Rapid antimicrobial susceptibility testing by VITEK®2 directly from blood cultures in patients with Gram-negative rod bacteremia.

OBJECTIVE: Optimizing therapy for bacteremia is currently limited by the 1-2-day turnaround time required for antimicrobial susceptibility testing (AST). Here, we assess a rapid AST method with VITEK®2 (bioMérieux, France) directly from positive blood cultures. METHODS: Patient-derived positive blood cultures with Gram-negative rods identified as Enterobacteriaceae and Pseudomonas aeruginosa were prospectively tested, and other blood culture bottles were spiked with carbapenem-resistant Enterobacteriaceae (CRE). Positive cultures were subjected to red blood cell lysis and centrifugation, and setup on VITEK®2. RESULTS: A total of 109 patient blood cultures and 52 spiked blood cultures were tested. Overall, essential agreement was 97.7% [95% confidence interval (CI) 96.4-99.0], and categorical agreement was 96.8% (95% CI 95.0-98.6). Mean turnaround time from setup to susceptibility results for Enterobacteriaceae in the clinical cultures was 9.0 (±1.3) h. CONCLUSIONS: Direct susceptibility testing of blood cultures by VITEK®2 for Enterobacteriaceae is an accurate, practical, and inexpensive diagnostic strategy for rapid automated AST.

Axial and rotational alignment of the leg.

The axial and rotational alignments of the lower extremity are commonly referenced independently, with minimal research on whether coexistent axial and rotational malalignment cause pathologies. The present study analyzed whether a correlation exists between the axial and rotational alignments of the leg. The methodology to measure both alignments was adapted for computer tomography. Fifty patients were analyzed at five reference images to determine axial and rotational alignment. The reference images included the femoral head, the femoral shaft (at the level of the lesser trochanter), the distal femur, the proximal tibia, and the ankle joint. Axial alignment was calculated by using horizontal and vertical measurements of the location of the femoral head, the distal femur, and the ankle joint. Rotational alignments of femur, knee, and tibia were calculated using four angles: proximal femoral, distal femoral, proximal tibial, and ankle joint angles defined relative to a fixed reference. Pearson correlation analysis between axial alignment and the three mentioned rotational alignments were calculated. The correlation coefficient values ranged between -0.15-0.07 when comparing axial to rotational alignment, indicating that a week correlation exists between the two alignments. Though these results were derived using highly reproducible methods, the hypothesis of an existing correlation between the axial and rotational alignments of the leg was rejected. These findings allow for an improved understanding of lower extremity mechanics, which merit importance when considering pathologies of the leg and the surgical techniques that could ultimately benefit patients suffering from these pathologies.

High-frequency audibility: benefits for hearing-impaired listeners.

The present study was a systematic investigation of the benefit of providing hearing-impaired listeners with audible high-frequency speech information. Five normal-hearing and nine high-frequency hearing-impaired listeners identified nonsense syllables that were low-pass filtered at a number of cutoff frequencies. As a means of quantifying audibility for each condition, Articulation Index (AI) was calculated for each condition for each listener. Most hearing-impaired listeners demonstrated an improvement in speech recognition as additional audible high-frequency information was provided. In some cases for more severely impaired listeners, increasing the audibility of high-frequency speech information resulted in no further improvement in speech recognition, or even decreases in speech recognition. A new measure of how well hearing-impaired listeners used information within specific frequency bands called "efficiency" was devised. This measure compared the benefit of providing a given increase in speech audibility to a hearing-impaired listener to the benefit observed in normal-hearing listeners for the same increase in speech audibility. Efficiencies were calculated using the old AI method and the new AI method (which takes into account the effects of high speech presentation levels). There was a clear pattern in the results suggesting that as the degree of hearing loss at a given frequency increased beyond 55 dB HL, the efficacy of providing additional audibility to that frequency region was diminished, especially when this degree of hearing loss was present at frequencies of 4000 Hz and above. A comparison of analyses from the "old" and "new" AI procedures suggests that some, but not all, of the deficiencies of speech recognition in these listeners was due to high presentation levels.

Cardiac disability. The impact of coronary heart disease on patients' daily activities.

We studied 100 men with clinically stable coronary heart disease. Their capacity for exertion as defined by treadmill test was compared with the physical and social avocational activities they carried out in their daily routine, as reported by them. Exercise capacity (treadmill time) was strongly correlated with a physician's independent assessment of symptomatic status (anginal history). Although participation in some relatively strenuous elective activities was related slightly to exercise capacity, participation in many household duties and social undertakings bore no relationship to exercise capacity or to other measures of the severity of the underlying heart disease. The patients' own perceptions of their cardiac limitation varied for different activities and for some activities it was determined as much by their own concern and outside advice as by cardiac symptoms. Decreased capacity for exertion seems to exert surprisingly little influence on a cardiac patient's daily routine and interventions aimed at altering one of these measures of performance will not necessarily affect the other.