- Email: [email protected]
Differences between Slow and Fast Vital Capacities
there is no expiratory obstruction present according to the ratio FEVt/FVC. It is very likely that due to the increasing use of the "electronic' spirometers which measure volume by e1ectronic integration of expiratory flows, the use of the FVC will increase as well. The influence of the FVC on tests which malce use of this vital capacity instead of a slow vital capacity, such as the voIume-flow curves, is unknown. In spite of previous articles pointing out the differences between both vital capacities1- a the type of vital capacity used is often not specified in the medical literature.
Rafael Pad, M.D., and Th0rn08 W. oon tier Marie, Ph.D. Lung FoocHon Ltiboratorr/, Department of Internal Medicine, UnfoerritU H 0IfJ1ItIl., Grtmingen, The Netheftantls
1 Gibson JC, Hugh-Jones P. The measurement of the total lung volume and breathing capacity. Clin Sci 1949; 7: 185-216 2 Scarrone LA, Levin R, Barach AL. Variations in the vital capacity measurement in patients with bronchial asthma and pulmonary emphysema. N Engl J 1955; 252:
Moo
57-59
3 Anderhub HP, Keller R, Herzog H. Spirometrische Untersuchung der forzierten VitaDcapacitiit und maximalen Atemstromstiirke bei 13798 Personen. Dtsch med Wschr 1974; 99:33-38
To the Editor:
We believe Drs. Peset and van der Mark have drawn attention to a real problem which is slightly different from the one we addressed, although we did mention it. In old normals and particularly in patients with airway obstruction, RV and therefore VC is dynamically determined; that is, during a VC maneuver the subject never stops breathing out until he breathes in. Thus, the VC depends on the length of time the patient spends breathing out, and this time tends to be less during FVC than during slow VC maneuvers. This is the reason that FVC maneuvers that do not consume at least 6 sec should be discarded. However, this guideline is not perfect and an FVC that takes 12 sec will, in most patients and old normal subjects, be distinctly larger than one that takes 6 sec. A slow VC which takes 20 sec wiD be even larger. An inspiratory VC will depend on how long the patient spent expiring to RV before the inspiratory maneuver. Because of this, many distinguished workers do not use the FEVt/FVC, but the FEV 1. If the FEVl/FVC is to be used in diagnostic work, some effort must be made to standardize the duration of the FVC, which is why NIH guidelines recommend a maneuver taking at least 6 sec. Our study concentrated upon a relatively small group of patients with obstructive disease in whom FVC were less than slow VC and this difference could not be accounted for in terms of expiratory time. N. R. AnthonLten, M.D. Director, BespiratorrJ Dl~
UnWerritu of Manitoba,
Winnipeg
378 COMMUNICATIONS TO THE EDITOR
Subclavicular Approach for Biopsy of Apical Lung Lesions To the Editor: Obtaining a tissue diagnosis of apical lung lesions is not always easy. Yet, before major operations and/or radiotherapy can be planned, it is necessary to know the nature of the lesion. Dartt recently reviewed the subject and has suggested that supraclavicular thoracotomy affords a convenient solution. In my experience, this approach is difBcu1t because of the overlying vessels and nerves. Furthermore, I share their disappointing experiences with more traditional approaches such as bronchoscopy, transcarinal needle biopsy, mediastinoscopy, anterior mediastinotomy and percutaneous needle biopsy. For many years we have used the subclavicular approach for removing the first and cervical ribs for thoracic outlet syndrome. 2 Occasionally, we received patients with apical pulmonary lesions with symptoms and signs suggestive of thoracic outlet syndrome. In these instances we proceeded to remove the first rib by the subclavicular approach. Palpation usually revealed induration of the rib bed. Biopsy revealed tumor on frozen section. Since this procedure is simple, safe, and effective, it is suggested as an approach to the problem of diagnosis of occult apical lung lesions. The procedure to be described has been modified little since we first used it. The patient lies supine with the ipsilateral arm abducted 90 degrees on an arm board. The skin incision is made about one inch below and parallel to the medial part of the clavicle. The fibers of the pectoralis major muscle can be split near the mid clavicular plane and separated by retractors. Some of the medial fibers may require transection. A narrow Deaver retractor is best used cephalad and laterally as it easily follows the course of the first rib. Next, the underlying costoclavicular fascia is incised over the anterior extremity of the first rib. The underlying axillary fat and vessels are separated from the anterolateral surface of the first rib by finger dissection as the tip of the Deaver retractor follows. The periosteum of the anterolateral aspect of the first rib is peeled off with an elevator. The tip of the elevator is then carefully inserted between rib and periosteum of the posterior aspect of the anterior extremity of the rib. Next, the medial edge of the DO is freed including the tendon of the scalenus anticus muscle. The rib is then removed piecemeal starting anteriorly and progressing posteriorly as periosteum is freed. In this manner, the whole rib can be removed. Usually if tumor is present, it can be palpated and biopsied in the bed of the first rib. It is possible to open the underlying pleura to explore the apex of the pleural cavity. There is little danger of injuring vessels and nerves as they are retracted laterally beneath the Deaver. We have never encountered a serious complication using this approach in over 100 0perations for various indications. Daoid V. Pecot'G, M.D. Veterana Administration Centet-,
Wilmington, DeltJwtJf'S
REFERENCES 1 Dart CH. Supraclavicular thoracotomy for diagnosis of apical lung and superior mediastinum lesions. Ann Thor Surg 1979; 28:90-93 2 Hamlin H, Pecora DV. Subclavicular segmental resection of first rib for correction of subjacent neurovascular compression. Am J Surg 1969; 117:754-58
CHEST, 79: 3, MARCH, 1981
Rafael Pad, M.D., and Th0rn08 W. oon tier Marie, Ph.D. Lung FoocHon Ltiboratorr/, Department of Internal Medicine, UnfoerritU H 0IfJ1ItIl., Grtmingen, The Netheftantls
1 Gibson JC, Hugh-Jones P. The measurement of the total lung volume and breathing capacity. Clin Sci 1949; 7: 185-216 2 Scarrone LA, Levin R, Barach AL. Variations in the vital capacity measurement in patients with bronchial asthma and pulmonary emphysema. N Engl J 1955; 252:
Moo
57-59
3 Anderhub HP, Keller R, Herzog H. Spirometrische Untersuchung der forzierten VitaDcapacitiit und maximalen Atemstromstiirke bei 13798 Personen. Dtsch med Wschr 1974; 99:33-38
To the Editor:
We believe Drs. Peset and van der Mark have drawn attention to a real problem which is slightly different from the one we addressed, although we did mention it. In old normals and particularly in patients with airway obstruction, RV and therefore VC is dynamically determined; that is, during a VC maneuver the subject never stops breathing out until he breathes in. Thus, the VC depends on the length of time the patient spends breathing out, and this time tends to be less during FVC than during slow VC maneuvers. This is the reason that FVC maneuvers that do not consume at least 6 sec should be discarded. However, this guideline is not perfect and an FVC that takes 12 sec will, in most patients and old normal subjects, be distinctly larger than one that takes 6 sec. A slow VC which takes 20 sec wiD be even larger. An inspiratory VC will depend on how long the patient spent expiring to RV before the inspiratory maneuver. Because of this, many distinguished workers do not use the FEVt/FVC, but the FEV 1. If the FEVl/FVC is to be used in diagnostic work, some effort must be made to standardize the duration of the FVC, which is why NIH guidelines recommend a maneuver taking at least 6 sec. Our study concentrated upon a relatively small group of patients with obstructive disease in whom FVC were less than slow VC and this difference could not be accounted for in terms of expiratory time. N. R. AnthonLten, M.D. Director, BespiratorrJ Dl~
UnWerritu of Manitoba,
Winnipeg
378 COMMUNICATIONS TO THE EDITOR
Subclavicular Approach for Biopsy of Apical Lung Lesions To the Editor: Obtaining a tissue diagnosis of apical lung lesions is not always easy. Yet, before major operations and/or radiotherapy can be planned, it is necessary to know the nature of the lesion. Dartt recently reviewed the subject and has suggested that supraclavicular thoracotomy affords a convenient solution. In my experience, this approach is difBcu1t because of the overlying vessels and nerves. Furthermore, I share their disappointing experiences with more traditional approaches such as bronchoscopy, transcarinal needle biopsy, mediastinoscopy, anterior mediastinotomy and percutaneous needle biopsy. For many years we have used the subclavicular approach for removing the first and cervical ribs for thoracic outlet syndrome. 2 Occasionally, we received patients with apical pulmonary lesions with symptoms and signs suggestive of thoracic outlet syndrome. In these instances we proceeded to remove the first rib by the subclavicular approach. Palpation usually revealed induration of the rib bed. Biopsy revealed tumor on frozen section. Since this procedure is simple, safe, and effective, it is suggested as an approach to the problem of diagnosis of occult apical lung lesions. The procedure to be described has been modified little since we first used it. The patient lies supine with the ipsilateral arm abducted 90 degrees on an arm board. The skin incision is made about one inch below and parallel to the medial part of the clavicle. The fibers of the pectoralis major muscle can be split near the mid clavicular plane and separated by retractors. Some of the medial fibers may require transection. A narrow Deaver retractor is best used cephalad and laterally as it easily follows the course of the first rib. Next, the underlying costoclavicular fascia is incised over the anterior extremity of the first rib. The underlying axillary fat and vessels are separated from the anterolateral surface of the first rib by finger dissection as the tip of the Deaver retractor follows. The periosteum of the anterolateral aspect of the first rib is peeled off with an elevator. The tip of the elevator is then carefully inserted between rib and periosteum of the posterior aspect of the anterior extremity of the rib. Next, the medial edge of the DO is freed including the tendon of the scalenus anticus muscle. The rib is then removed piecemeal starting anteriorly and progressing posteriorly as periosteum is freed. In this manner, the whole rib can be removed. Usually if tumor is present, it can be palpated and biopsied in the bed of the first rib. It is possible to open the underlying pleura to explore the apex of the pleural cavity. There is little danger of injuring vessels and nerves as they are retracted laterally beneath the Deaver. We have never encountered a serious complication using this approach in over 100 0perations for various indications. Daoid V. Pecot'G, M.D. Veterana Administration Centet-,
Wilmington, DeltJwtJf'S
REFERENCES 1 Dart CH. Supraclavicular thoracotomy for diagnosis of apical lung and superior mediastinum lesions. Ann Thor Surg 1979; 28:90-93 2 Hamlin H, Pecora DV. Subclavicular segmental resection of first rib for correction of subjacent neurovascular compression. Am J Surg 1969; 117:754-58
CHEST, 79: 3, MARCH, 1981