Small animal endocrinopathies 3 Flashcards
Ketoacidosis
What findings may be expected on haematology in ketoacidosis?
- May be normal or stress leukogram
- Mature neutrophilia
- Left shift indicative of infection
- Heinz bodies in cats
Why might hypokalaemia occur in ketoacidosis?
Chronic PUPD = renal loss of K
Inadequate intake due to anorexia, GI losses due to V/D, insulin treatment drives potassium into cells
Why might hyperkalaemia occur in ketoacidosis?
- May move into extracellular location secondary to acidosis/lack of insulin/plasma hyperosmolarity
- Could reflect decreased urine output secondary to oluguric or anuric renal failure
What might urinalysis show in DKA?
- Dipstick shows acetone and acetoacetate (NB main one is BHB)
- Glucosuria, ketonuria
- Elevated USG
- Evidence of UTI
What management is required for a bright, happy ketonuric diabetic?
Does not need to be managed as a DKA - simply normal diabetic treatment
What factors need to be corrected in a DKA?
- Fluid deficits
- Perfusion
- Electrolyte abnormaliites
- Acidosis (via restoration of perfusion)
- Insulin and glucose
Outline the fluid therapy in a DKA
- Saline/Hartmann’s, IV
- Fluid bolus indicated
- Account for ongoing losses
- Monitor HR, pulse rate and peripheral pulse quality, RR and effort/crackles on ausc, MM colour and CRT, renal function via urine output
What are the signs of fluid overload?
- Shivering
- Nausea
- Vomiting
- Restlessness
- Tachypnoea
- Coughing
- Chemosis
What bolus of isotonic crystalloid fluids should be given in mild hypovolaemia?
10-20ml/kg over 30min to 1hr
What bolus of isotonic crystalloid fluids should be given in moderate hypovolaemia?
20-40ml/kg over 30 min to 1 hour
What bolus of isotonic crystalloid fluids should be given in marked hypovolaemia?
40-60ml/kg over 15 min to 1 hour
What degree of hypovolaemia would these clinical parameters suggest in a dog? HR: 130-150 MM: normal-pink CRT: rapid (<1s) Pulse amplitude: increased Metatarsal pulse: easily palpable
Mild hypovoalemia
What degree of hypovolaemia would these clinical parameters suggest in a dog? HR: 170-220 MM: grey, white or muddy CRT: prologed (>2s) Pulse amplitude: severely decreased Metatarsal pulse: absent
Severe
What degree of hypovolaemia would these clinical parameters suggest in a dog?
HR: 150-170
MM: pale pink
CRT: normal
Pulse amplitude: mild to moderate decreased
Metatarsal pulse: just palpable
Moderate
In what situation in a DKA crisis would fluid loss need to be corrected more rapidly?
PUPD, V/D, esp. if there is pre-ranl axotaemia
Once hypovolaemia in DKA crisis has been addressed, what fluid therapy is required?
Need to replace fluid deficit i.e % dehydration, replace in 12-24 hrs, sometimes replace half of deficit in first 4-6 hours. Need to also replace ongoing losses based on monitoring
What electrolyte may need to be supplemented in a DKA crisis and why?
Potassium - restoring renal perfusion leads to decreased serum K due to increased excretion, and correcting acidosis favours return of K+ into cells, as does insulin treatment
How should potassium be corrected in DKA crisis?
Supplement potassium in fluids
Explain the use of insulin in the treatment of DKA
- Rapid acting essential, “neutral” or “regular” for IV use
- Lots of protocols available
- No licensed animal preparation so use human
Give an example of an insulin protocol in the treatment of DKA
1: CRI soluble insulin. Add 25IU neutral insulin to 500ml bag 0.9% NaCl OR 2.5IU to a 50ml syringe. Infuse at 1ml/kg/hr until BG <15mmol/l. Then reduce insulin infusion rate to 0.5ml/kg/hr. Requires 2 bags 0 one for insulin and 1 for fluids +/- potassium (run at v different rates)
2: Initial dose 0.2IU/kg soluble insulin IM followed by 0.1IU/kg IM every 1 hour until BG <15mmol/l. Then 0.5IU/kg soluble insulin SC with subsequent adjusted doses q6h
What is required when using insulin in the treatment of DKA and why?
Carbohydrate source, exogenous insulin admin presents risk of hypoglycaemia (BG falls long before ketoacidosis resolves), animal may also be slow to start eating due to underlying trigger disease
Outline the provision of carbohydrate source in the treatment of DKA
- Supplementation of fluids with dextrose start when BG <15mmol/l (and reduce insulin), srtart 2.5% glucose infusion at 6-7ml/kg/hr
- Small vols of low fat food
What treatment is required once the BG is controlled in DKA and no further vomiting?
Start insulin therapy with longer acting insulin preparation e.g. Caninsulin
Other than fluids, insulin, potassium and CHO, what other treatments are indicated in DKA?
- treat underlying disease
- Analgesia (e.g. in pancreatitis esp., pain => inappetance)
- Anti-emetics (reduce fluid loss, encourage eating)
- Antibiotics (if awaiting culture and suspicious of UTI, also high risk of secondary infection)
What monitoring is required following a DKA?
- BG q1-2 hours
- K+ q4-6hrs
- Urine ketones
- PCV/total solids daily (dehydration status assessment)
What general conditions could the following clinical signs be indicative of in a puppy?
Mental dullness progressing to collapse, tachycardia, tremors, vocalisation, paresis/paralysis
- Neurological condition
- Hypoglycaemia
- Intoxication
- Liver disease
- Polycythermia
- Portosystemic shunt
- Dehydration
- Hypothermia
- Hypoadrenocorticism
- Parvo (and other infectious diseases)
At what BG level do clinical signs of hypoglycaemia usually occur?
2.5mmol/L
What are the potential consequences of hypoglycaemia?
- Neuronal damage
- Can progress to neuronal death (even if glycogen stores return to normal levels)
What conditions may the following clinical signs indicate in a cat?
Extreme lethargy, muscle twitches, unusual behaviour, loss of appetite, trembling, lack of coordination, blindness, unconsciousness
- Hypoglycaemia
- Hypoadrenocorticism
- Liver disease
- Neoplasia
- Sepsis
- Toxicosis
- Glycogen storage disease
- Polycythaemia
- Gastrointestinal disease
- Hypokalaemia
- Renal disease
- Neurological, or muscular
Compare the clinical signs of chronic vs. acute hypoglycaemia
Chronic adapt to low glucose so signs are inappropriately mild whereas in acute signs are usually severe
What factors should be taken into account when interpreting a hypoglycaemia in practice?
- Stress response in cats
- Septic hyperglycaemia can occur followed by a hypoglycaemic phase
- Incorrect tube choice
- Haemoconcetration falsely lowers blood glucose
What toxins lead to a hypoglycaemia?
- Xylitol
- Ethanol
- Beta-blockers
- Oleander extract
- Dried chicken pieces
What are the main mechanisms of hypoglycaemia?
- Excessive uptake of glucose by normal or neoplastic cells
- Impaired hepatic gluconeogenesis or glycogenolysis
- Malnutrition/starvation
- Deficiency in diabetogenic hormones
Give possible causes of excessive uptake of glucose by neoplastic cells
- Insulinoma
- Other non-beta cell neoplasms e.g. hepatomas and hepatic carcinomas
Explain how hypoglycaemia can occur due to neoplasms
Some can secrete insulin-like peptides and accelerate consumption of glucose by the tumour cells
Give examples of conditions that may lead to impaired hepatic gluconeogenesis or glycogenlysis
- Porto-systemic shunts
- Cirrhosis
Give an example of how deficiency in diabetogenic hormones can lead to hypoglycaemia
- Hypoadrenocorticism
- Causes increased uptake of glucose into cells and depletion from blood
- Impairs gluconeogensis and glucose production
Why might a diabetic animal present with low blood sugar?
- Overdose of insulin
- Sudden remission (cats)
- Anorexia
- Over exercising
- Systemic infectious diseases leading to lymphocytophilia
Why does xylitol intoxication lead to hypoglycaemia?
- Xylitol leads to excessive insulin prod. (2.5-7x greater than for equal amount of glucose)
- Liver failure also described
Following ingestion of xylitol, what advice should be given to an owner?
- Bring into practice ASAP
- Rub jam/honey onto gums to minimise degree of hypoglycaemia (does not need to swallow)
