Anesthesia Student Survival Guide.pdf - Index of

166 ● AnesthesiA student survivAl Guide
pharmacogenetics, age, sex, co-morbidities, and home medication regimen. An
anesthesiologist must be prepared to rescue a patient who was intended to have
minimal sedation, but ends up being deeply sedated. Similarly, the anesthesiologist
must be able to convert from sedation to general anesthesia. Drugs
commonly used during anesthesia sedation may include midazolam, propofol
(sedation dose: 30–100 mcg/kg/min), ketamine, fentanyl, remifentanil, and
dexmedetomidine (see Chap. 4, Table 4.7).
Choice of Anesthetic Technique
In choosing an appropriate level of sedation and anesthetic technique, the
anesthesiologist evaluates:
1. the type of procedure
2. patient comorbidities/health status
3. the preference of the surgeon
4. the preference of the patient
The primary concerns when considering whether or not a patient can tolerate
deep sedation and general anesthesia are the airway and cardiovascular status.
For a patient with severely depressed cardiovascular function who is scheduled
to undergo a procedure on a distal extremity, it may be wiser to choose an anesthetic
technique other than general anesthesia which could further depress their
cardiac function. Similarly, an anesthesiologist may choose general anesthesia
for a healthy patient who is undergoing a procedure that normally only requires
conscious sedation but has a full stomach or severe gastrointestinal reflux, in
which case protection from aspiration of gastric contents is important.
The goal of an anesthetic is to allow a patient to tolerate a procedure with the least
degree of discomfort and the greatest degree of safety. For minor procedures, this
may mean injecting local anesthetic to block the transmission of pain and administering
a benzodiazepine for anxiolysis. However, for major procedures that require
patients to be completely immobile, their level of consciousness deeply depressed,
and their muscles paralyzed, it will usually mean inducing general anesthesia.
General Anesthesia
General anesthesia implies the loss of consciousness and protective airway
reflexes. A patient under general anesthesia will not respond purposefully to
noxious stimuli. The main goals of general anesthesia are to provide adequate
hypnosis, relaxation, amnesia, immobility, and analgesia. General anesthesia can be