Case 3
Brenda Williams is a 73 year old retired seamstress. She is achain smoker. When her employer announced that smoking would nolonger be allowed in the store, she retired. Since her retirement,Mrs. Williams has not been feeling well. She fatigues easily, evenwith light exertion. She has dyspnea and recently has begun tosleep on two pillows.
Early this morning, Mrs. Williams woke up with severe dyspneaand called 911. EMTs found her alert and oriented, and insignificant respiratory distress. Her skin was pale with cyanoticnail beds, cool, and moist. Her pulse was 112, regular, and strong.Her respirations were 26, regular rhythm and depth, and labored.She had an increased anteroposterior chest diameter and audibleexpiratory wheezes. Blood pressure was 128/85. SpO2 was 83%. Theynoted pitting edema of her ankles. She denied chest pain. They puther on oxygen and transported her to the emergency room.
Her physician noted a long expiratory phase in her breathing.Based on this observation, her history, and her vital signs, heordered the following tests:
Pulmonary function tests:
Vorced Expiratory Capacity (FEV1): reduced Residual volume:increased
Laboratory values:
Hemoglobin 14.5 g/dL (normal 12-15 g/dL) Arterial PO2 48 mmHg(normal 100 mmHg) O2 saturation 86% (normal 98-100%)
Arterial PCO2 69 mmHg (normal 40 mmHg) HCO3-: 34 mEq/L (normal 24mEg/L)
pH: 7.31
The physician concludes that Mrs. Williams has a combination ofemphysema and chronic bronchitis, called chronic obstructivepulmonary disease.
Questions:
9. Explain why Mrs. Williams was in respiratory distress.
10.Explain the physiological reasons for the signs that the EMTsassessed (skin, pulse, respiration, anteroposterior chest diameter,blood pressure, pulse oximetry, and pitting edema).
11.Explain the physiological reasons for each of her testresults (both pulmonary and laboratory).
12.Which acid-base disorder does she have? What is the cause?What is the compensation? How does this alter oxygen delivery tothe tissues?
13.Explain why her hemoglobin was normal but her SpO2 and herarterial PO2 were low. Should these tests have similaroutcomes?
