Inclusion Criteria:  indication requiring anesthesia maintenance; patient's written consent about the type of anesthesia and possible complications of regional anesthesia  Exclusion Criteria:  patient's refusal of application for the proposed form of anesthesia; patients younger than 18 years; patients weighing less than 50 kg; a physical status score of more than 3 determined by the American Society of --Anesthesiologists (ASA); a history of allergic reactions to the drugs used; coagulopathies; infections of the skin at the injection site; neurological or neuromuscular diseases; severe liver diseases or kidney failures; an inability to cooperate with the patient.