10. Critical Care Flashcards
(120 cards)
Why is it important to consider pain in the post op patient that you suspect is shocky?
Because pain can cause tachycardia and dyspnoea
Why should BP not be relied upon to predict if a P is seriously unwell?
Because it can be compensated and appear normal until later stages of decompensated shock
What type of problem affects the kidneys? Respiratory or circulatory?
Circulatory
If the pH is abnormal - what should you look at?
pCO2
When does a pCO2 indicate
(a) respiratory acidosis
(b) respiratory alkalosis?
What is the normal range for pCO2?
(a). >6.0 kPa
(b) <4.7 kPa
Normal range = 4.7 - 6.0
How can you check if the acidosis or alkalosis is respiratory or metabolic?
Check the bicarbonate levels
What is the normal range for serum bicarb?
What levels indicate
(a) metabolic acidosis
(b) metabolic alkalosis
Normal range -
How is metabolic acidosis / alkalosis compensated?
Rapidly compensated by inc / dec breathing - to inc/dec CO2 levels
How is respiratory acidosis / alkalosis compensated?
Slowly - via renal changes effecting loss or retention of bicarb
What can cause respiratory alkalosis?
Anything that increases RR or tidal vol
- pain
- PE
- sepsis
- pneumonia
What can cause respiratory acidosis?
Anything that decreases RR or tidal volume
- Respiratory failure = severe pneumonia, sedation, opioids, COPD
How does increased CO2 levels affect a P?
Causes obtundation and sedation
What can cause metabolic acidosis?
Hypoperfusion
Failure of kidney to secrete acid
Inc bicarb loss from the kidney or gut
What can cause metabolic alkalosis?
Loss of acid (e.g. vomiting)
What is abdominal splinting?
Pain in the abdomen which restricts breathing as a result
What is atelectasis?
Partial collapse of a lung
Why do we use humidified O2 when oxygenating Ps?
To prevent the drying out of the respiratory epithelium
What levels of O2 are acceptable in a P? (Sats and PaO2)
Sats of 94% +
PaO2 of 8-9 kPa
At what level of PaCO2 may induced unconsciousness occur?
8 kPa +
What is the normal levels of O2 sat and PaO2 in a person?
98% saturation - about 12kPa PaO2
What is the minimum amount of O2 sats and PaO2 before the dissociation curve of O2 to Hb drops very steeply?
Around 90% saturation at 8 kPa
If O2 in the room is 21% and atmospheric pressure is 100kPa, why isn’t normal PaO2 20 kPa?
Because O2 in the alveolus is diluted with CO2 and water vapour
How much less should the PaO2 be than the inspired O2 concentration?
About 10 less (5 kPa CO2 and 4.5 kPa H20)
If a P is on inspired O2 at 30% - what should their arterial PaO2 be?
20 kPa