Case Study - Pulmonary Embolism

Department of Physiology

Ross University School of Medicine


History

A 35 year old white female reports to the Emergency Room because of sharp left sided chest pain and shortness of breath of one day duration. The patient was in excellent health until yesterday. She was awakened from her sleep by sharp left sided chest pain. The pain worsened with motion and deep breathing. The pain has been progressively increasing in severity and she now has severe left shoulder pain. She complains of shortness of breath and is very apprehensive about dying. She denies any cough, fever, sputum production or hemoptysis.

She is married and had one normal delivery three years ago. She is currently on birth control pills. She has never been hospitalized except for labor and delivery. Review of systems are negative. She denies any past history of venous problems.

She reveals having a similar transitory minor episode of chest pain approximately one year ago while she was vacationing in Michigan.

She works as a computer programmer. She smokes one pack of cigarettes a day for the past eight years. She considers herself a social drinker.

Is her pain due to pleural or parietal inflammation?

What are the characteristics of pleural pain?

What is the mechanism of her shortness of breath (dyspnea)?

Physical Examination

    Blood pressure 114/80; pulse 118; temperature 37.0 (oral)

    She appears to be in moderate respiratory distress. She is well developed and nourished. Pertinent findings include a respiratory rate of 30 and shallow breathing. There is dullness, decreased chest expansion and decreased breath sounds in the left base. There is egophony in the left base. There were no rales or rubs.

    Heart reveals PMI in the 5th intercostal space in MCL. The pulmonic component of the second sound is accentuated.

    Abdomen, pelvic and rectal exams are normal.

    The extremities reveal no evidence of edema, cyanosis or clubbing.

    Joint exam revealed shoulder movements complete in range. No warmth or tenderness noted. The rest of the patient's joints are normal.

    The Emergency Room physician orders the following tests:

    CBC: Hgb 15.0; Hct 43; WBC 11,500; 83 polys, 1 band and 14 lymphs

    SMA-12: Normal

    Arterial blood gases: FI02 .21; pH 7.39; PCO2 30; HCO2 20; PO2 80 and SO2 95%

    EKG reveals sinus tachycardia and non-specific S-T-T wave changes axis + 80.

    CXR reveals a small pleural effusion in the left base. The left diaphragm is elevated.

    Shoulder x-ray is normal.

    Interpret the blood gases.

    Calculate the A-a O2 gradient

    What is the mechanism of her shoulder pain?