Trauma Resuscitation of the Elderly Patient

This article is the fifth in a continuing series on trauma care and the older adult. The series discusses the growing problem of trauma in the elderly, including its causes and possible ways to prevent it, care in the acute stages, and manifestations and treatment strategies when trauma involves the torso, spine, brain, and hip. Authors include skilled experts in the trauma field representing various specialties at the R Adams Cowley Shock Trauma Center at the University of Maryland Medical Center and the University of Maryland School of Medicine.
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Introduction

Within the last 100 years, the elderly population has experienced the fastest rate of growth in the United States. From 1900 to 1994, the number of Americans age 65 and older increased elevenfold from 3 million to 33 million. By 2050, it is expected that this number will increase to 80 million.¹ The prevalence of active, elderly Americans has had a profound impact on the American healthcare system, and trauma is certainly no exception. Unlike the conventional disease processes that affect the geriatric population, trauma has a unique and complex pathophysiology that significantly increases an elderly patient’s morbidity and mortality as compared to a younger patient. With this in mind, physicians must be able to properly identify and triage the elderly trauma patient, recognize the shock state that may not be apparent at bedside evaluation, and resuscitate the patient to proper end points so that potential complications are minimized.

Diagnosis and Treatment

Adequate resuscitation of the trauma patient begins with appropriate triage. We define triage as the practice of prioritizing care based on the patient’s injuries and the available medical resources. Studies have demonstrated that the elderly trauma patient often experiences undertriage, when the patient’s injuries are underestimated by the medical system, and the patient is transferred to a facility that does not have the essential resources required for definitive care. Multiple institutions have examined this trend in geriatric trauma care, with the conclusion that there is a tendency to undertriage elderly patients because their underlying comorbidities and decreased physiologic reserve are not appreciated.² For instance, blood pressure and heart rate may not be the most sensitive indicators of physiologic distress in the elderly patient, given a likely history of hypertension and beta blockade use. These typical physiologic parameters are less reliable in the pre-hospital evaluation of the elderly patient and, as a result, an occult shock state may go unrecognized. This concept is clearly illustrated by Phillips et al,³ who examined a state-wide trauma system’s criteria for triage and its outcomes among the elderly trauma population. The Florida Trauma Triage Study demonstrated an undertriage rate of 71% when pre-hospital staff used standard physiologic criteria in the assessment of trauma patients older than age 55 years.³ In addition, the study found that the older the patient, the higher the rate of undertriage, with patients older than age 85 years experiencing an undertriage rate of 82%. The majority of injuries included motor vehicle accidents and low-velocity falls; however, the trends illustrate that a seemingly stable geriatric patient is more likely to have significant physiologic abnormalities that are subtle and may be appreciated only by evaluation of specific resuscitation end points.

With patterns of field triage in mind, one should also consider whether there should be a preferential transfer of elderly trauma patients to designated trauma centers. Meldon and colleagues⁴ performed a cohort retrospective study examining elderly patients over age 80 who were treated at Level I and Level II trauma centers versus those treated at local acute care hospitals. Those patients who were severely injured and treated at a designated trauma center had a mortality rate of 8%, whereas patients with similar injuries treated at an acute care hospital had a mortality of 56% (P < 0.01).⁴ Further evaluation revealed that lack of trauma center verification was an independent risk factor associated with increased mortality.

With this in mind, one may conclude that the threshold for triage to a trauma center should be lower for elderly patients because they have less physiologic reserve and more pre-existing medical conditions, thereby raising the acuity of even minor injuries. Demetriades et al⁵ examined this particular idea when they compared elderly patients who met traditional trauma team activation triggers to those who did not meet such criteria. Of the 883 patients over the age of 70 years who were included in the study, 25% met at least one trigger for trauma team activation. Of the 75% of patients who did not have a trigger, there was an Intensive Care Unit admission rate of 24% and a mortality of 16%. Further data analysis showed that 63% of elderly patients with severe injuries did not have any of the hemodynamic parameters that would typically result in trauma team activation. As a result, the authors concluded that advanced age alone should be considered as an independent trigger for team activation.⁵

Once the patient arrives to the trauma center, successful resuscitation depends upon prompt injury diagnosis and early reversal of shock. As stated earlier, the geriatric trauma patient poses an additional challenge secondary to occult hypoperfusion where seemingly normal hemodynamics are not sufficient to provide adequate end-organ perfusion. In light of this, our focus here will reside with how to best identify occult hypoperfusion and correct it using appropriate end points of resuscitation.

Detecting hypoperfusion relies upon invasive monitoring of blood pressure and cardiac function. This can be accomplished by placing an arterial line and central venous catheter, as well as performing early patient screening for pulmonary artery catheter insertion. With the appropriate monitoring devices that are available today, the first two modalities can provide information regarding cardiac output, stroke volume variation, and central venous pressure. An arterial line alone can be connected to a commercially available sensor that can provide cardiac output and cardiac index via an algorithm that detects variation in vascular compliance. In addition, this same device can measure stroke volume variation, which may help delineate a patient’s response to fluid resuscitation.⁶ The early literature on this technology shows that it provides fairly accurate cardiac output values as compared to the pulmonary artery catheter, and can be used to track relative trends in cardiac function.⁷ While its use has steadily declined in the last 20 years, the pulmonary artery catheter still has a role for some elderly trauma patients. Friese and colleagues⁸ reviewed over 53,000 patients within the National Trauma Data Bank and found that patients age 61-90 years with an initial base deficit of -11 and an elevated Injury Severity Score had a decrease in the risk of death with use of the pulmonary artery catheter. Early-guided resuscitation with prompt recognition and treatment of cardiac dysfunction were the key components behind this study’s findings, and this validates the use of pulmonary artery catheters in elderly patients with known cardiac disease or risk factors. Scalea et al⁹ compared elderly trauma patients who appeared clinically stable after initial resuscitation and underwent early-invasive monitoring with historical controls, and found that 43% of patients were actually in cardiogenic shock despite normal initial vital signs. The study went on to show that early-invasive monitoring led to earlier therapeutic interventions and reduced mortality by half.⁹

After detecting cellular hypoperfusion, the clinician should proceed with resuscitative efforts until the shock state is reversed. Among trauma patients, hypovolemic shock remains the most common type of shock, and a goal-directed fluid resuscitation strategy reverses hypoperfusion while minimizing the complications associated with fluid overload. This is best accomplished by using end points of resuscitation. Heart rate, blood pressure, and urine output have been recognized as clinical end points of resuscitation; however, we know from the literature that these parameters are often unreliable secondary to factors mentioned above: the use of beta blockers; a history of hypertension; and pre-existing organ dysfunction. The best evidence emphasizes that base deficit and lactate levels can offer the most specific information regarding tissue perfusion and cellular oxygenation. On admission, these laboratory values provide insight as to the degree of shock and should be used to trend the progress of resuscitation.

Davis and colleagues¹⁰ performed a retrospective review of 2954 patients admitted to a Level I trauma center and found that a base deficit of less than -6 predicted transfusion of blood products within 24 hours of admission. Secondly, the incidence of coagulopathy and multiorgan system failure increased with a worsening base deficit.¹⁰ As for elderly blunt trauma patients, Callaway et al¹¹ discovered that normotensive patients who arrived to the hospital with an initial lactate of greater than 4 had a 4.2 increased odds of death and a 4.1 increased odds of death with a base deficit of less than -6. Each lab value was associated with an inpatient mortality rate of 60%.¹¹ When these markers of hypoperfusion are corrected within 24 hours of admission, patient survival goes up significantly as compared to those who continue to have an elevated lactate after 24 hours. Abramson and colleagues¹² demonstrated this concept when they examined resuscitation practices involving severely injured trauma patients. Those who had a normal lactate level within 24 hours of initial presentation survived, whereas patients who maintained an elevated lactate level between 24-48 hours of presentation had a mortality of 25%. Furthermore, if the lactate level remained elevated beyond 48 hours of presentation, mortality was 86% among this group.¹² These data illustrate that cellular markers of anaerobic metabolism can offer the clinician specific insight into the degree of hypoperfusion that persists within a patient with seemingly normal vital signs. Using base deficit and lactate as end points of resuscitation will not only allow one to trend resuscitative efforts, but they may ultimately help prevent the detrimental effects of overresuscitation.

Conclusion

The elderly trauma patient presents a challenging clinical dilemma to any clinical team. Multiple comorbidities, decreased physiologic reserve, and the incidence of occult hypoperfusion often make the chance for a successful functional outcome less likely. In order to overcome these challenges, the clinical team must understand that timely diagnoses and treatment is the key. Proper triage, prompt recognition of shock, and close monitoring will make the difference and will allow up to 85% of elderly patients the ability to return to their pre-existing functional level.¹³

The authors report no relevant financial relationships.

Dr. Rushing is Surgical Critical Care Fellow, and Dr. Scalea is Physician-in-Chief, R Adams Cowley Shock Trauma Center, Francis X. Kelly Professor of Trauma Surgery, and Director, Program in Trauma, University of Maryland School of Medicine, Baltimore. Dr. Gambert is Professor of Medicine and Co-Director, Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Maryland School of Medicine, Director of Geriatric Medicine, University of Maryland Medical Center and R Adams Cowley Shock Trauma Center, and Professor of Medicine, Division of Gerontology and Geriatric Medicine, Johns Hopkins University School of Medicine, Baltimore, MD. Dr. Stein is Chief of Critical Care, R Adams Cowley Shock Trauma Center, and Associate Professor of Surgery, Department of Surgery, University of Maryland School of Medicine.

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