What are the effects of depositing local anesthetic at 1 ml/min?

What are the effects of depositing local anesthetic at 1 ml/min?

• A. No adverse effects
• B. Increased adverse effects
• C. Painful injection
• D. Faster onset

Answer: (A)

Slow, controlled deposition of local anesthetic minimizes rapid systemic uptake. When you deliver the solution at about 1 ml per minute, it enters tissues gradually, so peak blood levels stay low and the likelihood of systemic toxicity—along with related adverse effects—decreases. This slow rate also reduces the amount of tissue distension and pressure from the injection, which can lessen discomfort from the injection itself. The onset of anesthesia is driven more by the drug’s diffusion to the target nerve and the site of injection (and whether a vasoconstrictor is used) than by simply the speed of deposition, so you wouldn’t expect a faster onset from this rate. In essence, this slow deposition rate is associated with minimized adverse effects, making no adverse effects the best-supported outcome. Minor injection-site discomfort can still occur due to needle penetration, but systemic or serious adverse effects are unlikely at this controlled rate.

Slow, controlled deposition of local anesthetic minimizes rapid systemic uptake. When you deliver the solution at about 1 ml per minute, it enters tissues gradually, so peak blood levels stay low and the likelihood of systemic toxicity—along with related adverse effects—decreases. This slow rate also reduces the amount of tissue distension and pressure from the injection, which can lessen discomfort from the injection itself. The onset of anesthesia is driven more by the drug’s diffusion to the target nerve and the site of injection (and whether a vasoconstrictor is used) than by simply the speed of deposition, so you wouldn’t expect a faster onset from this rate. In essence, this slow deposition rate is associated with minimized adverse effects, making no adverse effects the best-supported outcome. Minor injection-site discomfort can still occur due to needle penetration, but systemic or serious adverse effects are unlikely at this controlled rate.