There are several disadvantages of disadvantages of carbon dioxide :
• High concentration causes narcosis.
• It increases the cerebral blood flow and intracranial pressure.
• It stimulates sympathetic nervous system, which may be dangerous in some patients already having systemic hypertension or myocardial ischaemia.
• It sensitizes myocardium to externally administered catecholamines.
• It reduces alveolar oxygen concentration.
• Nowadays it is proved to be more dangerous as compared to indications, so there is no provision for carbon dioxide cylinders in modem anaesthesia machines, because of the more proven disadvantages of carbon dioxide .