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Lawn mower injuries to children in Pennsylvania, 1989 to 1993
Lawn Mower Injuries to Children in Pennsylvania, 1989 to 1993 Lisa Marie Bernardo, RN, PhD, CEN, and Mary Jane Gardner, RN
Lawn mowers pose a significant risk of morbidity and mortality to children. The purpose of this study was to identify the characteristics of children injured by lawn mowers admitted to accredited trauma centers in Pennsylvania from 1989 to 1993. Data were available on 177 children who sustained 504 injuries. The majority of children were less than 5 years old, male, injured by a power mower, during the summer, at home, and with an injury to an extremity. Four cases that represent patients with a low Injury Severity Score but a long hospitalization are discussed. (INT J TRAUMA NURS 1996;2:36-41)
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t is estimated that more than 7 million lawn m o w e r s are purchased each year in the United States, 1 and an estimated 7.65 million are in operation annually. 2 In 1992 the U.S. C o n s u m e r Product Safety Commission (USCPSC) estimated 135,000 individuals were treated in emerg e n c y d e p a r t m e n t s for injuries associated with p o w e r lawn and g a r d e n tools, including p o w e r mowers. P o w e r m o w e r s are responsible for an estimated 55,000 to 60,000 injuries annually. 3 There are a limited n u m b e r of reports in the literature on lawn m o w e r injuries in children. 1,4-8 Lawn m o w e r s cause lacerations, fractures, and amputations of fingers and toes. P o w e r and riding m o w e r s are the m o s t frequent source of injury, and a n u m b e r of children are injured as bystand-
Lisa Marie Bernardo is a clinical nurse specialist in the emergency departmentand an adjunctassistantprofessor, University of Pittsburgh School of Nursing. Mary Jane Gardner is a program manager,BenedumPediatricTraumaand Nutritional Support Programs, Children's Hospital of Pittsburgh,
Presentedas a posterat the Global Child Health 2000 Conference, Vancouver,Canada,June 1995. For reprints write Lisa Marie Bernardo, RN, PhD, CEN, Children's Hospital of Pittsburgh, One Children's Place, Pittsburgh, PA 15213. Copyright 9 1996 by the EmergencyNursesAssociation.
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ers w h e n they are run over or slip u n d e r a moving lawn mower. Young children are at risk for bystander injury b e c a u s e they lack visual d e p t h perception and have immature m o t o r skills and no p e r c e p t i o n of potential injury and its p e r m a n e n t consequences. 8 Many y o u n g children w h o are held by adults on riding lawn m o w e r s or garden tractors fall from the m o w e r into its path, leading to severe injuries to the limbs, torso, and head. These injuries can require reconstructive surgery and long-term rehabilitation and can result in permanent disability.
. . . injuries can require reconstructive surgery and long-term rehabilitation and can result in permanent disability.
Most published studies focus on small sample populations and cite institutional-specific data. In an effort to evaluate characteristics of a larger sample, the state-wide Pennsylvania Trauma Outcome Study (PTOS) was consulted. The PTOS is a registry maintained by the Pennsylvania Trauma
INTERNATIONAL JOURNAL OF TRAUMA NURSING/Bernardo and Gardner
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Systems Foundation. Since October 1986 through the conclusion of its ninth year over 160,000 patients have been entered into the PTOS database. 9 Patients are entered if they meet the PTOS definition for major trauma. The purpose of this study was to identify the frequency and type of injuries sustained by children injured in lawn m o w e r - r e lated injuries admitted to a Pennsylvania trauma center in a selected time period. Data were obtained from the PTOS, which reflects admissions to the 25 accredited trauma centers in Pennsylvania. It does not include other hospitals in the state or injuries for the general population.
METHODS Patients for this study were selected from the PTOS if they were injured in a lawn mower-related incident between January 1, 1989, through December 31, 1993. The data selected for analysis are listed in Table 1. Data were analyzed by use of descriptive statistics and the Pearson product-moment correlation.
RESULTS During the study period 652 individuals of all ages were admitted to Pennsylvania trauma centers for injuries sustained from lawn mowers. Of those cases, 190 were children 1 to 18 years old (29% of the population). Complete External Cause of Injury (E-code) and injury description data were available on 177 cases, which were used for the basis of this analysis.
Age The average age of the injured children was 7.90 years (SD 5.52 years). The age range was 1 to 18 years. Eighty-five (48%) of the injured children were 5 years old or younger.
Gender A total of 135 males (76%) and 42 (24%) females 18 years old or y o u n g e r had been injured.
Mechanism of Injury
Table 1. Data analyzed for study 1. Age: patients _<18years old 2. Gender 3. Mechanism of injury--external cause of injury (E-codes) E 919.8--riding mower E 920.0--power mower E 920.4--non-power mower 4. Date of injury 5. Geographic location of injury 6. Types of injury--International Classification of Diseases, Ninth Revision, Clinical Manual Codes (ICD-9-CM) 7. Injury severity Injury Severity Score (ISS) 8. Outcome measure--Functional Independence Measurement Score (FIM) 9. Trauma center activities Post emergency department destination Admitting physician Length of stay in intensive care unit and hospital
Geographic Location of Injury Most children were injured at their homes (n = 132, 75%).
Types of Injury The most frequent injuries were traumatic amputation of the toes without complications (n = 54), fractures of one or more phalanges of the foot ( n = 39), traumatic amputation (complete or partial) of the fingers without complications (n = 20), and unilateral amputation of the foot (n = 20). Figure 1 categorizes and summarizes the number of injuries. Of the 504 injuries, there were 177 open or closed skeletal fractures, 153 soft tissue injuries (lacerations, abrasions, contusions to all b o d y areas, primarily the extremities), 113 amputations of digits or extremities, 31 neurovascular injuries, 10 organ injuries, including o p e n cerebral laceration, and 20 miscellaneous injuries.
Injury Severity
Power mowers were the cause of injury in 122 cases (69%), riding lawn mowers in 51 cases (29%), and non-power mowers in 4 cases (2%). The PTOS did not specify whether the child was a passenger, operator, or bystander when injured.
Injury Severity Scores (ISS) ranged from 1 to 26. The majority of cases (n =156, 88%) had an ISS <10. There was an inverse correlation between age and ISS ( r = -0.38).
Date of Injury
Outcome Measures
Injuries occurred most often during May (n = 44), June (n = 34), and August (n = 21).
Functional I n d e p e n d e n c e Measurement (FIM) scores were available for only 108 (57%) of the
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180160140 120100 80 60 40
//
20
0
I Amputation
Skeletal Fractures
Soft Tissue
Head Injury
Organ
~ - m t Neurovascular
Misc
Figure 1. Distribution of types of pediatric injuries found with lawn mowers, Pennsylvania Trauma Outcome Study, 1989 to 1993. sample. The most frequent areas for d e p e n d e n c e were locomotion (n = 80, 74%) and transfer mobilities (n = 70, 65%). The only death was that of an 8year-old b o y w h o fell under a riding lawn mower, sustaining o p e n cerebral lacerations and chest and abdominal injuries.
T r a u m a C e n t e r Activities The majority of patients (n = 145, 82%) were transferred from the emergency department directly to the operating room. The admitting physician was an orthopedic surgeon in 83 (47%) of the cases, a trauma surgeon in 34 (19%) cases, a neurosurgeon in 1 (0.5%) case, and other services in the remaining cases. Length of stay in the intensive care unit ranged from 0 to 8 days (mean 0.67 days, SD 1.6 days). Total hospitalization days ranged from 0 (a death) to 48 days (mean 9.60 days, SD 8.7 days, median 6 days). The majority of patients (n = 124) had a total length of stay of <10 days, with a mean of 5.17 days.
DISCUSSION The findings of this study are comparable to those reported by other investigators. The percentage of patients w h o are children sustaining lawn m o w e r injuries was similar to previous reports of 37%, ~45%, 3 and 33%) 0 The m e a n age of 7.90 years of the PTOS patients was older than the m e a n ages in some studies, 4.2 years, ~ 4.6 years, 6 and 5 and 12 years7 Sev38
eral of these studies 1,6 did not have patients older than 13 years in their samples. The p r e d o m i n a n c e of males in this study (n = 135, 76%) was slightly higher than reported by other researchers, which ranged from a low of 61% 5 to a high of 70%. 4,6 Power mowers were the most c o m m o n cause of injuries in the current study and in others. 4,7,8 The average lawn m o w e r has a 26-inch, 3.5-pound rotary blade that rotates at 3000 revolutions per minute. The m o m e n t u m of a spinning blade equals that of a 1.17-pound weight traveling at 232 miles per hour. 11 The lawn mower's spinning blades cut through soft tissue and bone, producing fractures, amputations, lacerations, and avulsion of soft tissue. The blade allows dirt, grass, and debris to enter the wound. The frequency of extremity fracture and digit amputation found in this study was similar to that previously described52,13 Although the ISS tends to be low, these injuries are not minor because they are debilitating and costly to treat. An amputated digit is not considered a life-threatening injury, yet it may require the specialized services of replantation and microscopic surgery, c o m m o n l y found in a trauma center. Even small wounds can cause significant blood loss for a child because of the child's larger b o d y surface a r e a - t o - m a s s ratio. For example, a leg injury in an adult would constitute a small percentage of b o d y surface area. A similar injury in a y o u n g child constitutes a larger surface-to-mass
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injury and places the child at risk for hypovolemia. The average length of stay in the intensive care unit was <1 day; however, there were three patients w h o required intensive care unit stays of 8 days. Table 3 provides more detail about each case to demonstrate the magnitude of an injury that ,nay not be reflected by the ISS. The majority of cases tended to have a length of hospital stay in the range of 1 to 10 days (n = 124, 70%). Case 4 in Table 2 is an example of a child with an extensive hospital stay yet a low ISS. This length of stay was similar to that in other reports.~.7.'~An average 9-day length of stay may reflect the child's need for more hospital services with this type of injury. The p o s t - e m e r g e n c y department destination was evaluated to estimate the type of services lawn m o w e r w o u n d s required for initial treatment. The majority (82%) of patients in this study a p p e a r e d to require emergency surgery because they were transferred directly to the operating room. Given the nature of most lawn m o w e r wounds, it would appear this n u m b e r would be higher than reflected by this data point. In actuality, more patients m a y have received e m e r g e n c y surgery than this figure reflects because of the practices of different trauma centers. Patients may be transferred within the hospital to s p e c i a l i z e d d i a g n o s t i c s e r v i c e s (i.e., angiography) or to inpatient trauma areas for further evaluation and stabilization before surgery. The admitting physician was evaluated to determine the type of medical specialty that was required for m a n a g e m e n t of lawn m o w e r wounds. Orthopedic surgery was the primary admitting service for this sample. Despite the p r e d o m i n a n c e of orthopedic wounds, the admitting physician can vary a m o n g trauma centers. For example, a trauma center's protocol may use plastic surgery for hand trauma or admit all patients to the trauma service with subsequent subspecialty consultation. The long-term consequences of a serious extremity injury may affect long-term rehabilitation needs. The FIM criteria are calculated on discharge; however, subsequent outcome information is not collected in the PTOS. Without further data it is difficult to speculate on a child's future progress in locomotion and transfer mobilities. It can be safe to assume a casted extremity will interfere with locomotion, mobility, and activities of daily living. However, once the cast is removed, activities may return to normal. It can also be surmised that some children with an amputation or other severe injury would require a prosthesis or additional rehabilitation services. The limitations of this study are related to the use of large databases for analyses. The chance for bias APRIL-JUNE 1996
Table 2. Case reviews of children with extensive length of stay
Case 1. A 1-year-old girl fell off a riding lawn mower and was run over. This child sustained an unilateral traumatic amputation of the foot and injury to the posterior tibial nerve. Her ISS was 9. She was hospitalized for 16 days. On discharge her FIM score showed independence with feeding and expression but complete dependence with locomotion (required maximum assistance with walking or was restricted to bed) and modified dependence with transfer mobility (required assistance to use an adaptive device). Case 2. A 3-year-old boy was run over by a lawn mower at home. His injuries were an open fracture of the skull vault with loss of consciousness, a cerebral laceration with an open intracranial wound, and an injury to a blood vessel in the head and neck. His ISS was 16. He spent 19 days in the hospital. No FIM score was reported for this patient. Case 3. A 6-year-old boy was run over by a lawn tractor at home. His injuries were an open fracture of the calcaneus and an open wound of the knee, leg, and ankle. His ISS was 8. He spent 37 days in the hospital. His FIM score showed complete independence with feeding but required complete dependence with locomotion (maximum assistance to walk or bed restricted), modified dependence with expression, and modified dependence with transfer mobility (required assistance with adaptive device). Case 4. A 4-year-old boy was run over by a lawn mower at home. His injuries were a unilateral below-the-knee amputation and an open fracture of the femoral condyle. His ISS was 9. He was hospitalized for 48 days. His FIM score showed independence with (1) feeding (using a device), (2) locomotion (with a device such as crutches, orthosis, prosthesis), (3) expression, and (4) mobility (with a device for mobility, such as crutches.)
exists in the potential miSclassification of data. Incomplete patient data for retrieval and analysis can bias the results. This database does not include adults or children treated at non-trauma centers; therefore it cannot be used to predict the frequency of pediatric lawn m o w e r injuries in the general population.
PREVENTION A c o m m o n - s e n s e a p p r o a c h is necessary to prevent lawn m o w e r injuries. Proper lawn m o w e r maintenance, coupled with proper operator safety, provide for safe m o w e r operation.
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Lawn Mower Maintenance
presence control, higher seat back, and dynamic turn and sudden traction performance limits. 3 The American Academy of Pediatrics TM recommends that operators of riding mowers meet the same criteria developed for operators of all-terrain vehicles. Operators should be a minimum of 14 years old and have completed training that deals with the safe operation of the mower. Maturity, coordination, and good judgment are necessary for safe riding m o w e r Mower Operation operation.14 Children should not be passengers on either the The mowing area should be inspected for large mower seat or in a cart towed behind the mower. stones, nails, wire--objects that can become missiles Serious injury can result if the child falls off the mower and impale the operator or bystander. Under no ciror out of the cart. If it is necessary to m o w in recumstances should children or pets be permitted near verse, the operator should look behind for potenthe area of mower operation. Innocent bystanders tial dangers or bystanders. Operators of riding mowcan be hit with debris or run over by the mower. ers should m o w up and d o w n slopes to avoid rollIdeally, children less than 5 years old should be kept over incidents, as o p p o s e d to p o w e r m o w e r operaindoors during mowing. They should not be permittors, w h o should m o w across slopes. ted to walk alongside, in front of, or behind a movNurses can be active in preventing this needless ing mower. Children should not be permitted to play type of childhood injury. They can help develop or on or around mowers, even when they are not in present lawn mower use. TM clinics, publish newspaCurrently, there are no per articles, and prepare age or training requirements The American Academy of p u b l i c s e r v i c e anfor lawn mower operation. Pediatrics recommends that nouncements to educate Children should not operate operators of riding mowers consumers on the hazmowers, even with adult ards of improper lawn supervision, until age and should meet the same criteria m o w e r use. s There are instruction requirements are developed for operators of allmultiple c o n s u m e r reestablished and met. terrain vehicles. sources, such as The InPower Mowers jury Prevention Program (TIPP) sponsored by the As of June 30, 1982, all American A c a d e m y of p o w e r lawn mowers must Pediatrics, which highlights frequent causes of childmeet the federal standards for safety, which include h o o d injuries, including lawn mowers. The respecifications for blade brake control, foot shield, sources can be incorporated into local injury preand labels. 15 The USCPSC recommends that p o w e r vention programs. mowers should be operated on dry grass and the m o w e r should be pushed forward, never backward. CONCLUSION If a sloping lawn is mowed, the m o w e r should be m o v e d across the slope, never up and down. Work This study used a large database for studying inclothes, such as sturdy shoes with sure-grip soles juries to a pediatric population. It found that approxiand long pants, should be w o r n to minimize injury. mately one third of the Pennsylvanians admitted to Electric lawn mowers should have an extension an accredited trauma center during the study period cord that is in g o o d condition and be the right gauge for treatment from lawn mower injuries were chilfor the electrical current. It is preferred that the dren. Younger children were more severely injured m o w e r use a g r o u n d e d fault circuit interrupter eleccompared with older children. Children were most tric cord to protect against short circuits that could often injured by a power mower and sustained sericause electrical injury to the operator. ous injury that required hospitalization, reconstructive surgery, and rehabilitation. These findings are Riding Mowers similar to those cited in previously published literaSince July 1987 riding lawn mowers must comture. Nurses can promote lawn mower safety by teachply with USCPSC standards that call for operatoring safe mowing practices to families with children.
The operator should review the owner's manual and be familiar with the mower's use before starting it. The entire mower, especially the blades, should be checked routinely. The blades should be intact and sharp because dull m o w e r blades require a higher speed to work effectively. Sharp blades use a lower throttle speed. 11
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We thank the following individuals for their assistance: Carol Forrester-Staz, RN, Executive Director, Pennsylvania Trauma Systems Foundation (PTSF), for granting permission to use the PTOS data; Mary Ann Spott, NPA, RRA, CPHQ, Manager, Quality Assurance and Trauma Registry, PTSF, for assisting with data interpretation; and Craig Albanese, MD, and Kenneth D. Rogers, MD, Children's Hospital of Pittsburgh, for their thoughtful review of this manuscript.
REFERENCES 1. Letton RW, Chwals WJ. Patterns of power mower injuries in children compared with adults and the elderly. J Trauma 1994;37:182-6. 2. Smith E. Hazard analysis: ride-on mowers. Washington, DC: U.S. Consumer Product Safety Commission, 1988. 3. Anger DM, Ledbetter BR, Stasikelis PJ, Calhoun J. Injuries of the foot related to the use of lawn mowers. J Bone Joint Surg 1995;77A:719-25. 4. Grosfeld JL, Morse TS, Eyring EJ. Lawn mower injuries in children.Arch Surg 1970;100:582-3. 5. Ross PM, Schwentker EP, Bryan H. Mutilating lawn mower injuries in children. JAMA 1976;236:480-1.
6. Love SM, Grogan DP, Ogden JA. Lawn-mower injuries in children. J Orthop Trauma 1988;2:94-101. 7. Johnstone BR, Bennett CS. Lawn mower injuries in children. Aust N Z J Surg 1989;59:713-8. 8. Martin LI. Lawnmower injuries in children: destructive and preventable. Plast Surg Nurs 1990;10:69-70, 75-6. 9. Pennsylvania Trauma Systems Foundation. Operational manual for the Pennsylvania Data Base Collection System. Mechanicsburg, PA: PennsylvaniaTraumaSystems Foundation, 1995. 10. Corcoran J, Zamboni WA, Zook EG. Management of lawn mower injuries to the foot and ankle.Ann Plast Surg 1993;31:2204. 11. Park WH, DeMuth WE. Wounding capacity of rotary lawn mowers. JTrauma 1975;15:36-8. 12. Graham W, Miller S, Demuth W, Gordon S. Injuries from rotary power lawnmowers. Am Fam Physician 1976; 13:75-9. 13. Horowitz JH, Nichter LS, Kenney JG, Morgan RF. Lawnmower injuries in children: lower extremity reconstruction. J Trauma 1985;25:1138-46. 14. Committee on Accident and Poison Prevention. Ride-on mower injuries in children. Pediatrics 1990;86:141-3. 15. U.S. Consumer Product Safety Commission. Power lawnmowers. Washington, DC: Office of Information and Public Affairs, 1988. (Product fact sheet no 1.)
Availability of JOURNAL back issues As a service to our subscribers, copies of back issues of the INTERNATIONALJOURNAL OF TRAUMA NURSING for the preceding year are maintained and are available for purchase from the publisher, Mosby-Year Book, Inc., at a cost of $11.00 per issue. The following quantity discounts are available: one fourth off on quantities of 12 to 23 and one third off on quantities of 24 or more. Please write to Mosby-Year Book, Inc., Subscription Services, 11830 Westline Industrial Drive, St. Louis, MO 63146-3318 or call (800) 453-4351 or (314) 4534351 for information availability of particular issues. If back issues are unavailable from the publisher, photocopies of complete issues are available from University Microfilms International, 300 N. Zeeb Road, Ann Arbor, MI 48106-1346. Tel.: (313) 761-4700.
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Lawn mowers pose a significant risk of morbidity and mortality to children. The purpose of this study was to identify the characteristics of children injured by lawn mowers admitted to accredited trauma centers in Pennsylvania from 1989 to 1993. Data were available on 177 children who sustained 504 injuries. The majority of children were less than 5 years old, male, injured by a power mower, during the summer, at home, and with an injury to an extremity. Four cases that represent patients with a low Injury Severity Score but a long hospitalization are discussed. (INT J TRAUMA NURS 1996;2:36-41)
D
t is estimated that more than 7 million lawn m o w e r s are purchased each year in the United States, 1 and an estimated 7.65 million are in operation annually. 2 In 1992 the U.S. C o n s u m e r Product Safety Commission (USCPSC) estimated 135,000 individuals were treated in emerg e n c y d e p a r t m e n t s for injuries associated with p o w e r lawn and g a r d e n tools, including p o w e r mowers. P o w e r m o w e r s are responsible for an estimated 55,000 to 60,000 injuries annually. 3 There are a limited n u m b e r of reports in the literature on lawn m o w e r injuries in children. 1,4-8 Lawn m o w e r s cause lacerations, fractures, and amputations of fingers and toes. P o w e r and riding m o w e r s are the m o s t frequent source of injury, and a n u m b e r of children are injured as bystand-
Lisa Marie Bernardo is a clinical nurse specialist in the emergency departmentand an adjunctassistantprofessor, University of Pittsburgh School of Nursing. Mary Jane Gardner is a program manager,BenedumPediatricTraumaand Nutritional Support Programs, Children's Hospital of Pittsburgh,
Presentedas a posterat the Global Child Health 2000 Conference, Vancouver,Canada,June 1995. For reprints write Lisa Marie Bernardo, RN, PhD, CEN, Children's Hospital of Pittsburgh, One Children's Place, Pittsburgh, PA 15213. Copyright 9 1996 by the EmergencyNursesAssociation.
1075-4210/96$5.00 + 0 65/1/73162
36
ers w h e n they are run over or slip u n d e r a moving lawn mower. Young children are at risk for bystander injury b e c a u s e they lack visual d e p t h perception and have immature m o t o r skills and no p e r c e p t i o n of potential injury and its p e r m a n e n t consequences. 8 Many y o u n g children w h o are held by adults on riding lawn m o w e r s or garden tractors fall from the m o w e r into its path, leading to severe injuries to the limbs, torso, and head. These injuries can require reconstructive surgery and long-term rehabilitation and can result in permanent disability.
. . . injuries can require reconstructive surgery and long-term rehabilitation and can result in permanent disability.
Most published studies focus on small sample populations and cite institutional-specific data. In an effort to evaluate characteristics of a larger sample, the state-wide Pennsylvania Trauma Outcome Study (PTOS) was consulted. The PTOS is a registry maintained by the Pennsylvania Trauma
INTERNATIONAL JOURNAL OF TRAUMA NURSING/Bernardo and Gardner
VOLUME 2, NUMBER 2
Systems Foundation. Since October 1986 through the conclusion of its ninth year over 160,000 patients have been entered into the PTOS database. 9 Patients are entered if they meet the PTOS definition for major trauma. The purpose of this study was to identify the frequency and type of injuries sustained by children injured in lawn m o w e r - r e lated injuries admitted to a Pennsylvania trauma center in a selected time period. Data were obtained from the PTOS, which reflects admissions to the 25 accredited trauma centers in Pennsylvania. It does not include other hospitals in the state or injuries for the general population.
METHODS Patients for this study were selected from the PTOS if they were injured in a lawn mower-related incident between January 1, 1989, through December 31, 1993. The data selected for analysis are listed in Table 1. Data were analyzed by use of descriptive statistics and the Pearson product-moment correlation.
RESULTS During the study period 652 individuals of all ages were admitted to Pennsylvania trauma centers for injuries sustained from lawn mowers. Of those cases, 190 were children 1 to 18 years old (29% of the population). Complete External Cause of Injury (E-code) and injury description data were available on 177 cases, which were used for the basis of this analysis.
Age The average age of the injured children was 7.90 years (SD 5.52 years). The age range was 1 to 18 years. Eighty-five (48%) of the injured children were 5 years old or younger.
Gender A total of 135 males (76%) and 42 (24%) females 18 years old or y o u n g e r had been injured.
Mechanism of Injury
Table 1. Data analyzed for study 1. Age: patients _<18years old 2. Gender 3. Mechanism of injury--external cause of injury (E-codes) E 919.8--riding mower E 920.0--power mower E 920.4--non-power mower 4. Date of injury 5. Geographic location of injury 6. Types of injury--International Classification of Diseases, Ninth Revision, Clinical Manual Codes (ICD-9-CM) 7. Injury severity Injury Severity Score (ISS) 8. Outcome measure--Functional Independence Measurement Score (FIM) 9. Trauma center activities Post emergency department destination Admitting physician Length of stay in intensive care unit and hospital
Geographic Location of Injury Most children were injured at their homes (n = 132, 75%).
Types of Injury The most frequent injuries were traumatic amputation of the toes without complications (n = 54), fractures of one or more phalanges of the foot ( n = 39), traumatic amputation (complete or partial) of the fingers without complications (n = 20), and unilateral amputation of the foot (n = 20). Figure 1 categorizes and summarizes the number of injuries. Of the 504 injuries, there were 177 open or closed skeletal fractures, 153 soft tissue injuries (lacerations, abrasions, contusions to all b o d y areas, primarily the extremities), 113 amputations of digits or extremities, 31 neurovascular injuries, 10 organ injuries, including o p e n cerebral laceration, and 20 miscellaneous injuries.
Injury Severity
Power mowers were the cause of injury in 122 cases (69%), riding lawn mowers in 51 cases (29%), and non-power mowers in 4 cases (2%). The PTOS did not specify whether the child was a passenger, operator, or bystander when injured.
Injury Severity Scores (ISS) ranged from 1 to 26. The majority of cases (n =156, 88%) had an ISS <10. There was an inverse correlation between age and ISS ( r = -0.38).
Date of Injury
Outcome Measures
Injuries occurred most often during May (n = 44), June (n = 34), and August (n = 21).
Functional I n d e p e n d e n c e Measurement (FIM) scores were available for only 108 (57%) of the
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180160140 120100 80 60 40
//
20
0
I Amputation
Skeletal Fractures
Soft Tissue
Head Injury
Organ
~ - m t Neurovascular
Misc
Figure 1. Distribution of types of pediatric injuries found with lawn mowers, Pennsylvania Trauma Outcome Study, 1989 to 1993. sample. The most frequent areas for d e p e n d e n c e were locomotion (n = 80, 74%) and transfer mobilities (n = 70, 65%). The only death was that of an 8year-old b o y w h o fell under a riding lawn mower, sustaining o p e n cerebral lacerations and chest and abdominal injuries.
T r a u m a C e n t e r Activities The majority of patients (n = 145, 82%) were transferred from the emergency department directly to the operating room. The admitting physician was an orthopedic surgeon in 83 (47%) of the cases, a trauma surgeon in 34 (19%) cases, a neurosurgeon in 1 (0.5%) case, and other services in the remaining cases. Length of stay in the intensive care unit ranged from 0 to 8 days (mean 0.67 days, SD 1.6 days). Total hospitalization days ranged from 0 (a death) to 48 days (mean 9.60 days, SD 8.7 days, median 6 days). The majority of patients (n = 124) had a total length of stay of <10 days, with a mean of 5.17 days.
DISCUSSION The findings of this study are comparable to those reported by other investigators. The percentage of patients w h o are children sustaining lawn m o w e r injuries was similar to previous reports of 37%, ~45%, 3 and 33%) 0 The m e a n age of 7.90 years of the PTOS patients was older than the m e a n ages in some studies, 4.2 years, ~ 4.6 years, 6 and 5 and 12 years7 Sev38
eral of these studies 1,6 did not have patients older than 13 years in their samples. The p r e d o m i n a n c e of males in this study (n = 135, 76%) was slightly higher than reported by other researchers, which ranged from a low of 61% 5 to a high of 70%. 4,6 Power mowers were the most c o m m o n cause of injuries in the current study and in others. 4,7,8 The average lawn m o w e r has a 26-inch, 3.5-pound rotary blade that rotates at 3000 revolutions per minute. The m o m e n t u m of a spinning blade equals that of a 1.17-pound weight traveling at 232 miles per hour. 11 The lawn mower's spinning blades cut through soft tissue and bone, producing fractures, amputations, lacerations, and avulsion of soft tissue. The blade allows dirt, grass, and debris to enter the wound. The frequency of extremity fracture and digit amputation found in this study was similar to that previously described52,13 Although the ISS tends to be low, these injuries are not minor because they are debilitating and costly to treat. An amputated digit is not considered a life-threatening injury, yet it may require the specialized services of replantation and microscopic surgery, c o m m o n l y found in a trauma center. Even small wounds can cause significant blood loss for a child because of the child's larger b o d y surface a r e a - t o - m a s s ratio. For example, a leg injury in an adult would constitute a small percentage of b o d y surface area. A similar injury in a y o u n g child constitutes a larger surface-to-mass
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injury and places the child at risk for hypovolemia. The average length of stay in the intensive care unit was <1 day; however, there were three patients w h o required intensive care unit stays of 8 days. Table 3 provides more detail about each case to demonstrate the magnitude of an injury that ,nay not be reflected by the ISS. The majority of cases tended to have a length of hospital stay in the range of 1 to 10 days (n = 124, 70%). Case 4 in Table 2 is an example of a child with an extensive hospital stay yet a low ISS. This length of stay was similar to that in other reports.~.7.'~An average 9-day length of stay may reflect the child's need for more hospital services with this type of injury. The p o s t - e m e r g e n c y department destination was evaluated to estimate the type of services lawn m o w e r w o u n d s required for initial treatment. The majority (82%) of patients in this study a p p e a r e d to require emergency surgery because they were transferred directly to the operating room. Given the nature of most lawn m o w e r wounds, it would appear this n u m b e r would be higher than reflected by this data point. In actuality, more patients m a y have received e m e r g e n c y surgery than this figure reflects because of the practices of different trauma centers. Patients may be transferred within the hospital to s p e c i a l i z e d d i a g n o s t i c s e r v i c e s (i.e., angiography) or to inpatient trauma areas for further evaluation and stabilization before surgery. The admitting physician was evaluated to determine the type of medical specialty that was required for m a n a g e m e n t of lawn m o w e r wounds. Orthopedic surgery was the primary admitting service for this sample. Despite the p r e d o m i n a n c e of orthopedic wounds, the admitting physician can vary a m o n g trauma centers. For example, a trauma center's protocol may use plastic surgery for hand trauma or admit all patients to the trauma service with subsequent subspecialty consultation. The long-term consequences of a serious extremity injury may affect long-term rehabilitation needs. The FIM criteria are calculated on discharge; however, subsequent outcome information is not collected in the PTOS. Without further data it is difficult to speculate on a child's future progress in locomotion and transfer mobilities. It can be safe to assume a casted extremity will interfere with locomotion, mobility, and activities of daily living. However, once the cast is removed, activities may return to normal. It can also be surmised that some children with an amputation or other severe injury would require a prosthesis or additional rehabilitation services. The limitations of this study are related to the use of large databases for analyses. The chance for bias APRIL-JUNE 1996
Table 2. Case reviews of children with extensive length of stay
Case 1. A 1-year-old girl fell off a riding lawn mower and was run over. This child sustained an unilateral traumatic amputation of the foot and injury to the posterior tibial nerve. Her ISS was 9. She was hospitalized for 16 days. On discharge her FIM score showed independence with feeding and expression but complete dependence with locomotion (required maximum assistance with walking or was restricted to bed) and modified dependence with transfer mobility (required assistance to use an adaptive device). Case 2. A 3-year-old boy was run over by a lawn mower at home. His injuries were an open fracture of the skull vault with loss of consciousness, a cerebral laceration with an open intracranial wound, and an injury to a blood vessel in the head and neck. His ISS was 16. He spent 19 days in the hospital. No FIM score was reported for this patient. Case 3. A 6-year-old boy was run over by a lawn tractor at home. His injuries were an open fracture of the calcaneus and an open wound of the knee, leg, and ankle. His ISS was 8. He spent 37 days in the hospital. His FIM score showed complete independence with feeding but required complete dependence with locomotion (maximum assistance to walk or bed restricted), modified dependence with expression, and modified dependence with transfer mobility (required assistance with adaptive device). Case 4. A 4-year-old boy was run over by a lawn mower at home. His injuries were a unilateral below-the-knee amputation and an open fracture of the femoral condyle. His ISS was 9. He was hospitalized for 48 days. His FIM score showed independence with (1) feeding (using a device), (2) locomotion (with a device such as crutches, orthosis, prosthesis), (3) expression, and (4) mobility (with a device for mobility, such as crutches.)
exists in the potential miSclassification of data. Incomplete patient data for retrieval and analysis can bias the results. This database does not include adults or children treated at non-trauma centers; therefore it cannot be used to predict the frequency of pediatric lawn m o w e r injuries in the general population.
PREVENTION A c o m m o n - s e n s e a p p r o a c h is necessary to prevent lawn m o w e r injuries. Proper lawn m o w e r maintenance, coupled with proper operator safety, provide for safe m o w e r operation.
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Lawn Mower Maintenance
presence control, higher seat back, and dynamic turn and sudden traction performance limits. 3 The American Academy of Pediatrics TM recommends that operators of riding mowers meet the same criteria developed for operators of all-terrain vehicles. Operators should be a minimum of 14 years old and have completed training that deals with the safe operation of the mower. Maturity, coordination, and good judgment are necessary for safe riding m o w e r Mower Operation operation.14 Children should not be passengers on either the The mowing area should be inspected for large mower seat or in a cart towed behind the mower. stones, nails, wire--objects that can become missiles Serious injury can result if the child falls off the mower and impale the operator or bystander. Under no ciror out of the cart. If it is necessary to m o w in recumstances should children or pets be permitted near verse, the operator should look behind for potenthe area of mower operation. Innocent bystanders tial dangers or bystanders. Operators of riding mowcan be hit with debris or run over by the mower. ers should m o w up and d o w n slopes to avoid rollIdeally, children less than 5 years old should be kept over incidents, as o p p o s e d to p o w e r m o w e r operaindoors during mowing. They should not be permittors, w h o should m o w across slopes. ted to walk alongside, in front of, or behind a movNurses can be active in preventing this needless ing mower. Children should not be permitted to play type of childhood injury. They can help develop or on or around mowers, even when they are not in present lawn mower use. TM clinics, publish newspaCurrently, there are no per articles, and prepare age or training requirements The American Academy of p u b l i c s e r v i c e anfor lawn mower operation. Pediatrics recommends that nouncements to educate Children should not operate operators of riding mowers consumers on the hazmowers, even with adult ards of improper lawn supervision, until age and should meet the same criteria m o w e r use. s There are instruction requirements are developed for operators of allmultiple c o n s u m e r reestablished and met. terrain vehicles. sources, such as The InPower Mowers jury Prevention Program (TIPP) sponsored by the As of June 30, 1982, all American A c a d e m y of p o w e r lawn mowers must Pediatrics, which highlights frequent causes of childmeet the federal standards for safety, which include h o o d injuries, including lawn mowers. The respecifications for blade brake control, foot shield, sources can be incorporated into local injury preand labels. 15 The USCPSC recommends that p o w e r vention programs. mowers should be operated on dry grass and the m o w e r should be pushed forward, never backward. CONCLUSION If a sloping lawn is mowed, the m o w e r should be m o v e d across the slope, never up and down. Work This study used a large database for studying inclothes, such as sturdy shoes with sure-grip soles juries to a pediatric population. It found that approxiand long pants, should be w o r n to minimize injury. mately one third of the Pennsylvanians admitted to Electric lawn mowers should have an extension an accredited trauma center during the study period cord that is in g o o d condition and be the right gauge for treatment from lawn mower injuries were chilfor the electrical current. It is preferred that the dren. Younger children were more severely injured m o w e r use a g r o u n d e d fault circuit interrupter eleccompared with older children. Children were most tric cord to protect against short circuits that could often injured by a power mower and sustained sericause electrical injury to the operator. ous injury that required hospitalization, reconstructive surgery, and rehabilitation. These findings are Riding Mowers similar to those cited in previously published literaSince July 1987 riding lawn mowers must comture. Nurses can promote lawn mower safety by teachply with USCPSC standards that call for operatoring safe mowing practices to families with children.
The operator should review the owner's manual and be familiar with the mower's use before starting it. The entire mower, especially the blades, should be checked routinely. The blades should be intact and sharp because dull m o w e r blades require a higher speed to work effectively. Sharp blades use a lower throttle speed. 11
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We thank the following individuals for their assistance: Carol Forrester-Staz, RN, Executive Director, Pennsylvania Trauma Systems Foundation (PTSF), for granting permission to use the PTOS data; Mary Ann Spott, NPA, RRA, CPHQ, Manager, Quality Assurance and Trauma Registry, PTSF, for assisting with data interpretation; and Craig Albanese, MD, and Kenneth D. Rogers, MD, Children's Hospital of Pittsburgh, for their thoughtful review of this manuscript.
REFERENCES 1. Letton RW, Chwals WJ. Patterns of power mower injuries in children compared with adults and the elderly. J Trauma 1994;37:182-6. 2. Smith E. Hazard analysis: ride-on mowers. Washington, DC: U.S. Consumer Product Safety Commission, 1988. 3. Anger DM, Ledbetter BR, Stasikelis PJ, Calhoun J. Injuries of the foot related to the use of lawn mowers. J Bone Joint Surg 1995;77A:719-25. 4. Grosfeld JL, Morse TS, Eyring EJ. Lawn mower injuries in children.Arch Surg 1970;100:582-3. 5. Ross PM, Schwentker EP, Bryan H. Mutilating lawn mower injuries in children. JAMA 1976;236:480-1.
6. Love SM, Grogan DP, Ogden JA. Lawn-mower injuries in children. J Orthop Trauma 1988;2:94-101. 7. Johnstone BR, Bennett CS. Lawn mower injuries in children. Aust N Z J Surg 1989;59:713-8. 8. Martin LI. Lawnmower injuries in children: destructive and preventable. Plast Surg Nurs 1990;10:69-70, 75-6. 9. Pennsylvania Trauma Systems Foundation. Operational manual for the Pennsylvania Data Base Collection System. Mechanicsburg, PA: PennsylvaniaTraumaSystems Foundation, 1995. 10. Corcoran J, Zamboni WA, Zook EG. Management of lawn mower injuries to the foot and ankle.Ann Plast Surg 1993;31:2204. 11. Park WH, DeMuth WE. Wounding capacity of rotary lawn mowers. JTrauma 1975;15:36-8. 12. Graham W, Miller S, Demuth W, Gordon S. Injuries from rotary power lawnmowers. Am Fam Physician 1976; 13:75-9. 13. Horowitz JH, Nichter LS, Kenney JG, Morgan RF. Lawnmower injuries in children: lower extremity reconstruction. J Trauma 1985;25:1138-46. 14. Committee on Accident and Poison Prevention. Ride-on mower injuries in children. Pediatrics 1990;86:141-3. 15. U.S. Consumer Product Safety Commission. Power lawnmowers. Washington, DC: Office of Information and Public Affairs, 1988. (Product fact sheet no 1.)
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APRIL-JUNE 1996
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