Thelma Walters is a 77-year-old woman who arrives via EMS at the emergency department after experiencing increasing dyspnoea for the past 2 days. She has also noticed swelling in her feet and ankles. Due to her onset of shortness of breath, she has had to sleep in a recliner and is unable to lay flat in bed at night. Her past medical history includes a myocardial infarction 3 years ago and an episode of heart failure 1 year ago. The heart failure was treated with captopril (Capoten) and furosemide (Lasix), which she has been taking since that time. Her surgical history includes a hysterectomy 20 years ago. She has never used tobacco or alcohol. As the nurse performs the initial physical assessment the following relevant findings are discovered. The patient is 1.7 m (5’6”) tall and weighs 82 kg (180 lb). The patient’s blood pressure is 162/92 mmHg, her heart rate is 148 beats/min and irregular, and her respiratory rate is 38 breaths/min and laboured. The neck veins of the patient are distended when she is placed at a 45-degree incline. She is orthopneic and cannot tolerate the head of the bed being lowered below 45 degrees. The nurse notes scattered crackles bilaterally throughout the lung fields. The patient has a productive cough with frothy, pink-tinged sputum. 4 + pitting edema of both hands and legs is noted with the nail beds moderately cyanotic. Circumoral cyanosis is also noted. Immediately upon arrival at the emergency department, the patient received oxygen therapy and an IV line was started. Blood is collected for initial laboratory data with the following results: serum sodium 136 mEq/L (normal 135–147 mEq/L), serum potassium 3.1 mEq/L (normal 3.5–5.2 mEq/L), and arterial blood gases on room air: pH 7.32, PaO 2 54, PaCO 2 48, SaO 2 68%, indicating overall hypoxemia. Thelma is in acute distress and admitted to the intensive care unit (ICU) with a diagnosis of heart failure. She is given a dose of furosemide (Lasix) 20 mg intravenously and she will receive milrinone (Primacor) by IV infusion after admission to the ICU.
1. Describe how milrinone (Primacor) aids in treating heart failure.
2. During the infusion of milrinone (Primacor), Thelma’s ECG and blood pressure will be monitored closely. What adverse effects does milrinone have on the heart rhythm and blood pressure?
3. Because Thelma has been taking furosemide (Lasix) at home and has received another dose in the emergency department, what will the nurse assess prior to starting the milrinone (Primacor)? What electrolyte imbalance must be corrected before Thelma receives the milrinone (Primacor)?