Capnography in mechanically ventilated patients

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“…Capnography has been considered a potentially useful noninvasive monitor to assess the weaning of patients from mechanical ventilation in critical care settings [40]. However, studies have shown variable results in the ability of PETCO 2 to predict PaCO 2 .…”

Combined Use of Transcutaneous and End-Tidal Measures of Carbon Dioxide to Predict PCO2 during General Anaesthesia in Adults

“…Monitoring the partial pressure of carbon dioxide (PCO 2 ) is an essential means of assessing alveolar ventilation in patients during anesthesia, procedural sedation and emergency care [1][2][3][4][5][6]. Although the arterial blood gas(ABG) measurement of PCO 2 (PaCO 2 ) is regarded as the gold standard technique for PCO 2 assessments [7][8][9], it is an invasive and painful method that requires arterial blood gas analysis.…”

“…These monitoring systems are noninvasive and display real-time data. PetCO 2 and respiratory waveforms from a capnograph can provide vital information about CO 2 retention and respiratory depression and can serve as an apnea monitor in spontaneously breathing patients [3,4,10]. PtcCO 2 sensors are not only widely used in neonatology and in critically ill infants but also used in adult patients during noninvasive mechanical ventilation, the transportation of critically ill adults, bronchoscopy etc [7,11,12].…”

The Precise Mechanisms of a High-Speed Ultrasound Gas Sensor and Detecting Human-Specific Lung Gas Exchange

“…Changes in gas substances peculiar to the human body, such as carbon dioxide, oxygen and humidified air, play an important role in the analysis of the physical state of a human body and decreasing cerebral functions [1][2][3][4][5][6][7][8]. A typical time constant (= time resolution) for commonly used medical human respiration sensing devices, e.g., the capnograph, is about 200 msec (e.g., TG-920P Nihon Koden co.).…”

“…They concluded that it was difficult to analyse asthma from the wave shape of the capnograph. They reported that there were slight second-order coefficient changes in the output CO2 pattern between healthy and asthma-suffering patients [1,5]. The typical gas sensing method of the capnograph adopts the measurement principle of InfraRed spectroscopy [7].…”