definition, causes ,clinical features, diagnostic evaluation, treatment

2.  Hyperkalemia (greater-than-normal serum potassium
concentration)
 seldom occurs in patients with normal renal function. Like
 hypokalemia, hyperkalemia is often due to iatrogenic
(treatmentinduced)
 causes. Although less common than hypokalemia,
hyperkalemia
 is usually more dangerous because cardiac arrest is more
 frequently associated with high serum potassium levels.

3.  Clinical Manifestations
 The most important consequence of hyperkalemia is its effect
on
 the myocardium. Cardiac effects of an elevated serum
potassium
 level are usually not significant below a concentration of 7
mEq/L
 (7 mmol/L), but they are almost always present when the
level is
 8 mEq/L (8 mmol/L) or greater. As the plasma potassium level
rises,
 disturbances in cardiac conduction occur.

4.  Assessment and Diagnostic Findings
 Serum potassium levels and ECG changes are crucial to the
diagnosis
 of hyperkalemia, as discussed above. Arterial blood gas
analysis
 may reveal metabolic acidosis; in many cases, hyperkalemia
 occurs with acidosis.

5.  An immediate ECG should be obtained to detect changes.
 restriction of dietary potassium and potassium-containing
medications.

6.  When serum potassium levels are elevated, necessary to
administer IV calcium gluconate.
 Within minutes after administration, calcium antagonizes the
action of hyperkalemia on the heart.
 Infusion of calcium does not reduce the serum potassium
concentration but immediately antagonizes the adverse
cardiac conduction abnormalities.

7.  Monitoring the blood pressure is essential to detect
hypotension,which may result from the rapid IV
administration of calcium gluconate.
 The ECG should be continuously monitored during
administration;
 the appearance of bradycardia is an indication to stop the
infusion.

8.  IV administration of sodium bicarbonate may be necessary to
alkalinize the plasma and cause a temporary shift of
potassium into the cells.

9.  IV administration of regular insulin and a hypertonic dextrose
 solution causes a temporary shift of potassium into the cells.

10.  Actual removal of potassium from the body is required; this
may be accomplished by
 peritoneal dialysis,
 hemodialysis or
 other forms of renal replacement therapy.

11.  Patients at risk for potassium excess, for example those with
renal
 failure, should be identified so they can be monitored closely
for
 signs of hyperkalemia.

12.  The nurse observes for signs of muscle
 weakness and dysrhythmias. The presence of paresthesias is
noted,
 as are GI symptoms such as nausea and intestinal colic. For
patients
 at risk, serum potassium levels are measured periodically.