A 68-year-old man is brought to the emergency department by his daughter due to confusion and lethargy. The patient's daughter reports that he lives alone and has type 2 diabetes mellitus and hypertension. He takes aspirin, enalapril, and glipizide. He is afebrile. Blood pressure is 99/59 mm Hg, pulse is 132/min, and respirations are 22/min. The patient appears drowsy and is barely communicative. Examination shows dry mucous membranes, absent jugular venous distention, clear lung fields, and normal heart sounds. The abdomen is soft, nontender, and nondistended. Neurologic examination shows disorientation to time and place. The patient moves all extremities and examination shows no meningeal signs. Laboratory results are as follows: An ECG shows atrial fibrillation with a rapid ventricular response. Nonspecific T wave changes are present. Which of the following is the best initial approach to managing this patient?

Question

A 68-year-old man is brought to the emergency department by his daughter due to confusion and lethargy.  The patient's daughter reports that he lives alone and has type 2 diabetes mellitus and hypertension.  He takes aspirin, enalapril, and glipizide.  He is afebrile.  Blood pressure is 99/59 mm Hg, pulse is 132/min, and respirations are 22/min.  The patient appears drowsy and is barely communicative.  Examination shows dry mucous membranes, absent jugular venous distention, clear lung fields, and normal heart sounds.  The abdomen is soft, nontender, and nondistended.  Neurologic examination shows disorientation to time and place.  The patient moves all extremities and examination shows no meningeal signs.  Laboratory results are as follows:  An ECG shows atrial fibrillation with a rapid ventricular response.  Nonspecific T wave changes are present.  Which of the following is the best initial approach to managing this patient?

Quizplus · Accepted Answer

Explanation: This patient's clinical presentation and markedly elevated glucose are consistent with a hyperosmolar hyperglycemic state (HHS). Both HHS and diabetic ketoacidosis (DKA) occur in patients with poorly controlled diabetes. Patients with type 2 diabetes mellitus tend to develop HHS as opposed to DKA, which is ruled out in this patient by negative serum ketones. In patients with HHS, the serum bicarbonate is generally near the lower limits of normal (as seen in this patient); in contrast, those with DKA frequently have an anion gap acidosis (due to ketoacid production). In HHS, dehydration (evidenced by this patient's dry mucous membranes and tachycardia) occurs from an osmotic diuresis caused by hyperglycemia. In addition, this patient likely has a mild acute renal failure, although comparison with a baseline creatinine is necessary. In HHS, neurologic symptoms ensue because of markedly increased serum osmolality. Sodium levels can be decreased or increased in patients with HHS; this patient's hypernatremia is likely exacerbating his altered mental status. Patients with HHS are frequently hyperkalemic due to a relative insulin insufficiency and hyperosmolality; this is in spite of an overall body potassium deficit caused by increased urinary excretion. The first step in the management of HHS is aggressive fluid resuscitation (typically with isotonic saline), as these patients frequently have had a fluid loss of 8-10 liters. (Choice A) Aggressive reduction of serum potassium level should be avoided in patients with HHS who are hyperkalemic. These patients have an overall potassium deficiency that would become unmasked with fluids and insulin. Potassium supplementation is frequently necessary when the serum level falls below 5.3 mEq/L. (Choice B) Rapid lowering of blood glucose with insulin can be harmful since it creates an osmotic gradient between the central nervous system and intravascular space. Instead the focus should be on vigorous fluid resuscitation. Intravenous insulin should be started after the patient has been partially resuscitated (2-3 liters). (Choice C) This patient's atrial fibrillation is likely secondary to stress from a HHS. Treatment with rate control agents such as beta blockers or calcium channel blockers would be needed eventually, but aggressive fluid resuscitation should be the first priority. This patient's somewhat low blood pressure makes it a challenge to use these medications. Volume resuscitation will improve both the hypotension and the tachycardia. (Choice D) In atrial fibrillation rate control is as effective as rhythm control. This patient's rhythm will likely revert back to sinus rhythm once the stress of his HHS has been resolved; therefore rhythm control medications are unnecessary at this time. Educational objective: Aggressive volume resuscitation is necessary in patients with a hyperosmolar hyperglycemic state (HHS), since they are generally severely volume depleted. Intravenous insulin should be started after the patient has been partially resuscitated. Aggressive management of hyperkalemia should be avoided in these patients since these patients generally have a total body potassium deficit. References: Physiopathology and management of hyperosmolar hyperglycemic nonketotic dehydration. (http://www.ncbi.nlm.nih.gov/pubmed/6801794) Hyperosmolar hyperglycemic state. (http://www.ncbi.nlm.nih.gov/pubmed/15887451)

A 68-Year-Old Man Is Brought to the Emergency Department by His