Injuries are the leading cause of death among children and adults between the ages of one and 44 years, according to the Centers for Disease Control and Prevention. Improving access to trauma centers is, therefore, an essential component of patient survival—as is receiving the correct care at the right time. Two new sets of research suggest a need for changes in care during the time between the occurrence of an injury and arrival at the hospital.
IN-FIELD FLUIDS MIGHT NOT BENEFIT PATIENTS
In a retrospective analysis published in the February issue of the Annals of Surgery, Haut and colleagues examined mortality rates among 776,734 trauma patients from the National Trauma Data Bank, about half (49.3%) of whom had received IV fluids before reaching the hospital. The unadjusted mortality rate in those patients who received IV fluids was significantly higher than in those who didn't—4.8% versus 4.5%, respectively, a difference that translated to more than 2,000 more deaths among those receiving prehospital fluids. Likewise, multivariable analysis showed that those who received fluids (and particularly those with penetrating injuries) were significantly more likely to die.
The authors of the study concluded that routine administration of IV fluids in all trauma patients should be discouraged, noting that "in no subset of trauma patients [was] there a survival advantage for prehospital IV placement." (Although no survival advantage was seen in patients with blunt trauma, no disadvantage was seen, either.)
The dangers of 'popping the clot.' According to the study authors, one theory of the mechanism behind the harm IV fluids appear to cause is that of "popping the clot." As the authors write, "The concept . . . is based on the idea that [in] patients with uncontrollable sources of bleeding such as solid organ injury . . . or other internal bleeding vessels," the clot may "pop" if "the blood pressure is raised before sites of hemorrhage have been controlled," and bleeding may begin anew.
However, Cynthia Saunders, BSN, RN, CEN, CPEN, CMSRN, the trauma coordinator at Antelope Valley Hospital in Lancaster, California, pointed out that the study data weren't derived from prehospital settings, and the causes of hypotension in the trauma patient can vary considerably.
"Hypotension isn't always the result of hypovolemia caused by severe blood loss," she said. "Hypotension can be caused by obstructive shock, such as cardiac tamponade and tension pneumothorax, or a distributive shock, such as spinal or neurogenic shock. It's often difficult to differentiate what's actually going on with a patient, especially one who has suffered blunt trauma, where there may be no visible external bleeding."
Delays in care. Another hypothesis is that the placement of an IV line can delay transport to an ED or trauma center. Placing a venous line is associated with increased time at the trauma scene, according to the study authors, who cite research showing that "in some cases the time to place an IV exceeds that of the actual transport itself."
Gwyn Parris-Atwell, MSN, FNP-BC, CEN, an NP and the immediate past president of the New Jersey Emergency Nurses Association, noted that there are many variables to consider.
"I believe the practice of fluid resuscitation remains a balancing act and depends on how long it takes to get the patient to definitive care [the completion of recommended treatment]," she said. "As a general rule, all prehospital care personnel typically follow a guideline of no longer than 10 minutes' on-scene time, and that time is typically used to get the patient from the scene to the vehicle of transport."
Parris-Atwell said she believes that the study findings need to be considered in the context of specific settings, and that the many differences in local policy, the proximity of the injury scene to a hospital or trauma center, the hospital's capabilities, and even the capabilities of emergency medical personnel must be taken into consideration.
Saunders agrees that there must be some leeway.
"Times to definitive care vary greatly, and geographical areas, mode of transportation, expertise of the field-level rescuer, weather, and traffic are just a few of the things that can impede arrival" at the ED, she said.
"Although this study shows promise in decreasing the mortality rate in critically injured patients, more research needs to be conducted to be able to identify those patients who benefit from the 'scoop and run' approach" (getting the patient to the hospital as quickly as possible, without waiting for lines to be placed), she said. "Many trauma patients have survived because of that approach, but at this time I don't feel that it should be a generalized practice."
In the July 2010 issue of the Lancet, researchers published the results of a long-term study of the use of tranexamic acid (also known as TXA) in more than 20,000 adult trauma patients at 274 hospitals in 40 countries. It was already known that surgical patients who receive tranexamic acid experience less blood loss than those who don't, and the researchers wondered whether tranexamic acid would have the same benefit in trauma patients. Their large, multinational study showed that it did: the CRASH-2 trial demonstrated that tranexamic acid does indeed significantly lower the mortality rate in trauma patients, particularly from hemorrhage, and the authors suggested that "the option to use tranexamic acid . . . be available to doctors treating trauma patients in all countries" and "be considered for inclusion on the [World Health Organization] List of Essential Medicines."
A follow-up study by the same researchers using the same data (published in the March 26 issue of the Lancet) revealed that the earlier a trauma patient with severe hemorrhage receives tranexamic acid, the better. The best results were in patients who received it within an hour of injury, with those receiving it within three hours also showing a lower risk of dying. Surprisingly, those who received it after three hours had an elevated risk of dying. The authors believe that if late administration of tranexamic acid does cause harm, "this finding would be important since many bleeding trauma patients in low-income and middle-income countries have long prehospital times." An invited commentary on the follow-up study noted that "[f]ar less clear is the place for tranexamic acid in high income countries where massive transfusion protocols incorporate fresh-frozen plasma that contains all the endogenous antifibrinolytic elements in plasma," adding, "it is unlikely that many clinicians in major trauma centres will choose tranexamic acid as first-line treatment." That doesn't mean that it won't be useful in prehospital settings, however.
The CRASH-2 authors also conducted a review of studies elucidating the role of antifibrinolytics in trauma care for the Cochrane Injuries Group (published in the January 19 issue of the Cochrane Database of Systematic Reviews) but found only two studies of tranexamic acid that met its criteria for inclusion, one being their own 2010 CRASH-2 study; the other was a small study that didn't have the power to affect the results of the much larger study. The lead author of the review, Ian Roberts, MB BCh, PhD, professor of epidemiology and public health at the London School of Hygiene and Tropical Medicine, told AJN that because tranexamic acid is highly cost-effective in low, middle, and high-income settings, he "would give it as soon as possible, and yes, even prior to the hospital."
The review authors noted that because tranexamic acid "reduces mortality from haemorrhage by about one sixth," it could prevent more than 70,000 deaths annually if it was "used world-wide in the treatment of bleeding trauma patients."
Saunders added a note of caution to the prospect of routine administration of tranexamic acid before arrival at the hospital, pointing out that, as with IV fluids, its administration in the field could also increase time from injury to definitive care because of the need to place an IV.
Parris-Atwell said that the CRASH-2 study is promising, but that more data are needed and best practices must be determined. Prehospital personnel and clinicians who aren't at trauma centers must be diligent about looking for signs of hypoperfusion, she said.
"Ideally, they should recognize traumatic shock before hypotension develops and provide appropriate management according to their skill level," she said. "I do believe that the debate will continue and that the issue will remain controversial for some time."—Roxanne Nelson
© 2011 Lippincott Williams & Wilkins, Inc.