EMTs accurately identify patients with ST-elevation myocardial infarction (STEMI) in 85 percent of cases, according to data from a statewide STEMI network. A study of 4,000 patients found that only 6 percent of cath lab activations were canceled when hospital staff interpreted the ECG differently than responders involved in the call. (Even emergency room physicians weren’t immune to reinterpretation; about 4.6 percent of ECGs they read were reinterpreted by cardiologists.) Other cath lab activations were canceled because the patient wasn’t appropriate for catheterization, such as if he had a terminal illness or a DNR or was over age 90.
Guidelines from the American Heart Association and the American College of Cardiology recommend a door-to-balloon time for out-of-hospital STEMI patients of less than 90 minutes, and having prehospital personnel able to do ECGs is a key part of this, according to researchers from Carolinas Medical Center in Charlotte, N.C., and colleagues.
The study is in the Jan. 17 issue of Circulation.
CPAP Using Less Than 100% Oxygen Effective
Use of continuous positive airway pressure (CPAP) devices with 28 percent to 30 percent oxygen—instead of the much higher concentrations that are typical—is effective in the prehospital setting, finds a study published online Dec. 16, 2011, ahead of print in the April/June issue of Prehospital Emergency Care.
Evidence is building that oxygen delivery can have downsides, including hyperoxia, which occurs when too much oxygen decreases coronary blood flow and causes oxidative damage to cell membranes, according to background information in the study. However, CPAP is useful in the prehospital setting, offering a non-invasive means of ventilation assistance that research has shown to be cost-effective and reduces the need for intubation.
In the study, responders from MedicWest Ambulance in North Las Vegas and AMR in Las Vegas used CPAP devices with 28 percent to 30 percent oxygen on 340 prehospital patients in respiratory distress because of congestive heart failure/acute pulmonary edema, chronic obstructive pulmonary disease, asthma and pneumonia. According to EMS assessments, nearly 72 percent of the patients improved, 15 percent stayed the same, and 13 percent deteriorated. Only 5.6 percent required prehospital intubation. After 15 minutes of CPAP, oxygen saturation rose from 81 percent to 94.2 percent, and respiratory rate went from 34.5 breaths per minute to 27.9 breaths per minute.
The research team was led by Bryan Bledsoe. D.O., of the University of Nevada School of Medicine.
