- Email: [email protected]
The course of transient ischemic attacks
87
Abstracts
compared to the physicians. The authors conclude that decision protocols based on the analysis of large data sets can outperform physicians’ unaided judgment. They also caution that the protocol should never override common sense but may be a helpful adjunct for physicians in certain situations . [Jeff Cox, MD] Editor’s Note: It should be noted that this study did not specifically address the emergency physician’s dilemma of whether to admit or discharge, but rather concentrated on secondary triage of patients, once admitted, to higher and lower levelsof care.
0 IMPROVING THE FIELD TRIAGE OF MAJOR TRAUMA VICTIMS. Knudson P, Frecceri CA, Delateur
SA. J Trauma. 1988;28:602-6. The goal of field triage in a regionalized trauma system is to correctly identify seriously injured patients for transport to a designated trauma center. The Champion Trauma Score, CRAMS scale, and mechanism of injury were evaluated as predictors of significant injury in this retrospective analysis of 500 patients brought to an urban community hospital which was the closest facility. The criteria used to identify 206 patients (41%) as significantly injured were Injury Severity Score (ISS)> 15, emergency room Trauma Score< 15, injuries resulting in > 3 days hospitalization, or death. Adding mechanism of injury to either the Trauma Score or CRAMS scale enhanced sensitivity at the expense of specificity. The sensitivity of a CRAMS scales 8 increased from 66% to 93 % while specificity fell from 82 % to 30%; similarly, the sensitivity of a trauma scores 14 increased from 45 % to 75 %, with a drop in specificity of 94% to 40%. By combining mechanism of injury with the standard triage systems, sensitivity is enhanced, improving the problem of under-triage, but at the expense of increasing the amount of overtriage. [William Dietrich, MD] Editor’s Note: The probability of severeinjury noted in this study was 41% , indicating that substantial selection of patients occurred prior to the investigation. The problem of the tradeoff between sensitivity and specificity is even more acute if a more realistic probability of severe injury (say 10%) is used. Triaging 1000 trauma patients (100 severely injured) using mechanism plus Trauma Score< 15 instead of Trauma Score alone would result in 516 additional patients being sent to a trauma center, of whom 30 would be severely injured (marginal probability 5.8%); 25 severely injured patients would still be missed.
96 patients with ISS> 25 treated with ALS in the prehospital setting. The patients were similar in both groups with regard to ISS, age, and proportion of blunt trauma. Significant differences were found in time of treatment at the accident scene(BLS 17 minutes v ALS 13 minutes), number of deaths within 24 hours of the trauma (24 of 33 BLS and 17 of 37 ALS deaths), and the rate of respiratory failure (19% of BLS and 5% of ALS cases). Despite the higher incidence of respiratory failure in the BLS cases, no other significant differences in morbidity or overall mortality were noted. The authors note that much larger studies (500 patients per group) would be needed to ensure a 90% probability of finding an absolute difference of 10% in mortality between ALS and BLS treatment groups. [Dwight Peake, MD] Editor’s Note: The definition of severe injury in this study was rather restrictive (ISS greater than 15 is more commonly used as the dividing line). It is possible that the benefits, if any, of ALS are restricted to an as yet unspecified range of ISS scoresand could be hidden if diluted with patients who are unsalvageable under any circumstances.
0 PEDIATRIC ABDOMINAL TRAUMA: TION BY COMPUTED TOMOGRAPHY.
EVALUA-
Kane NM, Cronan JJ, Dorfman GS, DeLuca F. Pediatrics. 1988;82: 11-15. A retrospective study to evaluate the efficacy of computed tomography (CT) as a diagnostic aid in pediatric blunt abdominal trauma was performed. One hundred consecutive pediatric patients not requiring immediate operation underwent CT of the abdomen with contrast. Seventy-three patients had normal studies. Twenty-seven were abnormal, including nine hepatic injuries, nine splenic injuries, six renal injuries, one traumatic pancreatitis, one duodenal hematoma, and one hemoperitoneum. Three of these patients required subsequent operation while the rest were managed conservatively. None of the 73 patients with normal studies suffered any clinically recognizable abdominal morbidity. There were no mortalities due to abdominal injury in either group. The authors conclude that CT is useful in detecting and delineating the extent of injury in pediatric abdominal blunt trauma and may aid in the decision of operative v nonoperative management. [Lynda Leigh Fluskey, MD] Editor’s Note: Blunt injury in children is significantly different from that in adults; it is often a nonoperative condition. Computed tomography’s contribution appears to lie in its ability to assessthe extent of injury, rather than just to announce its presence.
0 A CONTROLLED TRIAL OF PREHOSPITAL ADVANCED LIFJ3 SUPPORT IN TRAUMA. Potter D, Gold-
stein G, Fung SC, Selig M. Ann Emerg Med. 1988;17: 582-8. This controlled prospective study examined the effect of Advanced Life Support (ALS) on the mortality and morbidity of major trauma patients. Seventy-four patients with an Injury Severity Scores (ISS)>25 with prehospital care consisting of Basic Life Support (BLS) were compared with
0 THE TACKS.
COURSE
OF TRANSIENT
ISCHEMIC
AT-
Werdelin L, Juhler M. Neurology. 1988;38:677-
80. Transient ischemic attacks (TIAs) have been differentiated from stroke by the resolution of neurological deficits within 24 hours of onset. The purpose of this prospective study was to characterize the average time course of TIAs to
88
The Journal
determine whether the diagnosis of TIA v stroke could be made earlier, and to correlate the nature and severity of symptoms at onset with short-term prognosis. The 78 patients studied had new-onset neurological disease, manifested by well described symptoms of focal diagnostic value, presumed ischemic origin, and onset within the preceding 24 hours. Neurological deficits were graded from time of symptom onset (based on history) and hospital presentation to 24 hours after onset, at which time a diagnosis of either stroke or TIA was made. Of the 20 patients who had a TIA, half had full recovery within 1 hour of symptom onset and 90% recovered within 4 hours. The severity of neurological deficit at the time of onset was significantly less for TIA patients than for stroke patients. The authors conclude that duration of symptoms beyond a few hours and severity of clinical symptoms at onset are reliable indicators of the diagnosis of TIA. [Heidi Kapanka, MD]
•i THE ALVEOLAR-ARTERIAL OXYGEN GRADIENT IN PATIENTS WITH DOCUMENTED PULMONARY EMBOLISM. Overton DT, Backs JJ. Arch Intern Med.
1988;148:1617-9. It is thought that an elevated alveolar-arterial (A-a) gradient is often present with acute pulmonary embolism. This retrospective study sought to determine if a patient with acute pulmonary embolism could present with a normal A-a gradient. In 64 patients with angiographically proven emboli, the A-a gradient (on room air) ranged from 11.6 to 83.9 with a mean of 41.8& 16.9 mm Hg. Three patients (4.8% of the study group) had a gradient that was normal for age (defined as less than 4+ageM). The authors conclude that a normal A-a gradient does not exclude the diagnosis of acute pulmonary embolism and, therefore, should not preclude further diagnostic evaluation if a high clinical probability exists. [Heidi Kapanka, MD] Editor’s Note: This study is basically an existence proof; a case report would have been sufficient. However, it is always good to reaffirm the principle that laboratory abnormalities should not be allowed to over-rule clinical observation and impression.
Cl SHOTGUN
WOUNDS
OF THE HEAD
AND
NECK.
Grimes WR, Morris DM, Deitch EA. Am J Surg. 1988; 155:776-g. This is a retrospective review of 26 patients seen for shotgun wounds to the head and neck. Over half of the patients had associated injuries to the trunk or extremities. Over 20% of patients with shotgun wounds to the head and neck had injuries of other anatomic areas that required operative repair; all the life-threatening injuries in this group were outside the head and neck region. Ocular injuries occurred in 54% and were the most morbid injury with functional vision returning in only 2 of 16 eyes. From evaluation of patients’ hemodynamic status on presentation to the ED and their anatomic pattern of injury (point-blank,
of Emergency
Medicine
close range, or long range), one could predict the need for surgery as well as the risk of death. [Dan Zak, MD] Editor’s Note: While shotgun wounds to the head and neck are quite impressive, with proper airway control, one can quickly move to the life-threatening associated injuries.
0 COMPUTED TOMOGRAPHY IN THE EVALUATION OF THE PATIENT WITH SYMPTOMATIC ABDOMINAL AORTIC ANEURYSM. Zarnke MD, Gould
HR, Goldman MH. Surgery. 1988;103:638-42. During a 2-year period, 25 hemodynamically stable patients with suspected leaking abdominal aneurysm were evaluated by emergent computed tomography (CT) of the abdomen. An abdominal aneurysm was diagnosed if any portion of the abdominal aorta was greater than 3 cm in diameter. A leaking aneurysm was identified by the presence of periaortic retroperitoneal fluid consistent with blood. Of these 25 patients, 10 were found to have leaking abdominal aortic aneurysms. Of these ten 9 were confirmed. There was one false negative study that resulted in a death, for an overall sensitivity of 90% (g/10). On CT, 12 patients were judged not to have a leaking aneurysm and 3 had no aneurysm at all. There was one false positive scan in a patient with an 8 cm aortic aneurysm that was causing a partial obstruction of the right colon and fluid in the retroperitoneal spacethat was misread as blood on the CT scan. Overall specificity was 93% (14/15). Unsuspected nonvascular problems were found in half of the patients with negative scans. These included a gluteal hematoma, peripancreatic inflammation, cholelithiasis, intestinal obstruction, and spontaneous splenic infarction. The authors recommended that if CT examination and qualified interpretation is available, CT should be used as the initial and definitive study for the diagnosis of leaking abdominal aortic aneurysm. If the CT is positive, surgical repair must follow [Jeffrey Schaider, MD] immediately. Editor’s Note: This is useful information for the stable patient. In the unstable patient, immediate surgery is a preferable course.
0 SUCCINYLCHOLINE-ASSISTED INTUBATIONS IN PREHOSPITAL CARE. Hedges JR, Dronen SC, Feero S,
et al. Ann Emerg Med. 1988;17:469-72. The authors review two years of an EMS system’sexperience with use of succinylcholine to facilitate prehospital orotracheal intubation. Trained in its use during regularly scheduled operating room sessions,the system’sparamedics have selectivelyused succinylcholine (SUX) as part of their standing orders for ten years. During the two years reviewed, 310 patient intubations were attempted with SUX used on 95 patients. Intubation attempts had a 96% success rate in both groups. The SUX group was characterized by a statistically significantly greater percentage of women, higher mean Glasgow Coma Scale score, smaller percentage of cardiac arrest victims, and greater percentage of
Abstracts
compared to the physicians. The authors conclude that decision protocols based on the analysis of large data sets can outperform physicians’ unaided judgment. They also caution that the protocol should never override common sense but may be a helpful adjunct for physicians in certain situations . [Jeff Cox, MD] Editor’s Note: It should be noted that this study did not specifically address the emergency physician’s dilemma of whether to admit or discharge, but rather concentrated on secondary triage of patients, once admitted, to higher and lower levelsof care.
0 IMPROVING THE FIELD TRIAGE OF MAJOR TRAUMA VICTIMS. Knudson P, Frecceri CA, Delateur
SA. J Trauma. 1988;28:602-6. The goal of field triage in a regionalized trauma system is to correctly identify seriously injured patients for transport to a designated trauma center. The Champion Trauma Score, CRAMS scale, and mechanism of injury were evaluated as predictors of significant injury in this retrospective analysis of 500 patients brought to an urban community hospital which was the closest facility. The criteria used to identify 206 patients (41%) as significantly injured were Injury Severity Score (ISS)> 15, emergency room Trauma Score< 15, injuries resulting in > 3 days hospitalization, or death. Adding mechanism of injury to either the Trauma Score or CRAMS scale enhanced sensitivity at the expense of specificity. The sensitivity of a CRAMS scales 8 increased from 66% to 93 % while specificity fell from 82 % to 30%; similarly, the sensitivity of a trauma scores 14 increased from 45 % to 75 %, with a drop in specificity of 94% to 40%. By combining mechanism of injury with the standard triage systems, sensitivity is enhanced, improving the problem of under-triage, but at the expense of increasing the amount of overtriage. [William Dietrich, MD] Editor’s Note: The probability of severeinjury noted in this study was 41% , indicating that substantial selection of patients occurred prior to the investigation. The problem of the tradeoff between sensitivity and specificity is even more acute if a more realistic probability of severe injury (say 10%) is used. Triaging 1000 trauma patients (100 severely injured) using mechanism plus Trauma Score< 15 instead of Trauma Score alone would result in 516 additional patients being sent to a trauma center, of whom 30 would be severely injured (marginal probability 5.8%); 25 severely injured patients would still be missed.
96 patients with ISS> 25 treated with ALS in the prehospital setting. The patients were similar in both groups with regard to ISS, age, and proportion of blunt trauma. Significant differences were found in time of treatment at the accident scene(BLS 17 minutes v ALS 13 minutes), number of deaths within 24 hours of the trauma (24 of 33 BLS and 17 of 37 ALS deaths), and the rate of respiratory failure (19% of BLS and 5% of ALS cases). Despite the higher incidence of respiratory failure in the BLS cases, no other significant differences in morbidity or overall mortality were noted. The authors note that much larger studies (500 patients per group) would be needed to ensure a 90% probability of finding an absolute difference of 10% in mortality between ALS and BLS treatment groups. [Dwight Peake, MD] Editor’s Note: The definition of severe injury in this study was rather restrictive (ISS greater than 15 is more commonly used as the dividing line). It is possible that the benefits, if any, of ALS are restricted to an as yet unspecified range of ISS scoresand could be hidden if diluted with patients who are unsalvageable under any circumstances.
0 PEDIATRIC ABDOMINAL TRAUMA: TION BY COMPUTED TOMOGRAPHY.
EVALUA-
Kane NM, Cronan JJ, Dorfman GS, DeLuca F. Pediatrics. 1988;82: 11-15. A retrospective study to evaluate the efficacy of computed tomography (CT) as a diagnostic aid in pediatric blunt abdominal trauma was performed. One hundred consecutive pediatric patients not requiring immediate operation underwent CT of the abdomen with contrast. Seventy-three patients had normal studies. Twenty-seven were abnormal, including nine hepatic injuries, nine splenic injuries, six renal injuries, one traumatic pancreatitis, one duodenal hematoma, and one hemoperitoneum. Three of these patients required subsequent operation while the rest were managed conservatively. None of the 73 patients with normal studies suffered any clinically recognizable abdominal morbidity. There were no mortalities due to abdominal injury in either group. The authors conclude that CT is useful in detecting and delineating the extent of injury in pediatric abdominal blunt trauma and may aid in the decision of operative v nonoperative management. [Lynda Leigh Fluskey, MD] Editor’s Note: Blunt injury in children is significantly different from that in adults; it is often a nonoperative condition. Computed tomography’s contribution appears to lie in its ability to assessthe extent of injury, rather than just to announce its presence.
0 A CONTROLLED TRIAL OF PREHOSPITAL ADVANCED LIFJ3 SUPPORT IN TRAUMA. Potter D, Gold-
stein G, Fung SC, Selig M. Ann Emerg Med. 1988;17: 582-8. This controlled prospective study examined the effect of Advanced Life Support (ALS) on the mortality and morbidity of major trauma patients. Seventy-four patients with an Injury Severity Scores (ISS)>25 with prehospital care consisting of Basic Life Support (BLS) were compared with
0 THE TACKS.
COURSE
OF TRANSIENT
ISCHEMIC
AT-
Werdelin L, Juhler M. Neurology. 1988;38:677-
80. Transient ischemic attacks (TIAs) have been differentiated from stroke by the resolution of neurological deficits within 24 hours of onset. The purpose of this prospective study was to characterize the average time course of TIAs to
88
The Journal
determine whether the diagnosis of TIA v stroke could be made earlier, and to correlate the nature and severity of symptoms at onset with short-term prognosis. The 78 patients studied had new-onset neurological disease, manifested by well described symptoms of focal diagnostic value, presumed ischemic origin, and onset within the preceding 24 hours. Neurological deficits were graded from time of symptom onset (based on history) and hospital presentation to 24 hours after onset, at which time a diagnosis of either stroke or TIA was made. Of the 20 patients who had a TIA, half had full recovery within 1 hour of symptom onset and 90% recovered within 4 hours. The severity of neurological deficit at the time of onset was significantly less for TIA patients than for stroke patients. The authors conclude that duration of symptoms beyond a few hours and severity of clinical symptoms at onset are reliable indicators of the diagnosis of TIA. [Heidi Kapanka, MD]
•i THE ALVEOLAR-ARTERIAL OXYGEN GRADIENT IN PATIENTS WITH DOCUMENTED PULMONARY EMBOLISM. Overton DT, Backs JJ. Arch Intern Med.
1988;148:1617-9. It is thought that an elevated alveolar-arterial (A-a) gradient is often present with acute pulmonary embolism. This retrospective study sought to determine if a patient with acute pulmonary embolism could present with a normal A-a gradient. In 64 patients with angiographically proven emboli, the A-a gradient (on room air) ranged from 11.6 to 83.9 with a mean of 41.8& 16.9 mm Hg. Three patients (4.8% of the study group) had a gradient that was normal for age (defined as less than 4+ageM). The authors conclude that a normal A-a gradient does not exclude the diagnosis of acute pulmonary embolism and, therefore, should not preclude further diagnostic evaluation if a high clinical probability exists. [Heidi Kapanka, MD] Editor’s Note: This study is basically an existence proof; a case report would have been sufficient. However, it is always good to reaffirm the principle that laboratory abnormalities should not be allowed to over-rule clinical observation and impression.
Cl SHOTGUN
WOUNDS
OF THE HEAD
AND
NECK.
Grimes WR, Morris DM, Deitch EA. Am J Surg. 1988; 155:776-g. This is a retrospective review of 26 patients seen for shotgun wounds to the head and neck. Over half of the patients had associated injuries to the trunk or extremities. Over 20% of patients with shotgun wounds to the head and neck had injuries of other anatomic areas that required operative repair; all the life-threatening injuries in this group were outside the head and neck region. Ocular injuries occurred in 54% and were the most morbid injury with functional vision returning in only 2 of 16 eyes. From evaluation of patients’ hemodynamic status on presentation to the ED and their anatomic pattern of injury (point-blank,
of Emergency
Medicine
close range, or long range), one could predict the need for surgery as well as the risk of death. [Dan Zak, MD] Editor’s Note: While shotgun wounds to the head and neck are quite impressive, with proper airway control, one can quickly move to the life-threatening associated injuries.
0 COMPUTED TOMOGRAPHY IN THE EVALUATION OF THE PATIENT WITH SYMPTOMATIC ABDOMINAL AORTIC ANEURYSM. Zarnke MD, Gould
HR, Goldman MH. Surgery. 1988;103:638-42. During a 2-year period, 25 hemodynamically stable patients with suspected leaking abdominal aneurysm were evaluated by emergent computed tomography (CT) of the abdomen. An abdominal aneurysm was diagnosed if any portion of the abdominal aorta was greater than 3 cm in diameter. A leaking aneurysm was identified by the presence of periaortic retroperitoneal fluid consistent with blood. Of these 25 patients, 10 were found to have leaking abdominal aortic aneurysms. Of these ten 9 were confirmed. There was one false negative study that resulted in a death, for an overall sensitivity of 90% (g/10). On CT, 12 patients were judged not to have a leaking aneurysm and 3 had no aneurysm at all. There was one false positive scan in a patient with an 8 cm aortic aneurysm that was causing a partial obstruction of the right colon and fluid in the retroperitoneal spacethat was misread as blood on the CT scan. Overall specificity was 93% (14/15). Unsuspected nonvascular problems were found in half of the patients with negative scans. These included a gluteal hematoma, peripancreatic inflammation, cholelithiasis, intestinal obstruction, and spontaneous splenic infarction. The authors recommended that if CT examination and qualified interpretation is available, CT should be used as the initial and definitive study for the diagnosis of leaking abdominal aortic aneurysm. If the CT is positive, surgical repair must follow [Jeffrey Schaider, MD] immediately. Editor’s Note: This is useful information for the stable patient. In the unstable patient, immediate surgery is a preferable course.
0 SUCCINYLCHOLINE-ASSISTED INTUBATIONS IN PREHOSPITAL CARE. Hedges JR, Dronen SC, Feero S,
et al. Ann Emerg Med. 1988;17:469-72. The authors review two years of an EMS system’sexperience with use of succinylcholine to facilitate prehospital orotracheal intubation. Trained in its use during regularly scheduled operating room sessions,the system’sparamedics have selectivelyused succinylcholine (SUX) as part of their standing orders for ten years. During the two years reviewed, 310 patient intubations were attempted with SUX used on 95 patients. Intubation attempts had a 96% success rate in both groups. The SUX group was characterized by a statistically significantly greater percentage of women, higher mean Glasgow Coma Scale score, smaller percentage of cardiac arrest victims, and greater percentage of