Diabetes for House Officers

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Transcript Diabetes for House Officers

Diabetic Emergencies
Emergency Block
DKA
DKA PATHOPHYSIOLOGY
• Severe insulin deficiency
• increased glucagon promotes lipolysis
• Results in a massive increase in ketogenesis
DIABETIC EMERGENCIES
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KETONES
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ACETOACETATE
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ACETONE
• β HYDROXY BUTYRATE
<1.5mmol/l
More than 3mmol/l in blood
Pathophysiology
Insulin deficiency and glucagon excess
↑ Blood ketones
Acidosis
Cellular dysfunction
↑ Blood glucose
Vomiting
Osmotic diuresis
Fluid and electrolyte disturbance
Cerebral oedema
Shock
Who gets DKA?
• Hallmark of type 1 diabetes
• Previously undiagnosed DM (about 25 –
30%)
• Interruption to normal insulin regime
• Intercurrent illness - usually infection
Symptoms and signs
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Nausea
Vomiting
Abdominal pain
Preceding polyuria, polydipsia, weight loss
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Drowsiness/confusion/coma
Kussmaul respiration - hyperventilation
‘Pear drops’ breath
Sign of infection or assoc disease _ (MI,
pancreatitis)
How do I diagnose DKA?
Diagnosis requires all 3 of the following:
• Ketonaemia 3 mmol/L and over or
significant ketonuria (more than 2+ on
standard urine sticks)
• Blood glucose over 11 mmol/L or known
diabetes mellitus
• Bicarbonate (HCO3- ) below 15 mmol/L
and/or venous pH less than 7.3
Investigations
• Bloods
– FBC, UE, HCO3, LFT, CRP, Glu, cultures, amylase,
cardiac enzymes, Blood ketones
• Urine
– Ketones, MSU
• ABG
– Initially only (lab HCO3 after)
• CXR
• ECG
Example ABG
pH
Patient 1
7.35
Patient 2
7.1
pCO2
3.2
2.1
pO2
16.0
9.1
HCO3
16.1
11.2
Treatment priorities
1.
2.
3.
4.
5.
Replace fluids
Replace electrolytes
Replace insulin
Look for cause
Close monitoring
Replacing fluids
Initial management
• 1L 0.9% NaCl
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30 mins
1hr
2hr
4 hr
Then continue NaCl
0.9% as dictated by
fluid status
Later
• Slow NaCl and run 5%
dextrose concurrently
when gluc <15mmol
• If gluc normal but still
ketones continue steady
insulin with 5% or 10%
dextrose (avoids recurrent
DKA)
Replace electrolytes
• K+ is most important
• Insulin shifts K+ into cells therefore K+ will fall
as rehydrate
• Consider adding K+ when serum K+ < 5.5
• Hyponatraemia may occur due to osmotic effect of
glucose - it will correct with treatment of DKA
Key Changes
• Fixed rate insulin infusion
– 0.1 u/kg/hr
– Even when near normoglycaemia attained
• Monitoring of capillary betahydroxybutyrate
– Diagnosis
– Monitoring adequacy of treatment
– Endpoint for completion of treatment
Monitoring
• Monitor urine output and vital signs closely
– catheterize
• Repeat U&E, glucose, venous bicarbonate –
ABG PAINFUL
• 2 – 4 hours, 6 - 8 hours, 12 hours, 24 hours
• Repeat ABG at 2 hours if not improving
• ? Alternative cause for acidosis e.g. lactate
What should we be expecting?
• Wallace et al 2001
– Ketones on presentation 3.9 – 12.33
– Median half life of beta-hydroxybutyrate was 1.64 hrs
– Suggested rate of ketone fall of 1 mmol/l/hr as indicator of
adequate treatment
The hospital and home use of a 30-second hand-held blood ketone meter: guidelines for clinical practice
T. M. Wallace, N. M. Meston*, S. G. Gardner² and D. R. Matthews
Diabetic Medicine, Volume 18, Issue 8 (p 640-645)
Suggestions
• Review if glucose not improving by 3-5
mmol/L/h or ketones by 0.5 – 1 mmol/L/h
1. First check hydration has been addressed
2. Check infusion equipment
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Lines
Pump
Solution
3. Increase rate of insulin infusion
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Unclear by how much
Some sources say double
Guidelines say increase by 1-2u/h
Cause of Vomiting and Abdominal
Pain
• Vomiting
– Excess ketone bodies causes vomiting
– Gastric atony due to electrolyte imbalance
• Abdominal pain
– Peritoneal dehydration
– Pancreatitits
What happens to the following in DKA?
Plasma
Magnesium
Phosphate
Chloride
Cholesterol
Triglycerides
Lipoprotein
Amylase
Total body
With treatment
Pitfalls
• Does a high wcc mean infection?
• No, not necessarily!
• Give antibiotics as guided by findings
• Absence of fever doesn’t mean absence of infection
• Consider alternative cause for acidosis if glucose
and acidosis markedly out of proportion
• Non specific abdo pain and raised amylase doesn’t
always mean pancreatitis
• Do not stop insulin even if the blood glucose is
normal or below 4
Discharge, Prognosis and Prevention
• How do you stop a sliding scale?
– Overlap with normal insulin (breakfast) and keep in for
an other 24 hours to monitor BMs
• Prevention
– Diabetic nurse + docs can use opportunity for patient
education about insulin regime etc.
• Mortality is < 5%
– Patients with frequent episodes are at increased risk of
dying and diabetic complications
HHS/HONK
• Hallmark of type 2 DM
• May occur in:
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New diagnosis
Poor compliance with treatment
Intercurrent illness – especially MI, Infection, CVA
Drugs- Steroids
Sugary drinks
Tissue glucose uptake
glycogenolysis
Hepatic glucose output
gluconeogenesis
proteolysis
Plasma amino acids
lipolysis
Plasma free fatty acids
hyperglycaemia
Plasma osmolality
Urea synthesis
ketogenesis
Glycosuria/ Osmotic diuresis
thirst
Loss of water Na & K +
hypovolaemia
Prerenal uraemia
GFR
vomiting
hyperventilation
Renal H+ excretion
ketonaemia
acidosis
Why is it different from DKA?
• Insulin production markedly reduced but NOT
absent.
• No switch to fat metabolism and therefore no
ketones or acidosis
• Mortality markedly higher
– Co-morbidities, longer time to diagnosis, electrolyte
disturbances
– Cerebral oedema and Pulmonary Embolism more
common
How do I recognise it?
• Diagnosis requires ALL of the following:
• Raised blood glucose (usually >30mmol)
• Absence of ketones (or + or ++ only)
• Serum osmolality >350mmol
How do you calculate
osmolality?
2(Na+K) + urea + glucose
Or
Ask for a serum level (U and E bottle,
biochemistry)
Clinical features
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Possibly osmotic symptoms
Dehydration around 10L deficit
decrease LOC
signs of underlying infection in upto 50%
+/- thrombo-embolism in up to 30%
2/3 cases previously undiagnosed
As high as 50% mortality
Is the treatment the same as DKA?
• Fluid replacement – SLOWER (may be
a marker of population not pathology)
• Electrolyte replacement
(pseudohyponatraemia)
• Insulin – ‘slower’ scale
• Search for cause
• ANTICOAGULATION
• Monitor
HYPOGLYCAEMIA
zero tolerance
• Definition: is a plasma glucose of<3mmol/l
• Requires immediate treatment
or
Low blood glucose level with symptom
complex
or
Requiring 3rd party rescue
Symptoms
• Fall in glucose triggers fixed hierarchy of events:
• 1) inhibition of insulin secretion
• 2) release of glucagon and adrenaline
(~3.8mmol/l)
• 3) hypoglycaemic symptoms (~3.0mmol/l)
All the above responses are diminished especially
Glucagon Response
Symptoms
• Autonomic
• sweating, palpitations, tremor,hunger
• Neuroglycopenia
– confusion, clumsiness, behavioural changes
• Non-specific
– nausea,headache
Aetiology
• Reactive Hypoglycaemia
– Post prandial
– gastric surgery
• Drug Induced
– insulin
– sulphonylureas
– alcohol
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Fasting
P- pituitary failure
L- liver disease
A- Addison
I - Islet cell tumours
N- neoplasmretroperitoneal fibro
sarcomas
Treatment of hypoglycaemia
• If able to eat
– glucose: e.g 3 dextrosol tabs / 200mls of orange juice/
coca cola
– followed by long acting carbohydrate eg toast/
sandwich
• In a semi-conscious patient
• In the community: 1mg glucagon im and
long acting carbohydrate on recovery
Severe Hypoglycaemia
• Consider in any unconscious patient, those
with CVA or odd behaviour
• Hospital options– I.M. glucagon 1mg
– I.V. 20% [50%*] dextrose (typically 50 ml)
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Other options- Hypostop gel
Look for precipitants/causes and avoid
Psychological consequences
Review oral hypoglycaemic drugs
Driving precautions and regaining
awareness
*Extravasation of 50% dextrose can cause severe tissue loss; 20% preferable
An example
A 39 year old man is brought in by his
wife. He is dehydrated and a little
confused. He is not known to be diabetic
but his BM on arrival is 25mmol.
Further information
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Serum glucose 24 mmol
Urine ketones ++
Blood gas - machine broken
Bicarbonate awaited
Is this DKA or HONK?
His wife is present. What questions might you ask
her to help you work out what is going on?
Diagnosing Diabetes
Stage
Fasting plasma
glucose
Normal
<6.1mmol/l
Impaired
Fasting
Glycaemia
≥ 6.1 and <7.0
Random plasma OGTT
glucose
2hr plasma
glucose
≥7.8 and <11.1
Impaired
Glucose
Tolerance
Diabetes
<7.8mmol/l
≥7.0 (2 readings) ≥11.1mmol/l
+Symptoms
>11.1mmol/l
Any questions about
diabetic
emergencies?