A 36-year-old male is undergoing a major surgical procedure under general anesthesia. A fluorinated inhaled anesthetic (isoflurane) is used to achieve the desirable depth of central nervous system depression. An increase in which of the following parameters is most likely to happen during the anesthesia in this patient?

Question

A 36-year-old male is undergoing a major surgical procedure under general anesthesia.  A fluorinated inhaled anesthetic (isoflurane) is used to achieve the desirable depth of central nervous system depression.  An increase in which of the following parameters is most likely to happen during the anesthesia in this patient?

Quizplus · Accepted Answer

General anesthesia encompasses loss of consciousness, analgesia, amnesia, skeletal muscle relaxation and inhibition of reflexes. This complex of symptoms occurs due to the inhibition of electrical activity of neurons. Most of inhalation anesthetics, barbiturates, and benzodiazepines achieve CNS depression by influencing GABA receptors and increasing the inhibitory action of GABA. Inhaled anesthetics have also been shown to affect potassium channels in the neuronal membranes and lock them in the state of hyperpolarization. They may also affect nicotinic and glycine receptors. Apart from their desirable action on CNS, inhalation anesthetics affect almost all organ systems of the body. (Choices A and B) Renal function in general anesthesia is characterized by decrease in glomerular filtration rate and decrease in renal plasma flow. (Choice C) Fluorinated anesthetics are myocardial depressants. They decrease cardiac output which leads to hypotension. (Choice D) Fluorinated anesthetics decrease hepatic blood flow. Educational Objective: Almost all volatile anesthetics increase cerebral blood flow. It is an undesirable effect as it results in increased ICP. Other important effects of inhalation anesthetics are myocardial depression, hypotension, respiratory depression and decreased renal function.

A 36-Year-Old Male Is Undergoing a Major Surgical Procedure Under