Journal of Gerontological Nursing

TRAUMA IN THE ELDERLY

Judith K Bobb, MSN, RN

Abstract

The elderly often die as a result of injuries of relatively low severity.

Abstract

The elderly often die as a result of injuries of relatively low severity.

Each year, more elderly enter the healthcare system as a result of injury. Falls, road traffic incidents, and thermal injury account for most hospital admissions of persons over 60 years of age.1·2 The elderly often die as a result of injuries of relatively low severity, injuries that would have been survived by younger persons, despite a generally lower incidence of injury in the elderly members of the population.

Falls, the most frequent cause of injury in the aged, have been extensively documented in the literature with respect to injury severity and outcomes.38 Less well understood are the consequences of road traffic trauma, including pedestrian injuries. Although the elderly are represented in the trauma research literature, most investigators report their data in the aggregate, preventing an adequate understanding of this subpopulation.9·10 In addition, elderly often present with unique clinical problems secondary to preexisting injury and disease. Many clinicians believe this contributes to higher mortality in the aged, but this assumption is not well supported by research. In fact, little is known of the response of the elderly to injury or the contribution of preinjury health status to recovery or to death.

Review of Literature

Motor vehicle fatalities for those over 65 years of age account for 1 1 . 3% of the mortality from motor vehicle accidents for all ages and 25% of the deaths from all injuries in older individuals.3 Motor vehicle accident victims include drivers, occupants, and pedestrians struck by vehicles. The number of deaths from motor vehicle injury is lower for people aged 65 and older (5,944 deaths in 1981) than for those aged 15 to 24 years (26,622 deaths in 198I).11 The elderly have a high accident rate despite the fact that they tend to drive fewer miles annually.3 The National Safety Council" reported an accident rate (number of accidents per million driving miles) of 16.3 for drivers over age 70. This is exceeded only by the accident rate of 25.1 for drivers 16 to 20 years of age.

Other than incidence rates and mortality statistics, little information is available from the literature concerning the effects of motor vehicle injury upon the elderly.

Oreskovich et al2 studied 100 patients aged 70 years and older who were hospitalized as a result of severe trauma. They examined age, mechanism of injury, shock, body region injured, injury severity score,12 level of function, and predictors of survival. Motor vehicle injuries represented 17% of the sample, but were not analyzed independently from the other mechanisms of injury.

When factors affecting survival were examined, they found no difference between survivors and nonsurvivors in age, sex, injury severity scores (ISSs),12 pre-existing disease, or preinjury level of function. There was a significant difference between survivors and nonsurvivors for body region involved: nonsurvivors had significantly higher involvement of the central nervous system, and all nonsurvivors were admitted in shock.

Allen and Schwab13 studied 48 patients aged 60 years and older who were hospitalized with blunt trauma to the chest. The patients in this study experienced an average injury severity score of 18. They noted that close to 100% of the subjects who required intubation were injured as a result of motor vehicle accidents and had ISSs approximately twice those of persons injured by other mechanisms.

The Study

To expand the existing limited data base, a retrospective study was conducted that described the impact of motor vehicle trauma in the elderly.14 The Shock Trauma Center of the Maryland Institute for Emergency Medical Services Systems, a level I trauma center serving the state of Maryland, was selected for the study. Over a two-year period (January 1983 to December 1985), 122 patients aged 55 years and older were admitted directly from the scene of injury. (Age 55 years was selected in the hope that age differences in severity of injury and outcome would become evident.) The medical records were examined for the type and severity of injury, initial clinical findings, and health status prior to injury.

Six research questions were developed for the study. They examined differences in severity of injury among drivers, occupants, and pedestrians and the relationship between length of hospitalization and age, severity of injury, and health status prior to injury. The value of age, severity of injury, and health status prior to injury in the prediction of survival were also examined.

Instruments

Two measures of severity of injury were used. The ISS12 was used to measure anatomical injury. AU injuries noted in the medical record were given a weighted score and grouped according to the body region involved. The ISS was calculated by squaring the three highest scores and summing the results. The highest possible ISS is 75, representing lethal injury. Scores of 50 and above were considered severe injury; those from 21 to 49 were moderate; and scores of 20 or less were considered mild in severity.

Physiological severity of injury was measured using a modified form of the acute physiology score (APS).15 This tool consists of 34 clinical and laboratory measurements (eg, mean arterial pressure, respiratory rate, serum potassium level) that describe the physiological status of the patient. Some modifications of the tool were necessary because of absence of data in the medical record which resulted in a highest possible score of 92.

Health status prior to admission was measured from the history as documented in the medical record. A scale was constructed to weigh the severity of chronic diseases in four body systems: cardiovascular, respiratory, neurological, and endocrine. These systems were selected because impairment in one or more was felt to have high potential for impairment of survival following injury, as suggested by documentation of the leading causes of death in the elderly. 16 The scale and the weighting system were verified by a panel of nurse experts in gerontology and trauma. The highest possible score was 37, representing a high incidence of chronic disease existing prior to injury.

Sample

There were 56 males and 66 females entered into the study. The age ranged from 55 to 101 years, with a mean of 67.9 years. The sample included 60 drivers, 16 occupants, 45 pedestrians, and one unknown. Length of hospitalization ranged from less than one to 234 days, with a mean of 19.4 days for survivors and 9. 1 days for nonsurvivors. However, 50% of the subjects were hospitalized for eight days or less. The overall mortality was 18.9% (23 persons).

ISSs ranged from 1 to 75, with a mean of 14.7. Fifty percent of the subjects had an ISS of 12 or less. APSs ranged from 0 to 38, with a mean of 8.2. Health status scores ranged from 0 to 22, with a mean of 5.4. One third of the subjects had no chronic diseases noted in the history.

Results

The sample was examined for differences in severity of injury among drivers, occupants, and pedestrians. No differences were found for ISSs or APSs. No relationship was found between length of hospitalization and age.

The third hypothesis looked at the relationship between length of hospitalization and the ISS, the subscales of the ISS, and the APS. There were differences between survivors and nonsurvivors. For survivors the length of hospitalization was greater when ISS and APS scores were higher and when serious injury to the face was present. For nonsurvivors, severe injury to the head and neck was associated with shorter hospitalization; hospitalization lengthened with increased severity of injury to the face.

The fourth hypothesis tested the relationship between the length of hospitalization and health status prior to injury. No significant relationship was found for survivors, but a low positive relationship was found in nonsurvivors. Analysis of the fifth hypothesis found no relationship between age, health status, and measures of severity of injury in the nonsurvivors.

The last hypothesis tested the ability of the combination of age, severity of injury, and health status prior to injury to predict survival. The combination of variables accounted for nearly 50% of the variance in survival. The APS alone accounted for 30% of the variance, followed by the ISS, age, and health status.

Additional Findings

During data analysis, the opportunity arose to determine if there were agerelated differences in the sample that could contribute to a chronological definition of aging. (Measures of severity of injury and mortality were also examined further.)

The overall mortality in this sample was 18.9%. The mortality rate for those younger than 65 years was under 7%. Between 66 and 70 years of age, the mortality rate was 11.1% and rose steadily thereafter, reaching 60% for those subjects between 81 and 101 years of age. The difference was statistically significant.

ISSs generally were higher with advancing age. The average ISS ranged from 13.4 to 26.1. The highest score occurred in the 76- to 81 -year age group, but this was the group that included one patient who had sustained an ISS of 75. Even if this individual is removed from calculation of the average, the ISS is still highest in this age group, with an average of 22.

APSs also tended to be higher for the older age groups. The average APS for the entire sample was 8.20, while that for individuals of age 76 and over was 12.06. Within the APS subscales, the cardiovascular, respiratory, and neurological subscales showed a strong positive correlation with the total score.

The results of this examination for age-related differences suggest that age 76 years and over may be more appropriate than age 65 when chronological age is used to reflect the limitations imposed by advancing age. This finding reflects reported life expectancies for this age cohort.17 Despite the convenience of chronological age as a definition of elderly, it has not been substantiated as an adequate criterion for therapeutic interventions.

Oreskovich et al2 reported that 100% of nonsurvivors and only 6% of survivors of severe trauma were in shock. Shock was defined as a blood pressure less than 80 mmHg for 15 minutes before admission. A comparison was made with the subjects in the present study whose initial mean arterial blood pressure was 70 mmHg or less. Thirty patients presented with blood pressures less than 70 mmHg. Eleven died, resulting in a mortality of 37%.

The difference between these results and those of Oreskovich et al may be due to the difference in age between the two samples or to the fact that most of the subjects in the Oreskovich study were injured as a result of a fall. It is possible that differences in chronic health status exist between those elderly who fall and those who are involved in motor vehicle accidents.

Oreskovich et al also reported a 20% incidence of serious central nervous system injury in nonsurvivors, which was significantly related to mortality, compared with an incidence of 11% in survivors. In the present study, 16 of the 23 nonsurvivors experienced head and neck injuries, eight of which were moderate to severe (34.7%). The most frequent type of injury was intracranial bleeding (nine subjects). The frequency of moderate to severe head and neck injury in survivors was 18.9% (11 of 58). These findings indicate probable differences between the samples from the two studies.

Oreskovich et al2 reported that 88% of the subjects hospitalized for severe injuries did not return to their previous level of independence. Seventy-two percent of this population required full nursing assistance one year after injury. On the other hand, Allen and Schwab13 reported that 90% of their subjects with blunt chest trauma were discharged home and returned to an independent life. Although the subjects in the present study were not followed beyond hospitalization, discharge outcome was known for 73 survivors. Sixty-six percent were discharged home; 23% to a rehabilitation facility; 4% to another acute care facility; and only 7% to a chronic care agency. Once again, the differences between the two studies suggest major differences in the patient populations.

Discussion

Perhaps the most significant finding from this study is that health status prior to injury had little relationship to length of hospitalization or to survival. Although the literature implies that the presence of chronic diseases, particularly of the cardiovascular system, will impair the elderly person's ability to survive a major physiological insult such as trauma, this was not substantiated in this study. Nor was chronic health found to contribute to decreased survival in two other recent studies of geriatric trauma.2·13 A possible explanation for this finding is the manner in which chronic health is assessed.

In each of the three studies cited, health status was determined from the patient's history. The measure used for data analysis became a listing of medical diagnoses. Although it seems logical to conclude that a greater incidence of chronic disease is associated with poorer outcome, this was not upheld in the studies. A plausible explanation is that the medical diagnoses are inadequate measures of impairment in functional capacity for the individual. This explanation is supported by the finding that the APS was the best predictor of survival in the present sample.

Of note is the number of subjects in this sample who had essentially insignificant injuries (30% had lacerations and/or abrasions alone) and whose histories were negative for chronic disease (46%). This finding raises a question as to the criteria used to triage elderly patients to trauma centers. It appears that age played a significant role in the triage decision, yet age alone has not proved to be a highly significant determinant of survival.

Implications

The motor vehicle is one of the most lethal weapons in modern society. Despite the efforts of highway engineers and automotive safety designers, the annual loss of life and limb associated with road traffic accidents is staggering. More than 140,000 Americans die from injuries each year; me dollar cost per year for treatment and lost wages is estimated at $75 to $100 billion. 18 In addition, for each person who dies, approximately 15 are injured.19

The individual who is not killed outright in an automobile accident may still die if treatment is delayed or ineffective. Rapid evacuation from the scene and definitive treatment at a trauma center can result in a reduction of trauma mortality to as low as 15%. ^

Nurses working with trauma patients during initial treatment have learned to anticipate the types of injuries associated with road traffic accidents and the way that individuals usually respond to their injuries. Initial treatment plans and protocols are based upon recognition of the mechanism of injury, the physiological response to injury, and the effectiveness of normal compensatory mechanisms. Anticipating the response to injury allows initial emergency care to proceed before the full nature of the injury is established. In most respects, the process is similar to that necessary for cardiopulmonary resuscitation.

The initial plan of care is based on knowledge gained from the typical trauma victim who is under 40 years of age. It is conceivable that what works for the young may not work for the old. Unfortunately, too little is known about the elderly's response to injury.

Preliminary studies of the elderly14 suggest that the "healthy" elderly should be treated in the same manner as the young. However, the available data are inadequate to determine how the "healthy" are to be identified or what changes should be instituted if the individual is not "healthy. " The nurse must also remember that the elderly patient with relatively minor injuries is still at risk of dying.

Comparison of the results of the present study with those of Oreskovich and Allen and Schwab also suggests that there are differences between the elderly person who is injured as a result of a fall and one who is injured in a motor vehicle accident. Falls are frequently associated with deteriorating health21 prior to the time of accident. Although this was not determined in the studies of motor vehicle injury, the absence of significant chronic disease in 30% of the subjects raises the question of functional differences between the two groups. Perhaps those elderly who travel in automobiles or walk the streets are "healthier" than those who are injured at home.

More questions have been raised by this study than have been answered. Additional research is needed to determine if the elderly are different from the young in their response to injury and, if so, how initial therapy should be modified to provide the best possible outcome for these individuals.

References

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  • 19. Bobb J: Unpublished data. Maryland Institute for Emergency Medical Services Systems, 1986.
  • 20. Maryland Institute for Emergency Medical Services Systems: Annual Report, Baltimore, 1985.
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10.3928/0098-9134-19871101-08

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