Droperidol: A butyrophenone with general properties similar to those of HALOPERIDOL. It is used in conjunction with an opioid analgesic such as FENTANYL to maintain the patient in a calm state of neuroleptanalgesia with indifference to surroundings but still able to cooperate with the surgeon. It is also used as a premedicant, as an antiemetic, and for the control of agitation in acute psychoses. (From Martindale, The Extra Pharmacopoeia, 29th ed, p593)Antiemetics: Drugs used to prevent NAUSEA or VOMITING.Postoperative Nausea and Vomiting: Emesis and queasiness occurring after anesthesia.Ondansetron: A competitive serotonin type 3 receptor antagonist. It is effective in the treatment of nausea and vomiting caused by cytotoxic chemotherapy drugs, including cisplatin, and has reported anxiolytic and neuroleptic properties.Neuroleptanalgesia: A form of analgesia accompanied by general quiescence and psychic indifference to environmental stimuli, without loss of consciousness, and produced by the combined administration of a major tranquilizer (neuroleptic) and a narcotic.Adjuvants, Anesthesia: Agents that are administered in association with anesthetics to increase effectiveness, improve delivery, or decrease required dosage.Metoclopramide: A dopamine D2 antagonist that is used as an antiemetic.Vomiting: The forcible expulsion of the contents of the STOMACH through the MOUTH.Promethazine: A phenothiazine derivative with histamine H1-blocking, antimuscarinic, and sedative properties. It is used as an antiallergic, in pruritus, for motion sickness and sedation, and also in animals.Ambulatory Surgical Procedures: Surgery performed on an outpatient basis. It may be hospital-based or performed in an office or surgicenter.Preanesthetic Medication: Drugs administered before an anesthetic to decrease a patient's anxiety and control the effects of that anesthetic.