US20160213294A1 - Systems and methods for parenterally procuring bodily-fluid samples with reduced contamination - Google Patents

Abstract

The present invention is directed to the parenteral procurement of bodily-fluid samples. The present invention is also directed to systems and methods for parenterally procuring bodily-fluid samples with reduced contamination from dermally-residing microbes. In some embodiments, a bodily-fluid withdrawing system is used to withdraw bodily fluid from a patient for incubation in culture media in one or more sample vessels. Prior to withdrawing bodily fluid into the one or more sample vessels for incubation, an initial volume of withdrawn bodily fluid is placed in one or more pre-sample reservoirs and is not used for the incubation in culture media.

Description

RELATED APPLICATIONS
• This application claims priority to U.S. Provisional Application Ser. No. 60/870,599, filed Dec. 18, 2006, the entire contents of which is incorporated herein by reference.
TECHNICAL FIELD
• The present invention is directed to the parenteral procurement of bodily-fluid samples. The present invention is also directed to systems and methods for parenterally procuring bodily-fluid samples with reduced contamination from dermally-residing microbes.
BACKGROUND
• Health care professionals routinely perform various types of microbial tests on patients using parenterally-obtained patient bodily fluids. Contamination of parenterally-obtained bodily fluids by microbes may result in spurious microbial test results. Spurious microbial test results may be a concern when attempting to diagnose or treat a suspected illness or condition. False positive results from microbial tests can cause a patient to be unnecessarily subjected to one or more anti-microbial therapies, such as anti-bacterial or anti-fungal therapies, which may cause anguish and inconvenience to the patient, as well as produce an unnecessary burden and expense to the health care system.
BRIEF DESCRIPTION OF THE DRAWINGS
• Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following drawings. In the drawings, like reference numerals refer to like parts throughout the various figures unless otherwise specified.
• For a better understanding of the present invention, reference will be made to the following Detailed Description, which is to be read in association with the accompanying drawings, wherein:
• FIG. 1 is a schematic view of one embodiment of a sample-procurement system, according to the invention;
• FIG. 2 is a schematic cross-sectional view of one embodiment of a first needle of a sample-procurement system inserted into a patient vein; according to the invention;
• FIG. 3A is a schematic view of one embodiment of a bodily-fluid withdrawing device draining blood from a patient vein into a pre-sample reservoir, according to the invention;
• FIG. 3B is a schematic view of one embodiment of a bodily-fluid withdrawing device draining blood from a patient vein into a sample vessel, according to the invention;
• FIG. 4A is a schematic view of another embodiment of a sample-procurement system with multiple sample vessels being used to drain blood from a patient to a pre-sample reservoir, according to the invention;
• FIG. 4B is a schematic view of the embodiment of the sample-procurement system shown inFIG. 4A being used to drain blood from a patient to a pre-sample reservoir with a splash guard positioned over the second needle, according to the invention;
• FIG. 5 is a schematic view of another embodiment of a sample-procurement system with a diversion mechanism in a bodily-fluid withdrawing device, according to the invention;
• FIG. 6A is a schematic close-up view of one embodiment of a diversion mechanism that includes a switchable valve in a first position, according to the invention;
• FIG. 6B is a schematic close-up view of the diversion mechanism shown inFIG. 6A in a second position, according to the invention;
• FIG. 7A is a schematic close-up view of a second embodiment of a diversion mechanism that includes two flow-control blocks in a first position, according to the invention;
• FIG. 7B is a schematic close-up view of the diversion mechanism shown inFIG. 7A in a second position, according to the invention;
• FIG. 8 illustrates a flow diagram showing one embodiment of exemplary steps used for procuring samples, according to the invention;
• FIG. 9 illustrates a flow diagram showing a second embodiment of exemplary steps used for procuring samples, according to the invention.
DETAILED DESCRIPTION
• The present invention is directed to the parenteral procurement of bodily-fluid samples. The present invention is also directed to systems and methods for parenterally procuring bodily-fluid samples with reduced contamination from dermally-residing microbes. In some embodiments, a bodily-fluid withdrawing system is used to withdraw bodily fluid from a patient for incubation in culture media in one or more sample vessels. Prior to withdrawing bodily fluid into the one or more sample vessels for incubation, an initial volume of withdrawn bodily fluid is placed in one or more pre-sample reservoirs and is not used for the incubation in culture media.
• Health care professionals routinely procure parenterally-obtained bodily-fluid samples (“samples”) from patients. Patient samples may include many different types of bodily fluids. For example, patient samples may include blood, cerebrospinal fluid, urine, bile, lymph, saliva, synovial fluid, serous fluid, pleural fluid, amniotic fluid, and the like.
• Patient samples are sometimes tested for the presence of one or more potentially undesirable microbes, such as bacteria, fungi, orCandida. Microbial testing may include incubating patient samples in one or more sterile vessels containing culture media that is conducive to microbial growth. Generally, when microbes tested for are present in the patient sample, the microbes flourish over time in the culture medium. After a pre-determined amount of time, the culture medium can be tested for the presence of the microbes. The presence of microbes in the culture medium suggests the presence of the same microbes in the patient sample which, in turn, suggests the presence of the same microbes in the bodily-fluid of the patient from which the sample was obtained. Accordingly, when microbes are determined to be present in the culture medium, the patient may be prescribed one or more antibiotics or other treatments specifically designed to remove the undesired microbes from the patient.
• Patient samples can sometimes become contaminated during procurement. Contamination of a patient sample may result in a spurious microbial test result which, in turn, may cause the patient to unnecessarily undergo one or more microbial-removal treatments. One way in which contamination of a patient sample may occur is by the transfer of dermally-residing microbes dislodged during needle insertion into a patient and subsequently transferred to a culture medium with the patient sample. The dermally-residing microbes may be dislodged either directly or via dislodged tissue fragments. The transferred microbes may thrive in the culture medium and eventually yield a positive microbial test result, thereby falsely indicating the presence of microbes in vivo.
• FIG. 1 is a schematic view of one embodiment of a sample-procurement system100. The sample-procurement system100 includes a bodily-fluid withdrawing device102, one or more pre-samplereservoirs104, and one or more culture-medium-containing sample vessels106 (“sample vessels”). InFIG. 1 (and in subsequent Figures), a single pre-samplereservoir104 is shown and represents either one pre-samplereservoir104 or a plurality ofpre-sample reservoirs104. Likewise,FIG. 1 (and subsequent Figures) shows asingle sample vessel106 that represents either onesample vessel106 or a plurality ofsample vessels106.
• The bodily-fluid withdrawing device102 includes a first sterile needle108 (“first needle”) and a second sterile needle110 (“second needle”) coupled to thefirst needle108. Thefirst needle108 includes adistal end112, aproximal end114, and a lumen (seeFIG. 2) extending from thedistal end112 to theproximal end114. Thedistal end112 is configured and arranged for puncturing through multiple layers of patient skin and theproximal end114 is configured and arranged for attachment with sterile, lumen-containing devices. The lumen (seeFIG. 2) is configured and arranged for passing bodily-fluids from thedistal end112 of thefirst needle108 to theproximal end114.
• Thesecond needle110 includes adistal end116 configured and arranged for puncturing septa disposed overpre-sample reservoirs104 andsample vessels106, aproximal end118 configured and arranged for attachment with other sterile, lumen-containing devices, and a lumen (not shown) extending from thedistal end116 to theproximal end118. Thefirst needle108 and thesecond needle110 can be manufactured using any rigid, sterilizable, biocompatible material suitable for penetrating the skin of a patient,septa122 disposed overpre-sample reservoir104, orsepta128 disposed oversample vessels106. Exemplary materials may include stainless steel, and the like. In at least some embodiments, thefirst needle108 and thesecond needle110 are selected from the Vacutainer™ blood collection set, manufactured by Becton Dickinson.
• In at least some embodiments, theproximal end114 of thefirst needle108 couples directly to theproximal end118 of thesecond needle110. In other embodiments, theproximal end114 of thefirst needle108 couples, via one or more sterile, intermediary, lumen-containing devices, to theproximal end118 of thesecond needle110. InFIG. 1, a flexiblesterile tubing120 is shown coupling theproximal end114 of thefirst needle108 to theproximal end118 of thesecond needle110. Thesterile tubing120 can be manufactured using any flexible, sterilizable, biocompatible material suitable for containing bodily fluids. Exemplary materials may include plastic, silicone rubber, and the like.
• Each of the one or morepre-sample reservoirs104 is sterile and includes aseptum122 covering amouth124 of each of thepre-sample reservoirs104. Eachseptum122 seals themouth124 and maintains an internal vacuum inside thepre-sample reservoir104. In at least some embodiments, theseptum122 is held in place by acrimp ring126. Likewise, each of the one ormore sample vessels106 is sterile and includes an internal vacuum maintained by aseptum128 covering amouth130 of each of the one ormore sample vessels106. In at least some embodiments, theseptum128 is held in place by acrimp ring132. The one or morepre-sample reservoirs104 and the one ormore sample vessels106 can be manufactured using any sterilizable, biocompatible material suitable for containing bodily fluids and culture media, or any other testing additives. Exemplary materials may include glass, plastic, and the like. In at least one embodiment, thefirst needle108, thesecond needle110, thesterile tubing120, the one or morepre-sample reservoirs104, and one ormore sample vessels106 are all disposable.
• Each of the one ormore sample vessels106 contains aculture medium134 for growing selected microbes. A culture medium may contain different amounts of different components, depending on the type of microbes being detected. A culture medium may include, for example, a nutrient broth with a carbon source, a nitrogen source, salts, water, and an amino acid source. Additionally, sample vessels undergoing microbial testing may be incubated at a specific temperature to further facilitate growth of a tested microbe.
• Examples of the sample-procurement system are shown inFIGS. 1-7, and also discussed in reference toFIGS. 1-7, in terms of procuring blood samples from a patient vein. Procuring blood from a patient vein is meant to serve as one of many possible types of bodily fluids parenterally withdrawn from one of many possible body locations.FIG. 2 is a schematic cross-sectional view of thefirst needle108 inserted into a lumen of avein202 of a patient. Thedistal end112 of thefirst needle108 is shown extending through multiple layers ofskin204 and a layer ofsubcutaneous fat206. Thefirst needle108 includes alumen208 extending along the length of thefirst needle108. When thedistal end112 of thefirst needle108 is inserted into a fluid-containing portion of a body, such as the lumen of thevein202, fluid within the fluid-containing portion of the body may be withdrawn from the fluid-containing portion of the body by passing the fluid through thelumen208 of thefirst needle108.
• In at least some embodiments, prior to penetration with thefirst needle108 patient skin is cleansed with one or more disinfectants to reduce the number of microbes on an outer surface of the patient skin. For example, patient skin can be cleansed with a gauze pad soaked with a disinfectant. Many different types of disinfectants may be used to cleanse patient skin. In one embodiment, patient skin is cleansed with a disinfectant that includes a 70% isopropyl alcohol solution, with 2% Chlorhexidine Gluconate, manufactured by MediFlex, Inc.
• Once thefirst needle108 is inserted into a desired fluid-containing body location, thesecond needle110 is inserted into thepre-sample reservoir104 and blood is withdrawn into the one or morepre-sample reservoirs104.FIG. 3A is a schematic view of one embodiment of the bodily-fluid withdrawing device102 being used to procure blood from thevein202 of a patient and depositing the blood in the one or morepre-sample reservoirs104. InFIG. 3A, thefirst needle108 is shown extending through apatient limb302 and into thevein202. Thesecond needle110 is in fluid communication with thefirst needle108, either directly, or via one or more intermediary lumen-containing devices, such as thesterile tubing120. Thesecond needle112 is inserted through theseptum122 and into the one or morepre-sample reservoirs104, which contains an internal vacuum. In at least some embodiments, the insertion of thesecond needle110 into the vacuum-sealedpre-sample reservoir106 creates a difference in pressure between the lumen of thefirst needle108 and the lumen of thesecond needle110. The pressure change causes the blood from thevein202 to be transferred into thepre-sample reservoir104 until the pressures equalize. Once the pressures equalize between the lumen of thefirst needle108 and the lumen of thesecond needle110, the blood tends to stop flowing from thevein202 to thepre-sample reservoir104. When the blood stops flowing into thepre-sample reservoir104, the second needle can be removed and inserted into another pre-sample reservoir or a sample reservoir.
• Accordingly, the initial portion of blood withdrawn from the patient is drawn into thepre-sample reservoir104 and is not used for cultured microbial testing. In a preferred embodiment, the amount of blood withdrawn into thepre-sample reservoir104 is at least equal to the combined volumes of the lumen of thefirst needle108, the lumen of thesecond needle110, and the lumens of any intermediary lumen-containing devices, such as thesterile tubing120. Dermally-residing microbes which may have been dislodged into the lumen of thefirst needle108 during the insertion of thefirst needle108 into thevein202 may be washed into thepre-sample reservoir104, thereby reducing the microbial contamination in the blood that is subsequently used as one or more samples for cultured microbial tests.
• The amount of blood transferred to thepre-sample reservoir104 may be regulated by the size of thepre-sample reservoir104. For example, a relatively large pre-sample reservoir may need to draw more blood to equalize pressure than a relatively small pre-sample reservoir. In at least some embodiments, the one or morepre-sample reservoirs104 are configured and arranged to hold approximately 1 ml to 5 ml. Thepre-sample reservoirs104 may also include one or more additives. For example, in at least some embodiments, thepre-sample reservoirs104 are BD Vacutainers™ with buffered citrate, manufactured by Becton Dickenson.
• In at least some embodiments, blood collected in one or more pre-sample reservoirs is discarded. In other embodiments, blood collected in one or more pre-sample reservoirs is used for conducting one or more non-culture tests, such as one or more biochemical tests, blood counts, immunodiagnostic tests, cancer-cell detection tests, and the like. In at least some embodiments, one or more pre-sample reservoirs may also include culture media for facilitating growth of one or more types of microbes.
• Once blood has been deposited in one or more pre-sample reservoirs, thesecond needle112 may be inserted into a sample vessel.FIG. 3B is a schematic view of one embodiment of the bodily-fluid withdrawing device102 being used to procure blood from thevein202 of a patient and depositing the blood in thesample vessel106. In at least some embodiments, the one ormore sample vessels106 are each vacuum-sealed. In a manner similar to the one or morepre-sample reservoirs104, the insertion of thesecond needle110 into the vacuum-sealedsample vessel106 tends to cause blood from thevein202 to be transferred into thesample vessel106 until the pressures equalize.
• In at least some embodiments, the amount of blood collected is determined based on the size of the sample vessel or the amount of blood needed to grow the microbes, if present, in the culture medium. In at least some embodiments, the one ormore sample vessels106 are configured and arranged to receive approximately 2 ml to 10 ml of bodily fluids in a sterile solid or liquid culture medium. In at least some embodiments, the one ormore sample vessels106 include the BacT/ALERT® SN and BacT/ALERT® FA, manufactured by BIOMERIEUX, INC.
• As discussed above, in at least some embodiments a sample-procurement system includes one or more pre-sample reservoirs and one or more sample vessels.FIG. 4A illustrates one embodiment of a sample-procurement system400 having a singlepre-sample reservoir402 and a plurality ofsample vessels404. The culture medium contained in each of the plurality ofsample vessels402 can be the same or can be different. For example, inFIG. 4A afirst sample vessel406 includes a sterilefluid culture broth408 for facilitating the growth of aerobic microbes, asecond sample vessel410 includes a sterilefluid culture broth412 for facilitating the growth of anaerobic microbes, and a third sample vessel414 includes asterile slant culture416 for facilitating the growth of fungi, or other microbes.
• In at least some embodiments, a sample-procurement system can include one or more accessory devices.FIG. 4B illustrates the sample-procurement system400 having asplash guard418 positioned over thesecond needle104. Thesplash guard418 can be used to reduce the risk of undesirable blood splatter when thesecond needle104 is transferred between thepre-sample reservoir402 and each of thesample vessels404.
• In at least some embodiments, a sample-procurement system includes a bodily-fluid withdrawing device with one or more intermediary lumen-containing devices, such as a diversion mechanism for diverting bodily fluid from the first needle to either one or more pre-sample reservoirs or to the second needle.FIG. 5 illustrates an alternate embodiment of a sample-procurement system500. The sample-procurement system500 includes a bodily-fluid withdrawing device502, one or morepre-sample reservoirs504, and one ormore sample vessels506. The bodily-fluid withdrawing device502 includes afirst needle508, a second needle510, adiversion mechanism512, a flexible,sterile input tubing514, one or more firststerile output tubing516, and a secondsterile output tubing518.
• InFIG. 5, thediversion mechanism512 is shown as a dashed rectangle. Thediversion mechanism512 is discussed below in more detail, with reference toFIGS. 6A-7B. In at least some embodiments, thefirst needle508 is coupled to thediversion mechanism512 via the flexible,sterile input tubing514. In at least some embodiments, the one or morepre-sample reservoirs504 are coupled to thediversion mechanism512 via the one or more firststerile output tubing516. In at least some embodiments, the second needle510 is coupled to thediversion mechanism512 via the secondsterile output tubing518. In at least some embodiments, at least onepre-sample reservoir504 is permanently attached to the bodily-fluid withdrawing device502. In at least some embodiments, at least onepre-sample reservoir504 is removably attached to the bodily-fluid withdrawing device502. In at least some embodiments, one or more of thetubing514,516, and518 are omitted and one or more of thefirst needle508, thepre-sample reservoir504, and the second needle510, respectively, couple directly to thediversion mechanism512.
• Thefirst needle508 can be inserted into a patient to procure a blood sample. InFIG. 5, thefirst needle508 is shown inserted into avein520. The second needle510 is shown inserted into the one ormore sample vessels506 that have been vacuum-sealed. The vacuum in each of the one ormore sample vessels506 causes blood to pass from thevein520 to thediversion mechanism512. Thediversion mechanism512 can be adjusted to divert the flow of blood to either the one or morepre-sample reservoirs504 or to the second needle510 inserted into one of the one ormore sample vessels506. For example, in at least some embodiments, thediversion mechanism512 can be initially adjusted to divert blood to the one or morepre-sample reservoirs504 until the one or morepre-sample reservoirs504 are filled, or a desired amount of blood has been withdrawn, at which point thediversion mechanism512 can be adjusted to divert the flow of blood to the one ormore sample vessels506. In at least some embodiments, the volume of blood withdrawn into the one or morepre-sample reservoirs504 is at least equal to the collective volumes of thefirst needle508, the flexible,sterile input tubing516, thediversion mechanism512, and the firststerile output tubing516.
• Many different types of diversion mechanisms can be used to divert the flow of bodily fluids from a patient.FIG. 6A illustrates one embodiment of thediversion mechanism512 that includes aswitchable valve602 that pivots about apivot point604 positioned at the junction of the firststerile output tubing516 and the secondsterile output tubing518. Theswitchable valve602 can be placed in at least two positions: a first position (seeFIG. 6A) and a second position (seeFIG. 6B). When theswitchable valve602 is in a first position, as shown inFIG. 6A, theswitchable valve602 is positioned on thepivot point604 so that theswitchable valve602 creates a seal disallowing the flow of blood input from the flexible,sterile input tubing514 into the secondsterile output tubing518. Consequently, the blood flows into the pre-sample reservoir (not shown) via the firststerile output tubing516.
• FIG. 6B illustrates one embodiment of theswitchable valve602 in a second position. When theswitchable valve602 is in a second position, theswitchable valve602 is positioned on thepivot point604 so that theswitchable valve602 creates a seal disallowing the flow of blood input from the flexible,sterile input tubing514 into the pre-sample reservoir (not shown) via the firststerile output tubing516. Consequently, the blood flows into the one or more sample vessels (not shown) via the secondsterile output tubing518. In at least some embodiments, thediversion mechanism512 includes more than two positions. In which case, each position may correspond to blood-flow diversion to a unique output tubing. In some embodiments, a plurality of pre-sample reservoirs may be used. In which case, each pre-sample reservoir may correspond to a unique diversion-mechanism position. Thus, in at least some embodiments, one position corresponds to diverting blood flow to the second needle and the other positions each correspond to a unique pre-sample reservoir.
• In at least some embodiments, the switchable valve can be manually switched between two or more positions by coupling an external switch to the switchable valve that can be operated either manually or electronically. In at least some embodiments, the external switch is external to each of the lumens of the bodily-fluid withdrawing device. In at least some embodiments, the switchable valve can be either manually or automatically switched between two or more of the positions by using sensors to sense when to switch a switchable valve, or timers to time when to switch a switchable valve.
• FIG. 7A illustrates another embodiment of thediversion mechanism512 that includes an input flow-control block702 and a slidably-mounted output flow-control block704 that slides along a shared edge with the input flow-control block702. The input flow-control block702 and the output flow-control block704 can be slid back and forth between a first position (seeFIG. 7A) and a second position (seeFIG. 7B). The input flow-control block702 is configured and arranged to couple with the flexible,sterile input tubing514. The input flow-control block702 includes alumen706 extending through the input flow-control block702 from the flexible,sterile input tubing514 to the shared edge with the output flow-control block704.
• The output flow-control block704 is configured and arranged to couple with the firststerile output tubing516 and the secondsterile output tubing518. The output flow-control block704 includes afirst lumen708 extending through the output flow-control block704 from the shared edge with the input flow-control block702 to the firststerile output tubing516, and asecond lumen710 also extending through the output flow-control block704 from the shared edge with the input flow-control block702 to the secondsterile output tubing518. When the input flow-control block702 and the output flow-control block704 are in a first position relative to one another, thelumen706 on the input flow-control block702 aligns with thefirst lumen708 on the output flow-control block704. Accordingly, the flow of blood input from the flexible,sterile input tubing514 passes through thelumen706 of the input flow-control block702 and through thefirst lumen708 of the output flow-control block704 and into the pre-sample reservoir (not shown) via the firststerile output tubing516.
• In at least some embodiments, once a desired amount of blood is diverted to the one or more pre-sample reservoirs, the flow-control blocks can be slid to a second position to divert blood flow to the second needle, which may be inserted into one of the one or more sample vessels.FIG. 7B illustrates one embodiment of the input flow-control block702 and the output flow-control block704 in a second position. When the input flow-control block702 and the output flow-control block704 are in a second position relative to one another, thelumen706 on the input flow-control block702 aligns with thesecond lumen710 on the output flow-control block704. Accordingly, the flow of blood input from the flexible,sterile input tubing514 passes through thelumen706 of the input flow-control block702 and through thesecond lumen710 of the output flow-control block704 and into the one or more sample vessels (not shown) via the secondsterile output tubing518. In at least some embodiments, the output flow-control block704 includes additional lumens that correspond to different positions which, in turn, may correspond to blood diversion to other pre-sample reservoirs, either directly, or via one or more intermediary output tubing.
• FIG. 8 illustrates a flow diagram showing one embodiment of exemplary steps used for procuring samples. Instep802, a first needle is inserted into a desired bodily-fluid-containing portion of a patient. Instep804, a second needle is inserted into a pre-sample reservoir. Instep806, a predetermined amount of bodily fluid is drained from the patient into the pre-sample reservoir. Instep808, the second needle is removed from the pre-sample reservoir. When, instep810, there is another pre-sample reservoir to drain bodily fluid into, control is passed back up tostep804. Otherwise, control passes to step812, where the second needle is inserted into a sample vessel. Instep814, a predetermined amount of bodily fluid is drained from the patient into the sample vessel. Instep816, the second needle is removed from the sample vessel. When, instep818, there is another sample vessel to drain bodily fluid into, control is passed back up tostep812. Otherwise, instep820 the first needle is removed from the patient and the flow ends.
• FIG. 9 illustrates a flow diagram showing a second embodiment of exemplary steps used for procuring samples. Instep902, a first needle is inserted into a desired bodily-fluid containing portion of a patient. Instep904, a second needle is inserted into a pre-sample reservoir. Instep906, a diversion mechanism is adjusted to direct the flow of bodily fluids to a desired pre-sample reservoir. Instep908, a predetermined amount of bodily fluid is drained from the patient into the pre-sample reservoir. When, instep910, there is another pre-sample reservoir to drain bodily fluid into, control is passed back up tostep906. Otherwise, control passes to step912, where the diversion mechanism is adjusted to divert bodily fluids to a sample vessel. Instep914, a predetermined amount of bodily fluid is drained from the patient into the sample vessel. Instep916, the second needle is removed from the sample vessel. When, instep918, there is another sample vessel to drain bodily fluid into, control is passed to step920, where the second needle is inserted into another sample vessel, and then control is passed back tostep914. Otherwise, instep922 the first needle is removed from the patient and the flow ends.
• Other alternate embodiments of the methods and systems described above include using a sterile syringe with at least two reservoirs. For example, in at least some embodiments, a sterile syringe with a lumen-containing needle and a removable first reservoir can be used for drawing and collecting pre-sample bodily-fluids from a patient. In at least some embodiments, the volume of collected pre-sample bodily-fluids is equal to, or greater than, the volume of the lumen of the needle. Once the desired amount of pre-sample bodily-fluids are collected, the first reservoir can be removed and a second reservoir can then be attached to the needle, already in place in the vein. In at least some embodiments, sample bodily-fluids can be drawn and collected in the second reservoir and subsequently be transferred to one or more sample vessels to undergo microbial testing.
• A study has been performed in which blood was drawn from patients either with or without separating initially-drawn blood into one or more pre-sample reservoirs. The data from the study has been provided below in Table 1.

• 	TABLE 1
  	No. of false	No. of correct
  	positives	negatives

  	Using pre-sample	77	1911	1988
  	reservoir
  	Without using pre-	48	580	628
  	sample reservoir
  		125	2491	2616

• In the data shown in Table 1, blood was drawn for microbial testing from patients at a single hospital by a group of licensed phlebotomists. Of the patients from which blood was drawn, 125 patients tested positive for the presence of dermal contaminating microbes (false positives). Of the 2616 patients tested for the presence of microbes, 1988 had an initial volume of drawn blood sequestered into a pre-sample reservoir that was not used for the microbial testing, while 628 patients did not. Of the patients from which a pre-sample reservoir was used, 77 of the 1988 test results were later determined to be false positive results, while 48 of the 628 test results from the patients for which initial blood volumes were used for microbial testing were later determined to be false positive results. The data suggests that fewer false positive test results occur when initial volumes of drawn blood are not used for microbial testing.
• A Pearson's Chi-Square Test was performed on the data from Table 1 and is provided below as Formula (1)
• $\begin{array}{cc}\frac{\begin{array}{c}\left[\left(77\times 580\right)-\left(48\times 1911\right)\right]2\times \\ \left(77+48+1911+580\right)\end{array}}{\left(77+1911\right)\text{'}\left(48+580\right)\times \left(1911+580\right)\times \left(77+48\right)}=\mathrm{14.91`}& \mathrm{Formula}\left(1\right)\end{array}$
• For the data shown in Table 1, there are two possible results: a correct (true) negative, and a false positive. The number of degrees of freedom is equal to the number of possible results minus one. A listing of various Chi-square probability values for 1 degree of freedom are provided in Table 2

• TABLE 2
  Probability

  	0.50	0.20	0.15	0.10	0.05	0.02	0.01	0.001

  1 degree of	0.46	1.64	2.07	2.71	3.84	5.41	6.63	10.83
  freedom

• As shown in Formula 1, the Chi-square value of the data shown in Table 1 is 14.91, which is higher than the probability of the result occurring by chance alone is less than one time out of a thousand. Thus, the data suggests that fewer false positive test results for the presence of microbes in blood are obtained over conventional methods when initially-drawn volumes of blood are not used in microbial testing.
• The above specification, examples and data provide a description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention also resides in the claims hereinafter appended.

Claims (31)

1.-20. (canceled)

21. A system for obtaining bodily-fluid samples from a patient, comprising:

a first needle having a lumen configured for insertion into the patient;

a second needle having a lumen configured to be fluidically coupled to the first needle;

an intermediary lumen-containing device configured to fluidically couple the lumen of the first needle to the lumen of the second needle; and

a pre-sample reservoir configured to be fluidically coupled to the lumen of the second needle, the pre-sample reservoir sized and configured to receive a first volume of bodily-fluid from the patient, the first volume of bodily-fluid being (a) greater than the combined volume of the lumen of the first needle, the intermediary lumen-containing device, and the lumen of the second needle, and (b) less than 5 ml,

whereby transferring the first volume of bodily-fluid to the pre-sample reservoir sequesters microbes present in the first volume of bodily-fluid thereby reducing contamination of any subsequent volumes of bodily-fluid withdrawn from the patient.

22. The system ofclaim 21, wherein sequestering the first volume of bodily-fluid in the pre-sample reservoir reduces false results in culture tests of a subsequent second volume of bodily-fluid by at least about 50%.

23. The system ofclaim 21, further comprising:

a guard configured to be disposed over the second needle.

24. The system ofclaim 21, further comprising:

a disinfectant for cleansing the patient's skin prior to insertion of the first needle.

25. The system ofclaim 24, wherein the disinfectant includes an isopropyl alcohol solution.

26. The system ofclaim 24, wherein the disinfectant includes chlorhexidine gluconate.

27. The system ofclaim 21, wherein the pre-sample reservoir is configured to receive 0.5 ml to 5 ml of bodily-fluid.

28. The system ofclaim 21, wherein the pre-sample reservoir is configured to receive 1 ml to 5 ml of bodily-fluid.

29. The system ofclaim 21, whereby dermally residing microbes dislodged while inserting the first needle into the patient are transferred to and sequestered in the pre-sample reservoir.

30. The system ofclaim 21, whereby a tissue fragment dislodged while inserting the first needle into the patient is transferred to and sequestered in the pre-sample reservoir.

31. A system for obtaining bodily-fluid samples from a patient, comprising:

a first needle configured for insertion into the patient;

a second needle configured to be fluidically coupled to the first needle;

a flexible tube configured to fluidically couple the first needle to the second needle; and

a vacuum-sealed pre-sample reservoir configured to be fluidically coupled to the second needle after the first needle has been inserted into the patient, the vacuum-sealed pre-sample reservoir having a volume in a range of 1 ml to 5 ml,

whereby transferring a first volume of bodily-fluid to the vacuum-sealed pre-sample reservoir sequesters dermally residing microbes dislodged while inserting the first needle into the patient, thereby reducing contamination of any subsequent volumes of bodily-fluid withdrawn from the patient.

32. The system ofclaim 31, wherein the vacuum-sealed pre-sample reservoir is a single Vacutainer.

33. The system ofclaim 31, wherein the vacuum-sealed pre-sample reservoir is a first vacuum-sealed pre-sample reservoir, the system further comprising:

a second vacuum-sealed pre-sample reservoir.

34. The system ofclaim 31, wherein sequestering the first volume of bodily-fluid in the vacuum-sealed pre-sample reservoir reduces false results in culture tests of a subsequent second volume of bodily-fluid by at least about 50%.

35. The system ofclaim 31, further comprising:

a guard configured to be disposed over the second needle.

36. The system ofclaim 31, further comprising:

a disinfectant for cleansing the patient's skin prior to insertion of the first needle.

37. A system for obtaining blood samples from a patient, comprising:

a first needle configured for insertion into the patient a venipuncture site;

a second needle configured to be fluidically coupled to the first needle;

a flexible tube configured to fluidically couple the first needle to the second needle; and

a vacuum-sealed pre-sample reservoir configured to be fluidically coupled to the second needle after the first needle has been inserted into the patient, the vacuum-sealed pre-sample reservoir sized and configured to draw a first volume of blood from the patient through the first needle, the flexible tube, and the second needle to the vacuum-sealed pre-sample reservoir until a pressure in the vacuum-sealed pre-sample reservoir is substantially equal to a vascular pressure of the patient at the venipuncture site, the first volume of blood in a range of 1 ml to 5 ml,

whereby transferring the first volume of blood to the vacuum-sealed pre-sample reservoir sequesters microbes present in the first volume of blood thereby reducing contamination of any subsequent volumes of blood withdrawn from the patient.

38. The system ofclaim 37, further comprising:

a sample vessel including a culture medium.

39. The system ofclaim 37, further comprising:

a first sample vessel including a first culture medium; and

a second sample vessel including a second culture medium.

40. The system ofclaim 39, wherein the second culture medium is different than the first culture medium.

41. The system ofclaim 37, further comprising:

a first sample vessel including an aerobic culture medium; and

a second sample vessel including an anaerobic culture medium.

42. The system ofclaim 37, whereby dermally residing microbes dislodged while inserting the first needle into the patient are transferred to and sequestered in the vacuum-sealed pre-sample reservoir.

43. The system ofclaim 37, whereby a tissue fragment dislodged while inserting the first needle into the patient is transferred to and sequestered in the pre-sample reservoir.

44. The system ofclaim 37, wherein sequestering the first volume of bodily-fluid in the pre-sample reservoir reduces false results in culture tests of a subsequent second volume of bodily-fluid by at least about 50%.

45. The system ofclaim 37, further comprising:

a guard configured to be disposed over the second needle.

46. The system ofclaim 37, further comprising:

a disinfectant for cleansing the patient's skin prior to insertion of the first needle.

47. A system for obtaining bodily-fluid samples from a patient, the system consisting essentially of:

a first needle configured for insertion into the patient;

a second needle configured to be fluidically coupled to the first needle;

a flexible tube configured to fluidically couple the first needle to the second needle;

a vacuum-sealed pre-sample reservoir configured to be fluidically coupled to the second needle after the first needle has been inserted into the patient, the vacuum-sealed pre-sample reservoir having a volume in a range of 1 ml to 5 ml,

whereby transferring a first volume of bodily-fluid to the vacuum-sealed pre-sample reservoir sequesters microbes present in the first volume of bodily-fluid thereby reducing contamination of any subsequent volumes of bodily-fluid withdrawn from the patient.

48. The system ofclaim 47, wherein sequestering the first volume of bodily-fluid in the pre-sample reservoir reduces false results in culture tests of a subsequent second volume of bodily-fluid by at least about 50%.

49. The system ofclaim 47, whereby dermally residing microbes dislodged while inserting the first needle into the patient are transferred to and sequestered in the pre-sample reservoir.

50. The system ofclaim 47, whereby a tissue fragment dislodged while inserting the first needle into the patient is transferred to and sequestered in the pre-sample reservoir.

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