Before an operation, a patient will meet with the anesthesiologist for an evaluation. The anesthesiologist will make a plan for the operation that takes into account the individual needs of the patient.
On the day of the operation, the anesthesiologist supervises the administration of medication so that the patient will not experience pain.
However, the anesthesiologist does not physically provide most anesthetics. They supervise either a CRNA or Anesthesia Assistant while they provide the anesthetic. CRNAs often work independently without supervision as well.