正常自主呼吸 正常机械通气
ቤተ መጻሕፍቲ ባይዱ
Capnograph of a patient with severe chronic obstructive pulmonary disease. No plateau is reached before the next inspiration. The gradient between end-tidal CO2 and arterial CO2 is increased.
呼末二氧化碳分压曲线 Capnography
测定原理
红外线法,质谱仪法和比色法 最常用的是红外线吸收光谱技术,
是基于红外光通过检测气样时,其吸 收率与二氧化碳浓度相关的原理CO2 主要吸收波长为4260nm的红外光
测定方法
主流取样:
反应快 沉,易发热 增加死腔量 (老传感器)
侧孔取样:
Failure of the inspired CO2 to return to zero may represent an incompetent expiratory valve or exhausted CO2 absorbent
Depression during phase III indicates spontaneous respiratory effort
Cardiogenic oscillations, when seen, usually occur on sidestream capnographs of spontaneously breathing patients at the end of each exhalation. Cardiac action causes to-and-fro movement of the interface between exhaled and fresh gas.