THE BODY UNDER GENERAL ANAESTHETIC

What happens to various parts of the body when we’re put under?

Brain activity

Electroencephalograms (EEGS) show that the electrical activity in the brain drops to a state deeper than sleep, mimicking a coma.

No snacking

General anaesthetics suppress the gag reflex and can cause vomiting, so to prevent choking patients must not eat before an operation.

Heart rate

The circulatory system is slowed by anaesthetic, so heart rate, blood pressure and blood oxygen are all continuously monitored.

Pain neurons

Unlike with local anaesthetics, pain neurons still fire under general anaesthesia, but the brain does not process the signals properly.

Muscle relaxation

A muscle relaxant is often administered with the anaesthetic; this causes paralysis and enables lower doses of anaesthetic to be used.

Memory

General anaesthetics affect the ability to form memories; the patient doesn’t remember the operation and often won’t recall coming to either.

Airway

Loss of consciousness and muscle relaxation suppress breathing and prevent coughing, so a tube and ventilator are used to maintain the airway.

Nausea

Many anaesthetics cause nausea. Often anti-emetic drugs that prevent vomiting are given after surgery.