Lecture 13- ECG and [K+]

Question 1

hypokalaemia

Answer 1

• Potassium level <3.5 mmol/L o Moderate hypokalaemia is a serum level of <3.0 mmol/L o Severe is <2.5 mmol/L

Question 2

decreased extracellular potassium causes

Answer 2

myocardial hyper-excitability

Question 3

signs and symptoms of hypokalaemia

Answer 3

• Generalised muscle weakness - Respiratory depression - Ascending paralysis - Ileus, constipation - Palpitations, arrhythmia, cardiac arrest

Question 4

hypokalaemia ECG

Answer 4

• Peaked P wave
• T waves flattening and inversion
• U wave

Question 5

hyperkalaemia

Answer 5

>5mmmol/l

Question 6

in hyperkalaemia the heart becomes

Answer 6

less excitable - Resting membrane potential becomes less negative - Causes some voltage gated na+ channels to be inactivate (conduction problem)

Question 7

hyperkalaemia can lead to

Answer 7

o Generalised muscle weakness o Respiratory depression o Ascending paralysis o Palpitations, arrhythmia, cardiac arrest

Question 8

hyperkalaemia ECG

Answer 8