Vascular Access & Central lines
Obtaining appropriate vascular access is a fundamental challenge in hospital medicine, as it is the basis for many diagnostic tests and therapies. Intravenous (IV) access is required for volume resuscitation, medication administration, blood product delivery, and phlebotomy for diagnostic studies. "Advanced" access, including dialysis catheters, large-bore catheters for pheresis, and surgically implanted ports for chemotherapy, are mentioned briefly but are beyond the scope of this chapter.
The hospitalist must work with nursing, IV teams, and other services to ensure that each patient has appropriate, safe, and durable IV access, while minimizing the associated risks of obtaining and maintaining such access. This chapter is a resource to for the hospitalist in recognizing the level of intravenous access required, identifying team members to help with access, and ultimately ensuring that appropriate access is obtained and maintained. Arterial access is dealt with in a separate chapter.
II. Identify the Goal Behavior.
The hospitalist must balance the risks and discomfort of obtaining and maintaining vascular access while ensuring that an appropriate level of access is obtained to satisfy the emerging medical needs of the patient.
Obtain vascular access that is only as invasive/aggressive as needed.
Obtain access with a minimum of patient discomfort.
Minimize risk of infection or complications, and manage them when they arise.
Maintain access throughout hospitalization, replacing and re-evaluating as needed.
III. Describe a Step-by-Step approach/method to this problem.
Step 1: Determine the appropriate level of access.
Peripheral IV access is the default choice unless therapeutic or hemodynamic circumstances warrant advanced access. The placement of a more invasive line should be based on advanced indications. Peripheral access remains one of the most effective means of volume resuscitation.
If the answer to any of the following questions is "yes," peripheral access is not optimal, and more invasive access should be obtained.
Does the patient require pressors to maintain blood pressure after volume resuscitation?
Is the patient hemodynamically unstable?
If the answer to either of these questions is yes, consider a triple lumen catheter for central access.
Does the patient require long-term intravenous medications (such as antibiotics)?
Is peripheral access required but difficult to maintain?
Are repeat blood draws necessary over a period of days to weeks but difficult to obtain?
Does the patient require total parenteral nutrition?
If the answer to any of these four questions is yes, consider a peripherally inserted central catheter (PICC) line.
Does the patient have massive blood loss or expected ongoing blood loss (e.g., from trauma, hemorrhage, severe GI bleed)?
If the answer is yes, consider ICU placement of a large-bore catheter +/- triple lumen catheter for central access.
Does the patient require high-volume blood shifting (e.g., dialysis, pheresis, exchange transfusion)?
If the answer is yes, consider advanced central line access.
Is the patient bacteremic?
Is there a high clinical probability of bacteremia?
If the answer to either of these questions is yes, consider peripheral IV (or triple lumen catheter if patient is unstable), and change as soon as able. Avoid use of PICC/midline if possible.
Step 2: Choose the access type based on the questions above and tailored by your facility policies.
Peripheral intravenous catheters should always be the first-line consideration for vascular access because of their ease of insertion and minimal risk of complications, such as pain, infection or thrombosis. Check your institutional policy regarding duration; a typical lifespan of a peripheral IV is 72 hours. Peripheral IVs are available in sizes from 14-gauge to 22-gauge. Larger 14-18 gauges are suitable for high rates of volume administration, and possibly phlebotomy. The smaller 20-22 gauges are often easier to place but have slower flow rates and are not suitable for phlebotomy because of the high rate of hemolysis. See "Common pitfalls" for a discussion of gauge, French and catheter flow rates.
Central Venous Catheter: Triple Lumen
Central venous access allows for the administration of medications with higher risks for causing phlebitis or tissue destruction should the medicine extravasate from the vein. Examples are pressor medications, chemotherapy, high concentrations of potassium, and TPN. A triple lumen catheter provides three separate points for administration, allowing for multiple non-compatible medications to be delivered to the patient simultaneously.
Given the larger size and catheter-dwelling duration, these lines present with higher risk of bloodstream infection than their peripheral counterparts. Triple lumen catheters are effectively very long, 16-gauge IVs, making them a poor choice for volume resuscitation compared to peripheral IVs or larger-bore central access.
A midline is a long peripheral IV catheter inserted to 20 cm (8 inches) for intermediate-length peripheral access (1-6 weeks). It is useful for non-central IV medication administration, such as long-term antibiotics. Because of the length and relatively collapsible lumen, midlines are ill-suited for phlebotomy.
A PICC provides central access (the goal tip-placement target is distal SVC to cavo-atrial junction) and may be used for an extended duration (up to 8 weeks); PICC lines are also for serial phlebotomy.
Other Advanced Access:
Surgically placed lines: Hickman lines, subcutaneous port catheter
Dialysis Line: temporary or tunneled
Advanced access lines are often placed for a specific indication, such as chemotherapy administration, pheresis, or hemodialysis. It is often important to be aware of these lines, as hospitalist patients may already have had them placed by another physician. The care and management of these lines are more involved than they are with other types of access, and it is often necessary to discuss the conditions under which the lines should be accessed with the placing physicians. Hemodialysis lines are exceptional for volume resuscitation in an emergency.
Intraosseous Access Devices
These devices are generally for field/ACLS-type resuscitation only and are currently considered temporary access. Establish alternate access as soon as possible.
Step 3: Determine who should place the line per your hospital policy.
Do not hesitate to ask for help if you are not comfortable placing the line. The more advanced types of access almost always require specialized physician intervention. Several resources, including nurses, IV teams or PICC teams, hospitalists, interventional radiologists, surgeons, pulmonary/critical care physicians, and anesthesiologists, are available at most institutions to help you obtain appropriate access:
Step 4: Ensure no contraindications exist
Contraindications to IV placement at a given site:
Ability to obtain suitable, less invasive access
Overlying skin/soft tissue infection
Presence of an arterio-venous graft on the selected side
History of lymph node dissection on the selected side
Thrombus in the target vessel
Pacemaker on the selected side (for central access)
General Cautions: Thrombocytopenia (platelets <30,000), Coagulopathy (INR >3.0)
Step 5: Obtain Consent
Discuss the risks and benefits of the procedure with the patient (or health care proxy) and obtain verbal consent for peripheral access or written informed consent for central access per institutional policy.
Step 6: Obtain Venous Access
Peripheral IV placement:
Select the site: Peripheral lines should be placed in the most distal upper extremity veins suitable for cannulation. Avoid cannulating across joints, as this often requires stabilizing the joint and minimizes patient comfort. Move proximally if you are unable to obtain distal veins. Do not attempt to cannulate distal to a failed proximal attempt, as extravasation may occur. Remember that the external jugular vein is an effective "last resort" site for peripheral access. Lower extremity IVs are less favored because venous valves, movement and higher infection risk.
Gather supplies: Gather catheter, tape, personal protective gear, and alcohol wipes, and don appropriate personal protective gear.
Cleanse the skin overlying the site. Alcohol is sufficient.
Apply a tourniquet proximal to the selected site.
Position the patient's arm. Palpate the vein.
Slowly insert the needle at a 30-45 degree angle directly over the palpable vein. Advance gradually until a flash of blood is seen. At this point, decrease the angle of the catheter to about 15 degrees and then advance the catheter over the needle into the vein. Remove the needle. Remove the tourniquet.
Ensure patency by flushing with 10cc of normal saline. Secure the catheter in place with tape.
Central Line placement:
--Select the site: Central lines are generally placed in the internal jugular vein, the subclavian vein, or femoral veins. The subclavian vein is the preferred placement site to maximize patient comfort and minimize infection risk, but it has a higher risk of pneumothorax during placement. The internal jugular vein is less comfortable for the patient with a higher infection risk, but it is safer during placement. Femoral vein catheters have a higher infection and thrombosis risk, are less comfortable, and should be used only when a patient is not compliant and the risk of pneumothorax is significant. If a patient has dialysis in his or her future, check with your renal team as to which veins to "save."
New England Journal of Medicine instructional videos for central line placement: Subclavian vein: http://youtu.be/YsC1HDCu-oQ; Internal jugular vein: http://youtu.be/iXTnFmhCfLs; Femoral vein with ultrasound: http://youtu.be/g2xqblYFBgI
--Gather supplies: Gather sterile gloves, gown, cap, and mask with face fluid shield for each member of the insertion team. Gather ChloraPrep®, large sterile drape, lidocaine 1%, central line of your choosing (based on criteria above), small anesthetizing needle (25-gauge x 1”), “finder” needle (22-gauge x 1.5”), introducer needle (18-gauge x 2.5”): 18-gauge x 2.5” catheter over 20-gauge needle, J-tip guide wire (0.035” diameter x 45 cm), scalpel with no. 11 blade, two 5mL syringes for lidocaine administration and vein aspiration, 8.5 F vessel dilator, two sterile syringes of normal saline, two 2” x 2” gauze pads, two 4” x 4” gauze pads, suture with curved needle, disposable needle holder, TegadermTM.
Whenever possible, using an ultrasound is preferable for patient safety. Use of the ultrasound allows for accurate insertion with visualization of the vein, especially necessary in cases of difficult anatomy.
--Position the patient and bed (Subclavian & IJ): Place the patient in 15-30 degrees of Trendelenburg just prior to obtaining access; the resulting venous dilation from Trendelenburg lasts only minutes. Ensure the bed height is such that you are not bending over. For subclavian lines: a rolled towel, gown, or small pillow between the patient’s scapulae will make the clavicle more prominent. Turn the patient's head to the opposite side, arms at their side.
--Don personal protective gear, including sterile gown and gloves, facemask with eye shield, and cap.
--Prep and drape the area in the usual sterile fashion (using chlorhexidine swabs or equivalent).
--Obtain access (Subclavian: NEJM Video: http://www.nejm.org/doi/full/10.1056/NEJMvcm074357; internal jugular: NEJM video: http://www.nejm.org/doi/full/10.1056/NEJMvcm0810156)
Subclavian: Palpate the clavicle to where it bends anterior-poster. Once this bend is found, feel with your left thumb for the costoclavicular ligament with your left index finger in the suprasternal notch. If you can feel these landmarks, the subclavian vein should follow the line between your thumb and forefinger.
Internal Jugular: Palpate the triangle formed by the clavicle and each of the heads of the sternocleidomastoid muscle (SCM). Feel for the carotid artery as it runs medial and posterior to the vein. Valsalva may distend the vein and make it more easily identified.
Anesthetize the procedure area:
Using your 25-gauge (smaller) needle with a 5 mL syringe of lidocaine, first inject superficially to anesthetize the skin over the target site. Depending on the patient's size, you may then switch to a 22-gauge needle to inject more deeply, including the periosteum of the clavicle for the subclavian approach. The patient should be able to feel pressure but not the sharpness/pain of the needle when appropriate anesthesia is achieved.
Locate the vein with the introducer needle:
Subclavian: With your left hand in position as described, insert the finder needle with the syringe medial to your thumb. Aim cephalad and posterior toward your finger (on the suprasternal notch) and flat on the chest as possible. Advance the needle until you feel the clavicle (which you have anesthetized). Aspirate while advancing. Slowly advance the needle slightly cephalad until dark blood flows in easily. For air or bright blood, see Pitfalls.
Internal jugular: Use ultrasound whenever possible. First ensure that a sterile cover is used for the ultrasound. Use the ultrasound vascular probe to locate an area of the patient's neck where the Internal jugular vein appears to be largest, centered, and not superficial to the carotid artery. Once a window has been found, leave the ultrasound in place. Rather than looking at the screen, look at the patient and aim down at a 45-degree angle toward the center of the ultrasound probe.
If ultrasound is not available, use the landmarks described above to locate the vein, which is usually 1-3 centimeters deep. Holding loose skin taut will help with this process. Aim lateral first, as the carotid artery is medial. Use the introducer needle to help locate the vein. Aspirate while slowly advancing. Cannulation of the vein generally occurs at a depth of 1-3 cm. If the vein is not found, gently withdraw while aspirating (the vein is sometimes cannulated during withdrawal) until the needle tip is just below the skin surface, and re-angle 5-10 degrees medial to the initial landmarks.
General Insertion tips: When you are certain the needle is in the lumen of the vein, grasp the needle with your thumb and middle finger and detach the syringe with your dominant hand, taking care not to advance or withdraw the needle. Occlude the hub of the needle with your forefinger to prevent an air embolus.
Insert the guidewire:
Still holding the needle in place while moving as little as possible, use your free hand to feed the guidewire into the vein, with the hooked portion facing medially. Never force the guidewire, and never lose your grasp on it.
Remove the needle, keeping the guidewire in place.
Dilate and cut the skin:
Once the needle is removed, place the scalpel adjacent to the guidewire with the blade facing out from the wire. Push toward the skin to ensure an opening large enough for the dilator to pass through. The dilatory should meet minimal resistance, and most of that resistance should be from the skin. Once dilated; remove the dilator.
Insert the line:
Still holding the wire, pass the catheter. (Ensure that the caps are not on so as to not trap your guidewire.). Insert the catheter to the hub and then remove the guidewire with your free hand. Once the guidewire is removed, recap the central line ports.
Confirm patency and effectiveness by flushing the catheter, and then secure tubing.
--Suture the catheter in place
--Confirm catheter placement and lack of pneumothorax via X-ray, and adjust as needed.
--Dress and date the catheter.
--Monitor the site for evidence of complication (infection, infiltration, thrombosis). Remove as soon as clinically feasible.
If the answer to either of these questions is yes, consider a triple lumen catheter for central access.
IV. Common Pitfalls
Take off the tourniquet! Leaving the tourniquet on is a common reason why peripheral IVs fail.
Many central venous access devices are Heparin-coated, as indicated by often small, non-obvious warnings on the packages. Heparin-coated lines can be as source of Heparin-induced thrombocytopenia (HIT) and its related complications, so they should be removed in patients with suspected HIT.
What is Gauge? What is French?
Gauge is the inverse of the internal diameter of the catheter. Therefore, a 20-gauge catheter has an internal diameter of 1/20th of an inch. Diameters (and flow rates) increase as gauge size decreases.
French, by contrast, is three times the internal catheter diameter in millimeters. A 9 French catheter has a 3 mm internal diameter. Diameters (and flow rates) increase as French size increases.
Examples of IV size and flow rates held length constant at 30mm:
20 gauge: 60 mL/min or 1L in 16:40
18 gauge: 105 mL/min or 1L in 9:30
16 gauge: 220 mL/min or 1L in 4:30
Iodinated contrast for diagnostic/radiologic purposes is often injected at high pressure into catheters. It is important to check with your radiology team regarding what access will withstand the high pressure. Central lines are often too fragile; peripheral lines of a required size (larger than 20-gauge) are often required.
Risks of Access
Catheter-associated blood stream infections
Bleeding/arterial injury: approximately 3 percent with the internal jugular approach
Localized hematoma, hemothorax
Pneumothorax: approximately 3 percent with the subclavian approach
Infection: Insertion site infection, thrombophlebitis, bacteremia, sepsis, cellulitis
Embolization of clot, air, guidewire or catheter
Phlebitis or thrombosis of veins
Injury to neighboring nerves (phrenic, recurrent laryngeal)
Drawing Labs from Peripheral IVs
A common way to "blow the vein" is to draw peripheral blood for diagnostic purposes after an IV has been placed. Drawing peripheral blood is often acceptable on the initial stick, but subsequent pressurized draws often cause loss of IV functionality. This becomes less likely as the diameter increases, but it is still a risk with all peripheral IVs.
Central Line Troubleshooting
There are as many tricks as there are physicians:
Save Trendelenburg until the last possible minute.
Ensure that the finder needle is not too tightly secured to the finder syringe; moving the needle inside the vein while trying to separate the two can cause hematoma or loss of access.
Blood clots: Repeated attempts will often fail because of clotted blood within the finder needle. Flush regularly if multiple attempts are required.
Air embolus can occur should your patient take a deep breath and suck air into the catheter or suddenly decompensate. If this occurs, quickly occlude the lumen and attempt to aspirate air through it. Immediately turn the patient to the left lateral decubitus position with the head down.
Do not dilate bright red blood: If you aspirate a high volume of bright red blood, it is likely you are in the carotid artery. Do NOT dilate this artery. Instead, remove your needle and apply pressure for fifteen minutes.
Make a big enough skin nick. Often the trauma of forcing a wide catheter into a small skin nick can compromise the entire procedure.
If you cannot thread the guidewire, do NOT force it, as it is perfectly capable of rupturing the vessels through which it travels. The catheter and dilator are less capable of doing so, but still do not force a catheter.
Troubleshooting Non-functioning Catheters
If a peripheral catheter appears to be extravasating or not functioning, it is best to remove it. If a central line appears to have one lumen non-functioning, possible solutions include tPa administration, citric acid, or ethanol injections to remove accumulated debris.
V. National Standards, Core Indicators and Quality Measures
Joint Commission's National Patient Safety Goal NPSG.07.04.01:
"Use proven guidelines to prevent infection of the blood from central line"
CDC Guidelines: http://www.cdc.gov/hicpac/pdf/guidelines/bsi-guidelines-2011.pdf
IHI Central Line Bundle: http://www.ihi.org/IHI/topics/criticalcare/intensivecare/changes/implementthecentrallinebundle.htm
VI. What is the evidence?
Braner, DAV. "Videos in Clinical Medicine: Central Venous Catheterization — Subclavian Vein.". N Engl J Med. vol. 357. 2007. pp. e26.
Chesnutt, M,, Dewar, T,, Locksley, R. "Office and Bedside Procedures". East Norwalk, Conn.,. 1992.
Frank, RL, Basow,, DS (Ed), UpToDate,, Waltham,, MA. "Peripheral venous access in adults". 2012.
Graham, AS. "Videos in Clinical Medicine. Central Venous Catheterization". N Engl J Med 2007. vol. 356. 2007.
Heffner, AC, Basow,, DS (Ed), UpToDate,, Waltham,, MA. "Placement of central venous catheters.". 2012.
Herts, BR. "Power Injection of Contrast Media Using Central Venous Catheters: Feasibility, Safety, and Efficacy.". AJR. vol. 176. 2001. pp. 447-453.
Ortega, R. "Videos in Clinical Medicine: Ultrasound-Guided Internal Jugular Vein Cannulation.". N Engl J Med. 2010. pp. 362-e57.
Pfenninger, J,, Fowler, G. "Procedures for Primary Care Physicians,". Mosby-Year Book, Inc. 1994.
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