Sometimes anaesthesia will need to be given to patients away from the usual hospital environment. This means there will be differences in several key areas:

• isolation – an appropriate level of experience in airway management and anaesthesia is essential as back up might be a long way away, or not available at all;
• the safety of the environment – uneven ground, water hazards, roads/traffic;
• extremes of weather conditions;
• lighting;
• resources available, in terms of equipment, drugs, monitoring, power sources, assistants;
• number of staff;
• the type of patient and their injuries;
• lack or absence of investigations, e.g. X rays, lab tests;
• postoperative recovery facilities.

Examples of locations include isolated clinics, road or rail traffic accidents, and military engagements. Administration of anaesthesia in isolated sites is becoming less common.

It is essential that the same standard of monitoring, equipment and recovery facilities are available as there are in a hospital setting.

Although now less commonly used, portable vaporizers are available for use in an isolated situation. Inhalational anaesthesia can be given using a drawover vaporizer to provide anaesthesia in remote locations. It functions by using air, with or without supplemental oxygen, being drawn over a vaporizer and from there to the patient. The patient’s own respiratory effort or a self-inflating bag drives the system. Desirable features include having low internal resistance to gas flow and the ability to deliver a constant concentration of volatile anaesthetic despite changes in the patient’s minute volume or the operating temperature. It has the advantages of being: portable, cheap and simple design, no need for pressurized fresh gas flow and robust.

Trauma

The important factors in a trauma situation include:

• safety of rescuers;
• stabilization of patient (ABC and primary survey; see Chapter 25);
• transport;
• definitive treatment.

The ‘golden hour’ is a term used to emphasizes the />