Fredric Jarrett

A semiquantitative culture method for identification of catheter-related infection in the burn patient☆☆☆

Abstract A semiquantitative (SQ) method for culturing vascular catheters on solid media has been evaluated with 50 high-risk catheters from 6 patients with extensive second- and third-degree burns. The technique reliably differentiates catheter-related infection from contamination; a positive SQ culture (> 15 colonies) denotes local infection and a concentration exceeding 10 5 organisms per gram in the catheter wound, and with venous suppuration, within the vein. In this study, 16 of the 50 catheters (32%) were SQ culture-positive including all 5 catheters causative of septicemia ( P = 0.003). Confluent growth on the SQ plate was demonstrated in all three instances of suppurative phlebitis. The specificity and the predictive value of a positive catheter culture in diagnosis of catheter-related septicemia were substantially enhanced when compared with the conventional broth culture in this study in burn patients was associated with related septicemia at least 31% of the time. With the SQ technique, microbiologic identification and susceptibility testing of clinically significant isolates are accelerated. Knowledge of a positive SQ catheter culture in a burn patient with persistent sepsis can provide added impetus for diagnostic venotomy and definitive surgical therapy of suppurative phlebitis.

The use of hypercapnia in the study of regional cerebral blood flow abnormalities with 133Xe

Abstract Induced hypercapnia was utilized for the study of regional cerebral blood flow (rCBF) using 133 Xe inhalation. Washout data were grossly biexponential with fast and slow components representing gray and white matter, respectively. Corrected washout data were fitted to a two-compartment model using a nonlinear least squares regression to calculate rCBF. In normal patients, hypercapnia resulted in a 2–4% increase in hemispheric flow for each Torr rise in P CO 2 . In abnormal studies either a lesser increase in flow was effected, or new regional or hemispheric asymmetries were seen, or both. The use of hypercapnia increased the sensitivity of the rCBF determinations from 30 to 90% in patients with transient ischemic attacks, and from 40 to 82% in patients with other varieties of cerebrovascular disease.

The use of oral antibiotic suppression for control of infections in patients with thermal injuries

Abstract An oral antibiotic regimen aimed at suppression of colonic flora was utilized in a laminar flow burn unit. Patients receiving this regimen were compared prospectively to a similar group of patients who did not receive the regimen but were treated in an otherwise identical fashion. With the use of the antibiotic regimen, burn wound colonization was significantly delayed, the incidence of positive burn wound biopsis was halved, and infectious complications of all types occurred half as frequently. Staphylococcal and fungal enterocolitis were not seen in the patients receiving antibiotic suppression.