Mrs. S. has been brought to the emergency department (ED) with increasing shortness of breath, coughing, and mild substernal pressure. Her husband called the paramedics when she complained she "cannot breathe." Mrs. S. is currently on a Venturi mask with an inspired oxygen fraction ([tex]FiO_2[/tex]) of 0.50. Her husband states she is a 66-year-old housewife with a history of coronary artery disease, arrhythmia, and a recent hospitalization for 3 weeks due to an anterior wall myocardial infarction (MI); she has been out of the hospital for a month.

Physical examination reveals:
- Heart rate: 158 beats/min
- Blood pressure: 110/70 mm Hg
- [tex]SpO_2[/tex]: 93% on the Venturi mask
- Breath sounds: Inspiratory crackles from the bases up to the mid-chest, mild expiratory wheezes
- Respiratory rate: 34 breaths/min with some paradoxical respirations
- Pitting edema: Present in the ankles
- Skin: Cool and diaphoretic
- Jugular vein distention: Noted

Mrs. S. has been admitted to the cardiac care unit. A portable chest radiograph taken on admission in the ED reveals cardiomegaly, as well as bilateral pulmonary vascular engorgement with interstitial and alveolar edema. She is diagnosed with congestive heart failure.

1. What drug would be beneficial in helping remove fluid from the patient's lungs?

2. Thirty minutes after giving 40 mg of Lasix, diuresis has not occurred. What would you now recommend?

It has been 2 hours since Mrs. S. was admitted to the cardiac care unit. She is resting more comfortably and is on a nasal cannula at 3 L/minute. Because of the medications she is currently receiving, laboratory tests are obtained with the following results:
- Potassium: 2.5 mEq/L (normal: 3.5-5.0 mEq/L)
- Sodium: 140 mEq/L (normal: 136-145 mEq/L)
- Chloride: 87 mEq/L (normal: 95-105 mEq/L)
- Glucose: 125 mg/dL (normal: 90-150 mg/dL)

3. Based on this finding, what would you recommend?

4. What acid-base imbalance is likely to occur with these chemistry results?