o c c u r T h e in te r e s tin g th in g is t h a t a ll th e s e a b n o r m a litie s c a n r e tu r n to n o r m a l if th e p a t i e n t lo se s th e e x c e ss w e ig h t. H y p o v e n tila tio n S yn d ro m e: 1 P ic k w ic k ia n s y n d r o m e . T h is is v e ry s im ila r t o th e p a t t e r n p ro d u c e d b y g ro s s o b e s ity a n d , in f a c t, g ro s s o b e s ity is o n e o f th e c h a r a c te r is tic s o f th is s y n d r o m e . I n a d d itio n th e re is m a r k e d s o m n ile n c e , c y a n o s is a n d p o ly c y th a e m ia . T h e s y n d r o m e d e riv e s its n a m e , o f c o u r s e , f ro m th e fa t b o y o f ‘T h e P ic k w ic k P a p e r s ’ (C h a r le s D ic k e n s). 2 D a m a g e to th e r e s p ir a to r y c e n tr e . T h is m a y o c c u r a s a re su lt o f e n c e p h a litis a n d th e s e p a tie n ts m a y p re s e n t w ith n o p u lm o n a r y d is a b ility b u t w ith p o ly c y th a e m ia a n d c y a n o sis. O n c e a g a in , th e c h a r a c te r is tic fin d in g is t h a t o f a lv e o la r h y p o v e n tila tio n . P o ly c y th a e m ia : T h e se p a tie n ts a r e f re q u e n tly b r o u g h t fo r p u lm o n a r y f u n c tio n te s ts w ith a view to d e c id in g w h e th e r th is is a p r im a ry d e v ia tio n o f th e b o n e m a r r o w o r s e c o n d a r y to p u lm o n a r y p a th o lo g y . F o r t h e m o s t p a r t, a r t e r i a l o x y g e n levels a r e n o rm a l in p r im a r y p o ly c y th a e m ia a n d c o n s id e ra b ly re d u c e d in p o ly c y th a e m ia d u e t o p u l m o n a r y p a th o lo g y . A fu ll ra n g e o f p u l m o n a r y f u n c tio n te s ts f r e q u e n tly p r o v id e s th e a n s w e r in th is ty p e o f p r o b le m . A ssessm ent o f P ro g r e s s . T h e d e g re e o f b r o n c h o s p a s m is e a sily e s tim a te d u sin g so m e f o rm o f tim e d v ita l c a p a c ity o r m a x im u m b r e a th in g c a p a c ity a n d th e n c o m p a r in g th e r e s u lts b e f o re a n d a f te r a b r o n c h o - d ila to r d r u g . P e r io d ic e s tim a tio n s a ls o giv e a v e ry g o o d id e a o f lo n g te r m th e r a p y . Chronic Bronchitis and Emphysema B y D r . L . D . E R A S M U S , M .B .,B .C h . ( R a n d ) M .D . ( P r e to r ia ) M e m b e r o f t h e F a c u l t y o f M e d ic in e , P r e t o r i a U n iv e r s ity . A L e c tu r e g iv e n to D e le g a te s a n d M e m b e r s o f th e S o u th A fr ic a n S o c ie ty o f P h y s io th e r a p y o n th e f i r s t d a y o f th e “ C h e st C o u r se” , w hich w as h e ld a t th e P re to r ia H o s p ita l P h y sio th e r a p y S c h o o l o n M a y 2 7 th a n d 2 8 th , 1960. A lth o u g h e i th e r o f th e s e c o n d itio n s m a y o c c u r s e p a ra te ly th e y a r e so f re q u e n tly a s s o c ia te d a s a lm o s t to a p p e a r in ­ s e p a ra b le . A n a lle rg ic f a c t o r o r f r a n k b r o n c h ia l a s t h m a is a f re q u e n t a c c o m p a n im e n t. C h r o n ic b r o n c h itis a n d e m p h y s e m a a r e c o n d itio n s o f p a r a m o u n t im p o r ta n c e b e c a u s e o f th e h ig h m o r b id ity a n d e v e n m o r ta lity b r o u g h t a b o u t by a c u te e x a c e rb a tio n s a n d c o m p lic a tio n s . T h e y o c c u r f r e ­ q u e n tly a n d re s u lt in te n s o f t h o u s a n d s o f lo st m a n - h o u r s ev e ry y e a r a n d tr e a t m e n t is f r e q u e n tly e x p e n s iv e , d r a w n o u t a n d u su a lly r e q u ire s h o s p ita liz a tio n .- lin ical H is to ry . E s ta b lis h e d c h r o n ic b r o n c h itis a n d e m p h y s e m a is u s u a lly p re c e d e d fo r se v e ra l y e a r s b y c h r o n ic c o u g h w h ic h is u s u a lly p r o d u c tiv e a n d f o r se v e ra l y e a r s b e f o re th e p a t t e r n b e c o m e s e s ta b lis h e d f re q u e n t a t t a c k s o f a c u te w in te r b r o n c h itis o c c u r. A tta c k s o f a s th m a a r e n o t in f re q u e n t. L a te r p e r s is te n t e x e rtio n a l d y s p n o e a o c c u r s a n d th is m a y be in te rs p e rs e d w ith m o r e a c u te a t t a c k s o f b r o n c h o s p a s m . T h e a t ta c k s o f b r o n c h itis m a y b e s u p p u r a tiv e in n a tu r e d u e to se v ere s e c o n d a r y in fe c tio n a n d e s p e c ia lly in th e e ld e rly d is a b lin g a n d e v e n fa ta l a t t a c k s o f b r o n c h o - p n e u m o n ia m a y o c c u r. T h e s e a t t a c k s f r e q u e n tly p r e c ip ita te c o n g e s tiv e c a rd ia c fa ilu re w h ic h a ls o o c c u r s p a r t i c u l a r l y in th e o ld e r ag e g r o u p w h e n a r te rio s c le r o s is a n d h y p e r te n s io n h a v e b e c o m e e s ta b lis h e d a n d h a v e a d d e d a n o t h e r b u r d e n . S e c o n d a r y p o ly c y th a e m ia f r e q u e n tly in c re a s e s t h e b lo o d v isc o sity a n d o c c a s io n a lly p a p ilo e d e m a a n d b lin d n e s s m a y fo llo w . A etiology. E x te rn a l f a c to r s -are f r e q u e n tly o f th e g r e a te s t im p o r ta n c e a n d th e in c id e n c e o f c h r o n ic b r o n c h itis is h ig h e s t in th o s e a re a s w h e re th e r e is p o l lu tio n o f th e a t m o s p h e r e b y in ­ d u s tr ia l g a se s a n d d u s t. C h r o n ic b r o n c h itis is a ls o m o r e f re q u e n t in h e a v y s m o k e rs . P o l l u t io n o f th e a tm o s p h e r e is ° f ° m i n g a w o r ld w id e p r o b le m . W e b r e a th e a s m u c h a s f h a ' r ^ w e ‘g h t in 24 h o u r s , e q u a l in w e ig h t to tin o o d w e c o n s u m e , b u t f o r m a n y y e a rs it h a s n o t o c c u r r e d to September, 1960 E m p h y s e m a is u s u a lly p e r m a n e n t a n d f re q u e n tly p r o ­ g re ss iv e a n d it is f r e q u e n tly o n ly a s s o c ia te d b r o n c h o s p a s m o r in f e c tio n t h a t c a n b e in flu e n c e d b y t r e a tm e n t. P u lm o n a r y f u n c tio n te s ts h a v e b e e n stu d ie d b e f o re a n d a f t e r th e a p p li­ c a tio n o f p h y s io th e r a p y to th e s e p a tie n ts a n d it a p p e a r s t h a t t h e d e g re e o f p u l m o n a r y f u n c tio n d e v ia tio n is n o t in flu e n c e d b y p h y s io th e r a p y . P a tie n ts w ith p le u r is y a n d p le u r a l e ffu s io n s h o w c o n s id e r ­ a b le im p r o v e m e n t in th e ir v ita l c a p a c ity a s th e c o n d itio n im p ro v e s . C o n g e s tiv e c a r d ia c fa ilu re . T h e d e g re e o f p u lm o n a r y o e d e m a is in d ic a te d b y a r e d u c tio n in t h e v ita l c a p a c ity . I n s o m e in s ta n c e s p u l m o n a r y c o n g e s tio n c a n b e d e te r m in e d a t a n e a r ly s ta g e b y m e a s u r in g th e v ita l c a p a c ity . T h e p ro g re s s o f p a tie n ts w ith w e a k n e s s o f th e r e s p ir a to r y m u sc le s c a n s o m e tim e s b e e ffe c tiv e ly f o llo w e d b y d o in g th e m a x im u m b r e a th in g c a p a c ity te s t. T h is is r e p e a te d a t s h o r t in te r v a ls a n d f a tig u a b ility w ill b e in d ic a te d b y p r o ­ g re ss iv e r e d u c tio n in s u b s e q u e n t te s ts. A s im ila r c lu s te r o f te s ts c a n b e d o n e a t a n in te r v a l o f d a y s o r e v e n w e e k s a n d p r o g re s s fo llo w e d in th is fa s h io n . I n c o n c lu s io n it m a y b e s a id t h a t p u l m o n a r y f u n c tio n te s ts d o n o t re p la c e o t h e r m e th o d s o f a s s e s sin g th e c o n d itio n o f t h e p a t i e n t ’s lu n g s b u t th e y a r e in m a n y in s ta n c e s a v ery v a lu a b le a d ju n c t. Page 7 m e n t o be a s f a s tid io u s a b o u t t h e a i r th e y b r e a th e a s t h e fo o d th e y e a t. W e w ill p r o b a b l y h a v e to p u t u p w ith g ro ss ly c o n ta m in a te d a t m o s p h e r e s f o r m a n y y e a rs t o c o m e . I r r i ­ ta t i o n f r o m d u s t in d u s ty o c c u p a tio n s s u c h a s m in in g is a ls o o f c o n s id e ra b le im p o rta n c e . A n in fe c tiv e a g e n c y is im p o r t a n t a n d t h e c o m m o n e s t in fe c tin g o r g a n is m is H . influenzae b u t a m ix e d b a c te ria l f lo ra is f re q u e n tly f o u n d . I n d iv id u a l p r e d is p o s in g f a c to r s in c lu d e a h e r e d ita r y te n d e n c y a n d a lle rg y . B a sic P a th o lo g y . I t is c o n v e n ie n t to c o n s id e r t h e r e s p i r a t o r y u n it a s c o n ­ sis tin g o f a te r m in a l a n d a r e s p ir a to r y b r o n c h io le le a d in g t o th e a lv e o la r sa c s. T h is m a y b e r e p re s e n te d in th e fo llo w in g f a s h io n in th e n o r m a l a n d th u s w h e n th e r e is b r o n c h ia l in f la m a tio n o r s p a s m i.e., w ith a n o b s tr u c tiv e f a c t o r in tro d u c e d . W ith e m p h y s e m a to u s d ila tio n , r u p t u r e a n d c o a le s c e n c e o f a lv e o la r sa c s o c c u r a s t h e re s u lt o f d e g e n e r a tiv e c h a n g e s in th e e la s tic fib re s o f th e a lv e o la r w a lls. T h e f a c t o r o f b r o n c h ia l o b s t r u c t i o n a n d in f e c tio n is f re q u e n tly s u p e r a d d e d a n d th e re m a y b e a s s o c ia te d i n te r -a lv e o la r fib ro s is. T h e s e c h a n g e s r e s u lt i n : — 1. A m e c h a n ic a l v e n tila to r y d e fic ie n c y w h e r e e x p ir a tio n e s p e c ia lly is d iffic u lt d u e to b r o n c h i o l a r o b s t r u c t i o n , lo ss o f e la s tic tis s u e a n d th e p a t i e n t h a v in g to e x p ire f r o m a n in itia l level o f h y p e r in fla tio n . 2 . In effic ie n t d is t r i b u t i o n o f th e a ir w ith in th e a lv e o la r sa c s o c c u r s a n d t h e im p a ire d d iffu s io n o f t h e g a sse s ■ o c c u r s . 3. I n t u r n a n o x a e m ia a n d c a r b o n d io x id e a c c u m u la tio n o c c u r s in th e b lo o d r e s u ltin g in a c id o s is a n d in c o m p e n ­ s a to r y in c re a s e o f th e b lo o d b ic a r b o n a te . I n te rm s o f p u l m o n a r y f u n c tio n te s ts t h e lu n g v o lu m e m a y r e m a in th e sa m e (a s w ill t h e v ita l c a p a c ity in m a n y in s ta n c e s ) b u t e x p i r a t o r y d iffic u lty r e s u lts in a i r tr a p p in g , {C o n tin u ed o n P a g e 14). P H Y S I O T H E R A P 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. ) Page 14 P H Y S I O T H E R A P Y September, 1960 A S P E C T S O F R E S P I R A T I O N (C o n tin u e d f r o m P a g e4 ). (iii) S tre n g th (size) o f th e r e s p ir a to r y m u sc le s— i n s p ir a to r y a n d e x p i r a t o r y (cf. th e r e s p ir a to r y m u sc le s o f th e tr a in e d a th le te ) ; (iv) E la s tic ity o f th e lu n g s (cf. th e re d u c e d v ita l c a p a c it y in a ll fo rm s o f fib ro s is o f th e lu n g s ); (v ) F u n c tio n a l e fficien c y o f th e n e r v o u s s t r u c tu r e s c o n ­ c e rn e d : (a ) r e s p ir a to r y c e n tr e , (b ) a n t e r i o r m o t o r n e u r o n s (cf. p o lio m y e litis ), (c) p e r ip h e r a l e ffe re n t o r m o t o r n e rv e s to th e r e s p i­ r a t o r y m u sc le s. W h y d o th e in s p ir a to r y m u sc le s re la x ? B e c a u s e th e y re c e iv e n o im p u lse s f r o m th e s p in a l c o rd m o t o r n e u r o n s , w h ic h in t u r n re c e iv e n o im p u lse s f r o m th e i n s p ir a to r y c e n tre . T h u s , th e c o n t i n u o u s d is c h a rg e o f r e p e titiv e im p u lse s b y th e i n s p ir a to r y n e u r o n s h a s t e m p o r a rily b e e n sto p p e d o r in h ib ite d , o r i n s p ir a tio n h a s b e e n c u t s h o r t to a llo w e x p i r a t i o n to t a k e p la c e . T h e r e s p o n s ib le m e c h a n is m s f o r th is a r e : (i) p n e u m o ta x ic c e n tre , (ii) e x p i r a t o r y c e n tre , (iii) H e r in g - B r e u e r reflex (v a g a l m e c h a n is m ). P n e u m o ta x ic C e n tre . T h is c o n s is ts o f r e s p ir a to r y n e u r o n s s c a tte re d in th e f o r m a tio re tic u la ris o f th e p o n s . T h e y m a k e s y n a p tic a l c o n ta c t w ith th o s e o f t h e i n s p ir a to r y a n d e x p i r a t o r y c e n tre s . A s t h e in s p ir a to r y n e u r o n s d is c h a rg e to t h e a n t e r i o r m o t o r n e u r o n s , th e r e is a s im u lta n e o u s d is c h a rg e to th e p n e u m o ta x ic n e u r o n s . T h e s e in t u r n d is c h a rg e to th e e x p i r a t o r y n e u r o n s . A t a c e r ta in c ritic a l level o f e x c ita tio n , th e l a t t e r e m it a b a r r a g e o f im p u lse s a t th e i n s p ir a to r y n e u r o n s , w h ic h f o r a s h o r t p e r io d , c o m p le te ly in h ib its th e ir d isc h a rg e . H e r in g -B re u e r re fle x . T h e d e lic a te a lv e o la r m e m b r a n e s o f th e lu n g c o n ta in r e c e p to r s s e n s itiv e t o th e a m o u n t o f s tr e tc h o f in f la tio n o f th e lu n g — str e tc h re cep to rs. A s a lu n g b e c o m e s p ro g re s s iv e ly m o r e in fla te d d u r in g in s p i r a t i o n , th e s e re c e p to r s a r e s tim u la te d a n d a s tr e a m o f a ffe re n t im p u lse s is c o n d u c te d a lo n g a ffe re n t v a g u s fib res t o t h e e x p i r a t o r y n e u r o n s , w h ic h a g a in in h ib it th e in s p ir a to r y n e u r o n s , a llo w in g e x p ir a tio n to ta k e p la c e . T h e r h y th m o f b r e a th in g is th e r e fo r e th e re su lt o f th e in te r a c tio n o f th e in s p ir a to r y , e x p i r a t o r y a n d p n e u m o to x ic c e n tre s a n d th e v a g a l m e c h a n is m . W h e r e a s th e d e p th o f a n i n s p ir a tio n is d e te r m in e d b y th e d e g re e o f d is c h a rg e b y th e in s p ir a to r y n e u r o n s t h e ra te o f r e s p i r a t i o n is d e p e n d e n t o n th e a c tiv ity o f th e p n e u m o ta x ic a n d v a g a l m e c h a n is m s . H o w is r e s p ir a tio n re g u la te d ? T h e r e s p i r a t o r y p a t t e r n (i.e. d e p th a n d ra te ) is re g u la te d , v ia th e r e s p ir a to r y c e n tr e , b y : (i) c h e m ic a l s u b s ta n c e s , a n d (ii) n e rv e im p u lse s . C h e m ic a l S u b sta n c e s. U n d e r a ll c o n d itio n s o f n o r m a l, e u p n e ic b r e a th in g , th e r e s p ir a to r y p a t t e r n is r e g u la te d a lm o s t e x c lu s iv e ly b y th e C 0 2 c o n te n t o f th e A r te r ia l blo o d . T h is is m e d ia te d th r o u g h a d ir e c t a c tio n o f th e H C 0 3 ( b ic a r b o n a te ) io n s o n th e r e s p ir a to r y n e u r o n s a n d c h a n g e s in a c id ity ( p H ) c a u s e d b y in c re a se d o r d e c re a s e d C 0 2. T h e n o r m a l te n s io n o f C 0 2 ( p C 0 2) in a r t e r i a l b lo o d = 40 m m . H g . I n c re a s in g th is v o lu m e b y a s little a s 2 m m . H g. is su ffic ie n t to d o u b le p u lm o n a r y v e n tila tio n ( h y p e r p n o e a ) ; h e n c e th e h y p e r p n o e a o f a c id o s is . S im ila rly a slig h t d e c r e a s e o f th is v a lu e c a u s e s a p n o e a ; h e n c e th e slo w sh a llo w b r e a th in g o f a lk a lo s is . In c e r ta in c a s e s o f a n o x ia , th e r e s p ir a to r y p a t t e r n is c o n tr o lle d b y th e 0 2 c o n t e n t ( p 0 2) o f th e a r t e r i a l b lo o d , via th e c h e m o r e c e p to r s o f t h e a o r t i c a n d c a r o t i d b o d ie s . N e rv e Im p u lse s. T h e s e h a v e a lr e a d y b e e n re fe rre d to e ls e w h e re . T h e h y p e r p n o e a o f m u s c u la r a c tiv ity is la rg e ly th e effe ct o f a f fe re n t im p u ls e s f r o m t h e c o n t r a c t i n g m u s c le s a n d m o v in g j o i n t s o f th e r e s p i r a t o r y c e n tre . D u r i n g o t h e r p h y sio lo g ic a l a c tiv itie s , e .g . ta lk in g , sn e e z in g , c o u g h in g , s w a llo w in g , e tc ., th e b a s ic r e s p i r a t o r y p a tte r n (a s c o n tr o lle d b y th e C 0 2— c o n t e n t o f th e a r t e r i a l b lo o d ) is m o d ifie d b y n e rv e im p u ls e s f r o m th e r e sp e c tiv e n e rv e c e n tr e s , a c tin g o n th e n e u r o n s o f th e r e s p ir a to r y c e n tre . P U L M O N A R Y T E S T (C o n tin u e d f r o m P a g e 1). r e d u c tio n o f tim e d v ita l c a p a c ity a n d th e m a x im u m b r e a th in g c a p a c ity . R e s id u a l v o lu m e is u s u a lly c o n s id e r a b ly in c re a se d b o th a s a n a b s o lu te v a lu e a n d a s a p r o p o r t i o n o f th e to ta l lu n g c a p a c ity . C lin ic a l F e a tu r e s . A n a d v a n c e d c a u s e o f e m p h y s e m a w ill th e n b e se e n to h a v e a n o x a e m ia w ith c y a n o s is h e ig h te n e d f re q u e n tly by s e c o n d a r y p o ly c y th a e m ia a n d s h o w s th e c o n s id e ra b le v e n tila to r y d iffic u lty a s s o c ia te d w ith h y p e r in fla tio n o f th e lu n g s a n d d iffu se e x p ir a to r y o b s t r u c t i o n . C lin ic a lly th e p a t i e n t w h e e z e s o n th e slig h te s t e x e r tio n o r e v e n a t r e s t a n d h a s t o u se h is a c c e s s o ry m u s c le s o f r e s p ir a tio n . T h e c h e s t b e c o m e s b a r re l- s h a p e d a n d th e rib s h o r i z o n t a l ly p la c e d . R e s p i r a t io n is c a r r ie d o u t p a r tia lly b y d ia p h r a g m a tic e x c u r s io n a n d “ e n b lo c ” m o v e m e n t o f t h e b a r re l- s h a p e d th o r a c ic c a g e . O n a u s c u la tio n th e p r o lo n g e d e x p ir a to r y d iffic u lty o f a f o rc e d m a x im a l e x p ir a tio n is u s u a lly q u ite e a s ily d e te c te d a n d in m y o p in io n th is is th e m o s t v a lu a b le s in g le sig n in t h e c lin ic a l a s s e s s m e n t o f th e p a tie n t. F o r th e m o s t p a r t a ls o th e r e is r e d u c tio n in a ir e n t r y a s j u d g e d by th e s te th o s c o p e . T re a tm e n t. T r e a t m e n t is d iffic u lt a n d p r o lo n g e d in m o s t in sta n c e s. I t h a s t o b e sa id a t th e o u ts e t t h a t e m p h y s e m a a s su c h c a n n o t b e in flu e n c e d b y t r e a t m e n t a n d a n y th e r a p e u t i c a t t a c k is d ir e c te d a g a in s t b r o n c h o s p a s m , in fe c tio n a n d v isc id se c re ­ tio n s w ith a v a r ie ty o f a g e n ts in c lu d in g a n tib io tic s , a n ti- s p a s m o d ic s , s te ro id s , d e te r g e n t a n d w e ttin g i n h a la n t a n d e n z y m e s ( s tr e p to k in a s e a n d try p s in ). A lth o u g h th e r e is n o t th e s lig h te s t d o u b t in m y m in d th a t P h y s io th e r a p y is o f c o n s id e ra b le v a lu e in m a k in g m o re e fficien t u se o f t h e p a t i e n t ’s n a t u r a l c a p a c ity f o r v e n tila tio n , th e r e is n o o b je c tiv e im p ro v e m e n t in p u l m o n a r y f u n c tio n te s ts in c o n tr o lle d se rie s o f p a tie n ts in w h o m th is h a s b een m e a s u re d b e fo re a n d a f te r p h y s io th e r a p y . C o m p lic a tio n s (e sp e c ia lly b r o n c h o p n e u m o n i a a n d c o r- p u lm o n a le ) a r e o f a s e rio u s n a t u r e a n d r e q u ir e v ig o ro u s t r e a tm e n t in th e ir o w n r ig h t. F r e q u e n tly th e n w e h a v e a p a t i e n t w h o is v e ry ill w ith g ro s s ly re d u c e d r e s p ir a to r y re se rv e a n d c o n s id e r a b le s e c o n d a r y in f e c tio n in th e lu n g s w ith a s s o c ia te d c a r d ia c f a ilu re a n d a w id e , v ig o r o u s a n d p e r s is te n t th e r a p e u t i c a t t a c k is in d ic a te d . A s f a r a s f u tu r e d e v e lo p m e n ts a r e c o n c e r n e d , h o w e v e r, p r e v e n tio n is lik ely to p r o v e m o r e r e w a r d in g th a n a n a t t e m p t a t c u re . 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. )