Capnography

BACKGROUND: Differentiating between cardiac and obstructive causes for dyspnoea is essential for proper management, but is difficult in the prehospital setting. OBJECTIVE: To assess if prehospital levels of end-tidal carbon dioxide (ETCO2) differed in obstructive compared to cardiac causes of dyspnoea, and could suggest one diagnosis over the other. METHODS: We conducted a retrospective cohort study among patients transported by emergency medical services during a 29-month period who were diagnosed with either obstructive pulmonary disease or congestive heart failure (CHF) by ICD-9 codes...

Modern ventilators provide capnography monitoring in patients with tracheal tubes, in compliance with national and international recommendations. This technology is often not used when patients' lungs are non-invasively ventilated; however, it should be accessed immediately following tracheal intubation to confirm tube placement. This study assessed the effect of ventilation interface design on the speed with which capnography can be activated by comparing the Dräger Evita 4 and Dräger V500 before and after a specific training episode...

No abstract text is available yet for this article.

No abstract text is available yet for this article.

No abstract text is available yet for this article.

The aim of this study was to investigate why capnographs malfunction at high altitude, in order to suggest ways of improving instrument reliability. Four machines were decompressed to simulated high altitude and measurements taken. The study showed that the reduced air density at altitude has effects upon the pump, causing difficulty in entraining gas, and that high altitude has additional effects upon calibration of the instruments.

Measurement of the end-tidal partial pressure of carbon dioxide (PET CO2 ) during cardiac arrest has been shown to reflect the blood flow being generated by external means and to prognosticate outcome. In the present issue of Critical Care , Grmec and colleagues compared the initial and subsequent PET CO2 in patients who had cardiac arrest precipitated by either asphyxia or ventricular arrhythmia. A much higher PET CO2 was found immediately after intubation in instances of asphyxial arrest. Yet, after 1 min of closed-chest resuscitation, both groups had essentially the same PET CO2 , with higher levels in patients who eventually regained spontaneous circulation...

OBJECTIVE: Determine whether end-tidal CO(2) (ETCO(2)) monitoring allows for more rapid discrimination of tracheal versus esophageal intubation than standard clinical assessment during neonatal resuscitation in the delivery room. STUDY DESIGN: Endotracheal tube (ETT) placement was assessed using either a hand-held monitor that displayed graphic and quantitative ETCO(2) by an investigator not involved in the resuscitation, or using clinical parameters by the resuscitation team unaware of the ETCO(2) data...

The measurement of the pressure of exhaled carbon dioxide (PetCO2) via capnography has several useful hemodynamic applications. This article discusses integrating PetCO2 values with hemodynamic assessment. Capnography can be applied to hemodynamic assessment in three key ways: (1) identification of end-expiration during pulmonary artery and central venous pressure measurements, (2) assessment of pulmonary perfusion and alveolar deadspace, (3) assessment of cardiopulmonary resuscitative efforts. The article presents research, sample waveforms for end-expiration identification, and case examples...

Greater understanding of the pathophysiology of carbon dioxide kinetics during steady and nonsteady state should improve, we believe, clinical care during intensive care treatment. Capnography and the measurement of end-tidal partial pressure of carbon dioxide (PETCO2) will gradually be augmented by relatively new measurement methodology, including the volume of carbon dioxide exhaled per breath (VCO2,br) and average alveolar expired PCO2. Future directions include the study of oxygen kinetics.

The anesthetist will get the most information out of a capnograph if it is examined systematically. First, the anesthetist must determine whether exhaled CO2 (i.e., a waveform) is present. The differential diagnosis of absent CO2 includes esophageal intubation, accidental tracheal extubation, disconnection of the breathing circuit, complete obstruction of the endotracheal tube or conducting system (kink, inspissated blood or secretions, extremely severe bronchospasm) or of the breathing circuit, apnea, and cardiac arrest...

OBJECTIVE: To examine the feasibility of using expiratory capnography as an indicator of airway obstruction in non-intubated resuscitation room patients. METHODS: Patients with potential respiratory compromise admitted to the resuscitation room were assessed for widespread expiratory wheeze. This was taken as clinical evidence of airways obstruction. Expiratory capnograms of these patients and patients who had no wheeze were obtained. The traces were analysed for basic morphology and where appropriate the slope ratio (SR) between phase 1 (S1) and phase 2 (S2) of the trace was obtained...

Previous studies have reported mixed results when correlating etCO2 and PaCO2 in mechanically ventilated patients with underlying respiratory disease. However, the utility and accuracy of capnography in nonintubated patients, without chronic pulmonary disease, has received little attention. We studied 25 nonintubated surgical patients to (1) examine the correlation between PaCO2 and etCO2 and (2) describe the relationship between dead space (VD/VT), venous admixture and P(a-et)CO2. End tidal CO2 was lower than PaCO2 by an average of 3...