.
`
`United States Patent [19]
`Markus
`
`US005407807A
`
`[11] Patent Number:
`[45] Date of Patent:
`
`5 407 807
`9
`9
`Apr. 18, 1995
`
`[54] METHOD AND APPARATUS FOR
`DETECI‘ING SEPSIS CAUSATION IN A
`CATHETER
`[75] Inventor‘
`stimley 1" Markus’ oconomowoc,
`Wls- _
`[73] Assignee: Daymark Medical Industries, Inc.,
`Pewaukee, Wls-
`[21] APPL Na; 51,420
`_
`[22] F1led:
`Apr. 23, 1993
`[51] Int. Cl.6 ...................... .. C12Q 1/04;
`
`L256
`
`[52] US. 01. ................................... .. 435/34; 15/104.2-
`128/756. 435/31. 435/294;
`-
`’
`’
`.
`[58] Field of Search ........................ .. 15/ 104.05, 104.2,
`128/749, 756’ 759. 422/294. 435/31, 34’ 294,
`’
`’
`295
`
`[56]
`
`References Cited
`U_S_ PATENT DOCUMENTS
`
`Cooper ------------ .7 ................ u
`4’235’244 11/1980 Abele “““ "
`" 128/749
`4,368,272 1/1983 Kashket
`.. 435/293
`4,397,945 8/1983 Lemonnier
`435/31
`4,485,824 12/1984 K011 ............ ..
`.. 128/756
`5,091,316 2/1992 Monthony .......................
`435/295
`
`5,240,675 8/1993 Wilk .................................... .. 422/22
`5,260,020 11/1993 Wilk .................................... .. 422/22
`OTHER PUBLICATIONS
`Markus Stan, Buday, Stephen, “Culturing Indwelling
`Central Venous Catheters in Situ,” Infections in Surgery,
`May, 1989 pp- 157-162‘
`Primary Examiner—Michael G. Wityshyn
`Assistant Examiner-Ralph Gitomer
`Attorney, Agent, or Firm-Blakely, Sokoloff, Taylor,
`Zafman
`[57]
`
`ABSTRACT
`
`A method and an 11PMratus is disclosed for detecting
`whether a catheter is the cause of an infection in a pa
`tient without removing the catheter from the patient.
`The method for detecting an infection in a catheter
`including the steps of inserting a wire having a brush on
`the end, removing the brush and culturing ?brin which
`may have accumulated on the inside of the catheter and
`outside the end of the catheter to determine if any infec
`tious microorganisms are captured in the ?brin. The
`brush has bristles of a longer
`to extend through
`the end of the catheter and shorter bristles to sam 1e
`.
`.
`’
`p
`the mslde of the catheter
`
`10 Claims, 6 Drawing Sheets
`
`

`

`US. Patent
`US. Patent
`
`Apr. 18, 1995
`Apr. 18, 1995
`
`Sheet 1 of 6
`Sheet 1 of 6
`
`5,407,807
`5,407,807
`
`
`
`

`

`US. Patent
`
`Apr. 18, 1995
`
`Sheet 2 of 6
`
`5,407,807
`
`FIG. 3
`
`PROVIDING DEWCE FOR COLLECTTNG HBR/N
`
`1
`
`INSERT/NO DEWOE INLET OF CATHETER
`
`MOVING DEWCE TOWARD THE END OF
`CATHETER UNTTL THE LARGE RAD/US BRUSH
`PORTTON PROTRUDES THROUGH THE END
`
`1
`
`W/THDRAW/NG DEVICE FROM CATHETER,‘
`OBTAIN/NO SAMPLE OF fTBR/N TRON
`CATHETER UNINO AND OUTER END
`
`CUL TUR/NO SAMPLE
`
`L STOP )
`
`

`

`US. Patent
`
`Apr. 18, 1995
`
`Sheet 3 0f 6
`
`5,407,807
`
`FIG. 4
`
`(START)
`
`SELECT/NC PROPERLY SIZED DEWCE
`FOR COLLECTING SAMPLE
`
`I
`DISCONNECTTNC CATHETER FROM INTRAVENOUS SUPPLY
`
`T
`STERILIZINO INLET END OF CATHETER
`
`INSERTTNC DEVICE THROUGH INLET END OF CATHETER
`
`T
`
`MOWNC DEVICE TO OUTLET END OF
`CATHETER SO TT-MT END BR/STLES STICK
`OUT OF CATHETER END
`
`WITHDRAWING DEVICE FROM CATHETER,‘
`OBTAIN/NC SAMPLE OF FTBRIN WITH
`POSSIBLE INFECTIOUS MlCROORCAN/SMS
`
`1
`RECONNECT CATHETER TO INTRAVENOUS SUPPLY
`
`RES TARTTNC INTRAVENOUS SUPPLY
`
`CULTURE SAMPLE AND IDENTTFY ANY
`INFECTTOUS MICROORGAN/SMS
`
`< STOP }
`
`

`

`US. Patent
`US. Patent
`
`Apr. 18, 1995
`Apr. 18, 1995
`
`Sheet 4 of 6
`Sheet 4 of 6
`
`5,407,807
`5,407,807
`
`M»,
`Mm,
`
`__
`.5;
`H mm,
`
`Vm,
`
`NM\a
`
`\Om,
`
`Vm,
`
`
`

`

`U.S. Patent
`US. Patent
`
`Apr. 18, 1995
`Apr. 18, 1995
`
`Sheet 5 of 6
`Sheet 5 0f 6
`
`5,407,807
`5,407,807
`
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`U.S. Patent
`US. Patent
`
`Apr. is, 1995
`Apr. 18, 1995
`
`sheet 6 of 6
`Sheet 6 of 6
`
`5,407,807
`5,407,807
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`

`1
`
`5,407,807
`
`METHOD AND APPARATUS FOR DETECTING
`SEPSIS CAUSATION IN A CATHETER
`
`5
`
`15
`
`25
`
`30
`
`2
`sterile velvet material that is contacted with the teeth
`and then cultured.
`Another prior art test method and apparatus for test
`ing whether there is any infectious material in the con
`tents in syringe is described in US. Pat. No. 4,397,945,
`which teaches the use of a sampling device for sampling
`a portion of the contents of the syringe.
`Also in the prior art are cytology brushes which are
`used to collect cells for analysis. It is not believed that
`such a brush has heretofore been used for a sampling
`system for microbial infection.
`Another prior art method previously developed by
`the present inventor is described in a publication enti
`tled Markus, Stan and Buday, Stephen, “Culturing In
`dwelling Central Venous Catheters In Situ,” Infections
`in Surgery, May 1989, pp. 157-160, and a review article
`Beam, Thomas, “Vascular Access, Catheters and Infec
`tions,” Infections in Surgery, May 1989, pp. 156;
`161-162. The Markus, et al. article teaches a method
`and apparatus for assessing whether central venous
`catheters is causing catheter sepsis in situ. The appara
`tus comprises a thin wire with either a stop or separate
`handle on or near one end, and a brush at the other end.
`The apparatus is speci?cally designed so that it cannot
`protrude through the end of the catheter. The brush is
`designed to ?t the exact length of the catheter in situ,
`and a metal stopper ensures that the brush does not go
`beyond the catheter tip and does not damage the vein
`wall during sampling. (See FIG. 2 at p. 158).
`Thus, there is a need for a better method and appara
`tus for determining the existence of infections being
`caused by an indwelling catheter, which method and
`apparatus do not have the drawbacks of the prior art.
`
`BACKGROUND OF THE INVENTION
`1. FIELD OF THE INVENTION
`The present invention relates to a method and an
`apparatus for detecting whether a catheter is the cause
`‘of sepsis in a patient without unnecessarily removing
`the catheter from a patient.
`2. ART BACKGROUND
`For a number of years, central venous catheters have
`been used widely in medicine in the critical care area.
`These catheters are commonly used to perform a num
`ber of different, but equally important functions, among
`which include (a) measuring central pressure; (b) moni
`toring and modifying ?uid volume; (0) administering
`one or more therapeutic substances simultaneously; (d)
`providing a secure site of intravenous (“IV”) access;
`and (e) conducting blood therapy. Furthermore, these
`catheters also are used in long-term treatment, such as
`chemotherapy and parenteral nutrition (so called
`“Hickman catheter”).
`Venous catheters are inserted into a patient “periph
`erally” through a cephalic or basilic vein, or “centrally”
`through the internal jugular, external jugular, subclav
`ian or saphenous vein. Determining which type of inser
`tion is based on many factors; however, any type inser
`tions typically causes at least some discomfort and pain
`to the patient, and requires a reasonable amount of skill,
`and each insertion is subject to certain inherent risks and
`costs. In addition to venous catheters, there are also
`peritoneal catheters, urethral catheters, such as the
`Foley catheter, and arterial catheters _in the prior art.
`According to various studies, approximately 4—l5%
`of the venous catheters are the cause of secondary infec
`tions. On the average, in about 60% of the cases in
`which there is sepsis, the catheter cannot be ruled out as
`the cause, and the catheter is removed to make a deter
`mination if it is the cause, as described in more detail
`below. Even though only a small percentage of cathe
`ters are the cause of such infections, hospitals are re
`quired to continuously monitor catheters for possible
`catheter sepsis (i.e., infections within an indwelling line
`of a catheter) which may cause complications in a pa
`tient’s treatment leading to sickness or even death.
`The current diagnostic techniques used to detect
`catheter sepsis are problematic. If a physician or nurse
`suspects that an infection is being caused by the cathe
`ter, the suspect catheter is removed and replaced with a
`new catheter. The tip of the suspect catheter is removed
`under sterile conditions and sent to the lab for contami
`nation testing. If the catheter is found to be infected,
`physicians can provide treatment in accordance with
`standard medical procedures for such infection.
`This procedure, called a “tip culture”, offers a num
`ber of disadvantages. The primary disadvantage is that
`since only a small percentage of the catheters become
`infectious, patients quite often experience additional
`pain and discomfort due to the unnecessary removal of 60
`the catheters. Also, the insertion of a new catheter can
`be associated with additional risks of infection, such as
`bleeding, pneumothorax, and infection. Moreover, the
`removal of non'infected catheters contributes to rising
`medical costs.
`,
`One prior art method of identifying and locating
`dental microorganisms is disclosed in US. Pat. No.
`4,368,272 comprising a ?exible strip of material with a
`
`65
`
`35
`
`40
`
`45
`
`50
`
`55
`
`SUMMARY OF THE INVENTION
`A method and apparatus are disclosed which over
`come the disadvantages and limitations associated with
`prior art tip culture testing techniques used to detect the
`presence of infections within the indwelling line of the
`catheter.
`It is the object of the present invention to provide a
`method and an apparatus for detecting whether an in
`fectious microbiological culture is present Within an
`indwelling line of a catheter without removing the cath
`eter from the patient.
`It is also an object of the present invention to provide
`a method and an apparatus which would greatly reduce
`morbidity caused by an infection within a catheter by
`allowing physicians and nurses to easily monitor the
`suspect catheter.
`It is a further object of the present invention to pro
`vide a cost-efficient method and apparatus for detecting
`an infection Within a catheter without unnecessary re
`moval and subsequent disposal of the catheter.
`It is also an object of the present invention to avoid
`unnecessary pain and discomfort to a patient caused by
`removing a suspect catheter and replacing it with a new
`catheter.
`These and other objects of the present invention are
`provided in a method and an apparatus for detecting an
`infection within a catheter without removing the cathe
`ter from the patient. The present invention provides a
`method for detecting an infection in a catheter compris
`ing the steps of (i) supplying a specimen collection
`means adapted to ?t within the interior of a catheter and
`collect any infectious microorganisms from the inside as
`well as the exterior of the end of the catheter; (ii) insert
`
`

`

`3
`ing said specimen collection means into said catheter to
`collect said microorganisms disposed with the catheter
`and the outside of the tip of the catheter; (iii) advancing
`said specimen collection means through said catheter
`towards the end of said catheter within the vein to a
`point where a portion of the specimen collection means
`passes through the end of the catheter and contacts the
`outer end of the catheter in order to sample the outside
`of the catheter as well as the inside; (iv) removing said
`specimen collection means from said catheter under
`sterile conditions so that a microbial specimen may be
`obtained on said specimen collection means; and (v)
`culturing said specimen to determine whether infectious
`microorganisms are present and identify the same.
`The specimen collection means collects ?brin which
`may be coating inside and outside the tip of the catheter,
`the ?brin having mixed therein microbes which may
`then be cultured and identi?ed. The ?brin along with
`the captured microbial sample can be plated under ster_
`ile conditions which are commonly known in the art
`and the cultures which may grow from the sample can
`be identi?ed by known microbiological techniques.
`Further, in one embodiment, the apparatus comprises
`a loop handle, and means for collecting said specimen
`within a catheter. The means for collecting said speci
`men is preferably a brush made of thin synthetic bristles.
`The length of the bristles is greater for the bristles at the
`end of the brush so that they protrude out the end of the
`catheter to take a sample outside the end of the catheter.
`The tip of the brush is blunted, rounded or otherwise
`dulled so that if it contacts the wall of the vein it does
`not damage the vein wall (or the wall of any other tissue
`which it may contact if used with other types of cathe
`ters.) The handle consists of a twisted wire loop in a
`manner so that the apparatus is advanced through the
`catheter a limited amount and prevented from passing
`through the catheter and beyond the proximal end. This
`prevents any chance of fragmentation with loss of brush
`within the catheter or vein.
`The present apparatus can be used with a number of
`40
`diferent types of catheters including indwelling venous
`catheters, Foley catheters, Hickman catheters, paren
`teral catheters, arterial catheters and the like.
`
`20
`
`25
`
`30
`
`5 ,407, 807
`
`4
`FIG. 9 is a side schematic view of the catheter and
`brush of FIG. 7, where the brush is fully inserted into
`the catheter.
`FIG. 9a is a left end view of the brush and catheter of
`FIG. 9.
`FIG. 10 is a side schematic view of the catheter and
`brush of FIG. 7, where the brush is being removed from
`the catheter.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`A method and an apparatus are described which are
`useful in detecting whether a catheter is causing an
`infection in a patient. The preferred embodiment of the
`present invention might best be described as an unique
`method for detecting an infection within a catheter
`through use of an apparatus (hereinafter referred to as a
`“culturing brush”), so that removal of the suspect cathe
`ter from a patient is not necessary unless it is determined
`that the catheter is the cause of the patient’s infection.
`Such method and apparatus eliminates many disadvan
`tages associated with using the conventional tip culture
`method for testing for infections within an indwelling
`line of a catheter. It should be borne in mind that the
`present invention need not be limited in use for central
`venous catheters, but may ?nd wide application for
`testing any ?uid conveying channel.
`FIG. 1 shows an embodiment of a prior art central
`venous catheter. The catheter comprises a central line/
`connected to a ?exible hub 2. The central line is a tubu
`lar structure with an inlet 3 at the proximal end, con
`nected to the ?exible hub 2 and at least one outlet 4
`located at the distal end 5 of the central line 1. In FIG.
`1, there are three outlets labeled 4a, 4b and 4c in which
`therapeutic ?uids are passed through and injected into a
`patient’s vein. A plurality of lumen extension tubes,
`shown as 5a, 5b and 5c, provide a connection between
`an intravenous supply 7 and the ?exible hub 2 to allow
`therapeutic ?uids to be given to a patient intravenously.
`Referring now to FIG. 2, a prior art embodiment of a
`culturing brush described in the above-referenced Mar
`cus, et al. article is illustrated. The culturing brush 10
`has an overall length of 18 centimeters (“ems”) with a
`tolerance of 0.50 cm. The brush tip 12 included a stem
`13 and a plurality of bristles 14 and end 11. The stem 13
`was a stainless steel wire having a diameter of 0.010 in.
`The plurality of bristles 14 protrude radially out from
`the stem 13 to collect the ?brin deposited on an inner
`surface of an indwelling line of a catheter. Each of the
`plurality of bristles is made of nylon material, such as
`Tynex ®, or other suitable bristle material, and has a
`diameter of about 0.005 in.. The overall brush has a
`diameter of 5 mmi0.5 mm and a length of 13 mmil
`mm. The brush stem 13 extends through a spring sheath
`16 and is bonded into a handle 15.
`FIG. 5 is the presently preferred embodiment of the
`present invention comprising a ?exible stainless steel
`twisted wire 20 having a brush 22 on one end and a loop
`handle 24 made of the untwisted portion of the stainless
`steel on the other end. The end 21 is blunted or rounded
`for safety. In this embodiment, the preferred dimensions
`include the diameter of the wire being 0.038 in
`chesi0.003 inches, the overall length being l2, 14 or 18
`inches, depending upon the size of the catheter in which
`it is used, and the bristles may be 0.003 Tynex, but are
`preferably 0.0025 inch width nylon. The longer bristle
`25 display a 3 mm diameter D, and extend along the
`length of the brush for about 2 mm. The shorter bristles
`
`45
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`The objects of the present invention will be described
`with respect to the following ?gures in which:
`FIG. 1 is an illustration of a central venous catheter in
`the prior art.
`FIG. 2 is a sectioned view of a prior art embodiment
`of the ?brin sampling device of the prior art.
`FIG. 3 is a ?owchart illustrating a method for deter
`mining the existence of an infection by sampling inside
`the catheter and outside the tip of a catheter.
`FIG. 4 is a more detailed ?owchart of the method for
`testing the existence of an infection by sampling inside
`the catheter and outside the tip of a catheter.
`FIG. 5 is a side view of an alternative embodiment of
`a microbiological ?brin sampling brush of the present
`invention.
`60
`FIG. 6 is a side view of an alternative embodiment of
`a microbiological ?brin sampling brush of the present
`invention.
`FIG. 7 is a side view of the embodiment of FIG. 5 and
`a schematic view of a catheter.
`FIG. 8 is a side schematic view of the catheter and
`brush of FIG. 7, with the brush being inserted into the
`catheter.
`
`65
`
`55
`
`

`

`5,407,807
`5
`6
`26 have a diameter D’ of 1.5 mm and extend along the
`to lessen the resistance of said culturing brush. The
`length of the brush for about 6 mm for a total length of
`third step is to swab the ?exible hub of the catheter with
`brush of about 8 mm. Another way of describing the
`alcohol in order to sterilize the catheter before inserting
`length of the bristles is that the longer bristles are of
`the brush (Step 3). Thereafter, follow Steps 2-5 as
`sufficient length that their effective diameter (the appar
`shown in FIG. 3, but before culturing the brush tip,
`ent diameter when viewing the longer bristles from the
`reconnect the catheter to the intravenous supply and
`end) is greater than the diameter of the catheter, or
`restart the intravenous ?uids (Steps 4-8).
`another way, is that the length of any such bristle is
`The method is also demonstrated in FIGS. 7-10.
`longer than the radius of the catheter. The shorter bris
`FIG. 7 shows a brush 40 and catheter 42 in generally
`tles have an effective diameter approximating the inner
`schematic form. FIG. 8 shows the brush 40 being in
`diameter of the catheter, or another way to describe it,
`serted into the catheter 42 in the direction A depicted
`is that the length of the shorter bristles is approximately
`by the arrow. It is noted that the larger bristles 44 are
`the inner radius of the catheter.
`folded and the smaller bristles 46 are sized to generally
`FIG. 6 is yet another embodiment of the present
`touch the inside surfaces of the catheter. As shown in
`invention comprising a ?exible stainless steel twisted
`FIG. 9, the larger bristles 44 are outside the end 48 of
`wire 30 having a brush 32 on one end 31, which is
`the catheter 42, and the handle 49 of the brush 40 is
`rounded, and a stop means 34 made of stainless steel, to
`abutting the other end 43 of the catheter, preventing the
`stop the brush from passing too far through the cathe
`brush from being pushed further through the catheter.
`ter. Again, the brush 32 is made up a a longer bristle
`In this position, the larger bristles 44 can sample the
`section 33 and a shorter bristle section 35.
`outer portion of the end 48 of the catheter 42. As shown
`Additional lengths of the device may be required for
`in FIG. 10, the brush 40 is then removed from the cathe
`different lengths of catheters. For a standard indwelling
`ter in direction A’, taking with it a sample of ?brin from
`venous catheter, lengths of 15, 20 and 30 cms are re
`the outer surface of the end catheter as well as from the
`quired. For a standard Hickman catheter, a length of 36
`inner surface of the catheter. FIG. 9a shows an end
`inches is required. It will be obvious to a person of
`view of the catheter and brush of FIG. 9, and particu
`25
`ordinary skill in the art to modify the length, and adapt
`larly, the handle 49, the catheter 42, the larger bristles
`the brush diameter to accommodate various catheter
`44 outside the catheter, and the smaller bristles 46 inside
`sizes as required.
`the catheter.
`FIG. 3 illustrates procedure for determining whether
`If it is determined that infectious microbes are present
`an infection exists in the indwelling of the central line of
`in the culture, the catheter can then be removed and
`the central venous catheter. The ?rst step is to obtain
`replaced, and the microbes can be identi?ed, and the
`the culturing brush as illustrated in FIGS. 5 or 6 (Step
`patients treated with the requisite antibiotics or the like.
`1). A brush of the proper size must be selected so that
`If it is determined that there is no infection, there is no
`the brush can be advanced to, and just through the tip of
`need to remove the catheter, and other sources of the
`the catheter. The patient is then prepared and draped,
`infection can be explored.
`and the physician gloved with sterile gloves. The IV is
`The apparatus described herein may be manufactured
`then disconnected. Next the distal end of the catheter is
`by many different materials and many different sizes.
`sterilized. Next, the culturing brush is inserted into the
`For example, the device can be manufactured as a single
`?exible hub of the catheter (Step 2). By applying force
`unit or as a plurality of units coupled together. More
`to the culturing brush, the brush tip passes through an
`over, it can be made of stainless steel, plastic or any
`inlet of the indwelling central line towards the tip of the
`other material which can be sterilized.
`catheter (Step 3). As a result, the plurality of bristles of
`While the method and apparatus have been described
`the brush tip come into contact with the inner surface of
`in terms of various embodiments, other embodiments
`the indwelling line of the catheter. As the brush tip
`may come to mind to those skilled in the art without
`approaches the tip of the catheter, the handle permits
`departing from the spirit and scope of the present inven
`the brush tip to just protrude through the tip of the
`tion. The invention should, therefore, be measured in
`catheter because the diameter of the handle is larger
`terms of the claims which follow.
`than the diameter of the catheter end. In the embodi
`What I claim is:
`ments shown in FIGS. 5 and 6, the loop handle 24 and
`1. A method for detecting whether a catheter is the
`the stop means 34 serve the same purpose at the end of
`cause of an infection, said catheter having an inner
`the catheter. Thereafter, the brush is removed from the
`surface and an inlet at one end of said catheter and at
`indwelling line of the catheter (Step 4) bringing with it
`least one outlet at the other end of said catheter, said
`a sample of ?brin collected on the interior wall of the
`method comprising the steps of:
`catheter and the outer tip of the catheter, said ?brin
`providing a means for collecting ?brin, said means for
`having captured within it a sampling of any microbio
`collecting ?brin comprising a ?rst end and a sec
`logical contamination which may exist in the catheter.
`ond end, a brush disposed at said ?rst end of said
`The brush tip is then cultured by applying the brush to
`collecting means, said brush having a section of
`a culture media under sterile conditions (Step 5). Alter
`longer bristles having an effective diameter greater
`natively, the brush is secured in a sterile container and
`than the diameter of the catheter disposed at said
`sent to a laboratory for culturing; The IV is then recon
`?rst end of said collecting means and a section of
`nected and restarted.
`shorter bristles disposed adjacent to said section of
`Referring to FIG. 4, another embodiment of the pres
`longer bristles and closer to the second end than
`ent invention is illustrated. The ?rst step is to obtain the
`the longer bristle section;
`culturing brush (Step 1). Next, unhook a catheter from
`inserting said means for collecting ?brin through said
`an intravenous supply so that the culturing brush can be
`inlet of said catheter;
`inserted within said indwelling line with the brush tip
`advancing said means for collecting ?brin toward
`inserted ?rst (Step 2). It may be helpful, but is not re
`said at least one outlet until said longer bristles
`quired, that the line be held in a straight angle in order
`extend through the other end of the catheter;
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`15
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`5,407,807
`7
`8
`removing said means for collecting ?brin from said
`longer bristle section and disposed closer to the
`second end than the longer bristle section;
`catheter and taking a sample of ?brin from the
`disconnecting said one end of said catheter from an
`inner surface of said catheter; and
`intravenous supply;
`culturing the sample collected on said means for col
`inserting said brash means through said inlet of said
`lecting ?brin to determine whether any infectious
`catheter;
`microbes were disposed in said ?brin.
`moving said brush means from said inlet toward said
`2. The method according to claim 1 further compris
`at least one outlet until the longer bristle section
`ing identifying said infectious microbes. I
`extends through said at least one outlet;
`3. The method according to claim 1 wherein if an
`removing said apparatus from said catheter, taking
`infection is detected, the catheter is removed.
`with said brush means a sample of ?brin disposed
`4. The method according to claim 1 wherein said
`on the inside of said catheter;
`longer bristles have an effective diameter of approxi
`reconnecting said one end of said catheter to said
`intravenous supply;
`mately 3 mm and said shorter bristles have an effective
`restarting said intravenous supply; and
`diameter of about 1.5 mm.
`culturing said ?brin sample to detect and identify any
`5. The method according to claim 1 wherein prior to
`microorganisms therein.
`inserting said means for collecting ?brin into said outlet,
`10. An apparatus for detecting whether a catheter is
`said catheter is disconnected from an intravenous sup
`the cause of an infection, said catheter having an inner
`ply-
`~
`surface and an outer surface with an inlet at one end of
`6. The method according to claim 1 wherein prior to
`said catheter and an outlet at an other end of said cathe
`inserting said means for collecting ?brin into said outlet,
`ter, said apparatus comprising:
`said proximal end of said catheter is sterilized.
`a sterile wire a ?rst end and a second end;
`7. The method according to claim 1 wherein said
`a handle connected to said second end of said wire;
`sample is cultured by plating said sample onto a culture
`and
`medium.
`means for collecting ?brin from said inner surface of
`8. The method according to claim 1 wherein said
`said catheter, comprising a brush disposed at said
`catheter is a Hickman catheter.
`?rst end of said wire, said brush having longer
`bristles at the ?rst end of said wire and shorter
`9. A method for detecting whether a catheter is con
`bristles adjacent thereto and closer to said second
`taminated and thereby is the cause of an infection, said
`end of said wire than the longer bristles, said longer
`catheter having an inner surface and an inlet at one end
`bristles having a length greater than the radius of
`of said catheter and at least one outlet at the other end
`the catheter, and said shorter bristles having a
`of said catheter, said method comprising the steps of:
`length approximately equal to the radius of the
`supplying an apparatus for collecting ?brin, said ap
`catheter;
`paratus comprising a ?exible, sterile wire having a
`said apparatus being sized to the length of the cathe
`?rst end and a second end, a brush means disposed
`ter so that when the handle abuts said one end of
`on said ?rst end of said wire, said brash means
`the catheter, the longer bristles extend through the
`having a longer bristle section at the ?rst end of
`other end of the catheter.
`said wire and a shorter bristle section adjacent the 40
`* * =l<
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`

`UNITED sTATEs PATENTAND TRADEMARK OFFICE
`CERTIFICATE OF CORRECTION
`
`: 5,407,807
`PATENTNO.
`:
`April 18, 1995
`DATED
`INVENTOR($) : Markus
`
`It is certified that error appears in the above-identified patent and that said Letters
`Patent is hereby corrected as shown below:
`
`In column 6 at line 67 "outlet" should be "outlet-w‘
`
`In column 7 at line 38 "brash" should be -—brush——;
`
`In column 8 at line 5 "brash" should be —-brush——.
`
`
`
`Signed. and Sealed Fourth Day of July, 1995
`
`Am.-
`
`' Mk
`
`Arresting Of?cer
`
`Commissioner of Patents and Trademarks
`
`BRUCE LEHMAN
`
`