EMS World

MAR 2015

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EMSWORLD.com | MARCH 2015 43 applied they recommend a hemostatic agent be added to a pressure dressing. Hemostatic dressings must be applied directly to the source of the bleeding in order to work. 17 The Bottom Line If initial direct pressure fails to control hem- orrhage, remove the dressing and apply well- aimed direct pressure onto the hemorrhage location. When this fails, a tourniquet or hemostatic agent should be used. Myth #7: Radial Pulse Means a Systolic Blood Pressure of 80 mmHg; a Carotid Signifes a Systolic Blood Pressure of at Least 60 mmHg The myth explained: The 80/70/60 rule for radial, femoral and carotid pulse points to predict blood pressure has long been taught in both prehospital medicine and Advanced Trauma Life Support courses. The theory states the presence of a radial pulse indi- cates the systolic blood pressure is at least 80 mmHg, and a femoral and carotid pulse then indicate systolic pressures of 70 mmHg and 60 mmHg respectively. The Evidence This myth was challenged in a paper titled "Accuracy of the Advanced Trauma Life Support Guidelines for Predicting Systolic Blood Pressure Using Carotid, Femoral, and Radial Pulses: Observational Study" pub- lished in the British Medical Journal. This paper studied major trauma patients and evaluated their blood pressure when their radial, then femoral, then carotid pulses were lost. Without exception, all patients first lost their radial and then femoral pulses in sequence prior to losing carotid pulses. However, the actual values of these were quite surprising. Eighty-three percent of patients with radial pulses had a systolic blood pressure <80 mmHg (mean 72.5 mmHg), and 83% of patients with femoral pulses (radial absent) had systolic blood pressures <70 mmHg (mean 66.4 mmHg). No patients with only carotid pulses had the predicted blood pressure of >60 mmHg. 18 In another study on critically ill ICU patients where radial and femoral blood pressures can be measured simultaneously, researchers found the mean arterial pres- sure (MAP) at the radial artery provided on average a bias of 4.27 mmHg higher than the femoral; however, nearly a third of the measurements found a bias greater than 10 mmHg. Keeping in mind MAP is calculated by the equation [(2 x diastolic)+systolic]/3, this bias could be a difference in systolic blood pressure that is significantly larger. 19 The authors concluded peripheral readings become falsely high in critically ill patients because of the catecholamine release that occurs as the body tries to compensate dur- ing shock. This further impacts the systolic blood pressure estimation myth by suggest- ing that acutely hemorrhaging patients may have a falsely elevated peripheral pressure as the body tries to compensate for its blood loss; it is important to consider the central pressure may be lower than peripheral blood pressures suggest. The Bottom Line Using the 80/70/60 rule for peripheral puls- es overestimates a hemorrhaging patient's blood pressure and may put them at risk for delayed intervention. Obtain accurate blood pressures. There is a key component of common sense here though—if you can- not feel your patient's radial pulse they are likely to be very hypotensive and ill. Myth #8: The Golden Hour The myth explained: Following major injury, patients have one hour to arrive at a definitive care facility before their chances of death significantly rise. The Evidence Craig Newgard, et al., published a paper challenging the truth of the golden hour in the January 2015 Annals of Emergency Medicine. In their research they evalu- ated trauma patients, 778 of whom were in 1601 W. Deer Valley Road, Phoenix, AZ 85027 • www.knoxbox.com • info@knoxbox.com Knox ® MedVault ® Drug Locker P r o t e c t y o u r D e Pa r t M e n t, S ta f f a n D I n V e n t o r y • neW – Two Sizes Available • Know Who Accessed Narcotics & When • neW – WiFi Remote Administration • Narcotic Access Control & Accountability 800-552-5669 • knoxbox.com r e D u c e e x P o S u r e t o n a r c o t I c S t h e f t For More Information Circle 36 on Reader Service Card

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