Hypokalemia, one of the most prevalent laboratory abnormalities in clinical practice, is defined as a potassium value of less than 3.6 mmol/L. Hypokalemia occurs in over 20% of hospitalized patients. It can be caused by the loss of total body potassium, usually from the gastrointestinal tract as a result of vomiting, diarrhea, or a surgical fistula, or from the kidney as a result of renal disease, diuretic administration, or increased aldosterone production. Hypokalemia can also develop as a result of a shift from extracellular fluid into cells, as seen in patients with alkalosis or with diabetes after the administration of insulin for hyperglycemia. Clinically, patients with mild hypokalemia may have no symptoms, but those with more profound hypokalemia can develop generalized weakness, tetany, and cardiac arrhythmias. In addition, hypokalemia may increase the toxicity of digoxin, whereas prolonged hypokalemia can cause secondary renal tubular damage, which may be permanent.
The treatment of hypokalemia consists of correcting the underlying disorder and replacing the potassium deficit. Oral replacement is preferred, but in patients with severe hypokalemia or when the oral route is not available, controlled intravenous infusion of potassium may be required. Commonly, if rapid replacement is required, intravenous potassium is administered as a series of mini-infusions of potassium chloride (KCl) solution, usually 10 mmol in 100 mL of IV fluid. viagra soft tabs online
Administration of concentrated solutions of KCl (>8 mmol/100 mL) through peripheral veins has been associated with pain at the infusion site. Studies show that lidocaine, either given as a bolus or added to the KCl infusion, can reduce this local pain significantly, although the routine use of a local anesthetic agent for this purpose is not generally recommended. There are also reports that infusions of 20 mmol of KCl in 100 mL normal saline or 40 mmol of KCl in 100 mL of 5% dextrose in water are well tolerated when given through a peripheral vein, with only occasional patient complaints of discomfort.
At Hamilton Health Sciences, intravenous KCl mini- infusions were traditionally prepared on the ward by nurses using concentrated KCl ampoules (2 mmol/mL) diluted with 0.9% sodium chloride (NaCl). These infusions were generally well tolerated. In an attempt to decrease the risk of serious or fatal medication errors attributable to the inadvertent administration of concentrated KCl injection, all injectable KCl ampoules (2 mmol/mL) were removed from ward stock in March 2000 and replaced with commercially prepared minibags of KCl (10 mmol in 100 mL sterile water) for the administration of intermittent KCl mini-infusions. Since this change of practice, nurses have reported numerous incidents of patients experiencing pain at the infusion site when the contents of these KCl minibags were administered with a peripheral venous cannula. Indeed, in a number of instances patients refused further doses because of the pain experienced during the first infusion. canadian cialis online
This randomized double-blind study tested the hypothesis that pain at the site of peripheral intravenous infusion is greater if KCL is administered in sterile water than if KCL is administered in saline.