心脏性猝死仍是威胁人类健康的重要急症。心搏骤停患者的生存预后与早期及时发现并启动急救反应密切相关,而心肺复苏质量的重要性与此等同[1]。动物和临床研究都证实心肺复苏质量能够显著影响生存预后[2, 3]。目前的心肺复苏技术仅能提供1/3左右的正常血供[4, 5],高质量实施心肺复苏至关重要。低质量的心肺复苏不但无法挽救患者生命,甚至带来更多的危害[6, 7]。因此,强调在心肺复苏过程中实施高质量的心肺复苏,是提高心脏性猝死患者抢救成功率的关键。
1 高质量的心肺复苏心搏骤停后自主循环的恢复(ROSC)取决于心肌的供氧和血流灌注情况。冠脉灌注压(CPP)是心肺复苏时心肌灌注的首要决定因素。心肺复苏同时产生最佳的CPP是心肺复苏的首要生理学目标[8]。然而,在实际工作中大部分患者的此项指标难以获得,因此大家更多的关注于其他的与心肺复苏预后明确相关的指标。大量的研究已经证实,高质量的心肺复苏应该包括以下几个方面[9]:快速、有力的按压,尽量减少按压中断,胸廓充分回弹,避免过度通气。
胸外按压是心肺复苏的关键,决定整个心肺复苏的质量。快速指的是胸外按压的频率应保持在100~120次/min[10];有力则是指胸外按压的深度在成人至少是5 cm,而婴儿和儿童至少为胸廓前后径的1/3[11]。尽管对于最佳的成人按压深度仍存争议,需要因人而异[12],但胸外按压的频率已被明确锁定在100~120次/min[13]。要保持良好的心肌灌注,维持一定的CPP,需要持续按压,尽量减少按压的中断[14]。临床中我们用胸外按压分数(CCF),即胸外按压占整个心肺复苏过程的时间比,来评价按压中断的程度[15],理想的CCF值应该超过80%。要有效提高CCF,就必须有效减少心律分析、除颤前后停止按压的时间[16, 17],同时提高抢救团队的合作效率,保证持续高质量胸外按压的同时,减少各种不必要的停顿和操作[18]。胸外按压时胸廓回弹不充分,是我们临床复苏中最常见的问题之一[19]。胸外按压时胸廓不能充分回弹会导致回心血量和心输出量的降低,并减少脑组织和心肌的灌注,影响复苏预后[20, 21]。因此,胸外按压时应该避免身体倾斜,保证胸廓充分回弹[22]。心肺复苏过程中的氧供非常重要,但只要保证高质量的胸外按压,给予基本的有效通气,即便是窒息原因引起的心搏骤停患者,也可获得足够的氧供[23]。而临床中我们最常见的问题不是氧供不足,而是通气过度[24]。研究证实,过快(超过12次/min)过猛(大潮气量或正压通气)的通气能够导致复苏过程中的血流动力学改变,引起不良反应,降低复苏成功率[25, 26, 27, 28]。因此,建议在心肺复苏时能够选择小潮气量(刚好可见胸廓起伏)、低通气频率(6~12次/min)且能与按压同步的通气策略[29]。
2 高质量的心肺复苏的实施无论国内外,临床实践当中的心肺复苏的质量与我们所熟知的理论知识(例如心肺复苏指南)间还存在着巨大的差距[29, 30, 31]。那我们该如何去弥合两者间的差距呢?或者说,如何才能实施高质量的心肺复苏?
2.1 建立科学、完善的培训体系培训能够显著提高医务人员心肺复苏的质量,让学员更快、更好的掌握心肺复苏的技术[32, 33, 34]。但医学培训和教育一直是我们最大的短板,针对大众的医学普及培训更是凤毛麟角。可喜的是,美国心脏协会心血管急救课程已经成功引入国内6年,这极大地改变了国内心肺复苏培训的理念、模式和效果,正在使越来越多大中城市的医务工作者和普通市民接受到规范化的心肺复苏知识和技能的培训。这种以视频和模拟教学为基础,强调高质量复苏理念和临床实践能力的培训模式已经为大量研究证实是最有效的心肺复苏技能培训的方式之一[35]。然而,这种培训的规模仍远远不能满足实际的临床需求,尤其是在中小城市和广大的农村、偏远地区。更令人遗憾的是,国内很多只重形式、不懂内涵的心肺复苏培训仍占主流,绝大多数的一线医务人员仍然缺乏基本的复苏知识和技术的更新和培训,这也成为阻碍我国心肺复苏水平提高的重要瓶颈之一。站在更高的层面,建立全面、科学的心肺复苏教育和培训体系,让中国的医护人员以及普通大众真正掌握正确的心肺复苏知识和技术,通过培训使他们能够及早识别心搏骤停,敢于在现场实施有效的心肺复苏,是我们需要真正迈出的第一步。
在北美地区,执业医师、护士已经被要求每两年必须参加心肺复苏知识和技术的更新和复训,培训获得的合格证书是执业资格延续的必要条件,这种做法值得我们借鉴。而从事急诊、危重症和心血管专业的医务工作者,培训的周期应该更短。最新的研究就表明,为期三个月的心肺复苏培训周期能够使医务人员显著提高并维持心肺复苏操作的质量[36]。
2.2 强调并应用团队复苏的理念无论在院前或院内,团队抢救是心肺复苏最重要的组织形式[37]。团队复苏能够显著改善心肺复苏的质量,尤其是增加CCF[38]。心肺复苏时的团队理念精髓是要求在充分保证按压和通气的前提下,利用各种可利用的工具和资源,通过明确的分工和紧密的团队配合,实施高质量的心肺复苏[39]。团队复苏的目标就是心肺复苏的质量,要根据患者、环境、病因等的不同,通过团队努力,使上述体现心肺复苏质量的各项指标最佳化。但很多人错误地将团队复苏理解为运用各种手段、药物,穷尽其技术进行各种抢救的尝试(包括气管插管等),这完全背离了团队复苏的宗旨和目的,不但耽误了抢救的时间,还严重降低了心肺复苏的质量。此外,抢救后的及时总结作为团队复苏的另一项重要工作,往往被忽视甚至是省略。无论抢救成功与否,及时的分析、小结有助于团队成员不断改善心肺复苏的质量,提高抢救成功率。团队复苏还为心肺复苏时实施质量监控提供可能,团队成员可以相互督促,提醒,改善技术质量,足够的人力使得各种最新的监测和反馈技术能够及时应用于临床,帮助团队更加客观、准确的评估实时心肺复苏质量[40]。当然,成功、有效应用团队复苏需要建立在良好的培训和组织基础之上[41],因此要重视急诊模拟医学教育的建设和发展。
2.3 重视心肺复苏实施的质量监测与反馈最简单、直接的监测技术就是施救者本人或团队成员通过观察,凭借训练和抢救的经验评估心肺复苏的质量,再联合患者面色改变、大动脉搏动、瞳孔改变等情况综合评价心肺复苏实施的质量,并通过相互提醒提供信息反馈。但这样的监测显然不够客观、准确,事实上也效果不佳[42]。随着大家对心肺复苏质量的重视,大量的质量监测技术已经成功转化为临床可用的成熟产品,而这些监测和反馈技术无论是在临床实践和培训中都被证实能够显著改善心肺复苏的质量,提高患者的生存预后[43, 44, 45, 46]。
目前监测心肺复苏质量的方法和技术主要包括三类[29, 47]:第一类是能够直接反映心肺复苏的效果的技术。CPP是最经典的指标,也是心肺复苏质量评价的“金标准”,但在临床实践中常难以获得,通常建议以舒张期的有创动脉血压作为参考和替代。呼气末二氧化碳波形图是国际复苏指南的重点推荐,能够很好地反映人工循环时的心排水平,还可确定高级气道的放置位置和ROSC,是不错的监测指标,但前提是需要建立高级气道。心电图波形分析也是经典的评价指标之一,反映的是心肌灌注及电活动的状态,作为除颤时机的判断指标更为合适。脑部血氧饱和度监测提供了一种全新的无创监测心肺复苏质量的方法[48],可以了解心肺复苏过程中实时的脑灌注及脑组织供氧情况,但还需要进一步的临床验证。第二类也是目前最常用的就是心肺复苏实施技术的监测,包括按压深度、频率,胸廓回弹、CCF等指标,系统还可提供实时的语音或图文的反馈提示。该类技术主要通过测量按压位置的加速度改变或者胸部阻抗等参数的改变来测算,精度和准确度也在不断提高。而且这类数据能够完整被记录,还可用作复苏后的小结和质量分析的研究。第三类技术虽不能直接反映复苏质量,却能显著改善心肺复苏的质量[49]。例如心电滤波技术能够将按压干扰波形从心电监测的波形中滤除,在无需停止按压的情况下,即可判断心律失常类型,可显著提高CCF,提高除颤成功率。血氧饱和度监测易受环境温度、患者外周循环等条件影响,并不是良好的质量监测指标,但联合与心电图协同,却能很好地判定复苏后ROSC。
随着科技的发展,心肺复苏的质量监测技术和手段会更加准确和多样,最新的技术已经让智能手机成为心肺复苏质量监测的工具[50],常规进行质量监测必然会成为今后的发展趋势[45]。
2.4 及时总结,持续提高心肺复苏的质量持续质量改进(CQI)在卫生领域广泛应用,能够显著提高医疗质量[51]。同样,心肺复苏质量的提高同样需要CQI。心肺复苏抢救结束应该及时进行小结,重点对患者的实际情况和抢救人员的心肺复苏表现进行回顾分析,提出今后可以改进的环节和措施,这是快速提高团队心肺复苏质量的重要手段,能够显著提高患者的出院生存率[52, 53, 54]。如果能将心肺复苏的抢救记录、心肺复苏质量的监测数据充分应用分析,再结合现有培训、临床流程设计可能存在的问题等综合考虑分析,进行系统性改进和提高,并坚持不断的优化与改进,才可能真正推动心肺复苏质量的不断提高,完善生存链的各个环节,最终提高我国心肺复苏的抢救成功率。
质量就是生命,对从事心肺复苏的医务人员来说最贴切不过。临床实践一再提醒我们:指南并不完美,临床应因人而异。临床指南5年一次的修订周期已经明显落后于各种新理论、新技术及其临床证据的更新与进步,而众所周知的单纯用一个标准来统一指导不同人种、人口和地区等各种不同条件下临床患者的抢救本身就会带来诸多的问题和麻烦。再加之循证医学的论证要求,很多在大动物实验身上被验证的科学不得不再等待几年甚至几十年的时间“转化于”临床,直至大规模的前瞻性随机对照多中心临床研究来再次证明其“科学性”,才使得这些陈年的新技术和理论重见天日。或许在对《指南》不断抱怨又期盼的矛盾中,我们真应静下心来认真思考,我们自己手头还有哪些工具和资源可以充分加以利用,在不断提高自己的每一个患者的心肺复苏质量的同时,如何在实践和探索中不断提高我国的心肺复苏的临床和科研水平。
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