Altered Conscious Level
80 General Medical Emergencies
(i) It may be considered if the pH remains <7.0, particularly with
circulatory failure.Hyperglycaemic, hyperosmolar non-ketotic syndrome
DIAGNOSIS
1 HHNS is more common in the elderly, non-insulin-dependent patient, with
a more gradual onset than DKA.
2 It may be precipitated by infection, myocardial infarction, a stroke or by
thiazide diuretic use and steroids, and like DKA, may occur in a previously
undiagnosed patient.
3 The patient presents with an altered level of consciousness, profound
dehydration and may develop seizures or focal neurological signs. Mortality
is 20–40%, compared to DKA where it is <5% in younger patients.
4 Blood glucose and serum osmolarity tend to be higher than in DKA. The
osmolarity usually exceeds 350 mOsmol/L.
(i) Estimate the osmolarity by 2(Na + K) + urea + glucose (all units
in mmol/L).
5 Make certain to do an ECG, CXR and an MSU early.MANAGEMENT
1 This is comparable to DKA (see above).
2 Give i.v. normal saline or half-normal saline if the serum sodium exceeds
150 mmol/L, at a similar or slower rate to DKA. Beware of over-rapid
rehydration causing pulmonary oedema.
3 Use a slower insulin infusion rate of 0.05 units/kg per hour, i.e. 2–3 units/h,
as there is increased insulin sensitivity compared to DKA. Lower potassium
replacement rates are also usual.
4 Commence prophylactic heparin, either unfractionated (UF) heparin 5000
units i.v. bolus then an infusion at 1000 units/h, or LMW heparin such as
enoxaparin 1.5 mg/kg per day, assuming there is no active bleeding, particu-
larly intracerebral.
5 Admit under the care of the medical team.ALTERED CONSCIOUS LEVEL
Patients with an altered conscious level frequently present to the ED. Although
history taking is compromised, a methodical, careful approach is essential using
information from the family, friends, passers-by, the police, ambulance and
previous medical records.