This study showed that peripheral intravenous KCl infusion caused significantly more pain at the infusion site when administered in sterile water than in saline. The exact mechanism of infusion-related pain and phlebitis is not known. Irritation, inflammation, and damage to the venous endothelium can be caused by the inherent chemical property, pH, or osmolality of the infusate.
In the current study, the concentrations of KCl and pH were the same in all 3 groups of solutions. The greater pain experienced with infusions of KCl in sterile water could be due to the difference in the osmolality of the final solutions of KCl because of its dilution with different IV fluids. The effect of infusate osmolality on infusion pain is not a well-researched phenomenon,although the incidence of phlebitis after infusions of hypertonic solutions with osmolalities higher than 600 mmol/kg has been reported for solutions of parenteral nutrition amino acids and with some anesthetic agents. The osmolality of body fluids is close to 285 mmol/kg.2 Little has been reported on the effect of hypotonic solutions, except the well-known fact that a solution of 0.4% NaCl, which has an osmolality of about 130 mmol/kg, causes hemolysis. The data from the current study suggested that a hypotonic solution (10 mmol KCL in sterile water, osmolality 170 mmol/kg) is more irritating than a hypertonic solution (10 mmol KCL in 0.9% NaCl, osmolality 438 mmol/kg) when administered through a peripheral vein. However, the range of osmolalities studied was too small to allow any definitive conclusions to be drawn.
Other limitations of this study were the small number of patients and other risk factors not taken into account, such as the cannula used, the anatomical location of the cannula, and the duration of cannulation, which also affect pain at the infusion site. revatio 20 mg
Given that hypokalemia is a common occurrence in hospitalized patients and that severe hypokalemia can be life-threatening, it is important that intravenous potassium replacement be carried out with a minimal chance of infusion failure caused by phlebitis, extravasation, or patient refusal because of intolerability. It is also of paramount importance that patients’ discomfort be kept to a minimum. This study demonstrated that a KCl solution administered as a mini-infusion through a peripheral vein should not be diluted with sterile water for injection.