Describe and interpret this arterial blood gas: History: A 50-year-old man with systemic sclerosis and altered bowel habit presents with dyspnoea and hypotension. pH 7.18 Na 141 mmol/L pCO2 48 mmHg K 1.5 mmol/L pO2 74.7 mmHg (FiO2 0.8) Cl 110 mmol/L HCO3 17.3 mmol/L  Glucose 7.7 mmol/L Lactate 4.3 mmol/L [expand title=”Interpretation”]   What is the pH? 7.18 = acidaemia What […]

Describe and interpret this venous blood gas: History: A 40-year-old man with history of alcohol misuse, abdominal pain and vomiting. He has recently commenced metformin. pH 7.51 Na 132 mmol/L pCO2 18 mmHg K 4.2 mmol/L HCO3 12 mmol/L Cl 88 mmol/L Lactate 5 mmol/L Glucose 20 mmol/L [expand title=”Interpretation”]   What is the pH? 7.51 = alkalaemia What is the primary […]

Describe and interpret this arterial blood gas: History: A 41-year-old man presents unconscious with pinpoint pupils. Paramedics have administered naloxone with a partial response, however his GCS remains 8 on arrival to the emergency department. His arterial blood gas is as follows. pH 7.02 Na 140 mmol/L pCO2 105 mmHg K 3.2 mmol/L pO2 33 mmHg (FiO2 0.6) Cl 108 mmol/L […]

Describe and interpret these blood gases: History: 38-year-old woman post-PEA cardiac arrest, intubated and ventilated. History of major depression and alcoholic liver disease. Venous blood gas on arrival to the ED: pH 7.33 Na 116 mmol/L pCO2 30 mmHg K 2.3 mmol/L pO2 308 mmHg (FiO2 1.0) Ca 0.88 mmol/L HCO3 16 mmol/L Cl 61 mmol/L  Albumin 26 g/L Glucose 9.0 mmol/L Hb 104 g/L […]

  1. What is the pH? Identifies the primary acid base disturbance Acidaemia exists if pH <7.35 Alkalaemia exists if pH > 7.45  If pH is between 7.35 and 7.45 then there is either: No acid base disorder A compensated disorder (can never overcompensate) A mixed disorder  2. Is the primary process respiratory, metabolic or both? Check pCO2 and HCO3 If […]