Question 1 answer
PH = 7.222 that is acidaemia. (Moderate)
PCO2 = 87.8. So, we have respiratory acidosis
Next we will calculate the compensation. For acute respiratory acidosis, compensation should be (24 + 1x(“PCO2-40”/10))
24 + (88-40)/10 = 28.4
For Chronic respiratory acidosis, compensation should be (24 + 4x”PCO2-40”/10)
24 +4(88-40)/10 = 41.5
PCO2 for this lady was 34.7 mmHg, so we have acute on chronic respiratory acidosis.
AG= 138-(99+34.7) = 4.3 Accordingly, there is No associated metabolic acidosis.
Unfortunately we can’t calculate A-a gradient as it was a venous gas
Conclusion: acute on chronic respiratory acidosis.
Question 2 answer
Although hypoxia can cause cardiac arrest, it usually causes progressive bradycardia then PEA then asystole.
VF is usually ischemic, this can be caused by arterial occlusion. Severe hypoxia can lead to myocardial ischemia as part of generalized hypoxia.
We still need to consider the 4Hs and 4Ts…. However, post VF arrest is ischemic usually and we should activate the cathlab or contact the cardiology consultant urgently (STEMI equivalent).
Treatment should focus on 2 aspects
- Apply post resuscitation care
Check ABCD, Get ECG, Find the cause, Targeted tempreture control and check and control ventilation.
VF arrest-Ischemia: that is Aspirin, Ticagrilor and heparin then Cathlab referral or thrombolysis.
- Ventilation, for treatment of acute on chronic respiratory acidosis (Type 2 respiratory failure), that can be achieved through BiPAP either through a mask or an ETT, depending on conscious level.