scholarly journals Accuracy of noninvasive estimates of respiratory muscle effort during spontaneous breathing in restrictive diseases

2003 ◽  
Vol 95 (4) ◽  
pp. 1542-1549 ◽  
Author(s):  
Francisco García-Río ◽  
José M. Pino ◽  
Angeles Ruiz ◽  
Salvador Díaz ◽  
Concepción Prados ◽  
...  

Mean inspiratory pressure (Pi), estimated from the occlusion pressure at the mouth and the inspiratory time, is useful as a noninvasive estimate of respiratory muscle effort during spontaneous breathing in normal subjects and patients with chronic obstructive pulmonary disease. The aim of this study was to compare the Pi with respect to mean esophageal pressure (Pes) in patients with restrictive disorders. Eleven healthy volunteers, 12 patients with chest wall disease, 14 patients with usual interstitial pneumonia, and 17 patients with neuromuscular diseases were studied. Pi, Pes, and mean transdiaphragmatic pressure were simultaneously measured. Tension-time indexes of diaphragm (TTdi) and inspiratory muscles (TTmu) were also determined. In neuromuscular patients, significant correlations were found between Pi and Pes, Pi and transdiaphragmatic pressure, and TTmu and TTdi. A moderate agreement between Pi and Pes and between TTmu and TTdi was found. No significant correlation between these parameters was found in the other patient groups. These findings suggest that Pi is a good surrogate for the invasive measurement of respiratory muscle effort during spontaneous breathing in neuromuscular patients.

1985 ◽  
Vol 58 (5) ◽  
pp. 1469-1476 ◽  
Author(s):  
D. Laporta ◽  
A. Grassino

Maximal force developed by the diaphragm at functional residual capacity is a useful index to establish muscle weakness; however, great disparity in its reproducibility can be observed among reports in the literature. We evaluated five maneuvers to measure maximal transdiaphragmatic pressure (Pdimax) in order to establish best reproducibility and value. Thirty-five naive subjects, including 10 normal subjects (group 1), 12 patients with chronic obstructive pulmonary disease (group 2), and 13 patients with restrictive pulmonary disease (group 3), were studied. Each subject performed five separate maneuvers in random order that were repeated until reproducible values were obtained. The maneuvers were Mueller with (A) and without mouthpiece (B), abdominal expulsive effort with open glottis (C), two-step (maneuver C combined with Mueller effort) (D), and feedback [two-step with visual feedback of pleural (Ppl) and abdominal (Pab) pressure] (E). The greatest reproducible Pdimax values were obtained with maneuver E (P less than 0.01) (group 1: 180 +/- 14 cmH2O). The second best maneuvers were A, B, and D (group 1: 154 +/- 25 cmH2O). Maneuver C produced the lowest values. For all maneuvers, group 1 produced higher values than groups 2 and 3 (P less than 0.001), which were similar. The Ppl to Pdi ratio was 0.6 in maneuvers A and B, 0.4 in D and E, and 0.2 in C. We conclude that visual feedback of Ppl and Pab helped the subjects to elicit maximal diaphragmatic effort in a reproducible fashion. It is likely that the great variability of values in Pdimax previously reported are the result of inadequate techniques.


1983 ◽  
Vol 55 (1) ◽  
pp. 8-15 ◽  
Author(s):  
F. Bellemare ◽  
A. Grassino

The fatigue threshold of the human diaphragm in normal subjects corresponds to a transdiaphragmatic pressure (Pdi)-inspiratory time integral (TTdi) of about 15% of Pdimax. The TTdi of resting ventilation was measured in 20 patients with chronic obstructive pulmonary disease (COPD) and ranged between 1 and 12% of Pdimax (mean 5%). TTdi was significantly related to total airway resistance (Raw) (r = 0.57; P less than 0.05). Five of these patients were asked to voluntarily modify their TI/TT (ratio of inspiratory time to total cycle duration; from 0.33 to 0.49) so as to increase their TTdi from a control value of 8% to an imposed value of 17% of Pdimax. The imposed pattern induced a progressive decline in the high-frequency (150-350 Hz)/low-frequency (20-40 Hz) power ratio (H/L) of the diaphragm electromyogram (fatigue pattern), quantitatively similar to that seen in normal subjects breathing with similar TTdi levels. The decay in H/L was followed by a progressive fall in mean Pdi meanly due to decrease in gastric pressure swings. It is concluded that 1) the force reserve of the diaphragm in COPD patients is decreased because of a decrease in Pdimax; 2) the remaining force reserve of the diaphragm can be exhausted by even minor modifications in the breathing pattern; and 3) at a TI/TT of 0.40 our COPD patients can increase their mean Pdi 3-fold before reaching a fatiguing pattern of breathing compared with 8-fold in normal subjects.


Thorax ◽  
2001 ◽  
Vol 56 (6) ◽  
pp. 438-444
Author(s):  
P Sivasothy ◽  
L Brown ◽  
I E Smith ◽  
J M Shneerson

BACKGROUNDIt has been suggested that cough effectiveness can be improved by assisted techniques. The effects of manually assisted cough and mechanical insufflation on cough flow physiology are reported in this study.METHODSThe physiological actions and patient self-assessment of manually assisted cough and mechanical insufflation were investigated in 29 subjects (nine normal subjects, eight patients with chronic obstructive pulmonary disease (COPD), four subjects with respiratory muscle weakness (RMW) with scoliosis, and eight subjects with RMW without scoliosis).RESULTSThe peak cough expiratory flow rate and cough expiratory volume were not improved by manually assisted cough and mechanical insufflation alone or in combination in normal subjects. The median increase in peak cough expiratory flow in subjects with RMW without scoliosis with manually assisted cough alone or in combination with mechanical insufflation of 84 l/min (95% confidence interval (CI) 19 to 122) and 144 l/min (95% CI 14 to 195), respectively, reflects improvement in the expulsive phase of coughing by these techniques. Manually assisted cough and mechanical insufflation in combination raised peak expiratory flow rate more than either technique alone in this group. The abnormal chest shape in scoliotic subjects and the fixed inspiratory pressure used made effective manually assisted cough and mechanical insufflation difficult in this group and no improvements were found. In patients with COPD manually assisted cough alone and in combination with mechanical insufflation decreased peak expiratory flow rate by 144 l/min (95% CI 25 to 259) and 135 l/min (95% CI 30 to 312), respectively.CONCLUSIONSManually assisted cough and mechanical insufflation should be considered to assist expectoration of secretions in patients with RMW without scoliosis but not in those with scoliosis.


1995 ◽  
Vol 78 (2) ◽  
pp. 646-653 ◽  
Author(s):  
M. Ramonatxo ◽  
P. Boulard ◽  
C. Prefaut

The aim of this study was to validate a noninvasive tension-time index (TT) for all the inspiratory muscles estimated from the measurement of mouth occlusion pressure (P0.1), i.e., TT of inspiratory muscles (TTmus = PI/PImax x TI/TT, where PI is mean inspiratory pressure, PImax is maximal PI, TI is time of muscle contraction, and TT is total time of respiratory cycle) compared with TT of the diaphragm (TTdi = Pdi/Pdimax x TI/TT, where Pdi is mean transdiaphragmatic pressure and Pdimax is maximal Pdi). PI was estimated as PI = 5 P0.1 x TI. Eleven patients with chronic obstructive pulmonary disease and seven normal subjects were studied at rest in the sitting position. After 5 min of steady state, we measured breathing pattern, gastric and esophageal pressures, Pdi, mean inspiratory transpulmonary pressure swing, PImax, and Pdimax. By linear regression analysis, significant positive correlations were found between PI and mean inspiratory transpulmonary pressure swing, PI and Pdi, PImax and Pdimax, and PI/PImax and Pdi/Pdimax, with P < 0.001 for all subjects combined. These led to the highly significant correlation between TTmus and TTdi for all subjects combined (TTmus = 2.1 TTdi + 0.012; r = 0.97; P < 0.001) and for patients only (TTmus = 2.0 TTdi + 0.024; r = 0.97; P < 0.001). Therefore, patterns of breathing that lie near fatigue thresholds can be identified with TTmus or TTdi. In conclusion, noninvasive and clinically easily determined TTmus seems valid for situating patients of chronic obstructive pulmonary disease in reference to the inspiratory muscle fatigue.


1994 ◽  
Vol 76 (1) ◽  
pp. 39-44 ◽  
Author(s):  
G. Gayan-Ramirez ◽  
F. Palecek ◽  
Y. Chen ◽  
S. Janssens ◽  
M. Decramer

During acute hyperinflation, patients with chronic obstructive pulmonary disease are likely to have foreshortened inspiratory muscles. Because the effects of aminophylline on contractile properties of the foreshortened diaphragm have never been studied in vivo, we compared these effects with those obtained at functional residual capacity (FRC). In 12 anesthetized dogs, bilateral phrenic nerve stimulation (1, 10, 20, and 100 Hz) was performed at FRC and near total lung capacity (TLC) before and 1 h after each injection of aminophylline, given in cumulative doses of 20, 40, and 80 mg/kg (serum levels of 18.7 +/- 6.3, 29.9 +/- 5.9, and 60.4 +/- 11.9 mg/l, respectively). Passive diaphragm shortening from FRC to TLC, measured in eight animals, averaged 30 +/- 12% of the resting length and increased to 35 +/- 12 and 34 +/- 13% after 40 and 80 mg/kg, respectively. After aminophylline, the increase in transdiaphragmatic pressure at FRC did not reach statistical significance, whereas near TLC transdiaphragmatic pressure significantly increased with 80 mg/kg at all stimulus frequencies (e.g., at 20 Hz from 4.4 +/- 2.9 to 6.7 +/- 2.9 cmH2O) and with 40 mg/kg at 10 and 20 Hz. Diaphragm length changes during stimulation were unchanged after aminophylline both at FRC and near TLC. We conclude that aminophylline has a pronounced inotropic effect on foreshortened canine diaphragm, even at concentrations close to the therapeutic range in humans.


1999 ◽  
Vol 87 (3) ◽  
pp. 920-927 ◽  
Author(s):  
Kirby L. Zeman ◽  
Gerhard Scheuch ◽  
Knut Sommerer ◽  
James S. Brown ◽  
William D. Bennett

Effective airway dimensions (EADs) were determined in vivo by aerosol-derived airway morphometry as a function of volumetric lung depth (VLD) to identify and characterize, noninvasively, the caliber of the transitional bronchiole region of the human lung and to compare the EADs by age, gender, and disease. By logarithmically plotting EAD vs. VLD, two distinct regions of the lung emerged that were identified by characteristic line slopes. The intersection of proximal and distal segments was defined as VLDtransand associated EADtrans. In our normal subjects ( n = 20), VLDtrans [345 ± 83 (SD) ml] correlated significantly with anatomic dead space (224 ± 34 ml) and end of phase II of single-breath nitrogen washout (360 ± 53 ml). The corresponding EADtranswas 0.42 ± 0.07 mm, in agreement with other ex vivo measurements of the transitional bronchioles. VLDtrans was smaller (216 ± 64 ml) and EADtrans was larger (0.83 ± 0.04 mm) in our patients with chronic obstructive pulmonary disease ( n = 13). VLDtrans increased with age for children (age 8–18 yr; P = 0.006, n = 26) and with total lung capacity for age 8–81 yr ( P < 0.001, n = 61). This study extends the usefulness of aerosol-derived airway morphometry to in vivo measurements of the transitional bronchioles.


1988 ◽  
Vol 64 (6) ◽  
pp. 2482-2489 ◽  
Author(s):  
P. Leblanc ◽  
E. Summers ◽  
M. D. Inman ◽  
N. L. Jones ◽  
E. J. Campbell ◽  
...  

The capacity of inspiratory muscles to generate esophageal pressure at several lung volumes from functional residual capacity (FRC) to total lung capacity (TLC) and several flow rates from zero to maximal flow was measured in five normal subjects. Static capacity was 126 +/- 14.6 cmH2O at FRC, remained unchanged between 30 and 55% TLC, and decreased to 40 +/- 6.8 cmH2O at TLC. Dynamic capacity declined by a further 5.0 +/- 0.35% from the static pressure at any given lung volume for every liter per second increase in inspiratory flow. The subjects underwent progressive incremental exercise to maximum power and achieved 1,800 +/- 45 kpm/min and maximum O2 uptake of 3,518 +/- 222 ml/min. During exercise peak esophageal pressure increased from 9.4 +/- 1.81 to 38.2 +/- 5.70 cmH2O and end-inspiratory esophageal pressure increased from 7.8 +/- 0.52 to 22.5 +/- 2.03 cmH2O from rest to maximum exercise. Because the estimated capacity available to meet these demands is critically dependent on end-inspiratory lung volume, the changes in lung volume during exercise were measured in three of the subjects using He dilution. End-expiratory volume was 52.3 +/- 2.42% TLC at rest and 38.5 +/- 0.79% TLC at maximum exercise.


2019 ◽  
Vol 7 (01) ◽  
pp. 28
Author(s):  
Nury Nusdwinuringtyas ◽  
Siti Chandra Widjanantie

Introduction: Chronic Obstructive Pulmonary Disease (COPD) was characteristic by the inflammatory process in the airway which causes air trapping and hyperinflation, then followed by decreasing the respiratory muscle strength. Breathing training using the positive expiratory pressure (PEP) increasing respiratory muscle strength.Methods: A case presentation of a male, age was 60 years old diagnosed as COPD by The Global Initiative for Chronic Obstructive Lung Disease (GOLD) grade 4 group D, and Chronic Heart Failure (CHF) grade II, with complication of excessive phlegm, underweight, and weakness of respiratory muscle, have PEP for 8 weeks.Results: Spirometry evaluation before and after eight week of PEP have found; FEV1 22.12 and 22.42%, FVC 34.24 and 56%, FEV1/FVC 76.8 and 64%. Respiratory muscle strength before and after PEP showed the Muscle Inspiratory Pressure (MIP) 46 and 71 cmH2O, Muscle Expiratory Pressure (MEP) 48 and 104 cmH2O.The values of Six Minute Walk Test (6MWT) evaluation by BORG modified scale before and after PEP were 11 and 13 ( efforts), 2 and 3 (dyspnea), 0 and 1 (Leg Fatigue). The six-minute walking distance (6MWD) before and after PED were 170 and 190 m, equation reference with Nury’s formula showed percentage prediction before and after PEP respectively 29.2 and 32%, VO2Max; 4.96 and 6L, METs; 1.41 and 1.7. The St GeorgeRespiratory Questionnaire (SGRQ) before and after PEP were 20.6 and 49.5% (symptom), 86.6 and 45.1% (activity), 45.5 and 18.4% (impact) and 53.6 and 42% for total.Conclusion: Positive airway pressure exercise had beneficial effect on reducing air-trapping process in COPD and increasing the respiratory muscle strength for both expiratory and inspiratory muscle strength.Keywords: Chronic obstructive pulmonary disease, positive expiratory pressure device, respiratory muscle strength, six minutes walking distance


Author(s):  
Winny W ◽  
Siti Chandra Widjanantie ◽  
Maryastuti M ◽  
Nury Nusdwinuringtyas

Background: Chronic Obstructive Pulmonary Disease (COPD) patients experienced respiratory muscledysfunction, postural instability, and decreasing in health status. Abdominal drawing-in maneuver (ADIM) hasbeen studied in many cases of low back pain for lumbar stabilization, moreover this maneuver is also designedto activate the transversus abdominalis (TA) muscle that involved in expiration. But this exercise has not beenconsidered as a respiration exercise in COPD patients. The purpose of this study was to determine whether theapplication of ADIM to COPD patients would affect the strength of respiratory muscle, improve core musclestability, and health status of COPD patients.Methods:All clinically stable COPD patients who visited PMR clinic at Persahabatan General Hospital wererecruited in the study. They received exercise interventions 2 times a week for 4 weeks. ADIM as a mainprogram is using pressure transducer (Chattanooga, Australia). Each exercise was held 10 repetitions, 10 setswith 2 minutes rest. Strength of respiratory muscle measured by peak cough flow (PCF) and peak flow rate(PFR). Core muscle stability measured by functional reach test (FRT) and the health status measured with CATscore. The measurements were done before and immediately after intervention.Results: Subjects were 8 patients with mean age 62 years old, consisted of 7 men and 1 woman, with 1 patienteach with COPD grade A, B, and C, and 5 patients with COPD grade D. There were increasing of PCF (268.75± 59.146 L/min to 285.00 ±59.522 L/min; p=0.061), PFR (251.3±96.3 L/min to 286.3±92 L/min; p=0.028),FRT (20.2±3.8 cm to 22±3.9 cm; p=0.011), and decreasing of CAT score (14 ±8.685 to 11.50 ±8.848; p=0.027)after ADIM.Conclusion: There were an improvement in respiratory muscle, trunk stability, and CAT after ADIM, so themaneuver is effective for COPD management.Keywords: Abdominal drawing-in maneuver (ADIM), Chronic Obstructive Pulmonary Disease (COPD),COPD Assessment Test (CAT), Functional reach test (FRT), Peak cough flow (PCF), Peak flow rate (PFR)


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