INVESTIGATIONS AND DIFFERENTIALS OF HYPERGLYCAEMIC EMERGENCIES ILERHUNMWUWA P.N (MBBS, Benin) Senior Registrar Endocrinology, Diabetes and Metabolism Unit

OUTLINE Investigations to confirm diagnosis and assess severity Ancillary investigations Investigations to establish precipitants Differentials

INVESTIGATIONS TO CONFIRM DIAGNOSIS AND ASSESS SEVERITY DKA(mild) DKA( moderate) DKA( severe) HHS Plasma glucose (mg/dl) 250 > 250 600 Urine ketones ++/+++ . May be negative. +/Absent Serum ketones * ++/+++ Serum osmolarity (mOsm/L) Serum Osmolarity (in mOsm/L) = 2[Na++K] + plasma glucose + plasma urea Normal Serum Osmolarity = 275 -300 mOsmol/L Variable > 320

……contd DKA(mild) DKA(moderate) DKA(severe) HHS Anion gap = (Na++K+) – (HCO3-+Cl-) Normal anion gap = 10–12 mmol/L > 10. Typically above 14 > 12. Typically above 14 > 12 Variable. Typically normal. Serum bicarbonate (mEq/L)* Normal value = 22 - 30 15 - 18 10 - 15 < 10 > 15 Arterial pH * Normal arterial pH = 7.35-7.45 7.25 – 7.30 7.00 – 7.24 < 7.00 > 7.30 * Used to assess severity

ANCILIARY INVESTIGATIONS Comments Full blood count with differentials Anemia, leukocytosis typical and does not indicate infection Leukocyte counts commonly between 10000 to 15000 cells per uL Leukocyte counts above 25000 suggests infection Peripheral blood fiml important to establish infection Electrolytes, urea and creatinine Serum sodium typically low or near-normal in DKA but high in HHS Serum potassium may be elevated, normal or low. Azotemia may result from dehydration, or indicate renal failure as the precipitant. Fasting lipid profile Hypertriglyceridemia may account for pseudohypnatraemia and pseudonormoglycaemias Serum lactate Could be elevated in DKA In the presence of normal plasma glucose, strongly suggests lactic acidosis.

INVESTIGATIONS TO ESTABLISH PRECIPITANTS Urine m/c/s Sputum m/c/s Blood culture Cardiac enzymes ECG Chest x-ray Brain imaging Thyroid function tests Toxicology screening

DIFFERENTIAL DIAGNOSES 1. Other causes of acute abdomen e.g acute pancreatitis, peptic ulcer disease 2. Other causes of altered sensorium e.g meningitis, cerebral malaria 3. Other causes of ketosis e.g starvation, alcohol ingestion 4. Other causes of high-anion gap metabolic acidosis e.g lactic acidosis

SUMMARY Investigations are needed to establish the type of hyperglycaemic emergencies as this will ultimately influence the line of management. It is very important to establish the precipitant as failure to do this may result in poor response to treatment. There are many conditions that can mimic the presentation of hyperglycaemic emergencies and these must be sought for in the history and consequently investigations.

REFERENCES Diabetes Care. 2009; 32(7): 1335- 1343. Slovis CM, Mork VG, Slovis RJ, et al. Diabetic ketoacidosis and infection: leukocyte count and differential as early predictors of serious infection. Am J Emerg Med 1987; 5: 1-5. Sheikh-Ali M, Karon BS, Basu A, et al. Can serum beta- hydroxybutyrate be used to diagnose diabetic ketoacidosis? Diabetes Care 2008; 31: 643-647.