Medical Gases
2
We breathe earth’s atmosphere composed of:
– Nitrogen (78%) – Oxygen (21%)
– Carbon Dioxide (0.03%)
– Argon and trace gases (0.93%)
• Neon, Xenon, Krypton and Deon
Respiration
Of all the uses of oxygen, sustaining life is the most important. Oxygen is needed by
all living organisms. Through a process known as aerobic respiration, energy from
food is generated. This allows humans and animals to perform their daily activities.
at high concentration in acute or severe asthma or lung diseases such as pulmonary thrombo- embolism (a blockage of one of the arteries in the lung), pneumonia fibrosing alveolistis
(inflammation and scarring of the air sacs of the lungs) and pulmonary edema
in low concentrations when there are breathing difficulties due to conditions such as chronic obstructive airways disease
in the treatment of acute and severe asthma, sleep apnoea, cluster headache, shock and in other situations where localised blood supply is poor.
when the oxygen capability of the blood is reduced such as in carbon monoxide poisoning or severe anaemia
when gas is trapped in body spaces such as in pneumothorax (air that is trapped next to a lung resulting in collapse of the lung) or air embolism or other gas disturbances such as decompression sickness (associated with diving)
as a carrier gas or as a diluent for anaesthetic gases or vapours.
In cryopreservation for the long-term preservation of blood, blood components, other cells, body fluids or tissue samples.
In cryosurgery for minor surgical procedures in dermatology.
As a component in many gas mixtures.
As a displacement medium for sterile equipment, a non-oxidising displacement medium
in pharmaceutical vials and as a propellant in pressurised aerosol dispensers.
As a source of pneumatic pressure to power gas-operated medical devices.
As a coolant for carbon dioxide surgical lasers.
It can also be used as part of the medical gas mixture for lung function tests.
The pharmaceutical industry uses this medical gas in the manufacture of medications.
Nitrog
en
• to increase depth of anaesthesia rapidly when volatile agents are being administered. It increases depth of respiration and helps to overcome breathholding and bronchial spasm
• to facilitate blind intubation in anaesthetic practice
• to facilitate vasodilation and thus lessen the degree of metabolic acidosis during the induction of hypothermia
• to increase cerebral blood flow in arteriosclerotic patients undergoing surgery
• to stimulate respiration after a period of 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
• as solid carbon dioxide (dry ice) in tissue freezing techniques and for the destruction of warts by freezing
Carbon dioxide
Laughing gas or happy gas
when an inhalation anaesthetic is required, the administration of nitrous oxide is usually
accompanied by simultaneous administration of a volatile agent such as halothane, ethrane, etc.
in the relief of severe pain, usually in emergency situations, by inhalation with 50%
oxygen
in short-term procedures which inevitably involve pain, such as wound and burn dressing,
wound debridement and suturing. Administrated usually with 50% oxygen
in dental work to provide short-term analgesia for tooth extraction and other brief procedures, administered with 50% oxygen
occasionally as an insufflating agent in laparoscopy
in cryosurgery as a refrigerant.
Nitrous oxide
Helium can be used for breathing observation.
It is essential in treating ailments asthma, emphysema and other conditions that affect breathing.
The gas is usually used to treat diseases that affect the lungs.
Hospital MRI scans relies on liquefied helium.
Acute and chronic forms of respiratory ailment treatments have helium components. In almost all cases, oxygen and helium are used together. This combination gets to the lungs much quicker.
Helium in different forms and combinations are used in medical instrumentations and nuclear medicine.
