Diabetic Ketoacidosis l: Introduction

Diabetic ketoacidosis results from insulin deficiency combined with elevated counterregulatory hormones including glucagon, catecholamines, cortisol, and growth hormone. This hormonal imbalance increases lipolysis and hepatic ketone production while impairing glucose utilization, leading to the characteristic triad of hyperglycemia, ketonemia, and metabolic acidosis.

DKA severity is classified into three categories based on blood pH and bicarbonate levels. Mild DKA has pH 7.25-7.30 and bicarbonate 15-18 mEq/L. Moderate DKA shows pH 7.00-7.24 and bicarbonate 10-15 mEq/L. Severe DKA presents with pH below 7.00 and bicarbonate below 10 mEq/L, guiding treatment intensity and monitoring requirements.

Early symptoms of diabetic ketoacidosis include polyuria, polydipsia, and nocturia, reflecting osmotic diuresis from hyperglycemia. These signs typically develop within 24 hours in type 1 diabetics lacking sufficient insulin. As dehydration progresses, patients may experience dry mucous membranes, hypotension, and tachycardia.

As DKA progresses, patients develop nausea, vomiting, and abdominal pain that typically resolve with acidosis correction. Respiratory compensation manifests as Kussmaul respirations—deep, rapid breathing in response to metabolic acidosis. A fruity odor on the breath, caused by acetone, is a classic clinical indicator of ketone production.

Neurological symptoms such as lethargy, confusion, and coma occur in advanced DKA cases, particularly when serum osmolality exceeds 330 mOsm/kg. These severe manifestations indicate significant metabolic derangement and require urgent intervention. DKA may also present as the initial manifestation of previously undiagnosed type 1 diabetes.

In type 1 diabetics with insufficient insulin, diabetic ketoacidosis can develop within 24 hours. The acute onset reflects the rapid accumulation of ketone bodies and hydrogen ions, overwhelming the body's buffering capacity. Early recognition of initial symptoms like polyuria and polydipsia is critical for preventing progression to severe acidosis.

Diabetic ketoacidosis is characterized by three diagnostic features: hyperglycemia with blood glucose exceeding 250 mg/dL, ketonemia or ketonuria indicating ketone body accumulation, and metabolic acidosis with arterial pH below 7.30 and serum bicarbonate below 18 mEq/L. This triad distinguishes DKA from other acute diabetic emergencies.