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 To test this under simulated clinical conditions, four sets of ten random units of outdated erythrocytes at 4 to 9°C were each admixed with 250 mL 70°C 0.9 NaCl and infused through the system under a constant 300 mmHg pressure.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.     

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.     

Chondromalacia patellae: assessment with MR imaging

Magnetic resonance (MR) images of the posterior patellar hyaline articular cartilage were obtained in 23 subjects to determine if MR imaging could accurately demonstrate the patellar cartilage. Arthroscopy was used as the standard of reference. Three subjects were asymptomatic volunteers. In the remaining 20 who had patellofemoral pain, arthroscopy was performed before MR imaging in seven and afterward in 12; one did not undergo arthroscopy. MR imaging showed focal areas of swelling of the patellar cartilage, focal hypointensity, surface irregularity, areas of thinning, and areas of cartilage loss with exposure of subchondral bone. The surgical findings agreed with those from MR images in all seven patients who underwent arthroscopy before MR imaging and in ten of the 12 who underwent surgery afterward. MR imaging is an accurate means of examining the posterior patellar cartilage and should be considered as an alternative to diagnostic arthroscopy when chondromalacia patellae is suspected.     

Effects of quinidine, verapamil and nifedipine on the pharmacokinetics and pharmacodynamics of digitoxin during steady state conditions

In a prospective clinical study the effects of quinidine (Q), verapamil (V) and nifedipine (N) on the pharmacokinetics and pharmacodynamics of digitoxin (DGT) were studied in 28 subjects achieving steady state conditions. DGT plasma concentration increased continuously up to a new steady state level after 3 to 4 weeks of Q or V coadministration. Mean steady state DGT concentrations were 45% and 27%, respectively, higher than during treatment with DGT alone. Renal DGT clearance and endogeneous creatine clearance were not significantly affected by Q or V coadministration, while nonrenal DGT clearance was significantly reduced by an average of 40.5% and 29%, respectively. Similarly, elimination half-life determined in 4 volunteers once in presence and once in absence of Q was prolonged by 34.5%. The increased plasma DGT concentration seems to be pharmacodynamically active as demonstrated by electrographic measures and systolic time intervals. While the antagonistic effects of Q and V on QT-duration and myocardial performance with increasing DGT plasma levels nearly disappeared, the synergistic effects of DGT and Q or V were continuously intensified. In contrast, N had no clinically significant effect on pharmacokinetics and pharmacodynamics of DGT. From these investigations it could be concluded that Q and V had a clinically significant effect on pharmacokinetics and pharmacodynamics of DGT but to a lesser extent and, at least in part, by different mechanism than shown for digoxin.     

Über das Verhalten des Magen-Darmkanals,Insbesondere Über Darmstörungen bei Bleivergiftung

Zusammenfassung Nach Besprechung der verschiedenen Aufnahmemöglichkeiten für Blei in den menschlichen Körper werden die einzelnen Schädlichkeiten des Bleies am ganzen Verdauungstrakt von der Mundhöhle bis zum Dickdarm besprochen. Insbesondere wird auf die Frage nach dem Sitz der Bleikoliken eingegangen und diese dahin beantwortet, daß die allgemeine Ansicht von dem alleinigen Sitz der Koliken im Dickdarm abgelehnt wird zugunsten der Ansicht, daß auch die Dünndärme Sitz der Kolik bei der Bleiintoxikation sind. Hierfür sprechen sowohl die für Dünndarmsitz typischen Beschwerden als auch die klinischen Befunde, noch eindeutiger aber die Röntgenbefunde, die während der Kolik am Dünndarm beachtet wurden. Am Dickdarm ließen sich gleichzeitig keinerlei Veränderungen erkennen. Bei der von anderer Seite beobachteten stärkeren Haustrierung des Dickdarmes handelt es sich lediglich um den sog. belebten Typ, der auch bei normalen gesunden Personen häufig beobachtet wird. Die Veränderungen am Dünndarm sind spastisch-atonischer Natur und können in schweren Fällen zum Heus führen, der mit allen anderen ileusartigen Zuständen verwechselt werden kann. Zu Röntgenbildern ähnlicher Krankheitszustände wird differentialdiagnostisch Stellung genommen. Ein Vergleich zu den gleichen Dünndarmbildern bei der akuten Porphyrie wird gezogen. Bei leichteren Bleierkrankungen ohne Koliken können auch mit der Röntgenuntersuchung Veränderungen am Dünndarm festgestellt werden, die als direkt typisch bezeichnet werden können. Dann wird im einzelnen noch auf die Ursache der Dünndarmveränderungen eingegangen und die Abhandlung mit Angaben über eine wirksame Behandlung der Darmstörungen bei akuter und chronischer Bleierkrankung beschlossen.     

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.     

Pharmacokinetics of ciprofloxacin in pediatric cystic fibrosis patients.

The pharmacokinetic characteristics of ciprofloxacin were studied in 10 children with cystic fibrosis, aged from 6 to 16 years, who had completed the standard regimen of intravenous ceftazidime and amikacin. The aim of the investigation was to derive dosing guidelines for young cystic fibrosis patients to be treated with ciprofloxacin. Each child received ciprofloxacin given as two 30-min infusions (10 mg/kg of body weight each) 12 h apart; this was followed by the administration of oral ciprofloxacin (15 mg/kg every 12 h). Blood samples were taken after both infusions and after the first oral dose. A total of 232 ciprofloxacin concentrations (203 concentrations in plasma and 29 concentrations in urine) were analyzed by use of NONMEM and a two-compartment body model with seven parameters: total body clearance (CL), volume of the central compartment (V2), volume of the peripheral compartment (V3), intercompartmental clearance, renal clearance, absorption rate constant, and bioavailability. The influences of weight (range, 18 to 42 kg) and age (range, 6 to 16 years) were investigated. CL (in liters per hour) was found to be linearly correlated with weight (typical value of CL = 8.8 + 0.396. WT, where WT is weight; (interindividual coefficient of variation, 7.8%). V2 and V3 were directly proportional to weight, with slopes of 0.7 and 1.3 liters/kg, respectively. Interindividual variabilities were calculated to be 22.6 and 14.9% for V2 and V3, respectively. No dependency of the other pharmacokinetic parameters on age or weight was seen. Because of the high correlations between age and weight, only one covariable was necessary. Weight had the strongest effect. Bioavailability (population mean) was estimated to be 61.8%, and renal clearance (population mean) was estimated to be 11.4 liters/h. The residual (intraindividual) variability was 31.9%. The protein binding was about 34%, which is similar to the results obtained for adults. In order to define the appropriate dosage regimen for children suffering from cystic fibrosis, a formula was derived so that steady-state concentrations, similar to those obtained in adults after the administration of dosages of 400 mg three times daily intravenously and 750 mg twice daily orally, could be reached. The calculated total daily dose increased with increasing body weight. Given as milligrams per kilogram of body weight, the calculated dosage regimens suggest that for younger children (weight range, 14 to 28 kg), 28 to 20 mg/kg orally twice daily should be given, and for older children (weight range, 28 to 42 kg), 20 to 15 mg/kg orally twice daily should be given. For intravenous administration, dosages of 15 to 10 mg/kg twice daily are sufficient.     

Comparing position and orientation accuracy of different electromagnetic sensors for tracking during interventions

Purpose

To compare the position and orientation accuracy between using one 6-degree of freedom (DOF) electromagnetic (EM) sensor, or the position information of three 5DOF sensors within the scope of tumor tracking.

Methods

The position accuracy of Northern Digital Inc Aurora 5DOF and 6DOF sensors was determined for a table-top field generator (TTFG) up to a distance of 52 cm. For each sensor 716 positions were measured for 10 s at 15 Hz. Orientation accuracy was determined for each of the orthogonal axis at the TTFG distances of 17, 27, 37 and 47 cm. For the 6DOF sensors, orientation was determined for sensors in-line with the orientation axis, and perpendicular. 5DOF orientation accuracy was determined for a theoretical 4 cm tumor. An optical tracking system was used as reference.

Results

Position RMSE and jitter were comparable between the sensors and increasing with distance. Jitter was within 0.1 cm SD within 45 cm distance to the TTFG. Position RMSE was approximately 0.1 cm up to 32 cm distance, increasing to 0.4 cm at 52 cm distance. Orientation accuracy of the 6DOF sensor was within 1\(^\circ \), except when the sensor was in-line with the rotation axis perpendicular to the TTFG plane (4\(^\circ \) errors at 47 cm). Orientation accuracy using 5DOF positions was within 1\(^\circ \) up to 37 cm and 2\(^\circ \) at 47 cm.

Conclusions

The position and orientation accuracy of a 6DOF sensor was comparable with a sensor configuration consisting of three 5DOF sensors. To achieve tracking accuracy within 1 mm and 1\(^\circ \), the distance to the TTFG should be limited to approximately 30 cm.