Objectives: Phlebitis caused by peripherally infused potassium chloride (KCl) is well documented in the literature. This study focuses on documenting the rate, grade, and timing of this complication, and explores the cause and effect of added lidocaine on pain and phlebitis rate.
Methods: A retrospective chart review was conducted for patients receiving KCl peripheral infusion with or without added lidocaine. Descriptive statistical analysis was performed. The prevalence of infusion phlebitis was evaluated using the appropriate χ2 test, t-test/Mann-Whitney U test. A multivariate Cox proportional hazards regression model was used to assess the independent effect of age and sex on the rate of catheter-related complications. Statistical significance was considered at P < 0.05.
Results: There were 85 infusions of 10 and 20 mEq KCl, of which 67% (N = 57) had added lidocaine. Overall, phlebitis rate was 19%. There was less phlebitis with lidocaine-added infusions (13% vs 19%; P = 0.65), and infusions lasted more than those without added lidocaine. Animal and human data support the occurrence of a KCl-mediated vasoconstriction causing pain. Our data anecdotally support such observations. Besides the low pH and high osmolarity of KCl infusions, vasoconstriction seems to add insult to the patient veins. The role of lidocaine in alleviating pain and in delaying phlebitis may go beyond being a local anesthetic once its vasodilatory and anti-inflammatory effects are considered.
Conclusions: The cause of pain and phlebitis of KCl infusions may be more related to vasoconstriction than just low pH and high osmolarity. The addition of lidocaine to KCl infusions appears to be safe, and potentially delays or alleviates KCl infusion pain through its speculative vasodilatory and anti-inflammatory effects.