bd82014262, createdName=秀红, createdTime=Thu Feb 15 01:09:11 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288019, encodeId=13022880195f, content=学习了.有用, beContent=null, objectType=article, channel=null, level=null, likeNumber=59, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=, createdBy=73441710184, createdName=明崖, createdTime=Thu Feb 15 00:33:48 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=287977, encodeId=fb3928e977c9, content=以呕血.便血的量作为估计失血量的资料.往往不太精确.因为一方面.呕血与便血常分别混有胃内容物与粪便,另一方面.部分血液尚贮留在胃肠道内.仍未排出体外.因此.失血量的估计可根据血容量减少导致周围循环的改变作出判断., beContent=null, objectType=article, channel=null, level=null, likeNumber=74, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=https://wx.qlogo.cn/mmopen/NUyjXTCJjo7cJ6ejWUr2nIia8qOvAKNdLHr32Df6G8iaoaOx6pHaoiacwp26DaslxZHCGbibZhhCGven4rvmWP60GahtzgFjgCjR/0, createdBy=6b111703011, createdName=有备才能无患, createdTime=Wed Feb 14 22:27:53 CST 2018, time=2018-02-14, status=1, ipAttribution=)]
    2018-02-15 秀红

    学习了

    0

  4. [GetPortalCommentsPageByObjectIdResponse(id=1522662, encodeId=8eb3152266278, content=<a href='/topic/show?id=4c364430828' target=_blank style='color:#2F92EE;'>#失血#</a>, beContent=null, objectType=article, channel=null, level=null, likeNumber=42, replyNumber=0, topicName=null, topicId=null, topicList=[TopicDto(id=44308, encryptionId=4c364430828, topicName=失血)], attachment=null, authenticateStatus=null, createdAvatar=null, createdBy=d6c011466504, createdName=daviiliu, createdTime=Fri Feb 16 12:34:00 CST 2018, time=2018-02-16, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288048, encodeId=1d21288048e7, content=学习了, beContent=null, objectType=article, channel=null, level=null, likeNumber=49, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=, createdBy=a8f22260741, createdName=121832a9m88暂无昵称, createdTime=Thu Feb 15 04:58:19 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288026, encodeId=6221288026cd, content=学习了, beContent=null, objectType=article, channel=null, level=null, likeNumber=62, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=https://cdnapi.center.medsci.cn/medsci/head/2018/01/15/8213228fe923915543544ad3da7e1c64.jpg, createdBy=6bd82014262, createdName=秀红, createdTime=Thu Feb 15 01:09:11 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288019, encodeId=13022880195f, content=学习了.有用, beContent=null, objectType=article, channel=null, level=null, likeNumber=59, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=, createdBy=73441710184, createdName=明崖, createdTime=Thu Feb 15 00:33:48 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=287977, encodeId=fb3928e977c9, content=以呕血.便血的量作为估计失血量的资料.往往不太精确.因为一方面.呕血与便血常分别混有胃内容物与粪便,另一方面.部分血液尚贮留在胃肠道内.仍未排出体外.因此.失血量的估计可根据血容量减少导致周围循环的改变作出判断., beContent=null, objectType=article, channel=null, level=null, likeNumber=74, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=https://wx.qlogo.cn/mmopen/NUyjXTCJjo7cJ6ejWUr2nIia8qOvAKNdLHr32Df6G8iaoaOx6pHaoiacwp26DaslxZHCGbibZhhCGven4rvmWP60GahtzgFjgCjR/0, createdBy=6b111703011, createdName=有备才能无患, createdTime=Wed Feb 14 22:27:53 CST 2018, time=2018-02-14, status=1, ipAttribution=)]
    2018-02-15 明崖

    学习了.有用

    0

  5. [GetPortalCommentsPageByObjectIdResponse(id=1522662, encodeId=8eb3152266278, content=<a href='/topic/show?id=4c364430828' target=_blank style='color:#2F92EE;'>#失血#</a>, beContent=null, objectType=article, channel=null, level=null, likeNumber=42, replyNumber=0, topicName=null, topicId=null, topicList=[TopicDto(id=44308, encryptionId=4c364430828, topicName=失血)], attachment=null, authenticateStatus=null, createdAvatar=null, createdBy=d6c011466504, createdName=daviiliu, createdTime=Fri Feb 16 12:34:00 CST 2018, time=2018-02-16, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288048, encodeId=1d21288048e7, content=学习了, beContent=null, objectType=article, channel=null, level=null, likeNumber=49, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=, createdBy=a8f22260741, createdName=121832a9m88暂无昵称, createdTime=Thu Feb 15 04:58:19 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288026, encodeId=6221288026cd, content=学习了, beContent=null, objectType=article, channel=null, level=null, likeNumber=62, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=https://cdnapi.center.medsci.cn/medsci/head/2018/01/15/8213228fe923915543544ad3da7e1c64.jpg, createdBy=6bd82014262, createdName=秀红, createdTime=Thu Feb 15 01:09:11 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=288019, encodeId=13022880195f, content=学习了.有用, beContent=null, objectType=article, channel=null, level=null, likeNumber=59, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=, createdBy=73441710184, createdName=明崖, createdTime=Thu Feb 15 00:33:48 CST 2018, time=2018-02-15, status=1, ipAttribution=), GetPortalCommentsPageByObjectIdResponse(id=287977, encodeId=fb3928e977c9, content=以呕血.便血的量作为估计失血量的资料.往往不太精确.因为一方面.呕血与便血常分别混有胃内容物与粪便,另一方面.部分血液尚贮留在胃肠道内.仍未排出体外.因此.失血量的估计可根据血容量减少导致周围循环的改变作出判断., beContent=null, objectType=article, channel=null, level=null, likeNumber=74, replyNumber=0, topicName=null, topicId=null, topicList=[], attachment=null, authenticateStatus=null, createdAvatar=https://wx.qlogo.cn/mmopen/NUyjXTCJjo7cJ6ejWUr2nIia8qOvAKNdLHr32Df6G8iaoaOx6pHaoiacwp26DaslxZHCGbibZhhCGven4rvmWP60GahtzgFjgCjR/0, createdBy=6b111703011, createdName=有备才能无患, createdTime=Wed Feb 14 22:27:53 CST 2018, time=2018-02-14, status=1, ipAttribution=)]
    2018-02-14 有备才能无患

    以呕血.便血的量作为估计失血量的资料.往往不太精确.因为一方面.呕血与便血常分别混有胃内容物与粪便,另一方面.部分血液尚贮留在胃肠道内.仍未排出体外.因此.失血量的估计可根据血容量减少导致周围循环的改变作出判断.

    0