NITROUS OXIDE AND OXYGEN FROM A SINGLE CYLINDER.
D000758:Anesthesia; D000773:Anesthesia, Obstetrical; D004864:Equipment and Supplies; D005260:Female; D006801:Humans; D008880:Midwifery; D009609:Nitrous Oxide; D009774:Obstetrics; D010100:Oxygen; D011247:Pregnancy
D009609:Nitrous Oxide; D010100:Oxygen
ANESTHESIA, OBSTETRICAL; EQUIPMENT AND SUPPLIES; MIDWIFERY; NITROUS OXIDE; OXYGEN; PREGNANCY