Biomaterial Database

Transpulmonary Pressure Describes Lung Morphology During Decremental Positive End-Expiratory Pressure Trials in Obesity. 2017

Jacopo Fumagalli, and Lorenzo Berra, and Changsheng Zhang, and Massimiliano Pirrone, and Roberta R De Santis Santiago, and Susimeire Gomes, and Federico Magni, and Glaucia A B Dos Santos, and Desmond Bennett, and Vinicius Torsani, and Daniel Fisher, and Caio Morais, and Marcelo B P Amato, and Robert M Kacmarek

1Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA.2Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Universita' degli Studi di Milano, Milan, Italy.3Pulmonary Division, Heart Institute, School of Medicine, University of São Paulo, São Paulo, Brazil.4Dipartimento di Medicina e Chirurgia, Universita' degli Studi di Milano-Bicocca, Milan, Italy.5Hospital das Clínicas da Faculdade de Medicina da USP (HCFMUSP)-Instituto de Radiologia (InRad), Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.6Respiratory Care Department, Massachusetts General Hospital, Boston, MA.

OBJECTIVE Atelectasis develops in critically ill obese patients when undergoing mechanical ventilation due to increased pleural pressure. The current study aimed to determine the relationship between transpulmonary pressure, lung mechanics, and lung morphology and to quantify the benefits of a decremental positive end-expiratory pressure trial preceded by a recruitment maneuver. METHODS Prospective, crossover, nonrandomized interventional study. METHODS Medical and Surgical Intensive Care Units at Massachusetts General Hospital (Boston, MA) and University Animal Research Laboratory (São Paulo, Brazil). METHODS Critically ill obese patients with acute respiratory failure and anesthetized swine. METHODS Clinical data from 16 mechanically ventilated critically ill obese patients were analyzed. An animal model of obesity with reversible atelectasis was developed by placing fluid filled bags on the abdomen to describe changes of lung mechanics, lung morphology, and pulmonary hemodynamics in 10 swine. RESULTS In obese patients (body mass index, 48 ± 11 kg/m), 21.7 ± 3.7 cm H2O of positive end-expiratory pressure resulted in the lowest elastance of the respiratory system (18.6 ± 6.1 cm H2O/L) after a recruitment maneuver and decremental positive end-expiratory pressure and corresponded to a positive (2.1 ± 2.2 cm H2O) end-expiratory transpulmonary pressure. Ventilation at lowest elastance positive end-expiratory pressure preceded by a recruitment maneuver restored end-expiratory lung volume (30.4 ± 9.1 mL/kg ideal body weight) and oxygenation (273.4 ± 72.1 mm Hg). In the swine model, lung collapse and intratidal recruitment/derecruitment occurred when the positive end-expiratory transpulmonary pressure decreased below 2-4 cm H2O. After the development of atelectasis, a decremental positive end-expiratory pressure trial preceded by lung recruitment identified the positive end-expiratory pressure level (17.4 ± 2.1 cm H2O) needed to restore poorly and nonaerated lung tissue, reestablishing lung elastance and oxygenation while avoiding increased pulmonary vascular resistance. CONCLUSIONS In obesity, low-to-negative values of transpulmonary pressure predict lung collapse and intratidal recruitment/derecruitment. A decremental positive end-expiratory pressure trial preceded by a recruitment maneuver reverses atelectasis, improves lung mechanics, distribution of ventilation and oxygenation, and does not increase pulmonary vascular resistance.

UI	MeSH Term	Description	Entries
D007362	Intensive Care Units	Hospital units providing continuous surveillance and care to acutely ill patients.	ICU Intensive Care Units,Intensive Care Unit,Unit, Intensive Care
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D009765	Obesity	A status with BODY WEIGHT that is grossly above the recommended standards, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).
D011446	Prospective Studies	Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.	Prospective Study,Studies, Prospective,Study, Prospective
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
D004195	Disease Models, Animal	Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases.	Animal Disease Model,Animal Disease Models,Disease Model, Animal
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001261	Pulmonary Atelectasis	Absence of air in the entire or part of a lung, such as an incompletely inflated neonate lung or a collapsed adult lung. Pulmonary atelectasis can be caused by airway obstruction, lung compression, fibrotic contraction, or other factors.	Atelectasis, Congestive,Lung Collapse,Atelectasis,Compression Atelectasis,Compression Pulmonary Atelectasis,Congestive Atelectasis,Congestive Pulmonary Atelectasis,Contraction Pulmonary Atelectasis,Postoperative Pulmonary Atelectasis,Resorption Atelectasis,Resorption Pulmonary Atelectasis,Atelectases,Atelectases, Compression,Atelectases, Compression Pulmonary,Atelectases, Congestive,Atelectases, Congestive Pulmonary,Atelectases, Contraction Pulmonary,Atelectases, Postoperative Pulmonary,Atelectases, Pulmonary,Atelectases, Resorption,Atelectases, Resorption Pulmonary,Atelectasis, Compression,Atelectasis, Compression Pulmonary,Atelectasis, Congestive Pulmonary,Atelectasis, Contraction Pulmonary,Atelectasis, Postoperative Pulmonary,Atelectasis, Pulmonary,Atelectasis, Resorption,Atelectasis, Resorption Pulmonary,Collapse, Lung,Compression Atelectases,Compression Pulmonary Atelectases,Congestive Atelectases,Congestive Pulmonary Atelectases,Contraction Pulmonary Atelectases,Postoperative Pulmonary Atelectases,Pulmonary Atelectases,Pulmonary Atelectases, Compression,Pulmonary Atelectases, Congestive,Pulmonary Atelectases, Contraction,Pulmonary Atelectases, Postoperative,Pulmonary Atelectases, Resorption,Pulmonary Atelectasis, Compression,Pulmonary Atelectasis, Congestive,Pulmonary Atelectasis, Contraction,Pulmonary Atelectasis, Postoperative,Pulmonary Atelectasis, Resorption,Resorption Atelectases,Resorption Pulmonary Atelectases
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog