NITROUS OXIDE

NITROUS OXIDE Anesthetic Colourless Odourless Non irritating Non Flammable Heavier than air LAUGHING GAS MINIMUM ALVEOLAR CONCENTRATION = 105% > Least potent 100% pure N2O cannot produce adequate anaesthesia Good analgesia Poor muscle relaxant Supplied in BLUE COLOURED STEEL CYLINDERS Low blood solubility Quick induction & Recovery SECOND GAS EFFECT........ DIFFUSION HYPOXIA ......... seen only with N2O used as a carrier of various anesthetics 75% N20 + 25-30% O2 + 0.2-2% Other anesthetic is employed for most surgical procedures ENTONOX ___50% N2O + 50% O2 Causes BONEMARROW SUPPRESSION & VITAMIN B12 DEFICIENCY N2O IS THE ONLY ANESTHETIC REPORTED TO CAUSE HEMATOLOGIC TOXICITY & NEUROTOXICITY WITH LONG TERM ADMINISTRATION Bone marrow supression can be prevented by prophylactic doses of FOLINIC ACID MEGALOBLASTIC ANEMIA & SUBACUTE COMBINED DEGENERATION OF CORD --------also occurs METHEMOGLOBINEMIA LARYNGOSPASM Contraindications : patients with PNEUMOTHORAX, PNEUMOPERITONIUM, VOLVULUS