CAJ | 학술논문

背景容量-呼气末二氧化碳分压图（volume-capnogram，v-PETCO2）是根据呼吸周期中呼出气量对应CO2水平描记的单波图，是评价呼吸障碍患者死腔或分流的最有价值的无创性新工具。目的讲述v-PETCO2的基本原理、正常波形和异常波形的临床意义。内容v-PETCO2波的形态取决于CO2产生、运输（肺灌注）和弥散以及任何原因引起的肺病理生理学改变，可用来更好地了解和研究CO2动力学过程。v-PETCO2有3个呼气相：相Ⅰ，呼出的为无CO2的气道气体，相Ⅱ是气道和肺泡混合气体，相Ⅲ完全是肺泡气体。呼吸障碍时通气/灌注比率不匹配，导致肺泡序贯性排空，呼出气CO2水平不同，v-PETCO2波的相Ⅲ斜率增加，解剖死腔、肺泡死腔和/或生理死腔及及其计算参数增加。根据v -PETCO2波的相Ⅲ斜率能将肺栓塞与肺疾患轻易区别，通过死腔参数较精确地评价急性呼吸窘迫综合征(acute respiratory distresssyndrome，ARDS)、哮喘、慢性阻塞性肺病(chronic obstructive pulmonary diseases，COPD)等严重程度和鉴别。趋向PETCO2波对危重患者肺功能临床评价和研究具有突破性贡献和非常高的价值。
배경용량-호기말이양화탄분압도（volume-capnogram，v-PETCO2）시근거호흡주기중호출기량대응CO2수평묘기적단파도，시평개호흡장애환자사강혹분류적최유개치적무창성신공구。목적강술v-PETCO2적기본원리、정상파형화이상파형적림상의의。내용v-PETCO2파적형태취결우CO2산생、운수（폐관주）화미산이급임하원인인기적폐병리생이학개변，가용래경호지료해화연구CO2동역학과정。v-PETCO2유3개호기상：상Ⅰ，호출적위무CO2적기도기체，상Ⅱ시기도화폐포혼합기체，상Ⅲ완전시폐포기체。호흡장애시통기/관주비솔불필배，도치폐포서관성배공，호출기CO2수평불동，v-PETCO2파적상Ⅲ사솔증가，해부사강、폐포사강화/혹생리사강급급기계산삼수증가。근거v -PETCO2파적상Ⅲ사솔능장폐전새여폐질환경역구별，통과사강삼수교정학지평개급성호흡군박종합정(acute respiratory distresssyndrome，ARDS)、효천、만성조새성폐병(chronic obstructive pulmonary diseases，COPD)등엄중정도화감별。추향PETCO2파대위중환자폐공능림상평개화연구구유돌파성공헌화비상고적개치。
Background Volume PETCO2 is a sigal-wave plot based on the expired carbon dioxide fraction,which is the standard tool for understanding carbon dioxide elimination and the dead space. Objective The basic principles and clinical significance of normal and abnormal waveform of v-PETCO2 is introduced. Content v-PETCO2 wave morphology depends on production, transport (pulmonary perfusion) and diffusion of the carbon dioxide, as well as any changes in respiratory pathophysiology, v-PETCO2 can be used to study the dynamics of CO2. This plot yields three parts: first phase is carbon dioxide free;phase Ⅱ represents the transition between gas from the airways and alveolar gas, and phase Ⅲ represents alveolar gas. The respiratory dysfunction reduces ventilation in some units more than others, causing an increased scatter of ventilation/perfusion (V/Q)ratios and thus of the range of alveolar PCO2 values. They results in increased slope of phase 3 and three dead space estimates derived from the v-capnogram, including the anatomical dead space, alveolar dead space and physiological dead space. This can differentiate a patient with a pulmonary embolism from a healthy patient or a COPD, ARDS or asthma patients. Trend v-PETCO2 is the standard tool for understanding carbon dioxide elimination and the dead space concept.