Anesthesia Principles Lecture Powerpoint Flashcards
Anethesia definition
State of controlled temporary loss of sensation or awareness that is induced for medical purposes, can include analgesia, paralysis, amnesia, and unconsciousness
General anesthesia
State that produces amnesia and analgesia with or without reversible muscle paralysis, controlled reversible state of unconsciousness involving combo of inhaled and IV medications, some benefits include good control and adaption, rapid administration, and can be reversed, but some disadvantages include the pre-op prep, cost, nausea, malignant hyperthermia, and emergence delirium as side effects
Physical exam findings a anesthesiologist focuses on during assessment
-head and neck findings such as poor dentition, large tongue, immobile neck, difficulty obtaining IV access
Mallampati scoring (I-IV)
A scoring system assessing how visible anatomic structures are in the back of the throat to determine the ease or difficutly of intubation, class I sees everything, class II loses pillars and tips of uvula but still has soft and hard palate, class III can only see base of uvula and hard and soft palate and have lost pillars, class IV has lost everything, class III and IV will see difficulty intubating
Thyromental distance
Measured from thyroid notch to tip of jaw with head extended to determine if less than 6.5cm, if it is less then suggests difficult intubation will be present
NPO rules pre op (4)
- No solid food 6 hours prior
- no clear fluids 2-4 hours prior
- don’t take any anticoagulants, ACEs, herbs and vitamins
- B blockers the morning of surgery is recommended and protective
Essentials to monitor under general anesthesia intraop
- Have IV access peripheral or central
- heart monitor
- noninvasive BP
- temp
- pulse ox
- end tidal CO2
General anesthesia induction steps (6)
1) preoxygenation either by mask or nasal canula
2) sedative drug via IV access (propolol, ketamine, thiopental, or midezelam)
3) analgesic drug administered (morphine, fentanyl, dilaudid)
4) paralytic drugs (succinylcholine, rocuronium)
5) establish endotrachial tube placement
6) anesthesiologist begins maintenance anesthesia (nitrous oxide, isoflurane)
Sedative and analgesic used in intubated patients post op that will go to ICU
Propophol and fentanyl
Sedation/monitored anesthesia care (MAC)
Type of anesthesia technique where patient is responsive and maintains airway, continuum either light to moderate to deep sedation, used with local or regional anesthesia, benefits include keeping patients awake and avoiding hemodynamic instability, risks include over sedation or patient discomfort
Regional/local anesthesia
Reversible loss of sensation over a specific body area without producing unconsciusness, includes spinal, epidural, peripheral nerve blocks, local/field, and topical anesthesias, benefits include preservation of cerebral function, general less hemodynamic effect, improved early mobilization, but disadvantage is time consumption, patient discomfort, risk of nerve injury
Spinal vs epidural anesthesia
A spinal sees injection of anesthetic drug into subarachnoid space below L1-2, rapid acting and good for lower limb or pelvic surgeries vs injection of anesthetic drug into epidural space at any level, is slower acting, uses medication thru an indwelling catheter and requires multiple dosing and is most often used in lower limb, pelvic surgery, and child delivery
Peripheral nerve blocks
Injection of anesthetic around peripheral nerve or plexus, single injection typically, used for intra op anesthesia or post op pain relief, not associated with nausea/vomiting, headaches, or hypotension
Malignant hyperthermia
Life threatening clinical syndrome of hypermetabolism involving the skeletal muscle triggered by inhaled certain anesthetic agents and paralytic agent succinylcholine***, autosomal dominant inherited with reduced penetrance (not always received but is dominant) - not an allergy! Sees large quantities of calcium released from SR of skeletal muscle causing hypermetabolic state and aerobic and anaeroic metabolism producing heat, acidosis, and rigidity
Malignant hyperthermia signs and symptoms (5 early and 6 late)
- arterial CO2
- tachypnea
- flushing
- rigidity or masseter spasm
- pyrexia
- mottled skin and cyanosis
- rhabdo
- DIC
- cerebral edema
- death