Acute Care Flashcards
WHAT DOES SODIUM DO IN THE BODY?
Nerve conduction
Biocarbonate buffer system
What is the reference range of sodium?
135-145 mmol/L
What are some causes of hypernatraemia?
MODEL gets FRIED
2 C Conn’s + Cushing
Medications
Osmotic diuresis - for example, diabetic coma, diuretics
Diabetes insipidus
Excessive H2O loss
Low H2O intake
What are the symptoms of hypernatraemia?
MODEL gets FRIED
Flushed skin and fever
Restless, irritable, anxious
Increased blood pressure + fluid retention
Edema - peripheral and pitting
Decreased urine output and dry mouth
What is the treatment for hypernatraemia?
- IV 0.9% saline solution
- Slowly over 48 hours
- Too much fluid too fast can cause cerebreral oedema
What are some causes of hyponatraemia?
4 D’s + S cause SALT LOSS
Drugs (Diuretics e.g. furosemide, carbamazepine)
Diarrhoea
Dehydration
Drains
SIADH/Heart failure
What are the symptoms of hyponatraemia?
4 D’s cause SALT LOSS
Stupor/coma
Anorexia
Lethargy
Tendon Reflexes (decreased)
Limp muscles
Orthostatic hypotension
Seizures/headache
Stomach cramping
What is the treatment for hyponatraemia?
Treat underlying cause
- *Hypovolaemic hyponatraemia**
0. 5-1L 0.9% Saline
Normovolaemic (euvolaemic) hyponatraemia
Restriction of fluid intake to 500 ml per day to raise plasma sodium to 130 mM
Frequent measurements of plasma osmolality and sodium
Hypervolaemic hyponatraemia
Dietary sodium restriction and diuretic therapy are the mainstays of therapy
What can excessively rapid correction of hyponatraemia cause?
Central pontine myelinolysis
WHAT IS THE REFERENCE RANGE OF POTASSIUM?
3.5-5.0 mmol/L
What are some causes of hyperkalaemia?
Hyperkalaemia CARED for MURDER
- Cellular movement of K+ from intracellular to extracellular (burns, tissue damahge)
- Adrenal insufficiency - Addison’s disease/AKI/rhabdomyolysis
- Renal failure
- Excessive K+ intake
- Drugs (potassium-sparing drugs - spironolactone, Heparin)
What are the symptoms of hyperkalaemia?
hyperkalaemia CARED for MURDER
- Muscle weakness
- Urine output little or none
- Respiratory failure
- Decreased cardiac contractility
- Early: muscle twitches/cramps
-
Rythm changes
Tall peaked T waves, prolonged PR interval
What is the management of hyperkalaemia?
-
Cardiac protection
IV Calcium gluconate -
Shift potassium into cells
Insulin-glucose infusion - 10 units soluble insulin in 25g glucose
Nebulised salbutamol -
Remove potassium from body
Stop exaccerbating drugs e.g. ACE inhibitor
Calcium resonium (orally or enema)
Loop diuretics
Dialysis
All patients with severe hyperkalaemia (≥ 6.5 mmol/L) or with ECG changes should have emergency treatment
- IV calcium gluconate: to stabilise the myocardium
- Insulin/dextrose infusion: short-term shift in potassium from ECF to ICF
- other treatments such as nebulised salbutamol may be given to temporarily lower the serum potassium
What are the ECG changes in hyperkalaemia?
Hyperkalaemia causes a rapid reduction in resting membrane potential leading to increased cardiac depolarization, and muscle excitability which in turn causes ECG changes
- Tall tented T waves [T wave larger than R wave in > 1 lead]
- Widened QRS [>0.12 s]
* *P WAVES + PR interval** - Flattened or absent P waves
- First degree heart block (prolonged PR interval) [>0.2 s];
What are some causes of hypokalaemia?
DITCH the 7 L’s
- Drugs - loop diuretics e.g. furosemide / laxatives, glucocorticoids, hydrocortiosne
- Inadequate consumption of K+
- Too much water intake
- Cushing/Conn’s syndrome (causes kidneys to excrete K+)
- Heavy fluid loss (nasogastric tube suction, vomiting, diarrhoea, wound drainage)
What are the symptoms of hypokalaemia?
DITCH the 7 L’s
- Lethargic
- Low, shallow respirations
-
Lethal cardiac dysrhythmias
ST depression, shallow T wave, projecting U wave - Lots of urine
- Leg cramps
- Limp muscles
- Low blood pressure
What is a complication of hypokalaemia?
Hypokalaemia predisposes to arrhythmia, which could ultimately cause a myocardial infarction
What is the management of hypokalaemia?
Treat underlying cause
Replacement of potassium either IV or orally
What are the ECG changes in hypokalaemia?
After the QRS complex
- Flattened T waves
- ST segment depression
- Prolonged QT interval
- Tall U waves
Ventricular tachycardia or ventricular fibrillation and torsade de pointes
What is the maximum rate potassium can be given?
10 mmol/hour
WHAT IS THE REFERENCE RANGE OF CALCIUM?
2-2.60 mmol/l
What are the causes of hypercalcaemia?
CHIMP gets STONES, MOANS, GRAONS
Calcium supplements
Hyperparathyroidism
Iatrogenic
Multiple myeloma
Parathyroid hyperplasia
What are the symptoms of hypercalcaemia?
CHIMP gets Stones, bones, abdominal moans, and psychic groans
GI problems ‘moans’
Constiaption
Nausea and vomiting
Renal ‘stones’
Polyuria
Nephrolithiasis
Skeleton ‘bones’
Bone pain
Arthritis
Neuromuscular ‘psychic groans’
Lethargy and fatigue
Weakness
What is the treatment of hypercalcaemia?
- Normal saline - typically 3-4 litres/day.
- Following rehydration bisphosphonates may be used. They typically take 2-3 days to work with maximal effect being seen at 7 days
-
Other options include:
* *Calcitonin** - quicker effect than bisphosphonates
* *Steroids** in sarcoidosis
Loop diuretics such as furosemide are sometimes used in hypercalcaemia, particularly in patients who cannot tolerate aggressive fluid rehydration. However, they should be used with caution as they may worsen electrolyte derangement and volume depletion.
What are the ECG changes for hypercalcaemia?
Shortening of the QT interval
What are the causes for hypocalcaemia?
- Vitamin D deficiency (osteomalacia)
- Chronic kidney disease
- Hypoparathyroidism (e.g. post thyroid/parathyroid surgery)
What are the symptoms of hypocalcaemia?
Convulsions
Arrhythmias
Tetany
Spasms and stridor (Chvostek - FACE, Trosseau - HAND)
Numbness in the fingers
What is the diagnosis of some conditions that cause hypocalcaemia?
Uraemia and an elevated serum creatinine indicate chronic renal failure
Elevated serum phosphate and normal renal function indicate hypoparathyroidism - skeletal abnormalities will indicate pseudohypoparathyroidism
Hypoparathyroidism due to hypomagnesaemia produces a hypocalcaemia uncorrected by calcium
What is the treatment of hypocalcaemia?
- IV calcium gluconate, 10ml of 10% solution over 10 minutes
- ECG monitoring is recommended
What are the ECG changes in hypocalcaemia?
Lengthening of the QT interval
What is the transfusion threshold for patients?
How long should the blood be given?
Patients without ACS Patients with ACS
Transfusion threshold 70 g/L 80 g/L
Target after transfusion 70-90 g/L 80-100 g/L
90-120 mins
What must be prescribed between two units of packed red blood cells?
Furosemiude to prevent fluid overload
What is the rate of infusion of an insulin drip in DKA?
0.1 unit/kg/hour
What is the maintenance fluids for a child?
- 1st 10kg of body weight = 100 ml/kg/day
- 2nd 10kg of bodyweight = 50 ml/kg/day
- Remainder of bodyweight = 20 ml/kg/day
What is the maintenance fluids for an adult?
What is the maintenance ions for an adult?
What is the maintenance of glucose for an adult?
- 25 ml/kg/day
- 1 mmol/kg/day - potassium, sodium + chloride
- 50-100g/day of glucose
WHAT IS HAPPENING IN DKA?
DKA is caused by uncontrolled lipolysis (not proteolysis) which results in an excess of free fatty acids that are ultimately converted to ketone bodies
What are the features of DKA?
- Abdominal pain
- Polyuria, polydipsia, dehydration
- Kussmaul respiration (deep hyperventilation)
- Acetone-smelling breath (‘pear drops’ smell)
What are the diagnostic criteria for DKA?