The patient’s clinical features—Type I diabetes, nausea, vomiting, altered sensorium, tachypnea, hypotension, hyperglycemia at 460 mg/dL, and ketonuria—are highly consistent with Diabetic Ketoacidosis (DKA). This condition is a medical emergency that requires a systematic approach for both diagnosis and treatment.

Diagnosis
Clinical assessment: Altered consciousness, dehydration, hypotension, and deep labored tachypnea (Kussmaul breathing) are typical.
Laboratory confirmation: Random blood glucose is 460 mg/dL, while urine ketones are strongly positive (++). Serum beta-hydroxybutyrate levels, if available, provide superior accuracy for monitoring. Arterial blood gas usually reveals metabolic acidosis with pH below 7.3 and bicarbonate under 18 mEq/L. Electrolytes must be measured to assess sodium, potassium, and anion gap. Renal function tests (BUN, creatinine) establish baseline status. Potential precipitating factors such as infection, myocardial infarction, trauma, or missed insulin doses should be actively investigated.

Management
Fluid resuscitation: First priority is restoring intravascular volume. Begin with 0.9% saline at 1 L/hour during the initial hour, then adjust based on hydration, urine output, and electrolyte balance. Rehydration improves perfusion, enhances insulin sensitivity, and helps reduce glucose.
Insulin therapy: Initiate continuous intravenous infusion of regular insulin at 0.1 units/kg/hour after fluids. This halts ketogenesis, corrects acidosis, and gradually lowers glucose. Blood glucose should be checked hourly to avoid rapid shifts.
Potassium replacement: Total body potassium is severely depleted despite possible initial hyperkalemia. Once serum potassium falls below 5.0 mEq/L with established urine output, potassium supplementation must be started to prevent life-threatening hypokalemia during insulin therapy.
Bicarbonate therapy: Considered only if pH is extremely low (<6.9).
Address precipitating factors: Treat infections promptly, ensure insulin compliance, and correct other triggers.
Transition to subcutaneous insulin: When glucose is <200 mg/dL, bicarbonate >18, pH >7.3, and the anion gap closes, begin subcutaneous insulin, overlapping IV insulin for 1–2 hours to avoid recurrence.

Continuous monitoring of vitals, electrolytes, acid–base status, and fluids is essential throughout therapy.