Posts: 3,675,937
Threads: 734,344
Joined:
Sep 2021
Reputation:
5
A 68-year-old male with diverticulitis develops an abdominal abscess and becomes septic. His temperature is 40.0 C (104 F), blood pressure 84/40 mmHg, heart rate 130/min, and respiration rate 34/min. He is brought emergently to the operating room for an exploratory laparotomy, sigmoidectomy, and Hartmann's pouch. The patient has a tracheostomy from a previous laryngectomy secondary to laryngeal cancer. The anesthesiologist decides to induce anesthesia with an inhalational anesthestic through the tracheostomy site. Which of the following factors will prolong the induction of anesthesia?
A. High cardiac output
B. High inspired anesthetic concentration
C. Lipid insoluble inhalational anesthetic
D. High alveolar ventilation
E. Low anesthetic blood:gas coefficient
Posts: 3,675,937
Threads: 734,344
Joined:
Sep 2021
Reputation:
5
induction f anesthesia is a time when we try to equilibrate pressures of the gas between alveoli and cerebral tissue: blodd/gas partition.
E
Posts: 3,675,937
Threads: 734,344
Joined:
Sep 2021
Reputation:
5
NOPE
Choice (A) is the correct answer. Onset of anesthesia is determined by a number factors, some of which include cardiac output, anesthetic solubility, anesthestic concentration in inspired air, alveolar ventilation, and the difference between alveolar and mixed venous partial pressure of the anesthestic gas. Increasing cardiac output results in a delay in the onset of anesthesia. This seems counter intuitive but results from the fact that in high cardiac output states, pulmonary blood flows very quickly through the alveoli which results in less time for the anesthetic gas to equilibrate. Anesthestic solubility plays a major role in the onset of anesthesia. Lipid insoluble anesthetics result in a more rapid induction and recovery from anesthesia. Increasing inspired anesthetic gas concentration increases the onset of anesthesia, as does increasing alveolar ventilation. The blood:gas partition coefficient is a measurement of solubility. For example, a blood:gas partition coefficient of 2.0 means that at equilibrium the concentration of anesthetic dissolved in the blood will be twice the concentration in the gas or alveolar phase. When conceptualizing anesthetic solubility, think of the blood as a sponge: anesthetics with a high blood:gas partition coefficient are very blood soluble. It will take longer for the partial pressure of the anesthetic agent to rise, because the blood is acting like a sponge by dissolving much of the anesthetic. The other choices are incorrect.
