الفهرس 
GENERAL ANAESTHESIA
Preparation for General AnaesthesiaOnly 14 pages are availabe for public view
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Abstract
General anaesthesia (GA) is the state produced when a
patient receives medications for amnesia, analgesia,
muscle paralysis, and sedation. An anaesthetized patient can be
thought of as being in a controlled, reversible state of
unconsciousness.
Delayed emergence from anaesthesia is failure of the
patient to regain the expected level of concioussness within 20
to 30 minutes from the end of anaesthetic administration, it
remains a cause of concern for both anaesthesiologist and
surgeon.
Time to emerge from anaesthesia is very variable and
depends on many factors related to the patient, the duration and
type of anaesthetic given, surgical factors and metabolic
fatctors.
Patient factors:
Include extremes of age, genetic variation, body habitus,
co-morbidities, OSA, Cognitive dysfunction, seizures, stroke.
Drug factors:
Premedication, dose, absorption, distribution, metabolism,
excretion and drug interactions.Surgical causes:
Length of surgery and anaesthesia, use of muscle
relaxant, regional techniques with sedation and intracranial
surgeries.
Metabolic causes:
Hypo/hyperglycemia, hypo/hypernatremia, hypokalemia,
hypothermia/hyperthermia especially malignant hyperthermia.
Endocrinal causes:
Myxedema coma, adrenal insufficiency, addisonian crisis
and sheehan’s syndrome may account for delayed recovery.
Respiratory causes:
Postoperative respiratory failure due to primary muscle
problems, metabolic imbalance, obesity, residual NMB, or
pulmonary disease may result in hypoxemia and hypercapnia.
Neurological causes:
Failure to regain consciousness after general anaesthesia
may result from neurologic insult caused by: cerebral
haemorrhage, cerebral embolism, and cerebral ischaemia.
As delayed recovery from anaesthesia is often
multifactorial, systemic approach to clinical evaluation is
mandatory. Basic care (Airway, breathing, circulation).
Heart rate, blood pressure, ECG and peripheral perfusion,
conscious level and urine output should be assessed.
Resuscitate as indicated.
History, investigations and perioperative management,
including the anaesthetic chart and timings of the drug
administration have to be reviewed looking for possible
cause of the delay in recovery.
Close monitoring of core temperature.
Blood glucose level should be checked.
Arterial blood gas analysis.
Full neurological examination should be performed, looking
particularly for localising signs with further imaging (CT,
MRI).