Aortic dissection

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The Journal

0 CHILDHOOD FEVER: CORRELATION OF DIAGNOSIS WITH TEMPERATURE RESPONSE TO ACETAMINOPHEN. Baker MD, Fosarelli PD, Carpenter RO.

Pediatrics. 1987; 80:315-319. It is commonly believed that the temperature response to acetaminophen varies according to diagnosis. This hypothesis was prospectively studied in febrile patients who presented to an urban pediatric emergency and walk-in facility. The study group consisted of 1,559 patients between the ages of 8 weeks and 6 years whose rectal temperatures on arrival were greater than 38.4 “C and who had not received antipyretic therapy within the previous four hours. Patients received 15 mgikg of acetaminophen and temperatures were recorded at one and two hours. The recorded decrease in temperature was slightly greater among children who had positive cultures or radiographically documented pneumonia; although this difference was statistically significant, it was not great enough to be clinically useful. Thus, no etiologic inference can be made on the basis of the temperature response to acetaminophen. [Daniel A. Zak, MD] Editor’s Note: This study will be welcomed by emergency physicians who must deal with parents and nurses who demand a child be normothermic before discharge, although I doubt it will convince them.

0 EXPOSURE EMERGENCY PERFORMED

To IONIZING RADIATION IN THE DEPARTMENT FROM COMMONLY PORTABLE RADIOGRAPHS. Grazer

RE, Meislin HW, Westerman BR, et al. Ann Emerg Med. 1987; 16:417-420. To assessthe potential hazard of exposure to ionizing radiation from portable radiographs in the emergency department, this study measured radiation at different distances from the edge of an irradiated field during portable cervical spine, chest, and pelvis radiographs. The radiation levels were highest for pelvic films and decreased dramatically with distance. At 40 cm (15 inches) from the beam for a chest or cervical spine film, and at 160 cm (60 inches) for a pelvic film, radiation exposure was minimal. At these distances, one would need to be exposed to more than 1,200 such radiographs to equal background radiation. Medical personnel should not have to leave a patient care area for fear of undue acute and chronic radiation exposure during portable radiographic examinations. [Alan F. Chou, MD] Editor’s Note: This is very useful information. In the confused, struggling patient, it is helpful to hold the desired position during the exposure of the portable film. We would still recommend wearing a lead apron.

0 SELECTIVE MANAGEMENT OF BLUNT ABDOMINAL TRAUMA IN CHILDREN: THE TRIAGE ROLE OF PERITONEAL LAVAGE. Rothenberg S, Moore EE,

Marx JA, et al. J Trauma. 1987; 27:1101-l 106. This report describes the results of a protocol developed after retrospective review of emergency laparotomies in 52 children sustaining blunt abdominal trauma with positive

of Emergency

Medune

diagnostic peritoneal lavages (DPL) by traditional criteria revealed a high incidence of injuries that could have been managed nonoperatively. The protocol consisted of (1) routine DPL in children at high risk for abdominal injury; (2) laparotomy for DPL positive for blood in the face of hemodynamic instability; (3) mandatory laparotomy for DPL positive by criteria other than blood; (4) selective laparotomy for DPL positive for blood in a stable child following additional evaluation by abdominal computed tomography (CT) scan (major mechanism) or liver/spleen scan (minor mechanism). This policy reduced the number of unnecessary laparotomies to 18% (2/l 1). Five children with low-energy trauma were managed nonoperatively after liver/spleen scanning showed minor visceralinjury despite aspiration of gross blood by DPL. The authors conclude that this experience supports continued use of DPL as the initial triage point in evaluation, with CT scanning and scintigraphy providing further information for selectivemanagement. [R. Scott Israel, MD] Editor’s Note: Further evidence that children are not just miniature adults; but this article should not be expanded to a lessaggressiveapproach in the adult trauma victim.

0 POOR PREDICTION OF POSITIVE COMPUTED TOMOGRAPHIC SCANS BY CLINICAL CRITERIA IN SYMPTOMATIC PEDIATRIC HEAD TRAUMA. Rivara

F, Tanaguchi D, Parish RA, et al. Pediatrics. 1987; 80:579584. Delayed diagnosis of intracranial injury in children with head trauma can result in death or significant morbidity. This retrospective record review analyzed children with head injury who had received a computed tomography (CT) scan of the head to attempt to discover clinical signs that would accurately identify those who would have abnormal CT findings. Half the CT scans showed abnormalities; the most frequent findings were subdural hematoma (32%), linear (25%) and depressed (25%) skull fractures, and cerebral contusion (22%). Patients were more likely to have abnormal CT findings if any of the following were present: loss of consciousness greater than five minutes, Glasgow coma scale of 12 or less, unequal pupils, posturing, focal neurologic abnormalities, or hemotympanum. However, each finding had low sensitivity for predicting brain injury. The ability to predict normal CT results was also unsatisfactory. Six patients without the above findings had abnormal scan results. The authors conclude that the clinical findings studied did not adequately predict brain injury. [Douglas A. Schneider, MD] Editor’s Note: Prohibitively large studies would be needed to identify safe selection criteria for CT use in head injury.

0 AORTIC DISSECTION. DeSanctis RW, Dorghazi RM, Austen WG, et al. NEngI JMed. 1987; 317:1060-1067. Aortic dissection results from a tear in the tunica intima,

257 which allows blood to enter the media, creating a false channel. Death usually results from aortic rupture. The most common site of dissection is the ascending aorta near the aortic valve, with the next most common being the descending aorta just distal to the left subclavian. The underlying pathologic factor associated with the aortic dissection is degeneration of the media. The most common predisposing factor is hypertension; other factors are congenital disorder of connective tissue, ie, Marfan’s and Ehlers-Danlos syndromes. Clinical finding include severe chest pain, often described as tearing or ripping; neurologic signs; diminution of principal pulses; signs of aortic insufficiency; and evidence of peripheral arterial occlusion. Evidence of pericardial effusion or tamponade, if present, is a poor prognostic sign. Approximately 90% of patients will have abnormal chest X-ray findings. Emergent treatment of dissection involves control of hypertension with nitroprusside and beta blockers. Acute proximal dissections should be corrected surgically whenever possible. Acute therapy for distal dissection is controversial; medical and surgical survival rates are comparable. [Janyce M. Sanford, MD]

0 IDENTIFICATION OF LOW-RISK MONITOR ADMISSIONS TO MEDICAGSURGICAL ICUS. Wagner DP, Knaus WA, Draper EA. Chest. 1987; 92:423-428. This multicenter study of 5,790 intensive care unit (ICU) admissions attempted to identify patients who were at such low risk of receiving unique ICU therapies that their admission might have been avoided. The patients encompassed a broad range of medical and surgical diseases, excluding acute myocardial infarction, burns, and patients under 16 years of age. Therapeutic interventions were described by the Therapeutic Intervention Scoring System (TISS). After exclusion of 3,849 patients who required at least 1 of 31 TISS items during the first 24 hours of admission, a predictive equation was developed from a subset of 778 of the remaining patients to predict the risk of receiving at least one of the 31 TISS items unique to the ICU environment. The authors arbitrarily chose a 10% risk of ICU intervention as the threshold to divide “low risk” from “high risk.” This formula was then applied to the 1,941 patients who did not receiveunique ICU intervention during the first 24 hours of admission. A total of 1,358 patients (70%) were predicted to have less than a 10% risk of requiring subsequent unique ICU intervention; of these low-risk patients, only 58 (4.3%) subsequently required unique ICU treatment, compared with 108 (18.5 %) of the high-risk patients. [Francis M. Fesmire, MD] Editor’s Note: Since the validation phase of this study included patients from the estimation phase, the results are biased and overly optimistic. It should be noted that savings in ICU usage will be partially offset by the increased labor costs on the wards and by the loss of crosssubsidization of sicker patients by the lesssick.

q OUTCOME IN SUSPECTED ACUTE MYOCARDIAL INFARCTION WITH NORMAL OR MINIMALLY ABNORMAL ELECTROCARDIOGRAPHIC FINDINGS. Slater DK, Hlatky MA, Mark DB, et al. .4m J Cardiol. 1987; 60:766-770. A total of 775 consecutive patients admitted with a diagnosis of suspected acute myocardial infarction (AMI) were studied to determine clinical outcome in patients with normal or minimally abnormal initial ECG findings. Initial ECG results were classified as normal, nonspecific ST-T wave changes, or abnormal. A total of 107 study patients (14%) had normal ECG findings, 73 (9%) had nonspecific ECG findings, and 595 (77 %) had abnormal ECG findings. The rate of AMI for normal, nonspecific, and abnormal ECG findings was lo%, 8%, and 41%, respectively. The rate of life-threatening complications was 4%, 11%, and 25%, and mortality was O%, 1%, and 6%, respectively. Of the 12 patients with normal or nonspecific ECG results who had a life-threatening complication, only one patient in the normal group and four patients in the nonspecific group required specific ICU intervention. The authors conclude that the initial emergency department ECG can effectively separate patients into high- and low-risk groups and that admission of low-risk patients to an intermediate care ward may be an acceptable practice. [Francis M. Fesmire, MD] Editor’s Note: Although ECG changes can certainly be used to rank patients in order of risk, the level of risk at which less intensive therapy is justified has not been determined.

0 DIABETIC KETOACIDOSIS AND INFECTION: LEUKOCYTE COUNT AND DIFFERENTIAL AS EARLY PREDICTORS OF SERIOUS INFECTION. Slovis CM, Mork VGC, Slovis RJ, et al. Am J Emerg Med. 1987; 5:1-5. The records of 169 patients who presented to an emergency department with diabetic ketoacidosis (DKA) were reviewed to determine whether any admission evaluation laboratory data could serve as a predictor of occult or coexisting infection. Nineteen percent of the patients were excluded because of incomplete charts or clinically apparent infections on chest films or physical examination at the time of admission. of the remaining 141 patients, 11 (78 %) did not develop or have intercurrent infections that were recognized within the first 48 hours of hospitalization. Eleven (8%) developed infections not requiring antibiotics, and 19 (13 %) developed infections requiring antibiotic treatment. Of the readily available admission variables (age, sex, temperature, glucose, bicarbonate, pH, leukocyte count, and differential), only elevated bands on the differential was associated with occult infection. A band count of 10 or greater predicted major infection with 100% sensitivity (19/19, 95% confidence interval, 82% to 100%) and 80% specificity (98/122, 95 % confidence interval, 73% to 87%). [Robert Bayer, MD] Editor’s Note: Urinalysis was not performed routinely on all patients in the emergency department and thus those