General Anasthetia Flashcards
As this patient awakens from a general anesthetic for an arthroscopy, he coughs, moves his arm, squirms on the table, and phonates when touched by the surgeon. He does not open his eyes or squeeze his hand on command. Which of the following is most accurate?
Movement and phonation indicate that the patient is “awake.”
The patient is emerging from anesthesia. Since he can phonate, he can protect his airway.
Stage II is the stage at which the risk of complications is greatest.
This stage of anesthesia is observed more frequently at induction than emergence.
The correct answer isC.
Explanation: During Stage II of anesthesia, patients are hyperexcitable to external stimuli, and may phonate, move, manifest autonomic instability including arrhythmias, and cannot protect their airways. This is the stage at which the risk of complications is greatest. Because of the rapidity with which patients receiving intravenous induction agents pass through Stage II, this stage of anesthesia is observed more frequently at emergence than induction. The patient’s ability to phonate is not related to his ability to protect his airway.
A 30-year-old man presents for open reduction and internal fixation of a left radius fracture as an outpatient. He has smoked 1 pack of cigarettes per day for 12 years. The plan is general anesthesia with endotracheal intubation. Which one of the following agents is most appropriate for him? Isoflurane Sevoflurane Desflurane Nitrous oxide
Correct answer B
sevoflurane is the second fastest volatile anesthetic behind desflurane, and is the least irritating to mucous membranes
A 42-year-old woman presents for laparoscopic gastric bypass. She weighs 191 kg (420 lb) and is 165 cm (5 ft and 5 in) tall. She has a history of hypertension, diabetes mellitus, obstructive sleep apnea, and acid reflux. Because of the sleep apnea, there is concern about mild pulmonary hypertension. Which of the following volatile liquids is most likely to produce the most rapid emergence in this patient? Isoflurane Sevoflurane Desflurane Nitrous oxide
Answer C
desflurane has the fastest emergence followed by sevoflurane
A 38-year-old man presents for ventral hernia repair. He had a malignant hyperthermia crisis during a prior surgery. Which of the following inhaled anesthetics would be appropriate for this patient? Isoflurane Sevoflurane Desflurane Nitrous oxide
Answer D
You are a resident on anesthesiology service and are considering using nitrous oxide to assist in placing a laryngeal mask airway (LMA) in your patient, who is about to undergo a minor surgical procedure. You remember that nitrous oxide has a very high minimal alveolar concentration (MAC) compared to other anesthetics. This means that nitrous oxide has…
Decreased lipid solubility and decreased potency
Increased lipid solubility and decreased potency
Decreased lipid solubility and increased potency
Increased lipid solubility and increased potency
Answer A
The most sensitive sign of metabolic hyperactivity in malignant hyperthermia is: Tachycardia Hypercapnea Hyperthermia Muscle rigidity Hypertension
Answer B
The IV agent with excitatory effects on the CNS but produces the least cardiovascular disturbance ___________
Etomidate
In contrast to most anesthetics, this agent produces cardiac stimulation, resulting in increased BP, HR, and cardiac output _______
ketamine
All are true regarding propofol as an anesthetic EXCEPT:
Provides skeletal muscle relaxation
Vasodilation may produce a decline in BP. Can be minimized by decreasing dose
Safe alternative for patients predisposed to MH
High lipophilicity provides rapid and smooth onset
A
All are true regarding ketamine as an anesthetic EXCEPT:
Contraindicated in a patient with asthma because it may cause bronchoconstriction
Recovery from anesthesia associated with emergence phenomenon of hallucinations and vivid dreams
Produces dissociative anesthetic state, whereby patient appears awake but is unconscious
Produces analgesia
A
All are true regarding etomidate as an anesthetic EXCEPT:
Inhibits adrenocortical function
No adverse effects from adrenocortical inhibition during short-term use (e.g. induction of anesthesia)
Produces minimal CV effects
Potent hypnotic with excellent analgesic properties
Safe alternative for a patient with hemodynamic instability
D
ketamine works by:
analgesic that works by blocking the NMDA-mediated nociceptive stimuli in the dorsal horn of the spinal cord
TEST: one example of an ideal use for ketamine is;
serial dressing changes in burn victims
ketamine has several behavioral and physiolical responses:
analgesic, pupillary dilation, tachycardia and bronchodilation (increased output from nucleus solitarius due to nmda-mediated inhibition of GABAergic interneurons (disinhibition)
Which of the following can be used to measure anesthetic depth in a patient that has been given a neuromuscular blocking agent?
Jaw tone
Rate and depth of respiration to stimulation
Heart rate and blood pressure
Corneal reflex
Heart rate and blood pressure
Breath-holding, vocalization, and involuntary movement of the arms or legs are most likely an indication that your pediatric patient undergoing a mask induction with sevoflurane is in what stage or plane of anesthesia? Stage III, plane 1 Stage III, plane 2 Stage I Stage II
D. Stage II —Excitation stage (review slide 10)
Effects that can occur with anesthetic administration (e.g. induction) with a dissociative anesthetic: Increased heart rate and blood pressure Hallucinations Increased intracranial pressure Increased salivary secretions All of the above
e
The following paired statements describe two entities that are to be compared in a quantitative sense. Select the single best answer. (X) Risk of hypotension with propofol (Y) Risk of hypotension with ketamine (Y) is greater than (X) (X) is greater than (Y) The two are equal or very nearly equal
Answer is B (Hypotension with propofol is greater than hypotension with ketamine). Discussed in slide 5.
Termination of pharmacologic action of a barbiturate used for induction of anesthesia occurs mainly by:
Metabolism
Redistribution
Excretion
Answer is B…redistribution. Slide 15.
General anesthesia is a drug-induced, state composed of all except for… Unconsciousness Memory loss Analgesia Reduced muscle tone/immobility Sleep Inhibition of nociceptive reflexes A reduction in certain autonomic reflexes
not sleep
