Biomaterial Database

Change in the work of breathing imposed by five anaesthetic breathing systems. 1983

B Kay, and P C Beatty, and T E Healy, and M E Accoush, and M Calpin

Measurements of pressure and flow in five anaesthetic breathing systems were studied with various fresh gas flows (FGF) using volunteers, and mechanically simulated breathing. Pressure measurements were made at the patient connection and in the neck of the reservoir bag. A pneumotachograph was used to measure flow in the patient connection. The change in the work of breathing imposed by the circuit was derived from the pressure-volume graph and apportioned to stages of the breathing cycle. All the systems studied increased the work of breathing. Expiratory work was always increased more than inspiratory work. The additional work imposed on expiration and the total extra work imposed on breathing were further increased at FGF greater than the minimum clinical requirement.

UI	MeSH Term	Description	Entries
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D012122	Ventilators, Mechanical	Mechanical devices used to produce or assist pulmonary ventilation.	Mechanical Ventilator,Mechanical Ventilators,Respirators,Ventilators, Pulmonary,Pulmonary Ventilator,Pulmonary Ventilators,Ventilator, Pulmonary,Ventilators,Respirator,Ventilator,Ventilator, Mechanical
D012123	Pulmonary Ventilation	The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.	Respiratory Airflow,Ventilation Tests,Ventilation, Pulmonary,Expiratory Airflow,Airflow, Expiratory,Airflow, Respiratory,Test, Ventilation,Tests, Ventilation,Ventilation Test
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000769	Anesthesia, Inhalation	Anesthesia caused by the breathing of anesthetic gases or vapors or by insufflating anesthetic gases or vapors into the respiratory tract.	Insufflation Anesthesia,Anesthesia, Insufflation,Inhalation Anesthesia
D014939	Work of Breathing	RESPIRATORY MUSCLE contraction during INHALATION. The work is accomplished in three phases: LUNG COMPLIANCE work, that required to expand the LUNGS against its elastic forces; tissue resistance work, that required to overcome the viscosity of the lung and chest wall structures; and AIRWAY RESISTANCE work, that required to overcome airway resistance during the movement of air into the lungs. Work of breathing does not refer to expiration, which is entirely a passive process caused by elastic recoil of the lung and chest cage. (Guyton, Textbook of Medical Physiology, 8th ed, p406)	Breathing Work,Breathing Works