Authors:
Carmen Caroline Rasera
1
;
Pedro Miguel Gewehr
1
and
Adriana Maria T. Domingues
2
Affiliations:
1
Parana Federal University of Technology (UTFPR), Brazil
;
2
Pequeno Principe Hospital, Brazil
Keyword(s):
Monitoring Device, End-tidal Carbon Dioxide Pressure, Capnogram, Invasive Mechanical Ventilation.
Related
Ontology
Subjects/Areas/Topics:
Biomedical Engineering
;
Biomedical Equipment
;
Biomedical Instruments and Devices
;
Devices
;
Health Monitoring Devices
;
Human-Computer Interaction
;
Physiological Computing Systems
Abstract:
The monitoring of carbon dioxide pressure through Capnography has been clinically used as a continuous and non-invasive measurement of alveolar ventilation. The patients with lung disease, respiratory and hemodynamic instability and when in mechanical ventilation have a significant alteration in the waveform of the capnogram. In this study, quantitative analysis between capnographic indices of the patients under prolonged mechanical ventilation were obtained and compared to waveforms of spontaneously breathing patients. The measurements were performed at the 10th day of invasive mechanical ventilation and 48 hours after tracheal extubation, totalling 52 capnographic curves. PaCO2 and PetCO2 measurements maintained a significant correlation in spontaneously breathing patients (r2 = 0.97, p<0.001) and a weak correlation in patients during prolonged mechanical ventilation (r2 = 0.86). Four waveform parameters (intermediate slope, alpha angle, beta angle and area ratio) were identified a
s altered. These altered parameters can provide guidance to physicians about the physiological interpretation of capnograms and clinical decision. Proper interpretation of the capnogram can alert a clinician to important changes in mechanical ventilatory parameters in order to obtain a capnographic wave closest to normal thereby improving the lung function of patients.
(More)