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Delayed Presentation after Head Injury: Is a Computed Tomography Scan Necessary? More than 2 million people a year come to medical attention as a result of head trauma in the United States.1 To date, a large number of published studies relate to the diagnosis and treatment of acute minor head trauma.2–17 The conclusions of these studies often conflict and generally do not address the approach to certain subsets of head-injured patients such as those with a minor head injury who present for evaluation after a delay. Most emergency physicians agree on the concerning signs and symptoms in the moderately or severely head-injured patient presenting acutely. However, there is less consensus on the evaluation and treatment of patients with ‘‘mild’’ injury, defined as a Glasgow Coma Score (GCS) of 13–15 with or without a history of loss of consciousness or posttraumatic amnesia.2,3 Some physicians advocate early CT evaluation for nearly all mild head injury cases,4–8 whereas others would take a more liberal approach.10–12 Recent work has begun to make it clear that clustering all patients with a GCS of 13–15 into one population may be inappropriate because a significant number of patients with scores of 13 and 14 have brain injury.2,4,5,9 This leaves those patients with a GCS of 15 and history of head injury as a potentially low-risk population. However, even here, there is debate as to the best approach and disposition.13–17 Given this controversy in the management of acute head trauma, it is difficult to know how to treat a patient with minor head trauma who presents after a delay. While some reports describe delayed head injury, there is little useful information in regard to evaluation and management.18–24 In this era of managed care, it would be helpful to determine whether a delayed presentation of at least 12 hours constitutes an adequate period of ‘‘observation,’’ or whether these patients warrant further evaluation. The objective of this study was to determine the incidence of significant injury despite having survived a period of at least 12
hours since head trauma. Additionally, specific risk factors for predicting injury were sought.
METHODS Study Design. This was a retrospective chart review performed at the EDs of two academic Level 1 trauma centers in the same city with a combined volume of approximately 85,000. As a chart review, this study was considered exempt from informed consent.
Study Setting and Population. All ED charts from January through December 1996 were reviewed for chief complaint or symptoms relating to head injury. Patients were included if the initial injury occurred at least 12 hours prior to presentation and the patient had a GCS of 15 at the time of the first ED evaluation. While an exact definition of ‘‘delayed presentation’’ does not exist, those patients with significant head injury commonly decompensate before 12 hours have passed. Therefore, patients who presented 12 hours or more after their head injuries were considered delayed for the purposes of this study. Patients evaluated by a physician immediately after head injury with a GCS of 15, but who returned later, were included even if a CT had been performed at the initial evaluation. These patients were included because neither a negative evaluation nor a negative CT scan immediately following head trauma excludes the possibility that pathology was present or may develop.24,25 The charts of patients who had received a prior ED evaluation were reviewed to ensure that the initial GCS was 15 and that the initial neurologic examination was listed as normal. Transferred patients were excluded.
Measurements. Charts were reviewed for the following data: age, time of injury, type of injury, symptoms both at time of injury and at presentation (including headache, dizziness, nausea, vomiting, vision
changes, neck pain), associated injuries (facial injury, multiple trauma), historical features (loss of consciousness, amnesia, alcohol or drug intoxication, posttraumatic seizure), and physical findings (basilar skull fracture, suspected child abuse, depressed level of consciousness, and focal neurologic findings). Additionally, any progression of the above symptoms was noted. Significant delayed injury was defined as abnormal CT results such as: intracerebral bleeding, skull fracture, or subdural or epidural hematoma. Because not all patients received a head CT during the ED visit, it is possible that small injuries were missed that may have come to attention at a later date due to evaluation by a provider outside of the ED. Patients in the military setting most commonly come back to this system for their health care. Therefore, we searched the radiographic computer and hospital admission records for all patients who did not receive a CT during the ED visit to determine whether they may have received a CT at a later date. As well, since a normal CT does not guarantee that no pathology will develop later, records were also reviewed for those patients who had a CT during an ED evaluation.
Data Analysis. The incidence of disease was determined with 95% confidence intervals (95% CIs). The populations from the two hospitals were compared using chi-square and t-test. Comparisons between patients with and without positive findings were made using multiple logistic regression.
RESULTS A total of approximately 85,000 charts were reviewed. Of these, approximately 2,900 patients with head injury as a chief complaint or discharge diagnosis were located. Of these, 194 patients met the criteria for delayed presentation. Of the 194 patients, 101 had CT scans performed at delayed presentation (index visit). The rest were discharged based on historical and clinical demonstration of a normal exam. Twenty-one (10.8%) patients had been seen at the time of their origi-
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TABLE 1. Patients with Delayed Presentation Following Head Injury Initial Symptoms‡
Physical Findings
CT Findings
None
Hematoma, left temple
Basilar skull fracture
No LOC; no symptoms
GCS§ = 3
Hematoma, left temple; coma
Initial CT(⫺); repeat CT: large subdural hematoma
MVP
HA; vomiting; hematoma; no LOC
HA; nausea; decreased LOC
Scalp hematoma
Frontal intraparenchymal hematoma
48 and 96 hours
Fall
HA
HA, worsening
Normal exam
Frontal subdural hematoma; skull fracture
60-year-old male
48 hours
Fall; history of drinking
HA; nausea; slurred speech; arm weakness
HA; dizziness; nausea
Normal exam
Subdural and epidural hematomas with frontal contusion
5-month-old female
20 hours
Hit by toy truck
Decreased appetite; no LOC
Increased sleepiness
Bruise on temporal area
Left frontal and anterior hematoma
Patient
Latency*
History†
21-month-old female
24 hours
MVC
Sleepy; lethargic
74-year-old male
25 hours
Fall
29-year-old female
23 hours
46-year-old female
Presenting Symptoms
*Latency = time to ED presentation following head injury. †MVC = motor vehicle crash; MVP = motor vehicle vs pedestrian crash. ‡LOC = loss of consciousness; HA = headache. §GCS = Glasgow Coma Scale score.
nal trauma and returned to the ED with progressive or continued complaints. Nine of the 21 patients had received a CT scan during the initial visit. There were 112 women and 82 men. The mean age was 34 years (SD ⫾ 24 years). One hundred eleven cases came from one hospital. There was no difference in the variables studied between the two institutions. Of the 194 patients, six had an abnormality noted on CT. This represents 3.1% incidence of significant head trauma after delayed presentation (95% CI = 1% to 7%). Positive CT findings included one intracerebral bleed, three subdural hematomas, one subdural and epidural hematoma, and one skull fracture. One patient with a normal CT scan 24 hours prior returned with a GCS of 3 from a large subdural hematoma, and subsequently died. He was on chronic salicylate therapy but was
not taking any other anticoagulants. This was the only patient who decompensated after a normal CT scan on initial presentation. Table 1 illustrates the pertinent findings of the patients. The mean time to presentation or representation after the initial head injury was 73 hours (⫾105) for the entire population. For those found to have pathology, the mean time to presentation was 29.3 hours (⫾10.7). Upon review of radiographic and inpatient admissions for those patients who did not receive a CT during an ED visit, 14 were found who received a CT scan at some point after their ED evaluation for symptoms that appeared to relate to their head injury. One patient received a head CT for abrupt onset of headache three months after her original ED visit. At that time she was found to have a chronic subdural hematoma, and it is likely that this injury was present at the time of her initial
ED visit. Her original ED complaint was of neck pain related to a fall. She struck her head, but had no loss of consciousness and no other specific complaint related to this and she did not receive a head CT. No medical or surgical intervention was needed for this patient. If this patient was considered to have a significant delayed injury, the incidence of disease was 3.6% (95% CI = 1% to 7%). Five of the seven patients with abnormal CT scans had no reported loss of consciousness at the time of trauma. With the exception of the woman who was found to have a subdural hematoma months later, most of the patients had concerning historical or physical features that led the physician to get a CT scan. Two of the patients were young children for whom the parents reported changes in mental status, one was a 60-year-old male with history of alcoholism and report by the family
ACADEMIC EMERGENCY MEDICINE • September 1999, Volume 6, Number 9
suggestive of focal neurologic deficit (although at the time of the evaluation his neurologic examination was normal), one patient was having increasingly severe and unusual headaches, one patient was markedly confused, and one patient presented comatose. Only the last patient, who was taken emergently to surgery, required neurosurgical intervention. Three patients were admitted for a brief period of observation but no medical or surgical therapy was needed. The two children were allowed to go home in the care of their parents with daily neurosurgical follow-up. There was no significant difference between the patients with pathology and those without; however, the numbers were small. Due to the limited number of patients with disease, predictors of pathology could not be determined.
DISCUSSION At the end of the last century, delayed posttraumatic hemorrhage was identified in four patients two weeks after initial presentation and criteria were proposed for its diagnosis.18 There have been reports since then of delayed posttraumatic intracranial hemorrhage.19,20,22,23,25,26 Snoey and Levitt described three patients who developed delayed subdural hematomas, all of whom had previously had normal CT scans.24 Other recent reports have identified cases with a significantly prolonged interval of minimal symptoms prior to deterioration from intracranial hemorrhage.5,21,22 To the best of our knowledge, only one study has addressed delayed presentation in detail. In this study patients were included if 1) they had previous evaluation by skull film and observation in the ED and 2) they returned to the ED. Seventeen percent of patients had an abnormality other than skull fracture on CT scan.25 It is difficult to know whether the 17% rate of pathology found applies to a population with delayed presentation or applies only to those who receive an initial evaluation (without a CT) and then return due to worsening symptoms. It is possible that the group who waited to be seen had milder initial trauma, which is why they did not think it was worthwhile to come
for medical evaluation immediately. This may be a very different population from the group presenting immediately after head injury, only to return again due to continued or worsening symptoms. However, both populations represent delayed presentation patients. In our study, seven of 194 patients (3.6%) with delayed presentation of head injury had significant findings on CT. Five of the seven patients had no reported loss of consciousness. Fortunately, most of the patients had some historical or physical findings that would have led most prudent physicians to get a CT scan. Only one of the group previously had a CT scan that was read as normal. He returned 23 hours later comatose and subsequently died. This patient serves to remind us that an initially negative CT is no guarantee that pathology will not develop in the future. In those patients with increasingly severe symptoms, even with a previously normal CT scan, it may be prudent to repeat a CT scan.27 One study, a case series of patients presenting to the ED more than 24 hours after suffering blunt head trauma, found an 6.3% incidence of disease.28 None of these patients required neurosurgical intervention and, unlike our study, these investigations found that a history of loss of consciousness was helpful in predicting CT abnormalities. Our study and that of Stein and Ross8 suggest an incidence of CT abnormality between 3% and 6% in patients with delayed presentation following head injury. However, the significance of some of the more minor CT findings in both studies could be questioned since only one patient in both studies needed neurosurgery. Indeed, some of the ‘‘positive’’ findings may have gone undetected in the era prior to CT scans, with little symptomatology or long-term morbidity. Certainly this raises the question of the need to use the CT scanner to find what may amount to insignificant pathology. One study, however, would suggest that up to 5% of patients with these late findings will eventually need urgent neurosurgical intervention.25 With these conflicting study results, an argument can be made that there is some merit in finding pathology in the patient with a delayed presen-
959 tation following head trauma. Patients found to have an abnormality on CT may need hospitalization to detect early mental status decline should complications develop. Yet exactly which head-injured patient with a delayed presentation should be hospitalized for observation has not been determined. At a minimum, all patients with CT abnormality should have close follow-up arranged. Another reason to diagnose pathology in these patients is that those with injury may have a delay in returning to baseline function. Identification of injury can allow appropriate counseling, time off from work, and follow-up to maximize recovery.
LIMITATIONS AND FUTURE QUESTIONS The nature of the retrospective review makes it difficult to ensure that all of the desired data points are present on each patient chart, and thus, some important data may be missing. In addition, physicians may document more details for patients in whom injury was found. Not all patients in this study received a head CT when they presented. As suggested by the single patient found to have a chronic subdural on the CT scan done months later, it is possible that other patients may have had pathology that was never detected. Since patients may harbor pathology that never necessitates intervention, it remains likely that this study underestimated the incidence of disease. The clinical significance of these findings is uncertain. We considered ‘‘significant pathology’’ to be any finding that, at our institution, would change the disposition or management of the patient. This may differ at other institutions, and between consulting neurosurgeons and emergency physicians. We believe that the potential for significant CT findings suggested by this and other studies warrants further study with greater statistical power. A prospective multicenter study may identify both the incidence and predictive criteria for significant findings in delayed-presentation head-injury patients. Further study might also determine the outcome of those patients found to have
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pathology to further determine the necessity of finding this disease.
CONCLUSIONS We found a 3.6% incidence of pathology on CT scan in patients presenting more than 12 hours after acute head injury. Most patients did not require acute surgical or medical intervention. We suggest that pathology does exist in patients presenting to the ED in a delayed fashion after head injury; however, the need for urgent medical or neurosurgical intervention is low. We recommend that clinicians approach this population cautiously until larger studies better define the clinical significance and outcomes of those patients who have pathology detected at delayed ED presentations following head trauma. — ROBIN R. HEMPHILL, MD, San Antonio Uniformed Services Health Education Consortium, Emergency Medicine Residency, Brooke Army Medical Center, San Antonio, TX, and Department of Emergency Medicine, Vanderbilt University Medical Center, Nashville, TN; SALLY A. SANTEN, MD, Department of Emergency Medicine, Vanderbilt University Medical Center, Nashville, TN; and PAUL E. KLEINSCHMIDT, MD, San Antonio Uniformed Services Health Education Consortium, Emergency Medicine Residency, Brooke Army Medical Center, San Antonio, TX
BRIEF REPORTS
of bedside clinical indicators in identifying significant intracranial injury in trauma patients. J Trauma. 1992; 32: 359–63. 5. Stein SC, Ross SE. Mild head injury: a plea for routine early CT scanning. J Trauma. 1992; 33:11–3. 6. Teasdale GM, Murray G, Anderson E, et al. Risks of acute traumatic intracranial hematoma in children and adults: implications for managing head injuries. BMJ. 1990; 300:363–7. 7. Klauber MR, Marshall LF, Luerssen TG, et al. Determinants of head injury mortality: importance of the low risk patient. Neurosurgery. 1989; 24:31–6. 8. Stein SC, Ross S. The value of computed tomographic scans in patients with low-risk head injuries. Neurosurgery. 1990; 26:638–40. 9. Madden C, Witzke DB, Sanders AB, et al. High-yield selection criteria for cranial computed tomography after acute trauma. Acad Emerg Med. 1995; 2:248– 53. 10. Masters SJ, McClean PM, Arcarese JS, et al. Skull x-ray examinations after head trauma. N Engl J Med. 1987; 316: 84–91. 11. Mohonty SK, Thompson W, Rakower S. Are CT scans for head injury patients always necessary? J Trauma. 1991; 31: 801–5. 12. Borczuk P. Predictors of intracranial injury in patients with mild head injury. Ann Emerg Med. 1995; 25:731–6. 13. Rockswald GL, Pheley PJ. Patients who talk and deteriorate. Ann Emerg Med. 1993; 22:1004–7. 14. Stein SC, Ross SE. Minor head injury: a proposed strategy for emergency management [editorial]. Ann Emerg Med. 1993; 22:1193–5. 15. Miller EC, Derlet RW, Kinser D. Minor head trauma: is computed tomography always necessary? Ann Emerg Med. 1996; 27:290–2. 16. Miller EC, Holmes JF, Derlet RW. Utilizing clinical factors to reduce head CT scan ordering for minor head trauma patients. J Emerg Med. 1997; 15:453–7.
17. Jeret JS, Mandell M, Anziska B, et al. Clinical predictors of abnormality disclosed by computed tomography after mild head trauma. Neurosurgery. 1993; 32:9–16. 18. Alvarez-Sabin J, Turon A, LozanoSanchez M, Vazquez J, Codina A. Delayed posttraumatic hemorrhage ‘‘spat apoplexie.’’ Stroke. 1995; 26:1531–5. 19. Dietch D, Kirshner HS. Subdural hematoma after normal CT. Neurology. 1989; 39:985–7. 20. Ashkenazi E, Constantini S, Pomeranz S, Rivkind AI, Rappaport ZH. Delayed epidural hematoma without neurologic deficit. J Trauma. 1990; 30:613– 5. 21. Elsner H, Rigamonti D, Corradino G, Schlegel R, Joslyn J. Delayed traumatic intracerebral hematomas: ‘‘spatapoplexie.’’ Report of two cases [comment]. J Neurosurg. 1990; 72:813–5. 22. Miller JD, Murray LS, Teasdale GM. Development of a traumatic intracranial hematoma after a ‘‘minor’’ head injury. Neurosurgery. 1990; 27:669–73. 23. Poon WS, Rehman SU, Poon CY, Li AK. Traumatic extradural hematoma of delayed onset is not a rarity. Neurosurgery. 1992; 30:681–6. 24. Snoey ER, Levitt MA. Delayed diagnosis of subdural hematoma following normal computed tomography scan. Ann Emerg Med. 1994; 23:1127–31. 25. Voss M, Knottenbelt JD, Peden MM. Patients who reattend after head injury; a high risk group. BMJ. 1995; 311:1395– 8. 26. Sainsbury CP, Sibert JR. How long do we need to observe head injuries in hospital? Arch Dis Child. 1984; 59:856– 9. 27. Di Rocco A, Ellis SJ. Delayed epidural hematoma. Neuroradiology. 1991; 33:253–4. 28. Borczuk P, Ostrander J, Dienstag J. Cranial computed tomography scans in patients presenting 24 hours after blunt head trauma [abstract]. Acad Emerg Med. 1997; 4:410.
Presented in abstract form at the ACEP Research Forum, San Francisco, CA, October 1997.
Key words. head injury; closed; delayed; brain injury; skull fracture; emergency department; computed tomography.
References 1. Collins JG. Types of injuries by selected characteristics: United States, 1985–1987. Vital Health Stat 10. 1990; Dec:1–68. 2. Shackford SR, Wald SL, Ross SE. The clinical utility of computed tomographic scanning and neurologic examination in the management of patients with minor head injuries. J Trauma. 1993; 33:385– 94. 3. Borczuk P. Mild head trauma. Emerg Med Clin North Am. 1997; 15:563–79. 4. Harad FT, Kerstein MD. Inadequacy
Iatrogenic Worsening of Hypokalemia and Neuromuscular Paralysis Associated with the Use of Glucose Solutions for Potassium Replacement in a Young Woman with Licorice Intoxication and Furosemide Abuse Chronic licorice intoxication is a well-recognized cause of hypokalemia. The active ingredient, glycyrrhizic acid, is a competitive inhibitor of the enzyme 11-hydroxysteroid dehydrogenase.1 This enzyme catalyzes the conversion of cortisol, which has considerable mineralocorticoid activity, to its inactive metabolite cortisone.2
Licorice withdrawal and potassium replacement are the mainstay of therapy, though caution is advised in the use of IV potassium and recommendations are made about the rate of infusion. It is clear that the oral administration is the safest route for potassium supplementation, since potassium enters the circulation more slowly with a reduced