Endocrine

Question 1

Define diabetes

Answer 1

a group of metabolic diseases characterised by hyperglycaemia due to problems with insulin secretion and/or the action of insulin on the cell
An increase in glucose levels results in an increase in insulin production, and vice versa when glucose levels decrease

Question 2

What are the different types of diabetes?

Answer 2

Type 1: genetic, inability to produce insulin
Type 2: developed insulin resistance, requires supplementary insulin
Induced: onset, acute due to management eg. drugs
Gestational: acute, during pregnancy

Question 3

Define hyperglycaemia

Answer 3

Lack of insulin means glucose accumulates in the blood, resulting in fluid shifting from the cells to the intracellular space. renal threshold is exceeded resulting in glucose being passed in the urine

Question 4

Define fluid shift

Answer 4

Fluid shift causes cells to become dehydrated which stimulates the thirst response (polydipsia), Results in increased blood volume causing a diuresis (polyuria)
Fluid shifting and diuresis results in large losses of electrolytes (K+ and Na+)

Question 5

Define alternative sources of glucose

Answer 5

As glucose cannot enter cells, cells are ‘starved’ simulating a feeling of hunger (polyphagia)
Body looks for alternate source of glucose which exacerbates hyperglycaemia: breakdown of glycogen to glucose in liver, and
breakdown of fats to glucose

Question 6

Define how acidosis develops

Answer 6

Ketones are a by-product of breaking down fats to glucose
Ketones accumulate in the blood resulting in acidosis
Acidosis contributes to electrolyte imbalance by decreasing K+

Question 7

What is the pathophysiology of diabetes?

Answer 7

glucose accumulates in blood -> hyperglycaemia -> fluid shifts out of cells -> increased fluid volume stimulates polyuria -> large losses of electrolytes -> cells seek alternate sources of glucose by breaking down glycogen and fats -> ketones are a by-product of breaking downs fats to glucose -? ketones accumulate in the blood -> blood becomes acidic -> electrolytes further decreased

Question 8

Outline Diabetic Ketoacidosis (DKA)

Answer 8

a life threatening complication of diabetes. Usually associated with Type 1 diabetics. Onset of DKA is rapid and can be severe within hours
DKA results in acidosis, dehydration, and electrolyte imbalances. it is diagnosed when three states are present:
Hyperglycaemia, ketosis, acidosis

Question 9

What are the most common causes of DKA?

Answer 9

imbalance in insulin and glucose
stress (physical and psychological)
infection
AMI

Question 10

What investigations are done to determine DKA?

Answer 10

BGL, blood ketones, venous blood gas, pathology

Question 11

What are the clinical manifestations of DKA

Answer 11

polyuria, polyphagia, polydipsia
abdominal pain
nausea and vomiting
acetone breath (sweet, fruity smell)
deep, rapid respirations (Kussmaul respirations)
tachycardia
hypotension
dry mucous membranes
altered conscious state (confusion and drowsiness)
coma

Question 12

Outline Hyperglycaemic Hyperosmolar Syndrome (HHS)

Answer 12

Occurs when blood glucose levels remain high for an extended period of time. Onset is in days to weeks compared to DKA. critical differences include less severe insulin deficiency, less severe fluid loss, and none/limited ketone production

Question 13

What are common causes of HHS?

Answer 13

infection, stroke, AMI and some medications such as diuretics and steroids

Question 14

What are the investigatory methods for HHS?

Answer 14

BGL, blood ketones, pathology

Question 15

What are the clinical manifestations of HHS?

Answer 15

the same as DKA except:
they are more dehydrated
have developed renal failure
may not require insulin therapy (type 2 diabetics are producing some insulin)
normal to slightly elevate ketones (some insulin means that fats are not broken down for fuel)
severe electrolyte imbalances

Question 16

What is insulin’s relation to diabetes?

Answer 16

due to a relative or absolute lack of insulin
insulin required for glucose to enter cells -> without insulin glucose cant enter cells -> glucose accumulates in the blood = hyperglycaemia

Question 17

What is the effect of hyperglycaemia on metabolism?

Answer 17

the blood becomes hyperosmolar -> water in the cells is drawn into the ECF -> thirst is triggered as cells becomes dehydrated -> intravascular volume increases -> diuresis -> polyuria -> cells ‘hungry’, increasing general appetite -> further hyperglycaemia -> continuing diuresis and polyuria -> excess glucose reabsorbed in kidneys -> glucose excreted in urine -> sodium and potassium diluted by fluid shifting -> hypokalaemia -> potassium drawn out of cells into intravascular -> excess potassium excreted in urine

Question 18

What is the link between diabetes and ketones?

Answer 18

Cells that are starved fro glucose will breakdown fats and protein into glucose -> by-product of fat breakdown is ketones -> ketones acculumate in the blood -> blood becomes acidic (ketoacidosis)

Question 19

what are the key aspects of DKA/HHS?

Answer 19

Hyperglycaemic
Acidotic
Hypokalaemic and electrolyte imbalances
Dehydrated

Question 20

What are the principles behind DKA and HHS management?

Answer 20

Rehydration and correction of electrolyte imbalances
Correction of hyperglycaemia and acidosis
Identify and correct the underlying cause

Question 21

List the prioritisation of management of DKA and HHS

Answer 21

1. IV Normal Saline (correct dehydration)
2. IV short acting insulin (usually Actrapid) on a sliding scale (correct hyperglycaemia)
3. IV potassium (correct hypokalaemia)
4. IV glucose (correct hypoglycaemia)

Question 22

List some management considerations for DKA/HHS

Answer 22

1/24 BGL and blood ketone monitoring
1/24 electrolyte checks (consider venous blood gases)
Oxygen therapy (if required)
Keep patients NBM for at least 24 hours
1/24 urine measurements with strict FBC
Cardiac monitoring (especially if altered potassium)
MSU, ECG and other pathology (e.g. FBC) to identify any source of infection
Vital sign monitoring

Question 23

What is the difference between DKA and HHS?

Answer 23

DKA is associated with hyperglycemia and ketoacidosis, whereas HHS mainly has severe hyperglycemia and hyperosmolarity (no ketoacidodis)
DKA usually affects type 1 diabetes, HHS usually affects type 2 diabetes