DECEMBER 1980 P H Y S I O T H E R A P Y 9 3 CH ES T A S S ES S M EN T AND S I M P L E L U N G FU N C TIO N T ES TS C. P . R O D S E T H , B.Sc. (P h y s io th e ra p y ) (W itw a te rs ra n d ), M .Sc. (S tra th c ly d e ), M .C .S .P ., D ip .T .P .* S U M M A R Y T h e m a in e le m e n ts o f a c h e s t a ssessm e n t are ou tlin e d . E le m e n ta r y m e a su r e m e n ts w h ich s h o u ld be ta ke n by p h y sio th e ra p ists are d escribed. S im p le lu n g fu n c tio n tests w h ich are w ith in the ca p a b ility o f p h y s io th e r a p is ts w h o are closely c o n c e rn e d w ith c h e s t p a tie n ts are e x ­ p la in e d in s o m e d e ta il. T h e te s ts c o n c e rn e d are: P e a k E x p ira to ry F lo w R a te , F o rc e d V ita l C ap a c ity , F o rc e d E x p ira to ry V o lu m e in 1 sec. a n d th e ratio F o r c e d E x p i­ ratory V o lu m e in 1 se c ./F o r c e d V ita l C a p a c ity as a percentage. F o u r o f the m o r e a d v a n c e d te s ts a n d their u n d e rly in g c o n c e p ts w h ich are m o r e the d o m a in o f sp e c ia l p u lm o n a ry testin g la b o ra to ries are b rie fly described. A th o ro u g h a sse ssm e n t o f th e p a tie n t is a n e ssential .^ re q u ire m e n t p r io r to d e cid in g o n tre a tm e n t m o d alitie s a n d in o r d e r to m o n ito r p ro g ress. T h e classical c h e s t a sse ssm e n t c om prises: Su bjective e xam in ation — e lic itin g th e s y m p to m s b y ta k in g th e h isto ry a n d a sk in g th e p a tie n t to d e sc rib e th e p ro b le m . O bjective exam in ation — e lic itin g th e sig n s in th e tim e -h o n o u re d se q u e n c e of: o b s e rv a tio n , p a lp a tio n , p e r ­ c u ssio n , a u s c u lta tio n a n d sp e c ia l in v e s tig a tio n s. Interpretation o f the findings b y c o rre la tin g th e re su lts o f th e e x a m in a tio n s a n d c o m p a rin g th e m w ith n o rm a l values. O B JE C T IV E E X A M I N A T I O N O bservation T h e s h a p e o f th e c h e s t to g e th e r w ith th e ra te , rh y th m a n d p a tte rn o f c h e s t wall m o v e m e n t a re o b se rv e d . Palpation P la c in g th e h a n d s on th e c h e s t u su a lly c o n firm s th e p a tte rn o f b re a th in g p re v io u s ly o b se rv ed a n d m a y re v ea l th e p re se n c e o f se c re tio n s b y th e v ib ra tio n s p ro d u c e d w h e n a ir m o v es o v e r th e m . P a lp a tio n allo w s th e o b ­ s e rv e r to g a in a g e n e ra l id e a o f th e lo c a tio n o f such se c re tio n s. p e r c u s s io n T a p p in g th e d o rs u m o f th e m id d le p h a la n x o f th e m id d le finger o f th e n o n - d o m in a n t h a n d p la c e d flat on th e c h e s t wall w ith th e tip o f th e m id d le fin g er o f th e d o m in a n t h a n d . T h e q u a lity o f th e v ib ra tio n s so p r o ­ d u c e d is p e rc e iv e d b o th w ith th e re s t o f th e h a n d a n d y s o “ n d - T h 's re v ea ls e ith e r a n o rm a l re so n a n c e in- resonancet as w i‘h a c o lla p se d lu n g o r severe ° r rd^ ' re“sed reso n a n c e (d u lln e ss) as w ith c o n s o lid a tio n o f th e lu n g o r p le u ra l th ic k e n in g . A u scu ltation I n te r p r e ta tio n o f th e s o u n d s h e a rd w ith a s te th o - riso n m o ) 1' ' ^ W‘th th e p re v io u s issu e rP h y s io th e ra p y , UnT- y o f C a P e T o w n a n d G ro o te S c h u u r H o s p ita l. O P S O M M IN G D ie b e la n g r ik ste p u n te van ’n resp ira to rie se e ya lu er- ing w o rd a a n gedui. E le m e n te r e m a te w at d e u r die fis io - te r a p e u t g e n e e m b e h o o r t te w o rd , w o r d b e s k r y f. E e n - vo u d ig e lo n g fu n k s ie to e ts e , w at d e u r fis io te ra p e u te , wat ervare is in d ie b e h a n d e lin g van resp ira to rie se p asiente, u itg e v o e r k an w o rd , w o rd in re d e lik e d e ta il v erd u id e lik . D ie b e tr o k k e to etse is: P ie k E k s p ir a to r ie se V lo e isn e l- heid, G e fo rse e r d e V ita le K a p a site it, G e fo rse e r d e E k s p i­ ratoriese V o lu m e in 1 se k o n d e en die v e r h o u d in g van G e fo rse e rd e E k s p ir a to r ie se V o lu m e in I s e k o n d e to t G e fo rse e rd e V ita le K a p a site it a a n g e d u i as ’n p ersentasie. N o g v ier g e v o r d e rd e to etse en h u l o n d e rlig g e n d e k o n - septe, w a t v e r k ie s lik d e u r spesiale p u lm o n a le to etsla b o - ra to riu m s u itg e v o e r b e h o o r t te w ord, w o rd k o r tlik s b e sk ry f. O th e r sp e c ia l in v e s tig a tio n s a n d m e a s u re m e n ts m a y be classified as e le m e n ta ry , sim p le a n d a d v a n c e d . E L E M E N T A R Y S P E C IA L IN V E S T IG A T IO N S A N D M E A S U R E M E N T S T h e o n ly e q u ip m e n t re q u ire d fo r th e e le m e n ta ry m e a s u re m e n ts is a ta p e -m e a s u re a n d a w a tc h w ith a sw eep se c o n d h a n d . C hest E xpan sion T h e c irc u m fe re n c e o f th e c h e s t a t th r e e lev els is ta k e n re stin g , a f te r fu ll e x p ira tio n a n d th e n a f te r full in s p ira tio n . T h e b e st o f th re e re a d in g s is ta k e n a n d r e ­ c o rd e d . T h e levels a re: a x illa (a p p ro x im a te ly 4 tfi rib); x ip h o id p ro c ess; te n th c o stal c a rtila g e (lo w e st p o in t o f c o m p le te rib cage). T h e d iffe re n c e b e tw e e n th e fu ll e x ­ p ira to ry a n d fu ll in s p ira to ry v a lu e s is th e e x p a n s io n . E xercise T olerance S e v e re s h o rtn e s s o f b r e a th w o u ld h a v e b e e n n o tic e d d u rin g th e O b s e rv a tio n se c tio n o f th e a sse ss m e n t. T o m e a s u re e x erc ise to le ra n c e m o re o b je c tiv e ly , a n e x e r­ cise lo a d is im p o s e d o n th e p a tie n t, th e r e s p ira to ry a n d p u lse ra te s b e in g n o te d b e fo re a n d fo r tw o m in u te s a f te r c o m p le tio n o f th e e xercise. R e s p ir a to r y rate. T a k e n f o r 1 m in u te b e fo re exercise a n d a t 2 m in u te s a f te r e xercise. I t s h o u ld h a v e re tu r n e d to th e re stin g v a lu e by th e n . P ulse ratio. R e s tin g ra te n o te d b e fo re e x e rc is e a n d th e n f o r 2 m in s. a f te r e xercise. D iv id e th e n u m b e r o f b e a ts in th e 2 m ins. a f te r e x e rc is e b y th e re stin g ra te . N o rm a l r a tio is less th a n 2,5. A n y a p p r o p ria te e x e rc is e m a y b e used, su c h a s th e H a r v a r d s te p -te s t o r so m e f u n c tio n a l a c tiv ity su c h as g e ttin g o u t o f b e d o r ta k in g a s h o r t w alk. In a d d itio n , if th e p a tie n t is a m b u la n t, th e g re a te s t d is ta n c e h e c a n c o m fo rta b ly c o v e r a n d th e tim e ta k e n to d o so s h o u ld b e n o te d a n d c h e c k e d fro m tim e to tim e. SIM P L E L U N G F U N C T IO N T E ST S T h e sim p le lu n g f u n c tio n te s ts w h ic h w ill b e d e a lt w ith in so m e d e ta il h e re a re w ith in th e sc o p e o f a n y p h y s io th e ra p is t in v o lv e d in tre a tin g c h e s t c o n d itio n s. T h e y a re m e a s u re m e n t a n d in te r p r e ta tio n of: • P e a k E x p ira to ry F lo w R a te (P e a k F lo w o r P E F R ) • V ital C a p a c ity (V C ) a n d F o rc e d V ita l C a p a c ity R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) 94 F I S I O T E R A P I E DESEMBER 1980 (FV G ). • F o rc e d E x p ir a to ry V o lu m e in 1 sec. ( F E V ,l0 a lso w ritte n F E V ,). • D e riv e d f r o m t h e la s t tw o , th e r a tio o f F E V i,„ /F V C o r F E V , / F V C T h e s e te s ts in v o lv e s p iro m e try (m e a s u rin g o f b re a th ) a n d th e r e f o r e , a n o r m a l s p iro g ra m is p re s e n te d as an in tr o d u c tio n (fig. 1). 100 7 5 5 0 a eI— F ig . 1. A spirogram o f a su bject breathing n or­ m ally, then taking a fu ll d eep breath, breathing ou t fu lly and then returning to norm al breathing. T V — tidal vo lu m e , E R V — expiratory reserve v o lu m e , IR V — inspiratory reserve v o lu m e , V C — vital cap acity, R V — residual v o lu m e , F R C — fu n ctio n a l residual cap acity. T h e tidal v olu m e is b etw een 0,5 and 0,6 litres. A s p iro g ra m o f a sin g le fu ll (fo rc e d ) e x p ir a tio n fro m fu ll in s p ira tio n to c o m p le te v o lu n ta ry e x p ir a tio n is a ls o sh o w n (fig. 2). In th is c ase, th e v o lu m e o f e x p ire d a ir is p lo tte d a g a in s t tim e in se c o n d s as th is is h o w th e c o m m o n ly u se d c lin ic a l s p iro m e te rs p r e s e n t th e re su lt. cn a . I— < Time in sec F ig . 2. Spirogram o f a sin g le , fu ll, forced exp ira­ tion sh o w in g F E V , and F V C . P ea k E xpiratory F lo w R a te (P E F R ) T h is is a flo w rate (i.e. v o lu m e p e r u n it tim e). I t is th e fa s te s t in s ta n ta n e o u s flow ra te a c h ie v e d d u rin g e x ­ p lo siv e ly fo rc e d e x p ir a tio n a f te r fu ll in s p ira tio n , irre s ­ p e c tiv e o f e x a c tly w h e n d u rin g th e e x p ira tio n it is a c h ie v e d . H o w e v e r, if h ig h sp e e d tu rb u le n c e o c cu rs, in d ic a te d by s trid o r, a lo w e r re a d in g is o b ta in e d . I t is a n a lo g o u s to a n a n e m o m e te r w h ic h m e a su re s w ind sp e e d d u rin g th e n ig h t, th e p o in te r r e m a in in g a t th e sp e e d o f th e s tro n g e s t g u s t o f w in d w h e n e v e r it o c ­ c u rre d . M e a s u r e m e n t P e a k e x p ira to ry flow ra te m a y b e re a d off a s p iro ­ g ra m w h e re it c o rre s p o n d s to th e s te e p e s t p a r t o f th e c u rv e , i.e. w h e n th e r e is th e g re a te s t v o lu m e o f a ir e x p ire d in th e s h o r te s t tim e . A s th is p o in t m a y be d ifficult to p e rc e iv e o n th e g ra p h b y eye, th e slo p e is u su a lly re a d off as th e tim e ta k e n to e x p ire a single litre o f a ir n e a r th e s ta r t o f th e e x p ira tio n a n d th e n c o n v e rte d to flow r a te in l it r e s /m in . o r litr e s /s e c . In th e c ase o f th e V ita lo g ra p h S in g le B re a th S p ir o m e te r , (F ig. 3) th e slo p e o f a lin e jo in in g 0 ,2 litre s to 1,2 litres^ o f a ir e x p ire d is re a d , u sin g a p la s tic p r o tr a c to r p re ­ c a lib ra te d to re a d flow r a te d ire c tly . M o re u s u a lly , a specific p e a k f lo w m e te r is used. P r o b a b ly th e b e st k n o w n ty p e is th e W r ig h t’s P ea k F lo w M e te r (fig. 4). T h is in s tru m e n t is 14 cm in d ia ­ m e te r a n d 6 c m d e e p . I t m u s t be h e ld v e rtic a lly w ith th e d ial fa c in g t o th e p a ti e n t’s rig h t. In th is in s tru m e n t, th e n e e d le sh o w s th e p e a k flow ra te m a in ta in e d f o r a p e rio d o f 0,01 sec. A lth o u g h th e “ b ig ” W r ig h t’s has b e en th e s ta n d a r d p e a k flow m e te r f o r m a n y y e a rs, it is a s o m e w h a t d e lic a te in s tr u m e n t w ith fine m o v in g p a rts . In th e p a s t few y e a rs, a W r ig h t’s M i n i P ea k F lo w M e te r (fig. 4) h a s b e en in tro d u c e d . T h is is a p la s ­ tic c y lin d e r 13 cm lo n g a n d 4,3 cm in d ia m e te r. It h a s b e e n sh o w n to h a v e g o o d re p ro d u c ib ility o f re su lts a n d a h ig h c o rre la tio n o v e r th e w h o le ra n g e w ith th e “ b ig ” W r ig h t’s m e te r (M .R .C .). V ita lo g ra p h h a v e a lso p ro d u c e d a s im ila r sim p le in s tr u m e n t c a lle d th e V ita ­ lo g ra p h P u lm o n a r y M o n it o r w h o se re a d in g s a re c o r re ­ la te d to p e a k e x p ira to ry flow ra te a n d fo rc e d e x p ira to ry v o lu m e in 1 sec. T h e b e s t o f th r e e re a d in g s is ta k e n . In te r p re ta tio n T h e P E F R o b ta in e d fo r a p a r ti c u la r p a tie n t m u s t be c o m p a re d w ith th e p re d ic te d v a lu e f o r a s u b je c t o f th e sa m e sex, a g e a n d h e ig h t, e.g. fe m a le , 30 y e a rs a n d 160 cm (5 '3 "), n o r m a l P E F R is 474 litre s /m in . A^ re d u c e d v a lu e is g e n e ra lly ta k e n as a n in d ic a tio n o f a ir ­ w ays n a rro w in g . H o w e v e r, it is n o t re g a rd e d as very re lia b le , e sp e c ia lly fo r p a tie n ts su ffe rin g fro m a c u te b ro n c h o s p a s m , as th e te s t re q u ire s c o n s id e ra b le p a tie n t effo rt a n d c o -o p e ra tio n a n d , in su c h a c u te cases, it o f te n a g g ra v a te s th e b ro n c h o s p a s m . T h e p a tie n t soon le a rn s to a v o id th is by “ n o t try in g so h a r d ” . In tu rn , th is p ro d u c e s a lo w e r th a n e x p e c te d r e a d in g in a p a tie n t w h o is o b v io u sly c lin ic a lly im p ro v e d . T h e te s t does, h o w e v e r, h a v e g r e a t use in m o n ito rin g th e s ta le of a irw a y s n a rro w in g in c h ro n ic cases. P E F R re c o rd in g s ta k e n a n d re c o rd e d th r e e tim e s d a ily by th e p a tie n t h e lp in b o th th e c la ss ific a tio n o f th e d ise ase a n d in d e c id in g o n o p tim a l m a n a g e m e n t (T u rn e r-W a rw ic k , 1977). T h is t e c h n iq u e is no w in w id e u se a m o n g b o th g e n e ra l p r a c titio n e r s a n d r e s p ira to ry p h y sic ia n s. P h y s io ­ th e r a p is ts c o n c e rn e d w ith su c h p a tie n ts s h o u ld b e f a m i­ lia r w ith th e c o n c e p t. W h e n m a k in g v o lu m e m e a s u re m e n ts , th e v o lu m e s re c o rd e d b y th e s p ir o m e te r a re a t a m b ie n t te m p e ra tu r e a n d p re s s u re , a n d s a tu r a te d w ith w a te r v a p o u r (A T P S ). I f g r e a t a c c u ra c y is re q u ire d , th e s e s h o u ld b e c o n v e rte d R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) DECEMBER 1980 P H Y S I O T H E R A P Y 95 Fig. 3. A V ita lo g ra p h sin g le -b re a th , w c d g e-b e llo w s, dry S p iro m ete r. to b o d y t e m p e r a t u r e a n d b a r o m e t r i c p r e s s u r e , a l s o s a t u r a t e d w i t h w a t e r v a p o u r ( B T P S ) . T h e V i t a l o g i a p h g r ap hs h a v e b o t h v o l u m e s c a l e s v a li d loi m o s t test co nd it io ns. V ital C ap acity (V C ) a n d F o rc e d V ital C a p a c ity (F V C ) Both o f th e s e a r e t h e m a x i m u m v o l u m e o f a i r ( m e a ­ sured in litres) w h i c h c a n be e x p e l l e d a l t e r m a x i m u m i ns pi ra ti on . T h e d i f f e r e n c e is t h a t , f o r V C . t h e t i m e t ak en f o r e x h a l a t i o n is n o t c o n s i d e r e d , w h e r e a s , f o r F V C , th e b r e a t h m u s t be e x p e l l e d as r a p i d l y a n d c o m ­ pletely as p os s ib le . A s a test o f p u l m o n a r y f u n c t i o n , it is us u a l ly t h e F V C w h i c h is m e a s u r e d . M e a s u r e m e n t F V C is m e a s u r e d by a s p i r o m e t e r in t h e cl in ic al sci ting, u su a lly t h e d r y b e l l o w s t y p e ( V i w l o x r a p h ) . A s m a ll i n s t r u m e n t , t h e W r ig lil’s R e s p i r o m e t e r is a v a i l a b l e w'hich is s u i t a b l e f o r m e a s u r i n g v ital c a p a c i t y a n d m i n u t e vjj lu me (tota l v o l u m e o f a i r e x h a l e d in o n e m i n u t e , i.e. i • i vol. x r e s p i r a t o r y r at e) a t e x p i r a t o r y flow r a t e s bt rtv e en 3,0 l i t r e s / m i n . a n d 3 0 0 l i t r e s / m i n . B e lo w 3.0 l i t r e s / m i n . it d o e s n o t r e g i s t e r a n d a b o v e 3 0 0 l i l i e s / min. t he d e l i c a t e m e c h a n i s m m a y be d a m a g e d , t h e r e ­ fore, it is n o t s u i t a b l e f o r u s e w i t h f a i r l y h e a l t h y a d u l t s w h o c a n p r o d u c e P E F R s o f u p to 6 0 0 l i t r e s / min. ( D a y k i n e t ul. 1978). T h e t e c h n i q u e is t o i n s t r u c t t h e s u b j e c t ( p r e f e r a b l y st a n d in g ) to b r e a t h e o u t . t h e n t o t a k e as d e e p a b r e a t h as po ssible, pu t t h e m o u t h p i e c e i n t o h is m o u t h , to b l o w ou t as h a r d as h e c a n a n d t o c a r r y o n u nt i l he has a b s o l u t e l y n o b r e a t h left, b e i n g v e r b a l l y e n c o u r a g e d all t h e l i m e by th e o p e r a t o r . T h e be s t o f t h r e e p e r ­ f o r m a n c e s is t a k e n . In te r p r e ta tio n N o r m a l v a l u e s o f F V C v a r y d i r e c t l y w i t h h e i g h t , in ver sel y w it h a g e a n d a r e l o w e r in f e m a l e s . T h e p r e ­ d ic te d n o r m a l v a l u e s f o r a n i n d i v i d u a l s h o u l d be d e t e r ­ m i n e d f r o m a n o m o g r a m b e f o r e i n t e r p r e t i n g t he results. A l so , f o r p a t i e n t s w it h o b s t r u c t i v e a i r w a y s o r re st r i c t i v e l u n g d i s e a s e , t h e v a l u e o f F V C s h o u l d be c o m p a r e d w i t h t h a t o f t h e f o r c e d e x p i r a t o r y v o l u m e in 1 sec. If p os s ib le , it s h o u l d a l s o be c o m p a r e d w it h F ig. 4. W rig h t's P e a k F lo w M e te r (left) a n d W rig h t's M in i P e a k Flow M e te r (rig h t). to t a l Inns; c a p a c ity b u t thi s is a n a d v a n c e d p u l m o n a r y f u n c t i o n test. H o w e v e r . F V C is a n i m p o r t a n t test Lor p a t i e n t s w h o h a v e e i t h e r a t h o r a c i c d e l o r m i t y s u c h as k y p h o s c o l i o s i s o r a n k y l o s i n g s p o n d y l i t i s o r w e a k n e s s ol th e r e s p i r a t o r y m u s c l e s . P a i n o r m e c h a n i c a l i n t e r f e r ­ e n c e w i t h b r e a t h i n g , e.g. f r a c t u r e d rib s, c a n a l s o r e ­ d u c e t h e F V C . A m a r k e d l y r e d u c e d F V C i n d i c a t e s a g r e a t e r d a n g e r ol c h e s t i n f e c t i o n o r p o s t - o p e r a t i v e ch e s t c o m p l i c a t i o n s a n d a r e d u c e d a b i l i t y to c o p e w i t h it. It ca n a l e r t t h e t e a m t o a p o s s i b l e n e e d t o m e c h a n i c a l l y v e n t i l a t e a p a t i e n t at risk . In a n a d u l t , a n F V C f a l l in g , o v e r l i m e , t o w a r d s 1 li t re is r e g a r d e d as life t h r e a t e n ­ ing. In t h e a b s e n c e o f a s p i r o m e t e r , a r o u g h r u l e o f t h u m b w h i c h m a y b e h e l p f u l is t o as k t h e p a t i e n t lo t a k e as d e e p a b r e a t h as p o s s i b l e , t h e n t o c o u n t s t e a d i l y o u t a l o u d u nt i l t h e y r u n o u t o f b r e a t h . A n i n a b i l i t y t o r e a c h a b o v e t w e n t y s u g g e s t s a d a n g e r o u s l y low V C . F o rc e d E x p ira to ry V o lu m e in I see. (F liV ,.,, o r F E V ,) T h i s is t h e v o l u m e ( m e a s u r e d in litres) w h i c h is e x ­ p ir ed d u r i n g t h e first s e c o n d ol a f o r c e d e x p i r a t i o n . S o m e t i m e s t h e v o l u m e m a y be m e a s u r e d o v e r a d i f ­ f e r e n t p e r i o d s u c h a s t h e first 0, 5 . 2,0 o r 3 ,0 s e c b u t th e c o m m o n m e a s u r e m e n t is t h a t o v e r 1,0 sec. M e a s u r e m e n t T h e F E V , i.s m o s t e a s i l y r e a d off a s i n g l e f o r c e d e x ­ p i r a t i o n s p i r o g r a m s u c h as t h a t o b t a i n e d w i t h a V i t a - l o g r a p h a n d is t a k e n f r o m t h e b es t o f t h e t h r e e F V C r e c o r d i n g s . I n t e r p r e t a t io n F E V , , as w it h F V C . v a r i e s d i r e c t l y w i t h h e i g h t , i n ­ v er se l y w i t h a g e a n d is l o w e r in f e m a l e s . T h e p r e d i c t e d n o r m a l v a l u e f o r t h e s u b j e c t s h o u l d be a s c e r t a i n e d . S i n c e t h e F E V , is a m e a s u r e o f v o l u m e e x p i r e d d u r i n g a fixed u n i t o f t i m e , it is a c t u a l l y a m e a s u r e ol flow, t o be p r e c i s e t h e f l o w - r e s i s t a n c e in t h e a i r w a y s g r e a t e r t h a n 2 m m in d i a m e t e r . A r e d u c e d F E V , i n d i ­ ca t e s i n c r e a s e d r e s i s t a n c e o f t h e a i r w a y s as f o u n d in b o t h o b s t r u c t i v e a i r w a y s d i s e a s e ( c h r o n i c b r o n c h i t i s , e m p h y s e m a , c h r o n i c a s t h m a , etc.) a n d in r e s t r i c t i v e lu n g d i s e a s e ( p u l m o n a r y f ib ro s is o r o e d e m a ) . P r o b a b l y R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) its m o s t i m p o r ta n t a p p lic a tio n , h o w e v e r, is in c o rre ­ la tin g i t to th e p a ti e n t’s F V C . R a tio o f F orced Expiratory V o lu m e in 1 sec. to F orced V ital C ap acity (F E V ,/F V C ) T h is ra tio , e x p re sse d as a p e rc e n ta g e , s h o u ld b e d e ­ riv e d fro m th e s a m e b r e a th , i.e. th e p e rc e n ta g e o f th e to ta l e x h a la tio n w h ic h th e s u b je c t c a n b re a th e o u t in th e first se c o n d . M e a s u r e m e n t T h is is a c a lc u la tio n b ased o n th e F E V i a n d F V C of a sin g le e x h a la tio n u s u a lly m e a s u re d o n a single b re a th s p iro m e te r. I t is e x p re sse d as a p e rc e n ta g e . S o m e a u th o ­ ritie s m a y a ls o u se th e F E V o v e r a p e rio d o th e r th a n th e first se c o n d . T h is w o u ld a lw a y s b e d e n o te d by th e su b s c rip t to F E V . In te r p re ta tio n T h e n o r m a l v a lu e o f F E V i / F V C is 8 0 % w ith a ra n g e fro m 7 5 - 85'% , A re d u c e d v a lu e in d ic a te s a ir ­ w ay s n a rro w in g o f t h e o b s tru c tiv e ty p e. T h e r a tio is o f te n n o r m a l f o r p a tie n ts w ith re s tric tiv e d ise a s e as b o th re a d in g s a re re d u c e d in p ro p o r tio n to e a c h o th e r. A D V A N C E D L U N G F U N C T IO N T E ST S A N D C O N C E P T S T h e s e a r e n u m e ro u s a n d o f a s o p h is tic a tio n lim ite d o n ly b y th e re so u rc e s a n d in g e n u ity o f th e la b o ra to ry c o n c e rn e d . B o th th e ir p e r fo r m a n c e a n d in te rp re ta tio n a re b e y o n d t h e sc o p e o f m o s t p h y s io th e ra p is ts ; h o w ­ e v e r, a fe w re m a rk s a b o u t so m e o f th e m o re c o m m o n a d v a n c e d te s ts a n d . re la te d c o n c e p ts m a y b e h e lp fu l. B lo o d G as A n alysis O fte n c o m m o n ly r e fe r r e d to as “ th e A s tr u p ” , th is is a m e a s u r e m e n t o f th e p a r ti a l p re s s u re o f o x y g e n a n d c a rb o n d io x id e in th e a r te r ia l b lo o d . T h e norm ail v a lu e s, i n . S I u n its , a re P a O j = 9,5 — 13,9 k ilo p a sc a ls (k P a . l k P a = 7,5 m m H g ), P a C O , = 4,1 - 6,1 k P a . F r o m th e s e tw o, th e a c id i ty /a l k a li n ity o f th e b lo o d c a n b e c a lc u la te d . N o rm a l a r te r ia l p H is 7,4 (ra n g e 7,38 — 7,4 6 ). In th r e a te n in g r e s p ira to ry fa ilu re , t h e P a 0 5 falls, P a C O - rise s a n d p H fa lls (b e co m es m o re acid). F lo w /V o lu m e L oop T h e su b je c t p e rfo rm s a fo rc e d in s p ira tio n fo llo w ed by a fo rc e d e x p ira tio n in to a n in s tr u m e n t w h ic h re c o rd s b o th th e flo w -rate s a c h ie v e d a n d th e v o lu m e s o f gas m o v e d a n d a u to m a tic a lly p lo ts th e flo w -rate a g a in s t th e v o lu m e . A s it is a c losed sy ste m , a c lo sed lo o p is o b ­ ta in e d . T h is is a c o m p a ra tiv e ly s im p le te s t a n d y et yield s v a lu a b le in f o r m a tio n w h ic h c a n b e u se d to c h a ra c te ris e a n d d iffe re n tia te th e v a rio u s ty p es o f a ir ­ w ay s d y sfu n c tio n (R u d n ic k e t a t , 1980). V e n tila tio n /P e r fu sio n R atio F o r s a tis fa c to ry lu n g fu n c tio n , n o t o n ly m u s t a d e ­ q u a te v o lu m e s o f a ir b e v e n tila te d th ro u g h th e lungs, b u t th e a ir m u s t b e in c o n ta c t, th ro u g h th e a lv e o la r m e m b ra n e , w ith a d e q u a te v o lu m e s o f b lo o d p e rfu sin g th e lu n g . T h e v e n til a ti o n /p e r f u s io n ra tio v a rie s in d if­ fe re n t re g io n s o f th e lu n g s d e p e n d in g on p o s tu re . O v e r­ a ll i t is a p p ro x im a te ly 1 : 1 a t 5 litr e s /m i n . e a c h . I n th e e r e c t p o s tu re , it is g r e a te r th a n 1 in th e a p ic e s a n d less th a n 1 in th e b a se s. A se rio u s d e v ia tio n re su lts in u n s a tis fa c to ry g a s t r a n s f e r b e tw e e n th e a ir a n d b lo o d 96 DESEMBER 1980 le a d in g to h y p o x ia a n d h y p e rc a p n ia (raised P a C o 2). C om p liance T h is te rm m a y b e a p p lie d to th e c h e s t w all o r th e lu n g s o r th e c o m b in e d sy ste m . I t is d e fin e d as “ the c h a n g e in v o lu m e p e r u n it c h a n g e in p r e s s u r e ” . T h u s “ stiff lu n g s” o r a n im m o b ile c h e s t w all (o r b o th ) o n ly a lt e r slig h tly in v o lu m e fo r a u n it c h a n g e o f p re ssu re a n d th e re fo re h a v e lo w c o m p lia n c e. A series o f v a lu e s is a lw ay s ta k e n , d e p e n d in g o n th e te c h n iq u e u se d , to p r o d u c e a v o lu m e /p r e s s u r e c u rv e w h ic h is th e n in te r ­ p re te d . M e a s u re m e n ts o f lu n g c o m p lia n c e a r e p a rtic u ­ la rly im p o r ta n t in ju d g in g th e p re ssu re s re q u ire d fo r a rtific ia l v e n tila tio n in p a tie n ts w ith stiff lu n g s su c h as fo llo w in g P a r a q u a t p o iso n in g . F u r th e r in fo r m a tio n o n a d v a n c e d lu n g fu n c tio n tests is g iv en by th e a p p r o p ria te tex ts m e n tio n e d in th e B ib lio g ra p h y . C O N C L U S IO N S c ien tific a n d m e d ic a l k n o w le d g e in th e fields p t r e s p ira to ry p h y sio lo g y a n d p a th o lo g y is e x p a n d in g L th e tim e . In o r d e r to re ta in c re d ib ility as a n im p o r ­ t a n t m e m b e r o f th e tr e a tm e n t te a m , it b e h o v e s th e c o n c e rn e d p h y s io th e ra p is t to b e a m a s te r o f c h e s t a s ­ s e ss m e n t in c lu d in g th e e le m e n ta ry m e a s u re m e n ts , to be c o m p e te n t a t c a rry in g o u t a n d k n o w in g th e sig n ific a n ce o f th e sim p le lu n g fu n c tio n te s ts a n d to b e fa m ilia r w ith th e a d v a n c e d tests. R eferen ces D a y k in , A . P ., N u n n , G . F . a n d W rig h t, B. M . (1978). T h e m e a s u re m e n t o f v ita l c a p a c ity a n d m in u te v o lu m e w ith th e W rig h t R e sp iro m e te r. B rit. J. Dis. C hest, 72, 333 - 335. M o rris o n , S. C . (1980). A u s c u lta tio n o f th e c hest. S .A . J. o f P h y s io th e r. 36, 66 - 69. M .R .C . P n e u m o c o n io s is U n it, L la n d o u g h , U .K . Q u o te d in “ N o te s f o r th e D o c to r. M in i-W rig h t’s P e a k F lo w M e te r ” d is trib u te d f o r C le m e n t C la rk e In te rn a tio n a l L td ., by A l l e n '& H a n b u r y , W ad e v ille, T ra n s v a a l. R u d n ic k , H . L ., L o o ts , J. M ., T h e ro n , J. J., K e r, J. A., a n d M e y e r B. J. (1980). T h e flow v o lu m e c u rv e as a d ia g n o s tic to o l. 5. A fr . M e d . J., 58, 273 - 276. T u m e r-W a rw ic k , M . (1977). O n o b se rv in g p a tte rn s of a irflo w o b s tru c tio n in c h ro n ic a sth m a . B rit. J. D is. C hest, 71, 73 - 86. B ibliography C a p e l, L. H . (1979). A u se o f lu n g f u n c tio n stu d ies, E d . D o w n ie , P . A . in: C a s h ’s T e x tb o o k o f C h e st, H e a r t a n d V a s c u la r D is o rd e rs f o r P h y s io th e ra p is ts , F a b e r a n d F a b e r, L o n d o n , pp. 358 - 373. C h e rn ia k , R . M . (1977). P u lm o n a r y F u n c tio n T es tin g , 1st E d ., S a u n d e rs , P h ila d e lp h ia . L u c k in g , M . T . (1966). T h e u s e o f v e n tila to r y fu n c tio n tests in p h y s io th e ra p y . P h y s io th e r. 52, 420 - 424. P a rry , A . (1980). P h y s io th e ra p y A sse ssm e n t, 1st E d., C ro o m H e lm , L o n d o n . R u p p e l, G . (1979). M a n u a l o f P u lm o n a r y F u n c tio n T e s t­ ing, 2n d E d ., M o s b y , St. L ouis. Spriggs, E. A . (1978). T h e h is to ry o f s p iro m e try . Brit. J. D is. C h e st 72, 165 -1 8 0 . W e s t, J .B. (1977). P u lm o n a ry P a th o p h y s io lo g y , 1st E d ., W illia m s a n d W ilk in s, B a ltim o re . I b id (1979). R e s p ira to ry P h y s io lo g y , 2 nd E d ., W illia m s a n d W ilk in s, B a ltim o re . F I S I O T E R A P I E R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. )