Variability of patient-ventilator interaction with pressure support ventilation in patients with chronic obstructive pulmonary disease. 1995

A Jubran, and W B Van de Graaff, and M J Tobin
Division of Pulmonary and Critical Care Medicine, Edward Hines, Jr. Veterans Administration Hospital, Loyola University of Chicago Stritch School of Medicine, Hines, Illinois 60141, USA.

In 12 patients with chronic obstructive pulmonary disease (COPD) receiving pressure support ventilation (PSV), we studied the variability of respiratory muscle unloading and defined its physiologic determinants using a modified pressure-time product (PTP). Inspiratory PTP/min decreased as PSV was increased (p < 0.001), but there was considerable interindividual variation: coefficients of variations of up to 96%. On multiple linear regression analysis, 73 to 83% of the variability in inspiratory PTP was explained by inspiratory resistance, minute ventilation, and intrinsic positive end-expiratory pressure. Taking an inspiratory PTP/min of < 125 cm H2O.sec/min to represent a desirable level of inspiratory effort during PSV, a respiratory frequency of < or = 30 breaths/min was more accurate than a tidal volume > 0.6 L in predicting this threshold (p < 0.001). At PSV of 20 cm H2O, expiratory effort, quantitated by an expiratory PTP, was clearly evident in five patients before the cessation of inspiratory flow, signifying that the patient was "fighting" the ventilator; of note, these five patients had a frequency of < or = 30 breaths/min. In conclusion, patient-ventilator interactions in patients with COPD are complex, and events in expiration need to be considered in addition to those of inspiration.

UI MeSH Term Description Entries
D008173 Lung Diseases, Obstructive Any disorder marked by obstruction of conducting airways of the lung. AIRWAY OBSTRUCTION may be acute, chronic, intermittent, or persistent. Obstructive Lung Diseases,Obstructive Pulmonary Diseases,Lung Disease, Obstructive,Obstructive Lung Disease,Obstructive Pulmonary Disease,Pulmonary Disease, Obstructive,Pulmonary Diseases, Obstructive
D008297 Male Males
D012121 Respiration, Artificial Any method of artificial breathing that employs mechanical or non-mechanical means to force the air into and out of the lungs. Artificial respiration or ventilation is used in individuals who have stopped breathing or have RESPIRATORY INSUFFICIENCY to increase their intake of oxygen (O2) and excretion of carbon dioxide (CO2). Ventilation, Mechanical,Mechanical Ventilation,Artificial Respiration,Artificial Respirations,Mechanical Ventilations,Respirations, Artificial,Ventilations, Mechanical
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
D012131 Respiratory Insufficiency Failure to adequately provide oxygen to cells of the body and to remove excess carbon dioxide from them. (Stedman, 25th ed) Acute Hypercapnic Respiratory Failure,Acute Hypoxemic Respiratory Failure,Hypercapnic Acute Respiratory Failure,Hypercapnic Respiratory Failure,Hypoxemic Acute Respiratory Failure,Hypoxemic Respiratory Failure,Respiratory Depression,Respiratory Failure,Ventilatory Depression,Depressions, Ventilatory,Failure, Hypercapnic Respiratory,Failure, Hypoxemic Respiratory,Failure, Respiratory,Hypercapnic Respiratory Failures,Hypoxemic Respiratory Failures,Respiratory Failure, Hypercapnic,Respiratory Failure, Hypoxemic,Respiratory Failures
D012132 Respiratory Muscles These include the muscles of the DIAPHRAGM and the INTERCOSTAL MUSCLES. Ventilatory Muscles,Respiratory Muscle,Muscle, Respiratory,Muscle, Ventilatory,Muscles, Respiratory,Muscles, Ventilatory,Ventilatory Muscle
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000368 Aged A person 65 years of age or older. For a person older than 79 years, AGED, 80 AND OVER is available. Elderly
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
D015656 Respiratory Mechanics The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc. Breathing Mechanics,Breathing Mechanic,Mechanic, Breathing,Mechanic, Respiratory,Mechanics, Breathing,Mechanics, Respiratory,Respiratory Mechanic

Related Publications

A Jubran, and W B Van de Graaff, and M J Tobin
January 2006, Critical care (London, England),
A Jubran, and W B Van de Graaff, and M J Tobin
November 2014, Critical care (London, England),
A Jubran, and W B Van de Graaff, and M J Tobin
January 1997, The European respiratory journal,
A Jubran, and W B Van de Graaff, and M J Tobin
January 2008, Respiration; international review of thoracic diseases,
Copied contents to your clipboard!