Procalcitonin in hemodialysis patients presenting with fever or chills to the emergency department.

We sought to assess the role of procalcitonin in discriminating severe bacterial infections requiring antibiotic treatment from non-bacterial causes of fever or chills in chronic dialysis patients. Chronic hemodialysis patients who were admitted to the emergency room due to fever and/or chills were recruited to the study. The presence or absence of bacterial infection was defined after recruitment conclusion by an infectious disease specialist who was blinded to procalcitonin results. Procalcitonin levels were compared between infected and non-infected patients. Out of 54 patients recruited, 22 (41%) patients eventually diagnosed with infection. Mean (± SD) procalcitonin values were 4.3 (± 5.5) ng/ml among cases, 1.0 (± 2.0) ng/ml among controls with no infection (p = 0.02). A cutoff PCT value of 1 ng/ml or higher had 77% sensitivity and 59% specificity for the diagnosis of severe infection. Procalcitonin cannot usefully identify hemodialysis patient with bacterial infection.

Evaluation of a prospectively administered written questionnaire to reduce the incidence of suspected latex anaphylaxis during elective cesarean delivery.

BACKGROUND: Life-threatening anaphylaxis has been reported in women exposed to latex during surgery. We compared a written screening questionnaire to identify suspected latex sensitivity with a verbal inquiry used previously in a historical control group of women undergoing cesarean delivery to determine if the incidence of suspected latex anaphylaxis could be reduced. METHODS: To identify suspected latex sensitivity among women undergoing elective cesarean delivery in a single-site tertiary unit, a nine-item written screening questionnaire was compared to historical use of a standard verbal inquiry "Are you allergic to medications or latex?". Women who had suspected latex sensitivity risk factors, or who had known latex allergy, underwent latex-free surgery. Women with suspected anaphylaxis during cesarean delivery were recommended to undergo allergen testing. The primary study outcome was suspected anaphylaxis incidence during the two periods: historical control January to December 2008, questionnaire March 2010 to April 2011. RESULTS: The questionnaire identified suspected latex sensitivity in 66 of 453 women (14.6%) who completed the questionnaire. The standard verbal inquiry group had identified 12 of 460 women (2.6%) with self-reported latex sensitivity. The incidence of suspected anaphylaxis during cesarean delivery was significantly lower during the questionnaire period when compared to historical controls (3/516, 0.6% vs. 11/460, 2.4%, P=0.015). For both groups, 13 of 14 women (92.9%) with suspected latex anaphylaxis were contactable; five of 13 (38.5%) had undergone allergen testing and all were positive for latex. CONCLUSIONS: Use of the written screening questionnaire was associated with fewer cases of suspected anaphylaxis during cesarean delivery compared with the historical control. Most women with suspected anaphylaxis did not perform allergy testing; however, all who did were positive for latex.

Computerised tomography for the detection of pulmonary emboli in intensive care patients--a retrospective cohort study.

Pulmonary emboli are frequently considered as a cause for respiratory deterioration in intensive care unit (ICU) patients, however empirical observation suggests that computerised tomographic (CT) angiography is infrequently positive after the first 24 hours. This study aimed to determine the rate and risk factors for detection of pulmonary emboli by CT angiography in ICU patients. All patients undergoing CT angiography > 24 hours after ICU admission for respiratory deterioration from April 2000 until January 2004 were included. The positivity rate for pulmonary emboli was determined and risk factors analysed. Seven (6%) out of 113 CT angiograms were positive for pulmonary emboli. All were found in trauma patients. Comparing positive to negative scans, predefined risk factors including head injury (5/7 positive scans, 71% vs. 23/106 negative scans, 22%, P = 0.005), spine injury with neurological impairment (4/7, 57% vs. 9/106, 8%, P = 0.002) and lower limb injury (3/7, 43% vs. 12/106, 9%, P = 0.039) were significantly more frequent in patients with positive scans. Deep vein thrombosis prophylaxis was employed less frequently prior to a positive scan (in 3/7, 43% patients with positive scans vs. 91/106, 86% patients with negative scans P = 0.015). Only the predefined risk factors were independently associated with positive CT angiography on limited logistic regression (OR 24.7 per risk factor, 95% CI 2.38 to 255.1, P = 0.007). Pulmonary emboli were infrequently diagnosed using CT angiography in ICU patients admitted for more than 24 hours and found only in patients with recognised risk factors.

Medical aerosol propellant interference with infrared anaesthetic gas monitors.

BACKGROUND: 1,1,1,2 Tetrafluoroethane is a hydrofluoroalkane (HFA) that is replacing chlorofluorocarbons (CFC) as a medical aerosol propellant in an attempt to reduce damage to the ozone layer. This study compared the effects of HFA- and CFC-based inhalers on four anaesthetic gas monitoring systems. METHODS: The HFA- and CFC-based inhalers were activated in close proximity to the sample line of two Datex Ohmeda, an Agilent and a Siemens infrared anaesthetic agent monitoring systems. The effects were recorded on each system for five common anaesthetic agents. RESULTS: The HFA inhaler caused either maximal false positive readings (with the exception of desflurane) or transient measurement failure on all systems. The Datex Ohmeda AS/3 system misidentified the HFA inhaler as carbon dioxide at low concentration (2 +/- 0 mm Hg). The CFC-based inhaler caused a minor false-positive reading (0.4 +/- 0%) for halothane only on the Datex Ohmeda AS/3 system only and was misidentified as carbon dioxide at 33.3 (sd 2.1) mm x Hg and 22.4 (8.9) mm x Hg by the Agilent and Siemens systems. CONCLUSIONS: The HFA inhaler adversely affected all equipment tested. The infrared spectra of HFA and the common anaesthetic gases have considerable overlap at the 8-12 microm range that is not shared by the CFCs. The differences in spectral overlap explain the different effects of the HFA and CFC propellants. Anaesthetic gas concentration data may be erroneous using the HFA-based inhalers.

The use of the arterial line as a source for blood cultures.

OBJECTIVE: To determine the reliability of blood cultures obtained through indwelling arterial lines as compared to that of blood cultures obtained by venipuncture. DESIGN: A prospective observational study. SETTING: Six-bed mixed medical surgical intensive care unit (ICU) of a 550-bed university-affiliated medical center. MEASUREMENTS: During a 3-month period blood culture sets, when clinically indicated, were drawn in parallel from indwelling arterial catheters and one-time venipuncture and the results compared. Each blood sample consisted of 15 ml and was distributed equally between three blood culture bottles: aerobic, anaerobic and one aerobic resin-containing bottle. Blood culture results from the two sources were compared according to preset definitions. MAIN RESULTS: During the study period 90 parallel blood culture sets (540 bottles) were obtained from 36 patients. Forty-three (16%) venipuncture bottles were positive versus 88 (32%) arterial line culture bottles (p < 0.001). Of the parallel sets, 83% yielded equivalent results - either both sterile or both growing the same organism. Amongst the discordant sets, the arterial line cultures grew 37 gram-positive and 18 gram-negative isolates not found in venipuncture sets (i.e. 50% of 109 arterial line isolates), while only two gram-positive isolates were solely grown in venipuncture cultures (4% of all 55 venipuncture isolates, p < 0.001). On clinical correlation, all the gram-positive organisms in the discordant cultures were found not to reflect bacteremia, while five of the 18 gram-negative isolates (28%) grown only in arterial line cultures probably did reflect ongoing bacteremia. CONCLUSION: The results of blood cultures taken from the arterial line are frequently equivalent to those taken from venipuncture. When discordant, the growth of gram-positive bacteria almost certainly reflects contamination or arterial line colonization, whereas the growth of gram-negative bacteria may have to be considered as reflecting bacteremia.

Routine surveillance blood cultures: their place in the management of critically ill patients.

The use of surveillance blood cultures has been advocated as a means to allow earlier detection of septic episodes amongst intensive care patients, and therefore earlier institution of appropriate antibiotic therapy. We compared the results of surveillance cultures and clinically indicated blood cultures for bacterial isolates grown and the influence of culture results on patient management. Blood cultures were obtained from all intensive care unit (ICU) patients over the course of 3 months at a set surveillance time (surveillance group) or according to clinical indications (clinical group). Bacteriological results were compared and real-time chart review performed to assess the influence of the surveillance cultures on patient management, with particular reference to antibiotic therapy. Two hundred and forty-nine blood culture sets were collected over 3 months, 99 in the surveillance group and 150 in the clinical group. A total of 256 bacterial isolates were grown, 95 in the surveillance group and 161 in the clinical group. For the surveillance group 36%, 20%, and 44% of the isolates represented bacteraemia, line colonization and culture contamination, respectively. For the clinical group the distibution was 69%, 7%, and 24% respectively (P<0.001, P<0.01, and P<0.0027 for comparisons of percentages within each classification). On only one occasion was antibiotic therapy started based on the result of a surveillance culture, and on only one occasion was a septic episode detected earlier by a surveillance culture; however, this culture result did not lead to a change in patient management. Surveillance blood cultures are expensive and add very little to the management of patients in the intensive care environment.

Impact of the resin blood culture medium on the treatment of critically ill patients.

OBJECTIVE: To assess the relevance, both clinical and bacteriologic, of the use of resin-containing blood culture media in blood cultures taken from critically ill patients receiving antibiotics. DESIGN: A prospective, open clinical trial. SETTING: The mixed medical surgical intensive care unit (ICU) of a 550-bed urban hospital. PATIENTS: All ICU patients admitted during a 3-month period (n = 49) with suspected sepsis requiring blood cultures as part of their laboratory investigations. INTERVENTIONS: The use of an aerobic resin-containing blood culture medium, in addition to the regular aerobic and anaerobic media for all blood cultures taken. MEASUREMENTS AND MAIN RESULTS: Each blood culture result was classified as to its clinical significance. Changes in patient management were recorded. Culture sets in which the resin-containing bottle provided the information central to the change in patient management were identified. Bacteriologically, the results from the resin-containing medium were compared with the results from the aerobic and anaerobic media. Of 266 blood culture sets, 103 (39%) were positive, growing 278 bacterial and fungal isolates. Clinically, the resin-containing medium alone provided relevant data leading to changes in patient management on three occasions. On two of these occasions, cultures from the regular media provided the same data within 72 hrs. Bacteriologically, 77 (29%) aerobic bottles, 55 (21%) anaerobic bottles, and 89 (33%) resin-containing bottles were positive (statistical comparison of percentages: aerobic vs. resin-containing bottles, nonsignificant; aerobic vs anaerobic bottles, p < .046; anaerobic vs. resin-containing bottles, p < .0027). A similar proportion of pathogens was isolated from the resin-containing bottles only (9%) and aerobic bottles only (6%). A higher proportion of contaminants was isolated from the resin-containing bottles only than the aerobic bottles only in the various sets (17% vs. 7%, p < .046). The resin-containing bottle showed a trend toward increased detection of Staphylococcus aureus and Pseudomonas aeruginosa bacteremia. CONCLUSIONS: The resin-containing medium offers little clinical benefit to the majority of ICU patients. Bacteriologically, it seems to have a similar overall sensitivity as the regular aerobic medium (with the possible exception of a higher sensitivity for the isolation of S. aureus and P. aeruginosa), but a lower specificity. The wide-spread use of the resin-containing bottle cannot be recommended.

Functional consequences of embryonic neocortex transplanted to rats with prefrontal cortex lesions.

In four experiments we reexamined the recent report by Labbe, Firl, Mufson, and Stein (1983) that fetal cortical tissue transplanted to an aspirative prefrontal cortical cavity in rats can ameliorate the learning impairments induced by the aspirative lesions. Healthy surviving grafts from young (E16) embryonic donors had no immediate effects on the rats' impairments in T-maze alternation, spatial navigation in the Morris swimming pool task, or locomotor activity, and they produced even greater impairments than the lesions alone when all three tests were conducted after longer (3-5 month) survival periods. Grafts taken from older (E21) donors did produce a short-lasting improvement in the T-maze alternation performance, replicating the previous report. However, this effect was not seen in the other two behavioral tests; the grafts survived poorly, and the beneficial effect was no longer apparent in the long-term tests. It is concluded that (a) functional benefits of embryonic cortical grafts are dependent on a precise combination of conditions rather than being a general phenomenon, and (b) the short-lasting recovery in delayed alternation performance is attributable to diffuse influences of the embryonic tissue on the lesioned host brain rather than to a reconnection of damaged circuitries.

Reconstruction of the patellar tendon using a dacron graft: a case report.

A case is presented in which a patellar tendon has undergone shortening and degeneration after rupture of a primary repair. The extensor tendon mechanism was reconstructed by using a dacron graft to substitute for the missing patellar tendon and follow-up at 15 months post-surgery showed excellent return of function. Factors in the successful outcome were thought to be both the intrinsic strength of the dacron graft and the ability of fibroblasts to infiltrate the dacron mesh to form a new tendon-like structure.

The effectiveness of various antibiotics in methyl methacrylate.

The effectiveness of different antibiotics mixed with Simplex P has been tested in vitro. A laboratory model was designed to simulate the constant immersion of bone cement in tissue fluid. Clindamycin, and to a lesser extent Cephalothin, were shown to be effective when used in this manner against Staphylococcus aureus and epidermidis. Effective inhibition of Gram-negative organisms could not be demonstrated with any of the antibiotics tested. The addition of up to 3 grams of antibiotic powder per unit of 40 grams of Simplex P did not appear to alter the expansive properties of the cement. Such release of antibiotics as did occur was thought to be related to the slow absorption of water by the slightly porous methyl methacrylate.