Demand and continuous flow intermittent mandatory ventilation systems
| Autor: | Kent L. Christopher, Charles G. Irvin, Thomas A. Neff, James T. Good, James L. Bowman, Donald J. Eberle |
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| Rok vydání: | 1985 |
| Předmět: |
Pulmonary and Respiratory Medicine
Artificial ventilation medicine.medical_specialty medicine.medical_treatment Flow (psychology) Critical Care and Intensive Care Medicine law.invention Intermittent Positive-Pressure Ventilation Positive-Pressure Respiration Inspiratory flow law medicine Transducers Pressure Humans Lung Diseases Obstructive Intermittent Positive-Pressure Breathing Work of Breathing Intermittent mandatory ventilation Continuous flow business.industry Airway Resistance Respiration Exhalation Surgery Pressure measurement Evaluation Studies as Topic Acute Disease Cardiology and Cardiovascular Medicine business Pulmonary Ventilation Respiratory Insufficiency Biomedical engineering |
| Zdroj: | Chest. 87(5) |
| ISSN: | 0012-3692 |
| Popis: | A mechanical lung was used to evaluate the pressure and flow characteristics of four demand and two continuous flow intermittent mandatory ventilation (IMV) systems. The amount of negative pressure required to initiate inspiratory flow and peak expiratory resistance were measured. The inspiratory pressure required to initiate flow in the demand mode was also compared to pressures generated in the assist mode. In addition, the peak expiratory resistance was measured with four commercially available exhalation valves. Results showed that the ventilator manometer measuring internal machine pressures significantly underestimated the amount of negative pressure required to open the demand valve (p less than 0.01). There are major differences in the flow and pressure characteristics among demand and continuous flow IMV systems. Systems that impose high inspiratory elastic threshold loads and expiratory flow resistive loads may have a deleterious effect on the mechanics of breathing, and thereby limit weaning success and eventually impair the recovery of certain patients in respiratory failure. The basic methodology, especially the simple technique of inserting an aneroid manometer in line next to a patient's ET tube, for measuring proximal negative inspiratory force (NIF test) can be easily applied to any and all ventilators at any practitioner's individual institution. |
| Databáze: | OpenAIRE |
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