anesthesia and malignant hyperthermia

general anesthesia

• reversible unconscious state characterized by amnesia, analgesia, depression of reflexes, and muscle relaxation

• pt usually intubated

monitored anesthesia care (MAC)

• aka conscious sedation

• pts can respond to commands or light stimulation

• no artificial airway needed

• local anesthesia supplemented with IV meds to provide sedation and amnesia

regional anesthesia

• reversible loss of sensation in specific area of body after purposeful injection of local anesthetic using ultrasound guidance

• pt may be awake or mildly sedated

• eliminates pain at operative site

• ex: spinals, epidurals, caudals, major peripheral nerve blocks

local anesthesia

• used for relatively short procedures, NPO status not needed

• is applied directly to operative site

• pt awake and able to respond

• anesthesia provider not involved

• periop nurse will monitor pt during procedure

nitrous oxide, desflurane, isoflurane, sevoflurane

types of inhalation gases

nitrous oxide

inhalation gas that’s used for induction, does not cause muscle relaxation

desflurane

inhalation gas that aids in emergence (waking up), provides relaxation

isoflurane

anesthetic gas that provides relaxation and maintains CO

sevoflurane

anesthetic gas that provides rapid induction and good relaxation, mainly used for peds

succinylcholine, atracurium, rocuronium, pavulon

types of muscle relaxants

succinylcholine

muscle relaxant that has rapid onset and short duration, risk of MH, requires refrigeration

atracurium

muscle relaxant that has no cumulative effects, good for renal failure pts, requires refrigeration

rocuronium

muscle relaxant with rapid onset, eliminated by kidneys/ liver

pavulon

muscle relaxant that had longer duration, eliminated by kidneys

diazepam, ketamine, midazolam (Versed), propofol

types of IV anesthetics

diazepam

IV anesthetic that’s used for amnesia and sedation, has long duration

ketamine

IV anesthetic used for induction, short acting, pt can maintain airway, good for small children and burn pts

midazolam (Versed)

IV anesthetic that’s an anxiolytic, hypnotic, and sedative, is short acting

propofol

IV anesthetic used for induction and maintenance, used in MAC, rapid onset, pt will awaken in 5-10 minutes

ASA scoring

• used to help assess risk of surgery/ anesthesia events

• measures severity of systemic disease, physiologic dysfunction, and anatomic abnormalities

• done by anesthesia provider

nurse’s role during induction

• stay by pt to provide reassurance and comfort

• assist anesthesia provider with intubation (may be asked to provide cricoid pressure)

• keep room as calm as possible

• limit talking and excess noise

• avoid counting during this period

malignant hyperthermia

hypermetabolic condition of skeletal muscle cells triggered by meds commonly used in anesthesia

hypercapnia, tachycardia, tachypnea, hypoxia, acidosis, dysrhythmias, muscle rigidity, elevated body temp 1-2 degrees every 5 minutes, hyperkalemia, hypercalcemia

s/s of malignant hyperthermia

desflurane, isoflurane, methoxyflurane, sevoflurane, succinylcholine

common triggers of malignant hyperthermia

dantrolene sodium

med to treat malignant hyperthermia

treatment of malignant hyperthermia

discontinue anesthetic agents, terminate surgery if possible, hyperventilate with 100% O2, give dantrolene sodium, begin active cooling, monitor temp, maintain urine output, correct acidosis/ dysrhythmias/ hyperkalemia, transfer to ICU