Why Kidney disease patient need regular dialysis?

When you have End Stage Kidney Disease you have to undergo regular hemodialysis. This is to give the continuous kidney functions outside the body. This regular haemodialysis will ensure the proper execratory and other regulatory functions of the kidney.

However the haemodialysis is not a one time process. You have to repeat the dialysis in a regular basis like 3 times a weeks, 2 times a week or else. This regular haemodialysis is done at a hemodialysis center or at the patients own home.

Even in a situation like covid 19 , it is necessary part to continue haemodialysis without interruption.

How to be safe as a hemodialysis patient during COVID 19

Make sure you have safe dialysis center

When you are selecting or continue the hemodialysis during covid pandemic it is essential to find a place with proper infection prevention procedures. Specially it it has separate rooms for the each patient it will be beneficial.

Do not use public transport

Some people prefer the public transport than the private transport systems. This is not a good option for a CKD patient to have there transport during COVID 19. As they are less immune, they can get infected easily. Additionally they have a high mortality rate too.

Therefore find a near place for your haemodialysis. Use a private vehicle to reach the dialysis center.

Use facemasks

Face-mask is an essential item for covid prevention. When you are travelling in a public, you always need to wear a mask and follow necessary infection prevention protocols.

However if you use separate dialysis room, you do not need to wear a mask. But if its a common room, you have to wear a mask.

Practice proper hand washing techniques

Hand washing is alos a mandotory part of covid prevention. When you go away from your home, it is essential to practice hand washing. In addition use hand washing techniques before and after dialysis session.

Inform health staff on warning signs

When you use common dialysis facilities, you are also bound to protect the health of other dialysis patients too. Therefore it is necessary to inform the dialysis center about your warning sings of COVID 19 infection like fever, cough, cold etc.

Avoid the crowded places

When you are continue haemodialysis during covid 19 infection, it is necessary to minimize the exposure to the public. This include all social gatherings, visiting to the public places and etc.

This will avoid unnecessary troubles during covid 19 pandemic and ensure the safe hemodialysis.

How to safeguard the hemodialysis patients as health staff ?

In the corona pandemic we have to be safe whenever we are touching or dealing with patients. You may be doctor, dialysis nurse or dialysis technician attached to a dialysis center, whatever the occupation, you all have to be safe whenever possible.

As an staff member of the dialysis center, you have the responsibility to avoid the spread of covid through your dialysis center. Following guide will help you to continue hemodialysis during covid 19 pandemic.

Always screen the patients before entering to the dialysis center

Whenever a new patient or regular patient come for dialysis all of them has to undergo proper screening questioner to select the risk group of patients. The screening questioner should be covering recent visits, warning symptoms and etc.

Use separate rooms for risk groups

In some dialysis centers, they have the separate dialysis rooms. All the risk group of patients awaiting for dialysis has to inserted to these rooms. This will avoid cross contamination of corona infection.

Always use proper safety precautions during dialysis

Always you have to wear a mask, practice hand washing techniques and etc.

Use PPE when necessary during haemodialysis

When you continue the haemodialysis of the risk group of patients for COVID 19, it is always advisable to use a Personal Protective equipment (PPE). PPE will save you from corona infection while continue haemodialysis during corona pandemic.

Reference

https://www.cdc.gov/coronavirus/2019-ncov/hcp/dialysis.html

What is CKD?

Our kidney has lot of physiologically important functions like removal of waste products, production of urine and etc. However, there are some instances when your kidneys fail to achieve the expected level of functions. The long-term inability to achieve such is defined as CKD. Although there may be structural abnormality of kidneys in Chronic Kidney Disease, CKD is commonly the functional abnormality. However later you would have structural changes too.

What is GFR and eGFR?

GFR – Glomerular Filtration Rate is the key indicator of someones kidney functions. This indicate the average rate of solute filtration from the glomeruli. It is calculated by the filtration rate of Creatinine. Therefore GFR is depend on someones age, sex and race. eGFR is a mathematically calculated glomerular filtration rate. The calculated eGFR value is used for the eGFR staging of CKD.

The calculation of eGFR is done with the help of standard calculation formulae. It uses age, gender and race for this calculations. The result is given for the body surface area. The normal eGFR is more than 90ml/min/1.73m² .

eGFR Staging of CKD (Chronic Kidney Disease)

The usual CKD staging has 5 main stages. It is stage 1 to stage 5. The stage 1 having minimum or no reduction of kidney functions while stage 5 has almost zero kidney function.

Normal eGFR

Usually eGFR for normal person is above 90 (>90ml/min/1.73m2). If you have normal eGFR, you have a good kidney function. However the normal GFR is vary according to age. Usually the normal level of GFR reduce with age.

20–29 116

  30–39 107

  40–49 99

 50–59 93

  60–69 85

  70+ 75

Stage 1 CKD

Stage 1 CKD is also can called “Early stage CKD”. Here there may be some features of Chronic Kidney Diasese, however the eGFR remains above the level of 90. These patients may have albumin urea while they maintain the normal eGFR levels.

Stage 2 CKD

When you have stage 2 CKD, there is a minimum reduction in kidney functions. The GFR is between 60 to 89. Although the impairment of kidney function is minimal, there may be features of microalbunurea.

Stage 3 CKD

Stage 3 CKD indicate a moderate to severe impairment of renal functions. When you have stage 3, the glomerular filtration rate remain between 30 to 60. There is a chance of oedema. At the stage 3 CKD you need a care of a Nephrologist. According to the eGFR staging of CKD, stage 3 is seperated to two sub stages. Those are stage 3A and stage 3B.

Stage 3A

Chronic Kidney Disease of Stage 3A have GFR between 45 to 60. In this stage of CKD, the reduction of kidney function remains in mild to moderate levels.

Stage 3B

Stage 3B CKD has a Glomerular Filtration Rate of 30 to 44. At the stage 3B CKD, you disease getting irreversible and there is a rapid deterioration of renal functions. Therefore you need a proper care by a Nephrology team at this stage.

Stage 4

CKD stage 4 is defined as severe limitation of renal functions. The range of glomerular filtation is 15 to 29. Usually there is a significant reduction of urine out put. There is a gross oedema and other features of CKD. Then a patient diagnosed with stage 4 CKD, they need to counselling on future dialysis or other renal replacement therapy options.In addition they may need to send for creation of vascular access, if they plan to proceed with haemodialysis.

Stage 5

According to the eGFR staging of CKD, stage 5 Chronic Kidney Disease has GFR of less than 15. These patients have severe impairment of renal functions. Some patients have almost nil urine output. According to the guidelines of management of CKD, stage 5 CKD patients need dialysis.

End Stage Kidney Disease – ESKD

What is the End stage kidney diases (ESKD) according to the eGFR staging of CKD? This is other common question among kidney disease patients. Usually the stage 5 CKD is define as end stage kidney failure. However in some situations stage 4 also consider as end stage renal disease.

eGFR EPI staging of CKD

GFR is not always a reliable indicator in normal method of calculation. Therefore there is a recently introduced method of eGFR staging of CKD called eGFR EPI. eGFR epi indicates complex formula of epidemiological collaboration. This is more reliable method of CKD staging.

How to Check the eGFR levels

The diagnosis is Chronic kidney disease is done with assessment of kidney functions in two separate occasions in 3 months gap. The main investigation to diagnosis of chronic renal impairment is Serum Creatinine (S Cr) with eGFR test. This blood test will give you the amount of Serum creatinine and mathematically calculated eGFR. In addition we can perform a urine test to identify the red blood cells (RBC) and urine albumin levels.

Except for the grossly reduced eGFR values you cant diagnose CKD with high amount of serum creatinine levels.

Reference

1. Levey AS, Stevens LA, Schmid CH, et al. A new equation to estimate glomerular filtration rate [published correction appears in Ann Intern Med. 2011 Sep 20;155(6):408]. Ann Intern Med. 2009;150(9):604-612. doi:10.7326/0003-4819-150-9-200905050-00006

Why do we do dialysis in patients?

Your kidney have very important set of functions to maintain balance between lots of body functions. This includes excretion of waste products, removal of excess water from the body, maintain electrolyte balance, maintain acid base balance and etc.
If someone fail to maintain these kidney functions, they will be facing lot of problems
Eg:

• Accumulation of water in the lungs (Pleural effusion)
• Accumulation of water in abdomen (Ascites)
• Excess Potassium in the serum (Hyperkalemia)
• Reduced pH in the blood (Acidosis)

As most of above issues are life threatening timely dialysis is very important.

How need hemodialysis?

As mentioned, there are two groups of patients who need dialysis.

1. Patients with Chronic Kidney Diseases (CKD)
2. Acutely ill patient with Acute kidney injury (AKI)

Dialysis of CKD patients

Hemodialysis is one of the very important option in management of CKD patients. It will help to maintain most of the kidney functions.
This will ensure;

• Removal of excess fluid from the body
• Remove excess Potassium from the plasma
• Maintain acid base balance

Dialysis of AKI patients

There are patients who get Acute Kidney Injuries (AKI) following different incidents. Viper bites, Sepsis, Leptospirosis are some of them. In such situations some patients undergo urgent haemodialysis.

How to dialysis a patient?

When we say dialysis most of the time it represents hemodialysis than the peritoneal dialysis.
When we do haemodialysis, the basic of this process is to take blood out of the body, purify it and re transfuse into the body. But this is very complicated process than this.

Steps of hemodialysis

1. Prepare the dialysis machine
2. Heparinize the vascular set properly
3. Connect the patient through Vascular access to the dialysis machine
4. Adjust all parameters of dialysis including UF, BFR, Heparin dose and etc
5. Let blood go through the semipermeable membrane of the dialyzer
6. Re transfuse blood to the patient
7. Reinfuse the blood after completion of procedure
8. Disconnect the Vascular line
9. Await for hemostasis

Important parts of Dialysis procedure

What is dialyzer?

As I mentioned, dialysis is an artificial process. So to give you kidney functions artificially, there should be an artificial kidney. Dialyzer is the one doing the function of an artificial kidney in the dialysis machine.

The dialyzers are made of synthetic semi permeable membranes. These membranes are capable of providing selective permeability to some of the molecules while others do not get it.
So dialyzer is the most important part of the haemodialysis machine.

Vascular access

When you want to undergo haemodialysis, you need to have an access point. This may be a AV Fistula, AV Graft, Perm Cath or Temporary Catheter. So each have different abilities. You should select your vascular access depending on your future dialyzing plan, vascular structure and lots of other factors.

However if you are undergoing an urgent haemodialysis, you have to use a temporary femoral or neck vascular catheter.

The vascular access will ensure the adequate blood supply to the dialysis machine. Also it will return all the purified blood to body.

Water supply

In a dialysis we are doing an invasive procedure to ensure the renal functions of the patient. However if we do not use proper water for this process, patients ended up with lot of complications. Sepsis is one of them.

Therefore we use a water plant with reverse osmotic systems.
This includes both filtering capacity of unnecessary particles and germs.

Complications of Haemodialysis

Although haemodialysis is a very important and effective treatment method, it may have lot of complications.

1. Dialysis Disequilibrium Syndrome
2. Hypotention during dialysis
3. Hypoglycaemia
4. Headache
5. Fever
6. Infections
7. Bleeding from vascular access

Reference

https://www.ajkd.org/article/S0272-6386(05)00436-1/fulltext

Basic mechanism of dialysis

Before understating the dialysis disequilibrium syndrome, it is good to know the basics of dialysis and how it works on your body.

If your kidney get Acute Kidney Injury (AKI) or Chronic Kidney Disease (CKD), you may have to undergo a process called dialysis. What we do as dialysis is the providing of natural kidney functions by an artificial kidney attached to machine. The most important function of dialysis is the removal of waste products from the body like urea. In addition it help to maintain acid base balance and electrolyte balance of the body.

You can see more about dialysis here.

If you have understood this basic of dialysis, you might understand that urea is removed in each session of the dialysis.

Mechanism of dialysis disequilibrium syndrome (DDS)?

Osmotic pressure of our body is basically maintain by two particles. One is the Sodium (Na+). Other one is the Urea. Even though other electrolytes are affecting this process, only these two can give significant contribution to oncotic pressure.

As we mentioned we remove some amount of the urea with each dialysis. Therefore there is a reduction of osmotic pressure in the blood. When plasma osmotic pressure reduced, it can cause cells to take some fluid from plasma and keep the balance between them.

Same process occurs in the brain too. This will ultimately result in increased size (edema) in the brain cells. This cerebral edema can cause lot of neurological issues simply from headache to death at last. When the amount of removed urea is higher, the edema is higher and risk of dialysis disequilibrium syndrome is higher.

Who get the disequilibrium syndrome?

Dialysis induced disequilibrium syndrome (DDS) is commonly seen in patient who undergoes their 1st series of dialysis. However it can also be seen in other CKD patients too. Some studies show that it is common in patients who miss their dialysis sessions.In addition it can present in some patients who undergoes dialysis or CRRT following acute kidney injury.

Symptoms and signs of disequilibrium syndrome

1. Headache
2. Nausea
3. Dizziness
4. Confusion
5. Visual disturbance
6. Tremor
7. Seizures
8. Coma
   
   
   

How to prevent disequilibrium syndrome

Few decades ago, DDS is one of the common issues during dialysis. However with the development of the Nephrology and dialysis care, the disequilibrium syndrome has become a rare condition among the patients with Chronic Kidney Disease. Even though the dialysis disequilibrium syndrome is a rare complication, this should be considered as on of the serious complication of dialysis.

1. Initiate the dialysis with short cycles
   Usual hemodialysis session are continue upto 4 to 5 hours. However at the initiation of the dialysis, it is advice to limit the duration of dialysis for few hours. Usually 2.5hours – 3hours as maximum. As a result the risk of sudden reduction of urea is rare.
   
2. Use low blood flow rate
   When you dialysis, you can adjust the blood flow rate though the machine. Higher the rate of blood purification, higher the risk dialysis disequilibrium syndrome. Therefore you can try with a blood flow rate of 100 – 150 in initial dialysis sessions.
   
3. Monitor the Urea Reduction Ratio
   Usually you can monitor the urea reduction rate with pre and post dialysis blood urea samples. So if the URR is high, you can reduce the other parameters in future dialysis.
   
4. Initiate with low Ultrafiltrate (UF)
   In each dialysis session, we remove some amount of water from the body. When the volume of blood reduced, it cause sudden imbalance on osmolality. This also can lead to DDS. Therefore use low UF in early dialysis sessions.
   
   
   

Summery

As a summery dialysis disequilibrium syndrome (DDS) is not a common complication in novel Nephrology and dialysis care. However it was a common complication in history of hemodialysis. Why is this so important? Importance of dialysis disequilibrium syndrome is that its severe neurological complication. These can cause even sudden death. Therefore we have to take necessary precautions to prevent this condition during dialysis.

Reference articles

1. Zepeda-Orozco, D., & Quigley, R. (2012). Dialysis disequilibrium syndrome. Pediatric nephrology (Berlin, Germany), 27(12), 2205–2211.
   https://doi.org/10.1007/s00467-012-2199-4
   
2. S.M.Silver MD, R.H.Sterns MD, M.L.Halperin MD, Brain swelling after dialysis: Old urea or New Osmoles? American Journal of Kidney Diseases, Volume 28, Issue 1, July 1996, Pages 1-13
   https://doi.org/10.1016/S0272-6386(96)90124-9

What is AV Graft?

AV graft or Arterio Venous Graft means an artificial connection between arterial line and the venous line. We use an artificial hollow material to create the surgical connection between two vessels. Usually this connection is created in elbow pit.

When to use the AV graft?

As we mentioned earlier, Av graft is not the most effective method of permanent vascular access for haemodialysis. However in some special situations, it is the first choice as a vascular access for dialysis.

1. Patient with inadequate venous access.
2. Patient who need an access soon.
   
   
   

Advantages of AV graft

Can use for patient need urgent regular haemodialysis
When you use an AV fistula for dialysis, you may have to wait for another 3 -6 month to maturity of the fistula site.However Arterio venous graft do not take that much of time to initiation of the dialysis. Usually we can start the haemodialysis after 1 month of the surgery. This is due to the fast maturity of the graft site.

Can use in patients with small blood vessels
Formation of AV fistula is very difficult surgery. Especially it is difficult procedure in wrist area. This is because of the absence of the large blood vessels in this area. However Arterio Venous graft can be used even in patients with vascular issues.

Need only the local anesthesia
This surgery is done under local anesthesia. In addition it is performed as a day surgery. Therefore you do not need long hospital stay.

Disadvantages of Arterio Venous Graft (AV Graft)

1. Insertion of artificial material to body
   We use synthetic material to connect two blood vessels together. Therefore we have to insert this synthetic material to the fistula site.
   
2. Risk of closure
   Although the AV fistula is often last a long time, there is a high chance of AV graft to get blocked by frequent blood clots.
   
3. Risk of infections
   As we have placed a synthetic material in our body, it is often tend to get infected. Therefore careful handling is necessary.
   
   
   

How to prepare for AV graft

When you are diagnosed as having Chronic Kidney Disease (CKD), your nephrologist would discuss about the future treatment options with you. You need hemodialysis only if you become a patient with End Stage Kidney Disease (ESKD). However there may be some other instance you need a dialysis in an acute set up.

When your condition is getting worse you have to select a kind of option from Kidney transplant, regular haemodialysis, CAPD or no treatments. If you select to dialyze for long time, you need to select your vascular access for dialysis. As we already have discussed Arterio Venous Fistula (AV Fistula) is the most commonly used vascular access. However there are options like Arterio Venous Graft (AV Graft) and Permanent catheter. Your vascular surgeon will decide your mode of vascular access depending on your conditions.

What is better option between hemodialysis and peritoneal dialysis?

This is probably will do after a proper vascular mapping and physical assessment.
Then you will give a date for the surgery probably as outpatient setting.
After 2 – 4 weeks of surgery your vascular surgeon will allow you to puncture the fistula site.

How to handle the AV graft during haemodialysis

Whenever an AV graft or AV fistula is created it should be handle in a proper way. Unless the lifespan of the vascular access get reduced. Then we have to reconstruct the vascular access or we have to recreate a vascular access.

You can apply some local anesthetic medication like lignocaine to reduce the pain during puncturing of the AV graft. But usage of subcutaneous lignocaine can increase the site of punctures.

You should handle the AV fistula in a way that minimum infections would be entered. Proper hand washing and disinfectants may be helpful to reduce the number of infections. Povidone Iodine solution can be used to clear the skin around the puncture site of the fistula.

You can use the same way as the puncture of the AV fistula for dialysis. That is puncturing of two sites of vein, one close to the arterial connection and other one way from the arterial connection.
You will use 16G AV Fistula needle for the procedure.

At the end of the dialysis session, you have to stop the bleeding with moderate pressure around the puncture site.

Proper use of heparin during dialysis will reduce the unnecessary bleeding will preventing the unnecessary clots.

Related articles

1. Michael Allon MD, Charmaine E. Lok MD, MSc, FRCPC, in Handbook of Dialysis Therapy (Fifth Edition), 2017.
   https://www.sciencedirect.com/science/article/pii/B9780323391542000059
   
2. Michael Allon, M.D., University of Alabama at Birmingham, Vascular Access for Hemodialysis, UCSF Department of surgery, 2014.
   https://surgery.ucsf.edu/conditions–procedures/vascular-access-for-hemodialysis.aspx

What is AV fistula?

Arterio-Venous fistula (AV Fistula) is a vascular connection created between an artery and a vein. This need to be done by a surgeon specialized in blood vessels (Vascular surgeon). Usually your surgeon would select vessels around the left wrist (on non-dominant hand).

Types of AV Fistula

Usually we create AV fistula for dialysis in two major sites.

• Wrist (Radio – Cephalic fistula)
• Elbow pit (Brachio – Cephalic fistula)

Radio – cephalic fistula

Radio cephalic fistula is the most difficult AV fistula to create. This is due to the small size of the radial artery and the cephalic vein around the wrist. Your vascular surgeon will stich the artery and veins to make the AV fistula for dialysis.

As a result of the Radio – Cephalic Fistula, there is a permanent connection between this two vessels. Therefore the high blood pressure of the radial artery cause high blood flow to the cephalic vein. So the cephalic vein get thicker.

Bachio – Cephalic fistula

When we need to create an AV fistula for the chronic dialysis, we often use vessels around the wrist. But as mentioned above it is not an easy surgery. In some patients distal AV fistula get failed. In such situations, we need to try for an AV fistula around the elbow fit.

Your vascular surgeon will connect the basilica artery in the medial side to the cephalic vein in the lateral side at the elbow pit. Then it create a vascular connection between these two arteries.

How to prepare for the AV fistula surgery?

Usually we create AV fistula for dialysis even before 6 months of 1st dialysis. Usually patient is counseled for the method of renal replacement therapy when he turns into the end stage kidney disease.

You will be referred to a specialized vascular surgeon for Av fistula creation.
When you meet your vascular surgeon, he will access some of your general conditions in addition to the vascular issues. This is for the preparation of the surgery.

Then he will perform a vascular mapping to select the best vascular access to create AV fistula for dialysis. As mentioned above, most preferred site of the surgery is the wrist. But if it is not well developed, He will select the Bachio – Cephalic access.

The AV fistula surgery is perform under general anesthesia. But in some stations they are doing it under local anesthesia or nerve block. This is often a day surgery.
After the surgery, your surgeon will review you for the maturation of the Av fistula around 3 months. Until that you need to have some exercise to improve the maturation of the AV fistula.

How to use AV Fistula for dialysis

When we discuss about the haemodialysis, the AV fistula is the most important part of the Haemodialysis procedure. Some says it is the lifeline of the CKD patients.

Assessment of the AV Fistula

The Arterio venous access should be properly maintained during dialysis. You need to continue adequate amount of wrist / arm exercises to improve the quality of AV Fistula.

Usually the vascular surgeon need to access the maturity and usability of the AV fistula for dialysis. If it is not adequately grown, you have to give some adequate exercise before the 1st puncture of the AV fistula site. In addition to the maturity there are some other factors to be assess by the vascular surgeon before allowing the usage of AV fistula for hemodialysis.

Puncturing of AV fistula for dialysis

After the proper assessment, a dialysis nurse or a dialysis technician will do the 1st puncture of your AV fistula for the initiation of the dialysis. The nurse will connect 2 AV fistula needles to your AV fistula site atleast 5 cm away from the surgical site. Usual gauge of the puncture needle for initial dialysis is 17G needles. One needle is inserted to the arterial side of the AV fistula. Then another needle is inserted to the venous side of the fistula.

The arterial needle will be used to drag blood from the body. Then the blood will be going through the dialysis machine. Then venous needle will be used to insert the cleared blood into body.
After the dialysis session, dialysis nurse will remove both needle with adequate pressure to avoid bleeding.

Your dialysis nurse will repeat this procedure in each dialysis session. However when your AV fistula is getting larger, you can select 16G AV fistula needle for the puncturing of AV fistula.

How to pain relive during fistula puncturing?

Each time when you are undergoing haemodialysis, you have to undergo repeated AV fistula site puncturing. Therefore you can use local anesthetic application or spray which include lignocaine like substance.

What are the advantages of AV fistula than other vascular access for dialysis patient?

AV fistula is the most effective vascular access. It has less complication during dialysis. Therefore it is often superior to all other methods like, AV graft, Permanent catheter or temporary catheter.
The benefit of AV fistula is followings;

1. Less chance to get clots.
2. Less risk of infections.
3. No autoimmune mechanisms as it use own vessels.
4. Can use as a permanent access as it serves longer than any of other forms.
5. Done as outpatient surgery.
6. Blood supply is very high.
   
   
   

What are the disadvantages of AV fistula for dialysis?

Even though AV fistula is superior to all other methods, still it has several disadvantages.

1. Take some time to mature. Therefore may have to use other temporary methods as vascular accesses.
2. This is a difficult surgery. We can’t perform it in some patients with small veins and arteries.
3. There are cosmetic issues.
4. Maturation need daily regular exercises.

Reference articles

1. Lee, C.; Toppin, J.; Snyman, A.; Oreopoulos, G.; Bhola, C.; Djaiani, G. Different anesthetic techniques for arteriovenous fistula formation: Early and late fistula failure rates, European Journal of Anaesthesiology: June 2011 – Volume 28 – Issue – p 121-122
   https://journals.lww.com/ejanaesthesiology/fulltext/2011/06001/different_anesthetic_techniques_for_arteriovenous.388.aspx
   
   
2. Increasing the Use of Arteriovenous Fistula in Hemodialysis: Economic Benefits and Economic BarriersDonald Schon, Steven W. Blume, Kimberly Niebauer, Christopher S. Hollenbeak, Gregory de LissovoyCJASN Mar 2007, 2 (2) 268-276. 
   DOI: 10.2215/CJN.01880606