Benefits of a Multidisciplinary Pulmonary Rehabilitation Program

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Benefits of aMultidisciplinary Pulmonary Rehabilitation Program To the Editor: The rigorous study reported by Niederman et al' in the April1991 issue of Chest emphasiz.es the beneficial action of multidisciplinary pulmonary rehabilitation programs for patients with chronic obstructive lung disease (COLD). It tends to prove that improvements may be obtained independently from the degree of gravity of pulmonary disease. and that no patient is "too sick" or "too well" to benefit from such a program. Our experience as a whole is in agreement with this conclusion. We would like to report our own experience, and to point out some differences in results or in interpretation of our observations. It is surprising that training of these 33 patients did not induce any significant change in FEV,. whereas the endurance exercise capacity improved considerably. Moreover, the authors considered the Increase in Vo2 max small, but the increase from 845.8 to 1.005.3 ml!min is an inc.rease of 19 percent. This increase in Vo1 max is, in fact, important and is even superior to what has been observed among healthy sedentary adults, who manage to increase their Vo2 max by only 10 or 15 percent after a 2-month training regimen made up of 3 to 5 weekly sessions. It is unfortunate that this improvement was not significant in their series, but it is nevertheless an important improvement, superior to what we have obtained with similar patients. In the Toki-Eder Medical Center, we conducted a study on a series of258 patients with chronic ventilatory insufficiency: 226 patients with exercise training and 32 control patients who benefited from a program of physical education and ventilatory physiotherapy but had refused exercise training (Table 1). Their mean age was 57.0 :!: 10.6 years. Their mean tobacco use was 19.1 :!: 26.1 pack-years. The mean training duration was 4.2 :!: 2.2 weeks. We found that FEY, was very highly significantly increased (p < 0.001) for the 226 trained patients, but the increase was not significant for the 32 untrained control patients. Ukewise, the increase in Vo1 max (or symptom-limited Vo1 ) was highly significant (p < 0.01) among the trained patients, but it was nil for untrained control patients. In anothe.r series of 122 patients with COLD, we included measurement of plethysmographic airway resistance before and after rehabilitation. We compared the data on 80 trained subjects (mean age. 59.6:!: 9.7 years) with the data on 42 control patients who had undergone a program of physical educati.on and ventilatory physiotherapy but not exercise training (mean age 59.9 :!: 10.9 years) (Table 2). The control subjects were selected in such a way that the ages (mean values and standard deviations) were the same in the two series. For trained patients. the improvement in FEY, (which increased) as well as in airway resistance (which decreased) was very highly significant

Table 1-&ault. m258 Patift~U With Cltronk V~

~-~·

Variable

Before Rehahilitation

After Rehabilitation

p Trained P!tients VC,L (BTPS) 2.97 :!: 0.69 3.13 :!: 0.74 <0.001 FEV1, L (BTPS) 1.57 :t 0.43 1.69 :!: 0.44 <0.001 Maximum tolerated 85.96:!: 29.75 100.88 :!: 33.36 <0.001 power, Wt Symptom-limited Vo1 , 1.30 :!: 0.48 1.41 :!: 0.49 <0.01 Vmin(STPD) Untrained patients VC. L (BTPS) 2.84 :t 0.89 2.98 :!: 0.83 <0.02 FEY,, L(BTPS) 1.48 :!: 0.65 1.56 :!: 0.61 >0.10 Maximum tolerated 84.37 :!: 26.87 90.94 :!: 29.98 <0.01 power. Wt Symptom-limited Yo1, 1.27 :!: 0.53 1.29 :!: 0.44 >0.10 Vmin(STPD)

·vc- vital ·ty. tOn the ~ercise test. Table~

in 122 P~ W'llh cow•

Variable

Before Rehabilitation

After Rehabilitation

p

3.08:!: 0.82 1.62:!: 0.60 2.8 :!:1.3

3.29:!: 0.90 1.75:!: 0.65 2.3:!: 0.9

<0.001 <0.001 <0.001

2.85:!: 0.97 1.60:!: 0.85 2.7:!: 1.4

3.05:!: 1.18 1.74:!: 1.05 2.8:!: 1.7

<0.05 <0.10 >0.10

Trained patients VC,L(BTPS) FEY I' L (BTPS) Raw em H O • L'1•s· 1

Untrained pa\ients VC,L(BTPS) FEVI' L (BTPS) RaW

em ~O•L''•s·•

"Raw- airway resistance.

(p < 0.001), which once again was not the case for untrained control patients. As concerns the modalities ofretraining. the patients of Niederman et al were trained three times a week. for 1 h per session (three 20-min sequences). We thought that 60 min of effective training in a session was a lot, especially for patients with COLD; it is the maximal duration of sessions recommended by the American College of Sports Medicine for healthy sedentary adults who decide to resume a sports activity. We train our patients 5 times a week. at the rate of 40 min per session (4 times10 min with intercalary rests), which gives 3 h 20 min of training over 5 days, instead of 3 h over 3 days per week for the patients of Niederman et al. This retraining has an effect on Vo1 max (the same in relative value as for healthy sedentary adults, but the absolute levels at the beginning and end oftraining are obviously lower) and a much more important effect on endurance exercise capacity (as is also the case for healthy sedentary adults). MorecM!r, there is no difference in nature between training of a patient with COLD, training of a healthy sedentary adult, and training of a sportsman, the only differences being quantitative. The principles of training are the same, differing only in the levels of physical fitness and the work loads that the subjects can tolerate. Some observations of Niederman et al are in keeping with ours, specifically. "the increases in Vo1 max, maximal 0 1 pulse max, and maximal cycle watts were greatest in those with the lowest initial values Communlc:atlon8 to the Editor

and least in those with the highest initial values.· Sports physicians know that it is also true among healthy sedentary adults who begin training. In regard to the small increase in Vo2 max observed for their patients, the authors think that this would have been more important if they had used a treadmill instead of a cycle ergometer. We doubt this, because it is not what we have observed. Hickson and Rosenkoetter' submitted 12 subjects to endurance training (cycle ergometer and running) for 40 min daily, 6 days a week for 10 weeks. The mean increase in Vo2 max was 25 percent with the cycle ergometer and 20 percent with the treadmill. These findings illustrate the influence of protocol on the test result. Concerning the opportunities for improvement of physical fitness of the most affected patients, we think that the discussion has been biased, for among the patients whose VE max and Vo2 max are the most lowered, some are limited by important lung reshaping, while others are only committed to a sedentary life-style. The latter patients will be more imprdved by a retraining program. The others will benefit from their training, though perhaps more in terms of psychological criteria than functional performance. Globally speaking, we are in agreement with the conclusion of authors that pulmonary rehabilitation can reasonably be offered to any patient with chronic lung disease with the expectation that improvement can occur regardless of the severity of the underlying disease process. Robert f. Menier; M.D., LAboratory of Physiowgy and FunctWnol Explcraticn. Medical School and Univemtlj Hospital Dupuytren; and Jerome Talmud, M.D., Medical Center Toki-Eder; Umoges, France Reprint requests: Dr. Menier, CHRU Dupuytren, Explcraticn FonctloneUe, 87042 Umoges, France REFERENCES

1 Niederman MS, Clemente PH, Fein AM, Feinsilver SH, Robinson DA, llowite JS, et al. Benefits of a multidisciplinary pulmonary rehabilitation program: improvements are independent of lung function. Chest 1991; 99:798-804 2 Hickson RC, Rosenkoetter MA. Reduced training frequencies and maintenance of increased aerobic power. Med Sci Sports Exerc 1981; 13:13-6

To the Editor: We find the observations reported by Drs. Menier and Talmud to be quite interesting. and we are gratified that their observations are similar to our own. They have observed many of the same benefits from a multidisciplinary rehabilitation program that we have previously reported. One of the major di.fferences between their data and ours is that they observed a statistically significant increase in maximal oxygen consumption after pulmonary rehabilitation. As a percentage, this increase in maximal oxygen consumption is slightly less than we have observed, but it is statistically significant, presumably because of the large number of patients who were evaluated. It is possible that an even more significant increase in maximal oxygen consumption might have occurred if patients had been train.ed for a longer time period. A mean training duration of 4 weeks was used, whereas our program was oonducted for a 9-week period. Similarly, they observed a significant increase in spirometric values and improved airway resistance measurements. Although these changes were numerically relatively small,

they assumed statistical significance because of the large number of patients studied. One other di.fference pointed out by Drs. Menier and Talmud is that their training protocol is for patients to exercise 5 days per week, whereas our protocol involved exercise for 3 days per week. Our sessions were generally longer than theirs, but with suitable rest periods, we have not found this to be a difficulty for our patients. Clearly, there will be some patients who cannot tolerate exercise sessions for as long as 60 min; the length of these sessions should be individualized. Overall, however, it is reassuring and of great importance that other investigators have been able to oonfirm the observation that individuals of all degrees of severity stand to benefit from a multidisciplinary rehabilitation program. Based on these observations, we hope that patients with COPD will continue to be enrolled in pulmonary rehabilitation programs. Michael S. Niedenoon, M.D., Alan M. Fein, M.D., Steven H. Feinsilver, M.D., and Jonathan S. Ilowite, M.D., Pulmonary and Critical Care Medicine Division, Winthrop-Universitlj Hospital,

Mineola, New York

Pulmonary Edema Associated With Radiocontrast Material To the Editor: I was intrigued by the case report by Kozlowski and Kollef,' which appeared in the August 1992 edition of Chest. Their discussion of the putative mechanisms involved in the development of noncardiogenic pulmonary edema following administration of radiocontrast material (RCM) is praiseworthy. While the case presented oould support a diagnosis of direct endothellal injury from RCM administration based on the mechanisms reviewed, it does not readily depict a clinical scenario that would result in pulmonary edema due to acute upper ai.rway obstruction. I would Uke to offer an alternative hypothesis for the oondition described. The phenomenon of negative pressure pulmonary edema is believed to occur when excessive inspiratory force is directed against an obstructed upper airway (Miiller maneuver), resulting in large swings in intrathoracic pressure. In most studies, the associated development of increased extravascular lung water is related to the generation of extremely negative transpulmonary pressures during the inspiratory effort.2.3 The oondition most often occurs in children or relatively young healthy adults and is rare in those situations in which, for mechanical reasons, significantly negative transpulmonary pressures cannot be generated (eg, in elderly patients and in flail chest).3 1t is exceedingly oommon for individuals to experience a sensation of neck Mfullness" with RCM infusion, and while this patient certainly demonstrated respiratory compromise, nothing compatible with severe inspiratory stridor or MUller maneuver-like efforts is described. The rapidity (1 min) with which the dyspnea appeared in the absence of these respiratory movements favors a direct effect of RCM on pulmonary and perhaps systemic vasculature, possibly by mechanisms similar to those seen in a variety of animal models of oxidantmediated acute endothellallung injury.•-5 This injury can be dose dependent, and a mild form oould be expected to cause a transient acute edematous lung injury, as in the case described. Shawn E. Wright, M.D., Division of Pulmonary Diseases/Critical Care Medicine, Unlvemtfj ofTaas Health Sciences Center, San Antonio CHEST I 105 I 2 I FEBRUARY, 1994 641