HHS Flashcards
1
Q
What are the characteristics of HHS?
A
- Hypovolaemia
- Hyperglycaemia (> 30 mmol/L)
- Mild or absent ketonaemia (blood ketones < 3 mmol/L)
- High osmolality (> 320 mOsm/kg)
2
Q
What pts normally will get HHS?
A
- elderly with multiple comorbidities
- T2DM
3
Q
A
4
Q
What is the pathophysiology of HHS?
A
-
Relative lack of insulin
- prevents inhibition of ketogenesis
- but not enough to prevent hyperglycaemia
-
Rise in counter-regulatory hormones (e.g. cortisol, growth hormone, glucagon)
- Increase gluconeogenesis
- Increase glycogenolysis
-
1+2 = Hyperglycaemia
- proximal tubules reach max capacity for reabsorption of glucose
- remaining glucose is passed through the renal nephron
- osmotic diuresis occurs
5
Q
How many litres of fluid can HHS pt loss?
A
- 9L
6
Q
What are pt with HHS at risk of?
A
- Stroke
- DVT
7
Q
What are the causes of HHS?
A
- Infection
- High-dose steroids
- Myocardial infarction
- Vomiting
- Stroke
- Poor treatment concordance
8
Q
What are the clinical features of HHS?
A
- Polydipsia
- Polyuria
- Nausea
- Vomiting
- Muscle cramps
- Weakness
- Altered mental status
- Seizures
- Coma
- Dehydration (dry mucous membranes, sunken eyes, reduced capillary refill, decreased skin turgor)
- Hypotension
- Decreased urine output
- Decreased conscious level
- Coma
- Focal neurology signs
- Features of the precipitating cause
9
Q
What Ix would you order for HHS?
A
-
Bedside tests
- ECG
- Urinalysis +/- MSU
- Urinary pregnancy test
-
Blood tests
- FBC
- U&Es
- CRP
- LFTs
- Blood cultures
- Troponin
- Amylase
- CK
-
Imaging
- Chest X-ray
- CT head (if reduced GCS or focal neurology)
10
Q
Pt with HHS may require HDU if severe. What are the features to look for?
A
When 1 or more are present:
- osmolality >350 mosmol/kg
- sodium >160 mmol/L
- venous ⁄ arterial pH below 7.1
- hypokalaemia (less than 3.5 mmol/L) or hyperkalaemia (greater than 6 mmol/L) on admission
- Glasgow Coma Scale (GCS) less than 12 or abnormal
- AVPU (Alert, Voice, Pain, Unresponsive) scale
- oxygen saturation below 92% on air
- systolic blood pressure below 90 mmHg
- pulse over 100 or below 60 bpm
- urine output less than 0.5 ml/kg/hr
- serum creatinine >200 µmol/L
- hypothermia
- macrovascular event such as myocardial infarction or stroke
- other serious co-morbidity.
11
Q
What are the goals for HHS Mx?
A
- Normalise osmolality
- replace loss fluid and electrolyte
- normalise blood glucose
12
Q
What is the initial mx for HHS?
A
A-E assessment with
- Intravenous access (x2 large bore cannula)
- Blood / urinary ketones
- Capillary & plasma blood glucose
- FBC, U&Es, venous blood gas, plasma osmolality
- Blood cultures
- Urinalysis +/- MSU, Pregnancy test (as indicated)
- ECG
- CXR
- Urinary catheter
- Additional tests as indicated by the presentation/investigations (e.g. troponin, CT head)
13
Q
What is the fluid regimen like for HHS?
A
-
First hr:
- 0.9% saline solution. 1L in 1hr (quicker if hypotensive)
-
Second-sixth hr:
- 0.9% normal saline 0.5 – 1 L/hr
- Target; 2-3 litres positive by 6 hours
-
6-12 hr:
- Target: 3-6 litres positive by 12 hours
-
12-24 hr:
- Continue fluid
14
Q
What is the electrolyte replacement like in HHS?
A
- monitor Na, K, Ph, Mg every 4hrs
- General rule for K:
- Serum K+ > 5.5 mmol/L: Nil potassium replacement
- Serum K+ 3.5-5.5 mmol/L: 40 mmol potassium replacement
- Serum K+ < 3.5 mmol/L: Senior review for more invasive potassium replacement
15
Q
What is the insulin therapy like for HHS?
A
- commenced if there is evidence of
- significant ketonaemia (> 1 mmol/L) or
- ketonuria (2+ or more
- fixed rate intravenous insulin infusion (FRIII) at 0.05 units/kg/hr (half the dose used in DKA)
- Blood glucose maintained between 10-15 mmol/L in the first 24 hours
- 5% or 10% dextrose if levels fall < 14 mmol/L.
