Case Study:
65-year-old female with a history of cardiovascular disease, diabetes, and 30 pack-year history of smoking is being admitted. She had no fever, chills, change in her chronic cough or dyspnea. She was able to participate in her rehabilitation activities and was progressing as expected. On the day of admission, the patient complained of acute onset of dyspnea. She was found to be tachypneic and cyanotic with a respiratory rate of 38. The exam revealed crackles on the right and diminished breath sounds on the left. She was transferred to the closest hospital where she was emergently intubated and transferred to the regional medical center.
The patient became hypotensive shortly after intubation and a continuous infusion of dopamine was started. A pulmonary angiogram was negative for pulmonary embolism (PAP 50/25 mm Hg) and an echo revealed normal LV and RV systolic function with no pericardial effusion. Mechanical ventilator settings for the first several hours of her hospitalization, and during transport were as follows:
Time | Rate | Tidal Volume | FIO2 | PEEP | pH | pCO2 | pO2 |
15:33 | 22 | 300 | 1.0 | 0 | 7.16 | 84 | 290 |
16:16 | 24 | 300 | 1.0 | 0 | 7.13 | 93 | 513 |
17:30 | 40 | 300 | 1.0 | 0 | 7.05 | 105 | 178 |
20:28 | 40 | 320 | 1.0 | 0 | 7.06 | 113 | 483 |
21:00 | Rapidly bagged during transport | 7.01 |
Instructions:
This case study provides you a framework to discuss how you understand the physiology of the heart and physiologic changes associated with disease. Use the cardiac cycle diagram, as a guide, to identify with the concepts that add work to the heart.
- Describe, from your readings, what you understand to be occurring to this patient's heart pre and post intubation.
- Using the cardiac cycle diagram, describe one change that might occur due to the physiologic changes in the case study and why?
- How might oxygen consumption by the heart change in the case study?