Differences between local anesthesia, sedation,
monitored anesthesia care (MAC) and general anesthesia

Local anesthesia

In general, local anesthesia is the external application or injection of medication to the specific part of the body to induce the absence of sensation. Commonly used medications in local anesthesia include xylocaine and lignocaine. Patient remains conscious throughout the procedure.


Medications will be injected intravenously by doctors. Patient will fall asleep after the injection, so as to minimize the discomfort during examination. Common sedations include midazolam and pethidine.

Monitored anesthesia care (MAC)

Strictly speaking, MAC is also a kind of sedation, but provided by anesthetist. The medication and its dosage will be controlled by the anesthetist, and the drug will also be injected intravenously. Commonly used medication include propofol and fentanyl.

General anesthesia

Patients will be unconscious after the injection or inhalation of medication . Airway will be protected during the procedure, such as intubation. Most of the general anesthesia requires hospital setting.

Follow up after the examination

Local anesthesiaSedationMACGeneral anesthesia
General comfort*************
ProsFully awake during the procedureMinimal discomfort in most circumstances No discomfortFor high risk procedure
ConsDiscomfort Longer recoveryQuick recoveryRequired hospital setting

Sedation is suitable for most patients in general. For more comfort, some patients may choose MAC. Patients with the following conditions may consider MAC as their first choice:

  • alcoholism

  • chronic illnesses (such as cardiac/ pulmonary diseases, diabetes, hypertension)

  • advanced age (>70)

  • obesity

  • sleep apnea

  • on long term psychiatric medication or hypnotics