Critical Care and the unwell patient post surgery Flashcards
What is the definition of shock?
1 - lack of respiratory drive
2 - failure of circulation to provide adequate perfusion of tissues
3 - increases tachycardia
4 - syncope
2 - failure of circulation to provide adequate
- various classes ranging from I - IV
Acid-base disorders is a pathologic change in CO2 partial pressure (Pco2) or serum bicarbonate (HCO3−) that typically produce abnormal arterial pH values. What is the normal pH of blood?
1 - 7.30 - 7.45
2 - 7.20 - 7.45
3 - 7.35 - 7.45
4 - 7.34 - 7.65
3 - 7.35 - 7.45
<7.35 = acidosis
<7.45 = alkalosis
Acid-base disorders is a pathologic change in CO2 partial pressure (Pco2) or serum bicarbonate (HCO3−) that typically produce abnormal arterial pH values. If the PCO2 is >6.0 kPa (45mmHg) is this respiratory acidosis or alkalosis?
- respiratory acidosis
Acid-base disorders is a pathologic change in CO2 partial pressure (Pco2) or serum bicarbonate (HCO3−) that typically produce abnormal arterial pH values. If the PO2 is <4.7 kPa (35mmHg) is this respiratory acidosis or alkalosis?
- respiratory alkalosis
Bases are HCO3-
Acids are CO2
What is the normal range for a base excess?
1 - +1 to +2
2 - -1 to +2
3 - -2 to +2
4 - 0 to +2
3 - -2 to +2
- normal we would expect, but the range can be - or +2
Acid-base disorders is a pathologic change in CO2 partial pressure (Pco2) or serum bicarbonate (HCO3−) that typically produce abnormal arterial pH values. If the HCO3- is <24mmol/l or a base excess (BE) < -2 is this metabolic acidosis or alkalosis?
- metabolic acidosis
Acid-base disorders is a pathologic change in CO2 partial pressure (Pco2) or serum bicarbonate (HCO3−) that typically produce abnormal arterial pH values. If the HCO3- is >24mmol/l or a base excess (BE) > +2 is this metabolic acidosis or alkalosis?
- metabolic alkalosis
Is a metabolic alkalosis or acidosis compensated for quickly by respiration or renal function?
- respiratory is rapid response
- changes in CO2 retention or expiration
Is a metabolic alkalosis or acidosis compensated for slowly by respiration or renal function?
- renal function is slow
- retains or excretes HCO3-
Which of the following does NOT typically cause respiratory alkalosis?
1 - PE
2 - pneumonia
3 - sepsis
4 - pain
5 - vomiting
5 - vomiting
- all others cause respiratory alkalosis due to hyperventilation
Which of the following does NOT typically cause respiratory acidosis?
1 - severe pneumonia
2 - sedation/opioids
3 - ontubdation (drowsy)
4 - diarrhoea
4 - diarrhoea
- all others reduce respiration and therefore retain CO2
Which of the following does NOT typically cause metabolic acidosis?
1 - hypoperfusion
2 - kidney failure
3 - vomiting
4 - gut dysfunction
3 - vomiting
Which of the following cause metabolic alkalosis?
1 - hypoperfusion
2 - kidney failure
3 - vomiting
4 - gut dysfunction
3 - vomiting
- loss of HCL so too much HCO3-
The oxygen-hemoglobin dissociation curve shows the relationship between haemoglobin saturation with O2 (SO2) and partial pressure of O2 (PO2).
Partial pressure is a measurement of the individual components of a mixture of gas. Therefore if PO2 is high then there is more change for more O2 to bind with haemoglobin.
Haemoglobin absorbs different wavelengths of light depending on the degree of saturation. This is the basis of how pulse oximetry works.
Which of the following is the main driver of haemoglobin saturation?
1 - iron
2 - haematocrit
3 - PO2
4 - copper
3 - PO2
- more O2 means more O2 to bind to haemoglobin
The oxygen-hemoglobin dissociation curve is plotted as a sigmoidal shape. What relevance does this have?
1 - less O2 affinity as O2 binds to haemoglobin
2 - increased O2 affinity as O2 binds to haemoglobin
3 - no relationship
2 - increased O2 affinity as O2 binds to haemoglobin
- essentially easier to bind the 4th O2 molecule than the first O2 molecules
What is typically deemed an acceptable % saturation of O2 to haemoglobin that is sufficient to ensure adequate tissue perfusion?
1 - 90%
2 - 94%
3 - 75%
4 - 60%
2 - 94%
- roughly = to 60mmHg
If a patient switches to anaerobic metabolism this can lead to an increase in what being released and diffusing into the blood?
1 - CO2
2 - O2
3 - Cl-
4 - K+
1 - CO2
- causes increased PCO2
- more CO2 binds to RBCs
- carbonic anydrase converts H20 and CO2 into HCO3- and H+