Bronchoscopic Protected Catheter Brush for the Diagnosis of Pulmonary Infections

Bronchoscopic Protected Catheter Brush for the Diagnosis of Pulmonary Infections* Charles-Hugo

Marquette,

Rene Courcol,

M . D , t Benoit

Andre-Bernard

Tonnel,

M.D.;

Philippe

Wallaert,

M.D.;

Ramon,

M.D,,

M.D.;

F.C.C.P.;

and Cyr Voisin, M.D.,

F.C.C.P.

A new bronchoscopic-protected catheter brush (BPCB),

nosa), was performed with the brush. Culture of brush

designed to obtain uncontaminated bronchial secretions,

specimens of each type of catheter grew the marker

was studied in vitro and in vivo. The device was composed

organism in pure culture and obtained the same amount of

of a standard biopsy brush, protected by a single catheter

bronchial secretions (0.001 ml). The manual vortexing of

and occluded with an agar plug. Ejection of the plug was

the brush in the transport medium (Ringers solution)

obtained neither by advancing the brush nor by advancing

proved to be as effective as the mechanical vortexing so

an inner cannula (as in a telescoping catheter brush), but

that transecting of the brush was no longer mandatory. In

instead, by an air flux, provided by a syringe which was

the second part of this study, paired bronchial samplings

connected to the proximal tip. In the first part of the study

from 27 patients were performed using both types of

the ability of the B P C B to obtain uncontaminated specimens

catheters and similar results for both were obtained. In

was tested in comparison with the reference telescoping

these in vitro studies, completed by a clinical trial, our

catheter brush ( B F W brush 10/70/90, Medi-Tech Corp

single-sheathed, plugged catheter brush proved to be as

Watertown, MA). Catheters of each type were successively

reliable as the double telescoping catheter brush. However,

passed through the inner channel of a bronchofiberscope

because of its relatively simple conception, making it easier

which was contaminated with Klebsiella pneumonia. After

to use and lower in cost than the double catheter brush,

ejection of the distal plug, sampling of bronchial secretions

routine use of this sampling device should be considered.

infected with a marker organism (Pseudomonas aerugi-

T N critically ill patients, patients receiving immuno-

The drawback to this device, however, is its high cost,

-"- suppressive therapy and in patients undergoing

which prohibits its routine use. We therefore devised

long-term hospitalization, nosocomial pneumonia is a

a new catheter that was both easier to use and less

major setback. The empiric choice of specific antimi-

expensive. Our purpose was to compare the reliability

crobial

because

of this new catheter to that of Wimberley for the

various types of bacteria may account for these in-

recovery of bacteria in vitro and from the tracheobron-

fections:

chial tree.

therapy is difficult

in this setting

Gram-negative bacilli,

S aureus and S pneumoniae.

13

anaerobic bacteria,

Therefore, the success-

ful treatment of these infections requires prompt and

Seeking the significance of quantitative

bacteriologic count in the diagnosis of nosocomial pneumonia was outside the scope of this study

accurate bacterial diagnosis. Bacteremia and empyema,

though diagnostically

definitive

occur too infrequently to be of u s e .

4 6

when

found,

Moreover, in

MATERIALS A N D METHODS

spite of various methods aimed at better specificity,

Description of the Device

direct examination and culture of expectorated sputum

The reference device was the plugged telescoping catheter brush, described by Wimberley et al (BFW brush 10/70/90, Medi-Tech Corp Watertown, MA) and will be referred to as MEDI. Our device (called CAL, as in Calmette Hospital) was made in a similar fashion and used the same standard biopsy brush (Cytobrosse BC 12C Olympus Corp, New York) to collect bronchial secretions. Instead of a double telescoping catheter, however, we used a single catheter (53795, VYGON, Ecouen, France) with a double port (Vygon 88900) on its proximal tip (Fig 1). The brush's rod transfixed a rubber cap, thus ensuring air-tightness. In the second port, an air-filled syringe (10 ml) was connected, permitting ejection of the agar plug occluding the distal end (Fig 1). Following decontamination of each part of the device in glutaraldehyde (2 percent) for a period of 45 minutes, the device was assembled without the agar plug, placed in a bag, and sterilized with ethylene oxide. Just prior to use, the agar plug was positioned by introducing the distal tip into a glass vial containing 3 percent agar.

samples are misleading because of sample contamination with oropharyngeal

flora,

413

While

transtra-

cheal aspiration and percutaneous lung aspiration can circumvent this problem, they cannot be performed in thrombopenic or intubated patients and may cause life-threatening c o m p l i c a t i o n s .

1421

Even

fiberoptic

bronchoscopy aspirates are not devoid of contamination.

22

Hence, the benefits of the Wimberley broncho-

scopic protected catheter brush which permits the sampling of uncontaminated bronchial secretions.

23

*From the Department of Pneumologie, HopitalA. Calmette, Lille, France. tService de Bacteriology, Manuscript received May 4; revision accepted September 14. 746

23

Diagnosis of Pulmonary Infections (Marquette

et al)

W I M B E R L E Y S CATHETER

a

——\

plug

MODIFIED CATHETER

I

EL

FIGURE 1. Single catheter brush with double port on its proximal tip, permitting ejection of the distal plug with an air flux provided by a syringe. Secretion Sampling Method As described by Wimberley et al, the catheters were passed through the inner channel of a fiberoptic bronchoscope to approximately 4 cm beyond the tip of the bronchoscope. The distal plug was ejected, either by flushing the air with the syringe connected at the proximal tip (CAL), or by advancing the inner cannula 3 to 4 cm beyond the tip of the outer sheath (MEDI). The brush was advanced into the secretions and then withdrawn several centimeters into the catheter. After removing the catheter from the bronchoscope, the distal portion of the catheter was cleaned with 70 percent ethanol, wiped dry, and transected with a sterile scalpel blade, distal to the brush. The brush was advanced beyond the sheath and severed with a sterile wire-cutter into a screw-capped glass vial which contained 1 ml of sterile Ringer's solution. The glass vial was then mechanically vortexed. 23

Bacteriologic Processing Serial, ten-fold dilutions of the sample were prepared with final dilutions of 10" , 10" , 10" , and 10" . One hundred u.1 of the undiluted specimen and of each dilution were plated on different media (Pasteur Production, Paris) for quantitative culture: purple lactose agar, 5 percent blood Columbia agar, 5 percent blood Columbia agar (to which nalidixic acid [40 mg/L] was added for Streptococcus pneumoniae cultures) and "chocolate" agar (to which bacitracin [30 U/ml] was added for Haemophilus sp cultures). Microorganisms were identified by standard methods. No attempt was made to isolate anaerobes. 2

3

4

5

In vitro Experiments Comparison of both devices The design of the experiment was similar to that described by Wimberley et al. Two specimens of infected bronchial secretions were prepared (Klebsiella pneumoniae 8.10' CFU/ml: specimen K and Pseudomonas aeruginosa 10 CFU/ml: specimen P), one to be used as the "contaminator" of the bronchofiberscope, the other as the marker organism to which the brush would be exposed. We used specimen K first as the "contaminator" and exposed the brush to specimen P The distal tip of a bronchoscope (BFB Olympus Corp, New York) was immersed in a beaker containing specimen K, which was suctioned into the inner channel in order to mimic contamination occurring during passage through the upper airways. Seven catheters of each model were 23

7

2

passed, in succession, through the channel and subsequent sampling of specimen P was performed (as described above). Fiberscope contamination was repeated between each catheter passage. To be sure that Pseudomonas had not falsely inhibited growth of Klebsiella in culture, the reverse experiment, with Pseudomonas instead of Klebsiella, was performed with seven catheters of each type. Comparison between mechanical and manual vortexing: In an attempt to avoid sectioning of the brush, which is needed for its vortexing in the glass vial, we compared mechanical and manual vortexing. A dilution method was used to measure the amount of bronchial secretions released into the vial containing Ringer's solution. Four brushes (Cytobrosse BC 12C Olympus Corp, New York) which have the same dimensions as the Meditech brushes) were dipped into a beaker containing bronchial secretions infected with Klebsiella pneumoniae 1.4 x 10 CFU/ml. Secretions from the brushes were released into 1 ml of Ringer's solution, either by one minute of manual vortexing, or by mechanical vortexing (brush aseptically transected and placed in a screw-capped vial). Serial dilutions of the samples were plated on purple lactose agar medium for quantitative bacterial count. 8

In vivo Study Our purpose was to compare bacteriologic results yielded by each type of catheter in vivo; therefore, we used both catheters, successively during each bronchoscopic examination in 27 patients from an intensive care unit. Fifteen were intubated, three were tracheostomized, and 16 were under mechanical ventilation. All patients presented with fever and pulmonary infiltrates on chest roentgenogram and received inefficient empiric antibiotic therapy No incident occurred during or after the bronchoscopic procedures. The fiberoptic bronchoscope (Olympus BFP10) was introduced into the endotracheal tube by a connector (Bodai Suction-safe, Sontek Medical), ensuring air-tightness in ventilated patients, and placed in the bronchus which drained the lobe affected by the infiltrate. Secretion sampling and bacteriologic processing were performed as described above. Statistical Methods For the comparison between mechanical and manual vortexing we used Student's nonpaired t test. To compare results of bacterial counts yielded with both catheters in each patient we used the

CHEST / 93 / 4 / APRIL, 1988

747

Table 3—Comparison of Manual and Mechanical Vortexing

Table 1—Results of Bacterial Culture of Bronchial Secretion Samples Collected with Both Types of Catheters In V i t r o

Bacteria

CAL Catheter Bacterial count (CFU/ml)

M E D I Catheter Bacterial count (CFU/ml)

P aeruginosa P aeruginosa P aeruginosa P aeruginosa P aeruginosa P aeruginosa P aeruginosa

0.59x10 lxlO 1.4X10 1.7X10 l.lxlO 1.3XH>| 1.2x10*

0.34 xlO* 2X10

4

4

1.2x10*

4

2X10

4

4

1.8x10* 1.2x10* l . l x 10

1

4

Bacterial count performed on the vial containing Ringers solution in which the brushes had been vortexed. Contaminating organism was K pneumoniae (8.10 CFU/ml) Marker organism was P aeruginosa (10" CFU/ml) 7

Brush No. 1 2 3 4

Mechanical vortexing Quantitative bacterial count (CFU/ml)

Manual vortexing Quantitative bacterial count (CFU/ml)

8x10* 12x10* 27x10* 22x10*

18x10* 28x10* 12x10* 21x10*

K pneumoniae K pneumoniae K pneumoniae K pneumoniae

Each brush was dipped in a bronchial secretion specimen infected with K pneumoniae (1.4 x 10 CFU/ml) and was then vortexed in the Ringer's solution containing vial to resuspend the recovered secretions s

Comparison

between mechanical

and manual vor-

texing. Results yielded by either manual and mechanical vortexing of the brushes were compared (Table 3).

Students paired t test. To compare the differences of bacterial species recovered with either catheter we compared the frequencies of recovery of each species with either catheter (Student's nonpaired (-test).

in samples

CFU/ml. Mean concentration in the samples obtained after mechanical vortexing was 17.25x10* CFU/ml. However,

RESULTS

this difference

is not significant. Thus,

mechanical and manual vortexing yield similar results.

In vitro Studies Comparison

Mean concentration of K pneumoniae

obtained after manual vortexing was 19.75 X 10*

Moreover, comparison of the bacterial concentration

of both devices. Bacteriologic process-

present in the bronchial secretions (K

pneumoniae

ing of the bronchial secretion samples collected after

1.4xlO

having passed the catheters through a contaminated

present in the Ringers solution-containing vials (Table

bronchoscope grew the marker organism in pure

3) suggested that, with either method of vortexing,

culture with either type of catheter. Whatever the

approximately 0.001 ml of bronchial secretions were

bacterial species we had chosen for fiberscope contam-

released into the vial.

8

CFU/ml) to the bacterial

concentrations

ination, no trace of this contaminating organism was In vivo Study

found (Table 1 and 2). With either catheter, the mean bacterial concentra-

The results of the in vivo study are reported in

tion of the marker organism in the vial containing the

Table 4. In the 15 of 18 patients with a positive culture,

Ringers solution was a 1,000-fold dilution of the

there was no difference in the types of bacterial species

bacterial concentration present in the bronchial secre-

isolated, but the concentration sometimes varied

tions to which the brushes were exposed. This fact

slightly. In nine patients, samples obtained with both

suggested that approximately 0.001 ml of bronchial

devices were sterile. (In seven of these nine patients,

secretions were released into the vial.

the final diagnosis, obtained either by bronchoalveolar lavage or by biopsy, was: Pneumocystis

Table 2—Results of Bacterial Culture of Bronchial Secretion Samples Collected with Both Types of Catheters In V i t r o

pneu-

vasive pulmonary aspergillosis [two], and atelectasis due to carcinoma [two]. In two cases, antibiotic therapy

Bacteria

CAL Catheter Bacterial count (CFU/ml)

M E D I Catheter Bacterial count (CFU/ml)

K pneumoniae K pneumoniae K pneumoniae K pneumoniae K pneumoniae K pneumoniae K pneumoniae

8.8x10* 7.27x10* 8.2x10* 7x10* 7.9x10* 8.3 x 10* 8.1 x 10*

8x10* 7.9x10* 8X10* 7.2X10*

7.7x 10* 8x10* 8.2x 10*

Bacterial count performed on the vial containing Ringer's solution in which the brushes had been vortexed. Contaminating organism was P aerugenisa (10 CFU/ml) Marker organism was K pneumoniae (8.10 CFU/ml) 7

7

748

carinii

monia [one], cytomegalovirus pneumonia [two], in-

had not been discontinued.) A sterile sample was never contradicted by a positive sample collected with the other device. Statistical analysis of results did not show significant differences in the types of bacterial species. In three patients (2, 3, and 15), there was no difference in bacterial species recovered by the two devices; however, additional bacteria were found either in very low concentrations or in concentrations with no pathogenic value, rendering these discrepancies clinically insignificant. As demonstrated in the in vitro experiments, the concentrations of bacteria reported are relevant to the collection medium and must be multiplied by 10 Diagnosis of Pulmonary Infections (Marquette

3

et al)

Table 4—Quantitative Bacterial Culture of Bronchial Secretion Samples Recovered with Both Types of Catheters

In Vivo

Patient No. 1 2

3

P stutzeri A calcoalecticus P maltophila P aeruginosa S aureus

4

E cloacae

5 6

A calcoalecticus P aeruginosa P aeruginosa S aureus

7

8 9 10 11 12 13 14 15

16 17

18 19 20 21 22 23 24 25 26 27

Bacterial count (CFU/ ml)

Bacterial species collected with CAL catheter

M E D I catheter

Bacterial count (CFU/ ml)

P stutzeri A calcoalecticus

10 10

10 10 10 10

S aureus S pneumoniae E cloacae A calcoalecticus P aeruginosa P aeruginosa

10 10 10 10 10

10 10 10 10 10 10 10 10 10 10

S aureus K pneumoniae S marcescens P mirabilis E coli S aureus A xylosoxydans E coli S aureus M morgani

10 10' 10' 10 10

4

2

1

1

2

1

3

2

2

3

K pneumoniae S marcescens P mirabilis E coli S aureus

5

s

1

3

1

A xylosoxydans E coli S aureus M morgani

1

3

3

2

Nonhemolytic strep E coli S epidermidis S aureus Enterococcus

10 10 10 10 10 10 10

2

2

l

3

2

S marcescens S aureus Nonhemolytic strep H parainfluenze S marcescens S marcescens K pneumoniae E coli P aeruginosa S pneumoniae No growth No growth No growth No growth No growth No growth No growth No growth No growth

Bacterial species collected with

1

4

w

10 10* 10 10 10 10 10

10

2

2

1

3

2

2

£ coli S epidermidis S aureus Enterococcus

10 10 10 10' 10 10' 10' 10' 10 10 10 10 10' 10 10

S marcescens S aureus Nonhemolytic strep

10 10 10

S marcescens S marcescens K pneumoniae E coli P aeruginosa S pneumoniae No growth No growth No growth No growth No growth No growth No growth No growth No growth

10 10 10 10 10' 10

Nonhemolytic strep

3

5

5

2

2

2

2

2

3

2

2

3

3

3

4

3

2

1

2

4

4

3

2

2

to obtain the actual bacterial concentration in bronchial secretions. DISCUSSION

The catheter B F W 10/70/90 (Medi-tech Corp) is a suitable device for protected bronchial sampling. It has been used with success in both intubated and nonintubated patients for bacterial diagnosis of community and hospital-acquired pneumonias. " In a canine model of Streptococcus pneumoniae pneumonia, BPCB was even more reliable than transtracheal 23

32

aspiration. Nevertheless, the cost of this telescoping catheter brush prohibits its routine use. It was this factor that led us to devise a catheter that was easier to use, potentially reusable and less expensive. All too frequently the single sheathed nonplugged catheter obtains contaminated specimens and therefore cannot be used for the purpose of bacterial diagnosis. A single-sheathed, nonplugged catheter had been tested by Wimberley et al in their original work. The singlesheathed catheter with an Agar plug was contaminated in 12 of 13 samplings, and the single catheter with a Gelfoam plug was contaminated in 5 of 13 samplings. Our results, using our new device, differ, in that no catheter contamination occurred. This can be explained for two reasons: 1) the plug is not ejected by advancing the brush, but by an air flux provided by the syringe; 2) the plug is placed just before performing the bronchoscopy which avoids drying and cracking of the plug due to aging. In addition, with this new catheter, we found the same results as Wimberley et al regarding the amount of bronchial secretions collected by the brush (0.001 ml). 24,25

23

Since manual vortexing of the brush in the Ringers solution is as valid as mechanical vortexing, cutting the brush off into the Ringers solution does not appear to be mandatory. In vivo results confirm the efficiency of our device and no significant difference between the two devices appears in either bacterial species or in concentrations of the bacteria. However, though oropharyngeal contamination is avoided by these sampling methods, bacterial colonizations of the lower respiratory tract remains to be distinguished from infection, especially in patients with obstructive endobronchial lesions, chronic bronchitis, bronchiectasis, or in intubated patients. Each of these conditions, theoretically, can be associated with heavy bacterial colonization of the lower respiratory tract. Therefore, quantitative bacteriology has been recommended to separate colonization from i n f e c t i o n . In patients without endobronchial structural abnormalities, it has been suggested that a colony count of greater than 10 CFU/ml could be used as an interpretative breakpoint, thus determining the significance of an isolate. However, in patients with chronic obstructive pulmonary disease or in intubated or ventilated patients, the bronchial tree may be heavily colonized and in these situations, a colony count, diagnostic of bacterial infection of the lower respiratory tract, remains to be well-defined. This factor indicates a need for further studies, studies for which our catheter, described here, may be particularly suitable. 30

34,35

303637

3

The distinct advantages of this new reusable catheter are that it simplifies uncontaminated, bronchial secretion collection and reduces, by 80 percent, its cost. It is this economic feature, an important consideration CHEST / 93 / 4 / APRIL, 1988

749

in these times of cost-consciousness in medical care, coupled with the device's proven practical success, that will make its widespread, routine use a possibility. A C K N O W L E D G M E N T : We are indebted to Mrs. M. O. Laurier and to Ms. L. Bater for technical assistance in this study.

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20 Spencer DC, Geaty MN. Complication of transtracheal aspiration. N Engl J Med 1972; 286:304 21 Unger KM, Moser KM. Fatal complication of transtracheal aspiration. Arch Intern Med 1973; 132:437-39 22 Bartlett JG, Alexander J, MayhewJ, Sullivan-Sigler N, Gorbach JL. Should fiberoptic bronchoscopy aspirates be cultured? Am Rev Respir Dis 1976; 114:73-8 23 Wimberley N W Faling LJ, Bartlett JG. A fiberoptic bronchoscopy technique to obtain uncontaminated lower airway secretions for bacterial culture. Am Rev Respir Dis 1979; 119:337-43 24 Hayes DA, McCarthy LC, Friedman M. Evaluation of two bronchofiberscopic methods of culturing the lower respiratory tract. Am Rev Respir Dis 1979; 119:319-23

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7 Murray PR, Washington JA. Microscopic and bacteriologic analysis of sputum. Mayo Clin Proc 1975; 50:599-644 8 Gekler RW, Gremillion DH, McAllister CK, Ellenhogen C. Microscopic and bacteriological comparison of paired sputa and transtracheal aspirates. J Clin Microbiol 1977; 6:396-99 9 Bartlett JG, Finegold SM. Bacteriology of expectorated sputum with quantitative culture and wash technique compared to transtracheal aspirates. Am Rev Respir Dis 1978; 117:1019-27 10 Wong LK, Barry AL, Horgon SM. Comparison of six different criteria for judging the acceptability of sputum specimens. J Clin Microbiol 1982; 16:627-31 11 Perlino CA. Laboratory diagnosis of pneumonia due to Streptococcus pneumoniae. J Infect Dis 1984; 150:139-44 12 Courcol RJ, Damien JM, Ramon P, Voisin C, Martin G. Presence of alveolar macrophages as a criterion for determining the suitability of sputum specimens for bacterial culture. Eur J Clin Microbiol 1984; 3:122-25 13 Palmer DL. Laboratory diagnosis of Streptococcus pneumoniae pneumonia. J Infect Dis 1985; 151:378 14 Pecora DV A method of securing uncontaminated tracheal secretions for bacterial examination. J Thorac Surg 1959; 37: 653-54 15 Kalinske RW, Parker RH, Brandt D, Hoeprich PD. Diagnostic usefulness and safety of transtracheal aspiration. N Engl J Med 1967; 276:604-08 16 Davidson M, Tempest B, Palmer DL. Bacteriologic diagnosis of acute pneumonia. Comparison of sputum, transtracheal aspirates and lung aspirates. JAMA 1976; 235:158-63 17 Bandt PD, Blank N, Castellini RA. Needle diagnosis for pneumonitis. JAMA 1972; 220:1578-80 18 Mimica I, Donoso E, Howard JE. Lung puncture in the ethnologic diagnosis of pneumonia. Am J Dis Child 1971; 122:278-82 19 Palmer DL, Davidson M, Lusk R. Needle aspiration of the lung in complex pneumonias. Chest 1980; 78:16-21

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28 Villers D, Derrienic M, Raffi F, Germaud P Baron D, Nicolas F, et al. Reliability of the Bronchoscopic protected catheter brush in intubated and ventilated patients. Chest 1985; 88:52730 29 Vereen L, Smart L M , George RB. Antibody coating and quantitative cultures of bacteria in sputum and bronchial brush specimens from patients with stable chronic bronchitis. Chest 1986; 90:534-36 30 Pollock H M , Hawkins EL, Bonner JR, Sparkman T, Bass JB. Diagnosis of bacterial pulmonary infections with quantitative protected catheter cultures obtained during bronchoscopy. J Clin Microbiol 1983; 7:255-59 31 Baughman RP Thorpe JE, Staneck J, Rashkin M, Frame PT Use of the protected specimen brush in patients with endotracheal or tracheostomy tubes. Chest 1987; 91:233-36 32 Higuchi JH, Coalson JJ, Johanson WG. Bacteriologic diagnosis of nosocomial pneumonia in primates. Usefulness of the protected specimen brush. Am Rev Respir Dis 1982; 125:53-7 33 Moser KM, Maurer J, Jassy L, Kremsdorf R, Konopka R, Shure D, et al. Sensitivity, specificity, and risk of diagnostic procedures in canine models of Streptococcus pneumoniae pneumonia. Am Rev Respir Dis 1982; 125:436-42 34 Johanson WG, Pierce AK, Sanford JP Thomas GD. Nosocomial respiratory infections with gram negative bacilli. The significance of colonization of the respiratory tract. Ann Intern Med 1972; 77:701-06 35 Borderon E, Leprince A, Gueveler C. Valeur de l'examen bacteriologique quantitatif des secretions tracheales chez les malades dun service de reanimation. Med et Mai Inf 1980; 10:478-86 36 Winterbauer RH. Diagnosis of bacterial pneumonia with fiberoptic bronchoscopy. Eur J Clin Microbiol 1985; 4:95-7 37 Winterbauer RH, Hutchison JF, Reinhardt GN, Sumida SE, Dearden B, Thomas CA, et al. The use of quantitative cultures and antibody coating of bacteria to diagnose bacterial pneumonia by fiberoptic bronchoscopy. Am Rev Respir Dis 1983; 128:98103

Diagnosis of Pulmonary Infections (Marquette

et al)