Geriatric Trauma: Parameters for Resuscitation

Authors

Jacobs, David G. MD; Plaisier, Brian Ray MD; Barie, Philip S. MD; Hammond, Jeffrey S. MD; Holevar, Michele R. MD; Sinclair, Karlene E. MD; Scalea, Thomas M. MD; Wahl, Wendy MD; for the EAST Practice Management Guidelines Work Group

Author Information

From the Carolinas Medical Center (D.G.J.), Charlotte, North Carolina, Trauma Service, Bronson Hospital (B.R.P.), Kalamazoo, and Trauma Burn Center, University of Michigan Health System (W.W.), Ann Arbor, Michigan, New York Hospital-Cornell Medical Center (P.S.B.), New York, New York, Robert Wood Johnson Medical School (J.S.H.), New Brunswick, New Jersey, Mt. Sinai Hospital (M.R.H.), Chicago, Illinois, Morehouse School of Medicine (K.E.S.), Atlanta, Georgia, and R Adams Cowley Shock Trauma Center, University of Maryland Medical Center (T.M.S.), Baltimore, Maryland.

Address for reprints: David G. Jacobs, MD, Carolinas Medical Center, P.O. Box 32861, Charlotte, NC 28232; email: djacobs@carolinas.org.

Introduction

Advanced age is a well-recognized risk factor for adverse outcomes after trauma. A substantial body of literature, much of it cited within this article, demonstrates increased morbidity and mortality in geriatric trauma patients compared with their younger counterparts. Whether this outcome difference is because of the decreased physiologic reserve that accompanies aging, a higher incidence of preexisting medical conditions in the geriatric patient, or other factors yet to be identified remains unclear. It is clear, however, that good outcomes can be achieved in this patient population when appropriately aggressive trauma care is directed toward geriatric patients with survivable injuries. Implicit in the above statement is the need to identify, as soon as possible after injury, those patients who will benefit from aggressive resuscitation, timely injury management, and posttrauma rehabilitation. It is equally important, however, to limit these intensive and expensive treatment modalities to patients whose injuries are not only survivable but also compatible with an acceptable quality of life.

Our purpose in developing this guideline was to provide the trauma practitioner with some evidence-based recommendations that could be used to guide decision-making in the care of the geriatric trauma patient. We began this process by first developing a series of questions, the answers to which we hoped could be supported by the existing scientific literature. The initial set of questions were as follows:

1. Is age itself a marker of increased morbidity/mortality? If so, what age should be used?
2. Is age instead a surrogate for increased preexisting conditions (PECs)? If so, which premorbid conditions are particularly predictive of poor outcomes?
3. Should age itself be a criterion for triage from the field directly to a trauma center, regardless of Glasgow Coma Scale (GCS) score, Trauma Score (TS), and so forth? If so, what age should be used?
4. Do trauma centers have better outcomes with geriatric trauma than nontrauma centers?
5. Are there specific injuries, scores (e.g., Injury Severity Score [ISS], TS, GCS score), or PEC/age combinations in geriatric trauma patients that are so unlikely to be survivable that a nonaggressive approach from the outset could be justified?
6. What resuscitation end-points should be used for the geriatric trauma patient?
7. Should all geriatric trauma patients receive invasive hemodynamic monitoring? If so, what specific types of monitoring should be used? If not, which geriatric patients benefit from invasive monitoring?

Unfortunately, after examining the available literature, it is clear thatevidence-based responses to all of the questions raised above are not possible. As the evidentiary tables demonstrate, there are few, if any, prospective, randomized, controlled trials that definitively address any of the above issues. Second, there is a lack of uniformity as to a specific age criterion for geriatric trauma. As shown in the evidentiary tables, geriatric trauma is variously defined in the literature as age greater than or equal to 55, 60, 65, 70, 75, and even 80 years of age. There is even literature support for increased mortality from trauma beginning at age 45! Furthermore, because age is a continuous variable, and not a dichotomous one, adverse outcomes associated with geriatric trauma are likely to increase in a continuous fashion with age as opposed to a stepwise leap as a given patient reaches a specific age. Third, there is no concise definition of a geriatric trauma patient. In some studies, all patients over a given age are included, whereas in others, patients with penetrating injuries, burns, and minor injuries, such as slip-and-falls, are excluded. Some studies include all patients regardless of hemodynamic instability or injury severity, whereas others impose strict entrance criteria or exclude patients who do not survive for a predetermined period of time after admission. Such lack of uniformity regarding inclusion criteria makes it difficult to compare outcomes across different patient populations. Finally, much of the literature concerning geriatric trauma is relatively old, that is, published more than 10 years ago. Given the significant improvements in patient care that have occurred over the past 10 to 20 years, recommendations made on the basis of outcomes achieved more than 10 years ago may not be applicable to today's geriatric trauma patient.

Despite the above-mentioned shortcomings, our committee still felt that it was important to summarize the available literature and make evidence-based recommendations where satisfactory evidence did exist. In light of the seven questions raised above, two broad areas of focus emerged within this guideline: issues of geriatric trauma triage, and issues of geriatric trauma resuscitation. Although there was considerable overlap between these two areas, each issue has been addressed separately within this guideline and, accordingly, two separate subguidelines, each with its own recommendations, evidentiary table, and areas for future research, constitute this practice management guideline for geriatric trauma. It is hoped that the information provided within this guideline will provide evidence-based support for the difficult decisions that are required to achieve optimal outcomes in this difficult but ever-increasing patient group.

Parameters for Resuscitation of the Geriatric Trauma Patient

I. Statement of the Problem

There is no doubt that the elder trauma patient presents trauma surgeons with a complex challenge. The effects of aging on individual organ systems and the presence of comorbid conditions combine to create a milieu that does not allow for errors in resuscitation or delays in diagnosis. It is widely known that geriatric patients have less physiologic reserve than younger patients and that mortality rates are higher than in a younger cohort. There is a growing sentiment that the conduct of resuscitation for the injured elder must be undertaken with an aggressive and thoughtful approach. Outcome data suggest that the elderly benefit from an aggressive approach to resuscitation. It is believed by some that the pulmonary artery catheter should be a routine part of the resuscitation process for the severely injured geriatric patient. In addition, there are certain laboratory assays that have been recommended for use in this clinical scenario. There is confusion, however, regarding end-points for resuscitation and which patients benefit from invasive hemodynamic monitoring.

II. Process

Literature used for these guidelines was obtained by means of a search of the MEDLINE database from the National Library of Medicine. Citations in the English language during the period of 1966 through 1999 using the words elderly, geriatric, trauma, shock, and resuscitation were identified. Citations concerned primarily with multisystem trauma or single-organ injury in a multisystem context were used. Additional nontrauma references were used to relate epidemiologic or physiologic factors concerning the geriatric patient to the context of potential injury. This search identified 4,783 references. For use in the evidentiary table (Table 2), these were then sorted to identify articles associated with geriatric trauma patients exclusively. The bibliographies of each article were searched for additional references not identified by the original MEDLINE query. Letters to the editor, case reports, review articles, and series examining nontrauma patients were excluded for use in the evidentiary table (Table 2). The references were classified by methods used by the Canadian and United States Preventative Task Force. Classification of references was graded on the basis of the strength of the scientific evidence. For purposes of practice management guidelines for trauma, data were classified as follows:

Class I: Prospective randomized controlled trials (PRCTs)-the gold standard of clinical trials. Some may be poorly designed, have inadequate numbers, or suffer from other methodologic inadequacies, and thus may not be clinically significant (one reference).

Class II: Clinical studies in which the data were collected prospectively, and retrospective analyses that were based on clearly reliable data. These types of studies include observational studies, cohort studies, prevalence studies, and case control studies (one reference).

Class III: Most studies based on retrospectively collected data. Evidence used in this class includes clinical series, databases or registries, case reviews, case reports, and expert opinion (seven references).

III. Recommendations

A. Level I:

There are insufficient data to support a Level I recommendation for the method and end-points of resuscitation in the elderly patient as a standard of care.

B. Level II:

1. Any geriatric patient with physiologic compromise, significant injury (Abbreviated Injury Scale [AIS] score > 3), and high-risk mechanism of injury, uncertain cardiovascular status, or chronic cardiovascular or renal disease should undergo invasive hemodynamic monitoring using a pulmonary artery catheter.

2. There are insufficient data to support a Level II recommendation for the method and end-points of resuscitation in the elderly patient as a standard of care.

C. Level III:

1. Attempts should be made to optimize to a cardiac index ≥ 4 L/min/m^[2] and/or an oxygen consumption index of 170 mL/min/m^[2].

2. Base deficit measurements may provide useful information in determining status of resuscitation and risk of mortality.

IV. Scientific Foundation

It is widely known that the citizenry of the United States is continuing to age.^[49-51] The elderly population (65 years and older) increased 11-fold from 1900 to 1994, whereas the segment under the age of 65 increased only 3-fold during the same period.^[50] Data from the U.S. government shows that the life expectancy of the U.S. population reached 76.5 years, the highest at any time in U.S. history.^[49] There will be a dramatic increase in the elderly population because of the aging of the baby-boom generation (75 million babies born between 1946 and 1964).^[50] Although projection assumptions vary, using the Census Bureau's Middle Series projections (moderate fertility, mortality, and immigration assumptions), the elderly will make up 12.8% of the population by 2000 and 20.4% by 2050.^[50]

Trauma ranks as the fifth leading cause of death when considering all races, both sexes, and all ages.^[49] For patients 65 years and over, trauma ranks seventh as a cause of death, although the rate per 100,000 is 92.1 compared with 35.7 for all age groups. Unlike younger age groups, there is relatively little variation in death rates between black and white races. These data indicate that in the future there will be an unprecedented number of elderly persons at risk for injury.

Advancing age is associated with a gradual decline in organ function. Problems attributable solely to senescence and diseases not associated with age may be difficult to distinguish from one another, but it is important to account for all disorders concomitant with the injury. The walls of the heart become less compliant and cardiac index decreases 1% per year with age and systemic vascular resistance increases 1% per year.^[52] Maximum heart rate is also reduced with age. In addition, the heart is less able to respond to the stress of injury, as there is an age-related decrease in the effectiveness of adrenergic stimulation.^[53] The prevalence of hypertension also increases as a function of age. In the United States, 59.2% of white men aged 65 to 74 are hypertensive, and this increases dramatically to 82.9% in elderly black women.^[54] The end result of these age-related changes is a decreased ability to respond to the stress of injury or critical illness.

There are numerous changes in respiratory function with increasing age. The chest wall becomes less compliant and the elasticity of the lung decreases.^[52] The loss of compliance results in a greater dependence on diaphragmatic breathing.

Renal mass is rapidly lost after the age of 50, and a corresponding fall in glomerular filtration rate occurs beyond the age of 60 because of the loss of nephrons.^[52] Measurement of creatinine clearance becomes more important in the geriatric patient, because serum creatinine may be lowered as a result of decreased muscle mass, giving a false sense of security with respect to renal function. Age-related vascular changes result in a decreased percentage of blood flow to the older kidney.^[52]

Deteriorating endocrine function is also seen with advancing age. The production and turnover of thyroid hormone species is significantly reduced.^[55] Tissue responsiveness to thyroid hormone is lessened, resulting in striking similarities between clinical hypothyroidism and the changes commonly seen in the elderly as a result of senescence.^[55] Normal adrenal function is critical to respond to the stress of injury and critical illness. Basal, circadian, and stimulated cortisol secretion remains intact with aging.^[56] There is an age-related decrease in the catabolism of cortisol, although this is compensated for by a decrease in the rate of catabolism.

The question of whether or not preexisting disease contributes to poor outcome has not yet been conclusively answered, and is more fully discussed in the preceding section. The prevalence of comorbid conditions in trauma patients is between 8.8% and 19.3%.^[57] In injured patients older than 65 years, however, the incidence climbs to 30%.^[58] Milzman et al. found that by 75 years, 69% of patients had one or more preexisting conditions.^[33] Smith et al. found at least one comorbidity in 61.6% of patients in their series.^[37] In a study of 102 patients from Switzerland admitted with femur fractures, 16% presented with a single comorbid condition, 45% presented with two comorbid conditions, 28% presented with three conditions, and 11% presented with four.^[59] Battistella et al. found an average of two preexisting medical problems in injured patients aged 75 years and older.^[27] After controlling for age, Sacco et al. found that hepatic, cardiovascular, respiratory, and renal disease and diabetes adversely affected survival.^[60] Milzman et al. and MacKenzie et al. noted higher mortalities and longer lengths of stay in patients with increased numbers of preexisting conditions.^[33][61]

Criteria for hemodynamic monitoring are not clear in this population. The gravity of this situation is underscored because it has been found that the elderly patient is more likely to present in shock than younger patients with similar trauma and Injury Severity Scores.^[62] In geriatric patients undergoing elective surgery, occult physiologic compromise has been shown to contribute to poor outcome. DelGuerico and Cohn found significant physiologic compromise in geriatric patients who had been cleared for elective surgery.^[63] Among those who could not be optimized before surgery, all died postoperatively. Similar work has also been performed in trauma patients.

Scalea et al. found significant measurable hemodynamic compromise in elderly patients who were clinically stable after initial evaluation after blunt multiple trauma.^[64] On the basis of institutional experience, criteria were developed to select patients for invasive hemodynamic monitoring. These criteria included pedestrian-motor vehicle mechanism, initial blood pressure < 150 mm Hg, acidosis, multiple fractures, and head injury. Patients were moved to the intensive care unit as quickly as possible. Pulmonary artery catheters and arterial lines were inserted in all patients. Volume infusion and inotropes were used to augment hemodynamic parameters. Attempts were made to optimize patients to a cardiac index ≥ 4 L/min/m^[2] or an oxygen consumption index of 170 mL/min/m^[2]. Thirteen of 30 patients were found to be in cardiogenic shock and 54% of these died. There were statistically significant differences between optimized cardiac output and systemic vascular resistance in survivors compared with nonsurvivors. The vital message from this important work is that a geriatric patient with multiple injuries may appear stable yet have a profound perfusion deficit from a dangerously low cardiac output. The early use of invasive hemodynamic monitoring will identify this deficit and afford the opportunity to help improve survival.

The only randomized data concerning resuscitation in geriatric patients was conducted by Schultz et al.^[65] These authors studied the role of physiologic monitoring in patients with fractures of the hip. Seventy patients were randomly divided into a monitored group and a control group. A central venous line was placed into the control group and a pulmonary artery catheter into the monitored group. The mean age for the nonmonitored group was 67 years (range, 40-89 years) and that for the monitored group was 78 years (range, 40-95 years). On the basis of the data obtained, physiologic abnormalities were appropriately corrected. Postoperative morbidity was similar between the two groups. The postoperative mortality in the monitored group was 2.9% and the mortality in the nonmonitored group was 29%. The primary weakness in this study is that no clear parameters are provided to guide resuscitation. This study evaluated patients with hip fractures and not the multisystem elderly trauma patient.

Tornetta et al. retrospectively reviewed 326 patients 60 years of age or greater at four hospitals.^[25] Using univariate analysis, patients who died displayed significantly greater transfusion requirement (10.9 vs. 2.9 U) and fluid infusion (12.4 vs. 4.9 L). Both transfusion and fluid requirements were found to be predictive of mortality. The authors concluded that the risks of invasive monitoring are justified in patients with an ISS > 18, but for patients with an ISS < 18, indications need to be clarified.

The importance of shock and fluid replacement in the elder trauma patient was addressed by Oreskovich et al.^[22] One hundred consecutive elderly patients (mean age, 74 years) were followed for a minimum of 1 year. A profile of the nonsurvivor was constructed: (1) prehospital intubation (93% mortality), (2) shock (100%), (3) intubated greater than 5 days (100%), and (4) gram-negative pulmonary sepsis (80%). All nonsurvivors were in shock (systolic blood pressure < 80 mm Hg) for at least 15 minutes between injury and admission. Only 6% of survivors were found to be in shock. During this study, the protocol for prehospital care in the hypotensive patient called for 2,200 mL of lactated Ringer's solution before arrival at hospital.

Perdue et al. retrospectively studied 4,691 patients aged 16 to 64 years and compared these with 448 patients aged 65 years or greater.^[17] Elderly mortality was 14% compared with 6% in the younger cohort, and the difference was statistically significant (p < 0.001). After controlling for Injury Severity Score, Revised Trauma Score, preexisting disease, and complications, the elderly were 4.6 times as likely to die compared with the young. The author's practice is to admit elderly patients to the ICU if they have significant injury (AIS score > 3), shock, or significant chronic cardiovascular or renal disease. Pulmonary artery catheters were not placed unless volume or cardiac status was uncertain.

Knudson et al. retrospectively analyzed physiologic status in 852 blunt trauma patients aged 65 years or older.^[18] Mortality increased with a decreasing TS and was 100% with a TS < 7. Each individual component of the TS was found to be predictive of mortality when analyzed independently. A systolic blood pressure < 90 mm Hg was associated with an 82% mortality rate. Multiple logistic regression analysis was used to construct a formula to help predict which patients would benefit from aggressive resuscitation.

Physiologic status was also addressed by Pellicane et al.^[16] The authors reviewed 374 consecutive trauma patients over the age of 65 years. Trauma score was significantly (p < 0.001) higher in patients who survived. Mortality was significantly (p < 0.05) increased in patients with a TS < 12 (65%) and a TS of 12 to 14 (25%) when compared with patients with a TS of 15 to 16 (5%). The authors concluded that geriatric patients with a TS < 15 are at high risk for complications and should be admitted to the ICU and treated aggressively.

Horst et al. retrospectively studied 39 trauma patients over the age of 60 years.^[19] Patients were admitted to the intensive care unit and monitored with arterial and pulmonary artery catheters. Fifteen (38%) patients presented with shock (systolic blood pressure < 80 mm Hg). Although survivors tended to have higher mean arterial blood pressure, cardiac index, left ventricular stroke work, and oxygen delivery, the differences compared with nonsurvivors were not statistically significant.

The importance of shock was further underscored by van Aalst et al.^[5] The authors retrospectively analyzed 98 geriatric (≥ 65 years) blunt trauma patients with ISS ≥ 16. Of 48 surviving patients, only 1 presented in shock. Of the 50 nonsurvivors, 15 presented in shock. The presence of shock (systolic blood pressure < 90 mm Hg) at admission was the most significant factor associated with a poor outcome. Sepsis was also identified as a factor contributing to poor outcome.

The state of resuscitation as evaluated by base deficit was evaluated by Davis and Kaups.^[7] The authors studied the utility of base deficit in 274 patients aged 55 years and older. Arterial blood gases were obtained within 1 hour of admission. There was a statistically significant increase in mortality with increasing base deficit. Compared with a younger cohort, mortality in the elderly was significantly increased for a given base deficit despite similar Injury Severity Scores. The positive predictive value of base deficit for significant injury was similar between young and old, but the negative predictive value was significantly better in younger patients. The authors concluded that a base deficit < -6 is particularly ominous in elderly trauma patients.

The above data emphasize the importance of close hemodynamic monitoring and careful trending of vital signs rather than relying on a single set of normal vital signs.^[66] Because the elderly patient is often not able to generate an augmented cardiac output in response to hemorrhage, early invasive hemodynamic monitoring and judicious use of vasoactive drugs (after appropriate fluid resuscitation) as recommended by Scalea et al. should be recommended for any geriatric patient with significant injuries.

V. Summary

The elderly (65 years and older) are the fastest growing segment of the U.S. population. Although trauma is only the seventh leading cause of death in the elderly, the death rate (per 100,000) is significantly higher when compared with a younger cohort. U.S. Bureau of Census data indicate that in the future there will be an unprecedented number of elderly persons at risk for injury.

It is widely known that the elderly display a high incidence of premorbid conditions. However, the question of whether or not preexisting disease contributes to poor outcome after injury has yet to be conclusively answered. Several studies have indicated that shock, respiratory failure, decreasing TS, increasing ISS, increasing base deficit, and infectious complications portend a poor outcome in the elderly.

Data indicate that the geriatric patient with multiple injuries may appear stable yet have a profound perfusion deficit secondary to low cardiac output. The early use of invasive hemodynamic monitoring may afford the opportunity to help improve survival.

Although the injured elder is more likely to die than the younger patient, an aggressive treatment program will allow many geriatric patients to regain their preinjury independence. Attention to detail, although important for all trauma patients, must be heightened in the injured elder, as the opportunity for good outcomes may be fleeting.

VI. Future Investigations

The paucity of literature evaluating the conduct and end-points of resuscitation of the geriatric trauma patient requires that further clinical work be conducted. Randomized trials in severely injured geriatric patients must be performed to determine which patients would benefit from invasive monitoring and the end-points that should be used for completing the resuscitation. Trials such as this, however, have ethical, medicolegal, and methodologic implications that may prevent their inception.

There are many parameters that have been shown to correlate with poor outcome in this population. We have no control over some of these, such as patient age. Some can be controlled with prevention techniques, as in the case of the pedestrian-motor vehicle crash, which has been shown to be associated with mortality. As clinical practitioners, we should focus our efforts on those areas where we would be able to exert an impact. The shock state, acidosis, and sepsis have been shown to directly correlate with mortality. Aggressive identification, correction, and monitoring of these pathophysiologic states may be able to improve outcome. Laboratory assays, such as base deficit, may have promise for measuring the adequacy and completeness of resuscitation. Certain drugs, such as beta-blockers, have been shown to improve outcome in elderly general surgery patients, but have not yet been studied in trauma patients.

VII. References

1. American College of Surgeons, Committee on Trauma. Resources for Optimal Care of the Injured Patient: 1999. Chicago, IL: American College of Surgeons; 1998: 14.
2. Champion HR, Copes WS, Buyer D, Flanagan ME, Bain L, Sacco WJ. Major trauma in geriatric patients. Am J Public Health. 1989; 79: 1278-1282.
3. McCoy GF, Johnston RA, Duthie RB. Injury to the elderly in road traffic accidents. J Trauma. 1989; 29: 494-497.
4. Morris JAJ, MacKenzie EJ, Damiano AM, Bass SM. Mortality in trauma patients: the interaction between host factors and severity. J Trauma. 1990; 30: 1476-1482.
5. van Aalst JA, Morris JAJ, Yates HK, Miller RS, Bass SM. Severely injured geriatric patients return to independent living: a study of factors influencing function and independence. J Trauma. 1991; 31: 1096-1101.
6. DeMaria EJ, Kenney PR, Merriam MA, Casanova LA, Gann DS. Survival after trauma in geriatric patients. Ann Surg. 1987; 206: 738-743.
7. Davis JW, Kaups KL. Base deficit in the elderly: a marker of severe injury and death. J Trauma. 1998; 45: 873-877.
8. Gubler KD, Davis R, Koepsell T, Soderberg R, Maier RV, Rivara FP. Long-term survival of elderly trauma patients. Arch Surg. 1997; 132: 1010-1014.
9. Osler T, Hales K, Baack B, et al. Trauma in the elderly. Am J Surg. 1988; 156: 537-543.
10. Finelli FC, Jonsson J, Champion HR, Morelli S, Fouty WJ. A case control study for major trauma in geriatric patients. J Trauma. 1989; 29: 541-548.
11. Smith JSJ, Martin LF, Young WW, Macioce DP. Do trauma centers improve outcome over non-trauma centers: the evaluation of regional trauma care using discharge abstract data and patient management categories. J Trauma. 1990; 30: 1533-1538.
12. Ma MH, MacKenzie EJ, Alcorta R, Kelen GD. Compliance with prehospital triage protocols for major trauma patients. J Trauma. 1999; 46: 168-175.
13. Phillips S, Rond PC, Kelly SM, Swartz PD. The failure of triage criteria to identify geriatric patients with trauma: results from the Florida Trauma Triage Study. J Trauma. 1996; 40: 278-283.
14. Zimmer-Gembeck MJ, Southard PA, Hedges JR, et al. Triage in an established trauma system. J Trauma. 1995; 39: 922-928.
15. Vollmer DG. Age and outcome following traumatic coma: why do older patients fare worse? J Neurosurg. 1991; 75: S37-S49.
16. Pellicane JV, Byrne K, DeMaria EJ. Preventable complications and death from multiple organ failure among geriatric trauma victims. J Trauma. 1992; 33: 440-444.
17. Perdue PW, Watts DD, Kaufmann CR, Trask AL. Differences in mortality between elderly and younger adult trauma patients: geriatric status increases risk of delayed death. J Trauma. 1998; 45: 805-810.
18. Knudson MM, Lieberman J, Morris JAJ, Cushing BM, Stubbs HA. Mortality factors in geriatric blunt trauma patients. Arch Surg. 1994; 129: 448-453.
19. Horst HM, Obeid FN, Sorensen VJ, Bivins BA. Factors influencing survival of elderly trauma patients. Crit Care Med. 1986; 14: 681-684.
20. Shabot MM, Johnson CL. Outcome from critical care in the oldest old trauma patients. J Trauma. 1995; 39: 254-259.
21. van der Sluis CK, Timmer HW, Eisma WH, ten Duis HJ. Outcome in elderly injured patients: injury severity versus host factors. Injury. 1997; 28: 588-592.
22. Oreskovich MR, Howard JD, Copass MK, Carrico CJ. Geriatric trauma: injury patterns and outcome. J Trauma. 1984; 24: 565-572.
23. Broos PL, Stappaerts KH, Rommens PM, Louette LK, Gruwez JA. Polytrauma in patients of 65 and over: injury patterns and outcome. Int Surg. 1988; 73: 119-122.
24. Broos PL, D'Hoore A, Vanderschot P, Rommens PM, Stappaerts KH. Multiple trauma in elderly patients: factors influencing outcome-importance of aggressive care. Injury. 1993; 24: 365-368.
25. Tornetta P, Mostafavi H, Riina J, et al. Morbidity and mortality in elderly trauma patients. J Trauma. 1999; 46: 702-706.
26. Johnson CL, Margulies DR, Kearney TJ, Hiatt JR, Shabot MM. Trauma in the elderly: an analysis of outcomes based on age. Am Surg. 1994; 60: 899-902.
27. Battistella FD, Din AM, Perez L. Trauma patients 75 years and older: long-term follow-up results justify aggressive management. J Trauma. 1998; 44: 618-623.
28. Carrillo EH, Richardson JD, Malias MA, Cryer HM, Miller FB. Long term outcome of blunt trauma care in the elderly. Surg Gynecol Obstet. 1993; 176: 559-564.
29. Zietlow SP, Capizzi PJ, Bannon MP, Farnell MB. Multisystem geriatric trauma. J Trauma. 1994; 37: 985-988.
30. DeMaria EJ, Kenney PR, Merriam MA, Casanova LA, Gann DS. Aggressive trauma care benefits the elderly. J Trauma. 1987; 27: 1200-1206.
31. Day RJ, Vinen J, Hewitt-Falls E. Major trauma outcomes in the elderly. Med J Aust. 1994; 160: 675-678.
32. Morris JAJ, MacKenzie EJ, Edelstein SL. The effect of preexisting conditions on mortality in trauma patients. JAMA. 1990; 263: 1942-1946.
33. Milzman DP, Boulanger BR, Rodriguez A, Soderstrom CA, Mitchell KA, Magnant CM. Pre-existing disease in trauma patients: a predictor of fate independent of age and injury severity score. J Trauma. 1992; 32: 236-243.
34. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis. 1987; 40: 373-383.
35. van der Sluis CK, Klasen HJ, Eisma WH, ten Duis HJ. Major trauma in young and old: what is the difference? J Trauma. 1996; 40: 78-82.
36. Shapiro MB, Dechert RE, Colwell C, Bartlett RH, Rodriguez JL. Geriatric trauma: aggressive intensive care unit management is justified. Am Surg. 1994; 60: 695-698.
37. Smith DP, Enderson BL, Maull KI. Trauma in the elderly: determinants of outcome. South Med J. 1990; 83: 171-177.
38. Howard MA, Gross AS, Dacey RGJ, Winn HR. Acute subdural hematomas: an age-dependent clinical entity. J Neurosurg. 1989; 71: 858-863.
39. Rakier A, Guilburd JN, Soustiel JF, Zaaroor M, Feinsod M. Head injuries in the elderly. Brain Inj. 1995; 9: 187-193.
40. Jamjoom A, Nelson R, Stranjalis G, et al. Outcome following surgical evacuation of traumatic intracranial haematomas in the elderly. Br J Neurosurg. 1992; 6: 27-32.
41. Kotwica Z, Jakubowski JK. Acute head injuries in the elderly: an analysis of 136 consecutive patients. Acta Neurochir (Wien). 1992; 118: 98-102.
42. Pennings JL, Bachulis BL, Simons CT, Slazinski T. Survival after severe brain injury in the aged. Arch Surg. 1993; 128: 787-793.
43. Rozzelle CJ, Wofford JL, Branch CL. Predictors of hospital mortality in older patients with subdural hematoma. J Am Geriatr Soc. 1995; 43: 240-244.
44. Kilaru S, Garb J, Emhoff T, et al. Long-term functional status and mortality of elderly patients with severe closed head injuries. J Trauma. 1996; 41: 957-963.
45. Ross AM, Pitts LH, Kobayashi S. Prognosticators of outcome after major head injury in the elderly. J Neurosci Nurs. 1992; 24: 88-93.
46. Reuter F. Traumatic intracranial hemorrhages in elderly people. Adv Neurosurg. 1989; 17: 43-48.
47. Cagetti B, Cossu M, Pau A, Rivano C, Viale G. The outcome from acute subdural and epidural intracranial haematomas in very elderly patients. Br J Neurosurg. 1992; 6: 227-231.
48. Amacher AL, Bybee DE. Toleration of head injury by the elderly. Neurosurgery. 1987; 20: 954-958.
49. Hoyert DL, Kochanek KD, Murphy SL. Deaths: final data for 1997. National Vital Statistics Reports from the Centers for Disease Control and Prevention. Available at:http://www.cdc.gov/nchswww/data/nvs47_19.pdf. Accessed August 13, 1999.
50. U.S. Bureau of the Census. Current Population Reports, Special Studies, P23-190, 65+ in the United States. Available at: http://www.census.gov/prod/1/pop/p23-190/p23-190.html. Accessed July 31, 1999.
51. Markus GR. The graying of America: major Social Security and Medicare battles are just beginning. Bull Am Coll Surg. 1997; 82: 25-30.
52. Fairman R, Rombeau JL. Physiologic problems in the elderly surgical patient. In: Miller TA, Rowlands BJ, eds. Physiologic Basis of Modern Surgical Care. St. Louis: CV Mosby; 1988: 1108-1117.
53. Lakatta EG. Age-related alterations in the cardiovascular response to adrenergic mediated stress. Fed Proc. 1980; 39: 3173-3177.
54. Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure. The 1992 Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC-V). Arch Intern Med. 1993; 153: 154-183.
55. Mooradian AD. Normal age-related changes in thyroid hormone economy. Clin Geriatr Med. 1995; 11: 159-169.
56. Belchetz PE. Pituitary and adrenal disorders in old age. In: Brocklehurst JC, Tallis RC, Fillit H, eds. Textbook of Geriatric Medicine and Gerontology. 4th ed. Edinburgh: Churchill Livingstone; 1992: 694-700.
57. McMahon DJ, Schwab CW, Kauder D. Comorbidity and the elderly trauma patient. World J Surg. 1996; 20: 1113-1120.
58. Schwab CW, Kauder DR. Geriatric trauma. In: Moore EE, Ducker TB, Edlich FR, et al., eds. Early Care of the Injured Patient. Toronto: BD Decker; 1990: 328-334.
59. Sartoretti C, Sartoretti-Schefer S, Ruckert R, et al. Comorbid conditions in old patients with femur fractures. J Trauma. 1997; 43: 570-577.
60. Sacco WJ, Copes WS, Bain LW, et al. Effect of preinjury illness on trauma patient survival outcome. J Trauma. 1993; 35: 538-543.
61. MacKenzie EJ, Morris J, Edelstein S. Effect of pre-existing disease on length of hospital stay in trauma patients. J Trauma. 1989; 29: 757-765.
62. Clancy TV, Ramshaw DG, Maxwell JG, et al. Management outcomes in splenic injury. Ann Surg. 1997; 226: 17-24.
63. DelGuercio LR, Cohn JD. Monitoring operative risk in the elderly. JAMA. 1980; 243: 1350-1313.
64. Scalea TM, Simon HM, Duncan AO, et al. Geriatric blunt multiple trauma: improved survival with invasive monitoring. J Trauma. 1990; 30: 129-136.
65. Schultz RJ, Whitfield GF, LaMura JJ, et al. The role of physiologic monitoring in patients with fractures of the hip. J Trauma. 1985; 25: 309-316.
66. Demarest GB, Osler TM, Clevenger FW. Injuries in the elderly: evaluation and initial response. Geriatrics. 1990; 45: 36-42.

Table

Evidentiary Table: Resuscitation Goals in Geriatric Trauma