Case 11 - DKA Flashcards
HHS is more common in Type _ Diabetes
DKA is more common in Type _ Diabetes
HHS is more common in Type 2 Diabetes
DKA is more common in Type 1 Diabetes
Name 5 triggers of DKA (the 6 i’s)
Infection Infarction Insulin withdrawal Intoxication Intercurrent illness Iatrogenic (e.g. corticosteroids)
Describe the pathophysiology of polyuria, polydipsia, and glycosuria in DKA
Absolute insulin deficit –> Glucose cannot enter cells –> cells starved of glucose, body starts releasing catabolic hormones to try and increase BGL concentration –> inc. gluconeogenesis + glycogenolysis, decreased glycolysis –> polyuria, polydipsia, glycosuria
What leads to ketoacidosis? Describe the pathophysiology.
Glucose not entering cells –> lipolysis to use fat as an energy source –> free fatty acids (FFAs) released from adipose tissue –> FFAs undergo ketogenesis in the liver –> ketones released –> fuck shit up
What is the typical biochemistry finding in DKA?
Metabolic acidosis with elevated anion gap
What is the PATHOPHYSIOLOGY behind the typical biochemistry finding in DKA?
Ketones released after FFA metabolism in the liver –> presence of 2 acidic ketones (acetoacetic acid & beta-hydroxybutyric acid) –> serum bicarbonate consumed to act as a buffer –> HIGH ANION GAP METABOLIC ACIDOSIS (HAGMA)
How does DKA cause hyperkalemia?
Ketone bodies give off protons (H+) –> acidosis –> H+ pumped INTO cells whilst K+ is pumped OUT –> K+ accumulates in ECF –> insulin drives Na+ / K+ ATPase pumps, so the lack of insulin means there’s no driving force to bring K+ BACK INTO the cell –> decreased total body K+ and normal or paradoxically INCREASED SERUM K+
https://www.youtube.com/watch?v=jCf7W1U4JKE
List 3 consequences of hyperkalemia
- Arrhythmias (–> palpitations, chest pain)
- Ileus (–> abdominal pain)
- Muscles weakness
Describe the characteristic DKA presentation (separate into those shared by DKA & HHS vs. those that are specific to DKA)
DKA SPECIFIC: RAPID (<1 day onset), fruity breath (acetone breath), abdo pain, Kussmaul breathing
DKA & HHS: polyuria, polydipsia, recent weight loss, NV, dehydration, altered mental status (drowsiness, confusion, coma)
List 5 important investigations used to assess a hyperglycaemic cr.isis (DKA & HHS)
- BGL
- Ketones (urine & serum)
- ABG
- BMP
- Serum osmolality
List 5 important investigations used to assess a hyperglycaemic crisis (DKA & HHS)
- BGL
- Ketones (urine & serum)
- ABG
- BMP
- Serum osmolality
Differences in the following investigation findings in DKA vs. HHS:
- BGL
- Ketones (urine & serum)
- ABG
- BMP
- Serum osmolality
- BGL: in DKA is typically <33.3mmol/L. In HHS typically >33.3mmol/L
- Ketones (urine & serum): in DKA moderate-severe ketonuria. In HHS little to no ketonuria.
- ABG: in DKA pH<7.30. In HHS ph>7.30
- BMP: in DKA will be metabolic acidosis with high anion gap. HHS has normal anion gap
- Serum osmolality: normal in DKA. High in HHS.
DKA is the diagnosis in patients with type 1 diabetes who have __________, _________, and ___ anion gap metabolic ________ with decreased ________!
HHS is the diagnosis in type 2 diabetes patients with ___________ and ______________.
DKA is the diagnosis in patients with type 1 diabetes who have hyperglycemia, ketonuria, and high anion gap metabolic acidosis with decreased bicarbonate!
HHS is the diagnosis in type 2 diabetes patients with HYPERGLYCAEMIA and HYPEROSMOLALITY
Why is DKA treatment (fluids, K+, insulin) administered gradually? Which complication does this prevent?
Cerebral oedema (more common in paediatrics)
The most important findings in DKA are…
DDKAA
DDKAA
Delirium/psychosis Dehydration Kussmaul respirations Abdominal pain / nausea / vomiting Acetone (fruity) breath
What is the treatment protocol for DKA?
- Low-dose short-acting IV insulin
- IV saline
- Electrolyte (particularly K+) repletion once insulin is started
- IV bicarbonate (in severe cases of deficiency: <10mmol/L)
- Identify and treat underlying cause
When should K+ repletion be initiated BEFORE insulin?
When potassium < 3.3mEq/L, give potassium chloride (KCl) before starting insulin
Potassium replacement is initiated immediately if the serum potassium is ____ mEq/L as long as there is adequate urine output
Potassium replacement is initiated immediately if the serum potassium is <5.3 mEq/L as long as there is adequate urine output
Low-dose intravenous (IV) insulin should be administered to all patients with moderate-severe DKA who have a serum potassium ≥ ___ mEq/L.
If the serum potassium is less than ___ mEq/L, insulin therapy should be delayed until K+ replacement has begun and the serum concentration has increased.
Low-dose intravenous (IV) insulin should be administered to all patients with moderate-severe DKA who have a serum potassium ≥ 3.3 mEq/L.
If the serum potassium is less than 3.3 mEq/L, insulin therapy should be delayed until K+ replacement has begun and the serum concentration has increased
Why is insulin administration delayed in patients with a serum K+ of <3.3mEq/L
Insulin will only deplete serum K+ further by driving it into the cells
Why is insulin administration delayed in patients with a serum K+ of <3.3mEq/L
Insulin will only deplete serum K+ further by driving it into the cells (Na+/K+ ATPase pumps on cells require insulin to work)
What is the pathophysiology behind kussmaul breathing?
Increased protons (H+) in the blood –> stimulates peripheral chemoreceptors –> info travels via vagus & glossopharyngeal nerve to CNS –> stimulates increased respiratory rate in an attempt to breathe off more CO2 and bring the pH back up
What is the pathophysiology behind fruity/acetone breath?
Increased protons (H+) in the blood –> stimulates peripheral chemoreceptors –> info travels via vagus & glossopharyngeal nerve to CNS –> stimulates increased respiratory rate in an attempt to breathe off more CO2 and bring the pH back up –> breathing off KETONES in addition to CO2
What is responsible for the reflex tachycardia and sweating seen in DKA?
Dehydration –> decreased blood volume –> activation of baroreceptors –> increased SNS activity –> tachycardia, diaphoresis