Case #3 A 76-year-old man complained to his wife of severe sub-sternal chest pains that radiated down the inside of his left arm. Shortly afterward, he collapsed on the living room floor. Paramedics arriving at his house just minutes later found him unresponsive, not breathing, and without a pulse. CPR and electroconvulsive shock were required to start his heart beating again. Upon arrival at the Emergency Room, the man started to regain consciousness, complaining of severe shortness of breath (dyspnea) and continued chest pain. On physical examination, his vital signs were as follows: Blood pressure 85 mm Hg/50 mm Hg Heart rate 175 beats/minute Respiratory rate 32 breaths/ minute Temperature 99.2°F His breathing was labored, his pulses were rapid and weak everywhere, and his skin was cold and clammy. An ECG was done, revealing significant “Q” waves in most of the leads. Blood testing revealed markedly elevated creatine phosphokinase (CPK) levels of cardiac muscle origin. Arterial blood was sampled and revealed the following: pH 7.22 pCO2 30 mmHg po2 70 mm Hg Hemoglobin-O2 saturation 88 % [HCO3- 2 mEq/ liter What is the diagnosis? What evidence supports your diagnosis? (Hint: something other than the acid-base problem). How would you classify his acid-base status? What specifically caused this acid-base disturbance? A. B. C. How has his body started to compensate for this acid-base disturbance?