Quicken treatment for heart failure with BNP test

After suddenly becoming short of breath, a 28-year-old woman in Tuscon, AZ, called 911 and was taken to Carondelet St. Mary’s Hospital’s ED in severe respiratory distress with blood pressure of 250/140. After B-type natriuretic peptide (BNP) testing was done, it was determined the patient was in congestive heart failure (CHF) and nesiritide was given.

"Within five minutes, the patient’s blood pressure was down to 160/110, and she was no longer in respiratory distress. She was admitted to a low-acuity telemetry floor," says Diana Platt Lopez, RN, BSN, clinical educator for emergency services.

Although the woman’s symptoms were indicative of congestive heart failure, the BNP nailed the diagnosis within 20 minutes, says Lopez. "It is even more beneficial in making the diagnosis in elderly patients with complex histories, such as those with a cardiac and pulmonary history," she adds.

Treatment would have been delayed without a clear-cut diagnosis, and the patient may have required intubation, resulting in increased length of stay, intensive care unit admission, and possible complications such as ventilator-associated pneumonia, says Lopez.

As a result of BNP testing, CHF patients are being treated earlier in the ED with nesiritide, says Lopez. "Sorting out if a patient truly has CHF early in their presentation leads to the patient receiving the correct therapy earlier," she explains.

A new report from Plymouth Meeting, PA-based ECRI, a nonprofit health services research agency, provides strong evidence that BNP testing improves outcomes for ED patients with symptoms of heart failure. (To obtain a copy of the report, see resources, below.)

BNP is a cardiac neurohormone that is secreted in response to increased ventricular volume and pressure, and elevated levels can indicate the presence of heart failure, says Lopez. "This is a quick blood test that results in an accurate diagnosis and a more expeditious application of proper treatment," she explains.

Faster diagnosis, faster treatment

Early identification of heart failure can significantly improve outcomes, says Michele Gilbert, RN, BSN, CCRN, CNN, education coordinator for the heart failure program at Hackensack (NJ) University Medical Center, where a recent study assessed the impact of BNP testing on clinical outcomes, including time to symptomatic relief and length of stay.

In a study of 100 patients, with 50 admitted to the hospital before the use of BNP and 50 admitted after the use of BNP, there was a 34% reduction in time until symptomatic relief and a 39% reduction in length of stay when the BNP assay was used.1

The laboratory has the BNP test results back within an hour, which enables ED staff to quickly provide correct and timely treatment to CHF patients, says Gilbert. "This translates into better, more focused care, quicker relief of symptoms, and cost savings through shorter length of stay and the avoidance of unnecessary treatment."

Use of BNP testing can help you determine if a patient is in heart failure, or if their symptoms are caused by isolated pulmonary, renal, or venous problems, says Sonja D. Brune, RN, MSN, CCRN, CCNS, staff nurse in the transplant intensive care unit at San Antonio-based Christus Santa Rosa Medical Center Hospital and former cardiovascular clinical nurse specialist at Central Cardiovascular Institute of San Antonio.

"Keep in mind, however, that renal disease, and to some degree, pulmonary disease, can cause a slight increase in BNP levels," says Brune. "Rarely are patients with [end-stage renal disease] going to have normal BNP levels." Conversely, obese patients have lower BNP levels than normal-weight patients, so even moderate increases may be of more clinical significance, adds Brune.2

In addition, the absence of crackles in lung fields does not exclude pulmonary edema, advises Brune. "Many patients with chronic heart failure have clear breath sounds even in the presence of elevated cardiac filling pressures resulting in fluid volume overload."

At St. Mary’s ED, when diuretics don’t appear to be working, patients are given nesiritide and avoid intubation, says Lopez. Nesiritide has been effective for hemodialysis patients who present short of breath and in need of dialysis, she adds. "We have averted intubation with a few of these patients by using nesiritide as a bridge’ to alleviate their symptoms until the patients can be given a dialysis treatment," says Lopez.

Brune gives the example of a young, healthy patient who presented with shortness of breath after a viral syndrome and was treated with antibiotics for a presumed upper respiratory infection, but the patient returned to the ED when symptoms worsened. At that point, an echocardiogram revealed that an ejection fraction of 20%, indicating significant left ventricular systolic dysfunction.

"While this scenario is not seen in epidemic proportions, it is not an isolated event either," says Brune. "A BNP level most likely would have signaled a decline in left ventricular function at the initial presentation and could have triggered more aggressive treatment for suspected viral cardiomyopathy, thus improving the long-term outcome of this patient."

References

1. Abstract. Presented at: The 7th Annual Scientific Meeting of the Heart Failure Society of America. Las Vegas; September 2003.

2. Mehra MR, Uber PA, Park MH, et al. Obesity and suppressed B-type natriuretic peptide levels in heart failure. J Am Coll Cardiol 2004; 43:1,590-1,595.

Sources/Resource

For more information about B-type natriuretic peptide testing, contact:

  • Michele Gilbert, RN, BSN, CCRN, CNN, Education Coordinator, The Heart Failure Program at Hackensack University Medical Center, 20 Prospect Ave., Suite 201, Hackensack, NJ 07601. Telephone: (201) 996-2934. Fax: (201) 996-5703. E-mail: mgilbert@humed.com.
  • Diana Platt Lopez, RN, BSN, Clinical Educator, Resource Clinician, Emergency Services, Carondelet St Mary’s Hospital, 1601 W. St. Mary’s Road, Tucson, AZ 85745. Telephone: (520) 740-6193. Fax: (520) 872-6641. E-mail: dplopez@carondelet.org.

The report, B-Type Natriuretic Peptide for Diagnosing Heart Failure, sells for $750 including shipping. To purchase a copy, contact ECRI, 5200 Butler Pike, Plymouth Meeting, PA 19462-1298. Telephone: (610) 825-6000, ext. 5170. Fax: (610) 834-1275. E-mail: dcummins@ecri.org. Web: www.ecri.org.