Modern anaesthetic machines have improved greatly since 1917 when Boyle modified the American Gwathmey apparatus of 1912 to develop the ubiquitous continuous flow anaesthetic machine. Despite this, the basic principles and many components remain, albeit in modernized form. Gas is still supplied to the machine from a high-pressure source which is stepped down to a safe pressure supplying the breathing system. Flowmeters control gas flow and allow for adjustment of different inspired concentrations of gases. A vaporizer adds anaesthetic vapour to the inspired gas which is then delivered to the patient via a dedicated breathing system. But modern improvements in safety, requirements for increased monitoring and improved technology have driven change in the anaesthetic machine. Modern anaesthetic workstations employ digital technology to deliver safe and measured anaesthesia to patients. Despite improvements in safety and reliability, routine checking of anaesthetic machines before use is essential. The Association of Anaesthetists of Great Britain and Ireland (AAGBI) have developed a standardized checklist for users to ensure all components of the anaesthetic machine are functioning appropriately.
- Adjustable pressure limiting valve
- anaesthetic machine
- Bodock seal
- hypoxic guard
- non-interchangeable screw thread