Chandy Temperature Flashcards
Halothane and suxamethonium anesthesia was given to a 10 year old male for the suture of an olecranon process. Anesthesia had proceeded for 10 min when the face was uncovered to display moderate cyanosis despite rich oxygen intake. General rigidity was commencing at this stage. Eyeballs were deviated upwards and to the right. The operation was hurriedly concluded and 100% oxygen continued. However rigidity continued and body temperature was now 42oC and then increased to 43oC in a few minutes. Over the course of an hour the pulse slowed and respiratory function failed a few minutes before death – 1 hour and 45 min after commencing the anesthetic.
The following statements regarding this case history are TRUE EXCEPT:
Select one:
a. The anesthetics cause a hypermetabolic state that consumes oxygen contributing to cyanosis.
b. Mutations of TRPM8 channels may underlie one form of this disease.
c. Increased skeletal muscle metabolism raises muscle temperature to a level that contributes to muscle rigidity.
d. TRPV1 channels are activated when the temperature rises above 42oC
B
A 22-year-old male flipped over while kayaking in the local bay near Kodiak, Alaska. The air was calm and ambient air temperature was 23°C (75°F). W ater temperature was 10°C (50°F). He was able to egress without difficulty, but he did not know how to right the vessel. He was wearing a T-shirt, jeans, and life vest suspenders, which kept him upright. After 2 minutes in the water, he was unable to use his fingers and soon after, he could not effectively use his hands. He began yelling for help. He was rescued by the Coast Guard.
The following statements regarding this case history are TRUE EXCEPT:
Select one:
a. Because the heat transfer-coefficient of water is 100 times greater than air, the man rapidly lost heat.
b. The first intervention is to remove the wet clothes and cover the man in blankets.
c. Moderate hypothermia occurs when the core temperature is 30-34oC.
d. When cold is applied to a cold fiber, the firing rate increases inversely to the temperature i.e. the lower the temperature, the faster the firing rate.
D
Marked hyperthermia which could not be traced to an infectious origin was observed in a 3- year-old child following the aspiration and dissection of a cystic tumor from the third ventricle in the brain. The elevated temperature was not reduced by acetaminophen and there were abnormalities of circadian temperature cycles. In thermal stimulation tests the body temperature was raised above 40oC without evoking physiological heat-loss responses and thermal discomfort.
Which of the following statements is TRUE about this patient?
Select one:
a. Absence of warm temperature receptors in the skin prevents this child from regulating body temperature.
b. Damage to the thermoregulatory center in the anterior hypothalamus prevents this child from initiating heat loss mechanisms.
c. Damage to the thermoregulatory center in the posterior hypothalamus prevents this child from initiating heat loss mechanisms.
d. Absence of cold temperature receptors in the skin prevents the child from dissipating heat.
B
A 67-year-old man presented to the emergency room with complaints of sudden onset of chills, persistent fevers (102.9°F at home) and shoulder pa in. His wife mentioned that she had noticed a rash on his left shoulder in the past 48 hours following several tick bites during a hike.
Which of the following statements is TRUE about this patient?
Select one:
a. The hypothalamic temperature set-point remains unchanged during fever and the increased body temperature is because heat generation is greater than heat loss.
b. During a “crisis” or “flush”, the hypothalamic temperature-control center is suddenly raised to a higher temperature set-point, causing the body temperature to rise rapidly.
c. The anti-rise center in the posterior hypothalamus is responsible for triggering heat-loss mechanisms via cutaneous vasodilatation, sweating and panting.
d. Chills occur during fever because pyrogenic cytokines rapidly elevate the hypothalamic thermoregulatory set point, but the actual core body temperature is cooler.
e. The anterior hypothalamus contains mainly cold receptors and its main role is to sense a drop in temperature.
D
On July 4, 2007, in Oakland County, Michigan, an overweight 14-year-old male was found dead in his home. He had been lifting weights and was wearing only shorts. The heat was on in the home with the temperature set at 29.4oC. The relative humidity was 50%. He had begun a program of lifting weights 2 weeks before his death. The cause of death was acute congestive heart failure caused by strenuous weight lifting and heat exhaustion.
Which of the following statements is TRUE about this patient? (Select the single best answer.)
Select one:
a. Evaporation is greater when the humidity is high, especially during exercise.
b. In an unfit / unacclimatized person exercising in a hot room during summer, nearly all the Na+ and Cl- in the sweat duct is reabsorbed and sweat has a final concentration of 5 mEq/L Na+ and Cl-.
c. When the surrounding environmental temperature is greater than the skin temperature, radiation is the only way to lose heat.
d. Aldosterone enhances reabsorption of Na+ and Cl- during sweating, and an unacclimatized person may lose as much as 15-30 g salt/day.
e. Under normal circumstances in a temperate climate, the body does not lose any heat via sweating.
D
A 30-year old man was taken to surgery for suspected acute appendicitis. He was administered general anesthesia consisting of halothane and succinylcholine. Suddenly the patient developed hyperthermia, muscle rigidity, tachycardia and hypertension. The anesthetist successfully managed the patient by hyperventilating the patient with 100% oxygen, administering dantrolene and initiating cooling.
The following statements regarding this case history are TRUE EXCEPT:
Select one:
a. Drugs that enhance calcium-dependent muscle contraction are frequently used to treat the disease.
b. Anesthetics cause a hypermetabolic state that consumes oxygen contributing to cyanosis.
c. Increased skeletal muscle metabolism raises muscle temperature to a level that contributes to muscle rigidity.
d. Rhabdomyolysis (muscle degeneration) in these patients may contribute to kidney failure.
e. A mutation of the ryanodine receptor may underlie one form of this disease.
A
A 33-year-old female slipped overboard from a boat near Patagonia, Chile. The air was calm and ambient air temperature was 23°C. Water tempera ture was 8°C. She was wearing a T-shirt, jeans, and life vest suspenders, which kept her upright. After 2 minutes in the water, she was unable to use his fingers and soon after, she could not effectively use her hands. She began yelling for help and was rescued by a sailing boat that was passing by.
The following statements regarding this case history are TRUE EXCEPT:
Select one:
a. Because the heat transfer-coefficient of water is 100 times greater than air, the woman rapidly lost heat.
b. The anti-drop center in the anterior hypothalamus is responsible for triggering the heat-producing and heat-conserving mechanisms in the body.
c. When cold is applied to any cold fiber, the firing rate increases inversely to the temperature i.e. the lower the temperature, the faster the firing rate.
d. Moderate hypothermia occurs when the core temperature is 30-34oC.
B or C
A patient waiting to see his doctor is sitting in a room in which the air temperature is 21oC (70oF), wearing only a thin gown that is open in the back. The majority of her body heat will be lost by which of the following? Select one: a. Evaporation of sweat b. Radiation and conduction c. Breathing d. Cutaneous vasoconstriction e. Horripilation
B
A 26-year-old medical student is admitted to the hospital with a traumatic brain injury following a motor cycle accident in Orange County. He develops a fever of 39oC, which is unrelated to infection or inflammation.
Which of the following causes is responsible for the raised temperature?
Select one:
a. A lesion in the posterior nucleus
b. A lesion in the anterior hypothalamus
c. A lesion in the paraventricular nucleus
d. A lesion in the lateral hypothalamus
e. A lesion in the arcuate nucleus
B
A 43-year old man developed malignant hyperthermia following halothane anesthesia during abdominal surgery. The increase in body temperature may be attributed in some patients to mutations in the ryanodine receptor in skeletal muscle, resulting in which of the following?
Select one:
a. Rapid repetitive firing of presynaptic terminals of motor neurons
b. Failure of skeletal muscle cells to repolarize
c. Excessive calcium release from the sarcoplasmic reticulum during muscle contraction
d. Production of pyrogenic cytokines
e. Lesion in the praventricular nucleus
C
