HYPOGLYCEMIA, SCREENING; GLUCOSE, TESTING

Chemstrip glucose test strips: Correlation with true glucose values less than 80 mg/dL Maisels M J, Lee CA Crit Care Med 11:293-295 Apr 1983

Expeditious bedside estimation of the serum glucose level in the hypoglycemic patient can be fraught with technical difficulty and frequently with inaccuracy. In this study, the authors evaluated the efficacy of Chemstrip bG and StatTek Glucose Low Level test strips in determining glucose levels between the range of 0 and 80 mg/dL. Fresh blood was obtained from three adult donors. Samples were pooled and incubated for 24 hours at 37 C in order to obtain a theoret- ical blood glucose of zero. Three sets of 22 samples were randomly labeled and a glucose solution was added to create varying glucose concentrations ranging from 0 to 80 mg/dL. Chemstrip bG and StatTek strip readings were carried out by six persons, and the values were then compared to stan- dard laboratory determinations. A true positive was defined as a test strip value < 40 mg/dL and a plasma glucose value < 30 mg/dL. A false negative was defined as a test strip value of/> 40 mg/dL with a plasma glucose value < 30 mg/ dL. A false positive was defined as a test strip value < 40 mg/dL with a plasma level > 40 mg/dL. A total of 132 read- ings were made on 66 samples. For Chemstrip and StatTek there were 54 true positives and no false negatives, giving a sensitivity of 100%. Test specificity was 84% for Chemstrip and 97% for StatTek. Positive predictive value (a measure of the probability that hypoglycemia is present in a patient) with a test strip value < 40 mg/dL was 86% for Chemstrip and 96% for StatTek. The negative predictive value (a measure of how well a negative test predicts the absence of hypoglycemia) was 100% for both. Although both methods give some false positives, significant hypoglycemia will not be missed (no false negatives). The authors conclude that both Chemstrip and StatTek are excellent screening tests for hypoglycemia.

William H Blahd, Jr, MD

PARASITOSIS; PEDIATRIC, PARASITOSIS

Intestinal parasitosis in an urban pediatric clinic population FIores EC, Plumb SC, McNeese MC Am J Dis Child 137:754-758 Aug 1983

Three hundred twenty-one consecutive pediatric patients who presented to a Houston pediatric clinic were pro- spectively screened for intestinal parasites. An attempt was made to screen all patients from 6 months to 16 years of age with a single stool specimen. The number of these patients with gastrointestinal complaints was not specified. Results

revealed that 98.1% of the study population was Hispanic, with 35% reporting recent travel to Mexico. Of the 321 samples, 158 (49.5%) were positive for intestinal parasites. Giardia was the most prevalent parasite (20.6%), followed by ~ichuris and Ascaris (5% each) and Hymenolepis nana (4%). There were no significant differences between pa- tients with positive or negative samples with regard to age, sex, signs, symptoms, or number of visits to the clinic. There was a significant correlation between recent travel to Mexico and a positive stool specimen. The authors con- clude that there is a higher-than-expected incidence of asymptomatic parasitic infection in those studied. There appear to be no reliable clinical or laboratory predictors of parasitic infestations. The authors recommend routine peri- odic screening of Mexican-American children with recent travel to Mexico, regardless of clinical findings.

James McLaughlin, MD

CT SCAN, HEPATIC TRAUMA; TRAUMA, HEPATIC, CT SCAN

Computed tomography in hepatic trauma Moon KL, Federle MP A JR 141,309-314 Aug 1983

The authors describe a retrospective study of 280 patients with blunt upper abdominal trauma who were evaluated with C T examinations. Of these, 25 had preoperative CT revealing evidence of hepatic injury, eight had postoperative CT scans revealing hepatic injury (and were excluded from the study), and 247 had CT examinations that revealed no evidence of hepatic injury. Of the 247 without CT evidence of hepatic injury, 45 underwent laparotomy for other inju- ries. None of these had surgical evidence of hepatic injury. Of the remaining 202, none had a clinical course suggestive of significant hepatic injury. Of the 25 who had CT evi- dence of hepatic injury, only 10 underwent laparotomy. Seven of these had visible or palpable evidence of hepatic injury (confirming CT findings) at the time of surgery. The remaining three had CT-defined lesions in the postero- superior aspect of the right lobe of the liver, where inspec- tion or palpation was not possible.'The 15 patients with CT- defined hepatic injury who were managed without lapa- rotomy had uncomplicated hospital courses. The decision to operate was also compared with CT findings, and seemed to correlate with the size of hepatic laceration or the size of hemoperitoneum. Each of the 10 patients who underwent laparotomy had at least the following: 1) a large hepatic laceration (6/10); 2) a medium to large hemoperitoneum (6/ 10); 3) a significant extrahepatic abdominal injury (2/10); or 4) a hematoma which expanded between two examinations (1/10). The authors discuss the advantages of CT over hepat- ic scintigraphy, angiog~aphy, and diagnostic peritoneal la- vage, and suggest that it may be useful in determining which patients with blunt upper abdominal trauma can be managed nonoperatively. [Editor's note: Another study that suggests that diagnostic peritoneal lavage may soon be-

12:12 December 1983 Annals of Emergency Medicine 793/91