Diabetic Emergencies Emergency Block. DKA DKA PATHOPHYSIOLOGY Severe insulin deficiency increased...
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Transcript of Diabetic Emergencies Emergency Block. DKA DKA PATHOPHYSIOLOGY Severe insulin deficiency increased...
DKADKA PATHOPHYSIOLOGY
• Severe insulin deficiency
• increased glucagon promotes lipolysis
• Results in a massive increase in ketogenesis
DIABETIC EMERGENCIES
• KETONES
• ACETOACETATE
• ACETONE
• β HYDROXY BUTYRATE
<1.5mmol/l
More than 3mmol/l in blood
Pathophysiology
Insulin deficiency and glucagon excess
↑ Blood ketones ↑ Blood glucose
Acidosis Osmotic diuresis
Fluid and electrolyte disturbance
Cerebral oedema Shock
Vomiting
Cellular dysfunction
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
• Nausea• Vomiting• Abdominal pain• Preceding polyuria, polydipsia, weight loss
• 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
Treatment priorities
1. Replace fluids
2. Replace electrolytes
3. Replace insulin
4. Look for cause
5. Close monitoring
Replacing fluids
Initial management
• 1L 0.9% NaCl • 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 beta-hydroxybutyrate– 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 practiceT. M. Wallace, N. M. Meston*, S. G. Gardner² and D. R. MatthewsDiabetic 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 addressed2. Check infusion equipment
• Lines• Pump• Solution
3. Increase rate of insulin infusion• 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 Total body
Magnesium
Phosphate
Chloride
Cholesterol
Triglycerides
Lipoprotein
Amylase
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:• New diagnosis
• Poor compliance with treatment
• Intercurrent illness – especially MI, Infection, CVA
• Drugs- Steroids
• Sugary drinks
glycogenolysis gluconeogenesis proteolysis lipolysis Tissue glucose uptake
Plasma amino acidsPlasma free fatty acids
ketogenesis
ketonaemia
acidosis
Urea synthesis
vomiting
hyperventilation
Renal H+ excretion GFR
hypovolaemia
Loss of water Na & K +
Plasma osmolality
thirst
Glycosuria/ Osmotic diuresis
hyperglycaemia
Hepatic glucose output
Prerenal uraemia
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
• 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
HYPOGLYCAEMIAzero 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
Fasting• P- pituitary failure• L- liver disease• A- Addison• I - Islet cell tumours• N- neoplasm-
retroperitoneal 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)
• 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
• 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 DiabetesStage Fasting plasma
glucose Random plasma glucose
OGTT
2hr plasma glucose
Normal <6.1mmol/l <7.8mmol/l
Impaired Fasting
Glycaemia
≥ 6.1 and <7.0
Impaired Glucose
Tolerance
≥7.8 and <11.1
Diabetes ≥7.0 (2 readings) ≥11.1mmol/l
+Symptoms
>11.1mmol/l