Summary

In study session I you have learnt

• Maintenance of general anesthesia is continuation anesthesia following induction to ensure the patient is in state of hypnosis, pain free and relaxed while the patient vital sign and other are maintained.
• The continued popularity of volatile anesthetics for maintenance of anesthesia is due primarily to their rapid reversibility and ease of administration for titrating to the desired end point.
• Various different agents have been employed for intravenous techniques. Ketamine has proved useful in the developing countries and Propofol is currently popular in developed countries for total intravenous anesthetics.
• It is necessary to administer a combination of intravenous drugs that provide for hypnosis, amnesia, maintain blood pressure and pulse, analgesia, and muscle relaxation.
• Assessing depth of IV anesthesia based changes in muscle tone, respiratory rate and pattern, autonomic hyperactivity such as tachycardia, hypertension, lacrimation, and diaphoresis in light anesthesia are sensitive clinical signs of in adequate depth of anesthesia as well as titrating IV anesthetics.
• Following intubation, muscle paralysis may need to be continued to facilitate surgery. Maintenance doses should be guided by the nerve stimulator and clinical signs such as spontaneous respiratory efforts or movement
• Recall after surgery under general anesthesia can be a psychological disaster from which the victim may take months to recover. It is always linked to a general anesthetic technique which has employed muscle relaxation and artificial ventilation.
• In some high-risk surgeries, such as trauma, cardiac surgery, emergency cesarean delivery, or in situations involving a patient whose condition is unstable, using the usual dose of anesthetic drugs could harm the patient. In these and other critical or emergency situations, awareness may not be completely avoidable because the patient cannot be put safely into a deeper anesthetic state. Prevention is administering sufficient dose of hypnosis, avoiding unnecessary use of muscle relaxants, continuous monitoring of depth of anesthesia and maintain balanced anesthesia to the level of surgical or diagnostic procedures.
• Ventilation can be spontaneous breathing or controlled ventilation depending on the depth of anesthesia, usage of muscle relaxants, invasiveness of the procedure and the need to control the air way.
• When using intermittent positive pressure tidal volume, respiratory frequency, inspiratory and expiratory time ratio, airway pressure should be adjusted according the patients age and weight considered.
• The common anesthesia incidents such as cyanosis, hypotension, hypertension, respiratory failure and bronchospasm should identify promptly and treated.