Answers:
PH = 7.56, that is moderate alkalaemia
HCO3 = 38.4 mmol/L, so we have metabolic alkalosis.
Next, we will calculate the compensation. For metabolic alkalosis we use the following equation:
Category Archives: Lab Cases
Lab case 406
An alcoholic man presented to the emergency department after suffering from a seizure. His venous blood gases showed the following:
PH = 7.56
pCO2 = 42 mmHg
Lab case 405 interepretation
Answers:
PH = 7.30, that is mild acidaemia.
pCO2 = 65 mmHg. So, we have respiratory acidosis.
Next, we need to look at the compensation. Compensation for respiratory acidosis is different between acute and chronic cases.
Lab case 405
60 year-year-old man with history of DM and x-smoker but not known to have COPD. Presented to an emergency department with shortness of breath. His blood gases showed the following:
PH = 7.30
pCO2 = 65 mmHg
Lab case 404 interpretation
PH = 7.395, that is within normal range.
pCO2 = 42 mmHg, Normal for venous blood gases ( Normal pCO2 is 40 mmHg for arterial blood and 48 mmHg for venous).
HCO3 = 25 mmol/L. that is very slightly above the normal (normal level is 24)
Lab case 404
25 year-old-man with type 1 DM presented with diarrhoea and vomiting. His VBG showed the following:
PH = 7.395
pCO2 = 42 mmHg
pO2 = 54 mmHg
Lab case 403 interpretation
PH = 7.745, that is severe alkalaemia.
pCO2 = 36 mmHg is low so we have respiratory alkalosis. However this value is very close to normal value of 40. This won’t explain the severely elevated PH.
Lab case 403
48-year-old man with history of Crohn’s disease and previous cardiac arrest. This patient presented with diarrhoea and vomiting for 2 days. His first VBG showed the following:
PH = 7.745
Lab case 402 interpretation
Answers:
Ph = 7.56, that is alkalaemia
Both HCO3 and pCO2 are low. So, most likely we have combined metabolic and respiratory alkalosis. We will start with the metabolic alkalosis as it is easier to run the calculations for the blood gases on the metabolic side.
Lab case 402
70-year-old diabetic man presented with vomiting. His venous blood gases showed the following:
PH = 7.56
pCO2 = 19 mmHg