In 2010, 2.6 million individuals received renal replacement therapy. Most of them were also receiving hemodialysis treatments. That number has since grown to 4 million, making knowledge of the procedure vital for healthcare practitioners.
Though catheter insertion is an important part of these treatments, clinicians may not be aware of when it should be inserted.
Hospital Procedures Consultants will give you the rundown on what it entails, when should you insert a dialysis catheter, and why ultrasound-guided central venous catheter placement is your best course of action.
When Should You Insert a Dialysis Catheter?
Hemodialysis is the most common form of dialysis, with a worldwide prevalence of 89%. As such, nephrologists must achieve preemptive vascular access approximately 6 months before the start of hemodialysis treatment to allow maturation and have the right type of access. This can significantly influence patients’ survival rates.
Additionally, for patients undergoing continuous renal replacement therapy, it’s important to consider circuit flow interruptions. It can lead to decreased dose or clearance delivered, increased loss of blood products, altered medication dosing, inconsistent fluid removal, and increased infection risk which all impact the patient.
Exploring the Types of Access Used in Hemodialysis
Here’s a look at the three main types of access employed in hemodialysis:
- Arteriovenous grafts – associated with early maturation, ease of creation and needling, and widespread availability. However, it has poor patency.
- Arteriovenous fistulas – considered the gold standard. It is associated with a longer maturation time but can decrease the risk of infection, hospitalizations, central venous stenosis, and mortality.
- Central venous catheters – approximately 80% of patients with end-stage kidney disease in the U.S. have hemodialysis-CVC. It’s a reasonable long-term option but can have serious placement-related complications.
There are also subtypes within these categories.
Which Type of Access Is the Best?
Central venous catheters (CVCs) can provide rapid extracorporeal blood flow ranging from 300 to 400 mL/min for 3 to 4 hours 3 times a week with minimal complications.
This makes them an indispensable access method for hemodialysis patients, particularly those with end-stage kidney disease. CVC is also needed for access if and when the permanent hemodialysis access starts malfunctioning or becomes infected.
Moreover, nephrologists can initiate a dialysis catheter when the patient’s (who has end-stage renal disease) creatinine clearance is less than 10 mL/min.
Temporary hemodialysis catheter access is necessary to initiate emergent dialysis but it is urgent to maintain full sterile precautions during insertion to minimize catheter-related bloodstream infections. Compared with dialysis through an AV fistula, dialysis through a temporary dialysis catheter has the highest incidence of infection, ranging from 1.6 to 7.7 bacteremic episodes per 1,000 catheter days.
This is backed by a 2017 prospective cohort study over a 16-month period involving 154 patients on renal replacement therapy (AKI-RRT). It suggested that patients who received tunneled dialysis catheters (TDC) had significantly better RRT delivery and a lower median of interruptions per catheter compared to non-tunneled variants, both had continuous venovenous hemofiltration and intermittent hemodialysis.
The findings are in contrast with the general stance on dialysis catheters, which recommends initiating RRT in patients with AKI via an uncuffed, non-tunneled dialysis catheter. This is recommended to see if permanent hemodialysis will be needed via a TDC or whether renal function would normalize precluding need for long-term dialysis.
Where To Insert the Dialysis Catheter?
Functioning vascular access is important for the performance of hemodialysis. This is because once a catheter has been inserted, options become much more limited should the catheter fail to function. In fact, prior catheter use for hemodialysis was associated with a 250% and 140% increase in loss of patency, a 130% increase in infection, and a 79% and 120% increase in mortality for autogenous fistulas and prosthetic grafts, respectively.
While there are three types of access for central venous catheters, it is best to avoid using the subclavian vein for the placement of the dialysis catheter. Doing so may affect flow rates and heighten the risk of central venous stenosis. It could also compromise the usability of arteriovenous access for dialysis and lead to future problems.
A clinician’s best options are the internal jugular and femoral veins. However, since there is a risk of arterial puncture during vein cannulation, it’s best to use a US-guided catheter to the internal jugular vein to reduce the risk of complications. Catheter placement experience and practice also help as does the use of maximum barrier precautions and chlorhexidine (2%) skin antiseptic.
Indications for Acute Hemodialysis
The mnemonic AEIOU can help you remember the indications for acute hemodialysis:
- A – Acidosis, characterized by a pH of 7.3 or lower refractory to sodium bicarbonate tablets.
- E – Electrolytes, principally severe hyperkalemia, which may cause life-threatening cardiac arrhythmias, muscle weakness, or paralysis.
- I – Ingestions or intoxications. To recall the drugs and toxins that can be removed with dialysis with ease, remember the mnemonic SLIME: Salicylates, Lithium, Isopropyl alcohol, Methanol, and Ethylene glycol.
- O – Overload of fluid. When a person can no longer produce urine (which happens to most people on dialysis), fluids build up in the body, causing pulmonary edema or pleural effusions that lead to shortness of breath and hypoxia.
- U – Uremia, which develops most commonly in chronic and end-stage renal disease (ESRD). It can affect the central nervous system, causing encephalopathy, as well as nausea, vomiting, anorexia, fatigue, muscle weakness and cramps, malaise, polyneuritis, uremic frost, and headache, to name a few symptoms.
In the event of pharmacological poisonings, which can have serious adverse reactions and can even cause death, the use of renal replacement therapy must be considered. It can be used to manage toxicities on a case-by-case basis after supportive care fails. This includes patients with cerebral edema (patients with focal neurologic deficits, papilledema, imaging findings, altered mental status, etc.), those with valproic acid levels above 1,300 mg/L, and hemodynamic instability.
Though effective, the available data is limited to case studies.
Brush Up on Your Dialysis Catheter Insertion Skills With Hospital Procedures Consultants
It is recommended that arteriovenous fistulas be considered the first line of access as it has proven to have superior clinical and economic advantages. However, if your expertise and experience indicate that catheter placement is a better option for a specific case, then it pays to know the proper insertion techniques.
Hospital Procedures Consultants offers many courses, such as Femoral Line Course, Internal Jugular Line Course, and Subclavian Line Course. These can help your familiarity with the best catheter placements for hemodialysis.
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