Effects of PEEP and tidal volume on elastances and distribution of volume changes of the different chest wall compartments

Allen et al. (J. Clin. Invest. 76: 620–629, 1985) reported that during oscillatory forcing the base of isolated canine lungs distends preferentially relative to the apex as frequency and tidal volume increase. The tendency toward such nonuniform phasic lung distension might influence phasic displacement of the rib cage (RC) relative to the abdomen (ABD). To test this hypothesis we measured RC and ABD displacement in four anesthetized dogs during forced oscillation. Sinusoidal volume changes were delivered through a tracheostomy at 1–32 Hz and measured by body plethysmography. RC and ABD displacements were measured by inductive plethysmography. During oscillation with air at fixed tidal volumes (10–80 ml) RC, normalized to unity at 1 Hz, increased to 2.06–2.22 at 8 Hz (P less than 0.001) and then decreased to 1.06–1.35 (P less than 0.0025) at 32 Hz. ABD, normalized to unity at 1 Hz, was 1.12–1.16 at 4 Hz (P less than 0.001) and decreased to 0.12–0.14 at 32 Hz (P less than 0.001). Displacement of ABD relative to RC did not increase systematically with increasing tidal volume during sinusoidal forcing at any frequency. Thus we found no discernible influence of nonuniform phasic lung distension on chest wall behavior. We infer that in the dog the nonuniform mechanical behavior of the chest wall dominates the nonuniform (but opposing) mechanical tendency of the lung.

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Compartmental chest wall volume changes during volitional hyperpnoea with constant tidal volume in healthy individuals

Respiratory Physiology & Neurobiology ◽

10.1016/j.resp.2012.08.018 ◽

2013 ◽

Vol 185 (2) ◽

pp. 410-415 ◽

Cited By ~ 2

Author(s):

Sabine K. Illi ◽

Stefanie Hostettler ◽

Andrea Aliverti ◽

Christina M. Spengler

Keyword(s):

Tidal Volume ◽

Chest Wall ◽

Healthy Individuals ◽

Volume Changes

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Ventilatory response to hypoxia in unanesthetized newborn kittens

Journal of Applied Physiology ◽

10.1152/jappl.1988.64.6.2544 ◽

1988 ◽

Vol 64 (6) ◽

pp. 2544-2551 ◽

Cited By ~ 15

Author(s):

H. Rigatto ◽

C. Wiebe ◽

C. Rigatto ◽

D. S. Lee ◽

D. Cates

Keyword(s):

Tidal Volume ◽

Chest Wall ◽

Ventilatory Response ◽

Minute Ventilation ◽

Respiratory Frequency ◽

Quiet Sleep ◽

Newborn Kitten ◽

Peripheral Mechanism ◽

Flow Through ◽

Ventilatory Response To Hypoxia

We studied the ventilatory response to hypoxia in 11 unanesthetized newborn kittens (n = 54) between 2 and 36 days of age by use of a flow-through system. During quiet sleep, with a decrease in inspired O2 fraction from 21 to 10%, minute ventilation increased from 0.828 +/- 0.029 to 1.166 +/- 0.047 l.min-1.kg-1 (P less than 0.001) and then decreased to 0.929 +/- 0.043 by 10 min of hypoxia. The late decrease in ventilation during hypoxia was related to a decrease in tidal volume (P less than 0.001). Respiratory frequency increased from 47 +/- 1 to 56 +/- 2 breaths/min, and integrated diaphragmatic activity increased from 14.9 +/- 0.9 to 20.2 +/- 1.4 arbitrary units; both remained elevated during hypoxia (P less than 0.001). Younger kittens (less than 10 days) had a greater decrease in ventilation than older kittens. These results suggest that the late decrease in ventilation during hypoxia in the newborn kitten is not central but is due to a peripheral mechanism located in the lungs or respiratory pump and affecting tidal volume primarily. We speculate that either pulmonary bronchoconstriction or mechanical uncoupling of diaphragm and chest wall may be involved.

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COMPARTMENTAL VOLUME CHANGES AND CHEST WALL MECHANICS AFTER EPIDURAL FENTANYL

Anesthesiology ◽

10.1097/00000542-198609001-00496 ◽

1986 ◽

Vol 65 (Supplement 3A) ◽

pp. A498 ◽

Cited By ~ 2

Author(s):

B. Mankikian ◽

J. F. Brichant ◽

B. Riou ◽

M. A. Delima ◽

R. Sartene ◽

...

Keyword(s):

Chest Wall ◽

Epidural Fentanyl ◽

Volume Changes ◽

Chest Wall Mechanics

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Mechanical impedances of lungs and chest wall in the cat

Journal of Applied Physiology ◽

10.1152/jappl.1992.73.2.427 ◽

1992 ◽

Vol 73 (2) ◽

pp. 427-433 ◽

Cited By ~ 110

Author(s):

Z. Hantos ◽

A. Adamicza ◽

E. Govaerts ◽

B. Daroczy

Keyword(s):

Chest Wall ◽

Respiratory System ◽

Small Volume ◽

Angular Frequency ◽

Forced Oscillations ◽

Amplitude Dependence ◽

Volume Changes ◽

The Real ◽

Output Flow ◽

Frequency Independent

In nine anesthetized and paralyzed cats, the mechanical impedances of the total respiratory system (Zrs) and the lungs (ZL) were measured with small-volume pseudorandom forced oscillations between 0.2 and 20 Hz. ZL was measured after thoracotomy, and chest wall impedance (Zw) was calculated as Zw = Zrs-ZL. All impedances were determined by using input airflow [input impedance (Zi)] and output flow measured with a body box [transfer impedance (Zt)]. The differences between Zi and Zt were small for Zrs and negligible for ZL. At 0.2 Hz, the real and imaginary parts of ZL amounted to 33 +/- 4 and 35 +/- 3% (SD), respectively, of Zrs. Up to 8 Hz, all impedances were consistent with a model containing a frequency-independent resistance and inertance and a constant-phase tissue part (G-jH)/omega alpha, where G and H are coefficients for damping and elastance, respectively, omega is angular frequency, and alpha determines the frequency dependence of the real and imaginary parts. G/H was higher for Zw than for ZL (0.29 +/- 0.05 vs. 0.22 +/- 0.04, P less than 0.01). In four cats, the amplitude dependence of impedances was studied: between oscillation volumes of 0.8 and 3 ml, GL, HL, Gw, and Hw decreased on average by 3, 9, 26, and 29%, respectively, whereas the change in G/H was small for both ZL (7%) and Zw (-4%). The values of H were two to three times higher than the quasistatic elastances estimated with greater volume changes (greater than 20 ml).

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Respiratory impedances and acinar gas transfer in a canine model for emphysema

Journal of Applied Physiology ◽

10.1152/jappl.1997.83.1.179 ◽

1997 ◽

Vol 83 (1) ◽

pp. 179-188 ◽

Cited By ~ 8

Author(s):

George M. Barnas ◽

Paul A. Delaney ◽

Ileana Gheorghiu ◽

Srinivas Mandava ◽

Robert G. Russell ◽

...

Keyword(s):

Tidal Volume ◽

Chest Wall ◽

Canine Model ◽

Gas Transfer ◽

Secondary Complications ◽

Flow Measurements ◽

Mechanically Ventilated ◽

Tissue Sections ◽

Acinar Structure ◽

Blood Flow Measurements

Barnas, George M., Paul A. Delaney, Ileana Gheorghiu, Srinivas Mandava, Robert G. Russell, Renée Kahn, and Colin F. Mackenzie. Respiratory impedances and acinar gas transfer in a canine model for emphysema. J. Appl. Physiol. 83(1): 179–188, 1997.—We examined how the changes in the acini caused by emphysema affected gas transfer out of the acinus (Taci) and lung and chest wall mechanical properties. Measurements were taken from five dogs before and 3 mo after induction of severe bilateral emphysema by exposure to papain aerosol (170–350 mg/dose) for 4 consecutive wk. With the dogs anesthetized, paralyzed, and mechanically ventilated at 0.2 Hz and 20 ml/kg, we measured Taciby the rate of washout of133Xe from an area of the lung with occluded blood flow. Measurements were repeated at positive end-expiratory pressures (PEEP) of 10, 5, 15, 0, and 20 cmH2O. We also measured dynamic elastances and resistances of the lungs (El and Rl, respectively) and chest wall at the different PEEP and during sinusoidal forcing in the normal range of breathing frequency and tidal volume. After final measurements, tissue sections from five randomly selected areas of the lung each showed indications of emphysema. Taciduring emphysema was similar to that in control dogs. Eldecreased by ∼50% during emphysema ( P < 0.05) but did not change its dependence on frequency or tidal volume. Rl did not change ( P > 0.05) at the lowest frequency studied (0.2 Hz), but in some dogs it increased compared with control at the higher frequencies. Chest wall properties were not changed by emphysema ( P > 0.05). We suggest that although large changes in acinar structure and El occur during uncomplicated bilateral emphysema, secondary complications must be present to cause several of the characteristic dysfunctions seen in patients with emphysema.

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Effects of Dexmedetomidine Infusion on Inflammatory Responses and Injury of Lung Tidal Volume Changes during One-Lung Ventilation in Thoracoscopic Surgery: A Randomized Controlled Trial

Mediators of Inflammation ◽

10.1155/2018/2575910 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8 ◽

Cited By ~ 8

Author(s):

Chun-Yu Wu ◽

Yi-Fan Lu ◽

Man-Ling Wang ◽

Jin-Shing Chen ◽

Yen-Chun Hsu ◽

...

Keyword(s):

Tidal Volume ◽

Inflammatory Responses ◽

Thoracoscopic Surgery ◽

Controlled Trial ◽

Lung Ventilation ◽

Saline Group ◽

Medical Complication ◽

Volume Changes ◽

One Lung Ventilation ◽

Monocyte Chemoattractant Protein 1

One-lung ventilation in thoracic surgery provokes profound systemic inflammatory responses and injury related to lung tidal volume changes. We hypothesized that the highly selective a2-adrenergic agonist dexmedetomidine attenuates these injurious responses. Sixty patients were randomly assigned to receive dexmedetomidine or saline during thoracoscopic surgery. There is a trend of less postoperative medical complication including that no patients in the dexmedetomidine group developed postoperative medical complications, whereas four patients in the saline group did (0% versus 13.3%,p=0.1124). Plasma inflammatory and injurious biomarkers between the baseline and after resumption of two-lung ventilation were particularly notable. The plasma high-mobility group box 1 level decreased significantly from 51.7 (58.1) to 33.9 (45.0) ng.ml−1(p<0.05) in the dexmedetomidine group, which was not observed in the saline group. Plasma monocyte chemoattractant protein 1 [151.8 (115.1) to 235.2 (186.9) pg.ml−1,p<0.05] and neutrophil elastase [350.8 (154.5) to 421.9 (106.1) ng.ml−1,p<0.05] increased significantly only in the saline group. In addition, plasma interleukin-6 was higher in the saline group than in the dexmedetomidine group at postoperative day 1 [118.8 (68.8) versus 78.5 (58.8) pg.ml−1,p=0.0271]. We conclude that dexmedetomidine attenuates one-lung ventilation-associated inflammatory and injurious responses by inhibiting alveolar neutrophil recruitment in thoracoscopic surgery.

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Effect of changes in lung volume on respiratory system compliance in newborn infants

Journal of Applied Physiology ◽

10.1152/jappl.1989.67.3.1192 ◽

1989 ◽

Vol 67 (3) ◽

pp. 1192-1197 ◽

Cited By ~ 14

Author(s):

F. Ratjen ◽

R. Zinman ◽

A. R. Stark ◽

L. E. Leszczynski ◽

M. E. Wohl

Keyword(s):

Tidal Volume ◽

Respiratory System ◽

Lung Volume ◽

Newborn Infants ◽

Face Mask ◽

Flow Volume ◽

Respiratory System Compliance ◽

Tidal Breathing ◽

Volume Changes ◽

Passive Flow

Total respiratory system compliance (Crs) at volumes above the tidal volume (VT) was studied by use of the expiratory volume clamping (EVC) technique in 10 healthy sleeping unsedated newborn infants. Flow was measured with a pneumotachograph attached to a face mask and integrated to yield volume. Volume changes were confirmed by respiratory inductance plethysmography. Crs measured by EVC was compared with Crs during tidal breathing determined by the passive flow-volume (PFV) technique. Volume increases of approximately 75% VT were achieved with three to eight inspiratory efforts during expiratory occlusions. Crs above VT was consistently greater than during tidal breathing (P less than 0.0005). This increase in Crs likely reflects recruitment of lung units that are closed or atelectatic in the VT range. Within the VT range, Crs measured by PFV was compared with that obtained by the multiple-occlusion method (MO). PFV yielded greater values of Crs than MO (P less than 0.01). This may be due to braking of expiratory airflow after the release of an occlusion or nonlinearity of Crs. Thus both volume recruitment and airflow retardation may affect the measurement of Crs in unsedated newborn infants.

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Determinants of the esophageal-pleural pressure relationship in humans

Journal of Applied Physiology ◽

10.1152/japplphysiol.00587.2019 ◽

2020 ◽

Vol 128 (1) ◽

pp. 78-86 ◽

Cited By ~ 1

Author(s):

Iacopo Pasticci ◽

Paolo Cadringher ◽

Lorenzo Giosa ◽

Michele Umbrello ◽

Paolo Formenti ◽

...

Keyword(s):

Tidal Volume ◽

Chest Wall ◽

Supine Position ◽

Body Position ◽

Esophageal Pressure ◽

Lateral Position ◽

Pleural Pressure ◽

Absolute Value ◽

Gravitational Forces ◽

Chest Wall Elastance

Esophageal pressure has been suggested as adequate surrogate of the pleural pressure. We investigate after lung surgery the determinants of the esophageal and intrathoracic pressures and their differences. The esophageal pressure (through esophageal balloon) and the intrathoracic/pleural pressure (through the chest tube on the surgery side) were measured after surgery in 28 patients immediately after lobectomy or wedge resection. Measurements were made in the nondependent lateral position (without or with ventilation of the operated lung) and in the supine position. In the lateral position with the nondependent lung, collapsed or ventilated, the differences between esophageal and pleural pressure amounted to 4.4 ± 1.6 and 5.1 ± 1.7 cmH2O. In the supine position, the difference amounted to 7.3 ± 2.8 cmH2O. In the supine position, the estimated compressive forces on the mediastinum were 10.5 ± 3.1 cmH2O and on the iso-gravitational pleural plane 3.2 ± 1.8 cmH2O. A simple model describing the roles of chest, lung, and pneumothorax volume matching on the pleural pressure genesis was developed; modeled pleural pressure = 1.0057 × measured pleural pressure + 0.6592 ( r2 = 0.8). Whatever the position and the ventilator settings, the esophageal pressure changed in a 1:1 ratio with the changes in pleural pressure. Consequently, chest wall elastance (Ecw) measured by intrathoracic (Ecw = ΔPpl/tidal volume) or esophageal pressure (Ecw = ΔPes/tidal volume) was identical in all the positions we tested. We conclude that esophageal and pleural pressures may be largely different depending on body position (gravitational forces) and lung-chest wall volume matching. Their changes, however, are identical. NEW & NOTEWORTHY Esophageal and pleural pressure changes occur at a 1:1 ratio, fully justifying the use of esophageal pressure to compute the chest wall elastance and the changes in pleural pressure and in lung stress. The absolute value of esophageal and pleural pressures may be largely different, depending on the body position (gravitational forces) and the lung-chest wall volume matching. Therefore, the absolute value of esophageal pressure should not be used as a surrogate of pleural pressure.

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Respiratory volume perception through the nose and mouth determined noninvasively

Journal of Applied Physiology ◽

10.1152/jappl.1986.61.2.436 ◽

1986 ◽

Vol 61 (2) ◽

pp. 436-439 ◽

Cited By ~ 3

Author(s):

J. Fox ◽

H. Kreisman ◽

A. Colacone ◽

N. Wolkove

Keyword(s):

Tidal Volume ◽

Magnitude Estimation ◽

Normal Subjects ◽

Mouth Breathing ◽

Just Noticeable Difference ◽

Volume Changes ◽

Respiratory Inductive Plethysmography ◽

Wide Range ◽

Volume Doubling ◽

Volume Perception

The relative importance of the nose vs. the mouth in the perception of respiratory volumes has never been assessed, nor have previous respiratory perception studies been performed noninvasively. Using respiratory inductive plethysmography, we monitored 12 normal subjects noninvasively when breathing either exclusively through the nose or mouth. The sensation of inspired volume mouth breathing was compared with that of nose breathing over a wide range of the inspiratory capacity. The psychophysical techniques of tidal volume duplication, tidal volume doubling, and magnitude estimation were utilized. A just noticeable difference was calculated from the constant error of the tidal volume duplication trials. The exponents for magnitude estimation were 1.06 and 1.07 for nose and mouth breathing, respectively. The other psychophysical techniques also revealed no differences in nose and mouth volume perception. These results suggest that tidal volume changes are perceived equally well through the nose and mouth. Furthermore, the location of the receptors, important in volume perception, is probably at a distal point common to the nose and mouth.

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