Respiratory resistance by end-inspiratory occlusion and forced oscillations in intubated patients

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.

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Correlation between the changes respiratory resistance and reactance assessments, measured by forced oscillation technique (MostGraph), and respiratory-function assessments in childhood asthma

Nihon Shoni Arerugi Gakkaishi The Japanese Journal of Pediatric Allergy and Clinical Immunology ◽

10.3388/jspaci.28.111 ◽

2014 ◽

Vol 28 (1) ◽

pp. 111-118

Author(s):

Atsushi Isozaki ◽

Shingo Kobari ◽

Aki Tanaka ◽

Eriko Ando ◽

Yoichi Nakamura

Keyword(s):

Childhood Asthma ◽

Respiratory Function ◽

Forced Oscillation ◽

Forced Oscillation Technique ◽

Respiratory Resistance

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Perioperative evaluation of respiratory impedance using the forced oscillation technique: a prospective observational study

BMC Anesthesiology ◽

10.1186/s12871-016-0197-y ◽

2015 ◽

Vol 16 (1) ◽

Cited By ~ 5

Author(s):

Shoko Nakano ◽

Junko Nakahira ◽

Toshiyuki Sawai ◽

Yosuke Kuzukawa ◽

Junichi Ishio ◽

...

Keyword(s):

Observational Study ◽

Prospective Observational Study ◽

Forced Oscillation ◽

Forced Oscillation Technique ◽

Respiratory Impedance

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Respiratory parameter estimation using forced oscillatory impedance data

Journal of Applied Physiology ◽

10.1152/jappl.1977.43.2.322 ◽

1977 ◽

Vol 43 (2) ◽

pp. 322-330 ◽

Cited By ~ 22

Author(s):

M. J. Tsai ◽

R. L. Pimmel ◽

E. J. Stiff ◽

P. A. Bromberg ◽

R. L. Hamlin

Keyword(s):

Respiratory Symptoms ◽

Forced Oscillation ◽

Respiratory Resistance ◽

Added Resistance ◽

Tidal Breathing ◽

Frequency Dependency ◽

Respiratory Parameter ◽

Clinically Normal ◽

Impedance Data ◽

Residual Capacity

The frequency dependency of the magnitude and phase angle of total respiratory impedance was measured in apneic dogs at functional residual capacity during forced oscillation by a special electronics unit. Regression analysis of these data yielded estimates of total respiratory resistance (RFO), inertance (IFO), and compliance (CFO). After correcting for the effects of the endotracheal tube, mean control values (+/-SE) of RFO, IFO, and CFO for the clinically normal dogs were 1.30+/-0.10 cmH2O–1–1-s, 0.0114+/-0.0022 cmH2O–1–1-s2, and 0.0306+/-0.0009 1-cm H2O–1, respectively. Estimates obtained with added resistance, a less dense gas, and abdominal weighting were consistent with predicted effects. In four dogs with mild respiratory symptoms, mean RFO was significantly elevated with no change in IFO or CFO. Independent measurements of resistance and compliance during tidal ventilation correlated well with RFO (r=0.87) and CFO (r=0.80), but RFO and CFO were, on the average, 71% of the tidal breathing values. Thus, the method provides precise estimates of RFO, IFO, and CFO, and allows detection of small changes in these parameters.

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Laryngeal resistance immediately after panting in control and constricted airways

Journal of Applied Physiology ◽

10.1152/jappl.1985.58.4.1164 ◽

1985 ◽

Vol 58 (4) ◽

pp. 1164-1169 ◽

Cited By ~ 4

Author(s):

K. Sekizawa ◽

H. Sasaki ◽

T. Takishima

Keyword(s):

Forced Oscillation ◽

Low Frequency ◽

Normal Subjects ◽

Forced Oscillation Technique ◽

Respiratory Resistance ◽

Frequency Sound ◽

Laryngeal Resistance ◽

Control State

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.

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Reference values for respiratory impedance measured by the forced oscillation technique in adult men and women

The Clinical Respiratory Journal ◽

10.1111/crj.12783 ◽

2018 ◽

Vol 12 (6) ◽

pp. 2126-2135 ◽

Cited By ~ 3

Author(s):

Fernando Carlos Vetromille Ribeiro ◽

Agnaldo José Lopes ◽

Pedro Lopes de Melo

Keyword(s):

Reference Values ◽

Forced Oscillation ◽

Forced Oscillation Technique ◽

Respiratory Impedance ◽

Men And Women ◽

Adult Men

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Measurement of total respiratory impedance in calves by the forced oscillation technique

Journal of Applied Physiology ◽

10.1152/jappl.1988.64.5.1786 ◽

1988 ◽

Vol 64 (5) ◽

pp. 1786-1791 ◽

Cited By ~ 26

Author(s):

P. Gustin ◽

A. R. Dhem ◽

F. Lomba ◽

P. Lekeux ◽

K. P. Van de Woestijne ◽

...

Keyword(s):

Resonant Frequency ◽

Fourier Analysis ◽

Respiratory System ◽

Pressure Wave ◽

Forced Oscillation ◽

Forced Oscillation Technique ◽

Respiratory Impedance ◽

Upper Airways ◽

Low Frequencies ◽

Spontaneously Breathing

We have determined the resistance (Rrs) and the reactance (Xrs) of the total respiratory system in unsedated spontaneously breathing calves at various frequencies. A pseudorandom noise pressure wave was produced at the nostrils of the animals by means of a loudspeaker adapted to the nose by a tightly fitting mask. A Fourier analysis of the pressure in the nostrils and flow signals yielded mean Rrs and Xrs, over 16 s, at frequencies of 2–26 Hz. A good correlation was found between values of pulmonary resistances measured by the isovolume method at the respiratory frequency of animals and values obtained at a frequency of 6 Hz by use of our technique. The linearity of the respiratory system, the reproducibility of the technique, and the effects of upper airways on results have been studied. In healthy calves, Rrs increases with frequency. Mean resonant frequency is 7.5 Hz. Bronchospasm was induced in six calves by administration of intravenous organophosphates. Rrs tended to decrease with increasing frequency. Resonant frequency exceeded 26 Hz. All parameters returned to initial values after administration of atropine. In healthy calves, atropine produces a decrease in Rrs, especially at low frequencies. Values of resonant frequency are not modified.

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Impact of lung disease on respiratory impedance in young children with cystic fibrosis

European Respiratory Journal ◽

10.1183/13993003.00156-2015 ◽

2015 ◽

Vol 46 (6) ◽

pp. 1672-1679 ◽

Cited By ~ 12

Author(s):

Kathryn A. Ramsey ◽

Sarath C. Ranganathan ◽

Catherine L. Gangell ◽

Lidija Turkovic ◽

Judy Park ◽

...

Keyword(s):

Cystic Fibrosis ◽

Preschool Children ◽

Lung Disease ◽

Forced Oscillation ◽

Forced Oscillation Technique ◽

Respiratory Resistance ◽

Lung Abnormalities ◽

Respiratory Inflammation ◽

Function Testing ◽

Tomography Scan

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.

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