Hyperosomolar hyperglycaemic state Flashcards
Pathophysiology
Hyperglycaemia results in osmotic diuresis with associated loss of sodium and potassium
Sever volume depletion results in significant raised serum osmolality so hyperviscosity of blood
Despite severe electrolyte losses and total body depletion, typical patient with HHS may not look as dehydrated as they are because hypertonicity leads to preservation of intravascular volume
Clinical features
General: fatigue, lethargy, nausea, vomiting
Neuro: altered consciousness, headaches, papilloedema, weakness
Haematological: hyperviscosity (may result in MI, stroke, peripheral arterial thrombosis)
CVD: drhydration, hypotension, tachycardia
Diagnosis
Hypovolaemia
Marked hyperglycaemia (>30mmol/L) without significant ketonaemia or acidosis
Significantly raised serum osmolality (>320mosmol/kg)
Management
Gradually normalise osmolality (serum osmolality key parameter)
Replace fluid and electrolyte losses
Gradually normalise blood glucose
Fluid losses
Estimated to be between 100-220ml/kg
Fluid replacement
IV 0.9% NaCl first line
Already relatively hypotonic compared to serum in someone with HHS
If serum osmolality not declining switch to 0.45% NaCl (more hypotonic compared to serum osmolality)
Aim of treatment
Replace approximately 50% estimated fluid loss within first 12 hours and remaining in the following 12 hours
Monitoring response
Key parameter is serum osmolality (glucose and sodium are main contributors)
Rapid change can cause CVD collapse and central pontine myelinolysis
Target blood glucose
Between 10-15mmol/L
Insulin
Fluid replacement alone will result in gradual decline of blood glucose and osmolarity
Insulin can result in rapid decline of serum glucose and osmolarity
Prior to fluid replacement may cause CVD collapse and CPM
Only use if significant ketonaemia (fixed rate IV insulin at 0.05 units/kg/hour)
Potassium
Patients potassium deplete but less acidotic than DKA so potassium shift less pronounced
Hyperkalaemia may present with AKI
Patients on diuretics may be profoundly hypokalaemic
Potassium should be replaced or omitted as required