Serum lidocaine concentrations following subcutaneous administration

Area of Science:

• Emergency Medicine
• Pharmacology
• Anesthesiology

Background:

• Lidocaine is commonly used for local anesthesia in emergency settings.
• Subcutaneous administration is a frequent route for managing lacerations.
• Understanding lidocaine absorption is crucial for patient safety and efficacy.

Purpose of the Study:

• To determine serum lidocaine concentrations after subcutaneous administration for laceration management.
• To investigate potential systemic absorption of lidocaine in the emergency room setting.
• To assess the impact of traumatized tissue on lidocaine absorption.

Main Methods:

• Thirty patients received subcutaneous lidocaine hydrochloride 1% (10-300 mg) for laceration repair.
• Venous blood samples were collected at 15, 30, 45, and 60 minutes post-administration.
• Serum lidocaine levels were measured using immunoassay and confirmed by gas chromatography.

Main Results:

• No detectable serum lidocaine concentrations were found in any patient samples.
• No evidence of lidocaine absorption from the subcutaneous injection sites was observed.
• These findings suggest altered absorption characteristics in traumatized tissue.

Conclusions:

• Subcutaneous lidocaine administration for laceration management in the emergency room did not result in detectable systemic absorption.
• Traumatized tissue may significantly alter the absorption profile of subcutaneously administered lidocaine.
• Further research is warranted to elucidate the mechanisms behind altered lidocaine absorption in injured tissues.