An Abnormal Blood Test Flashcards
What is hyperkalaemia?
Abnormally high potassium conc. in the blood
Normal range = 3.5mmol/l - 5.3mmmol/l
Where is most of the body’s potassium stored?
Why is this important?
98% stored within cells
2% in blood
Difference between high potassium concentration inside cells and low potassium concentration outside cell forms an electrochemical gradient forming a resting membrane potential
What is the risk of too much potassium in the blood?
Conc. of K+ in blood becomes closer to the intracellular conc., which decreases the electrochemical gradient across the cell membrane
Leads to an increased tendency for cellular depolarisation and makes it more difficult for cells to repolarise in time for a new action potential
How might hyperkalaemia present clinically?
Skeletal muscle = pain, cramps, weakness, or paralysis
Cardiac muscle = fatal arrhythmias, cardiac arrest
What causes hyperkalaemia?
- Excessive potassium intake
- Failure to remove enough potassium - damaged kidney function
- Redistribution - body potassium has shifted from inside the cells into the extracellular fluid e.g. due to medications, insulin dificiency, hypoaldosteronism, metabolic acidosis etc. May suggest cell lysis
- Falsely elevated potassium - conditions that cause cell lysis e.g. prolonged use of tourniquet, severe burns, tumour lysis
How is hyperkalaemia treated?
- Stabilise cardiac membrane - give IV calcium glutonate, reduced excitability of cardiac myocytes
- “Shift” potassium into cells using medications
- Reduce potassium intake - give potassium binding resins to prevent it from being absorbed in the gut
- Correct underlying mechanism - treat cause e.g. dialysis for renal failure, insulin for DM
Case Study for abnormal blood result:
79F - been in hospital for 3 weeks, community acquired pneumonia
Observations: BP - 130/90 HR - 98 O2 sats - 98% on air RR - 16 Alert
K+ came back as 6.7 mmol/l
No chest pain, no palpitations or weakness
What do you think of the communication between sister Nicole and the biochemistry laboratory?
No intro from biochem dude
Does confirm patient using hospital number, not name though
Does confirm he was speaking to the Nurse, Nicole
Polite, thanks Nicole
What do you think of the communication between sister Nicole and Oliver, the F1 doctor, over the telephone?
Polite, friendly, introduced himself and his role
Nicole introduces herself
Oliver clear in requests, but gives many instructions at once
She asks how long he will be
Civil - ask each other to do things rather than telling
What do you think of the communication with the patient?
Lot of information spoken in front of patient with little explanation
Medical jargon
F1 doc does update patient superficially
Can you identify aspects of this scenario which would be high risk for a safety error?
Need to ensure correct patient to provide urgent treatment and avoid harm to others
Confirming correct patient over the phone (both lab and F1), check patient identification bands when taking blood. Confirm name, DOB, hospital number and location
Can you identify aspects of this scenario which would be high risk for a safety error?
Lab didn’t confirm who they were - hard to account for where the info came from
Nurse doesn’t give F1 a hospital number, just patient’s name
F1 asks nurse to do many followups without checking if she understood it all
Not clear who will follow up the repeat results
Not clear who will look over the repeat ECG in 30 mins
What should the nurse do if things deteriorate?
Hasn’t looked for a cause - dehydration? Fluid assessment needs to be completed
How could the risk of something being missed be minimised in this scenario?
F1 could have made sure that nurse understood what he was asking
F1 could have safety netted what to do if patient deteriorated
