Final answer:
A 30-year-old female with polydipsia and polyuria, high blood glucose, and slightly lowered bicarbonate and normal pH levels is likely experiencing Hyperosmolar Hyperglycemic Nonketotic Syndrome (HHNS). Treatment involves fluids and insulin, with careful electrolyte management. Rapid changes in mental status might indicate cerebral edema, necessitating immediate medical attention.
Step-by-step explanation:
The diagnosis for a 30-year-old female presenting with a 3-day history of polydipsia and polyuria, a blood glucose level of 650 mg/dl, bicarbonate level of 21, and pH of 7.35 is Hyperosmolar Hyperglycemic Nonketotic Syndrome (HHNS). If this were Diabetic Ketoacidosis (DKA), the pH would indeed be much lower, reflecting a more acidic state due to the presence of ketone bodies, which are not typically found in high levels in HHNS.
The pathophysiology behind HHNS includes stress leading to increased cortisol levels, which in turn lead to increased blood glucose levels. Elevated glucose levels cause an osmotic diuresis, resulting in polyuria, and the patient's consequent dehydration leads to polydipsia.
Treatment for HHNS involves the administration of fluids and insulin to correct the hyperglycemia and dehydration. Monitoring electrolyte balance is crucial; sodium is usually low due to hyperosmolar hyponatremia. Potassium balance must also be assessed because even though serum potassium might appear high or normal due to the dehydration, the total body potassium is often low. Thus, potassium replacement is necessary.
If the patient becomes altered or comatose with rapid treatment, it could indicate cerebral edema, a serious and potentially life-threatening complication that can occur with aggressive correction of hyperglycemia.