348

Significance ofMicrobiological and Biochemical Ana lyses in Empyema Thoracis W Ebert. II. G. Bauer. E. Bau er. and G. Trefz Thoraxklinlk. lIeidelberg -Rohr bach . FHG

Followi ng the indi fferent resul ts of a r etrospectiv e a nalysis . a pr osp ective s tudy was un dertaken to a nalyse th e causative organisms in 51 cas es of em pyema. Cultu res we re posi tive in 44 / 51 1= 86 .3%1 cases. 2 bacteria l sp ecies we re recovered for

each empyema . The aero bic gram-positive cocci represented the largest group (57 %1. followed by aerobic gram -negative ba cteri a (18 .6 %), a naer ob ic ba cteri a (18. 6 %), a nd fu ngi 15 .8 %1.

Polymicrobial empyema accounted for 59.1 % of the case s. Ana ero bic bacteria were culture d from 36 .4 % of em pye ma .

Anaer obic bacteria were more freque ntly isola ted from pleural effusions tha n from othe r specime ns. Swa bs wer e found to be of minor va lue for a naerobics. Analyses of glucose and pll value in pleura l effusions have bee n reported to be useful in differentiating compli cated from uncomplicated effusions in cases where the aspi rate d fluid is not purul ent and is negative on gra m sta in. but clinical as well as rad iological findings point to a n em pyema . Our resu lts have show n tha t pll -values < 7.30 an d Glucose < 60 mgld l we re not abso lutely specific for empyema. In contras t. PMN-elastase in pleu ral elTusion an d 111-30 in ur ine sho wed a sta tistically significa nt differen tia tion of em pyema from exudates of othe r origin.

Bed eutung mikrobi ologisch er und bioch em isch er Analysen be im Tho raxempye m Die bak teriologlsche Untersuchung von 5 1 Empyern en Iilhrte in 86 ,3 % zum Nachweis des ursach lich en Erregers . 1m Durch schniu wurden pr o Empyem 2 Erregc r angezuchtet . Es dominierten die ae robe n gra rn-positiven Kokken (57 %), gefolgt von den ae robe n gra m-nega tiven Bakt erien (18.6%). Anaer obiern (18.6 %) und Pilzen (5.8 %).59,1% der Empyem a waren polyrnikrobi ell inflziert . Ana erobier konnten bei 36 .4% der Empyema angeziichtet we rden . Der Anaerobiernach weis gelang am haufigsten a us ErguBfliissigkeit. Abstrichtup fer waren flir die Ana erobierisolie rung wenig er geeignct. Die Bestimmung von GIukose und pi I-We rt im Pleu ra erguB ka nn zu r Untersc heidu ng zwische n komplizierten und unkomplizierten Fa llen hera ngezogcn worden. wenn kein Eiter aspirie rt wird und die Gra mfa rbung nogauv ist, e bc r a ufgrund de r Klinik und des Hdntgenbildes ein Empyem anzunehme n ist. Unsere Untersuchunge n haben jedoch guzolgt. da B pll-wc rtc < 7.30 und Glukoses piegel < 60mgldl fur das Plcurnemp yern nich t spez ifisch sind. Im Gcgensa tz zu Glukose und pll-wert lieBen sich mittel s PMN-Elastase im ErguB und 11 1-30 im Urin Empyeme statist isch signilikant von Exsuda ten an de rer Atiologil' unte rschei de n.

Key words

Empyema thuracis - Ca usative organ isms - Biochem ica l Analyses

lntroduction The bacteriological anal ysis of the pleural elTusion has a differ ential dia gnostic import an ce. sharply outlining in case of a positive result the other causes of pulmon ary infiltrations which can simulate pneumonia. e. g. tub er culosis. tumours. embolism, or vascular diseas es . About 40 % of the pati ent') with bacterial pneumonias or lung abcesses wer e known to have pleural effusions, but only 5 % of cases with parapn eum ological elTusions develop an exudate with microbi ological. chemical, a nd physical cha racteristics of em pyema thoracis (9). The empyema thoracis is a special form of the inflam matory pleural effusion. The exudate is clear in the beginning, but changes its characteristics through the invasion of leuko cytes . The developin g. purulent empyema fluid consists of large am ounts of microorganisms, which may be det ected micros copically or ca n be cultured . If non e arc detected it is considered ster ile.

While the uncomp licat ed elTusions may spontaneously resolve with approp riate antibiotic treatm ent. the empyema requires dra inage or/and su rgica l interventi on. \Vhen the as pira ted fluid is not purulent and is gram-negative. but clinical and rad iological findings point to a n empyema. an alysis of biochemical parameter s is useful in as certaining pr oper treatm ent. Drainage is unavoidabl e in cases of pleural elTusions with a pH valu e < 7.:10 and glucose < 60 mg/dl (13). Past decad es have sh own repeat ed cha nges in the orga nisms ca using empyema . In the preantibiotic era, the most domin ant bacteria found were pneumo cocci a nd stre ptococci pyogenes . In the forties the availab ility of penicillin allowed staphylococcus aureus to ta ke the lead over pneumococci and strepto cocci pyogenes. After the introduction of beta- lactam as e-stab le penic illins the pattern of causative organisms furt her expanded to include gra m-negative bacter ia and anaerobi c bacteria (2. 6).

Thorac. card iovasc. Surgeon 3X ( 1990 1

Received for Puhlica tio n: March 29. 1990

34 X - :~ 51

© (;porg Thieme Verlag Stuttgart . New York

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Summa r)!

Significance ofMicrohi%gica/ and Biochemical A na/y,w'sin Empyema TJwracis

Material a nd Methnds Bacter iological and mycological sta nda rd methods we re used in a nalyzing causat ive orga nisms in 5 1 case s of empyema with dilTerent etiology (meta pneumoni c: 66 .7 'J!o. tuberculosis: 17 .6 %. tra uma tic: 3.9 ':;'•. miscellaneous : 11.8 %1. In add ition. 67 pati ents with maligna nt pleur al effusions (including 15 with pleural mesothelioma . 4- 7 with pleur itis carcinomatosa. and 5 with accompan ying emp yema) a nd 44 patients with benig n ple ural effusi ons (I8 with pleuritis tuberculosa . 26 with uns pecific pleuritis , including 11 with ompyema l were used to determ ine the differential diagnostic s ignifica nce of pll value. glucose. and the inllammatory mar kers !'f\-t N-elastase (ELISA. Merck. Da rmstadt) a nd 111 -30. 1I1·;{0 was determined with a self-esta blished ELISA using a monoclonal a ntibody (151in the ur ine of 9 patients with empyema, compa red to 22 pa tients wit h pleur itis tuherculosa a nd 123 hua lthv individuals . . The statistical compa rison of groups was done with the KruskaJ- p"allis lest (7) in combination with multiple comparisons of

349

Causative organism 67 isolates I 45 effusions 1.5 organisms I effusions

10

10

1.1.1989 - 31.12.19 89 30

26.9

'0

10

o

staphylo-

strepto-

entero-

cocci

cocci

cocci

gram-neg. anaerobes fungi rods

Fig. 1 Proportionoforganisms in45/293 positive pleuraleffusions ofdifferent etiology

pleu ral effusio ns s howed mnnoinfectinns, while 3 1. 1% s howed polymicrobial infection s. Positive cultures of bacteriological and mycological infections wer e found in 44/ 51 186.3 'Xl) cases of empye ma . Most of th e orga nisms were able to be cultu re d from d rai nage swabs (73,3%), pleural effusion fluids 131.4 %), and effusion fl uids deriving from surgical pro cedures (11.WYo) . 13.7 % of the empyema were sterile . Th e reasons for sterile em pyema a re prean tibiotical treatm ent, using inaccurate bacteriological tech niques as well as imper fect grow ing conditions, an d the mortifi cati on of organ isms in pus (14). In the analyses of Poll s et al, (l 3) 20 % and Yeh et al. (191 37 % of em pyema had negative cultures . Fig. 2 shows a histogram of the causa tive organ ism of the 44 positive empyema cultures. The ratio of gra m-pos itive cocci compa red to gra m-negative bacilli a nd an aerobic bacter ia was found to be 3 : 1 : 1, This spectrum diners esse nt ially from the resu lts of our retrospect ive study with a ratio of 7 : 3 : 1 (3), The distr ibution of a naerobic an d ae robic infections are shown in Fig. 3. The pie cha rt indicates that th e ca use of empyema thro ugh a naerobic bacter ia see ms to be a main factor (36.4 %).

Bacteriology of empyema the-ace n _ 44

lmnn (4 1. 86 isolates f 44 empyema

%

lIesul ts and Discussion

70

In the time fra me of Jan , I - Dec, 31, 1989, 45/2 93 (- 15.4 %) of th e microbiologically exa mined cases of pleural effusions showed positive cultures, Of tho se 35,6 % had em pyema , 67 isolates wer e culture d from 45 positive effusions (1.5 organisms/effusion). Fig. 1 shows th e causa tive orga nisms ,A rem arkably high porti on of anae robic bacteria (22.4 %) was found , In 66,7% of the cases of pleural effusions only aerob ic bacteri a were found and in 15.6 % of th e cases only anae robic bacteria were isolated. In 17.8 % of th e cases a mixed aerob ic/anaerobic infection was found to be presen t. Within the a nae robes the gram-negati ve and penicillin-resistant B, frag ilis an d B, th etaiotaomikron wer e th e dominant agent s (46,7 %), 68 ,9% of the patient s with

60

, .96 organisms I empyema

50 40

staphyloCOCCI

_

Fi g.2

streptococci

organisms in isolates

entero

gram-neg roes

COCCI

•

anaerobes

fungi

organisms In empyema

Proportion of organisms in 44/51 positive empyema thoracis

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In a previous retro spective study, the causa tive orga nism s of 1(l2 empyema cases were investigated (4). Culturing succeeded in 13 2 (81 .5 I Xl) of cases. Out 01'2 35 isolates. 22 d iffe rent s pecies were cultured. Of th ose cultur ed . ae robic gram- positive cocci wer e dominant (61.7 1!{l) followed by aerobic gra m-negative rods (21.7%), an aer obic bacte ria (8 .5 %1. and mycobacter ia (5 .1 'Yo). That distribu tion of causat ive path ogens within the aer obe s is in accordance with the resu lts of other investigations 15,8, 10, 11, 16), Larger discrepanci es, however , were noted in the a naero bic bacterial ran ge. The per cent age of an aerob ic isolates quoted in th e literat ure va ries from 1 % (16) up to 65% (1). Inadequate bacterial techniques an d pre an tibiotic th erapy were the ma in reasons for th ose difTer ences (17). Prerequisites for success ful a nae rob ic bacteriology a re collecting of proper speci mens and performing sim ultaneo usly anaerobic and ae robic cultures. Durin g th e first 3 yea rs of that study specimens were se nt out to laboratories other tha n our own . The res ults obta ined showed a com para tively low isolati on rate of 8 .5 °,{) for anae ro bes . These findings motivated us to untert ake a prosp ective st udy in which we would culture th e speci mens in our own la boratory by use of conse quent anae robic diag nostic proced ures. During the time fra me Jan. f - Doc . 3 1, 1989 we a nalyzed the ca usa tive orga nisms in 293 pleural effusio ns of differe nt etiology as well as in 5 1 cases of empyema . At the sa me time, th e biochemical par am eter s pH value , glucose, P!\'lN-elastase a nd HI-30 were exa mined for diagnostic specificity in empye ma thoracis .

Thora e. card iol'asc..)·llrgeo1l 38 (199())

W h'fwr t. /I . G. Bauer. I:'. Bauer. G. Tn1=

'l1lOrw:. nmliol' (/sr:. .r,'/lf J/co/138 f1 99{})

Bacteriology of empyema thoracis n = 44

Bacteriology of empye ma thoracis n = 44

monoinfection

40.9% polymicrobial infections

aerobes I anaerobes

25.0%

2: 3 organisms 31.8%

Fig. 3 Proportion of aerobic, anaerobic, and mixed aerobic/anaerobic infections in 44/5 1 positive empyema thoracis

Fig.4 Proportionof mono-andpolymicrobialinfections in 44/51 positive empyema thoracls

Ta ble 1 lists th e test mat erials wh ere t he culturing of an aerobes succeeded. The effusion fluid was the most s uccessful for th e detectio n of anaero bic ba cteri a and is , th erefore, the best s pecimen for the a na erobic bacteriology. It is desirab le to aspirat e the material (so me mil into a syringe (withou t this preca ution a naerobic conditions a re not given r. Swa bs were found to be of minor value du e to th eir inability to gather adequate am ount s of material as well as exposing the mat er ial to outs ide oxygen. In spite of using an app rop riate tra nsport tub e , th e specimen needs to be placed under anaerobic cond itions imm ed iately. Th is is to exclude a n overgrow th hy ae ro bic bacteria .

pleuritis showed pl l values < 7.30. E1lusions or other etiology ha ve also been found to show low pl l values: X5 % of rheuma tic pleuri tis effusions and 100 % of ru ptu red oesophag us effusions were of pl l value < 7 .:~ O (141. Through the a nalyse s of the rheum ati c factor ltiter > 1 : 320l an d amylase (offuslon amylase > serum a mylase ) one ca n d ifferentiate effusions of such etiology. Pleural effusions of a ll em pyema displayed glucose levels < 60 mg/d l. Low glucos e levels wer e a lso fou nd in 1O.4 l XIof th e pat ients with pleu ritis ca rcinoma . 1(1.7 % of'the patients with pleu ram esot heliom a. 1 1.7 % of the pati en ts with pleu ritis tube rculosa . a nd 11.7 % of the pat ients with unspecific pleurit is. In infl a mm ato ry p rocesses Pi\l N-elastase ha s bee n found to be a specifi c marker (12 1. PMN-elas tase is released fro m primary gra nula of polymor phonuclea r leu kocytes in those cases , where phagocytosis of microorganism s is imp ossible d ue to the s ize of the particles (i , e. frustrated pha gocytosis). The release d elastase is imm edi ately boun d by (t' l proteinase in hibitor in the extrace llular s pace . Since the Pj\ l Nelastase-a ] pro teinase inhibitor com plex has a very short life-time the magn itude ofits conce ntr ation revea ls an actu al view of the infla mmatory process. Fig. 5 shows a scatterg ra m of PMN-elasta se values of pleural effus ions. The P!\'l N-elastase conce ntrat ions were me asu red to be in empyema 1793 ± 585 ng/ml, in pleuritis ca rcinomatos a 4 26 ± 670 ng/m l, in pleu ral mesothelioma 275 ± 45X ng/m l. in pleu ritis tuberculosa 36(1 ± 44 4 ngl ml, a nd in unspecific pleuritis 344 ± 68(1 ng/ ml. The difference between empyema a nd the control gro ups wa s statistically highly significa nt (p < 0.00 1I. The locally occurri ng amou nt of a ] prot einase inhibitor is una ble to neutra lize excessively released elastase . Therefore, this protease dest roys pro teins like elas tin. collagenes . immunoglobulins. a nt ith ro mbin III or inter-n-trypsin-inhi bitor. H I -:~ () is a 30 KD a protein wh ich is fra gmented from inter-o -trypsininhibitor by the ac tion 01' elastase. HI-30 is excre ted into the u rine (15). The measurement of u rinc- III-30 ca n be used to es timate the exte nt ofan inflammatory process. \Ve found in th e urine of the gro up with empyema a mea n 11 1-30 concent ra tio n of 21 .6 ± 25.1 p.g/ rng creatinine. Th is is in contrast to the res ults of the contro ls (pleurit is ca rcinomatosa : 1.1 ± 0.8 p.g/ mg crea tinine, pleu ritis tube rculosa : :t X ± 6.3 p.g/m g creatinine. and healthy ind ividuals:

Table 1 Detectionrates of anaerobic isolation in different specimens Thoracentesis Swabs from drainage fluid Pleural fluid/operation' Others

10116 ~ 62.5% 311 9 ~ 15.8% 3/6 ~ 50% 0/3 ~ 0%

, Pleura! fluid collected during operation

Due to polvnucro bia l empye ma . accoun ting for 59.1 l XI of the cas es (Fig. 4), a ntibiotic treatmen t in form of polychernotherap y was necessary. Th e com bination of cepha losporin or acylure idnpen icillin and aminoglycosids as well as met ro nida zol were used in our clinic . rVinlerbau er (1Xl recommends t he following combinations: clindamycin a nd tobrumycin. celoxitin a nd pipe racillin, cotrimoxazol and cefoxitin as well as cot rimoxazol and piper acillin. Clindamycin a nd tobr am ycin a re effective aga inst most aero bic cocci. gram neg ative bacilli a nd anaero bics incl uding hacterioides s pecies. All the other combinations are broadspectrum a nti biotics without the da nger of ca using ne phrotoxicity a nd ototoxicity by the a minoglycusid es. The biochem ical ana lyses of plI va lue and glucose in infl am matory pleural exuda tes have been reported to be useful in diffe ren tiating complicated from un complicate d effusions (14). In our survey all of t he em pyema show ed pI! values < 7.:W. However. the decreased pH value was not specific for empyema, since 16.1 l XI of the patien ts \.. . . ith pleuriti s ca rcinoma , 13 .6 % of the pat ients w ith pleu ritis tube rculosa , a nd 43.WY.1 of th e patients with unspecific

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:~5 ()

Significance a/Microbiological an d Biochemical An alyses ill Empye ma Ttiorncis

References

PMN-elastase in pleural effusions

2400

I

,"

2

2400

3

2000

of

1600

1200

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800

..

Il

---_ _--- - r- rs -: - > 400

:

,

9

'.' T . T. :.' , ',' T T ...:. . . . ..I·· . . . . ', .L .:1:.

HI

,j:l.

.1.

pleura carcncmatose pulmonary extrapulm.

mesotbeucma

pleuritis tuberculosa

:J51

vnspec. pleuritis

empyema

Fig. 5 PMN-e lastaseconcentrations, median values with 95%confidence intervalsin pleural effusions of different etiology. Open circles: empyemathoracis or accompanyingempyema

11

12

13 14

15

I II

0.3 ± 0.1 I' g/m g cre atinine ). The group with empyema was stati stica lly significantly dilTe rent from the control groups tp < O.O ll. In summa ry. as our study shows. a consequent ana erobic bacterio logy is necessary to compre hend th e entire spectrum of the causative organ isms of empyema (2, 6). However. we wer e not ab le to detect an a nae robic part nea r th e 65 % repor ted in the study of Bartlett et al. (I I. PMN-elastase and HI-3D were found to be specific param eters of the inflammatory pr ocess, while pH value and glucose wer e of minor value.

17 11\

1'1

Bartlett. J. G., S. L Gorbach. II. Thadepa tti, and 5;. st. Firwgold : Bacter iology of empyema . La ncet I (1974) 3:l8-340 Bry a nt, N. E.: Pleu ral Effusion and Empy ema. In: Ma ndel l. G. L N. G. !Jougl as. 1. Eo Bennett (eds.l : Prin cipl es and Pra ctice of Infectious Dise ase s. 3 rd Edition. Church ill Livingstone . New Yor k-Ed inbu rgh - London -Melbourne (1990155 5- 56 0 Dunn, O. 1.: Multiple compa riso ns using ra nk su ms. Technome trics 609641 241 - 252 Ebert . W.. II. Bidzebm ck und II. G. Bau er: Errege rs pe kt rum beim a kutcn und ch ro nischen Pleura em pye m . Langen becks Arch . Chir. Suppl. ((((1 9891t 87 - 190 Gesl in. P.: Bacter ial pleu ral effus ion . In: Pennington. J. Ii. tedj: Resp ira tory infection : Diagn osis an d Manage me nt. 2"d Ed. Haven Press . New York (19831 269 - 278 Johnson. C. c.. and S. M. Fineoold: Pyogenic Bacterial Pne umo nia. Lung Abscess. a nd Empy ema . In: Murmu . J. F.. .I. A. Nadel Ieds .): Textboo k of Respirator y Medic ine . W. B. Saunde rs. Philad elp hia - Lo ndon-Toronto (19 881 803- 8 5 5 Krus kal. W. II.: A non pa ram etri c lest for the severa l sa m pling problem . Ann . Mat h. StaL 23 (195 2) 525 -540 Leb lanc. K. A. an d W. Y. Tuck er: Empye ma of the tho ra x. Surg . Gyn. Obstct. 1580 984166 - 70 Light , R. W.. W. M. Girard. S. G. Jenk inscns. and H. tt. George: Par a pneumon ic e ffusions . Am. J. Med . 69 (19 80198 5 - 98 (, t.utz.A; O. Grooten. et M. A. Berger : Conside ra tions ii. prop os de s ge rmc s lsole s da ns 683 cas de plcur esies puruleutes . Str asbourg Med.14 0 963 11 19- 128 Manda t. A , K.. a nd II. Thadepalli: Tr eat ment of'spon tauoous ba cter ial em pyema thoracis. J. Thorae. Card iovas c. Surg . 94 (1987) 414 -41 8 Neumann. S. uud II . t.anq: Ent zundung. Ill: Greilinc. /I. . A M . Gressner Ied.l: Lehrbuch de r klinischen Chemic lind Pa thc biochemie . Schattauer. Stuttga rt- New York (1987 )1 022 - 105 4 Polls, D. E . D. C. Lev in, a nd S. 11. S a/Ill: Pleura l fluids pl l in par apneu moni c effusions. Chest 70 (19 76 ) 3 28 - 33 1 Sahn . S. A : The Pleura (State of the Artl. Am . Hev. Hosp. Dis. 138 ( 988) 184 -2 34 Trefz . G., B. S treit. C. W. t: .tus tns. ~v. libert, a nd At. IJ. Kra m er: ELISA for the de term inati o n of urina ry tryp sin in hibitor using a monoclon a l antibody . Clin. Sci.• in press ~Ve es e. W. C.. H. R. S chindler. I. M. Sm ith. and S, Rubincoich: Em pyema of the thorax the n a nd now. Astudy of 12 2 ca ses over fou r decades. Arch . Intern . Med . 13 1 (19 73 ) 5 l(,- 520 Wern er. 11. : Ana erobier-In fcktic ne n. Path ogeu cse. Kliuik . Th era pic. Diagno stik . 2. Aufl. Stuttga rt-N ew York. Th ieme 119R51 Win te rbauer. N.II. : In: Fishman. A P. (ed.l: Pulm onarv Disease a nd Disord er s. 2 nd Editi on McGraw-lIi11 . New Yo rk (1(88 )-2 139-2 157 Yeh. 7: J..D. P. IIall, H. G. Ellison: Em pye ma thoracis . A review . Am. Hev. Hesp. Dis . 88 (196 3) 785 - 790

Prof Dr.

tv. Ebert

Thoraxklinik Ileidelberg:-Hohrbach Amalic nstra t lc 5 D-69 00 Heidel be rg

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ng/ml

Thome. eardiol'usc. 5;/lrgeo" 38 (199{))