On-line measurement of patient-ventilator fighting

✍ Scribed by Richard R. Mitchell; John C. Kunz; Maurice Lamy; Robert J. Fallat

• Book ID: 103052458
• Publisher: Elsevier Science
• Year: 1979
• Tongue: English
• Weight: 714 KB
• Volume: 12
• Category: Article
• ISSN: 0010-4809
• DOI: 10.1016/0010-4809(79)90030-2

✦ Synopsis

This paper describes an algorithm for on-line detection and quantitation of respiratory muscle usage during episodes of patient-ventilator fighting. Respiratory pressure and gas flow are measured at the mouth of patients receiving ventilatory assist and these data are processed by a computer to produce the FITE index. The mechanical properties of the pulmonary system are described by a mathematical model which assumes the respiratory muscles to be relaxed. Two model parameters, lung plus thoracic compliance and airway resistance, are estimated using a least squares approach, and the model predicted mouth pressure is computed. The fighting index is then defined as the root mean square .difference of the measured and computed mouth pressure. Application of the algorithm to patients in the intensive care unit shows that (1) the FITE index is a sensitive indicator for early detection of fighting and (2) a signilicant arterial blood pressure increase occurs with ventilator fighting.