General anaesthesia

In modern medical practice, general anaesthesia is a complex procedure involving:

• preanaesthetic assessment
• administration of general anaesthetic drugs
• cardirespiratory monitoring
• analgesia
• airway management
• fluid management

Table of contents

1 Preaneasthetic evaluation 2 Monitoring 3 induction and maintenance of anaesthesia 4 Muscle relaxation 5 Airway management 6 External Links: 7 See also

Preaneasthetic evaluation

Monitoring

There are different guidelines concerning monitoring during anaesthesia, illustrated by the Australian and New Zealand College of Anaesthetists recommendations:

1. Continuous electrocardiography (ECG) - placement of electrodes which monitor heart rate and rhythm, as well as showing evidence of other cardiac pathologies (e.g. ischaemic heart disease).

2. Continuous pulse oximetry (SpO2) - Allows early detection of cyanosis and a fall in patients' blood oxygen tension.

3. Blood pressure Monitoring (NIBP or IBP) - Generally non-invasive methods of measuring blood pressure such as a dinamap(TM) or machine which continuously checks blood pressure non-invasively. Alternatively, for major surgery such as cardiac surgery, anaethetists may use invasive monitoring with an arterial cannula.

4. Agent concentration measurement - Common anaesthetic machines have meters to measure the percent of inhalational anaesthetic agent used (e.g. sevoflurane, isoflurane, desflurane, halothane etc).

5. Low oxygen alarm - Almost all circuits have a backup alarm in case the oxygen delivery to the patient becomes compromised. This warns if the fraction of inspired oxygen drops lower than room air (21%) and allows the anaethetist to take immediate remedial action.

6. Circuit disconnect alarm - indicates failure of circuit to achieve a given pressure during mechanical ventilation.

7. Carbon dioxide measurement (capnography)

induction and maintenance of anaesthesia

Muscle relaxation

Airway management

External Links:

See also

• • Intraoperative awareness