TY - JOUR
T1 - Airway resistance estimation by best fit analysis in very premature infants
AU - Thomas, M
AU - Greenough, A
AU - Blowes, R
AU - Rafferty, G F
AU - Calvert, S
AU - Marlow, N
AU - Peacock, J L
AU - Milner, A D
PY - 2002
Y1 - 2002
N2 - Plethysmographic measurement of airway resistance (R-aw) has been determined by single-point analysis, usually at 50% of maximum inspiratory flow (MIF). Computer-assisted (best fit) analysis, however, allows R-aw to be calculated by applying a regression line to any portion of the plethysmograph pressure-flow loop. We determined whether the results of best fit analysis using a computer program, sampling at 200 Hz, were influenced by the portion of the inspiratory loop analysed and if best fit or single-point analysis gave more reproducible results. Twenty infants of median gestational age 26 (range 24-28) weeks, were studied at a median age of 12 (12-14) months corrected for prematurity. R-aw was calculated by best fit analysis between 0 and 33% MIF, 0 and 50% MIF and 0 and 67% MIF and single-point analysis at 50% of MIF. Similar mean R-aw values were obtained by best fit analysis between 0 and 33% MIF (2.79 kPa/(1/s)) and 0 and 50% MIF (3.01 kPa/(1/s)) and single-point analysis at 50% MIF (2.86 kPa/(1/s)), but best fit analysis between 0 and 67% gave higher results (3.60 kPa/(1/s)), p <0.0001, Within the linear portion of the inspiratory loop. the mean intrasubject coefficient of variation was lowest for best fit analysis between 0 and 50% MIF. Best fit computerized analysis between 0 and 50% MIF is recommended as the analysis of choice.
AB - Plethysmographic measurement of airway resistance (R-aw) has been determined by single-point analysis, usually at 50% of maximum inspiratory flow (MIF). Computer-assisted (best fit) analysis, however, allows R-aw to be calculated by applying a regression line to any portion of the plethysmograph pressure-flow loop. We determined whether the results of best fit analysis using a computer program, sampling at 200 Hz, were influenced by the portion of the inspiratory loop analysed and if best fit or single-point analysis gave more reproducible results. Twenty infants of median gestational age 26 (range 24-28) weeks, were studied at a median age of 12 (12-14) months corrected for prematurity. R-aw was calculated by best fit analysis between 0 and 33% MIF, 0 and 50% MIF and 0 and 67% MIF and single-point analysis at 50% of MIF. Similar mean R-aw values were obtained by best fit analysis between 0 and 33% MIF (2.79 kPa/(1/s)) and 0 and 50% MIF (3.01 kPa/(1/s)) and single-point analysis at 50% MIF (2.86 kPa/(1/s)), but best fit analysis between 0 and 67% gave higher results (3.60 kPa/(1/s)), p <0.0001, Within the linear portion of the inspiratory loop. the mean intrasubject coefficient of variation was lowest for best fit analysis between 0 and 50% MIF. Best fit computerized analysis between 0 and 50% MIF is recommended as the analysis of choice.
UR - http://www.scopus.com/inward/record.url?scp=0036001361&partnerID=8YFLogxK
U2 - 10.1088/0967-3334/23/2/304
DO - 10.1088/0967-3334/23/2/304
M3 - Article
VL - 23
SP - 279
EP - 285
JO - Physiological Measurement
JF - Physiological Measurement
IS - 2
ER -