Provision of anaesthesia in difficult situations and the developing world

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Chapter 27 Provision of anaesthesia in difficult situations and the developing world

The provision of anaesthesia in modern well-equipped operating theatres is dependent on sophisticated electronic equipment that requires an uninterrupted supply of both electricity and compressed gasses. Such equipment is not readily transportable, although it may be moved within a hospital facility. There are many locations throughout the world where anaesthesia is administered to facilitate surgery, investigations or other forms of treatment outside this generally accepted ‘safe’ environment.

The following are examples of locations and situations away from hospital operating theatres where anaesthesia may be required, and where simpler or alternative means of providing anaesthesia may need to be employed:

Domiciliary anaesthesia – as in kitchen table appendicectomy and obstetric flying squad interventions – has long been abandoned on safety grounds and, more recently, so has anaesthesia in dental surgeries in the UK.

All of these situations are remote from the relatively safe, comfortable and familiar operating theatre anaesthetic environment, and the following problems may be encountered to a greater or lesser degree:

Where possible, on grounds of safety, patients should be transferred to medical facilities capable of providing the appropriate level of care. For example, electroconvulsive therapy for the psychiatric patient with severe aortic stenosis and depression would be better managed (from their cardiac status) in the operating suite of the main hospital rather than in a room off the psychiatric ward. Non-essential surgery should not be undertaken at the site of a major disaster or on the battlefield, and the use of local, regional or sedative techniques should be considered where appropriate.

The overriding principle in providing anaesthesia under any of these conditions should be to use a simple, safe technique familiar to the practitioner. To reduce complexity and avoid the potential administration of a hypoxic gas mixture as well as reducing the need for scavenging (and for many other well-documented reasons), there is a case for avoiding the use of nitrous oxide entirely. Training and practice in such techniques is invaluable for the time when they may be required. Even within a modern operating theatre environment, a ‘difficult situation’ may arise due to failure of a sophisticated electronic anaesthetic workstation, a major power cut with failure of back-up generators or a disruption to piped gas supply. The use of total intravenous anaesthesia (TIVA) together with a self-inflating bag and a free-standing oxygen cylinder, combined with practical clinical monitoring, will allow adequate and safe anaesthesia in such a situation. Under such circumstances a hands-free torch or headlight may be the most essential item of additional equipment.

Difficult situations within hospitals

Sites away from the operating theatres often have anaesthetic equipment that is used only occasionally. Piped oxygen and suction facilities may be absent. The equipment in such areas must be maintained and checked adequately, with basic monitoring meeting the standard recommended by the Association of Anaesthetists.1 Since January 2003, all anaesthetic machines in use in the UK must be incapable of delivering a hypoxic mixture. There must be immediate access to resuscitation equipment and drugs, and a means of summoning additional assistance (i.e. telephone or intercom). The anaesthetist and their assistant should have sufficient experience and be familiar with both the environment and the equipment.

Some specific problems with regard to patients, medical attendants and equipment within particular areas are listed below.

Remote anaesthesia

Anaesthesia for MRI, radiotherapy and some radiological procedures may necessitate the anaesthetist and the bulk of the anaesthetic equipment being remote from the patient. This may be either to ensure all ferromagnetic equipment is outside the magnetic field, or to remove anaesthetic personnel from ionizing radiation:

• TIVA may be employed using long infusion lines on pumps which must be able to cope with the high resistance to flow caused by the increased length. This usually means setting to maximum the pressure limit for sensing an occlusion.

• Whilst sedation may be sufficient for some patients, the airway may need to be established with a supraglottic airway device or tracheal tube.

• Intermittent positive pressure ventilation through a long coaxial breathing system such as a 9.6–10 m Bain circuit and Nuffield Penlon series 200 ventilator, has been shown to provide safe anaesthesia.3 With this system, there is an increase in the static compliance in proportion to the length of the tubing. This is caused by expansion of the breathing hose and compression of the volume of gas during positive pressure ventilation and will result in a lower tidal volume being delivered than is set on the ventilator although this may be mitigated by the tidal volume supplementation from the fresh gas flow. Capnography is essential. In children, if a Newton valve is used, the ventilator becomes a pressure generator, and the increased resistance and compliance of the long system results in the pressure delivered being significantly less than that selected (23% less with a 10 kg child). This compares to a 6–11% reduction when using a long rubber Ayre’s T-piece.4

• The capnography signal is delayed due to the length of the sampling line but provides a guide for adjustment of the tidal volume.

Interhospital transfers

It is sometimes necessary to transfer anaesthetized patients to another hospital, particularly if they require specialist services which are not available on site. Often these patients will be critically ill and the keys to their successful transfer are communication, documentation and anticipation of possible problems. All hospitals should have a checklist for interhospital transfers:

Developing countries

There are two extremes of conditions that may be met in providing anaesthesia in developing countries. The anaesthetist may be totally dependent on the equipment, drugs and personnel provided within the healthcare system of that country, or they may be part of a visiting team that is totally self-contained. Visiting teams may be very operation specific (e.g. Project Orbis, Operation Smile and other eye or cleft palate teams), or they may have a much wider remit. Operation specific teams usually have rigid pre-assessment protocols, ensuring that standardized procedures are carried out on fit patients, enabling the greatest good to be done for the largest number of people. Some visiting teams may bring all facilities needed to perform a certain number of specified operations and anaesthetics. The devices in use can then range from those seen in modern developed economies through to equipment similar to that used for battlefield anaesthesia (see below). Others opt to mainly use local equipment, adding only their own disposable equipment.

‘District hospital’-based anaesthesia

Many small hospitals in developing countries rely on non-medically qualified assistants to deliver anaesthesia under the supervision of the doctor who will also be performing the surgery. Under these conditions, anaesthetized patients are more likely to be intubated to ensure a secure airway. Most anaesthetists in developing countries work in larger hospitals, but even here they may be responsible for the training and supervision of medical assistants giving anaesthesia. Many such hospitals, large and small, will have storerooms which have become graveyards of anaesthetic machines and other equipment donated by well-meaning organizations or countries, without consideration for the spare parts or expertise needed for their maintenance. There will often be continuous flow (Boyle’s) machines, discarded as the necessary compressed medical gas supply is absent or erratic. In addition, such machines may not have anti-hypoxia devices and vaporizers may be outdated, unserviceable or grossly inaccurate.

For all these reasons, local anaesthetic techniques (nerve blocks, spinals and epidurals) should be used where appropriate.