Differentiation between the intensity of breathlessness and the distress it evokes in normal subjects during exercise

1991 ◽  
Vol 80 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Rachel C. Wilson ◽  
P. W. Jones
Keyword(s):  
Minute Ventilation ◽  
Normal Subjects ◽  
Cycle Ergometer ◽  
Exercise Tests ◽  
Distress Score ◽  
Significant Difference ◽  
Ergometer Exercise ◽  
Wide Scatter ◽  
The Subject ◽  
The Mean

1. This study was designed to examine whether normal subjects could differentiate between the ‘intensity’ of their breathlessness and the amount of ‘distress’ it evoked, by specific wording of the instructions. 2. A preliminary study showed no significant difference between ‘distress’ score during exercise measured on two separate occasions (P = 0.3). 3. Ten subjects each performed two identical incremental cycle-ergometer exercise tests on separate occasions during which they were asked to quantify either ‘intensity’ or ‘distress’ by using modified Borg scales. 4. In all subjects there was a significant correlation (P <0.001) between ‘intensity’ and minute ventilation. In eight subjects there was a significant correlation (P <0.05) between ‘distress’ and minute ventilation. One subject displayed no significant correlation and one registered no distress. 5. Mean ‘intensity’ was greater than the mean ‘distress’ (P = 0.0001). The slope of ‘intensity’/minute ventilation was greater than the slope of ‘distress’/minute ventilation (P = 0.0001). 6. Within individuals there was a significant correlation beween ‘intensity’ and ‘distress’ (P <0.05). There was a wide scatter in the slope of this relationship between subjects and maximum ‘intensity’ and ‘distress’ did not correlate. 7. Different elements of the breathlessness sensation could be identified and selectively measured depending on the wording of the instructions given to the subject. 8. There was a wide intersubject variation in the magnitude of both breathlessness ‘intensity’ and ‘distress’ estimates, but the differences between subjects in these two components of the sensation did not appear to follow a common pattern.

Long-term reproducibility of Borg scale estimates of breathlessness during exercise

1991 ◽  
Vol 80 (4) ◽  
pp. 309-312 ◽  
Author(s):  
Rachel C. Wilson ◽  
P. W. Jones
Keyword(s):  
Minute Ventilation ◽  
Normal Subjects ◽  
Work Rate ◽  
Borg Scale ◽  
Exercise Tests ◽  
Reliable Technique ◽  
Significant Difference ◽  
The Mean ◽  
The Relationship

1. The intensity of breathlessness in normal subjects during exercise was measured on seven occasions over a 40-week study period to assess the long-term repeatability of Borg scale estimates of breathlessness. 2. In all subjects there was a significant correlation (P = 0.0001) between breathlessness and minute ventilation. Minute ventilation measured at each work rate did not differ between the seven exercise tests (P >0.05). 3. There was no significant difference between the mean Borg scores (measured with respect to a given level of ventilation) in 5 of the 7 test weeks (P >0.05). The slope of the relationship Borg score/minute ventilation did not differ between the seven exercise tests (P >0.05). 4. Breathlessness estimation was highly reproducible both after 1 week and after 40 weeks of the study (both P >0.05). 5. The duration without testing between consecutive tests did not affect reproducibility: the mean Borg score was as equally reproducible after an interval of 22 weeks without testing as after an interval of 1 week (P >0.05). 6. The Borg scale provides a reliable technique for studying the sensation of breathlessness over extended time periods.

Factors contributing to increased muscle fatigue with β-blockers

1991 ◽  
Vol 69 (2) ◽  
pp. 254-261 ◽  
Author(s):  
R. S. McKelvie ◽  
N. L. Jones ◽  
G. I. F. Heigenhauser
Keyword(s):  
Muscle Fatigue ◽  
Exercise Performance ◽  
Cycle Ergometer ◽  
Metabolic Effects ◽  
High Dose ◽  
Exercise Tests ◽  
Significant Difference ◽  
Ergometer Exercise ◽  
The Relationship ◽  
Male Subjects

β-Adrenoceptor blockers are widely used clinically and can be classified as nonselective (β1 and β2) or selective (β1). Impairment of exercise performance is a well-known side effect of this group of drugs. This paper reviews mechanisms that could potentially be responsible for this impairment. In addition to cardiovascular and metabolic effects, β -blockade inhibits Na+–K+ ATPase pumps controlling ion movement between muscle and plasma and thus may contribute to muscle fatigue through this mechanism. To investigate the relationship between the change in plasma [K+] and exercise performance, we studied healthy male subjects taking propranolol. Eight subjects performed maximal incremental cycle ergometer exercise tests during control (no drug), low dose (LD) (40 mg daily), and high dose (HD) (265 ± 4.3 (SE) mg daily) of propranolol. The control plasma [K+] (5.8 ± 0.12 mequiv./L) during exercise was significantly lower than either the LD (6.4 ± 0.05 mequiv./L) or HD (6.1 ± 0.16 mequiv./L) values. There was no significant difference between plasma [K+] for the LD and HD of propranolol. However, maximum oxygen uptake was reduced only while taking the HD of propranolol. Six of the subjects also performed three 30-s bouts of high intensity exercise on an isokinetic cycle ergometer while taking the LD and HD of propranolol. There was no significant difference between doses for the increase in plasma [K+] (LD, 7.8 ± 0.35 mequiv./L vs. HD, 7.6 ± 0.36 mequiv./L) during exercise. However, exercise performance was significantly reduced during HD compared with LD. These results suggest that the increases in plasma [K+] with propranolol did not play a direct significant role in the reduced performance observed during the HD.Key words: exercise, potassium, performance, lactate.

A comparison of the visual analogue scale and modified Borg scale for the measurement of dyspnoea during exercise

1989 ◽  
Vol 76 (3) ◽  
pp. 277-282 ◽  
Author(s):  
Rachel C. Wilson ◽  
P. W. Jones
Keyword(s):  
Visual Analogue Scale ◽  
Analogue Scale ◽  
Minute Ventilation ◽  
Normal Subjects ◽  
Work Rate ◽  
Borg Scale ◽  
Exercise Tests ◽  
Vas Score ◽  
The Mean ◽  
The Relationship

1. The intensity of breathlessness during exercise was measured in ten normal subjects using a visual analogue scale (VAS) and a Borg scale to compare the use of the scales and their repeatability, both within the duration of a period of exercise and between tests. For each scale, subjects performed two exercise tests separated by a period of 2–6 weeks. Each exercise test consisted of two cycles of progressively increasing and decreasing workload. 2. All subjects felt confidently able to use both scales to quantify their feelings of breathlessness exclusively of other sensation. Equal preference was expressed for use of a particular scale. 3. With both scales there was a large intersubject variation in the relationship between dyspnoea score and minute ventilation (VE) (P < 0.01), and in the range of the scale used. 4. There was a good correlation between the VAS and Borg scores at each level of VE (r2 = 0.71), but the VAS score was used over a wider range than the Borg score. 5. The relationship between VE and the dyspnoea score measured by the two techniques was predominantly linear. The mean r2 for VAS score/VE was 0.68 (sd 0.19) and for Borg score/VE the mean r2 was 0.75 (sd 0.13). 6. The relationships VAS score/VE and Borg score/VE were unaffected by the direction in which the workload was varied (P > 0.05). 7. VE, measured at each work rate, did not differ between the two cycles (P > 0.05) or between the 2 days (P > 0.05). 8. With both scales, the slope of the VE-breathlessness relationship was slightly higher during the second half of the exercise compared with the first (0.05 < P > 0.01). 9. The scores with both scales were lower in the second test compared with the first (P < 0.01): Borg 16% lower, VAS 27% lower. 10. Measurements of dyspnoea made with the Borg scale appeared to have greater stability than VAS measurements and to correlate with VE a little better.

Effects of nasal cold receptors on pattern of breathing

1988 ◽  
Vol 64 (1) ◽  
pp. 371-376 ◽  
Author(s):  
K. R. Burgess ◽  
W. A. Whitelaw
Keyword(s):  
Minute Ventilation ◽  
Normal Subjects ◽  
Separate Experiment ◽  
Normal Male ◽  
Gas Temperature ◽  
Cold Air ◽  
Significant Difference ◽  
The Mean ◽  
End Tidal ◽  
High Level

To investigate the effect on the pattern of breathing of cooling receptors in the nose, eight normal male volunteers underwent a steady-state CO2 stimulation by nasal inhalation. The inhaled gas temperature was randomly switched between "warm" (32 degrees C) and "cold" (2 degrees C) at each of three levels of inspired CO2 fraction (FICO2). Breathing cold air through the nose reduced the mean slope of the ventilatory response to CO2 by 27% (P less than 0.05) and the mean intercept at PCO2 of 45 Torr by 6.6 l/min (P less than 0.01). This was due mainly to a reduction in tidal volume (VT). Analysis of the breathing pattern recorded at a high level of minute ventilation (VE) (end-tidal partial pressure of CO2 approximately 52 Torr) showed a reduction of VE that was due almost entirely to a reduction in VT (P less than 0.05) associated with a reduction in inspiratory time (TI) as a fraction of total respiratory cycle time (P less than 0.05) but little change in VT/TI. In a separate experiment conducted with five subjects, there was no significant difference in inspired nasal resistance between warm and cold runs during CO2-stimulated breathing. The results confirm the previous observation that cold air breathed through the nose inhibits ventilation in normal subjects and show that this is not related to an increase in flow resistance. The reduction in ventilation is due to reduction in VT associated with shortening of the duty cycle.

Acid-base regulation during exercise and recovery in humans

1992 ◽  
Vol 72 (3) ◽  
pp. 954-961 ◽  
Author(s):  
W. Stringer ◽  
R. Casaburi ◽  
K. Wasserman
Keyword(s):  
Respiratory Acidosis ◽  
Normal Subjects ◽  
Cycle Ergometer ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Exercise Tests ◽  
Cycle Ergometer Exercise ◽  
Arterial Ph ◽  
Ergometer Exercise ◽  
Exercise In Humans

Arterial pH, PCO2, standard bicarbonate, lactate, and ventilation were measured with a high sampling density during rest, exercise, and recovery in normal subjects performing upright cycle ergometer exercise. Three 6-min constant-work exercise tests (moderate, heavy, and very heavy) were performed by each subject. We found a small respiratory acidosis during the moderate-intensity exercise and an early respiratory acidosis followed by a metabolic acidosis for the heavy- and very-heavy-intensity exercise. During recovery, arterial pH rapidly returned to the preexercise value for the moderate-intensity work. However, arterial pH decreased further during the first 2 min of recovery for the heavy- and very-heavy-intensity work, before a slower return toward the resting values. We conclude that arterial acidosis is the consistent arterial pH reaction for moderate-, heavy-, and very-heavy-intensity cycle ergometer exercise in humans and that this acidosis is blunted but not eliminated by the ventilatory response. During recovery, the return to resting arterial pH and PCO2 and standard bicarbonate appears to be determined by the rate of lactate decline.

Mediation of reduced ventilatory response to exercise after endurance training

1987 ◽  
Vol 63 (4) ◽  
pp. 1533-1538 ◽  
Author(s):  
R. Casaburi ◽  
T. W. Storer ◽  
K. Wasserman
Keyword(s):  
Endurance Training ◽  
Venous Blood ◽  
Normal Subjects ◽  
Cycle Ergometer ◽  
Work Rate ◽  
Exercise Tests ◽  
Average Decrease ◽  
Cycle Ergometer Exercise ◽  
Ergometer Exercise ◽  
The Difference

To investigate the mechanism by which ventilatory (VE) demand is modulated by endurance training, 10 normal subjects performed cycle ergometer exercise of 15 min duration at each of four constant work rates. These work rates represented 90% of the anaerobic threshold (AT) work rate and 25, 50, and 75% of the difference between maximum O2 consumption and AT work rates for that subject (as determined from previous incremental exercise tests). Subjects then underwent 8 wk of strenuous cycle ergometer exercise for 45 min/day. They then repeated the four constant work rate tests at work rates identical to those used before training. During tests before and after training, VE and gas exchange were measured breath by breath and rectal temperature (Tre) was measured continuously. A venous blood sample was drawn at the end of each test and assayed for lactate (La), epinephrine (EPI), and norepinephrine (NE). We found that the VE for below AT work was reduced minimally by training (averaging 3 l/min). For the above AT tests, however, training reduced VE markedly, by an average of 7, 23, and 37 l/min for progressively higher work rates. End-exercise La, NE, EPI, and Tre were all lower for identical work rates after training. Importantly, the magnitude of the reduction in VE was well correlated with the reduction in end-exercise La (r = 0.69) with an average decrease of 5.8 l/min of VE per milliequivalent per liter decrease in La. Correlations of VE with NE, EPI, and Tre were much less strong (r = 0.49, 0.43, and 0.15, respectively).

A COMPARISON OF TWO METHODS FOR MEASUREMENT OF ALDOSTERONE SECRETION RATE IN MAN

1966 ◽  
Vol 53 (2) ◽  
pp. 177-188 ◽  
Author(s):  
P. Lund-Johansen ◽  
T. Thorsen ◽  
K. F. Støa
Keyword(s):  
Urinary Excretion ◽  
Normal Subjects ◽  
Secretion Rate ◽  
Aldosterone Secretion ◽  
Simple Method ◽  
Mean Values ◽  
Pathological Conditions ◽  
Significant Difference ◽  
Derivative Method ◽  
The Mean

ABSTRACT A comparison has been made between (A), a relatively simple method for the measurement of aldosterone secretion rate, based on paper chromatography and direct densitometry of the aldosterone spot and (B) a more elaborate isotope derivative method. The mean secretion rate in 9 normal subjects was 112 ± 26 μg per 24 hours (method A) and 135 ± 35 μg per 24 hours (method B). The »secretion rate« in one adrenalectomized subject after the intravenous injection of 250 μg of aldosterone was 230 μg per 24 hours (method A) and 294 μg per 24 hours (method B). There was no significant difference in the mean values, and correlation between the two methods was good (r = 0.80). It is concluded that the densitometric method is suitable for clinical purposes as well as research, being more rapid and less expensive than the isotope derivative method. Method A also measures the urinary excretion of the aldosterone 3-oxo-conjugate, which is of interest in many pathological conditions. The densitometric method is obviously the less sensitive and a prerequisite for its use is an aldosterone secretion of 20—30 μg per 24 hours. Lower values are, however, rare in adults.

Influence of prior ventilatory experience on the estimation of breathlessness during exercise

1990 ◽  
Vol 78 (2) ◽  
pp. 149-153 ◽  
Author(s):  
Rachel C. Wilson ◽  
P. W. Jones
Keyword(s):  
Exercise Test ◽  
Prior Experience ◽  
Minute Ventilation ◽  
Normal Subjects ◽  
Resistive Load ◽  
Inspiratory Time ◽  
Borg Scale ◽  
Exercise Tests ◽  
Loaded Breathing ◽  
Inspiratory Load

1. The intensity of breathlessness was measured during exercise in nine normal subjects using a modified Borg scale to examine the effect of prior experience of breathlessness on subsequent estimates of breathlessness. 2. Each subject performed four exercise tests, each of which consisted of two identical runs of workload incrementation (run 1 and run 2). An inspiratory resistive load of 3.8 cmH2O s−1 l−1 was applied during the appropriate run of the exercise test to examine the effect of (a) prior experience of ‘loaded’ breathing on breathlessness estimation during ‘unloaded’ breathing, and (b) prior experience of ‘unloaded’ breathing on breathlessness estimation during ‘loaded’ breathing. Run 1 was the conditioning run; run 2 was the run in which the effect of conditioning was measured. 3. There was a good correlation between breathlessness and minute ventilation during both unloaded’ breathing (median r = 0.93) and ‘loaded’ breathing (median r = 0.95). 4. The slope of the Borg score/minute ventilation relationship was greater during ‘loaded’ breathing than during ‘unloaded’ breathing (P < 0.01). There was no difference in mean Borg score between ‘unloaded’ and ‘loaded’ breathing. 5. After a period of ‘loaded’ breathing during run 1, estimated breathlessness was significantly reduced during ensuing ‘unloaded’ breathing in run 2 (P < 0.01) compared with the exercise test in which ‘unloaded’ breathing was experienced throughout both run 1 and run 2. 6. After a period of ‘unloaded’ breathing in run 1, estimated breathlessness was significantly increased during ensuing ‘loaded’ breathing in run 2 (P < 0.01) compared with the exercise test in which the inspiratory load had already been experienced in run 1. 7. Changes in the pattern of breathing (inspiratory time, expiratory time, total breath duration, inspiration time/total breath duration ratio and tidal volume) were not consistent with the changes in breathlessness. 8. We suggest that perception of breathlessness may be influenced by a subject's immediate prior experience of an altered relationship between breathlessness and ventilation.

scholarly journals Metabolic, Cardiac, and Hemorheological Responses to Submaximal Exercise under Light and Moderate Hypobaric Hypoxia in Healthy Men

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 144
Author(s):  
Hun-Young Park ◽  
Jeong-Weon Kim ◽  
Sang-Seok Nam
Keyword(s):  
Oxygen Uptake ◽  
Blood Lactate ◽  
Minute Ventilation ◽  
Random Order ◽  
Cycle Ergometer ◽  
Submaximal Exercise ◽  
Erythrocyte Deformability ◽  
Moderate Hypoxia ◽  
Healthy Men ◽  
Significant Difference

We compared the effects of metabolic, cardiac, and hemorheological responses to submaximal exercise under light hypoxia (LH) and moderate hypoxia (MH) versus normoxia (N). Ten healthy men (aged 21.3 ± 1.0 years) completed 30 min submaximal exercise corresponding to 60% maximal oxygen uptake at normoxia on a cycle ergometer under normoxia (760 mmHg), light hypoxia (596 mmHg, simulated 2000 m altitude), and moderate hypoxia (526 mmHg, simulated 3000 m altitude) after a 30 min exposure in the respective environments on different days, in a random order. Metabolic parameters (oxygen saturation (SPO2), minute ventilation, oxygen uptake, carbon dioxide excretion, respiratory exchange ratio, and blood lactate), cardiac function (heart rate (HR), stroke volume, cardiac output, and ejection fraction), and hemorheological properties (erythrocyte deformability and aggregation) were measured at rest and 5, 10, 15, and 30 min after exercise. SPO2 significantly reduced as hypoxia became more severe (MH > LH > N), and blood lactate was significantly higher in the MH than in the LH and N groups. HR significantly increased in the MH and LH groups compared to the N group. There was no significant difference in hemorheological properties, including erythrocyte deformability and aggregation. Thus, submaximal exercise under light/moderate hypoxia induced greater metabolic and cardiac responses but did not affect hemorheological properties.

scholarly journals Diagnostic Significance of Haemogram Parameters and RBC Indices in Haemoglobin E Trait

2017 ◽  
Vol 8 (2) ◽  
pp. 94-99
Author(s):  
Tarannum Khondaker ◽  
Abul Kashem Jalaluddin Ahmed ◽  
Syed Khairul Amin
Keyword(s):  
Blood Count ◽  
Normal Subjects ◽  
Diagnostic Significance ◽  
Group Iii ◽  
Group I ◽  
Significant Difference ◽  
Hb E ◽  
Rbc Indices ◽  
Mean Corpuscular Haemoglobin ◽  
The Mean

Background: Hemoglobin E disease are the most common structural haemoglobinopathies, reaching its highest frequency in South East Asia and also prevalent in Bangladesh. There are very few data for effective screening of HB E trait. The aim of the study was to analyze hematological profile and RBC indices as a marker of screening for Hb E trait.Methodology: A cross sectional observational study was conducted among 150 subjects at Dhaka Shishu (Children) Hospital from December 2008 to November 2009. On the basis of Hb electrophoresis, all subjects were divided into three groups. Group I comprised of 50 subjects with Hb E trait, group II comprised 51 subjects with ß thalassemia trait and Group III comprised of 49 normal subjects. Result of RBC indices and blood count were compared between Hb E trait and normal study population.Results: In group I the mean age was 29.53 years and the age range was 2-47 years. In group II the mean age was 30.31 years and the range was 1-55 years. In group III the mean age was 21.81 years and the range was 1-52 years. The present study revealed the mean±SD haemoglobin level (g/dl) in group I (E trait) and group III (normal subjects) were 11.76±1.91 and 10.77±1.4 respectively. Statistically no significant difference was found between these 2 groups (P>.05). The mean corpuscular volume (MCV) in mean±SD in group I and group III were 72.89±12.24 fl and 77.35±10.27 fl respectively. No statistical significance was found as P>0.05. The mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) in group I were 24.84±2.71pg & 32.97±2.27 g/dl and in group III were 28.28±2.71 pg & 32.97±2.38 g/dl respectively. There were no significant difference between group I and III regarding MCH and MCHC.The mean RBC count in E trait and normal subject group were 5.01±71 million/cmm and 4.61±0.65 million/cmm respectively. There was no significant difference was found P>0.05. Mean red cell distribution width (RDW) in group I and III were 14.32 ±2.34 and 14.83±1.28 without any statistical difference (P>0.05)Conclusion: In our study there were no diagnostic significance of Blood count and RBC Indices for detection of Hb E trait. More study should be conducted to find out reliable marker of screening for Hb E carrier.Anwer Khan Modern Medical College Journal Vol. 8, No. 2: Jul 2017, P 94-99

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