Biomaterial Database

Lung mechanics with relation to pulmonary haemodynamics, gas exchange and extravascular lung water in mechanically ventilated endotoxaemic pigs. 1986

P Forsgren, and J Modig

In a porcine model employing a continuous i.v. infusion of E. coli endotoxin the pathophysiology of early adult respiratory distress syndrome was studied with main emphasis on the early changes in lung mechanics and their relation to changes in pulmonary haemodynamics, gas exchange and extravascular lung water in intermittent positive pressure ventilated (IPPV) pigs under ketamine anaesthesia. Six animals served as controls and revealed no major physiological changes. Nine animals received endotoxin and developed significant changes in lung mechanics with increases in end-inspiratory pressure (32%), expiratory resistance (29%) and decrease in total dynamic lung compliance (27%). Changes in dynamic compliance and pulmonary haemodynamics displayed a 2-phase reaction. Venous admixture showed a rapid increase at with the increase in mean pulmonary arterial pressure (r = -0.8) and with the increase in venous admixture (r = -0.7). Extravascular lung water did not increase significantly. The decrease in dynamic compliance is most likely explained by peripheral airway constriction. A contributory factor might be pulmonary microvascular constriction with vascular stasis and mechanical compression of small airways. The increased venous admixture is best explained by a bronchiolar and microvascular constriction, i.e. a "dry" ventilation/perfusion inequality and not consequent to oedema. IPPV seems to counteract the increase in extravascular lung water.

UI	MeSH Term	Description	Entries
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008297	Male		Males
D010313	Partial Pressure	The pressure that would be exerted by one component of a mixture of gases if it were present alone in a container. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Partial Pressures,Pressure, Partial,Pressures, Partial
D011659	Pulmonary Gas Exchange	The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.	Exchange, Pulmonary Gas,Gas Exchange, Pulmonary
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
D012128	Respiratory Distress Syndrome	A syndrome characterized by progressive life-threatening RESPIRATORY INSUFFICIENCY in the absence of known LUNG DISEASES, usually following a systemic insult such as surgery or major TRAUMA.	ARDS, Human,Acute Respiratory Distress Syndrome,Adult Respiratory Distress Syndrome,Pediatric Respiratory Distress Syndrome,Respiratory Distress Syndrome, Acute,Respiratory Distress Syndrome, Adult,Respiratory Distress Syndrome, Pediatric,Shock Lung,Distress Syndrome, Respiratory,Distress Syndromes, Respiratory,Human ARDS,Lung, Shock,Respiratory Distress Syndromes,Syndrome, Respiratory Distress
D004731	Endotoxins	Toxins closely associated with the living cytoplasm or cell wall of certain microorganisms, which do not readily diffuse into the culture medium, but are released upon lysis of the cells.	Endotoxin
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005110	Extracellular Space	Interstitial space between cells, occupied by INTERSTITIAL FLUID as well as amorphous and fibrous substances. For organisms with a CELL WALL, the extracellular space includes everything outside of the CELL MEMBRANE including the PERIPLASM and the cell wall.	Intercellular Space,Extracellular Spaces,Intercellular Spaces,Space, Extracellular,Space, Intercellular,Spaces, Extracellular,Spaces, Intercellular
D005260	Female		Females