Anaesthesia

Question 1

What are the different stages of anaesthesia (Geudel, 1937)

Answer 1

1. Induction
   - Period immediately after administration of induction agent
   - Progress from analgesia to amnesia
   - Patients can carry on a conversation at this time
   - Ends at loss of consciousness = no longer alert and orientated
2. Excitement
   - Period following loss of consciousness
   - Marked by excited and delirious activity
   - Respirations and HR become irregular
   - Uncontrolled movements, vomiting, breath holding & pupillary dilation
   - May lead to airway compromise, must be managed
3. Surgical/operative
   - Skeletal muscles relax and vomiting stops
   - Respiratory depression occurs
   - Eye movements slow and stop = patient is now ready for surgery
   - Depending on anaesthetic depth, it can be divided into 4 planes:
4. Overdose/danger
   - Too much medication administered relative to stimulation
   - Patient has severe brainstem and medullary depression
   - Results in a cessation of respiration
   - Leads to cardiovascular collapse
   - This stage is lethal without CV and respiratory intervention