Exercise Testing in Servicemen with Asthma and its application to the assessment of Potential Recruits

Transcription

1 J R Army Med Corps, 1983; 129: Exercise Tesing in Servicemen wih Ashma and is applicaion o he assessmen of Poenial Recruis Col J Carson MB, FRCP, DTM&H, LjRAMC Maj C R Winfield MA, BM, MRCP, RAMC* Army Ches Cenre, Cambridge Miliary Hospial SUMMARY: A sandard exercise es was performed on defined groups of normal and ashmaic personnel and recruis wih a hisory of childhood ashma. Normal servicemen had a mean Exercise Labiliy Index (ELl) of 7.81, and we ook an ELl of over 15 o be abnormal. By his crierion we found ha 91.7% of service personnel wih ashma who could no pass h e army Basic Finess Tes (BFT) were abnormal. Conversely among service personnel wih ashma wih an ELl above 15 we found 89.8% could no pass he BFT. Among poenial recruis wih a hisory of childhood ashma considered o be in remi'ision we found 27.1% had minor sympoms and of hese 51.7% were abnormal. Among poenial recruis who admied no sympoms whaever for a leas one year 20.5% were abnormal. We conclude ha formal exercise esing of recruis wih childhood ashma would deec a significan number wih abnormal labiliy likely o inerfere wih miliary raining. Inroducion I is recognized ha increased bronchial labiliy can be demonsraed by appropriae exercise esing in ashmaic subjecs and in ashmaics in apparen remission" 2. I is also recognized ha a hisory of childhood ashma presens a problem in he assessmen of poenial recruis 3 and such a hisory is presen in many who develop ashma during miliary service. We have carried ou a sudy of exercise relaed bronchiallabiliy in service personnel wih and wihou ashma, in ashmaic recruis, and in poenial recruis wih a hisory of childhood ashma wih a view o assessing he usefulness of a sandard exercise es in recrui selecion. Mehods Exercise Tes A sandard exercise es was performed in all subjecs. This consised of exercising on a readmill a six kilomeres per hour on a en degree slope for six minues. All ess were performed in he morning a ambien emperaure in a gymnasium. The emperaure range was from 17 o 25 Celsius. The Forced Expiraory Volume in one second (FEV 1) and Forced Vial Capaciy (FVC) were measured using a dry spiromeer (Vialograph Ld) using he "BTPS" scale. The resuls were recorded o he neares 0.5 lires excep when a "Vialograph" flow analyser was used when he resuls were recorded o 0.01 lires. FEV 1 and FVC were recorded a res, immediaely on compleion of exercise, hen a one, hree, five, seven nine, welve and fifeen minues, bu coninued up o hiry minues afer exercise if a progressive fall occurred. All resuls were sudied o exclude hose suggesive of a non-maximum expiraory effor. The subjecs had no received eiher disodium cromoglycae or a bronchodilaor on he day of he es. The resing FEV 1 was considered abnormal when i was less han 70% of he resing FVC. An "Exercise Labiliy Index" (ELl) was calculaed from he formula: Highes FEV 1 - Lowes FEV 1 Resing FEV) x 100 Subjecs We divided our subjecs ino six main groups. Group 1 A conrol group of servicemen who had no hisory of ashma or hay-fever and who had no respiraory illness. They had all successfully compleed recrui raining. Group 2 Servicemen who had presened wih bronchial ashma a some ime afer compleing

2 J Carson and C R Winfield recrui raining and who were unable o pass he army "Basic Finess Tes" (BFT) because of exercise induced ashma. Group 3 Servicemen as defined in Group 2 bu who were able o pass he BFT. Group 4 Recruis who presened wih exercise induced ashma in basic miliary raining. Group 5 Poenial recruis wih a hisory of childhood ashma who claimed o be in remission bu who, on criical quesioning, admied sympoms of wheeze, however rivial, in he previous year. Group 6 Poenial recruis as defined in Group 5 excep ha hey denied any sympoms of ashma in he previous year despie criical quesioning. We also esed a small number of servicewomen wih ashma. Resuls Group 29 subjecs were esed, one wice on differen days o produce 30 observaions. Age> ranged from 17 o 34 years (mean 20.4) and he resing FEV 1 ranged from 3.55L o 5.90L (mean 4.58 ± 1.l0L). All resuls were normal a res. The ELT was beween 2.88 and (mean 7.81 ± 5.16). Group 2 42 subjecs aged from 17 o 41 (mean 27.1) were esed. The resing FEV, lay beween 1.50L and 6.50L (mean 3.97 ± 1.80) and 10 (23.8%) were abnormal a res. The ELT was beween 6.4 and 68.6 (mean 31.72±29.96) and only four subjecs (9.5%) had an ELl below 15. The disribuion of ELl is shown in Figure 1. J --' '5... 2O... Z5_ 30-'5--~o --:'"l fo 6' l:xerciae..bili), Index Fig. 1 Disribuion of Exercise Labiliy Index in 42 ashmaic servicemen unable o pass Basic Finess Tes If:lcrci J..biliy Index Fig. 2 Disribuion of Exercise Labiliy Index in 16 aeshmaic servicemen who could pass Basic Finess Tes Group 3 16 subjecs aged from 16 o 38 (mean 22.75) were esed. The resing FEV 1 was from 3.10L o 5.85L (mean 4.48 ± 1.58L) and wo were abnormal a res (12.5%). The ELl was beween 3.8 and 30.6 (mean ± 16.3) and was less han 15 in 12 subjecs (75%). Figure 2. Group 4 50 subjecs aged from 16 o 21 (mean 17.88) were esed. The resing FEV 1 was from 1.10L o 5.35L (mean 4.16 ± l.72l) and nine were abnormal a res (18%). The ELT was from 4.21 o 72.7 (mean ± 31.15). The mean ELT of 35 who gave a hisory of childhood ashma was similar o ha of he group as a whole (25.78). (Figure 3). Excrc1ce lcbil1y Index ~ Indiea"a 3 ~bj.ea.ih '",p""" onl, on..,. arenuau. rum1.. wi. lood Fig. 3 Disribuion of Exercise Labiliy Index in 50 male recruis developing sympoms of exercise induced ashma during basic raining In his group 16 subjecs had an ELT of less han 15 (32%) and hree of hese wih no hisory of childhood ashma only had sympoms on very srenuous susained aciviy. 15

3 16 Group 5 29 subjecs aged from 16 o 23 (mean 17.55) were esed. The resing FEV! was from 2.45L o 6.15L (mean 4.32± 1.69L) and wo were abnormal a res (6.9%). The ELl lay beween 4.1 and 39.8 (mean ± 19.49) and 14 subjecs had an ELl of less han 15 (48.3%) (Figure 4). 10 X!rciae labil1:r Index Fig. 4 Disribuion of Exercise Labiliy Index in 29 previously ashmaic recruis referred 'In Remission' bu who on close quesioning had had minor sympoms in he previous welve monhs :I! o i ~ 5 rh. n Fig. 5 Disribuion of Exercise LabiIiy Index in 78 recruis wih a hisory of childhood ashma who appeared o be in complee remission Exercise Tesing in Servicemen wih Ashma and is applicaion o he assessmen of Poenial Recruis Group 6 78 subjecs aged 15 o 25 (mean 18.5) were esed. The resing FEV! was from 2.75L o 6.05L (mean 4.48 ± 1.43L) and six were abnormal (7.7%). The ELl lay from 2.0 o (mean ± 15.59) and 62 subjecs had an ELl of less han 15 (79.5%) (Figure 5). Service women We also esed hree servicewomen wih mild ashma who could pass he BFT. Two had a normal ELl and one an ELl of A furher six servicewomen who could no pass a BFT because of wheeze had a range of ELl from o (mean 38.3). The proporions of servicemen, all serving personnel and poenial recruis wih ELl above and below 15 % are shown in Table 1. Discussion Treadmill esing has been shown o be a reliable mehod of demonsraing increased bronchial labiliy and sandard mehods and paerns of response are described4, 5, 6. The level of exercise chosen was one likely o demonsrae changes in bronchial labiliy under conrolled condiions and o be wihin he capabiliies of apparenly well recruis. Only wo subjecs were unable o complee he proocol, one developing ashma a wo mines, he oher ches pains which prevened furher exercise. We did no adop he pracice of a second period of exercise following bronchodilaor aerosol inhalaion o increase labiliy as we wished o keep he procedure as simple as possible. We consider i imporan ha he FEV 1 and PVC resuls are checked carefully o exclude variable and non-maximum effor oherwise spuriously high labiliy resuls may be obained. In only seven cases were he resuls so inconsisen as o be unimalysable. Published resuls for normal bronchial labiliy have produced resuls higher han hose described here. Resuls will vary wih he mehod used however. Our experience suggess ha individuals wih labiliy well over 20% may only have sympoms during he susained physical aciviy required for miliary raining, and ohers who deny childhood ashma have a hisory of "wheezy bronchiis" if asked. We herefore fel i appropriae o define our own normal range in a group wih no relevan pas hisory and who had compleed basic miliary raining unevenfully. These subjecs were eiher echnicians in he clinical measuremens deparmen or orhopaedic paiens undergoing remedial physioherapy. None experienced any difficuly performing he es.

4 J Carson and C R Winfield We have hus defined a range of normal exercise bronchial labiliy wih a mean of 7.81 and a sandard deviaion (n-i) of A convenional upper limi of normal would be (mean + 2SD) and i would be highly unlikely ha a normal resul would exceed (mean + 3SD). In discussing our resuls we have aken an ELl of over 15 o be abnormal. Labiliy in Ashmaic Subjecs In he group of ashmaic servicemen who could no pass he BFT only 10 (23.8%) had an abnormal resing vialograph. A small number of servicemen in low medical caegory wih chronic persisen wheeze were deliberaely no esed. In conras several individuals in his group had lile or no incapaciy in everyday aciviy and spors including fooball, badminon and squash alhough hey were ofen aware of some wheeze during hese aciviies. Characerisically hese subjecs failed heir BFT during he "Bes Effor" run, ha is afer 6 o 10 minues susained running. Figure 1 shows he disribuion of ELl in his group. The ELl exceeded 20 in 35 subjecs (83.6%) and exceeded 15 in 38 subjecs (90.5 %). Thus in known ashmaic servicemen here is a good correlaion beween an ELl above 15 and failure in he BFT. In he six servicewomen wih ashma who could no pass he BFT all had an ELl above 15 so ha overall 91.7% of 48 service personnel unable o pass he BFT had an ELl of more han 15. (Table 1.) sympoms had developed hree monhs earlier on reurn o UK in November from Hong Kong. He complained of wheeze when no running his habiual 10 o 12 miles daily. His resing FEV! rose from 3.1L o 3.55L (14.5%) on exercise, falling o 2.6L (16.1 %) afer exercise' (ELl 30.6). Clearly some individuals wih ashma can cope wih he demands of exercise despie abnormal labiliy, bu hey are probably excepional. Increased exercise induced bronchial labiiiy is only one aspec of bronchial ashma and will differ in degree beween individuals 2 alhough i has been suggesed ha mos if no all ashmaics will show an abnormal response o an exercise or cold hypervenilaion es if his is severe enough 8, 9. The es which we used a ambien indoor emperaure will no idenify all subjecs wih abnormal bronchial labiliy. Neverheless we feel here is a useful correlaion beween our resuls and abiliy o pass he BFT. Of he oal of 67 ashmaic serving personnel esed 48 had a labiliy of over 15 and of hese 44 (91.7%) could no pass he BFT. In 43 of hem he ELl exceeded 20 and 41 (95.4%) could no pass he BFT. We feel ha hese observaions in service personnel jusify he view ha an individual wih an ELl above 15 is unlikely o mee he army sandard of basic finess. An individual wih an ELl above 20 is highly unlikely o do so. Labiliy in Recruis This group had all been passed fi a pre-service and iniial medical examinaion. Thiry five of hem Table 1 Disribuion of normal and abnormal Exercise LabiIiy Index in groups of ashmaic subjecs GROUP Ashmaic Servicemen who failed BFT All Ashmaic Personnel who failed BFT Ashmaic Servicemen who passed BFT All Ashmaic Personnel who passed BFT Poenial Recruis wih Childhood Ashma and minor sympoms in pas year Poenial Recruis wih Childhood Ashma who denied all sympoms in pas year ELl up o 15 ELl above 15 Toal 4 ( 9.5%) 38 (90.5%) 42 4 ( 8.3%) 44 (91.7%) (75 %) 4 (25 %) (73.7%) 5 (26.3%) (48.3 %) 15 (51.7%) (79.5%) 16 (20.5%) J R Army Med Corps: firs published as /jramc on 1 January Downloaded from hp://jramc.bmj.com/ No all ashmaic personnel however fail heir BFT and hese subjecs had lower labiliies (Figure 2). Of hese servicemen only four (25%) were abnormal by our crieria and only wo had an ELl above 20. Boh hese subjecs had an abnormal resing FEV!. One had a labiliy, enirely a fall of 29.2, despie having passed a BFT six monhs earlier. The oher was a marahon runner aged 38 whose had a pas hisory of ashma and abou half of hese had been referred for specialis opinion. Only wo had been exercise esed, boh by us and boh were normal and remained normal on re-esing. Many of he group were referred wih sympoms which developed on exercise much more srenuous han ha demanded by he BFT, for example 5 o 10 mile runs in bale order. lhree SUbjecs, on 3 April 2019 by gues.

5 18 indicaed in figure 3, only developed sympoms on compleion of such a 10 mile run. Thus he broader spread of resuls wih more normal labiliies is no surprising. The resuls however sugges ha up o 68 % migh have been idenified prior o enlismen if an exercise es had been done prior o he pr\'! service medical examinaion. Labiliy in Poenial Recruis in Remission Of he 108 poenial recruis esed all bu wo claimed o have had only mild childhood sympoms, wih lile or no ime off school, no hospial admission, or prolonged periods of reamen of any sor. All claimed o be in remission and had been considered normal a iniial or pre-service examinaion, being referred in accordance wih Pulheems regulaions. By criical direc quesioning we obained hisorie,> of wheeze, however rivial, in 29 subjecs in he previous year. As shown in figure 4, we found 15 (51.7%) of his group were abnormal. The disribuion of ELl was quie differen in he 78 who denied all sympoms afer close quesioning (figure 5). Neverheless 16 (20.5 %) were abnormal by our crieria. Conclusion A separae analysis of poenial recruis in apparen remission has shown no relaionship beween duraion of remission, aopic hisory, age of subjec, smoking habi and he finding of an ELl above Criical quesioning will reveal some sympoms in a proporion of individuals who claim o be in remission. Neverheless a number of individuals wih a hisory of childhood ashma who appear o be in complee remission, ofen playing spor a school wih no problem, will have an ELl of an order which we feel is unlikely o be compaible wih he performance of miliary raining. Some of he subjecs we considered abnormal had an abnormal resing FEV 1, bu he majoriy were normal a res. We feel herefore ha when recruis wih a pas hisory of ashma are being assessed, hose no found o have ashma afer a careful hisory and resing venilaion ess should undergo a formal exercise es as a subsanial number will prove o be abnormal and unsuiable for service. Acknowledgemens We wish o hank he echnicians in he clinical measuremen deparmen who carried ou mos of he exercise ess. Exercise Tesing in Servicemen wih Ashma and is applicaion o he assessmen of Poenial Recruis REFERENCES 1 TREFOR JONES R HAND JONES R S. Venilaory capaciy in young aduls wih a hisory of ashma in childhood. Bri Med J 1966; 11: MARTIN A J, LANDAU L I AND PHELAN P D. Lung funcion in young aduls who had ashma in childhood. Am Rev Respir Dis 1980; 122: PULHEEMS. A Join Service Sysem of Medical Classificaion. 1976; 0420(b). 4 ANDERSON S D, SILVERMAN M, KONIG P AND GODFREY S. Exercise Induced Ashma. Bri J Dis Ches 1975; 69: CROPP G J E. The Exercise Provocaion Tes. Sandardisaion of procedures and evaluaion of response. J Allergy Clin Immunol 1979; 6: Sudy Group on Exercise Challenge, American Academy of Allergy. Guidelines for he mehodology of exercise challenge esing of ashmaics. J Allergy Clin Immunol 1979; 6: BURR M L, ELDRIDGE B A AND BORYSIEWICZ L K. Peak expiraory flow raes before and afer exercise in school children. Arch Dis Childh 1974; 49: HAYNES R L, IGRAM R HAND McFADDEN E R. An assessmen of he pulmonary responses o ~xercise. in.ashma and an analysis of he facors InfluenCIng I. Am Rev Respir Dis 1976; 114: DEAL E C, McFADDEN E R, INGRAM R H, BRESLIN F J ~ND JAEGER J J. Airways responsiveness o cold air. and hyperpnoea in normal subjecs and in hose Wih hay fever and ashma. Am Rev Respir Dis 1980; 121: WINFIELD C AND CARSON J. Bronchial labiliy in ashmaics in remission - In preparaion.