Effects of postural drainage, incorporating the forced expiration technique, on pulmonary function in cystic fibrosis

Br. .I. Dis. Chest (1986) 80, 353

EFFECTS OF POSTURAL DRAINAGE, INCORPORATING THE FORCED EXPIRATION TECHNIQUE, ON PULMONARY FUNCTION IN CYSTIC FIBROSIS B. A. WEBBER, J. L. HOFMEYR, M. D. L. MORGAN AND M. E. HODSON Brompton Hospital, Fulham Road, London SW3 6HP

Summary

Detailed pulmonary function tests were performed on 12 patients with cystic fibrosis (CF) before and after 3 days treatment with postural drainage incorporating the forced expiration technique. The results following treatment showed a statistically significant improvement in FEV, (P
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Patients and Methods Twelve sequential patients with CF who had previously been taught some form of postural drainage but who had not learnt the forced expiration technique were studied. All were newly referred to the Brompton Hospital and were admitted for full medical assessment and instruction in chest physiotherapy. Acutely ill patients were excluded from the study. The mean age of the 12 patients (five males, seven females) was 19.25 years, range 15-26 years. The diagnosis of CF was established on the basis of malabsorption, chronic bronchopulmonary infection and a sweat sodium concentration of over 70 mmol/litre. No alteration to the patient’s drug regimen was made, and no patient was receiving antibiotics at the time of hospital admission. Three patients had been using bronchodilators (2.5 mg of salbutamol by nebulizer) before postural drainage. These patients were allowed to continue this routine, although when tested after the trial was completed none of them showed any significant bronchodilator response. No other patient was given a bronchodilator. Within 2 hours of admission to hospital each patient underwent pulmonary function studies. Tests included measurements of lung volumes and inspiratory airways resistance using whole body plethysmography (Feynves and Gut, Pulmostar SMB), carbon monoxide transfer factor and single breath alveolar volume measurement (P. K. Morgan Ltd, Model B Transfer Factor Apparatus) and maximal flow-volume loops (Ohio Dry Spirometer (Model 840) linked to a Prime Computer (750). All the tests were repeated, at the same time of day, 3 days later. During the intervening 72 hours each patient received physiotherapy three or four times in each 24-hour period. In the treatment periods assessment was made for each individual of the most appropriate positions for postural drainage. Chest physiotherapy included cycles of breathing exercises emphasizing inspiration, breathing control, the forced expiration technique, spontaneous coughing and expectoration whilst in a gravity-assisted position. Chest percussion and vibratory shaking were given by the physiotherapist. The cycles were continued until maximal bronchial clearance was obtained in each position. At each treatment either one or two areas of the chest were drained. As soon as the patient had learnt the breathing exercise techniques satisfactorily he was taught self-chest percussion and compression. Using the drainage positions found to be most productive, each patient carried out a further treatment himself in the evening. The weight of sputum collected during each treatment and throughout each 24-hour period was recorded. The indices of pulmonary function obtained from the laboratory tests were the forced expiratory Table 1. Patient characteristics Patient 1 2 3 4 5 6 7 8 9 10 11

Sex

Age (years)

Height (cm>

FEVl (% pred.)

WC (% pred.)

M F M F F M M F F M F

16 15 2.5 26 25 20 17 16 20 16 18

170 148 166 160 153 176 165 160 172 174 170

35.1 36.0 26.9 83.3 63.9 64.0 82.4 68.9 83.6 55.3 76.6

56.4 54.7 60.4 105.6 71.3 69.4 87.6 77.5 101.7 89.0 83.5

Predicted values taken from Cotes 1979.

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volume in one second (FEV,), forced vital capacity (FVC), total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), expiratory reserve volume (ERV), alveolar volume (VA), inspiratory airways resistance (R,,), and transfer factor (TLco). The flow-volume loop was used to obtain peak expiratory flow rate (PEFR), maximum expiratory flow rate after exhaling 50% and 75% of vital capacity (G maxS0 and kmST5)and peak inspiratory flow rate (PIFR). An index of gastrapping was obtained by the subtraction of the lo-second helium dilution alveolar volume from the plethysmographic total lung capacity (TLC-VA). This index does not exceed 500 ml in normal subjects (Denison 1981). The transfer coefficient of the accessiblepart of the lung (Kco) was calculated by dividing the diffusion capacity of the lung for carbon monoxide by the alveolar volume measured by helium dilution. The specific conductance of the airways (SG,,) was derived from the inspiratory airways resistance R, as changes in R,, do not reflect changes in lung volume. As lung size diminishes R, may appear to increase,-whereas (SG,) being a measurement per litre of lung gives a more appropriate indication of changes within the airways. The pulmonary function data before and after 3 days’ treatment were analysed using the Wilcoxon matched-pairs signed ranks test. RESULTS One patient had to be withdrawn as she developed an acute chest infection during the trial period. The characteristics of the 11 patients on entering the trial are given in Table I.

FEVl

PEFR

PI FR

loo-

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'Emax

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7 10 8 3 5 5 7 6 4 1 3 8 6 6 4 4

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1 2

3

1

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277

-

3410 1090 6.61 1.97 2100 1390 4800 3190

0.738

0.60

1899 2846 1.74

211

Mean before treatment

in pulmonary

No. of patients with decreased value

5

10 10 7

11

1

10

* = 1 record lost. Ns=not significant. tTLco mmol mix1 kPa-‘. $KCO mmol min-’ kPa-1 litre-‘.

ziT”/,,c) &“ax,s (litre/sec) SG,W (litre/sec/kPa) VA (ml) ERV (ml) TLco SI’f Kco SI$ RV (ml) TLC-VA (ml) TLC (ml) FRC (ml)

PEFR (litre/min) PIFR (litre/min) FEVl (ml) FVC (ml)

No. of patients with no change

No of patients with increased value

Table II. Changes

function

3532 1298 6.68 1.92 2029 1397 4929 3327

0.996

0.67

2094 3058 1.93

239

313

Mean after treatment

with treatment

164@4820 400-2080 3.38-8.44 1.62-2.22 1370-4350 800-3430 2800-5850 2270-4750

0.17-2.26

0.1-1.1

600-3050 95&4550 0.2-3.4

78-388

124-397

Range before treatment

1730-5050 530-2330 3.50-9.20 1.56-2.09 1250-3840 830-2970 324G6230 2570-4390

0.13-2.30

0.1-1.3

650-3280 1050-4850 0.2-4.0

85-427

130-429

Range after treatment

NS

NS

NS

NS

NS

NS

P-CO.005

NS

NS

*n=lO

NS

P
P
P
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For the whole group of patients there was a statistically significant increase in the FEV, (mean 1899-2094 ml, SD 173.7), FVC (mean 2846-3058 ml, SD 188.9), PEFR (mean 277313 litres/min, SD 31 .S), and PIFR (mean 211-239 litres/min, SD 21.5) after the 72-hour treatment period (all PP>O.O2), but less notable change in FEV,, and no significant change in FVC. Although the improvement in SG,, in our study did not reach statistical significance in the group of 11 patients, seven patients showed improvement and the mean increase was 33.8% whereas in Cochrane’s study the mean increase was 18%. Tecklin and Holsclaw (1975) investigated 26 CF patients and showed that after postural drainage there were significant increases in FVC and ERV, but in the three measurements of flow recorded, PEFR, FEV, and MMEFR (maximum mid-expiratory flow rate), the only significant increase was found in PEFR. The authors concluded that PD was only effective in clearing the large airways. In contrast, Feldman et al. (1979) in a study of chronic bronchitic and cystic fibrosis patients used a maximal flow-volume curve and suggested that the predominant improvement occurred in mid- and late expiratory flows, although they also demonstrated an increase in FEV, and PEFR in the cystic fibrosis group. In these studies postural drainage did not include the FET and it is perhaps the addition

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of this technique that makes clearance of bronchi,al secretions more effective. Moreover, the present study looked at changes in pulmonary function following 3 days’ treatment whereas the previous studies investigated changes following a single treatment. Another study (Desmond et al. 1983) looked at both immediate and long-term effects of postural drainage in CF patients. They found a deterioration in pulmonary function following a 3-week period with no treatment. Feldman et al. (1979) and Desmond et al. (1983), like the present study, showed no relationship between the quantity of sputum produced and pulmonary function. A possible explanation for improvement in pulmonary function tests in patients treated with effective physiotherapy is that airways previously blocked with secretions become unblocked. After clearing these airways secretions from the more peripheral airways may be mobilized, thus accounting for no decrease in mean daily sputum weight over the 3-day period. As these secretions are expectorated pulmonary function improves. In a short-term study on nine CF patients comparing cough alone, with postural drainage (deBoeck and Zinman 1984) no changes were found in FEV,, FVC or PEFR following postural drainage. The authors suggested that cough alone may be a satisfactory alternative method of treatment and that the long-term effects of treatment needed investigation as the aim of chest physiotherapy is to maintain pulmonary function. FET has been shown to be more effective than cough with respect to radioaerosol clearance and sputum production (Sutton et al. 1983). The present study provides objective evidence of improvement in pulmonary function when effective postural drainage including the FET is used in the treatment of CF patients. ACKNOWLEDGEMENTS We would like to thank Dr J. C. Batten for allowing us to study his patients; Mr D. Cramer and his staff in the Lung Function Department and Mrs H. Booker for their help; Miss Sally Hockley for secretarial assistance; Miss Rehahn for statistical advice and the Cystic Fibrosis Research Trust for financial support for JLH. REFERENCES Cochrane, G. M., Webber, B. A. &Clarke, S. W. (1977) Effects of sputum on pulmonary function. Br. med. J. 2, 1181-1183. Cotes, J. E. (1979) Lung Function, 4th edn. Oxford: Blackwell. deBoeck, C. & Zinman, R. (1984) Cough versus chest physiotherapy. Am. Rev. resp. Dis. 129,182184. Denison, D. (1981) Physiology. In: Clinical Investigation of Respiratory Disease, Chapter 3 (ed. T. J. H. Clark). London: Chapman & Hall. Desmond, K. J., Schwenk, W. F., Thomas, E., Beaudry, P. H. & Coates, A. L. (1983) Immediate and long-term effects of chest physiotherapy in patients with cystic fibrosis. J. Pediat. 103, 538-542. Feldman, J., Traver, G. A. & Taussig, L. M. (1979) Maximal expiratory flows after postural drainage. Am. Rev. resp. Dis. 119, 23%245. Pryor, J. A. & Webber, B. A. (1979) An evaluation of the forced expiration technique as an adjunct to postural drainage. Physiotherapy 6.5, 304-307. Pryor, J. A., Webber, B. A., Hodson, M. E. & Batten, J. C. (1979) Evaluation of the forced

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expiration technique as an adjunct to postural drainage in treatment of cystic fibrosis. Br. med. J. 2, 417-418. Sutton, P. P., Parker, R. A., Webber, B. A., Newman, S. P., Garland, N., Lopez-Vidriero, M. T., Pavia, D. & Clarke, S. W. (1983) Assessment of the forced expiration technique, postural drainage and directed coughing in chest physiotherapy. Eur. J. resp. Dis. 64, 62-68. Tecklin, J. S. & Holsclaw, D. S. (1975) Evaluation of bronchial drainage in patients with cystic fibrosis. Physical Therapy 5.5, 1081-1084.