Key facts:
Authors: Kate Outterside, Sailesh Sankar, Ateeq Syed
Top Tip: Compared to DKA, HONK tends to affects older patients and its mortality is high
Key Differential Diagnoses
- DKA
- Hyperglycaemia, and other causes hypernatraemia or reduced conscious level
Key Investigations
- Glucose (BM)
- FBC, ESR, CRP
- U+E, LFT, Bone, Glucose, HbA1C ± Troponin T
- ABG, BC
- ECG, CXR
- Urinalysis ± MSU
Key Treatment
- IV + FLUIDS
- INSULIN (ACTRAPID, 50 units in 50 mls N saline), start infusion at 0.1 units/kg/hr
- SC ENOXAPARIN 40 mg od
Key Management Decision
- ITU
Background
Introduction
- Compared to DKA, HONK tends to affects older patients and its mortality is high
- In 60% it is the first presentation of diabetes (usually Type 2)
- Whereas only 10-20% of DKAs are first presentation of Type 1 (rest are patients known to have Type 1)
- Fluid resuscitation should be gentler, even though the fluid deficit is usually higher. A CVP line should be considered
- Sodium tends to be high. If the sodium is very high (>160), consider 0.45% saline (otherwise there is a risk of cerebral oedema due to over hydration)
- Glucose can be very high (>40 vs 10-30 mmol/L in DKA) but a gentler insulin regime should be used
Definition
- Condition characterised by severe hyperglycemia, hyperosmolarity (hypernatraemia) and dehydration in the absence of significant ketoacidosis
Aetiology
- Type 2 DM (60% first presentation of Type 2 DM)
- Elderly
- Genetic/racial (more common in Black/Asian people)
- Obesity
Precipitants
- MI
- Infection
- CVA
- Abdominal catastrophe (eg mesenteric ischaemia, acute pancreatitis)
Symptoms
- Non-specific
- Of precipitant
Note: can present as CVA, for eg
Key Question
- "Have you had an infection (or chest pain) recently?"
Signs
- Dehydration
- Reduced level of consciousness
- Seizures
Investigation
Glucose level is a guide to severity (in contrast to DKA). Unlike DKA, subsequent insulin therapy is not always necessary. Indeed some patients do well on hypoglycaemic agents and diet, or diet alone
Blood
- Glucose (BM); ± there is a separate Capillary Blood Strip for ketones, if the urinalysis is equivocal, and you are not sure whether HONK, or DKA
- FBC, ESR, CRP
- U+E, LFT, Bone, Glucose, HbA1C
Note: BG = >40 mmol/L; ie can be very high; much higher than DKA (10-30 mmol/L) - ± Troponin T (if abnormal ECG)
- BC, ABG; pH 7.35-7.45 (vs < 7.3 in DKA)
- Serum bicarbonate > 15 (vs < 15 in DKA)
Note: can be acidotic for non-DKA reasons; eg coexistent lactic acidosis; this worsens prognosis++
Other
- Urinalysis: ketones 1+ or less
- ± MSU (infection?)
- ECG (silent MI?)
- CXR (infection?)
Key investigations
- ABG
- Glucos(BM)
- Osmolality
- To establish a diagnosis:
Glucose: >40 mmol/L; plasma osmolality >350 mOsmol/kg; bicarbonate > 15 mmol/L; ketonuria 1+ or less, reduced conscious level
Specialist investigation
- Serum osmolality: increased osmolarity >350 mOsmol/kg
Note: measure it or calculate it
= 2([Na + K] + [Urea] + [ Glucose])
Differential diagnoses
- DKA
- Hyperglycaemia and causes hypernatraemia or reduced level of onsciousness
Treatment
Treatment (first line)
Drugs
- INSULIN (ACTRAPID, 50 units in 50 mls N saline, start infusion at 0.1 units/kg/hr; see DKA
Note: unlike DKA, subsequent insulin therapy not always necessary; may do well on hypoglycaemia agents and diet, or diet alone - SC ENOXAPARIN 40 mg od
- ± BROAD SPECTRUM AB (according to local policy), if infected
Procedures
- BM (hourly), lab bloods every 4h
- NG tube, if drowsy (prevent aspiration)
- IV (+ FLUIDS); fluid replacement on basis of clinical state and associated CV morbidity
Note: if Na > 160 mmol/L, give 0.45% saline, otherwise there is a risk of cerebral oedema due to over hydration; the Na level can be artificially high, and appear to go up, as glucose falls - OXYGEN, if hypoxic on air
Key management decision
- ITU/not
Treatment (second line)
Drugs
- If cerebral oedema, IV MANNITOL 0.25-2 g over 30-60 mins (usually 100 mls 20%), if cerebral oedema; repeated 1-2x after 4-8 hrs
Procedures
- If unwell, urinary catheter, CVP line (more useful than in DKA), arterial line
Prescribing issues
- Watch for cerebral oedema, if have given a lot of IV fluids
Admit?
- Yes
Bed plan
- Medical admission ward
- ± Endocrine
- ± ITU
Referrals
Medical
- Endocrine
- ± ITU
Other
- DM nurse (± community DM nurse)
The Rest
Watch for cerebral oedema, if over hydrate (especially if N Saline given too fast, and Na very high). If occurs, give mannitol/dexamethasone
Complications
- Arterial/venous thromboses
- Of infection
- Cerebral oedema, due to over hydration (if give N Saline too fast, and Na very high; if occurs, give mannitol/dexamethasone)
Follow-up
- Hospital DM nurse
- ± Community DM nurse + GP
Prognosis
- 50% mortality (vs 2-5 % in younger patients with DKA), partly because of the higher risk of arterial/venous thromboses
- Worse if BG very high, or co-existent lactic acidosis
2° Prevention + Health promotion
- Education
- Seek help, if BG > 20 mmol/L
- Or cannot give (or run out of) insulin or hypoglycaemic agents
Don't forget
- If sodium is very high (>160), give 0.45% IV saline
Red flags
- Reduced conscious level
- Severe sepsis/shock
- Severe acidosis (pH <7.1); ie HONK not cause
Note: if so, manage on ITU
