The measurement of total respiratory resistance in pre-school children using a modification of the forced oscillation technique

1978 ◽  
Vol 2 (4) ◽  
pp. 190-193 ◽  
Author(s):  
W. Lenney ◽  
Miss R. E. Richardson
1985 ◽  
Vol 58 (4) ◽  
pp. 1164-1169 ◽  
Author(s):  
K. Sekizawa ◽  
H. Sasaki ◽  
T. Takishima

Laryngeal resistance (Rla) in the postpanting interval (PPRla) was examined in five normal subjects in the control state and with methacholine- and histamine-induced bronchoconstriction. Respiratory resistance (Rrs) was measured by the forced oscillation technique at 10 Hz, and Rla was measured by the low-frequency sound method (Sekizawa, K., C. Shindoh, W. Hida, S. Suzuki, et al. J. Appl. Physiol. 55:591–597, 1983). Inspiratory Rrs (IRrs) was lower than expiratory Rrs (ERrs), and Rrs immediately after panting (PPRrs) was not significantly different from IRrs in the three airway conditions. Rla increased with bronchoconstriction and inspiratory Rla (IRla) was lower than expiratory Rla (ERla). PPRla was lower than IRla (P less than 0.01) by an amount corresponding to the decrease in Rrs in the control airway. However, in constricted airways, PPRla was higher than IRla and about the same as ERla. We suggest that the panting maneuver is suitable for minimizing the effect of laryngeal artifact in the control airway, but in the constricted airway the panting maneuver may fail to cause widening of the laryngeal orifice.


Author(s):  
Pasquale Pio Pompilio ◽  
Delcourt Caroline ◽  
Alessandro Gobbi ◽  
Roberto Perissin ◽  
Raffaele Dellacà ◽  
...  

2015 ◽  
Vol 46 (6) ◽  
pp. 1672-1679 ◽  
Author(s):  
Kathryn A. Ramsey ◽  
Sarath C. Ranganathan ◽  
Catherine L. Gangell ◽  
Lidija Turkovic ◽  
Judy Park ◽  
...  

This study aimed to evaluate the ability of the forced oscillation technique (FOT) to detect underlying lung disease in preschool children with cystic fibrosis (CF) diagnosed following newborn screening.184 children (aged 3–6 years) with CF underwent lung function testing on 422 occasions using the FOT to assess respiratory resistance and reactance at the time of their annual bronchoalveolar lavage collection and chest computed tomography scan. We examined associations between FOT outcomes and the presence and progression of respiratory inflammation, infection and structural lung disease.Children with CF who had pronounced respiratory disease, including free neutrophil elastase activity, infection with pro-inflammatory pathogens and structural lung abnormalities had similar FOT outcomes to those children without detectable lung disease. In addition, the progression of lung disease over 1 year was not associated with worsening FOT outcomes.We conclude that the forced oscillation technique is relatively insensitive to detect underlying lung disease in preschool children with CF. However, FOT may still be of value in improving our understanding of the physiological changes associated with early CF lung disease.


1986 ◽  
Vol 71 (s15) ◽  
pp. 8P-9P
Author(s):  
J.E. Neild ◽  
C.H.C. Twort ◽  
S. Chinn ◽  
S. McCormack ◽  
P.G.J. Burney ◽  
...  

1996 ◽  
Vol 80 (4) ◽  
pp. 1105-1111 ◽  
Author(s):  
L. Beydon ◽  
P. Malassine ◽  
A. M. Lorino ◽  
C. Mariette ◽  
F. Bonnet ◽  
...  

Measurement of respiratory impedance by the forced oscillation technique (FOT) in intubated patients requires corrections for the flow-dependent resistance, inertance, and air compression inside the endotracheal tube (ETT). Recently, we published a method to correct respiratory impedance for the mechanical contribution of the ETT. To validate this correction, we compared the respiratory resistance obtained with this method (Rfo) to the intrinsic (Rmin) and total resistances (RT) measured by the airway-occlusion technique (OCT) in 16 intubated sedated paralyzed ventilated patients. The FOT was applied at functional residual capacity in the 4- to 32-Hz frequency range, whereas the OCT was performed at the end of a normal constant-flow inspiration. Rmin corrected with Rfo measured at 16 and 32 Hz [Rfo(16) = 1.10 x Rmin + 0.10 cmH2O.s.l-1, r = 0.96, P < 0.001; Rfo(32) = 0.93 x Rmin + 0.72 cmH2O.s.l-1, r = 0.97, P < 0.001]. RT corrected with Rfo at 4 Hz [Rfo(4) = 1.11 x RT - 1.48 cmH2O.s.l-1; = 0.92; P < 0.001]. We conclude that the FOT improved by correction for the behavior of the ETT is in good agreement with the OCT in intubated patients.


1975 ◽  
Vol 39 (2) ◽  
pp. 305-311 ◽  
Author(s):  
D. C. Stanescu ◽  
R. Fesler ◽  
C. Veriter ◽  
A. Fans ◽  
L. Brasseur

We have modified the measurements of the resistance of the respiratory system, Rrs, by the forced oscillation technique and we have developed equipment to automatically compute Rrs. Flow rate and mouth pressure are treated by selective averaging filters that remove the interference of the subject's respiratory flow on the imposed oscillations. The filtered mean Rrs represents a weighted ensemble average computer over both inspiration and expiration. This method avoids aberrant Rrs values, decreases the variability, and yields an unbiased mean Rrs. Rrs may be measured during slow or rapid spontaneous breathing, in normals and in obstructive patients, over a range of 3–9 Hz. A good reproducibility of Rrs at several days' interval was demonstrated. Frequency dependence of Rrs was found in patients with obstructive lung disease but not in healthy nonsmokers.


1989 ◽  
Vol 83 (2) ◽  
pp. 111-118 ◽  
Author(s):  
J.E. Neild ◽  
C.H.C. Twort ◽  
S. Chinn ◽  
S. McCormack ◽  
T.D. Jones ◽  
...  

1977 ◽  
Vol 42 (4) ◽  
pp. 650-655 ◽  
Author(s):  
H. Aronsson ◽  
L. Solymar ◽  
J. Dempsey ◽  
J. Bjure ◽  
T. Olsson ◽  
...  

We present a modification of forced oscillation technique for automated determination of total respiratory resistance during inspiration. The modifications consist of a computerized signal averaging and an optimization technique in the assessment of the resistance value. Thereby a favorable signal-to-noise ratio is obtained, allowing very low superimposed pressure oscillations. The method is validated by comparison with a conventional esophageal balloon method, by estimating added mechanical resistances in healthy subjects and by measuring the effect of bronchodilation in asthmatic children. The coefficient of variation as obtained from day-to-day measurements was about 7%. Mechanical resistances, estimated as the difference in total resistance with and without external resistance, were within 7% of their values determined for the resistances alone. A significant decrease in resistance was obtained in each of the asthmatic children following bronchodilation.


1992 ◽  
Vol 72 (1) ◽  
pp. 46-52 ◽  
Author(s):  
J. H. Bates ◽  
B. Daroczy ◽  
Z. Hantos

We compared the values of resistance produced by the forced oscillation technique (FOT) and the flow interruption technique (IT) when applied to six anesthetized paralyzed tracheostomized dogs. The FOT returned values of respiratory system resistance as a function of frequency [Re(f)] between 0.25 and 20 Hz. The IT returned a single value of resistance (Rinit) calculated by dividing the immediate change in tracheal pressure occurring upon interruption by the preinterruption flow. We found Rinit to coincide closely with Re(f) in the frequency range 5–20 Hz. Rinit has previously been interpreted as the high-frequency resistance of a resistance-elastance model of the respiratory system airways and tissues. It has also been shown previously, by direct measurement of alveolar pressure in dogs, that Rinit from the lungs alone is an accurate measure of airways resistance while Rinit obtained from the total respiratory system equals airways resistance plus a modest contribution from the chest wall. Re(f) at a frequency of approximately 10 Hz thus appears to be a useful quantity to measure as an index of airways resistance in the dog.


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