Studies on various pulmonary functions on tuberculosis patients
Part 1. Lung Volumes and Ventilatory Capacities in Tuberculosis(TB) Patients
A) Studies on Unoperated Patients
Thirty TB patients who have been admitted to the Masan Transportation Sanatorium were selected for the study along with ten healthy men acting as the control group. Patients were divided into three equal groups, the minimal(Min), moderately-advanced(MA) and far-advanced(FA), dependent upon the severity of
disease. Ages of subjects ranged from 20 to 48 years old, with the average of 33.
The vital capacity and its subdivisions, the residual volume, the maximal breathing capacity, the minute volume and the resting oxygen consumption were measured and the data obtained from each group was compared with one another.
Results may be briefly summarized as follows:
1. The vital capacity as well as the inspiratory capacity and the expiratory reserve volume showed a moderate reduction in the FA group, suggesting a reduction in the ventilatory volume of the lung as a result of the extensive lesion on this group.
2. The residual volume increased progressively as the severity of TN increased.
3. The maximal breathing capacity was lowered while the timed vital capacity was delayed in the FA group.
4. The calculated values of both the Leslie's index and the index of air trapping were significantly increased.
5. Neither the capacity ratio nor the calculated air velocity index showed any significant difference among various groups, suggesting that the air-way resistance is not altered in TB patients.
6. The minute volume as well as the resting oxygen consumption shoed no significant difference among various groups.
7. These results are considered to be largely due to both the emphysematous and fibrotic changes of the lung, which are known to occur secondarily in the far-advanced TB patients.
B) Studies on Operated Patients
Various surgical operations such as pneumonectomy(3 cases), thoracoplasty(4 cases), left upper lobectomy(4 cases) and right upper lobectomy(5 cases) were preformed on pulmonary TB patients when they were considered to improve the disease. Ages of patients ranged from 30 to 47 years old, with the average of 35.
Measurements of various lung volumes an d of ventilatory capacities, as indicated in the previous section, were made before and after(3 to 12 months) the operation and results are compared as summarized below:
1. The vital capacity as well as the inspiratory capacity and the expiratory reserve volume were reduced most after the pneumonectomy, moderately after the left or right upper lobectomy and least after the thoracoplasty.
2. The R.V./T.L.C. ratio was increased by 14.3% and 5.5% after left upper lobectomy and pneumonectomy, respectively, but it showed little change after either right upper lobectomy or thoracoplasty. The increased in this ratio seems to indicate that the remaining lung tissue overexpands in order to fill space provided by the resection.
3. The maximal breathing capacity was lowered most after both the pneumonectomy(by 28.4%) and the thoracoplasty(by 19.3%), and decreased less after the left or right upper lobectomy.
4. The timed vital capacity showed slight improvement(by 5%) in all groups after the surgery.
5. Calculated values of the air velocity index, the capacity ratio, the Leslie's index and the index of air trapping showed no significant change in all groups after the surgery.
6. The resting minute volume was significantly increased after the pneumonectomy, while the resting oxygen consumption was not altered, with the result that the ventilation equivalent was raised in this group.
This is probably due to the reduction in the surface area available for the gas exchange after the pneumonectomy, which would invariably lower the overall efficiency of the gas exchange. No significant changes were seen in other groups.
Part 2. Various Pressure-Volume Relationships of the Respiratory Appraratus in Tuberculosis(TB) Patients
A) Studies on Unoperated Patients
Various pressure-volume relationships were studied in 5 healthy men(control group) as well as in 5 TB patients who were to receive various surgical treatments as desired. Passive pressures exerted by the respiratory apparatus, such as the lung, the thoraciccage(including the diaphragm) and the total respiratory system, were first determined under various lung volumes and then the corresponding compliance values at the resting lung volume were computed. The measurement of the lung pressure was made by a means of the intra esophageal balloon method and the thoracic cage pressure was calculated by substracting the lung pressure from the total respiratory pressure(or the relaxation pressure). As the next step, both the maximum inspiratory and expiratory pressures were determined under various lung volumes by a mercury manometer.
Results are compared between the two groups and may be briefly summarized as follows:
1. Various pressure-volume curves of the respiratory apparatus such as the lung, the thoracic cage and total respiratory system were not significantly different between two groups, as long as the lung volumes were expressed as percent of the vital capacity.
2. Since values of the vital capacity were not identical in the two groups, compliance values were computed for a comparison of the elasticity of the respiratory apparatus.
a. The lung compliance was 0.227 and 0.217 ℓ/cmH2O in the control and TB group, respectively.
b. The thoracic cage compliance was 0.186 and 0.118ℓ/cmH2O in the control and TB group, respectively, indicating that the thoracic cage is much less elastic in the patient as compared to the control.
c. The compliance of the total respiratory apparatus was 0.100 and 0.066ℓ/cmH2O in the control and TB group, respectively. This lowered elasticity in the TB group is due to the loss of elasticity of the thoracic cage.
3. Both the maximum inspiratory and expiratory pressures were lowered in the TB group as compared to the control. On the average, the reduction in the maximum expiratory pressure was greater than that of the maximum inspiratory pressure.
B) Studies on Operated Patients
Various surgical operations such as pneumonectomy(3 cases), thoracoplasty(4 cases), left upper lobectomy(5 cases) and right upper lobectomy(5 cases) were performed on pulmonary TB patients and the pressure volume relationships of the respiratory apparatus were studied on these patients at least 3 months after the operation. The same methods as employed in the previous study(Part 2, Section A) were also adopted for this series of investigation. Although subjects in this series were different from those who were used in the previous series(Part 2, Section A) as the TB group, the data obtained were compared with them, with the hope that this comparison would be of some help in evaluating the effect of various surgeries in the pulmonary functions of these patients. The results may be briefly summarized as follows:
1. In the pneumonectomized goup, the reduction in the vital capacity was greatest and compliance values of the lung(0.091ℓ/cmH2)), the thoracic cage(0.103ℓ/cmH2O) and the total respiratory apparatus(0.044ℓ/cmH2O) were approximately one-half of the corresponding values obtained in the non-operated FA group.
2. In the case of thoracoplasty, compliance values of the thoracic cage(0.11ℓ/cmH2O) and of the total respiratory apparatus(0.055ℓ/cmH2O) were nearly as low as those un the pneumonectomized group while the lung compliance(0.143ℓ/cmH2O) was higher than the latter.
3. In the case of left upper lobectomy, compliance values of the thoracic cage and of the total respiratory apparatus were similar to those in the case of thoracoplasty, while the lung compliance was as low as 0.104ℓ/cmH2O.
4. In the case of right upper lobectomy, various compliance values were similar to those obtained from the group of thoracoplasty.
5. In general, the lung compliance was reduced in proportion to the extent of the decrease in vital capacity. The compliance of the thoracic cage was reduced to the same extent in all groups.
6. Both the maximum inspiratory and expiratory pressures were lowered in all groups. The greatest reduction was seen in the pneumonectomized group whereas the least reduction was seen in the group of right upper lobectomy. These results again suggest that the reduction of these maximum respiratory pressures in proportional to the extent of the decrease in vital capacity.