electrolyte and acid base talk Flashcards
(25 cards)
what is the normal level of urea?
»Serum Urea 1.7- 8.3 mmol/l
when is urea decreased?
liver disease
when is uread increased?
- intravascular depletion
- blood meal
- renal failure
what symptoms will you get if urea >20
Nausea,
decreased appetite,
itchiness,
tiredness,
smelly breath,
metallic taste in mouth,
what symptoms do you get if urea>60
extreme ureamic frost,
uraemic pericarditis,
encephalopathy
how are ckds characterised in terms of EGFR?
»CKD 1 eGFR >90mls
»CKD 2 eGFR >60mls
»CKD 3a eGFR >45mls
»CKD3b eGFR > 30mls
»CKD 4 eGFR > 15mls
»CKD 5 eGFR < 15mls
What is the average EGFR fpr starting dialysis in the uk?
8
what can cause hyponatraemia?
Intra-renal factors
Defect with Na/Cl transport out of TAL/DCT
Continued secretion of ADH, stimulated by non-osmotic mechanism
what is the serum k level normally?
»Serum K = 3.2-5.1 mmol/L
which things cause hypokalaemia by redistributing potassium back into the cells?
˃insulin, theophylline, adrenergic use- like salbutamol
what things can cause potassium loss >20mmol/l?
- Drugs, diuretics, aminoglycosides, amphotericin- antibiotics and antifungals
- RTA or metabolic acidosis
- Low BP Bartter’s or Gittlemans- structural glomerular issues
- High BP
- High Aldosterone normal Cortisol – hyperaldoseronism
- Low Aldersterone normal cortisol - Liddle’s
- Low Aldersterone high Cortisol – Cushings Syndrome
what are chronic cardiac complications of hypokalaemia?
˃Cardiovascular
+Hypertension
+Ventricular tachyarrhythmias
what are endcrine complications of chronc hypokalaemia?
˃Endocrine
+Impairs insulin activity & sensitivity
what effect does chronic hypokalaemia have on muscles?
+Impairs muscle contraction (weakness)
what effects does long term hypokalaemia have on the kidneys?
+Mild tubulointerstitial fibrosis
+Renal cyst formation
+Metabolic alkalosis (increased net renal acid excretion)
+Polyuria
what is the effect og chronic hypokalaemia on the liver?
+Increases renal ammonia production which may worsen hepatic encephalopathy
what is the cause of hyperkalaemia?
1) Impaired renal excretion- CKD4/5
+Drugs impairing secretion – Spironolactone, amiloride, ACE-I, ARB
+Increased K load – rhabdomyolysis, haemolysis, GI bleed
2) Increased intake
3) Pseudohyperkalaemia
+haemolysis
–during blood collection/storage
–Rheumatoid/infectious mononucleosis
Any increase in plasma (or serum) potassium resulting from in vivo hemolysis is true hyperkalemia. By contrast, in vitro hemolysis is a process that only occurs in blood removed from the body and is due to mechanical disruption of erythrocytes induced by the process of blood collection and handling.
what are the 3 strategies for treating hyperkalaemia?
- Back into cells
˃Salbutamol, insulin and dextrose, sodium bicarbonate( if acidotic)
- Stabilisation
˃Calcium gluconate- stabilises the cardiac membrane
- Removal
˃If passing urine, Pee it out, iv fluids and diuretics
˃dialysis
what is the treatment of metabolic acidosis when it is severe <7.2
»isotonic NaHCO3 1.26%
what is a risk of giving exogenous sodium during metabolic acidosis?
»Exogenous Na load can exacerbate fluid overload & Htn
how does the kidney respond to metabolic alkalosis?
˃K+ depletion
˃Cl- depletion
where is calcium reabsorbed?
loop of Henle and distal tubule
what is the normal serum calcium
2.2-2.6mmol/l
what is normal serum phsphate?
»0.85 to 1.6mmol/l
