Causes of pH Disturbances-- Metabolic vs. Respiratory Acidosis and Alkalosis

Concept: Metabolic Acidosis

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Concept: Metabolic Alkalosis

1m

Concept: Respiratory Acidosis

3m

Concept: Respiratory Alkalosis

2m

Problem: A 20-year-old male presents to his physician with a two-day history of severe nausea and vomiting. This started a few hours after he attended an outdoor BBQ with his fraternity where he ate, among other things, potato salad that had been sitting in the sun all day. Since then he has been vomiting approximately once every two hours. His bloodwork shows a blood pH of 7.49. Which of the following describes this patient’s state?

2m

Problem: An 8-year-old intellectually disabled male is brought to the emergency department by his mother, who reports that he ate a whole bottle of Tums (which are tablets of calcium carbonate [CaCO3]). His bloodwork shows a blood pH of 7.48. Which of the following describes this patient’s state?

2m

Problem: A 17-year-old woman presents to psychiatry with a three-year history of severely restricted eating and dramatic weight loss. She reports near-incessant thoughts about her weight, specifically an overwhelming fear of gaining weight. She is diagnosed with anorexia nervosa and is admitted to the inpatient ward for monitoring and refeeding. On admission, her bloodwork reveals a blood pH of 7.32. Which of the following describes this patient’s state?

2m

Problem: A 65-year-old woman presents to the emergency department with the feeling that she can’t get enough air. She was diagnosed with amyotrophic lateral sclerosis (ALS; a neurodegenerative disease that slowly causes paralysis) thirty years ago. Pulmonary function testing shows that she has a tidal volume (the amount of air she moves with a normal breath) of 200 mL (normal is ~500 mL). Her bloodwork shows a blood pH of 7.3. Which of the following describes this patient’s state?

2m

Problem: A 22-year-old undergraduate presents to the emergency department with a two-hour history of heart palpitations and a strong feeling “like [he’s] going to die.” This started a few minutes after learning that he failed his organic chemistry class, which he needs to graduate; he now has to spend a whole additional year in school. He cannot afford this additional year of school. He is breathing at a rate of 36 breaths per minute (normal: ~16 breaths/minute). His blood work shows a blood pH of 7.33. Which of the following describes this patient’s state?

2m