Upbeat advances in critical care and emergency nursing

Nursing, Jan 2002 by Woods, Anne, Williamson, Cheryl, Day, Michael W, Arbour, Richard

FROM BIPHASIC BREAKTHROUGHS TO SIMPLIFIED PROGRAMMING MECHANISMS, THESE ARE THE LATEST TECHNOLOGY OPTIONS.

The latest technology in cardiac care units and emergency departments is designed to be easier on the patient and the caregiver. For example, pacemakers and defibrillators continue to decrease in size even as they grow in efficacy. Simplified programming and other user-friendly features save you time and improve the quality of care. And several nontechnologic devices are helping to improve patient care and save nursing time.

Here's a rundown of some of the exciting new advances that are transforming critical care and emergency nursing.

Biphasic breakthroughs

Defibrillators using a biphasic method offer lower-- energy, self-reversing waveforms to correct arrhythmias. Earlier technology employs high-energy, single-direction (monophasic) electrical charges across the chest.

Studies show that biphasic waveforms are more accurate than monophasic waveforms. Their lower voltage and current help decrease the incidence of postshock myocardial dysfunction.

Professional defibrillators use one of two biphasic waveforms:

* biphasic truncated exponential (BTE) waveforms. BTEs use a truncated current flow before returning to baseline. These waves vary in shape and performance.

* rectilinear biphasic waveforms. These waveforms, which have a fixed shape, provide a constant current during their first phase. This eliminates adverse effects related to high peak currents, such as myocardial injury.

Besides lower energy, biphasic devices offer such advantages as a smaller size and lighter weight, lower cost, longer battery life, and fewer maintenance requirements than monophasic devices.

Enhanced extemal counterpulsation

An alternative treatment for chronic angina and heart failure, enhanced external counterpulsation is designed for patients who aren't candidates for invasive therapies, such as percutaneous coronary interventions or coronary artery bypass graft surgery, or for those whom other therapies have failed. For more details, see "Enhanced External Counter Pulsation: Beating Angina" in the October issue of Nursing 2001.

Vascular hemostasis devices

These devices improve patient outcomes and reduce costs associated with cardiac catheterization and catheter-based cardiac interventions. They include:

* absorbable bovine collagen plugs inserted at the arterial puncture site

* physician-placed sutures around the puncture site in the femoral artery

* collagen sponges and absorbable polymer anchors. Hemostasis occurs when the arterial puncture site is sandwiched between the anchor and the sponge.

These devices achieve hemostasis quicker than traditional compressive methods, allow patients to ambulate sooner, require less nursing time, and cause fewer vascular and bed-rest complications.

More exciting news

Other advances include:

* ST-segment monitors. Crucial for patients with acute coronary syndrome, these noninvasive, continuous cardiac monitors let caregivers differentiate between cardiac ischemia and infarction. Caregivers can set ST-segment monitors to perform electrocardiograms at regular intervals or when changes in the patient's pain occur.

Continuous ST-segment monitoring can identify silent ischemia (which can occur in women and patients with diabetes) and failed reperfusion, and it can clue you in to whether a patient with unstable angina is progressing to acute myocardial infarction.

* automatic implantable cardioverter-defibrillators.

These devices are available with single and dual chambers, both with built-in pacemakers. The dual-chamber device has two leads for pacing both the ventricles and the atria. Besides pacing both chambers, the latest devices can defibrillate the ventricles and cardiovert the atria. Caregivers can program them to track activity before, during, and after an arrhythmia and print out the results.

* implantable loop recorders. Implanted in a patient's chest, these devices track arrhythmias over a longer time with less inconvenience to the patient than a 24-hour Holter monitor. They're activated by the wearer when she has symptoms. Implantable loop recorders are appropriate when Holter monitors have been used without detecting arrhythmias and the patient still has symptoms.

* wrist blood pressure cuffs. Worn by the patient, these cuffs compress the radial artery to determine blood pressure and also give the clinician an arterial waveform.

* intraosseous infusion devices for adults. In adults who've suffered trauma, cardiopulmonary arrest, or peripheral vein collapse for any reason, these devices provide a rapid alternative to intravenous (I.V.) access. Delivering I.V. medications and other fluids, they can stay in place for up to 24 hours or until caregivers establish IN. access.

* bispectral index (BIS) monitoring. Advances in BIS-which is based on electroencephalograph technology-let clinicians measure and track a patient's level of consciousness, helping to ensure that the proper amount of anesthesia and sedation is administered. Monitoring electrodes attach to the patient's forehead. The BIS monitor can be used in the operating room or in intensive care units and is especially helpful with patients receiving neuromuscular blockade.