USOM I Case 2
64 y/o M with pmhx of CAD, prior PCI, presents with increasing dyspnea on exertion, fatigue, paroxysmal nocturnal dyspnea, and weight gain. Over the last two days he has developed confusion and weakness.
You perform a bedside ultrasound, which reveals the following: Case 2 Ultrasound
What is the diagnosis and what ultrasound findings support this?
Answer
Congestive heart failure, fluid overload state: Pt has a decreased EF (ejection fraction) as evidenced by poor mitral valve excursion toward the septum in the parasternal long view and minimal left ventricular wall motion in the parasternal short axis. There are several methods to determine ejection fraction including using EPSS, Stimpson method, etc…, but studies have shown that visual gestalt is just as effective and accurate (in experienced ED echocardiogram MD interpreters, granted). In a normal EF, the mitral valve will slap against the septum (as seen best in the parasternal long view) and in severe EF, the mitral valve will hardly move as seen in this ECHO. Ventricular wall motion is best seen in the parasternal short view as the entire circumferential wall can be visualized. In this echo, the walls are barely moving, suggesting a severely depressed EF.
This ultrasound also shows B-lines in the lungs, which are detected by using an abdominal probe placed longitudinally on the anterior chest at the mid-clavicular line around the 2nd – 4th intercostal spaces. Generally, if there are >3 B-lines visualized ~7 mm apart between two ribs, then that is suggestive of pulmonary edema (Lichtenstein et al. A-Lines and B-Lines: lung ultrasound as a bedside tool for predicting pulmonary artery occlusion pressure in the critically ill. Chest. 2009, Oct; 136(4):1014-20)
Lastly, this patient has a pleural effusion. An abdominal probe is used on the right flank similar to evaluating the liver and kidney on a fast exam, but moved a bit more cephalad. The liver and diaphragm are easily visualized and a clearly hypoechoic fluid collection is seen above the diaphragm within the pleural space.
All these findings (decreased EF, pulmonary edema, pleural effusion) suggest that this patient has decompensated congestive heart failure and is fluid overloaded.
The lab calls to report a critical value on the patient’s vbg (corroborated on bmp) of a Na+ of 112 (new compared to prior labs)
What type of hyponatremia does this patient have (question 1 of case 1 lists a few of the possibilities)? How do you want to do to treat the patient’s hyponatremia?
Answer
Hypervolemia hyponatremia: CHF results in a fluid overload state but overall hypoperfusion of end organs such as the kidneys, resulting in fluid retention. Treatment for these patients is fluid restriction and ACE inhibitors, although those can be started inpatient and are generally used in refractory cases. The ACE will increase cardiac output and inhibit ADH, ACE also decreases renal water absorption….all beneficial effects in CHF patients with hyponatremia.