Lecture 30: Chemical Pathology of GERR Flashcards
give some examples of sample types that would be sent to the lab
- blood
- urine
- CSF
- faeces
- sputum
- saliva
- lavage
- pus
- fluid from a drain
- pleural fluid
- ascites fluid
- synovial fluid
- semen
- mucous membrane swabs
- tissue
what is the difference between serum and plasma
plasma contains clotting factors, serum does not (as clotting has occurred)
when might you expect abnormal chloride levels
- chloride generally follows Na (if Na ^ so is chloride)
- if not it could be an error in sample collection
- chloride very low in vomiting
how might a total CO2 result present as abnormal
- acid-base abnormality might be present
- if low level, indicates metabolic acidosis e.g. DKA
what is urea and when might you see high urea levels
end point of protein metabolism
- GI bleeding
- dehydration
- Kidney failure
what is creatinine and when might high levels
waste product of muscle metabolism
- more muscle, more creatinine
- compare to previous values –> a large rise may indicate AKI
what is used to estimate GFR
- complicated equation
- -> CKD-EPI or MDRD
- use age, gender, (ethnicity) and creatinine
how can hyponatraemia cause death
- less Na+ in blood so blood more dilute
- water moves from blood into brain cells by osmosis
- causes brain swelling (cerebral oedema)
- brain moves through only opening (foramen magnum)
- cause compression of vital brain structures
what is the risk w/ hypernatraemia and what Px are mostly affected
- severe dehydration
- usually in elderly or debilitated patients
- rarely in diabetes insipidus
causes of hypokalaemia
too little in:
- chronic malnutrition
shift from blood to cells:
- alkalosis
- re-feeding syndrome
- drugs e.g. salbutamol, insulin
too much out:
- hyperaldosteronism
- diuretics
- diarrhoea and vomiting
causes of hyperkalaemia
too much in:
- over-zealous IV replacement
shift from blood to cells
- acidosis
- tissue damage e.g. rhabdomyolysis
too little out:
- kidney failure (acute or chronic)
- hypoaldosteronism
- drugs e.g. ACEi, ARBs, K+ sparing diuretics
what must you monitor after treating hyperkalaemia and why
blood glucose - big drop in blood glucose can occur
what is commonly seen on liver profile to suggest hepatitic picture on liver
predominantly high ALT and AST
what is commonly seen on liver profile to suggest cholestatic picture on liver
predominantly high ALP and GGT
what synthetic liver function test could suggest liver failure
- ^ prothrombin time
- low albumin
