How medical practitioners monitor anaesthetized patients

							How medical practitioners monitor anaesthetized patients

While maintaining anaesthesia it is essential to monitor the patient. The degree of
monitoring is dependent on the condition of the patient. the type of surgery and the
sophistication and availability of equipment within a particular institution. For each
procedure there are, however, minimum monitoring parameters that must be observed.
The minimum monitoring for any procedure includes monitoring of the heart rate and
blood pressure. Modern opinion is in favour of a continuous ECG.

Respiratory rate and depth. any signs of obstruction. the patient’s colour, the presence
of sweating, lacrimation and muscle movements must be continuously looked for. The
anaesthetist must continuously check that the patient is being supplied with oxygen
and that there has been no disconnection from the oxygen source or obstruction along
the delivery system. All blood loss must be noted and replaced.

The above is the minimum requirement for any patient under an anaesthetic, but
monitoring can be expanded to include various aspects of the cardiovascular system
(e.g. pulsometer. central venous pressure (CVP). Swan-Ganz arterial lines), the
respiratory system (e.g. capnograph). the urogenital system (e.g. urinary catheter),
central nervous system (e.g. EEG, sensory evoked potentials, and temperature) and
neuromuscular system (e.g. electromyogram (EMG), nerve stimulator).

The amount of sophisticated monitoring apparatus can become so vast that one can
lose sight of the patient and his problems: therefore the basic monitoring mentioned
above is always the most important aspect of monitoring and must never be forgotten.
Energy, fluid and electrolyte requirements

The next factor that must be attended to during anaesthesia is energy. fluid and
electrolyte requirements. In the adult. short periods without any energy substrate are
well tolerated; in neonates and infants, however, this is not so, and it is essential that
dextrose be provided during anaesthesia. The maintenance of fluid balance is essential
for all patients because of the large shifts in fluid spaces occurring within the body
during anaesthesia and surgery. Intravenous fluids are necessary for all but the smallest
procedures.

The amount of fluid required intra-operatively is dependent on the period of starvation
prior to surgery, the type, extent and site of surgery, the mass of the patient and the
degree of blood loss. It is essential that the volume of fluid circulating should be
adequate, thus maintaining perfusion of all essential organs and ensuring that the
kidneys continue to function and are enabled to rid the body of waste products.

For adults a solution resembling plasma in its electrolyte concentration is preferred for
fluid maintenance and replacement during anaesthesia. A blood loss in excess of
10-15% of the blood volume should always be replaced with blood. In certain
circumstances blood will be replaced earlier. When giving blood it must be checked that
it is for the correct patient. It should also be warmed and filtered prior to delivery into the
body. Maintenance of temperature is also extremely important.

Theatre temperature and humidity will help to conserve body temperature. During a
long and extensive procedure, however, loss of temperature is inevitable and a warming
blanket and warmed solutions should be used. At the end of the procedure, anaesthesia
must be reversed (i.e. terminated). This requires that the patient wake up and any
residual paralysis be reversed.