To start dialysis in chronic kidney disease patients, many subjective and objective criteria should be considered by the patient and his clinician

INDICATIONS FOR DIALYSIS INITIATION IN CHRONIC KIDNEY DISEASE

 

 

To start dialysis (DX) in chronic kidney disease (CKD) patients, many subjective and objective criteria should be considered by both the patient and his/her clinician. This decision cannot be established via an absolute laboratory figure by which an indication for dialysis is urgently required. Many factors have been involved such as how the patient perceive this decision and the magnitude of the associated anxiety about commencing a complicated, potentially life-long approach therapy. Furthermore, the physician’s interpretation about the patient’s current health condition, renal function deterioration, and the expected adverse effects of this approach of therapy may guide the suggested time of commencing RRT (renal replacement therapy). To summarize, the decision of when to commence DX is obviously one of the most serious decisions that both the patient and his clinician have been implicated.

 

INDICATIONS 

Clinical indications that invite the need to start DX in a CKD patient may include:

1)    Pericarditis (inflammation of the heart pericardium) or pleuritis (inflammation of the lung pleura) (urgently indicated)

2)    Neurological complications e.g. advanced uremic encephalopathy or neuropathy, associated with certain signs e.g. confusion, tremors, dropped wrist/foot, or, in advanced cases, presence of convulsions (urgent indication)

3)    Clinically significant bleeding tendency related to uremia (urgently indicated)

4)    Permanent metabolic alterations that’re resistant to medical treatment; including hyperkalemia, metabolic acidosis, hypercalcemia, hypocalcemia, and hyperphosphatemia

5)    Fluid overload that’s resistant to diuretic therapy.

6)    High blood pressure (BP) with poor response to antihypertensive drugs.

7)    Resistant nausea and vomiting to medical therapy.

8)    Current criteria of malnutrition

The 1^st 5 of this list are potentially life-threatening and must not be allowed to appear before DX institution in CKD patients under nephrology supervision. The last 2 manifestations may appear slowly and can be attributed to other co-morbidities or due to medications-associated adverse effects. They cannot be considered less serious.

 

 

Relative indications 

Considering that DX is to improve patient’s quality of life and extend his survival, it is crucial to consider the less severe indications for DX. Examples may include anorexia (loss of appetite) and nausea, deteriorated nutritional states, sleeping tendency, and lowered energy, and cognitive alterations. However, evaluation of these signs/symptoms is variable in cases with slowly progressive kidney diseases. A given explanation for this variability may include:

v  The ability of some patients to tolerate these symptoms associated with the subjective sense of denial as long as kidney failure proceeded.

v  Many of these symptoms may be attributed to the adverse effects related to the current medications, such as nausea and gastric upsets associated with oral iron preparations.

Location of dialysis

v  The procedures of dialysis can be performed in a near hospital, in a specified centre for dialysis or it can be commenced at home. A deep discussion between the patient and his clinician in regard the patient’s current clinical status and the available therapeutic options should be instituted.

Types of dialysis

v  Two types of dialysis are currently available, hemodialysis and peritoneal one. Again, a full detailed discussion between the patient and his nephrologist in regard the patient’s wishes and the current therapeutic options must be undergone.

What is hemodialysis

v  In hemodialysis modality, an artificial kidney mimicking-within limits- the function of the native kidney and is called the “hemodialyzer” is usually utilized as a tool for removing uremic toxins as well as extra fluid from patient’s blood. To allow patient’s blood to reach the dialyzer, it is necessary to perform an access (vascular access) surgically to provide an enough amount of blood to be dialyzed (cleaned). This access is usually made in patient’s arm or on his/her leg (femoral site). A synthetic catheter can be placed in a suitable vein for dialysis, but a vascular surgeon may create a connection between an artery and a near vein that make the latter bigger and wider (fistula) to supply a suitable amount for hemodialysis.

v  The creation of the arterial/venous connection (fistula) may not be always feasible. A synthetic plastic tube (the graft) can be created instead for the purpose of vessel connection. However, if these trials were not feasible, another plastic tube (the catheter) may be placed on a large vein, either in the neck base or in the large vein of the thigh (femoral vein).  Moreover, a more “permeant catheter” cab be utilized for a longer period through a “knob” attached permanently under the skin and called “Permcath”.

 

Nutritional status

Patients maintained on regular dialysis are vulnerable for a higher risk of mortality if they are evidently malnourished. Plasma albumin, for example, is inversely related to the MR (mortality rate). A given level of less than (35-40 g/L) has been related to a higher mortality. A more upgrading of this relation is to relate plasma albumin at the timing of DX start to patient’s survival. Patients with hypoalbuminemia at DX initiation are vulnerable to a higher risk of mortality as compared to those with normal levels. Moreover, this role can be also applied to diabetics with proteinuria and hypoalbuminemia. The same interpretations can be considered with patients on peritoneal dialysis (PD).

In the “nephrotic syndrome” (except for DM) and ESRF, the associated hypoalbuminemia is of unsettled significance, where hypoalbuminemia in these patients may not reflecting malnutrition, but denotes an underlying inflammatory process or continuous urine loss of proteins.

In addition to reflecting kidney function, serum creatinine (S. Cr) is also reflecting the magnitude of muscle mass. To conclude: in a patient with a low S. Cr value and needs DX due to uremic manifestations, this means an associated muscle mass reduction. In this concept, current data denotes that late mortalities may be greater with a S Cr vales of less than 10 mg/dL (884 µmol/L) at DX initiation. On the other hand, BUN readings has no similar significance.

So, the finding of lowered plasma albumin associated with gastrointestinal symptoms such as anorexia, nausea and vomiting at the start of dialysis are considered of crucial prognostic signals. In addition, plasma transferrin, somatomedin C, pre-albumin, and total cholesterol may have the same role.

To simplify an access for nutritional status evaluation, patient daily protein consumption can be considered. On the other hand, CKD patients with no dietary restriction should limit their protein intake to delay their progress in a failing kidney.

Dietary Guidelines for Adults commencing Hemodialysis

With the start of hemodialysis, certain alteration should be considered the daily routine including the daily diet. The following concepts have to be considered:

1)    The optimum kind as well as the optimum amount of food.

2)    Compliance with the medications prescribed by the responsible physician is mandatory.

3)    Compliance with the dialysis schedule is crucial to achieve an adequate dialysis.

In regard to the diet of the dialysis patient, the following general instruction may be considered and followed by a kidney dietician:

1)    More rich protein diet is essential.

2)    Consume less salt, potassium, and phosphorus-rich diets.

3)    Adjust your fluid intake including plain water, tea, coffee and other juices.

Effect of dialysis 

Despite the associated improvement in patient’s appetite with the start of dialysis, there is no strong evidence suggesting that this means an improvement of the patient’s nutritional status.

DOES EARLY DIALYSIS OR REFERRAL IMPROVE SURVIVAL/OUTCOMES?

Survival and dialysis complications

The impact of early dialysis on patient’s outcome still uncertain. However, as kidney function decline progressed, immediate referral to the nephrologist as well as the proper preparation for either dialysis or a kidney transplant should be instituted. Both the patient and his/her nephrologist should be alert to appearance of the uremic manifestations with immediate contact to the nearest dialysis center. Decision of dialysis institution is better commenced via a combination of the presence of clinical indications in addition to an estimation of the proper GFR value.

 

STAGES OF CHRONIC KIDNEY DISEASE

There is no absolute figure (in GFR) below which immediate dialysis should be indicated. However, to guard against the potential life-threatening adverse effects of the uremic toxins, DX should be planned in any asymptomatic patient with a very low level of the GFR e.g.  eGFR of about 8-10 mL/min per 1.73 m² body surface area. Nevertheless, some nephrologists may prefer a very close monitoring to an asymptomatic patient with advanced CKD with commencement of DX once the patient is symptomatizing.

However, most CKD patients usually start dialysis owing to the evolution of uremic toxemia at the level of 10 mL/min per 1.73 m² or little above. At any approach, if dialysis was not initiated urgently with a deteriorated GFR, an access for dialysis should be currently provided. As a role for all patients, vascular access should be considered before dialysis is currently indicated

Furthermore, two more benefits of early dialysis could be provided, management of hypertension as well as more liberty in dietary intake. As the developed hypertension is usually volume-dependent, ultrafiltration (volume deloading or removal of excess water) undergone during dialysis has a direct impact on blood pressure lowering. Of more significance, dialysis patients may require 1-1.2 g/kg body weight per day to cope with their protein losses during dialysis and preserve their nitrogen balance. Consequently, an early start of dialysis may permit a more liberty in food in fluid consumption. In contrary, dialysis delay may allow more time for the vascular access maturation and also for enrollment on a kidney transplant list.

 

Peritoneal dialysis (PD)

 Commencing PD may be associated with a unique set of challenges in regard to the timing of DX start. Whilst HDX vascular access is better performed weeks to months before DX initiation, the PD catheterization is generally created only 10-14 d before utilization. Patients on PD must have adequate training to start DX, that’s may be difficult to be performed in a symptomatizing uremic cases. Among patients requiring acute start of chronic DX, HDX module is better commenced first, even if PD is the modality of choice on the long run.

Consequently, the proper timing of PD start may be a more complicated concept that necessitate close collaboration between the nephrologist, patient and his/her family, and DX center which’s responsible of patient’s preparation.

 

Possible value of early referral

One of the common and serious problems in the field of nephrology is the “late referral” of a CKD patient to his/her nephrologist. Referral is currently observed in a different levels of kidney function, but it is more commonly seen in a late stages of the disease, usually with a uremic patient suffering from its manifestations or a little earlier. The late referral may partially reflect the absence of direct need for dialysis in some patients despite an associated decline in kidney function. On the other hand, the “early referral” may offer many advantages such as:

1)    To recognize the magnitude of kidney disease progression,

2)    To identify any reversible (correctable) causes of kidney function deterioration,

3)    Close monitoring to the patient and DX planning in its proper timing.

4)    Net result would be an improvement of the patient survival.

Avoiding the emergent start of dialysis

It has been observed that postponing dialysis for a too prolonged time for any reasons, may be associated with need for hospital admission for urgently required dialysis. This finding may lead the physician to address an early scheduled program for dialysis to avoid the hazards of emergent dialysis.

INITIATION OF DIALYSIS AND DIALYSIS DISEQUILIBRIUM  

The patients who initiate dialysis with several uremic manifestations, may be amenable of serious complication if they commence an intense dialytic process, that is the “disequilibrium syndrome”. This syndrome may be induced due to the rapid removal of uremic toxins with resultant fast reduction in plasma osmolality. Several manifestations can be induced such as headache, nausea, recurrent vomiting, blurred vision, muscle twitches, disorientation, tremors, and convulsions. seizures. The risk of this syndrome may be currently enhanced with the presence of underlying neurological disorders of a severely azotemic patients.

N.B. This Blogger is created to inform the CKD patient when to start dialysis therapy.