U.S. patent application number 11/318079 was filed with the patent office on 2006-07-13 for closed system catheterization assembly and related methods.
This patent application is currently assigned to Aragon Medical Corporation. Invention is credited to Mark W. Godfrey, Bobby E. Rogers.
Application Number | 20060155258 11/318079 |
Document ID | / |
Family ID | 32824254 |
Filed Date | 2006-07-13 |
United States Patent
Application |
20060155258 |
Kind Code |
A1 |
Rogers; Bobby E. ; et
al. |
July 13, 2006 |
Closed system catheterization assembly and related methods
Abstract
The invention concerns catheterization assemblies designed to
reduce the risk of infection, transmission of bloodborne pathogens,
loss of blood, and development of embolisms in a patient.
Embodiments of the invention are directed to a catheterization
assembly having a catheter hub with multiple access ports. In some
embodiments, the catheter hub is permanently attached to a catheter
and a valve. The catheter hub provides fluid communication between
the valve and the catheter. The catheter hub may also be provided
with a sealing member that provides access to a fluid passageway of
the catheter hub but which prevents leakage of fluids from the
catheter hub. In other embodiments, the catheter hub includes a
passageway and an air vent for allowing air to pass out of the
catheterization assembly.
Inventors: |
Rogers; Bobby E.; (San
Diego, CA) ; Godfrey; Mark W.; (Ramona, CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Assignee: |
Aragon Medical Corporation
San Diego
CA
|
Family ID: |
32824254 |
Appl. No.: |
11/318079 |
Filed: |
December 22, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10361506 |
Feb 7, 2003 |
6979323 |
|
|
11318079 |
Dec 22, 2005 |
|
|
|
Current U.S.
Class: |
604/508 ;
604/264; 604/284 |
Current CPC
Class: |
A61M 39/06 20130101;
A61M 25/0097 20130101; A61M 39/26 20130101 |
Class at
Publication: |
604/508 ;
604/284; 604/264 |
International
Class: |
A61M 31/00 20060101
A61M031/00 |
Claims
1. A method of catheterization comprising: accessing a patient's
peripheral vein with a catheterization device comprising: a
catheter tube non-removably attached to a catheter hub; a valve
non-removably attached to the catheter hub; and a needle for
puncturing the vein, and wherein a lumen of the needle fits inside
the catheter tube; puncturing the vein with the needle; inserting
the catheter tube into the vein; and removing the needle from the
catheterization device.
2. The method of claim 1, wherein the catheter tube is a peripheral
catheter.
3. The method of claim 2, wherein the peripheral catheter is less
than about 6 inches long.
4. The method of claim 3, wherein the peripheral catheter is less
than about 4 inches long.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to vascular access devices
such as catheter assemblies. The invention is particularly directed
to a catheterization assembly designed to reduce the risk of
infection, transmission of bloodborne pathogens, loss of blood, and
development of embolisms in a patient. The catheterization assembly
incorporates a catheter hub that has multiple access ports for
allowing air to exit the catheterization assembly, providing fluid
communication between a valve and a catheter, and enabling
insertion and removal of a catheter introducer without leakage of
body fluids from the catheterization assembly.
[0003] 2. Description of the Related Art
[0004] In current medical practice, it is often necessary to have
access to the venous system of a patient. For example, it is a
common procedure to obtain diagnostic information about the heart
or its vessels by inserting a tube (a "catheter") into a vein of
the patient and withdrawing blood. Oftentimes, catheterization is
necessary to deliver fluids such as medications into the patient's
venous system. Additionally, it may be necessary to aspirate fluids
from the catheter site to evaluate blood profiles, perform
diagnostic assays, etc.
[0005] Typically catheterization is conducted by inserting a
needle, or other introducer, directly into a patient's vein and
pushing or threading a catheter through the entry site created by
the needle. Conventional catheterization practice has been to
introduce the catheter into the patient's vein and then to attach a
secondary component, such as an injection port with a sealed
septum, to the catheter to prevent blood leakage, minimize catheter
clotting, and to facilitate the introduction of medications or
aspirate fluids. In this case the introduction or aspiration of
fluids is accomplished by utilizing a needle to penetrate the
septum thereby accessing the patient's vasculature via the
catheter. The needle is generally inserted into a sealed entry
port.
[0006] Since the early 1990's, infection by bloodborne pathogens
has become a serious concern to health care workers and patients
alike. HIV/AIDS and various forms of hepatitis have caused a
dramatic shift in the way medical devices are constructed. The
elimination of needle sticks and blood contact have been the
primary design changes. However, many devices currently marketed as
"safety" devices fall short of the goal of preventing the
transmission of bloodborne pathogens.
[0007] Any device connected to the patient's bloodstream should not
have an exposed fluid reservoir due to the potential for bacterial
infection from contact with a tainted object. If the fluid
reservoir or cavity is not cleaned, then there is a potential for
developing bacteria in the fluid reservoir. The bacteria could be
introduced into a patient's bloodstream when the device is
subsequently used to administer new medications to or aspirate
fluids from the patient. Additionally, there is a risk of blood
coagulating in the catheter and possibly in the injection
apparatus; hence, these components must be frequently replaced
thereby creating possible medical complications as well as
additional discomfort, pain, and cost to the patient.
[0008] Turning in particular to the case of catheters, certain
catheters such as Peripherally Inserted Central catheters
("PICCs"), Midline ("Mid") catheters, and Peripheral catheters can
remain in a patient for hours or in some cases as long as 180 days.
During the course of treatment with a catheter, a patient's venous
system may be accessed a number of times to either remove or
introduce fluids.
[0009] The traditional PICC, Mid, or peripheral catheter is
constructed of a length of tubing terminating at the proximal end
with a female luer hub (a "catheter hub"). The primary difference
between these three catheters is the length of the tubing. The
rationale for different lengths is based on the type and duration
of the therapy a patient is to receive.
[0010] The insertion of these catheters into a patient's venous
system can differ procedurally. The peripheral catheter, being the
shortest of the three types and measuring about 3.5'' in length, is
often inserted into a patient's vein through the use of a needle
disposed within the catheter tube. These types of catheters are
frequently referred to as "over-the-needle catheters." The
peripheral catheter is percutaneously inserted into a peripheral
vein and terminates in the same peripheral vein. After insertion,
the needle is removed, leaving the catheter in the vein. Often,
blood will flow out of the back of the luer hub and expose the
health care worker to blood contact. Usually, a second component
commonly referred to as a "J-loop" is attached to the catheter
hub.
[0011] A J-loop is a tube approximately 6'' in length and is often
configured with an injection cap, luer fitting, or needle free
valve at its proximal end. Typically, the J-loop is also configured
with a male luer fitting at its distal end for attachment to other
devices. The J-loop primarily functions to allow handling of
injection ports or fluid flow regulating devices away from the
point of insertion of the catheter into the patient. Without the
use of a J-loop, manipulation of an injection cap, for example,
connected directly to the catheter hub would likely result in the
inadvertent dislodging of the catheter from the patient. When the
J-loop is not supplied with some terminal connector the health care
worker must supply one in order to prevent leakage of bodily fluids
from the J-loop, or to provide an access port to the catheter via
the J-loop.
[0012] The PICC and Mid are inserted in a similar fashion.
Typically, an introducer is placed into the vein first. The
introducer is a thin splittable tube whose internal diameter (ID)
is closely matched to the outside diameter (OD) of the internally
disposed needle in much the same way as described with reference to
the peripheral catheter. Once the introducer has been placed in the
vein, the needle is removed and again, blood can be seen to come
out of the proximal end of the introducer. The introducer will
remain in place and acts as a conduit for threading the PICC or Mid
catheter into the patient's vein. Once the PICC or Mid catheter is
in the vein, the introducer is removed, and blood can often escape
from the hub of the catheter.
[0013] Thus, to date, there is an absence of safety devices on the
market which reduce or prevent the risk of exposure to bloodborne
pathogens to health care workers during and after catheter
insertion.
[0014] It has also been recognized that known catheterization
devices contribute to the incidence of transmission of nosocomial
infections to a patient undergoing catheterization. Since 1970, the
Center for Disease Control (CDC)'s National Nosocomial Infection
Surveillance System (NNIS) has been collecting data on the
incidence and etiologies of hospital acquired infections. The
majority of hospital-acquired bloodstream infections are associated
with the use of a catheter, particularly central venous
catheters.
[0015] Today, catheter maintenance requires many manipulations of
the catheter. For example, every three days, injection caps,
valves, and tubing must be replaced. In so doing, the health care
worker can inadvertently expose the patient to nosocomial
infections caused by bacteria, viruses, and/or fungi. Each and
every manipulation that opens the catheter's closed system exposing
it to airborne bacteria and touch contamination is a potential
source of danger to the patient. Types of organisms that most
commonly cause hospital-acquired bloodstream infections include,
Staphylocooccus aureus, Candida spp., Escherichia coli, Pseudomonas
aeruginosa, Acinetobacter calcoaceticus, and Klebsiella pneumoniae.
These microorganisms can infect the patient's bloodstream and, in
extreme cases, sepsis and death can result.
[0016] The known catheterization devices typically lack features to
reduce the risk to the patient of an air embolism. The insertion of
a central catheter exposes a patient to the possibility of
"sucking" air through the catheter into the patient's bloodstream.
This risk can result in death or serious injury to the patient.
[0017] Moreover, the known catheterization assemblies often
increase the cost of medical care. In today's market, as stated
earlier, PICCs can often be in a patient for periods of time up to
180 days. Valves are attached to these catheters to allow for the
introduction of drugs, diagnostic agents, etc. Because the valves
are detachable, the Center for Disease Control ("CDC") dictates
that these valves must be replaced every 72 hours. Valves typically
cost approximately $1.50/each (USD). Over a 180 day period, on
average, sixty valves must be replaced at a cost of nearly $90.00
(USD). Accordingly, there is a need for catheterization assemblies
having valves which prevent blood backflow and which are not
required to be replaced periodically to reduce health care
costs.
[0018] Consequently, there is a constant need in the relevant
technology for improved safety devices which prevent or reduce the
risk to the patient of transmission of bloodborne pathogens, loss
blood, infection, or air embolism in the course of insertion and
use of catheter devices. Additionally, affordable safety devices
would be a great benefit to both the patient and medical
community.
SUMMARY OF THE INVENTION
[0019] The catheterization assembly of the invention has several
aspects, no single one of which is solely responsible for its
desirable attributes. Without limiting the scope of this invention
as expressed by the claims which follow, its more prominent
features will now be discussed briefly.
[0020] To meet the current need for a catheterization assembly that
protects health care workers from bloodborne pathogens and needle
sticks, in one embodiment the invention provides a fully assembled,
safety bloodless catheterization assembly. The catheterization
assembly eliminates potential contact with bloodborne pathogens by
providing a closed catheterization assembly system. The
catheterization assembly also reduces points of connection thereby
reducing sources of contamination as well as sources of leaks from
separation or loose connections. The catheterization assembly
additionally simplifies catheterization by reducing the number of
components that a health care worker must attach to a
catheterization device in the field.
[0021] A feature of the invention is directed to catheter
assemblies having a valve integrally attached to a catheter hub.
The catheterization assemblies are designed to reduce the risk of
infection, transmission of bloodborne pathogens, loss of blood, and
development of embolisms in a patient. In some embodiments, a
catheterization assembly comprises a valve permanently attached to
the hub.
[0022] In some embodiments, the catheterization assembly comprises
a catheter hub that provides multiple access ports to a catheter
inserted in a patient's vein, is configured to allow air to exit
the catheter hub, and which provides fluid communication between
the catheter and a valve permanently attached to the catheter
hub.
[0023] One feature of the invention concerns catheterization
assembly having a catheter permanently attached to a catheter hub.
The hub comprising a first channel having first and second ends,
wherein the first channel is configured at the first end to provide
fluid communication with the catheter, and wherein the first
channel is configured at the second end for permanent attachment to
a sealing member. The catheter hub further comprises a second
channel having first and second ends, wherein the second channel is
configured at the first end to provide fluid communication with the
first channel. The catheterization assembly further comprises a
first tube having proximal and distal ends, wherein the distal end
of the tube is permanently attached to the second end of the second
channel. The catheterization assembly further comprises a valve
permanently attached to the proximal end of the first tube.
[0024] Another aspect of the invention is related to a
catheterization assembly comprising a catheter hub permanently
attached to a catheter and to a valve, wherein the valve is located
outside of the catheter hub.
[0025] One embodiment of the invention is directed to a catheter
hub. The catheter hub comprises a first passageway having proximal
and distal ends, wherein the first passageway is configured at the
distal end for non-removable attachment to a catheter, and
configured at the proximal end for nonremovable attachment to a
sealing member. The catheter hub further comprises a second
passageway having proximal and distal ends, wherein the second
passageway is configured at the proximal end for non-removable
attachment to a valve, and wherein the distal end of the second
passageway is configured to provide fluid communication with the
first passageway.
[0026] Yet another embodiment of the invention relates to a
catheter hub for use in catheterization. The hub comprises a first
channel providing a fluid passageway through the hub, wherein the
first channel is configured to provide fluid communication with a
catheter. The hub further comprises a second channel having a
proximal end configured to provide fluid communication with the
first channel and a distal end configured to provide fluid
communication with a valve. The hub further comprises a third
channel having a proximal end configured to provide fluid
communication with the first channel and a distal end configured to
provide fluid communication with an air vent.
[0027] Another feature of the invention is directed to a
catheterization system. The catheterization system comprises a
first tube having a distal end and a proximal end, wherein the
first tube defines a fluid passageway between the distal and
proximal ends. The catheterization system further comprises a hub
attached to the first tube. The hub comprises a first passageway
that is colinear with the passageway of the first tube, a second
passageway configured to provide fluid communication with the first
passageway, and a third passageway configured to provide fluid
communication with the first passageway. The catheterization system
further comprises a valve in fluid communication with the second
passageway and configured to regulate a fluid flow in the second
passageway. The catheterization system may further comprise an air
vent configured to allow passage of air from the third passageway
to the outside of the hub.
[0028] Yet another embodiment of the invention concerns a method of
manufacturing a catheterization assembly. The method comprises
permanently attaching a catheter tube to a catheter hub, and
permanently attaching the catheter hub to a valve.
[0029] Another feature of the invention concerns a method of
manufacturing a catheter assembly. The method comprises permanently
attaching a catheter hub to a valve, wherein the catheter hub
comprises a catheter tube.
[0030] Another aspect of the invention is directed to a
catheterization device. The catheterization device comprises means
for accessing a patient's vein, and means for supporting the means
for accessing, wherein the means for supporting is permanently
attached to the means for accessing. The catheterization device
further comprises means for regulating a fluid flow in the means
for accessing and the means for supporting, wherein the means for
regulating is permanently attached to the means for supporting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The above and other aspects, features, and advantages of the
invention will be better understood by referring to the following
detailed description, which should be read in conjunction with the
accompanying drawings, in which:
[0032] FIG. 1 is a diagram of a catheterization assembly according
to the invention as may be used in a clinical setting.
[0033] FIG. 2 is schematic illustration of one embodiment of a
catheterization assembly according to the invention.
[0034] FIG. 3 is a schematic illustration of an exemplary
catheterization assembly having an air vent in accordance with one
embodiment of the invention.
[0035] FIG. 4 is a schematic illustration of yet another embodiment
of the invention, showing a catheterization assembly having an air
vent.
DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS
[0036] Embodiments of the catheterization assemblies and related
methods of making and using will now be described with reference to
the accompanying figures, wherein like numerals refer to like
elements throughout. One embodiment of the invention is directed to
a catheterization assembly having a catheter hub that provides
multiple access ports to a catheter inserted in a patient's vein,
and which is configured to allow air to exit the catheter hub, and
which is in fluid communication with a valve attached to the
catheter hub. The catheterization assembly is designed to reduce
the risk of infection, transmission of bloodborne pathogens, loss
of blood, and development of embolisms in a patient.
[0037] The terminology used in the description presented herein is
not intended to be interpreted in any limited or restrictive manner
simply because it is being utilized in conjunction with a detailed
description of certain specific embodiments of the invention.
Furthermore, embodiments of the invention may include several novel
features, no single one of which is solely responsible for its
desirable attributes or which is essential to practicing the
invention.
[0038] FIG. 1 depicts a catheterization assembly I 00 in accordance
with the invention as may be used in a clinical setting. The
exemplary illustrative use of FIG. 1 is merely by way of a brief
introduction, and is not meant to be limiting; moreover, the
catheterization assembly 100 will be described in detail with
reference to FIGS. 2, 3, and 4 below. In one embodiment, the
catheterization assembly 100 comprises a catheter hub 10 having at
its proximal end a sealing member 50. The catheter hub 10 is also
attached at its distal end to a catheter 20. The catheter hub 10
may be configured to connect permanently to a tube 40, which tube
40 is itself permanently connected or attached to a valve 30.
Typically the valve 30 is configured for fluid communication with
an intravenous set comprising a tube 80, appropriate fittings (not
shown), and a fluid reservoir 90.
[0039] In using the catheterization assembly 100, a user inserts
the catheter 20 into a vein (not shown) of an arm 95 of patient.
The catheter 20 is usually secured to the arm 95 by a piece of tape
85 or other similar device. Once inserted into and secured to the
arm 95, the catheter 20 serves to deliver fluids to the patient.
For example, fluid from the reservoir 90 flows into the tube 80.
The valve 30 regulates flow from the tube 80 to the tube 40 and, of
course, to the catheter hub 10. The fluid passes from the catheter
hub 10 to the catheter 20 and into the arm 95 of the patient. It
should be apparent to the person of ordinary skill in the relevant
technology that the catheterization assembly 100 may be used
analogously to withdraw blood from the patient. The catheterization
assembly 100 is designed so that a user may conveniently fit the
patient with the catheterization assembly 100 without blood leaking
from the catheter hub 10 and without requiring additional effort in
securing other devices to the catheter hub 10.
[0040] FIG. 2 illustrates one embodiment of a catheterization
assembly 100 according to the invention. In this embodiment, a
catheterization device 100 comprises a catheter hub 10 attached to
a catheter 20. The catheter hub 10 is configured to provide fluid
communication between the catheter 20 and a valve 30. In some
embodiments, as shown in FIG. 2, a tube 40 provides fluid
communication between the catheter hub 10 and the valve 30. In this
embodiment, the catheterization device 100 includes a sealing
member 50 attached to the catheter hub 10.
[0041] The catheter hub 10 comprises a fluid passageway 12
configured so as to provide fluid communication between the
catheter hub 10 and a fluid passageway 24 (see FIGS. 3 and 4) of
the catheter 20. In one embodiment, the diameter of the fluid
passageway 12 is greater than the diameter of a fluid passageway 24
of the catheter 20. The catheter hub 10 also comprises a fluid
passageway 14 that is configured so as to provide fluid
communication between the fluid passageway 12 and the tube 40 or
the valve 30, depending on the specific embodiment. In one
embodiment, the sealing member 50 is positioned at the proximal end
of the fluid passageway 12 to prevent outflow of fluids from the
proximal end of the fluid passageway 12. As is discussed further
below, the proximal end of the fluid passageway 12, with its
sealing member 50, is configured to provide an access port into the
catheter hub 10.
[0042] The catheter hub 10 may be a rigid part molded from a
plastics such as polycarbonate, ABS, or Acrylic Nylons (e.g., Nylon
6, Nylon 6/6, Nylon 11, Nylon 12). The catheter hub 10 may also be
made of a bio-compatible metal such as stainless steel, for
example. The methods of manufacturing plastic or metallic catheter
hubs are well known in the relevant technology, and a person of
ordinary skill in the relevant technology will readily recognize
that such methods are applicable to making the catheter hub 10. The
fluid passageways 12 and 14 are preferably straight and properly
sized for delivering fluids to or aspirating blood from a patient
via the catheter 20. The fluid passageways 12 and 14 may be formed
by boring holes into a solid piece of plastic or metal, or by
plastic molding of the catheter hub 10.
[0043] The catheter 20 is preferably constructed from a
biocompatible thermoplastic material such as tubing commercially
available from, for example, ExtruMed, Inc. (Placentia, Calif.) or
Advanced Polymers (Salem, N.H.). The catheter tube 20 may be
co-extruded tubing, irradiated high strength balloon tubing,
polyolefin heat shrink tubing, single or multi striped tubing,
straight or tapered tubing. For example, one of ordinary skill in
the relevant technology will appreciate that the catheter 20 may be
constructed from any suitable flexible material such as PolyEther
Block Amide (PEBAX.RTM.) (available from Modified Polymer
Components, Inc. of Sunnyvale, Calif.), PolyOlefins (LDPE, LLDPE,
HDPE, PP), PolyVinyl Chloride (PVC), PolyVinylidene Fluoride
(PVDF), Styrene-Ethylene-Butylene-Styrene Block Copolymer
(C-Flex.RTM.) (Consolidated Polymer Technologies, Inc., Clearwater,
Fla.), and Thermoplastic PolyUrethanes (TPUs). In a preferred
embodiment, the catheter 20 is constructed from Thermoplastic
PolyUrethanes (TPUs).
[0044] The catheter 20 may have length "L" that varies in
accordance with the type and duration of the therapy a patient is
to receive. In one embodiment, the length of the catheter 20 is
preferably about 6'' long, more preferably less than about 4.5''
long, and most preferably less than about 3.75'' long. Of course,
the catheterization assembly 100 need not be limited to any one
length L. Suitable catheters 20 include, without limitation,
Peripherally Inserted Central catheters ("PICCs"), Midline ("Mid")
catheters, Peripheral diagnostic and therapeutic catheters.
Examples of diagnostic catheters include, without limitation, those
catheters used in angiography; advanced sensor catheters for
measuring blood oxygen, venous oxygen, and cardiac output; and
diagnostic imaging catheters. Examples of therapeutic catheters
include, without limitation, atherectomy, angioplasty, RF ablation,
etc.
[0045] The valve 30 is preferably integrally attached to the tube
40 or to the catheter hub 10. As used here, the phrases "integrally
attached" or "permanently attached" are defined to mean "welded,
bonded, adhered to, or press fit to in a fixed, non-removable
manner." That is, a permanent or integral attachment is designed so
that it is not meant to be, and cannot be, disassembled in ordinary
use. The tube 40 is preferably also permanently attached to the
catheter hub 10.
[0046] Since the valve 30 is permanently attached to the catheter
hub 10, and the fluid passageway 12 is sealed by the sealing member
50, the catheterization assembly 100 is a closed system. That is,
blood or any other biological fluid is prevented from seeping out
of the proximal end of catheter hub 10 by the valve 30, as well as
the sealing member 50, thereby minimizing the exposure of health
care workers to bloodborne pathogens from a patient. Unlike open
catheters which allow air to be sucked into the system and pose a
risk for developing an embolism, the catheterization assembly 100
includes a permanently attached valve 30 that prevents air from
being pulled into the catheter 20 and therefore reduces the
incidence of embolism development. Of course, as already stated, in
some embodiments the valve 30 may be permanently attached to the
catheter hub 10 via the tube 40, as shown in FIG. 2. Because the
valve 30 is not detachable, it is not governed by the CDC mandate
which dictates that detachable valves must be replaced every 72
hours. Thus, the valve 30 may remain attached to the catheter hub
10 for the duration of the treatment process.
[0047] It will be appreciated by one of skill in the relevant
technology that the valve 30 may be any needle-free valve assembly,
for example, having the foregoing characteristics and which is
suitable for integral attachment to the tube 40 or to the catheter
hub 10. In some embodiments it is advantageous to have a
needle-free valve fixedly attached to a catheterization assembly
100. Such a valve can be used repeatedly without the use of a
needle to introduce medications into, or aspirate fluids from, a
patient's blood.
[0048] In some embodiments, the valve 30 may be a needle-free,
positive displacement, luer-activated valve designed to prevent
blood from being drawn back into the catheterization assembly 100
at the conclusion of the delivery or aspiration of fluids to or
from a patient's venous system. Additionally, valve 30 avoids
potential clogging of the catheter hub 10 or catheter 20, while at
the same time avoiding potential contamination of the interior of
the valve 30 due to contaminants external to the patient that find
their way into the interior of the valve 30. The valve 30 is
preferably swabbable, thereby preventing the introduction of
bacteria into the patient's bloodstream upon subsequent use of the
catheterization assembly 100 for dispensing medication.
[0049] The materials used for manufacturing the valve 30 preferably
have the characteristics of acceptable medical grade plastic that
can be precision molded and adapted to maintain its dimensions
under normal hospital conditions. When a positive displacement
valve 30 is employed, the material of the valve 30 is preferably
resistant to alcohol and has a low coefficient of friction.
Examples of suitable materials include polycarbonate, PVC, nylon,
Delrin, and hydrel. In a preferred embodiment, the valve 30 is
constructed from polycarbonate because of its long shelf life,
ability to be sterilized, and use in a clear, translucent, or
colored form.
[0050] As will be apparent to a person of ordinary skill in the
relevant technology, a luer fitting (not shown) may be attached to
the valve 30. The luer fitting may be, for example, a female luer
fitting suitable for connection to T connectors, Y connectors, IV
sets or syringes. Advantageously, all of these "IV devices" may
have a male luer for mating with the luer fitting of the valve
30.
[0051] The tube 40 may be constructed of a molded plastic material.
The tube 40 is designed to provide fluid communication between the
catheter hub 10 and the valve 30. In some embodiments, the tube 40
may comprise a male fitting that engages a female fitting in the
catheter hub 10. However, these fittings must be designed such that
once the fitting of the tube 40 is coupled to the fitting of the
catheter hub 10 it is not possible to disassemble the connection
without utilizing a specialized tool or damaging the
catheterization assembly 100. In some embodiments, the tube 40 is
configured so as to provide a permanent fluid passageway between
the catheter hub 10 and the valve 30. In one embodiment of the
catheterization assembly 100, an injection cap (not shown) rather
than the valve 30 is permanently attached to the proximal end of
the tube 40. Injection caps are well known in the relevant
technology.
[0052] The sealing member 50 may be a self-sealing septum made from
an elastomeric material. The sealing member 50 is preferably
permanently attached to the catheter hub 10 at the proximal end of
the fluid passageway 12. The sealing member 50 is typically a
self-sealing, normally-closed valve that allows introduction of a
needle, or other cannula-type device, into the passageway 12. The
use and construction of a suitable septum that can perform the
functions of the sealing member 50 is well known in the relevant
technology, and hence, need not be further described.
[0053] As already mentioned, in a preferred embodiment, the
catheter 20 is permanently attached to the catheter hub 10. The
catheter 20 may be affixed to the catheter hub 10 by any of several
means including, for example, chemical bonding, welding, or by a
press fit. The fluid passageway 12 provides fluid communication
between the catheter 20 and intravenous therapy ("IV") devices
external to the catheter hub 10 that may be inserted into, or
brought into fluid communication with, the fluid passageway 12 via
the sealing member 50. The fluid passageway 12 is also configured
to provide fluid communication between the tube 40 and the catheter
20 by being in fluid communication with the fluid passageway
14.
[0054] Typically the catheter 20 is made of a soft bio-compatible
material that makes it difficult to insert the catheter 20 into a
patient because its soft or pliable construction causes the
catheter 20 to collapse or bend before entering the patient's
veins. In order to quickly and efficiently insert the catheter 20,
a flexible stylet, guidewire, or needle is used as a stiffening
member inside the catheter 20 during insertion. It is to be
understood that the catheterization assemblies described here may
be used with any introducer device. However, for convenience, the
discussion here will only refer to a needle as the introducer
device. Additionally, it will be recognized by the person of
ordinary skill in the art that the invention and related methods
described here are readily applicable to catheters of rigid
construction such as, for example, some well known peripheral
catheters.
[0055] The needle 4 and the catheterization assembly 100 are
preferably pre-assembled by a manufacturer before use in a clinical
setting. As assembled, the needle 45 passes through the sealing
member 50, fluid passageway 12, and exits the distal end 22 of the
catheter 20. The needle 45 is chosen such that the outer surface of
its lumen 47 fits close to the internal surface of the catheter 20,
thereby substantially preventing fluid flow from the fluid
passageway 12 into the fluid passageway 24 of the catheter 20. It
should be noted that FIG. 2 shows an exaggerated distance between
the lumen 47 and the catheter 20 only to make the drawing clear.
However, since the diameter of the fluid passageway 12 is greater
than that of the outer diameter of the lumen 47, there is a space
46 around the lumen 47 in the fluid passageway 12 that allows for
fluid flow.
[0056] Prior to inserting the needle 45 and catheter 20 into a
patient, a user may prime the catheterization assembly 100. To
accomplish this priming operation, the user attaches a syringe (not
shown) to the valve 30 in a conventional manner as is well known in
the relevant technology. The syringe is typically pre-filled with a
priming fluid such as a heparin or a saline solution. The user
introduces the priming fluid from the syringe through the valve 30,
the tube 40, and into the fluid passageway 14. From the fluid
passageway 14, the priming fluid flows into the fluid passageway 12
and fills the area around the lumen 47 of the needle 45. This
priming process aids in removing air from the fluid passageway 12
and the fluid passageway 14, and also aids in cleaning these fluid
passageways of blood clots, bacteria, and other contaminants.
[0057] After the user primes the catheterization assembly 100, the
user may proceed to insert the catheter 20 into a patient in the
typical fashion. That is, once the user finds a vein and pierces it
with the needle 45 (i.e., the user notices "flashback" in the hub
of the needle 45), the user pushes the catheterization assembly 100
toward the vein, thereby inserting the catheter 20 over the needle
45 into the opening created by the needle 45. The user then removes
the needle 45 from the catheterization assembly 100. The sealing
member 50 prevents blood from flowing out of the proximal end of
the catheter hub 10 by self-sealing itself as the user pulls the
needle 45 out from the fluid passageway 12 and through the sealing
member 50.
[0058] It should be apparent to the person of ordinary skill in the
relevant technology that with the catheterization assembly 100,
removal of the needle 45 from the catheterization assembly 100 does
not result in leakage of blood. Additionally, the user need not
provide further assemblies, such as a J-loop, fittings, or
valves.
[0059] In addition to preventing the transmission of blood
borne-infections, the invention contemplates methods of reducing
the development of air emboli attendant with the placement of a
catheterization assembly into the venous system of a patient. In
some cases, an open catheterization assembly can allow air to be
sucked into the patient, threatening the patient with an air
embolism. However, by utilizing a catheterization assembly having a
valve attached to a catheter hub to prevent blood backflow, the
incidence of air emboli is greatly diminished because the
catheterization assembly remains closed.
[0060] FIG. 3 illustrates a catheterization assembly 200 similar to
the catheterization assembly 100 described above. The
catheterization assembly 200 comprises a catheter hub 10 attached
to a catheter 20 and a valve 30. The catheter hub 10 may be in
fluid communication with the valve 30 via a tube 40 that is
attached to both the catheter hub 10 and the valve 30. The catheter
hub 10 comprises at least two fluid passageways, namely fluid
passageway 12 and fluid passageway 14. The catheterization assembly
200 also includes a sealing member 50 that may be attached to the
catheter hub 10 at the proximal end of the fluid passageway 12. The
catheter hub 10, catheter 20, valve 30, tube 40, sealing member 50,
and fluid passageways are similar in form and construction as those
already described with reference to catheterization assembly 100 of
FIG. 2.
[0061] The catheterization assembly 200, however, additionally
comprises a cannula 60 having an air vent 65. In some embodiments,
the cannula 60 is attached to the needle 45 so that the cannula 60
and the needle 45 may be inserted into or removed from the fluid
passageway 12 simultaneously. In other embodiments, the cannula 60
may be adapted so that a user removes the cannula 60 from the
sealing member 50 separately from removal of the needle 45.
[0062] The cannula 60 may be a tube made of a bio-medical material,
such as stainless steel. The cannula 60 allows flow of air from the
fluid passageway 12 into a fluid passageway 62 and out of an air
vent 65. The air vent 65 may be an air filter that allows passage
of air from the fluid passageway 65 and out of the catheter hub 10.
A suitable air vent 65 for use with the catheterization assembly
200 may be constructed from a variety of hydrophobic membranes and
filters, including but not limited to Pall Specialty Materials:
Emflon PTFE Membranes; Hydrolon Nylon 6,6 Membrane; Supor R
Membrane; Pallflex 8E Medium; Pallflex 70 Medium; Pallflex 40
Medium; Pallflex TV2 Medium; Pallflex TX4 Medium; and Pallflex TS6
Medium.
[0063] In this embodiment, when the user primes the catheterization
assembly 200, the user first introduces a priming fluid into the
catheter hub 10 as described above. The priming fluid in this
embodiment flows through the valve 30, tube 40, fluid passageway
14, fluid passageway 12, fills the area around the needle 45, and
enters the fluid passageway 62. As the priming fluid fills the
fluid passageways present in the catheter hub 10, the air vent 65
allows the air in the catheter hub 10 to vent out. When the priming
fluid enters the fluid passageway 62, it eventually comes into
contact with, and thereby seals, the air vent 65. Hence, an
ordinary technician in the relevant technology will appreciate that
the air vent 65 is configured to allow passage of air but not of
fluids out of the catheter hub 10.
[0064] The cannula 60 preferably remains in place until the
catheterization assembly 200 is inserted into the patient's
vascular system. The person of ordinary skill in the relevant
technology will appreciate that in this embodiment the cannula 60
with its vent 65 may be removed safely in a single motion with the
removal of needle 45.
[0065] FIG. 4 illustrates schematically a catheterization assembly
300 in accordance with another embodiment of the invention. The
catheterization assembly 300 comprises a catheter hub 10 that is in
fluid communication with a catheter 20 and a valve 30. In some
embodiments, a tube 40 provides a fluid passageway for fluid
communication between the catheter hub 10 and the valve 30.
Additionally, in some embodiments of the catheterization assembly
300, the catheter hub 10 is preferably permanently attached to the
valve 30 and the catheter 20. The catheterization assembly 300 may
also include a sealing member 50 that acts as a normally-closed,
self-sealing valve that prevents passage of fluid from the fluid
passageway 12 out of the catheter hub 10. The sealing member 50 is
preferably, but not necessarily, also permanently attached to the
catheter hub 10 at the proximal end of the fluid passageway 12. The
catheter hub 10, catheter 20, valve 30, tube 40, sealing member 50,
and fluid passageways 12 and 14 are of similar form and
construction as those described above with reference to
catheterization assembly 100.
[0066] As shown in FIG. 4, the catheterization assembly 300 may
also comprise a catheter hub 10 having a fluid passageway 16 that
is fluid communication with the fluid passageway 12. The fluid
passageway 16 terminates at an air vent 65, which performs the same
function as air vent 65 of FIG. 3, namely air vent 65 permits
passage of air out of the catheter hub 10 but does not allow entry
or exit of other substances into or out of the catheter hub 10.
[0067] Similarly to catheterization assembly 200, when the user
primes the catheterization assembly 300, the user first introduces
a priming fluid into the catheter hub 10 as described above. The
priming fluid in this embodiment flows through the valve 30, tube
40, fluid passageway 14, fluid passageway 12, fills the area around
the needle 45, and enters the fluid passageway 16. As the priming
fluid fills the fluid passageways present in the catheter hub 10,
the air vent 65 allows the air in the catheter hub 10 to vent out.
When the priming fluid enters the fluid passageway 16, it
eventually comes into contact with, and thereby seals, the air vent
65. The catheter hub 10 is, thus, configured with an integral fluid
passageway 16 that allows passage of air out of the catheter hub 10
before insertion of the catheter 20 into a patient's vein.
[0068] Another feature of the invention is a method of
manufacturing a catheterization assembly, e.g., catheterization
assembly 100 of FIG. 2, having a valve 30 fixedly attached to a
catheter hub 10. The method comprises permanently attaching a
catheter 20 at the distal end of a catheter hub 10. In some
embodiments, the catheter 20 is welded to the catheter hub 10; in
other embodiments, the catheter 20 is bonded chemically to the
catheter hub 10. The method further comprises welding or chemically
bonding a valve 30 directly to the catheter hub 10. In some
embodiments, a tube 40 or other fluid carrier having suitable end
connections, is welded or chemically bonded to the catheter hub 10
at one end and to the valve 30 at the other end. Moreover, in some
embodiments a sealing member 50 is permanently welded, chemically
bonded, or press fit to the catheter hub 10 at the proximal end of
the fluid passageway 12. An ordinary technician will recognize that
these permanent attachments may be accomplished by bonding, gluing,
ultrasonically welding, or even by providing compression fits. Any
manner of providing an attachment that is not meant to be
disassembled in normal use is suitable for the purposes of the
invention.
[0069] Another aspect of the invention concerns a method that
facilitates delivering or aspirating fluid to or from a patient.
This method employs a catheterization assembly as describe above.
The method includes introducing into a vein of a patient a catheter
20 that is permanently attached to a catheter hub 10, which
catheter hub 10 is itself permanently attached to a valve 30. A
user may employ an introducer, such as needle 45, to create an
entry into the vein of a patient for the catheter 20. The user may
pass the introducer through the catheter hub 10, into the catheter
20, and pierce the patient's vein. After the user places the
catheter 20 in the patient's vein, the user pulls the introducer
out of the catheter hub 10, through a sealing member 50, without
any fluids exiting the catheter hub 10. After the catheterization
assembly 100 is in place, the user may deliver to and/or remove
fluids from a patient via the valve 30. Hence, the user employs a
catheterization assembly having a catheter hub 10 with multiple
ports for delivering or retrieving fluids from a patient. Moreover,
as should be apparent to a person of ordinary skill in the art, the
catheterization assemblies described do not require the health care
worker to separately provide and attach other components to a
catheter and its hub during catheterization because the
catheterization assemblies of the invention are pre-assembled with
the components (e.g., tube 40 and valve 30) typically used in
catheterization.
[0070] It will be apparent to a person of ordinary skill that the
catheterization assemblies and methods described here reduce the
transmission of bloodborne infections from patients to health care
workers. When using known catheterization devices, blood often
seeps out from the catheterization device. By permanently and
integrally attaching a valve to a catheter hub at one port of the
catheter hub, and by providing a sealing member at a different port
of the catheter hub that is for insertion of a catheter introducer
(e.g., a needle), fluids are blocked from exiting the
catheterization assembly. Accordingly, the health care worker
employing the catheterization assembly of the invention is
protected from exposure to patient blood and other fluids.
Additionally, because the catheterization assemblies of the
invention may include needle-free valves, when fluid such as
medication is delivered through the needle-free valve or when fluid
is aspirated from the needle-free valve, the health care worker is
not exposed to needles or the dangers posed by needle sticks. Thus,
the risk of transmission of bloodborne pathogens such as HIV,
various strains of hepatitis, etc. is reduced or eliminated.
[0071] While the above detailed description has shown, described,
and pointed out novel features of the catheterization assembly and
related methods as applied to various embodiments, it will be
understood that various omissions, substitutions, and changes in
the form and details of the device or processes illustrated may be
made by those skilled in the art without departing from the spirit
of the invention. The scope of the invention is indicated by the
appended claims rather than by the foregoing description. All
changes which come within the meaning and range of equivalency of
the claims are to be embraced within their scope.
* * * * *