Anesthesia Flashcards
Devices used to secure and manage patient’s airways:
Laryngeal mask airways (LMAs)
Laryngoscopes
Video laryngoscopy devices
Fiberoptic bronchoscopes
Endotracheal tubes (ET tubes)
Oral and nasopharyngeal airways
Types of anesthesia (5)
General
Regional
Monitored Anesthesia care (MAC)
Moderate sedation
Local anesthesia
General anesthesia:
Drug-induced reversible state of unconsciousness
Amnesia, analgesia, loss of responsiveness, decreased stress response, loss of skeletal muscle reflexes (varying degree)
Regional anesthesia:
Injection of local anesthetics near nerve fibers to cause reversible loss of sensation over an area of the body.
Spinal, epidural, peripheral nerve blocks
Monitored anesthesia care (MAC):
Anesthesiologist monitors the patient, administers sedatives and other agents needed
Moderate sedation:
Administration of sedative, analgesic, and/or anxiolytic (benzos) agents by a MD or under MD supervision.
Local anesthesia:
Infiltration of topical administration of agents to anesthetize a part of the body. Typically used for minor procedures, does not involve a MD or sedation.
3 Phases of anesthesia
Induction (Phase 1)
Maintenance (Phase 2)
Emergence (Phase 3)
Anesthetics used in IV induction
Propofol
Etomidate
Methohexital and ketamine
- Narcotics (fentanyl) and/or sedatives (midazolam) are often given during induction or as premedication
Inhalational induction
Patient breathes in anesthetic by face mask
Sevoflurane with or without nitrous oxide is a common choice
Patients receiving an inhalation induction may become agitated and thrash as they lose consciousness
Muscle relaxants:
Often given during induction and maintenance of anesthesia. Used to facilitate intubation and/or optimize surgical conditions
Succinylcholine: SHORT ACTING muscle relaxant agent that causes muscle twitches (fasiculations)
Intermediate- acting: Cistracurium, atracurium, rocuronium, vecuronium
Long-acting: Pancuronium
Options for maintaining the airway
Mask ventilation
Supraglottic airway device (LMA)
ET tube
Inhalational maintenance:
Sevoflurane, isoflurane, desflurane- used for inhalational maintenance
TIVA:
Total intravenous anesthesia is a technique for maintaining anesthesia using infusions or short acting IV agents without inhalational anesthetics
Propofol and remifentanil commonly used
Succinycholine reversal agent
NONE!
Muscle relaxants can be reversed with
neostigmine or edrophonium
Reversal agent for Rocuronium, vecuronium and pancuronium
Sugammadex
Benzodiazepine (Midazolam) reversal agent
Flumazenil
Narcotics (fentanyl) can be reversed with
Naloxone
NPO Guidelines for clear liquids
2 hours
NPO guidelines for breast milk
4 hours
NPO guidelines for infant formula
6 hours
NPO guidelines for nonhuman milk
6 hours
NPO guidelines for light meal (toast and a clear liquid)
6 hours
NPO guidelines for fried foots, fatty foods, meat
8 hours
Local anesthetics commonly used for regional anesthesia include:
Lidocaine
Bupivacaine
Ropivacaine
Additional drugs such as epinephrine (increase density and duration of regional block) and bicarbonate (added to reduce the acidity of local anesthetic and speed the onset of block) can be added to local anesthetic
Signs of LAST (Local Anesthetic Systemic Toxicity)
Ringing in ears
Tingling around the lips
Metallic taste in mouth
Dizziness
LAST can progress to SEIZURES 222377and respiratory or cardiac arrest
Complications that can occur during anesthesia
Difficult airway
Laryngospasm
Cardiac problems
Hemorrhage
Anaphylaxis
Hypo/Hyperthermia
Initial signs of malignant hyperthermia
Tachycardia and hypertension- common initial signs
Increased end-tidal carbon dioxide is the most specific sign of MH
Muscle rigidity
Mottling of skin
Ventricular dysrhythmia
Hyperthermia, myoglobinuria
Drug used to treat MH
Dantrolene!
Dilute with sterile water for injection
Adverse effects of hypothermia in surgery
vasoconstriction
Coagulation/platelet function impairment
Prolonged time for medications to take effect
Surgical site infection
Myocardial ischemia
Increased length of stay
ASA Class 1:
Normal healthy patient
ASA 2:
Patient with mild systemic disease
ASA 3:
Patient with severe systemic disease
ASA 4:
Patient with severe systemic disease that is a constant threat to life
ASA 5:
Moribund patient who is not expected to survive without the operation
ASA 6:
Declared brain-dead patient whose organs are being removed for donor purposes
Phase 1:
Induction
anesthetic agents are administered to “put the patient to sleep” IV agents (most adults) or inhalational agents (many small children) can be used
Phase 2:
Maintenance
Provider continues to administer inhalational and/or IV agents to keep the patient anesthetized
Phase 3:
Emergence
Anesthetic agents are discontinued and/or reversed and the patient is allowed to “wake up”
Spinal anesthesia
subarachnoid space is entered and local anesthetic is injected directly into the spinal canal
Potential complications of spinal anesthesia
hypotension may be caused by vasodilation
high spinal can compromise respiration
spinal headache may occur postop. Younger patients more susceptible, size of needle and design of the needle’s point affect incidence
Epidural anesthesia
Space between the ligamentum flavum and dura
Space is ID’d by a loss of resistance as the needle is advanced. single dose of anesthetic can be injected or a catheter can be placed
Complications:
dura puncture
subarachnoid injection
intravascular injection
Bier blocks can be used for
procedures on the hand, wrist or forearm
anesthetic effect lasts until the tourniquet is deflated.
Most specific sign of MH is
Increased end-tidal carbon dioxide
Most common signs of MH that are not specific
Tachycardia and hypertension are most common initial signs but not specific to MH
Drug used to treat MH
Dantrolene
Protocol for treatment of MH
Stopping the surgery is possible and DC inhalational agents and succinylcholine
Getting the MH cart and dantrolene
Calling for help
Hyperventilating with 100% oxygen at a flow of 10L/min
Give 2.5mg/kg dantrolene rapidly by IV. repeat as needed until patient responds. Consider alternate diagnosis if more than 10mg/kg given without response
obtain ABG’s
Cooling the patient if core temp is greater than 39 Celsius. Stop cooling if temp decreased to less than 38 Celsius
Provide appropriate treatment for dysrhythmias and abnormal electrolytes
