Diabetes

Question 1

A 19-year-old man presents to the emergency department with abdominal pain and fatigue for the past 24 hours. For the past two days, the patient has had poor appetite, increased thirst, and frequent urination. On further questioning, the patient mentions that he has no dysuria but has been having difficulty breathing for the past several hours. Past medical history is unremarkable. Temperature is 37.0 °C (98.6 °F), pulse is 108/min, blood pressure is 100/65, respiratory rate is 22/min, and oxygen saturation (SpOz) is 99% on room air. On physical examination, the patient is fatigued. Mucous membranes appear dry. The lungs are clear to auscultation. The abdomen is soft and nontender to palpation. The patient’s posterior calves are tender to palpation bilaterally. Serum bicarbonate is 12 mEq/L and creatinine is 1.7 mg/dL. Urinalysis shows 3-5 WBC/hpf and no bacteria. Chest x-ray is unremarkable. What should be ordered next?

Answer 1

This young patient with fatigue, nonspecific abdominal pain, increased thirst, and frequent urination has symptoms suggestive of undiagnosed diabetes mellitus and severe hyperglycemia. Physical examination finding of dry mucous membranes and hypotension suggests severe dehydration. Low serum bicarbonate indicates metabolic acidosis that could be secondary to diabetic ketoacidosis in this setting. This patient should be aggressively resuscitated with intravenous 0.9% saline. The diagnostic approach in patients with acute dyspnea should be systematic. In hemodynamically stable patients, focused history and physical examination should be performed. Pulmonary causes of dyspnea generally present with abnormal lung sounds and often hypoxemia. Diffusely decreased or abnormal breath sounds with wheezing can be seen in asthma and COPD exacerbations. Patients with COPD may have hyperinflated lungs on chest imaging and chronic metabolic alkalosis on laboratory testing. Localized decreased or abnormal breath sounds may indicate pneumothorax or pneumonia, and chest imaging can differentiate between the two. Pneumonia will generally have associated fever and leukocytosis, with focal consolidations or diffuse infiltrates on imaging. Cardiovascular causes (e.g. heart failure) will usually present with signs of volume overload such as jugular venous distention, pulmonary crackles and peripheral edema. Electrocardiogram may show arrhythmia, ischemic changes (e.g. ST segment elevation) or specific findings such as electrical alternans (in cardiac tamponade) or S1Q3T3 (in pulmonary embolism). While pulmonary embolism often presents with dyspnea and chest pain, lungs will be clear to auscultation. Metabolic/Toxic causes should be suspected when cardiopulmonary exam and chest imaging are unremarkable. Oftentimes there is no associated hypoxemia in these cases. This patient likely has diabetic ketoacidosis. Severe metabolic acidosis has led to compensatory hyperventilation and dyspnea. Anxiety and panic disorder can also cause dyspnea and the rest of the workup will be negative. Neuromuscular causes, such as amyotrophic lateral sclerosis or Guillain-Barré syndrome, should also be ruled out in the appropriate clinical setting.