Biomaterial Database

[Effect of background flow on the accuracy of respiratory flow and respiratory volume measurement in newborn infants]. 1995

B Foitzik, and G Schmalisch, and R R Wauer

Abteilung Neonatologie, Klinik und Poliklinik für Kinderheilkunde.

Measurement of ventilation, in particular in preterm infants, is greatly impaired by equipment dead space, with its significant effect on the ventilatory pattern and gas exchange. For patients of this age, therefore, dead-spacefree methods are needed for long-term measurements. Rebreathing can be avoided if the pneumotachograph (PNT) and face mask are flushed with a continuous background flow. The effect of this on the measurements has not yet been investigated in detail. A measuring system comprising two identical baby PNTs (Jaeger/Germany) permitting a background flow of between 0 and 7 l per min was used. Spontaneous breathing was simulated with a 100 ml calibration syringe employing volumes of 20, 40, 60 and 100 ml (Rudolph/USA) and a frequency of 30 min-1. The measurements were carried out with a T-piece from a respirator circuit, a hand mask (50 ml) and a face chamber having a volume of 850 ml (Siemens-Elema/Sweden). To investigate the dynamic properties of the equipment, we employed flow jumps generated with a magnetic valve (response time < 2 ms) and analysed the responses using Fourier analysis. We were unable to find any significant relationship between the accuracy of volume measurement and tidal volume for any of the measured volumes. An increase in background flow resulted in an underestimation of the volume with an error < 3%. We found no influence of the background flow or type of face mask on the frequency response.(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
D008176	Lung Volume Measurements	Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.	Lung Capacities,Lung Volumes,Capacity, Lung,Lung Capacity,Lung Volume,Lung Volume Measurement,Measurement, Lung Volume,Volume, Lung
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
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
D012123	Pulmonary Ventilation	The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.	Respiratory Airflow,Ventilation Tests,Ventilation, Pulmonary,Expiratory Airflow,Airflow, Expiratory,Airflow, Respiratory,Test, Ventilation,Tests, Ventilation,Ventilation Test
D012126	Respiratory Dead Space	That part of the RESPIRATORY TRACT or the air within the respiratory tract that does not exchange OXYGEN and CARBON DIOXIDE with pulmonary capillary blood.	Dead Space, Respiratory,Dead Spaces, Respiratory,Respiratory Dead Spaces,Space, Respiratory Dead,Spaces, Respiratory Dead
D012127	Respiratory Distress Syndrome, Newborn	A condition of the newborn marked by DYSPNEA with CYANOSIS, heralded by such prodromal signs as dilatation of the alae nasi, expiratory grunt, and retraction of the suprasternal notch or costal margins, mostly frequently occurring in premature infants, children of diabetic mothers, and infants delivered by cesarean section, and sometimes with no apparent predisposing cause.	Infantile Respiratory Distress Syndrome,Neonatal Respiratory Distress Syndrome,Respiratory Distress Syndrome, Infant
D004867	Equipment Design	Methods and patterns of fabricating machines and related hardware.	Design, Equipment,Device Design,Medical Device Design,Design, Medical Device,Designs, Medical Device,Device Design, Medical,Device Designs, Medical,Medical Device Designs,Design, Device,Designs, Device,Designs, Equipment,Device Designs,Equipment Designs
D005583	Fourier Analysis	Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)	Fourier Series,Fourier Transform,Analysis, Cyclic,Analysis, Fourier,Cyclic Analysis,Analyses, Cyclic,Cyclic Analyses,Series, Fourier,Transform, Fourier
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man