Biomaterial Database

Optimal constant positive airway pressure assessed by arterial alveolar difference for CO2 in hyaline membrane disease. 1986

S Landers, and T N Hansen, and A J Corbet, and M J Stevener, and A J Rudolph

In a group of infants with hyaline membrane disease, the level of optimal constant positive airway pressure (CPAP) was assessed by raising CPAP in small steps from an initial low value, and after each change measuring the arterial alveolar difference for CO2 (aADCO2) and transmission of airway pressure to the esophagus. Below optimal CPAP there was a progressive increase in mixed alveolar partial pressure of CO2 (PACO2) and no change in arterial partial pressure of CO2 (PaCO2), so that aADCO2 declined and reached a lowest value at optimal CPAP. Correspondingly, transmission of airway pressure increased progressively and reached a highest value at optimal CPAP. Between 1 step below and optimal CPAP, PACO2 rose from 30.9 to 34.0 torr, and aADCO2 declined from 16.6 to 12.7 torr. Between optimal and 1 step above optimal CPAP, PaCO2 increased from 46.7 to 51.0 torr, PACO2 rose slightly, and aADCO2 increased from 12.7 to 15.6 torr. Thus, the aADCO2 was an excellent index of optimal CPAP. In five patients with measurements of PaO2 at constant fractional inspired oxygen, calculated values for arterial oxygen saturation changed from 80.8 to 91.5 to 92.2%, and calculated values for venous admixture changed from 0.61 to 0.48 to 0.46 as CPAP was raised from 1 step below through optimal to 1 step above optimal CPAP. The results are interpreted to mean a progressive improvement in perfusion of well ventilated lung units as CPAP increased to optimal levels, but a significant reduction of both ventilation and perfusion above optimal CPAP.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D007231	Infant, Newborn	An infant during the first 28 days after birth.	Neonate,Newborns,Infants, Newborn,Neonates,Newborn,Newborn Infant,Newborn Infants
D010100	Oxygen	An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.	Dioxygen,Oxygen-16,Oxygen 16
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
D011650	Pulmonary Alveoli	Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place.	Alveoli, Pulmonary,Alveolus, Pulmonary,Pulmonary Alveolus
D011652	Pulmonary Circulation	The circulation of the BLOOD through the LUNGS.	Pulmonary Blood Flow,Respiratory Circulation,Circulation, Pulmonary,Circulation, Respiratory,Blood Flow, Pulmonary,Flow, Pulmonary Blood,Pulmonary Blood Flows
D012129	Respiratory Function Tests	Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.	Lung Function Tests,Pulmonary Function Tests,Function Test, Pulmonary,Function Tests, Pulmonary,Pulmonary Function Test,Test, Pulmonary Function,Tests, Pulmonary Function,Function Test, Lung,Function Test, Respiratory,Function Tests, Lung,Function Tests, Respiratory,Lung Function Test,Respiratory Function Test,Test, Lung Function,Test, Respiratory Function,Tests, Lung Function,Tests, Respiratory Function
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006819	Hyaline Membrane Disease	A respiratory distress syndrome in newborn infants, usually premature infants with insufficient PULMONARY SURFACTANTS. The disease is characterized by the formation of a HYALINE-like membrane lining the terminal respiratory airspaces (PULMONARY ALVEOLI) and subsequent collapse of the lung (PULMONARY ATELECTASIS).	Disease, Hyaline Membrane,Diseases, Hyaline Membrane,Hyaline Membrane Diseases
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations