19/06/2014
For tomorrow group discussion, the following clinical scenario will be discussed.
A 27-year-old woman presents to the emergency room after 24 hours of right-sided chest pain, which is worse with inspiration. She is short of breath and anxious. The patient denies sputum production, hemoptysis, cough or wheezing but states that she felt warm at home but did not take her temperature. The patient has no prior history of lung or heart disease. She takes oral contraceptives, and has no known drug allergies. She has undergone no surgical procedures. She smokes one pack of ci******es per day, and does not consume alcohol. She denies intravenous drug use and has no risk factors for HIV disease. She works as an accountant. Her family history is negative for asthma and heart disease.
Physical examination reveals an obese woman in moderate respiratory distress. Her temperature is 38°C (100.4°F), her pulse is 115 beats per minute, her blood pressure is 140/80 mm Hg, and her respiratory rate is 26 breaths per minute. No jugular venous distention is observed. Her chest is clear. Cardiac examination reveals regular rate and rhythm, with normal intensity of the first and second heart sounds. There are no third or fourth sounds, murmurs, or rubs. Abdominal examination reveals positive bowel sounds and no hepatosplenomegaly. Her extremities show no cyanosis or edema.
Her laboratory values are as follows: hemoglobin, 14.5 g/dL; hematocrit, 42%; white blood cells, 6,000/mm3 with 74% segmented neutrophils and 26% lymphocytes. Peak expiratory flow is 450 L per minute, which is normal. A chest radiographic study reveals a normal cardiac shadow and clear lung fields, except for a small peripheral infiltrate in the lower left lobe. An electrocardiogram shows sinus tachycardia without ischemic changes. Arterial blood gas measurement performed on room air reveals a pH of 7.49, a PCO2 of 32 mm Hg, a PO2 of 60 mm Hg.
If her body weight is 90kg, TV is 500ml and pulmonary blood flow is 3L/min, assess her ventilation-perfusion ratio
