A 65-year-old man is admitted to the intensive care unit from the operating room after a triple coronary artery bypass graft. He is intubated and on a ventilator. Lactic acid levels were normal postoperatively, but now they are rising. The increased level could be an indication of:
- A. excessive sedation
- B. bowel ischemia
- C. excessive volume infusion in the operating room
- D. mild hypothermia postoperatively
Correct Answer: B
Rationale: In this scenario, the rising lactic acid levels in a 65-year-old man after a coronary artery bypass graft could indicate bowel ischemia. Bowel ischemia can lead to anaerobic metabolism, causing an increase in lactic acid levels. Excessive sedation may cause respiratory depression but would not directly lead to rising lactic acid levels. Excessive volume infusion in the operating room might cause fluid overload but would not typically result in rising lactic acid levels. Mild hypothermia postoperatively could lead to shivering and increased oxygen consumption, but it is less likely to be the primary cause of rising lactic acid levels in this context.
You may also like to solve these questions
Which of the following birthmarks usually fade or regress as the child gets older?
- A. Hemangiomas
- B. Congenital dermal melanocytosis (i.e., Mongolian spots)
- C. Macular stains
- D. Hemangiomas, congenital dermal melanocytosis (i.e., Mongolian spots), and macular stains
Correct Answer: D
Rationale: The correct answer is Hemangiomas, congenital dermal melanocytosis (i.e., Mongolian spots), and macular stains. These three types of birthmarks are known to fade or regress as the child gets older. Hemangiomas are vascular birthmarks that often shrink and disappear over time. Congenital dermal melanocytosis, commonly known as Mongolian spots, usually fade by adolescence. Macular stains, also called salmon patches, tend to lighten and fade as a child grows. The other choices are incorrect because they do not typically fade or regress with age.
Which of the following patients are at higher risk for developing oral cancer?
- A. A female who has taken oral contraceptives for the last 4 years
- B. Both an adult male with a history of alcoholism and a middle-aged male who smokes a pipe
- C. An adult female who eats spicy foods regularly
- D. An older adult female who chews gum frequently
Correct Answer: B
Rationale: The correct answer is 'Both an adult male with a history of alcoholism and a middle-aged male who smokes a pipe.' Alcohol consumption and tobacco use, such as smoking a pipe, are well-known risk factors for developing oral cancer. These two factors significantly increase the likelihood of developing oral cancer compared to the other choices. Taking oral contraceptives, eating spicy foods regularly, and chewing gum frequently are not established risk factors for oral cancer, making them less likely to lead to the development of this type of cancer.
A 30-year-old has poorly controlled asthma and is taking prednisone 10 mg by mouth once a day. He has been on this regimen for 6 weeks. Abrupt withdrawal or discontinuation of this medication can cause:
- A. adrenal crisis
- B. hypercortisolism
- C. ACTH stimulation
- D. thyroid crisis
Correct Answer: A
Rationale: Abrupt withdrawal or discontinuation of prednisone, a corticosteroid, can lead to adrenal crisis. This occurs due to the suppression of the adrenal glands' natural cortisol production caused by prolonged exogenous steroid administration. Adrenal crisis presents with symptoms such as weakness, fatigue, abdominal pain, and hypotension. Hypercortisolism (Cushing syndrome) results from chronic excessive exposure to cortisol, not abrupt withdrawal. ACTH stimulation would be expected in response to low cortisol levels, not as a direct consequence of prednisone withdrawal. Thyroid crisis (thyroid storm) is associated with severe hyperthyroidism and is not directly related to corticosteroid withdrawal.
What is a cause of the crystallization within the synovial fluid of the joint affected by gouty arthritis?
- A. Destruction of proteoglycans
- B. Underexcretion of uric acid
- C. Overexcretion of uric acid
- D. Increased absorption of uric acid
Correct Answer: B
Rationale: The correct answer is B: Underexcretion of uric acid. In gouty arthritis, the crystallization within the synovial fluid of the affected joint is caused by the underexcretion of uric acid, leading to the accumulation and subsequent crystallization of urate crystals. Choice A, destruction of proteoglycans, is incorrect as it is not directly related to the crystallization process in gouty arthritis. Choice C, overexcretion of uric acid, is incorrect because gout is primarily associated with underexcretion or decreased excretion of uric acid rather than overexcretion. Choice D, increased absorption of uric acid, is also incorrect as the primary issue in gouty arthritis is the body's inability to properly eliminate uric acid.
A woman is complaining that she feels like the room is spinning even though she is not moving. Which of the following is characteristic of benign positional vertigo?
- A. It usually occurs with a headache.
- B. Pupillary changes are common.
- C. It is usually triggered when the patient bends forward.
- D. Nystagmus continues even when eyes fixate on an object.
Correct Answer: C
Rationale: Benign positional vertigo is typically triggered by changes in head position, such as bending forward or turning over in bed. This change in position leads to brief episodes of vertigo, often associated with nystagmus, which is rapid, involuntary eye movements. Pupillary changes and headaches are not typical features of benign positional vertigo, making choices B and A incorrect. Nystagmus in benign positional vertigo usually stops when the eyes fixate on an object, so choice D is also incorrect.