Acute experimental cerebral ischemia: MR enhancement using Gd-DTPA

The effects of a paramagnetic contrast agent, gadolinium-DTPA (Gd-DTPA), on magnetic resonance (MR) imaging of acute cerebral ischemia was investigated in a feline model of middle cerebral artery occlusion. Imaging was performed both before and after administration of an intravenous dose of 0.2 mmol/kg of Gd-DTPA. The animals were then sacrificed for pathologic correlation. No changes in intensity or relaxation times were noted before or after Gd-DTPA administration in two animals with 2 hours of occlusion. Infarcts were noted before and after contrast enhancement in all six cats with ischemia of greater than 16-hours duration. Gd-DTPA caused significant increase in intensity of infarct but not in that of normal cerebral tissue. Rapid enhancement was visible in infarcts of 16-24 hours, but such enhancement was slower in infarcts of 72-168 hours, presumably owing to slowed inflow caused by increased vasogenic edema in the latter group. Contrast enhancement of acute cerebral ischemic lesions with Gd-DTPA offers no improvement in sensitivity of MR imaging, although the conspicuity of the lesion may be improved. Additionally, contrast media may provide potential temporal and pathophysiological data for better characterization of cerebral ischemia.     

Confirmation of high blood flow rates through 150 μ filter/high-flow tubing

Many new products designed to assist in rapid blood infusion are appearing. Some highly touted and routinely used devices for intravenous (IV) infusion have recently been shown to be, at least in part, defective. A tubing with an in-line 150 μ filter (150 μ High-Flow Blood Filter; Saftifllter^® Blood Administration Sets; Cutter Biological, Berkeley, CA 94710) has recently been introduced to facilitate rapid blood transfusion. It is claimed that at least 8.5 units of blood can be rapidly run through each set before replacement is necessary. To test this under simulated clinical conditions, four sets of ten random units of outdated erythrocytes at 4 to 9°C were each admixed with 250 mL 70°C 0.9 NaCl and infused through the system under a constant 300 mmHg pressure. Two sets infused through unmodified tubing flowed at an average of 25 mL/sec (1500 mL/min) before there was an appreciable slowing of the flow rate. Two sets with 8 Fr catheters attached infused at an average of 22 mL/sec (1320 mL/min) before there was an appreciable slowing of the flow rate. Even after the flow slowed, the 9th and 10th units infused at an average greater than 10 mL/sec (600 ml/min). The tubing/filter exceeded the manufacturer's published claims. This tubing/filter appears to be one element that could be an effective component of a high-flow infusion system.     

A failed fall prevention study in an acute care setting: Lessons from the swamp

Designing and implementing fall intervention studies in acute care settings presents researchers with a number of challenges. To date, there are no fall prevention interventions that have unequivocal empirical support in these settings. Based on the best available evidence a multistrategy fall prevention program was implemented using a pretest-post-test design over a 12-month period. The results indicated no reduction in the fall rate. Contrary to the expected result, the fall rate increased post the implementation of the multistrategy fall prevention program. To assist other researchers understand the contextual and methodological barriers to conducting fall prevention research in acute care settings, this paper discusses the difficulties experienced in this study.     

Transient synovitis of the hip in children: role of US

Transient synovitis of the hip remains a common diagnostic problem for the clinician. The physical signs are not pathognomonic of the condition, and the classic technical examinations are of little help. Therefore, the authors retrospectively studied the value of hip arthrosonography in 46 children with clinical symptoms suggesting pathologic hip conditions. In 20 of the 21 patients with a final diagnosis of transient synovitis, articular effusion was detected on ultrasound (US). Conventional radiography showed an increased medial joint space in only eight of these patients. Increased echogenicity of the articular fluid was found in both transient synovitis and septic arthritis. The high sensitivity of US in detecting intraarticular fluid was demonstrated by cadaver studies.     

The impact of a quadrivalent human papillomavirus (types 6, 11, 16, 18) virus-like particle vaccine in European women aged 16 to 24

Background  Quadrivalent human papillomavirus (HPV types 6/11/16/18) L1 VLP vaccine is highly effective in preventing HPV 6/11/16/18-related cervical and external genital disease. Herein, we evaluated the impact of the quadrivalent HPV 6/11/16/18 L1 VLP vaccine on prevention of HPV-associated cervico-genital lesions in a broad population of sexually active European women.
Methods  Female subjects ( N = 9265) aged 16–24 with four or fewer lifetime sexual partners were enrolled and randomized to quadrivalent HPV vaccine or placebo. Subjects underwent cervicovaginal sampling for HPV DNA detection. Papanicolaou testing and anti-HPV 6/11/16/18 serology testing was also performed.
Results  Vaccine efficacy against lesions representing immediate cervical cancer precursors (cervical intraepithelial neoplasia grade 2/3 or adenocarcinoma in situ ) related to HPV 6/11/16/18 in the per-protocol population was 100.0%[95% confidence interval (95% CI), 89.8–100.0]. Efficacy against external genital lesions (vulvar or vaginal intraepithelial neoplasia, condyloma, vulvar or vaginal cancer) related to vaccine HPV types in the per-protocol European population was 99.0% (95% CI, 94.4–100.0).
Conclusion  These data demonstrate that quadrivalent HPV 6/11/16/18 vaccination programs in 16- to 24-year-old European women can be beneficial.
NCT0009252, NCT00092534, NCT00092495     

Assessment of baroreflex sensitivity in patients with preserved and impaired left ventricular function by means of the Valsalva manoeuvre and the phenylephrine test

The purpose of the present study was to assess the agreement between measurements of baroreflex sensitivity (BRS) obtained by the Valsalva manoeuvre and by the phenylephrine test in patients with previous myocardial infarction and different degrees of left ventricular dysfunction. Patients with a previous myocardial infarction were enrolled consecutively into two groups according to their left ventricular ejection fraction (LVEF): 40% (n=52). All patients underwent BRS assessment by the phenylephrine technique (Phe-BRS) and by the Valsalva manoeuvre, with the latter using both the overshoot part of phase IV (Ov-VM-BRS) and the whole of phase IV (IV-VM-BRS). The linear association between methods was assessed by correlation analysis and the agreement was evaluated by computing the bias and the limits of agreement. IV-VM-BRS and Ov-VM-BRS could not be computed in 26% and 39% of patients respectively. For both indices a much higher percentage of non-computable Valsalva manoeuvre slopes was found in the group of patients with LVEF 40% the results were: r=0.91 (P<0.001), bias=0.1 ms/mmHg (P=0.84) and limits of agreement from -4.8 to 5 ms/mmHg. When comparing Phe-BRS and IV-VM-BRS, we found r=0.67 (P=0.001), bias=-1.5 ms/mmHg (P=0.06) and limits of agreement from -8.8 to 5.7 ms/mmHg in the group of patients with LVEF 40%. Dichotomizing Ov-VM-BRS, the best cut-off value to identify patients with a Phe-BRS of <3 ms/mmHg was found to be 7 ms/mmHg, giving 100% sensitivity and 69% specificity. In conclusion, estimation of BRS by the Valsalva manoeuvre in post-myocardial infarction patients is limited by a large number of non-measurable results. When computable, measurements are well correlated with those obtained by Phe-BRS, but, because of large limits of agreement, the two methods cannot be used interchangeably. If used as a screening test for risk stratification, the Valsalva manoeuvre could reduce by about one-third the need for phenylephrine injection.     

Use of recombinant human erythropoietin to assist autologous blood donation by anemic rheumatoid arthritis patients undergoing major orthopedic surgery

BACKGROUND: In rheumatoid arthritis (RA) patients undergoing orthopedic surgery, anemia is the major factor in the use of allogeneic blood. STUDY DESIGN AND METHODS: To determine whether recombinant human erythropoietin (rHuEPO) could allow preoperative autologous blood procurement and reduce allogeneic blood exposure, 11 RA patients who were unable preoperatively to deposit blood for autologous use because of their anemia (baseline hematocrit < 34% [0.34]) and who were scheduled for primary total hip replacement or total knee replacement were treated intravenously with 300 U per kg of rHuEPO in combination with intravenous iron saccharate (100 mg), given twice weekly for 3 weeks. The transfusion treatment was compared with that in 12 control patients with comparable baseline hematologic values who underwent the same operation. RESULTS: Control patients could not preoperatively deposit any blood for autologous use, while all but one of the rHuEPO- treated patients deposited 2 or more units (mean, 2.6 +/− 0.6; range, 2- 4) (p < 0.001). The control group received more allogeneic units (2.6 +/− 1.6 vs. 0.8 +/− 0.8) (p = 0.009). Moreover, 50 percent of the rHuEPO-treated patients, as compared with 8 percent of controls, completely avoided allogeneic transfusion. CONCLUSION: Recombinant human erythropoietin is safe and effective in stimulating erythropoiesis, allowing preoperative donation of blood for autologous use, and reducing exposure to allogeneic blood for RA patients who are unable preoperatively to deposit blood because of anemia.