It is liquifiable under pressure, with refrigerant properties in the liquid phase and is supplied in cylinders as a liquid under its own vapour pressure of approximately 5,000 kPa at 15°C.
DE and EE cylinders are fitted with an eductor tube to allow liquid withdrawal. Carbon Dioxide will cause asphyxiation, is inert and mildly toxic. As it is much heavier than air it will collect in ducts, drains and low lying areas.
Uses of Medical Gases - Carbon Dioxide:
Medical applications for Carbon Dioxide include its use as a pure gas or in specialised mixtures with other gases in stimulation of breathing and anaesthesia. In liquid form Carbon Dioxide is used in cryosurgery for freezing tissue.
Carbon Dioxide is an essential constituent of tissue fluids and is needed to supplement various anaesthetic and oxygenation mixtures under special circumstances such as cardiopulmonary bypass surgery and the management of renal dialysis.
It also has a limited place as a respiratory stimulant and is used in the investigation and assessment of chronic respiratory disease.
Medical Carbon Dioxide is used:
- To rapidly increase depth of anaesthesia when volatile agents are being administered. It increases the depth of respiration and helps to overcome breath-holding and bronchial spasm
- To facilitate blind intubation in anaesthetic practice
- To facilitate vasodilatation, lessening the degree of metabolic acidosis during the induction of hypothermia
- To increase cerebral blood flow in arteriosclerotic patients undergoing surgery
- To stimulate respiration after apnoea
- In chronic respiratory obstruction after it has been relieved
- To prevent hypocapnia during hyperventilation
- For clinical and physiological investigations
- In gynaecological investigation for insufflation into fallopian tubes and abdominal cavities