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Appendicitis: Usefulness of us in diagnosis in a pediatric population
Abstracts
0 APPENDICITIS: USEFULNESS OF US IN DIAGNOSIS IN A PEDIATRIC POPULATION. Sivit C, Newman K, Boenning D. Radiology. 1992;185:549-552. This study attempts to assess the usefulness of ultrasound (US) in the diagnosis of appendicitis in children, and to compare the findings with the clinical assessments made in the diagnosis of this disorder. 180 pediatric patients with suspected appendicitis were prospectively evaluated with graded compression, real time US. Patients were assigned to one of three groups before the US based on the clinical level of confidence that appendicitis was present, and on the proposed management. In the low and intermediate clinical risk categories, 20 out of 141 patients had appendicitis (14%). US had a sensitivity of lOO%, specificity of 97%, and accuracy of 97% in these two groups. The high clinical risk category resulted in 32 out of 39 patients having appendicitis (82%). In this group, US had a sensitivity of 8 1%, specificity of 86%) and accuracy of 82%. 18 out of 52 patients with surgically proved appendicitis had an initial plan to discharge home or to admit for observation. The US results were positive for appendicitis in all 18 patients. [Floriane c. Wu, MD] Editor’s Comment: In institutions where many such studies are being performed, US is becoming a useful adjunct in both pediatric and adult age groups for the diagnosis of appendicitis.
0 A DETECTION OF ACUTE APPENDICITIS BY TECHNETIUM 99 HMPAO SCANNING. Foley CR, Latimer RG, Rimkus DS. Am Surgeon. 1992;58(12):761-765. This prospective study evaluated the use of technetium99m (Tc-99m) scanning for diagnosing acute appendicitis. The authors note that the diagnosis of acute appendicitis is a challenging one. Barium enemas, computed tomography (CT) scans, ultrasound examinations, and Indium scans have been used with varying degrees of success. In this study, 25 cc of whole blood was taken from the patient with suspected acute appendicitis. This was incubated with Tc-99m for 90 minutes to allow its absorption into white blood cells. This labeled blood was then infused into the patient. Abdominal imaging was performed at 30 minutes and 3 hours after infusion. The scans were read as negative, positive for appendicitis, or positive for another intraabdominal process. Of 27 patients, 16 had histologically proven appendicitis post-operation. Of these 16, thirteen had scans positive for appendicitis, with three false negative studies. All eleven patients without appendicitis had either negative scans or scans that detected other intraabdominal processes. The cost of the Technetium scan ($400) was found to be half that of the Indium scan, and comparable in cost to ultrasound and CT scan. The authors conclude that with an 81% sensitivity, this would be a useful test in patients without the classic signs of appendicitis. [Richard A. Oyler, MD] Editor’s Comment: This may be a useful inpatient test, but the time requirement to perform this examination
367
makes ultrasound the preferable modality to utilize from the Emergency Department.
0 THE INCREASED RISK OF ULCERATIVE KERATITIS AMONG DISPOSABLE SOFT CONTACT LENS USERS. Buehler PO, Schein OD, Stamler JF. Arch Ophthalmol. 1992;110:1555-1558. The relative risk of ulcerative keratitis in contact lens wearers based on lens type was examined in a 2.5 year case control study. Lens type was defined as: daily wear soft contact lens, rigid gas permeable contact lens, extendedwear soft contact lens, and disposable contact lens. Fortytwo cosmetic contact lens wearers diagnosed with ulcerative keratitis, and were matched to control groups based on dispensing practitioner and date of dispensing. Risk was assessed by odds ratios (OR) for each lens type, and adjusted for age and gender using the daily wear soft lens as the standard. Results suggested the lowest risk of ulcerative keratitis exists among rigid gas permeable lens users. Disposable lens posed the greatest risk with an OR fourteen fold greater than daily wear. Data were consistent with those displayed in two prior case control studies. [Teresa Mazur, MD] Editor’s Comment: This small study did not take into account different lens hygiene practices or patterns of lens wear.
Cl ORAL KETAMINE PREMEDICATION TO ALLEVIATE THE DISTRESS OF INVASIVE PROCEDURES IN PEDIATRIC ONCOLOGY PATIENTS. Tobias JD, Phipps S, Smith B, Mulhern RK. Pediatrics. 1992;90(4): 537-541. This study prospectively followed thirty-five pediatric oncology patients undergoing invasive procedures such as lumbar puncture and bone marrow aspiration. Children ranged in age from 14 months to 17 years. The level of sedation was evaluated using the Observational Scale of Behavioral Distress. Parental and clinician scores were obtained using the Likert scale. Ketamine hydrochloride intravenous solution was given orally in a dose of lOmg/kg mixed in a beverage of the child’s choice. All children were given nothing orally (NPO) for six hours prior to ketamine ingestion. At thirty minutes postingestion, 77% were adequately sedated and 87% were sedated adequately at 45 minutes. Post-procedure recovery time prior to clinic discharge was 2-4 hours. There were no complications of respiratory depression, and 91% of patients exhibited no sign of the emergence phenomenon associated with ketamine. Although there was no control group in this study, the authors extrapolated a control group from a previous study at their institution comparing intravenous saline and intravenous midazolam for invasive procedures. By doing so, they concluded that oral ketamine is a more effective sedative for pediatric procedures than either saline or intravenous midazolam. [Suzanne Chilton, MD]
0 APPENDICITIS: USEFULNESS OF US IN DIAGNOSIS IN A PEDIATRIC POPULATION. Sivit C, Newman K, Boenning D. Radiology. 1992;185:549-552. This study attempts to assess the usefulness of ultrasound (US) in the diagnosis of appendicitis in children, and to compare the findings with the clinical assessments made in the diagnosis of this disorder. 180 pediatric patients with suspected appendicitis were prospectively evaluated with graded compression, real time US. Patients were assigned to one of three groups before the US based on the clinical level of confidence that appendicitis was present, and on the proposed management. In the low and intermediate clinical risk categories, 20 out of 141 patients had appendicitis (14%). US had a sensitivity of lOO%, specificity of 97%, and accuracy of 97% in these two groups. The high clinical risk category resulted in 32 out of 39 patients having appendicitis (82%). In this group, US had a sensitivity of 8 1%, specificity of 86%) and accuracy of 82%. 18 out of 52 patients with surgically proved appendicitis had an initial plan to discharge home or to admit for observation. The US results were positive for appendicitis in all 18 patients. [Floriane c. Wu, MD] Editor’s Comment: In institutions where many such studies are being performed, US is becoming a useful adjunct in both pediatric and adult age groups for the diagnosis of appendicitis.
0 A DETECTION OF ACUTE APPENDICITIS BY TECHNETIUM 99 HMPAO SCANNING. Foley CR, Latimer RG, Rimkus DS. Am Surgeon. 1992;58(12):761-765. This prospective study evaluated the use of technetium99m (Tc-99m) scanning for diagnosing acute appendicitis. The authors note that the diagnosis of acute appendicitis is a challenging one. Barium enemas, computed tomography (CT) scans, ultrasound examinations, and Indium scans have been used with varying degrees of success. In this study, 25 cc of whole blood was taken from the patient with suspected acute appendicitis. This was incubated with Tc-99m for 90 minutes to allow its absorption into white blood cells. This labeled blood was then infused into the patient. Abdominal imaging was performed at 30 minutes and 3 hours after infusion. The scans were read as negative, positive for appendicitis, or positive for another intraabdominal process. Of 27 patients, 16 had histologically proven appendicitis post-operation. Of these 16, thirteen had scans positive for appendicitis, with three false negative studies. All eleven patients without appendicitis had either negative scans or scans that detected other intraabdominal processes. The cost of the Technetium scan ($400) was found to be half that of the Indium scan, and comparable in cost to ultrasound and CT scan. The authors conclude that with an 81% sensitivity, this would be a useful test in patients without the classic signs of appendicitis. [Richard A. Oyler, MD] Editor’s Comment: This may be a useful inpatient test, but the time requirement to perform this examination
367
makes ultrasound the preferable modality to utilize from the Emergency Department.
0 THE INCREASED RISK OF ULCERATIVE KERATITIS AMONG DISPOSABLE SOFT CONTACT LENS USERS. Buehler PO, Schein OD, Stamler JF. Arch Ophthalmol. 1992;110:1555-1558. The relative risk of ulcerative keratitis in contact lens wearers based on lens type was examined in a 2.5 year case control study. Lens type was defined as: daily wear soft contact lens, rigid gas permeable contact lens, extendedwear soft contact lens, and disposable contact lens. Fortytwo cosmetic contact lens wearers diagnosed with ulcerative keratitis, and were matched to control groups based on dispensing practitioner and date of dispensing. Risk was assessed by odds ratios (OR) for each lens type, and adjusted for age and gender using the daily wear soft lens as the standard. Results suggested the lowest risk of ulcerative keratitis exists among rigid gas permeable lens users. Disposable lens posed the greatest risk with an OR fourteen fold greater than daily wear. Data were consistent with those displayed in two prior case control studies. [Teresa Mazur, MD] Editor’s Comment: This small study did not take into account different lens hygiene practices or patterns of lens wear.
Cl ORAL KETAMINE PREMEDICATION TO ALLEVIATE THE DISTRESS OF INVASIVE PROCEDURES IN PEDIATRIC ONCOLOGY PATIENTS. Tobias JD, Phipps S, Smith B, Mulhern RK. Pediatrics. 1992;90(4): 537-541. This study prospectively followed thirty-five pediatric oncology patients undergoing invasive procedures such as lumbar puncture and bone marrow aspiration. Children ranged in age from 14 months to 17 years. The level of sedation was evaluated using the Observational Scale of Behavioral Distress. Parental and clinician scores were obtained using the Likert scale. Ketamine hydrochloride intravenous solution was given orally in a dose of lOmg/kg mixed in a beverage of the child’s choice. All children were given nothing orally (NPO) for six hours prior to ketamine ingestion. At thirty minutes postingestion, 77% were adequately sedated and 87% were sedated adequately at 45 minutes. Post-procedure recovery time prior to clinic discharge was 2-4 hours. There were no complications of respiratory depression, and 91% of patients exhibited no sign of the emergence phenomenon associated with ketamine. Although there was no control group in this study, the authors extrapolated a control group from a previous study at their institution comparing intravenous saline and intravenous midazolam for invasive procedures. By doing so, they concluded that oral ketamine is a more effective sedative for pediatric procedures than either saline or intravenous midazolam. [Suzanne Chilton, MD]