Accessory muscles of inspiration

A 62-year-old man had a long history of cough and shortness of breath, coupled with multiple hospitalizations. He was admitted because of severe, worsening dyspnea. He lived and worked in Pittsburgh, Pennsylvania, for 35 years as a foundry
worker in a steel manufacturing plant. His wife died 10 years prior to this report. After his wife’s death, he lived alone for 9 years and managed his daily activities with progressive difficulty.
Approximately 2 years before this admission, he was forced to retire early because of declining health. His doctor told him that he had the chronic obstructive pulmonary disease (COPD). For the past year, he had been living with his brother’s
family in Chicago, Illinois. The patient’s brother indicated during the interview that the patient might “have the flu again.” The patient had a 35-pack/year history of smoking unfiltered cigarettes, but he stopped smoking at the time of his forced
retirement.
His last hospitalization was 9 weeks before this admission. At that time, he was hospitalized for 2 days for cough, muscle aches, and pains, fever, and respiratory distress. He underwent a complete pulmonary function study and received airway
clearance therapy, oxygen therapy, and instruction in at-home breathing exercises. During this hospitalization, hospital personnel noted that the patient’s expiratory flow rate measurements had declined significantly since his pulmonary function tests(PFTs) a year earlier. Bedside, spirometry showed an FEV1/FVC ratio of 43% and an FEV1 of 27% of predicted—GOLD grade 4. The patient’s mMRC was 2 and he now had two exacerbations in the last 12 months—both leading to hospital admission. In fact, in the past year his forced expiratory volume in 1 second (FEV1) had declined from 70% of that predicted to 45% of that predicted. At discharge 9 weeks before this admission and on 1.5 L per minute oxygen by nasal cannula, the patent’s ABGs were as follows: pH 7.37, PaCO2 67 mm Hg, HCO3– 36 mEq/L, and PaO2 63 mm Hg. He had received the influenza vaccine 6 months earlier and the pneumococcal vaccine 2 years earlier.

At the time of discharge 9 weeks earlier, he was demonstrating pursed-lip breathing and using his accessory muscles of inspiration at rest. He demonstrated no spontaneous cough or sputum production. His bronchodilator therapy was discontinued 1 year ago because it had been “found to be ineffective” during his PFT. He was strongly encouraged to perform his pulmonary rehabilitation exercises daily.
A weekly exercise diary was given to him by the respiratory care department at discharge.

PHYSICAL EXAMINATION
In the emergency room, the patient was febrile, cyanotic, and in obvious respiratory distress. He appeared malnourished at 6 feet tall and weighed 66 kg (146 lb). His skin was cool and clammy. The patient said, “I’m so short of breath!”His vital signs were as follows: blood pressure 154/110, heart rate 95 bpm, respiratory rate 25/minute, and oral temperature 38.3C (101F). He was using his accessory muscles of inspiration and breathing through pursed lips. An increased anteroposterior diameter of the chest was easily visible. Percussion revealed that he had a low-lying, poorly mobile diaphragm. Expiration was prolonged, and his breath sounds were diminished. No wheezes were noted, but crackles could be heard over the right lower lobe.
A chest x-ray showed hyperinflation, severe apical pleural scarring, a large bulla in the right middle lobe, and a right lower lobe infiltrate consistent with pneumonia (see the figure below). On instruction, the patient’s forced cough was weak and productive of a small amount of yellow sputum. On 2 L per minute oxygen by nasal cannula, his ABGs were as follows: pH 7.59, PaCO2 40 mm Hg, HCO3– 37mEq/L, and PaO2 38 mm Hg. The physician ordered a pulmonary consult and stated that she did not want to commit the patient to a ventilator if possible. The patient also was started on intravenous doses of methylprednisolone.

2 DAYS LATER
At this time, the patient stated that his chest was feeling tighter and that he was even shorter in a breath. His vital signs were as follows: blood pressure 160/112, heart rate 97 bpm, respiratory rate 15/minute, and shallow and oral temperature 37.8C(100F). Expectorated sputum was thick, yellow, and tenacious. He no longer was using his accessory muscles of inspiration or demonstrating pursed-lip breathing. His breath sounds were diminished bilaterally, and crackles no longer could be heard over the right lower lobe. Dull percussion notes were elicited over the right lower lobe. On 4 L per minute oxygen by nasal cannula, his ABGs were as follows: pH 7.28, PaCO2 82 mm Hg, HCO3– 36 mEq/L, and PaO2 41 mm Hg. His hemoglobin oxygen saturation measured by pulse oximetry (SpO2) was 68%. A repeat chest x-ray showed more extensive pulmonary infiltrates, particularly in the right lower chest. The physician ordered subcutaneous terbutaline every 8 hours.