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 1st 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.
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