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Pediatric head injury: The critical role of the emergency physician
ORIGINAL CONTRIBUTION injury, head, pediatric
Pediatric Head Injury: The Critical Role of the Emergency Physician Neurologic injury is a significant source of morbidity and mortality in pediatric patients. In order to clarify the factors influencing outcome in pediatric patients with severe head injury, we studied 200 consecutive patients with Glasgow Coma Scale (GCS) scores of 8 or less. The following data were collected: age, GCS score, presence of mass lesions, oculovestibular reflexes (OVR), pupillary size and reactivity, intracranial pressure (ICP), apnea, presence of hypotension, hypoxia (PO 2 < 60 torr), or hypercarbia (PCO 2 ~ 35 torr), presence of multiple trauma, and Modified Injury Severity Scale (MISS) score. Outcome was assessed by the Glasgow Outcome Scale at a m i n i m u m of six months following recovery. Of the 200 patients in the study, 86 (43%) had isolated head injury (IHI) and 114 (57%) had head injury plus multiple trauma (HI + MT). Overall, 26% of patients had mass lesions; 28% had altered OVR; 33% had fixed, dilated pupils; 79% had increased intracranial pressure; and 29% had hypotension, hypoxia, or hypercarbia. Overall mortality was 21.5%. Severity of injury (as judged by presence of mass lesions, GCS, OVR, fixed pupils) was more pronounced in patients with 1141, although increased ICP was more common in patients with HI + MT; however, death was almost three times more common in patients with HI + M T (30% versus 10.5%). In the IHI group, two of nine patients who died (22%) had hypotension, hypoxia, or hypercarbia; all but four patients (88%) in the HI + M T group had hypotension, hypoxia, or hypercarbia. GCS of 4 or less, increased ICP, MISS score less than 25, and presence of hypotension, hypoxia, or hypercarbia correlated significantly with outcome (P < .0I). Mass lesions did not correlate with outcome. These data indicate that overall mortality from severe head injury in pediatric patients is relatively low (21.5%). The majority of deaths, however, were associated either with extremely severe initial injury or with increased intracrania] pressure, severe multiple trauma, or presence of hypotension, hypoxia, or hypercarbia. Thus although the primary impact injury dictates outcome for some pediatric patients, m a n y patients die of the secondary injury. Early therapy aimed at preventing the secondary injury can have a significant effect on outcome. In this sense, the emergency physician m a y be as important in determining outcome as is the neurosurgeon. [Mayer TA, Walker ML: Pediatric head injury: The critical role of the emergency physician. Ann Emerg Med December 1985;14:1178-1184.]
Thorn A Mayer, MD* Fort Lauderdale, Florida Marion L Walker, MDt Salt Lake City, Utah From the Department of Emergency Medicine, North Broward Hospital District, and Coastal Emergency Services, Fort Lauderdale, Florida;* and the Department of Pediatric Neurosurgery, Primary Children's Medical Center, Salt Lake City, Utah.t Received for publication May 29, 1984. Revision received July 12, 1985. Accepted for publication July 25, 1985. Presented at the University Association for Emergency Medicine Annual Meeting in Louisville, Kentucky, May 1984. Address for reprints: Thom A Mayer, MD, 2200 West Commercial Boulevard, Suite 203, Fort Lauderdale, Florida 33309.
INTRODUCTION For physicians caring for pediatric patients, it is impossible to overstate the importance of head trauma. Trauma is the number one killer of children between the ages of 1 and 14, accounting for more than 50% of all deaths, and is the third leading cause of death for children less than one year old. 2 Neurologic injury is present in almost 80% of children with trauma, and is a major cause of morbidity and mortality.3 In all reported series of trauma deaths in Children, head injury has been a major factor affecting outcome.g-6 Despite the grim toll that head injury exacts among children, studies during the past several years in both adult and pediatric patients have clarified numerous areas in the field of head injury. Among these, three are particularly important. First, the mortality from severe head injury is decreasing. A 1977 report of a multicenter, international head injury study of patients treat14:12 December 1985
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ed from 1968 to 1974 indicated that the mortality rate for severe head injury in adults ranged from 49% to 52% among four participating centers. 7 More recent studies of similar patients have indicated mortalities of 36% to 41% 8-1o in adults and 10% to 20% mortality in children.n-14 This apparent improvement in o u t c o m e among severely head-injured patients is due to a number of factors, including increasing accessibility of definitive neurosurgical care, better prehospital care of head-injured patients, advances in monitoring and control of intracranial pressure (ICP), and early, appropriate diagnosis and therapy of both head injuries and associated injuries. Second, as diagnosis and therapy of severe head injury have improved, the concept of primary versus secondary brain injury has increased in importance. 15 Primary brain injury occurs at the time of initial impact and may involve, to varying degrees, axonal stretching and shearing (producing classical Strich lesions 16 in the brain), brain laceration, contusion, and vascular damage that will resuk in later hematoma formation. The secondary injury occurs after the initial impact injury and involves both the brain's response and the systemic response to trauma. The brain's response is a dynamic process involving loss of cerebral autoregulation, development of both extracellular and intracellular brain edema, breakdown of the blood brain barrier and, in some cases, coalescence of intracranial hemorrhage. The systemic response to trauma is largely cardiovascular and pulmonary in nature. Hypertension, hypotension, hypoxia, hypercarbia, and diminished cardiac output all may be present and further increase brain damage. Lastly, significant differences exist between adult and pediatric patients with severe head injury. Children have a much lower incidence of intracranial mass lesions following head trauma. In adult series, 40% to 50% of all patients have significant mass lesions, s-lo versus only 30% in children. 11-12 Conversely, intracranial hypertension is much more common in children than in adults. Only 40% to 50% of adult patients suffer significantly elevated ICP (ICP > 20 torr) following head injury; 80% of children have elevated ICE 17 Recent mortality in adult patients with severe head injuries ranges from 36% to 78/1179
41%, versus 10% to 20% mortality in children with similar injuries. 8qa With these facts in mind, we prospectively studied 200 pediatric patients with severe head injury in order to further clarify factors associated with outcome in pediatric patients, as well as differences between adult head injury studies and those in children.
METHODS During a four-year period (January 1978 through December 1981), 200 children who fulfilled the International Data Bank (if)B) criteriaT, 18 for severe head injury were treated at Prim a r y C h i l d r e n ' s Medical Center. These criteria were unconsciousness for more than six hours with inability to obey commands, utter recognizable words, or open the eyes, which corresponds to Glasgow Coma Scale (GCS) scores of 8 or less. Because of difficulty in applying the GCS verbal score in the preverbal age group, any child less than three years old who cried was given a m a x i m u m verbal score. Patients with a lucid interval were included only if they were unconscious for more than six hours following the lucid interval. Patients who were delayed in reaching our institution were included only if unconsciousness at our trauma center exceeded six hours. Each patient was classified prospectively according to age, sex, mechanism of injury, and severity of injury. The severity of head injury was assessed by using the GCS, pupillary light reflexes, altered oculovestibular reflexes (OVR}, presence of elevated intracranial pressure (ICP > 20 torr), or the presence of a surgical mass lesion. All surgical mass lesions were defined either at operation or by computed tomographic (CT) scan as a focal lesion causing midline shift of more than 5mm, resulting in surgical treatment. Focal edematous masses or intracerebral h e m a t o m a s were not considered surgical masses if the ICP was normal or was controlled easily. Severity of s y s t e m i c injury was judged by the Modified Injury Severity Scale (MISS) score. 19 This scale, which has been described previously, uses the Abbreviated Injury Scale-1980 classification (AIS-80} 2o except for head injuries. The MISS grades for head injury use the GCS score plus the presence of surgical mass lesions, pupillary response, and altered OVR for classification.19,21 Additional factors assessed in the Annals of Emergency Medicine
TABLE 1. Severe head injury: Overall data Category t i l l + MT
% 43 57
Mass lesions $ OVR Pupils
26 28 33
§ ICP > 20 tort Systemic complications
79 29
* IHI
Mortality 21.5 * Isolated head injury. t Head injury associated with multiple trauma. *Abnormal oculovestibular reflexes. Intracranial pressure.
overall severity of injury included the presence of hypotension (blood pressure ~< 80 + [2 x age in years]; hypoxemia (PO2 < 60 torr); or hypercarbia (PCO 2 i> 35 torr). Each of these criteria was based on ED determinations. All patients with any of these factors were managed aggressively with isotonic fluid and blood infusion (for those with hypotension) or controlled hyperventilation by endotracheal intubation with FIO~ of 1.0 (for those with hypoxemia or hypercarbia). These factors were considered to be present if they persisted for 30 minutes or more in the intensive care unit or ED, despite the above measures. Patients were subdivided into two groups: those with isolated head injury (IHI) and those with head injury plus multiple trauma (HI + MT). IHI patients had neurologic injury, but either minor trauma or no trauma (AIS grade 2 or less injury) to additional body areas. Patients with HI + MT had either AIS grade 3 or greater severity of injury to at least one additional body area, or AIS grade 2 injuries to two additional areas. All patients with serious head injuries were treated by protocol management, including ICP monitor in patients with GCS scores of 5 or less; ICP monitor for patients with GCS scores of 6 or 7 and an abnormal CT scan; endotracheal intubation with controlled hyperventilation (PCO2, 25 to 28 torr) and control of intracranial pressure to less than 20 tort with controlled ventilation, diuretic therapy and, when necessary, barbiturate therapy. 14:12 December 1985
MISS scores of 25 or more. TABLE 2. Severity of injury in 200 patients with GCS <~ 8
Outcome Primary Injury
Mass lesions OVR Fixed pupils
No. IHI(%)
No. HI + MT(%)
Total(%)
32(37) 33(38) 32(37)
20(17.5) 23(20.2) 34(29)
52(26) 56(28) 66(33)
Secondary Injury
ICP > 20 torr 62(72) * Systemic complications 9(10) t MISS /> 25 -* Presence of hypotension, hypoxia, or hypercarbia. tModified Injury Severity Scale score.
96(84) 49(43) 91(79.8)
158(79) 58(29) 91(45.5)
TABLE 3. Mortality among 200 patients with severe head injury
Ove rail With systemic complications Without systemic complications MISS /> 25 MISS < 25 *P < .01.
No. IHI(%) 9(10.5) 2(22) 7(78) ---
Outcome was classified according to t h e G l a s g o w O u t c o m e Scale (COS). 22 Data were subjected to chi square analysis. RESULTS During the four-year study period, 200 patients with severe head injury were treated at Primary Children's Medical Center. Age ranged f r o m three weeks to 16 years (mean, 5.6 years}. More than half of the patients were of preschool age. There were no significant differences between the mean age of patients with IHI and those with HI + MT. There were 124 boys (62%) and 76 girls (38%}. Motor vehicle and automobile pedestrian accidents accounted for more than 90% of all injuries. Two patients had spinal cord injury; none had major bums.
Severity of Injury In the total study group, 26% of patients had mass lesions, 28% had altered oculovestibular reflexes, and 33% had bilaterally fixed, dilated pupils. Among all patients undergoing ICP monitoring (N= 179), 79% had ICP of more than 20 torr. Hypotension, hypoxia, or hypercarbia were present in 29% of patients; MISS 14:12 Decem ber 1985
No. HI + MT(%) 34 (30) 30(88)
Total(%) 43 (21.5) 32(55)*
4(12) 34(37) 0
11 (7.7) 34(37)* 0
scores of 25 or more were present in 46% of patients. I H I Versus HI + NIT Eighty-six patients (43%) had IHI, and 114 patients (57%) had HI + MT. The overall severity of injury in these two groups of patients, including categorization of severity by primary head injury (mass lesions, altered OVR, fixed pupils) versus secondary head injury (increased ICP, presence of hypotension, hypoxia, or hypercarbia, and presence of additional systemic injury) is shown (Tables 1 and 2). Mass lesions, altered OVR, and presence of fixed, dilated pupils were more common in patients with IHI (P < .01). Elevated ICP was slightly more common in patients with HI + MT (84%) compared with those with IHI (72%), but this difference was not statistically significant. Of the total of 58 patients with hypotension, hypoxia, or hypercarbia, only nine had isolated head injury; 49 had HI + MT. Thus there was a 10% incidence of hypotension, hypoxia, or hypercarbia among the patients with IHI, compared w i t h 43% in those with HI + MT. Among patients with HI + MT, 91 of 114 patients (80%)had Annals of Emergency Medicine
Overall mortality was 21.5%, and only 1.5% of patients had a vegetative level of survival (Table 3}. Death, however, was nearly three t i m e s m o r e common in patients with HI + MT (30%) compared to those with IHI (10.5%). In the IHI group, two of nine patients who died (22%) had hypotension, hypoxia, or hypercarbia. Both patients had increased ICP, a GCS score of either 3 or 4, and apnea. Thirty of 34 patients (88%) with HI & MT who died had hypotension, hypoxia, or hypercarbia. Eleven of these patients had one of these elements, 15 had two, and four had all three. Of the seven IHI patients who died and did n o t h a v e h y p o t e n s i o n , hypoxia, or hypercarbia, six of seven had fixed dilated pupils, five of seven had apnea, six of seven had altered OVR, and all had GCS scores of either 3 or 4. Of the four patients with HI + MT who died and did not have hypotension, hypoxia, or hypercarbia, two of four had increased ICP and all had akered OVRs, fixed dilated pupils, and apnea. Overall there were 58 patients (29%) with hypotension, hypoxia, or hypercarbia. Mortality among patients with any of these three factors was 55%, compared with 7.7% in those without (P < .01). Among patients with MISS scores less than 25, there were no deaths compared to 34 deaths among the 91 patients with MISS scores of 25 or more (37%). The following data correlated significantly with outcome (P < .01}: GCS score of 4 or less; increased intracranial pressure; presence of hypotension, hypoxia, or hypercarbia; presence of mul.tiple trauma; and MISS score of 25 or more. The presence of surgical mass lesions did not correlate with mortality (P > .05). Ninety-five percent of surviving patients more than 5 years old are att e n d i n g t h e a p p r o p r i a t e grade in school. DISCUSSION Our primary purpose in undertaking this study was to further clarify the nature of severe neurological injury in children, as well as to clarify differences between adult and pediatric patients with severe neurological injury. Although data on outcome following head injury have been reported for 1180/79
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many years, the widespread adoption of the GCS (to describe overall level of consciousness) and the COS (to describe long-term effects of the injuries) have made head injury research vastly more intelligible by allowing contrasts and c o m p a r i s o n s b e t w e e n s t u d i e s from different centers. Prior to the use of such scales, it was difficult to assess whether outcome differences were due to differences in patient groups, severity of injury, or outcome itself. For purposes of head injury clinical research, severe head injury has been defined according to the criteria of the IDB, as described by Jennett and Teasdale. 7 These criteria consist of coma of more than six hours duration with inability to open the eyes, utter recognizable words, or follow c o m m a n d s for more than six hours - - a definition that corresponds precisely to a GCS score of 8 or less. In order to allow more intelligent comparison of our data with those from other studies, we have followed the IDB criteria. Because of the difficulty of classifying verbal response in children in the preverbal age group, we have classified any child less than 3 years old who cries to have a full verbal score. In studying our patients, we sought to answer several specific questions. First, what is the overall outcome in pediatric patients with severe head injury? Second, which specific factors are associated with outcome in these patients? Third, what is the role of multiple trauma in pediatric patients with severe head injury? Fourth, what is the role of the primary versus the secondary head injury in such pediatric patients? And finally, what implications do these data have for physicians caring for head-injured children?
Overall Outcome Previous reports of large series of head-injured patients Indicated a mortahty of 30% to 35% among pediatric p a t i e n t s (19 years old or younger) fulfilling the IDB criteria.7,9, ~3 Because adult head injury series showed outcomes of 30% to 50% in similar patients, this suggested less difference in o u t c o m e b e t w e e n pediatric and adult patients than generally had been supposed. Studies by Bruce and coworkersU, 12 and Mayer and Walker, t3,17 however, indicated that mort a l i t i e s of 6% to 10% c o u l d be achieved in IDB-compatible pediatric patients, confirming the concept that 80/1181
mortality following severe head injury can be significantly better in children than in adults. Our study group of 200 pediatric patients supports this concept inasmuch as overall mortality was 21.5%, and only 10.5% of children with isolated head injury died. Further, only three patients had a vegetative level of survival and 77% made a good recovery. More than 95% of patients more than 5 years old in this series have returned to the appropriate grade in school. C o m b i n i n g the o u t c o m e data f r o m this study with those of Bruce and coworkers]t, 12 indicates t h a t 10% to 20% mortality should be expected in pediatric patients with GCS scores of 8 or less following severe head injury..
Factors Associated with Outcome N u m e r o u s studies have sought to detail the specific factors associated with outcome from severe head injury. A m o n g the factors studied previously are level of consciousness (as assessed by the GCS),7-13,21,24 type of i n t r a c r a n i a l lesion,10, Is d u r a t i o n of c o m a , lO,18,25,z6 C T f i n d i n g s , lO,18,27 multimodality-evoked potentials,12,14,2s, 26 and intracranial hypertension.8,9, H-14 Researchers have used analysis of such factors to quantify injury severity as associated with outcome in order to further define the epidemiology of trauma, provide accurate information on prognosis, assess efficacy of e m e r g e n c y medical systems and, most importantly, facilitate c o m p a r i s o n of t h e r a p y in different groups of patients. In our study the following factors were associated with outcome: GCS score of 4 or less; presence of intracranial hypertension; presence of multiple trauma; presence of hypotension, hypoxia, or hypercarbia; and MISS score of 25 or more. (We did not assess statistically the value of multimodality-evoked potentials or computerized tomographic findings in predicting outcome.) Two other factors, altered oculovestibular reflexes and presence of bilateral fixed, dilated pupils, were associated with outcome (P < .05, and > .01). These data confirm those from previous adult studies that indicate that predictions of outcome in head-injured patients are improved significantly if additional neurologic i n f o r m a t i o n is used in conjunction with the GCS.21, 24-27 It is important to note that the presence of a surgical mass lesion did not Annals of Emergency Medicine
TABLE 4. Types of intracranial mass lesions* Type of Lesion Subdural Epidural Intracerebral Mixed lesions
No. 18 16 12 6
*Defined by CT scan or at craniotomy.
correlate with outcome in our series. Surgical mass lesions were present in 52 patients (26%), a finding that is consistent with most large series of pediatric patients.3,4,11-13 As stated previously, surgical mass lesions are seen less frequently in children than in adults. The types of mass lesions seen in our series are shown (Table 4). One reason for the lack of association between mass lesions and o u t c o m e may be the relative infrequency of the presence of acute subdural h e m a t o mas (ASDH). Only 18 patients (9%) in our series had ASDH, and six of these survived. This contrasts with the multicenter study of 1,100 adult patients in which ASDH accounted for 43.5% of all mortality2O
Multiple Trauma Studies indicate that 50% of adults with severe multiple trauma have associated head injury; 80% of multiply injured children have associated head Injury.a, 13,19,2s Multiple trauma clearly was associated with outcome in this series because m o r t a l i t y was n e a r l y t h r e e times as high in patients with multiple trauma as compared with those with isolated head injury (30% versus 10.5%; P < .011. The presence of a MISS score of 25 or more also was associated w i t h o u t c o m e . A m o n g patients with multiple trauma, 91 of 114 patients (80%) had MISS scores of 25 or more, indicating severe multiple injury. Nonetheless, m o r t a l i t y in this group still was only 37%, and the mean MISS for death was 41.5. H o w does multiple t r a u m a affect outcome in severe head injury? We believe that the major impact on outcome from multiple trauma is associated with hypotension, hypoxia, and hypercarbia, produced by the additional injuries. Overall, 29% of patients had at least one of these factors. Forty-three percent of multiple trau14:12 December 1985
TABLE 5. O u t c o m e from severe head i n j u r y in five reports* Mayer & Walker (1985)
Bruce (1978)
Bruce (1979)
No. cases
200
53
85
IHI HI + MT
43 57
74 26
77 23
26 79 28 32 5.6 y
23 80 30 34 7.2
19 73 32 33 7.1 y
Bowers & Marshall (1980)
(1978)
Miller
200
100
71 29
43 57
28 ---27 y
40 ---30 y
Percentages
Mass lesions ICP > 20 torr Altered OVR Fixed pupils Age Death/vegetative Mechanism of injury MVA/pedestrian Falls Child abuse
22.5
10
12.5
40
34
91 3 6
76 17 7
74 15 11
70 13
70 17
--
--
*GCS ~< 8; duration > 6 hr.
ma patients had at least one factor, however, compared with only i0% of patients with IHI. More importantly, 32 of 58 patients (55%) with hypotension, hypoxia, or hypercarbia died, compared with 11 deaths in 142 patients without these factors (7.7%; P < .01). These data suggest that it is not the presence of multiple trauma per se that is associated with outcome, but rather the presence of multiple trauma significant enough to produce systemic complications. Numerous studies of head-injured patients in both adult and pediatric age groups have documented that these factors significandy affect the development of intracranial hypertension and cerebral ischemia, both of which have a negative impact on outcome.8,9,11, 23-26 Additional factors that were not studied in this series but which could have a similar effect on outcome include the presence of systemic acidosis and the development of sepsis. In our series there were only three deaths from either sepsis or delayed complications of additional injuries, suggesting that these factors are less important than in multiple-injury adult patients, in whom deaths from sepsis and systemic complications are common. 28 The significance of multiple trauma in head injury has been addressed by two previous stUdies in adult patients. Miller and associates a9 examined the 14:12December 198,5
contribution of multiple trauma to mortality in a series of 100 patients with GCS scores of 10 or less and an average age of 30 (Table 5). They found that 57% of patients had significant multiple trauma and 44% had systemic complications (defined as hypotension, hypercarbia, or anemia). The presence of systemic complications was associated almost exclusively with mukiple trauma in their series. Bowers and Marshall 8 studied outcome in 200 consecutive patients with GCS scores less than 8 and an average age of 27. They found that multiple trauma requiring chest or abdominal surgery was present in 29% of patients, and that there was a statistically significant difference in outcome among patients with multiple trauma (50% mortality) compared with those with head injury alone (30% mortality). Bruce and coworkers indicated in two reports that 23% to 26% of their pediatric patients with severe head injury had associated multiple trauma.n, 12 They defined multiple trauma as long bone fractures or a ruptured abdominal organ. This contrasts sharply with our study, in which 57% of all severely head-injured children had associated severe multiple trauma. Inasmuch as isolated long bone fractures can be classified as AIS-80 grade 2 injuries (which would not per se qualify as multiple trauma in our Annals of
Emergency
Medicine
study), it is possible that their patients had an even lower incidence of multiple trauma when classified according to our system. The significant increase in associated multiple trauma in our series probably is due to differences in the mechanism of injury.. More than 90% of our patients were involved in either motor vehicle accidents or auto-pedestrian collisions, compared to 70% to 78% of patients in the Bruce, n, 12 Miller, 2s and BowersS studies. Thus the increased frequency of associated injury in our patients probably is due to higher energy transfer associated with the type of injuries our patients suffered. While the overall level of severity of head injury in the Bruce studiesn, 12 and our studies are similar with regard to mass lesions, oculovestibular reflexes, fixed, dilated pupils, and GCS scores, the markedly higher incidence of patients with multiple trauma in our series probably accounts for a great deal of the difference in mortality between the two study groups. Subsequent studies that accurately compare the incidence of multiple trauma and the development of subsequent systemic complications should help clarify this issue.
Role of Primary and Secondary Injury Currently there are limited means 1182/81
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of effectively treating primary impact injury to the brain. T h e m a j o r i t y of neurosurgicai therapy is aimed at preventing the d e v e l o p m e n t of the secondary head injury, manifested as intracranial h y p e r t e n s i o n and cerebral ischemia. Because children have a decreased incidence of mass lesions, an increased incidence of elevated intracranial pressure, and m o r e f r e q u e n t association of head injury w i t h multiple t r a u m a and subsequent hypotension, h y p o x i a , and h y p e r c a r b i a , t h e s e c o n d a r y head i n j u r y is e x t r e m e l y i m p o r t a n t to o u t c o m e in c h i l d r e n . Some children clearly die as a result of t h e i r p r i m a r y i m p a c t injury, w h i c h produces immediate, deep coma (GCS < 5) that often is resistant to intensive therapy.3,11-13, 21 N o n e t h e l e s s , even w i t h such severe primary impact injuries, our data indicate that m o r e than 70% of all children w i t h GCS scores of 3 or 4 m a k e a good recovery (normal or m o d e r a t e disability). For this reason, aggressive therapy should be offered to all children w i t h severe head injury. Our study suggests that the majority of deaths following severe head injury in children also are due to an extremely severe initial impact injury or the development of a severe secondary injury. For example; all the deaths in our series had GCS scores of 3 or 4; GCS scores of 5 or 6 with significant intracranial h y p e r t e n s i o n (ICP > 50 torr); or GCS scores of 5 or 6 and the presence of hypotension, hypoxia, or hypercarbia. Deaths from sepsis or delayed systemic complications were infrequent.
Implications for Initial Therapy Data from our series have several significant implications for physicians caring for pediatric head-injured patients. Because o p e r a t i v e n e u r o s u r g i c a ! i n t e r v e n t i o n is n e e d e d l e s s c o m m o n l y in children, t h e r e l a t i v e i m p o r t a n c e of early, intensive neurosurgical care for prevention of the secondary head injury assumes increased i m p o r t a n c e for pediatric patients. In this sense, the physician responsible for initial treatment and stabilization probably is as important to outcome in pediatric patients w i t h severe head injury as is the neurosurgeon. Emphasis should be placed on early delivery of measures designed to limit the neurological damage to that produced during the impact injury and to set the stage for repair in both neuro82/1183
logical and s y s t e m i c systems at the earliest possible time. Provision of an airway, c o n t r o l l e d h y p e r v e n t i l a t i o n (PaCO 2 of 25 to 28 torr), maintenance of an adequate blood pressure, control of intracranial pressure, and early diagnosis of the type of lesion producing coma are essential to optimal patient salvage. P r e h o s p i t a l care p r o v i d e r s s h o u l d be i n s t r u c t e d in t h e importance of measures to decrease the secondary injury, as well as the need for prompt transport. Close and ongoing cooperation between the emergency physician, pedia t r i c i a n , n e u r o s u r g e o n , and s u r g e o n will be necessary to assure appropriate o u t c o m e for pediatric p a t i e n t s w i t h severe head injury. SUMMARY Although severe neurologic injury is c o m m o n in pediatric t r a u m a victims, the m o r t a l i t y in this series of 200 patients was low (21.5%). The majority of deaths were associated either with extremely severe initial impact injury (GCS < 5) or w i t h the development of secondary injury (increased ICP, severe m u l t i p l e trauma, or the presence of hypotension, hypoxia, or hypercarbia). Early therapy to prevent secondary injury can have a significant effect on outcome in these patients.
REFERENCES 1. Wegman WE: Annual summary of vital s t a t i s t i c s - 1981. Pediatrics 1982;75: 835-843. 2. McCormick MC, Shapiro S, Storfield BH: Injury and its correlation among 1-year-old children. A m J Dis Child 1981;135:159-163. 3. Mayer T, Walker ML, Johnson DG, et ah Causes of morbidity and mortality in severe pediatric trauma. JAMA 1981;245: 719-721. 4. Velcek FT, Weiss A, Di Maio D, et al: Traumatic deaths in urban children. J Pediatr Surg 1977;12:375-384. 5. McKoy C, Bell MJ: Preventable traumatic deaths in children. J Pediatr Surg 1983;18:505-508. 6, Eichelberger MR, Randolph JG: Thoracic trauma in children. Surg Clin North Am 1981;61:1181-1i97. 7. Jennett B, Teasdale G, Galbraith S, et ah Severe head injuries in three countries. J Neurol Neurosurg Psychiatry 1977;40: 291-298. 8. Bowers SA, Marshall LF: Outcome in 200 consecutive cases of severe head injury treated in San Diego County: A proAnnals of Emergency Medicine
spective analysis. Neurosurgery 1980;6: 237-242. 9. Becker DP, Miller JD, Ward JD, et al: The outcome from severe head injury with early diagnosis and intensive management. J Neurosurg 1977;47:491-502. 10. Gennarelli TA, Spielman GM, Langfitt TW, et ah Influence of the type of intracranial lesion on outcome from severe head injury. J Neurosurg 1982;56:26-32. 11. Brace DA, Schut L, Bruno LA, et al: Outcome following severe head injuries in children. J Neurosurg 1978;48:679-688. 12. Bruce DA, Raphaely RC, Goldberg AI, et ah Path0physiology, treatment and outcome following severe head injury in children. Childs Brain 1979;5:174-191, 13. Walker ML, Storrs B, Mayer T: Factors affecting outcome in the pediatric patient with multiple trauma. Conc Pediatr Neurosurg 1983;4:243-252. 14. Seelig JM, Becker DP, Miller JD, et ah Traumatic acute subdural hematoma: Major mortality reduction in comatose patients treated within 4 hours. N EngI J Med 1981;304:1517-1518. 15. Grossman RG: Treatment of patients with intracranial hematomas. N Engl J Med 1981;304:1540-1541. 16. Strich 8J: Diffuse degeneration of the cerebral white matter in severe dementia following head injury. J Neurol Neurosurg Psychiatry 1956; 19:163-185. 17. Mayer T, Walker ML: Emergency intracranial pressure monitoring: Management of the acute coma of brain insult. Clin Pediatr (Phila) 1982;21:391-396. 18. Langfitt TW, Gennarelli TA: Can the outcome from head injury be improved? J Neurosurg 1982;56:19-25. i9. Mayer T, Matlak ME, Johnson DG, et al: The modified injury severity scale in pediatric multiple trauma patients. J Pediatr Surg 1980;15:719-726. 20. Committee on Injury Scaling: The Abbreviated Injury Scale. 1980 Revision. Morton Grove, Illinois, American Association of Automotive Medicine, 1980. 21. Mayer T, Walker ML, Clark P: Further experience with the Modified Abbreviated Injury Severity Scale. J Trauma 1984;24: 31-34. 22. Jennett B, Bond M: Assessment of outcome after severe brain damage. A practical scale. Lancet 1975;1:480-484. 23. Carlsson CA, Von Esson A, Lofgren J: Factors affecting the clinical course of patients with severe head injury. J Neurosurg 1968;29:242-251. 24. Young B, Rapp RP, Norton JA, et al: Early prediction of outcome in headinjured patients. J Neurosurg 1981;54: 300-303. 14:12 December 1985
25. Stablein DM, Miller JD, Choi SC, et al: Statistical methods for determining prognosis in severe head injury. Neurosurgery 1980;6:243-247. 26. Narayan RK, Greenberg RP, Miller JD, et al: Improved confidence of outcome
14:12 Decernber 1985
prediction in severe head injury. J Neurosurg 1981;54:751-762. 27. Van Dongen KJ, Braakman R, Gelpke GJ: The prognostic value of computerized tomography in comatose head-injured patients. J Neurosurg 1983;59:951-957.
Annals of Emergency Medicine
28. Baker CC, Oppenheimer L, Stephens B, et al: Epidemiology of trauma deaths. A m J Surg 1980;140:144-150. 29. Miller JD, Sweet Re, Narayan R, et al: Early insults to the injured brain. JAMA 1978;240:439-442.
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Pediatric Head Injury: The Critical Role of the Emergency Physician Neurologic injury is a significant source of morbidity and mortality in pediatric patients. In order to clarify the factors influencing outcome in pediatric patients with severe head injury, we studied 200 consecutive patients with Glasgow Coma Scale (GCS) scores of 8 or less. The following data were collected: age, GCS score, presence of mass lesions, oculovestibular reflexes (OVR), pupillary size and reactivity, intracranial pressure (ICP), apnea, presence of hypotension, hypoxia (PO 2 < 60 torr), or hypercarbia (PCO 2 ~ 35 torr), presence of multiple trauma, and Modified Injury Severity Scale (MISS) score. Outcome was assessed by the Glasgow Outcome Scale at a m i n i m u m of six months following recovery. Of the 200 patients in the study, 86 (43%) had isolated head injury (IHI) and 114 (57%) had head injury plus multiple trauma (HI + MT). Overall, 26% of patients had mass lesions; 28% had altered OVR; 33% had fixed, dilated pupils; 79% had increased intracranial pressure; and 29% had hypotension, hypoxia, or hypercarbia. Overall mortality was 21.5%. Severity of injury (as judged by presence of mass lesions, GCS, OVR, fixed pupils) was more pronounced in patients with 1141, although increased ICP was more common in patients with HI + MT; however, death was almost three times more common in patients with HI + M T (30% versus 10.5%). In the IHI group, two of nine patients who died (22%) had hypotension, hypoxia, or hypercarbia; all but four patients (88%) in the HI + M T group had hypotension, hypoxia, or hypercarbia. GCS of 4 or less, increased ICP, MISS score less than 25, and presence of hypotension, hypoxia, or hypercarbia correlated significantly with outcome (P < .0I). Mass lesions did not correlate with outcome. These data indicate that overall mortality from severe head injury in pediatric patients is relatively low (21.5%). The majority of deaths, however, were associated either with extremely severe initial injury or with increased intracrania] pressure, severe multiple trauma, or presence of hypotension, hypoxia, or hypercarbia. Thus although the primary impact injury dictates outcome for some pediatric patients, m a n y patients die of the secondary injury. Early therapy aimed at preventing the secondary injury can have a significant effect on outcome. In this sense, the emergency physician m a y be as important in determining outcome as is the neurosurgeon. [Mayer TA, Walker ML: Pediatric head injury: The critical role of the emergency physician. Ann Emerg Med December 1985;14:1178-1184.]
Thorn A Mayer, MD* Fort Lauderdale, Florida Marion L Walker, MDt Salt Lake City, Utah From the Department of Emergency Medicine, North Broward Hospital District, and Coastal Emergency Services, Fort Lauderdale, Florida;* and the Department of Pediatric Neurosurgery, Primary Children's Medical Center, Salt Lake City, Utah.t Received for publication May 29, 1984. Revision received July 12, 1985. Accepted for publication July 25, 1985. Presented at the University Association for Emergency Medicine Annual Meeting in Louisville, Kentucky, May 1984. Address for reprints: Thom A Mayer, MD, 2200 West Commercial Boulevard, Suite 203, Fort Lauderdale, Florida 33309.
INTRODUCTION For physicians caring for pediatric patients, it is impossible to overstate the importance of head trauma. Trauma is the number one killer of children between the ages of 1 and 14, accounting for more than 50% of all deaths, and is the third leading cause of death for children less than one year old. 2 Neurologic injury is present in almost 80% of children with trauma, and is a major cause of morbidity and mortality.3 In all reported series of trauma deaths in Children, head injury has been a major factor affecting outcome.g-6 Despite the grim toll that head injury exacts among children, studies during the past several years in both adult and pediatric patients have clarified numerous areas in the field of head injury. Among these, three are particularly important. First, the mortality from severe head injury is decreasing. A 1977 report of a multicenter, international head injury study of patients treat14:12 December 1985
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PEDIATRIC HEAD INJURY Mayer & Walker
ed from 1968 to 1974 indicated that the mortality rate for severe head injury in adults ranged from 49% to 52% among four participating centers. 7 More recent studies of similar patients have indicated mortalities of 36% to 41% 8-1o in adults and 10% to 20% mortality in children.n-14 This apparent improvement in o u t c o m e among severely head-injured patients is due to a number of factors, including increasing accessibility of definitive neurosurgical care, better prehospital care of head-injured patients, advances in monitoring and control of intracranial pressure (ICP), and early, appropriate diagnosis and therapy of both head injuries and associated injuries. Second, as diagnosis and therapy of severe head injury have improved, the concept of primary versus secondary brain injury has increased in importance. 15 Primary brain injury occurs at the time of initial impact and may involve, to varying degrees, axonal stretching and shearing (producing classical Strich lesions 16 in the brain), brain laceration, contusion, and vascular damage that will resuk in later hematoma formation. The secondary injury occurs after the initial impact injury and involves both the brain's response and the systemic response to trauma. The brain's response is a dynamic process involving loss of cerebral autoregulation, development of both extracellular and intracellular brain edema, breakdown of the blood brain barrier and, in some cases, coalescence of intracranial hemorrhage. The systemic response to trauma is largely cardiovascular and pulmonary in nature. Hypertension, hypotension, hypoxia, hypercarbia, and diminished cardiac output all may be present and further increase brain damage. Lastly, significant differences exist between adult and pediatric patients with severe head injury. Children have a much lower incidence of intracranial mass lesions following head trauma. In adult series, 40% to 50% of all patients have significant mass lesions, s-lo versus only 30% in children. 11-12 Conversely, intracranial hypertension is much more common in children than in adults. Only 40% to 50% of adult patients suffer significantly elevated ICP (ICP > 20 torr) following head injury; 80% of children have elevated ICE 17 Recent mortality in adult patients with severe head injuries ranges from 36% to 78/1179
41%, versus 10% to 20% mortality in children with similar injuries. 8qa With these facts in mind, we prospectively studied 200 pediatric patients with severe head injury in order to further clarify factors associated with outcome in pediatric patients, as well as differences between adult head injury studies and those in children.
METHODS During a four-year period (January 1978 through December 1981), 200 children who fulfilled the International Data Bank (if)B) criteriaT, 18 for severe head injury were treated at Prim a r y C h i l d r e n ' s Medical Center. These criteria were unconsciousness for more than six hours with inability to obey commands, utter recognizable words, or open the eyes, which corresponds to Glasgow Coma Scale (GCS) scores of 8 or less. Because of difficulty in applying the GCS verbal score in the preverbal age group, any child less than three years old who cried was given a m a x i m u m verbal score. Patients with a lucid interval were included only if they were unconscious for more than six hours following the lucid interval. Patients who were delayed in reaching our institution were included only if unconsciousness at our trauma center exceeded six hours. Each patient was classified prospectively according to age, sex, mechanism of injury, and severity of injury. The severity of head injury was assessed by using the GCS, pupillary light reflexes, altered oculovestibular reflexes (OVR}, presence of elevated intracranial pressure (ICP > 20 torr), or the presence of a surgical mass lesion. All surgical mass lesions were defined either at operation or by computed tomographic (CT) scan as a focal lesion causing midline shift of more than 5mm, resulting in surgical treatment. Focal edematous masses or intracerebral h e m a t o m a s were not considered surgical masses if the ICP was normal or was controlled easily. Severity of s y s t e m i c injury was judged by the Modified Injury Severity Scale (MISS) score. 19 This scale, which has been described previously, uses the Abbreviated Injury Scale-1980 classification (AIS-80} 2o except for head injuries. The MISS grades for head injury use the GCS score plus the presence of surgical mass lesions, pupillary response, and altered OVR for classification.19,21 Additional factors assessed in the Annals of Emergency Medicine
TABLE 1. Severe head injury: Overall data Category t i l l + MT
% 43 57
Mass lesions $ OVR Pupils
26 28 33
§ ICP > 20 tort Systemic complications
79 29
* IHI
Mortality 21.5 * Isolated head injury. t Head injury associated with multiple trauma. *Abnormal oculovestibular reflexes. Intracranial pressure.
overall severity of injury included the presence of hypotension (blood pressure ~< 80 + [2 x age in years]; hypoxemia (PO2 < 60 torr); or hypercarbia (PCO 2 i> 35 torr). Each of these criteria was based on ED determinations. All patients with any of these factors were managed aggressively with isotonic fluid and blood infusion (for those with hypotension) or controlled hyperventilation by endotracheal intubation with FIO~ of 1.0 (for those with hypoxemia or hypercarbia). These factors were considered to be present if they persisted for 30 minutes or more in the intensive care unit or ED, despite the above measures. Patients were subdivided into two groups: those with isolated head injury (IHI) and those with head injury plus multiple trauma (HI + MT). IHI patients had neurologic injury, but either minor trauma or no trauma (AIS grade 2 or less injury) to additional body areas. Patients with HI + MT had either AIS grade 3 or greater severity of injury to at least one additional body area, or AIS grade 2 injuries to two additional areas. All patients with serious head injuries were treated by protocol management, including ICP monitor in patients with GCS scores of 5 or less; ICP monitor for patients with GCS scores of 6 or 7 and an abnormal CT scan; endotracheal intubation with controlled hyperventilation (PCO2, 25 to 28 torr) and control of intracranial pressure to less than 20 tort with controlled ventilation, diuretic therapy and, when necessary, barbiturate therapy. 14:12 December 1985
MISS scores of 25 or more. TABLE 2. Severity of injury in 200 patients with GCS <~ 8
Outcome Primary Injury
Mass lesions OVR Fixed pupils
No. IHI(%)
No. HI + MT(%)
Total(%)
32(37) 33(38) 32(37)
20(17.5) 23(20.2) 34(29)
52(26) 56(28) 66(33)
Secondary Injury
ICP > 20 torr 62(72) * Systemic complications 9(10) t MISS /> 25 -* Presence of hypotension, hypoxia, or hypercarbia. tModified Injury Severity Scale score.
96(84) 49(43) 91(79.8)
158(79) 58(29) 91(45.5)
TABLE 3. Mortality among 200 patients with severe head injury
Ove rail With systemic complications Without systemic complications MISS /> 25 MISS < 25 *P < .01.
No. IHI(%) 9(10.5) 2(22) 7(78) ---
Outcome was classified according to t h e G l a s g o w O u t c o m e Scale (COS). 22 Data were subjected to chi square analysis. RESULTS During the four-year study period, 200 patients with severe head injury were treated at Primary Children's Medical Center. Age ranged f r o m three weeks to 16 years (mean, 5.6 years}. More than half of the patients were of preschool age. There were no significant differences between the mean age of patients with IHI and those with HI + MT. There were 124 boys (62%) and 76 girls (38%}. Motor vehicle and automobile pedestrian accidents accounted for more than 90% of all injuries. Two patients had spinal cord injury; none had major bums.
Severity of Injury In the total study group, 26% of patients had mass lesions, 28% had altered oculovestibular reflexes, and 33% had bilaterally fixed, dilated pupils. Among all patients undergoing ICP monitoring (N= 179), 79% had ICP of more than 20 torr. Hypotension, hypoxia, or hypercarbia were present in 29% of patients; MISS 14:12 Decem ber 1985
No. HI + MT(%) 34 (30) 30(88)
Total(%) 43 (21.5) 32(55)*
4(12) 34(37) 0
11 (7.7) 34(37)* 0
scores of 25 or more were present in 46% of patients. I H I Versus HI + NIT Eighty-six patients (43%) had IHI, and 114 patients (57%) had HI + MT. The overall severity of injury in these two groups of patients, including categorization of severity by primary head injury (mass lesions, altered OVR, fixed pupils) versus secondary head injury (increased ICP, presence of hypotension, hypoxia, or hypercarbia, and presence of additional systemic injury) is shown (Tables 1 and 2). Mass lesions, altered OVR, and presence of fixed, dilated pupils were more common in patients with IHI (P < .01). Elevated ICP was slightly more common in patients with HI + MT (84%) compared with those with IHI (72%), but this difference was not statistically significant. Of the total of 58 patients with hypotension, hypoxia, or hypercarbia, only nine had isolated head injury; 49 had HI + MT. Thus there was a 10% incidence of hypotension, hypoxia, or hypercarbia among the patients with IHI, compared w i t h 43% in those with HI + MT. Among patients with HI + MT, 91 of 114 patients (80%)had Annals of Emergency Medicine
Overall mortality was 21.5%, and only 1.5% of patients had a vegetative level of survival (Table 3}. Death, however, was nearly three t i m e s m o r e common in patients with HI + MT (30%) compared to those with IHI (10.5%). In the IHI group, two of nine patients who died (22%) had hypotension, hypoxia, or hypercarbia. Both patients had increased ICP, a GCS score of either 3 or 4, and apnea. Thirty of 34 patients (88%) with HI & MT who died had hypotension, hypoxia, or hypercarbia. Eleven of these patients had one of these elements, 15 had two, and four had all three. Of the seven IHI patients who died and did n o t h a v e h y p o t e n s i o n , hypoxia, or hypercarbia, six of seven had fixed dilated pupils, five of seven had apnea, six of seven had altered OVR, and all had GCS scores of either 3 or 4. Of the four patients with HI + MT who died and did not have hypotension, hypoxia, or hypercarbia, two of four had increased ICP and all had akered OVRs, fixed dilated pupils, and apnea. Overall there were 58 patients (29%) with hypotension, hypoxia, or hypercarbia. Mortality among patients with any of these three factors was 55%, compared with 7.7% in those without (P < .01). Among patients with MISS scores less than 25, there were no deaths compared to 34 deaths among the 91 patients with MISS scores of 25 or more (37%). The following data correlated significantly with outcome (P < .01}: GCS score of 4 or less; increased intracranial pressure; presence of hypotension, hypoxia, or hypercarbia; presence of mul.tiple trauma; and MISS score of 25 or more. The presence of surgical mass lesions did not correlate with mortality (P > .05). Ninety-five percent of surviving patients more than 5 years old are att e n d i n g t h e a p p r o p r i a t e grade in school. DISCUSSION Our primary purpose in undertaking this study was to further clarify the nature of severe neurological injury in children, as well as to clarify differences between adult and pediatric patients with severe neurological injury. Although data on outcome following head injury have been reported for 1180/79
PEDIATRIC HEAD INJURY Mayer & Walker
many years, the widespread adoption of the GCS (to describe overall level of consciousness) and the COS (to describe long-term effects of the injuries) have made head injury research vastly more intelligible by allowing contrasts and c o m p a r i s o n s b e t w e e n s t u d i e s from different centers. Prior to the use of such scales, it was difficult to assess whether outcome differences were due to differences in patient groups, severity of injury, or outcome itself. For purposes of head injury clinical research, severe head injury has been defined according to the criteria of the IDB, as described by Jennett and Teasdale. 7 These criteria consist of coma of more than six hours duration with inability to open the eyes, utter recognizable words, or follow c o m m a n d s for more than six hours - - a definition that corresponds precisely to a GCS score of 8 or less. In order to allow more intelligent comparison of our data with those from other studies, we have followed the IDB criteria. Because of the difficulty of classifying verbal response in children in the preverbal age group, we have classified any child less than 3 years old who cries to have a full verbal score. In studying our patients, we sought to answer several specific questions. First, what is the overall outcome in pediatric patients with severe head injury? Second, which specific factors are associated with outcome in these patients? Third, what is the role of multiple trauma in pediatric patients with severe head injury? Fourth, what is the role of the primary versus the secondary head injury in such pediatric patients? And finally, what implications do these data have for physicians caring for head-injured children?
Overall Outcome Previous reports of large series of head-injured patients Indicated a mortahty of 30% to 35% among pediatric p a t i e n t s (19 years old or younger) fulfilling the IDB criteria.7,9, ~3 Because adult head injury series showed outcomes of 30% to 50% in similar patients, this suggested less difference in o u t c o m e b e t w e e n pediatric and adult patients than generally had been supposed. Studies by Bruce and coworkersU, 12 and Mayer and Walker, t3,17 however, indicated that mort a l i t i e s of 6% to 10% c o u l d be achieved in IDB-compatible pediatric patients, confirming the concept that 80/1181
mortality following severe head injury can be significantly better in children than in adults. Our study group of 200 pediatric patients supports this concept inasmuch as overall mortality was 21.5%, and only 10.5% of children with isolated head injury died. Further, only three patients had a vegetative level of survival and 77% made a good recovery. More than 95% of patients more than 5 years old in this series have returned to the appropriate grade in school. C o m b i n i n g the o u t c o m e data f r o m this study with those of Bruce and coworkers]t, 12 indicates t h a t 10% to 20% mortality should be expected in pediatric patients with GCS scores of 8 or less following severe head injury..
Factors Associated with Outcome N u m e r o u s studies have sought to detail the specific factors associated with outcome from severe head injury. A m o n g the factors studied previously are level of consciousness (as assessed by the GCS),7-13,21,24 type of i n t r a c r a n i a l lesion,10, Is d u r a t i o n of c o m a , lO,18,25,z6 C T f i n d i n g s , lO,18,27 multimodality-evoked potentials,12,14,2s, 26 and intracranial hypertension.8,9, H-14 Researchers have used analysis of such factors to quantify injury severity as associated with outcome in order to further define the epidemiology of trauma, provide accurate information on prognosis, assess efficacy of e m e r g e n c y medical systems and, most importantly, facilitate c o m p a r i s o n of t h e r a p y in different groups of patients. In our study the following factors were associated with outcome: GCS score of 4 or less; presence of intracranial hypertension; presence of multiple trauma; presence of hypotension, hypoxia, or hypercarbia; and MISS score of 25 or more. (We did not assess statistically the value of multimodality-evoked potentials or computerized tomographic findings in predicting outcome.) Two other factors, altered oculovestibular reflexes and presence of bilateral fixed, dilated pupils, were associated with outcome (P < .05, and > .01). These data confirm those from previous adult studies that indicate that predictions of outcome in head-injured patients are improved significantly if additional neurologic i n f o r m a t i o n is used in conjunction with the GCS.21, 24-27 It is important to note that the presence of a surgical mass lesion did not Annals of Emergency Medicine
TABLE 4. Types of intracranial mass lesions* Type of Lesion Subdural Epidural Intracerebral Mixed lesions
No. 18 16 12 6
*Defined by CT scan or at craniotomy.
correlate with outcome in our series. Surgical mass lesions were present in 52 patients (26%), a finding that is consistent with most large series of pediatric patients.3,4,11-13 As stated previously, surgical mass lesions are seen less frequently in children than in adults. The types of mass lesions seen in our series are shown (Table 4). One reason for the lack of association between mass lesions and o u t c o m e may be the relative infrequency of the presence of acute subdural h e m a t o mas (ASDH). Only 18 patients (9%) in our series had ASDH, and six of these survived. This contrasts with the multicenter study of 1,100 adult patients in which ASDH accounted for 43.5% of all mortality2O
Multiple Trauma Studies indicate that 50% of adults with severe multiple trauma have associated head injury; 80% of multiply injured children have associated head Injury.a, 13,19,2s Multiple trauma clearly was associated with outcome in this series because m o r t a l i t y was n e a r l y t h r e e times as high in patients with multiple trauma as compared with those with isolated head injury (30% versus 10.5%; P < .011. The presence of a MISS score of 25 or more also was associated w i t h o u t c o m e . A m o n g patients with multiple trauma, 91 of 114 patients (80%) had MISS scores of 25 or more, indicating severe multiple injury. Nonetheless, m o r t a l i t y in this group still was only 37%, and the mean MISS for death was 41.5. H o w does multiple t r a u m a affect outcome in severe head injury? We believe that the major impact on outcome from multiple trauma is associated with hypotension, hypoxia, and hypercarbia, produced by the additional injuries. Overall, 29% of patients had at least one of these factors. Forty-three percent of multiple trau14:12 December 1985
TABLE 5. O u t c o m e from severe head i n j u r y in five reports* Mayer & Walker (1985)
Bruce (1978)
Bruce (1979)
No. cases
200
53
85
IHI HI + MT
43 57
74 26
77 23
26 79 28 32 5.6 y
23 80 30 34 7.2
19 73 32 33 7.1 y
Bowers & Marshall (1980)
(1978)
Miller
200
100
71 29
43 57
28 ---27 y
40 ---30 y
Percentages
Mass lesions ICP > 20 torr Altered OVR Fixed pupils Age Death/vegetative Mechanism of injury MVA/pedestrian Falls Child abuse
22.5
10
12.5
40
34
91 3 6
76 17 7
74 15 11
70 13
70 17
--
--
*GCS ~< 8; duration > 6 hr.
ma patients had at least one factor, however, compared with only i0% of patients with IHI. More importantly, 32 of 58 patients (55%) with hypotension, hypoxia, or hypercarbia died, compared with 11 deaths in 142 patients without these factors (7.7%; P < .01). These data suggest that it is not the presence of multiple trauma per se that is associated with outcome, but rather the presence of multiple trauma significant enough to produce systemic complications. Numerous studies of head-injured patients in both adult and pediatric age groups have documented that these factors significandy affect the development of intracranial hypertension and cerebral ischemia, both of which have a negative impact on outcome.8,9,11, 23-26 Additional factors that were not studied in this series but which could have a similar effect on outcome include the presence of systemic acidosis and the development of sepsis. In our series there were only three deaths from either sepsis or delayed complications of additional injuries, suggesting that these factors are less important than in multiple-injury adult patients, in whom deaths from sepsis and systemic complications are common. 28 The significance of multiple trauma in head injury has been addressed by two previous stUdies in adult patients. Miller and associates a9 examined the 14:12December 198,5
contribution of multiple trauma to mortality in a series of 100 patients with GCS scores of 10 or less and an average age of 30 (Table 5). They found that 57% of patients had significant multiple trauma and 44% had systemic complications (defined as hypotension, hypercarbia, or anemia). The presence of systemic complications was associated almost exclusively with mukiple trauma in their series. Bowers and Marshall 8 studied outcome in 200 consecutive patients with GCS scores less than 8 and an average age of 27. They found that multiple trauma requiring chest or abdominal surgery was present in 29% of patients, and that there was a statistically significant difference in outcome among patients with multiple trauma (50% mortality) compared with those with head injury alone (30% mortality). Bruce and coworkers indicated in two reports that 23% to 26% of their pediatric patients with severe head injury had associated multiple trauma.n, 12 They defined multiple trauma as long bone fractures or a ruptured abdominal organ. This contrasts sharply with our study, in which 57% of all severely head-injured children had associated severe multiple trauma. Inasmuch as isolated long bone fractures can be classified as AIS-80 grade 2 injuries (which would not per se qualify as multiple trauma in our Annals of
Emergency
Medicine
study), it is possible that their patients had an even lower incidence of multiple trauma when classified according to our system. The significant increase in associated multiple trauma in our series probably is due to differences in the mechanism of injury.. More than 90% of our patients were involved in either motor vehicle accidents or auto-pedestrian collisions, compared to 70% to 78% of patients in the Bruce, n, 12 Miller, 2s and BowersS studies. Thus the increased frequency of associated injury in our patients probably is due to higher energy transfer associated with the type of injuries our patients suffered. While the overall level of severity of head injury in the Bruce studiesn, 12 and our studies are similar with regard to mass lesions, oculovestibular reflexes, fixed, dilated pupils, and GCS scores, the markedly higher incidence of patients with multiple trauma in our series probably accounts for a great deal of the difference in mortality between the two study groups. Subsequent studies that accurately compare the incidence of multiple trauma and the development of subsequent systemic complications should help clarify this issue.
Role of Primary and Secondary Injury Currently there are limited means 1182/81
PEDIATRIC HEAD INJURY Mayer & Walker
of effectively treating primary impact injury to the brain. T h e m a j o r i t y of neurosurgicai therapy is aimed at preventing the d e v e l o p m e n t of the secondary head injury, manifested as intracranial h y p e r t e n s i o n and cerebral ischemia. Because children have a decreased incidence of mass lesions, an increased incidence of elevated intracranial pressure, and m o r e f r e q u e n t association of head injury w i t h multiple t r a u m a and subsequent hypotension, h y p o x i a , and h y p e r c a r b i a , t h e s e c o n d a r y head i n j u r y is e x t r e m e l y i m p o r t a n t to o u t c o m e in c h i l d r e n . Some children clearly die as a result of t h e i r p r i m a r y i m p a c t injury, w h i c h produces immediate, deep coma (GCS < 5) that often is resistant to intensive therapy.3,11-13, 21 N o n e t h e l e s s , even w i t h such severe primary impact injuries, our data indicate that m o r e than 70% of all children w i t h GCS scores of 3 or 4 m a k e a good recovery (normal or m o d e r a t e disability). For this reason, aggressive therapy should be offered to all children w i t h severe head injury. Our study suggests that the majority of deaths following severe head injury in children also are due to an extremely severe initial impact injury or the development of a severe secondary injury. For example; all the deaths in our series had GCS scores of 3 or 4; GCS scores of 5 or 6 with significant intracranial h y p e r t e n s i o n (ICP > 50 torr); or GCS scores of 5 or 6 and the presence of hypotension, hypoxia, or hypercarbia. Deaths from sepsis or delayed systemic complications were infrequent.
Implications for Initial Therapy Data from our series have several significant implications for physicians caring for pediatric head-injured patients. Because o p e r a t i v e n e u r o s u r g i c a ! i n t e r v e n t i o n is n e e d e d l e s s c o m m o n l y in children, t h e r e l a t i v e i m p o r t a n c e of early, intensive neurosurgical care for prevention of the secondary head injury assumes increased i m p o r t a n c e for pediatric patients. In this sense, the physician responsible for initial treatment and stabilization probably is as important to outcome in pediatric patients w i t h severe head injury as is the neurosurgeon. Emphasis should be placed on early delivery of measures designed to limit the neurological damage to that produced during the impact injury and to set the stage for repair in both neuro82/1183
logical and s y s t e m i c systems at the earliest possible time. Provision of an airway, c o n t r o l l e d h y p e r v e n t i l a t i o n (PaCO 2 of 25 to 28 torr), maintenance of an adequate blood pressure, control of intracranial pressure, and early diagnosis of the type of lesion producing coma are essential to optimal patient salvage. P r e h o s p i t a l care p r o v i d e r s s h o u l d be i n s t r u c t e d in t h e importance of measures to decrease the secondary injury, as well as the need for prompt transport. Close and ongoing cooperation between the emergency physician, pedia t r i c i a n , n e u r o s u r g e o n , and s u r g e o n will be necessary to assure appropriate o u t c o m e for pediatric p a t i e n t s w i t h severe head injury. SUMMARY Although severe neurologic injury is c o m m o n in pediatric t r a u m a victims, the m o r t a l i t y in this series of 200 patients was low (21.5%). The majority of deaths were associated either with extremely severe initial impact injury (GCS < 5) or w i t h the development of secondary injury (increased ICP, severe m u l t i p l e trauma, or the presence of hypotension, hypoxia, or hypercarbia). Early therapy to prevent secondary injury can have a significant effect on outcome in these patients.
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