A 34-year-old man with upper gastrointestinal bleeding is brought to the local emergency department by ambulance. He was found in front of a grocery store after customers called emergency medical services. The patient is unable to provide any information, but his medical records show a history of alcohol use disorder. After undergoing emergency evaluation and appropriate resuscitation, his condition stabilizes. Gastric lavage fluid initially contained blood but cleared quickly. Upper endoscopy shows a linear mucosal tear at the gastroesophageal junction. The process directly responsible for causing this patient's mucosal tear will most likely result in which of the following acid-base disturbances?

Question

A 34-year-old man with upper gastrointestinal bleeding is brought to the local emergency department by ambulance.  He was found in front of a grocery store after customers called emergency medical services.  The patient is unable to provide any information, but his medical records show a history of alcohol use disorder.  After undergoing emergency evaluation and appropriate resuscitation, his condition stabilizes.  Gastric lavage fluid initially contained blood but cleared quickly.  Upper endoscopy shows a linear mucosal tear at the gastroesophageal junction.  The process directly responsible for causing this patient's mucosal tear will most likely result in which of the following acid-base disturbances?

Quizplus · Accepted Answer

11ec160b_3ae5_c22f_9249_f91a89ea49da_MD0001_00 This patient has a Mallory-Weiss tear of the gastric mucosa near the gastroesophageal junction. Mallory-Weiss tears are caused by high intragastric pressure being transmitted to the esophagus through a tight lower esophageal sphincter. They are most commonly caused by repetitive retching and vomiting but can also occur with straining during defecation or heavy lifting, seizures, blunt abdominal injury, and upper gastrointestinal endoscopy. Repetitive vomiting leads to metabolic alkalosis due to net loss of acidic gastric secretions. (Choice A) Unlike methanol or ethylene glycol, acute ethanol intoxication does not usually cause high anion gap metabolic acidosis, but chronic alcohol use can cause ketoacidosis in malnourished patients. Ethanol abuse is a common predisposing factor for Mallory-Weiss tears; however, it is the repetitive vomiting and retching that directly cause the tears. (Choice C) Normal anion gap metabolic acidosis is usually caused by loss of bicarbonate, which can occur with prolonged diarrhea. Recurrent vomiting causes metabolic alkalosis, not acidosis. (Choices D and E) Respiratory acidosis usually occurs in patients with chronic obstructive pulmonary disease or central nervous system depression (eg, narcotic overdose). Respiratory alkalosis occurs with hyperventilation (eg, panic attacks, pulmonary emboli). Educational objective: A Mallory-Weiss tear is a tear in the gastric mucosa near the gastroesophageal junction. It typically results from repetitive forceful vomiting, which can also cause metabolic alkalosis. __________ References: Diagnosis and management of upper gastrointestinal bleeding. (http://www.ncbi.nlm.nih.gov/pubmed/19633792)

A 34-Year-Old Man with Upper Gastrointestinal Bleeding Is Brought to the Local