Quantitative sensory testing (QST) is a noninvasive method of assessing sensory and pain perception that has been used in the past 30 years primarily for analysis of cutaneous and mucosal perception. ...In recent years, several published studies have demonstrated that QST may be useful in the analysis of painful musculoskeletal disorders as well. Based on the results of these studies, it can be postulated that QST may be useful in the analysis of the pathogenesis, classification, and differential diagnosis of musculoskeletal disorders. However, due to the diverse ethiopathogenetic basis of these disorders, a broad range of QST test batteries may be necessary to analyze the various musculoskeletal disease entities. This review analyzes published studies on this subject and summarizes current information on altered sensory and pain perception available for some of the most common musculoskeletal disorders. At present, QST remains primarily a research tool but may be useful in differential diagnosis in indicating the presence of central sensitization and for clinical monitoring of disease progression or treatment response.
Studies using quantitative sensory testing (QST) often present incongruent results due to intra‐ and intersubject as well as interobserver variability which limit widespread use of the technique. ...Eliminating or reducing the factors responsible for this variability is of great interest, as it increases reliability and reproducibility of QST. Thermal sensory threshold determination is a crucial part of QST. It was previously suggested that the pressure of the thermode on the skin could influence measurements. To verify this, we developed a new thermode with a built‐in pressure sensor. Thresholds obtained with this thermode were compared to those obtained with a commercially available thermotesting device (Medoc TSA‐II). Heat detection and heat pain detection thresholds were higher, and cold detection thresholds were lower when measured with our thermode than they were with the Medoc thermode. Cold pain detection thresholds did not differ between the thermodes. Analysis of the heat transfer capacity of the thermodes indicated that the material of the skin contact surface of the thermode may play a role in these shifts in threshold values. Altering the thermode pressure on the skin did not affect the thermal thresholds. Furthermore, the intrasubject variability of the measurements (minimal‐to‐maximal range of measured threshold values in individual subjects) was also not influenced by the pressure with which the thermode was attached to the skin. Our results suggest that the pressure with which the thermode is attached to the skin does not significantly affect the intra‐ and intersubject reproducibility of the thermal sensory threshold measurements. Muscle Nerve, 2008
Living-donated liver transplant (LDLT) patients may develop lung edema during reperfusion, requiring higher positive end-expiratory pressure (PEEP) levels, which may impair liver outflow. The aim of ...the study was to assess the effect of increased PEEP levels on venous liver outflow and systemic hemodynamics in patients after LDLT. Thirty-nine LDLT recipients were enrolled in this study. All patients were postoperatively pressure-controlled ventilated and three different PEEP levels (0, 5 and 10 mbar) were randomly set. Systemic hemodynamic parameters and flow velocities of the hepatic artery, portal vein, and right hepatic vein were recorded at each PEEP level. PEEP of 10 mbar increased significantly central venous and pulmonary capillary pressure. Flow velocities in the right hepatic vein, the portal vein, the hepatic artery, mean arterial pressure, pulmonary arterial pressure, and cardiac index were not influenced by PEEP. Our study demonstrated that PEEP up to 10 mbar did not impair liver outflow in LDLT recipients.
Evaluation of the impact of end-expiratory pressure (PEEP) ventilation on venous liver outflow, portal vein, and hepatic artery flows as well as systemic hemodynamics in patients following liver ...transplantation (LT).
Prospective, interventional patient study.
University hospital intensive care unit.
65 consecutive patients after LT.
All patients were intubated and mechanically ventilated with biphasic positive airway pressure (BIPAP). The effects of three levels of PEEP (0, 5, and 10 mbar) applied at random order on hepatic inflow and outflow were studied in the immediate postoperative period.
Central venous-, arterial pressure, and cardiac index was recorded from every patient at three different PEEP levels (0, 5, and 10 mbar). Simultaneously, flow velocities in the hepatic-, portal vein, and hepatic artery were determined by Doppler ultrasound. PEEP of 10 mbar significantly increased central venous pressure in comparison with zero PEEP. Mean arterial pressure and cardiac index was not influenced. Hepatic inflow and outflow of the transplanted livers were not impaired by any of the used PEEP levels.
BIPAP ventilation with PEEP levels up to 10 mbar does not affect systemic hemodynamics. Furthermore, neither venous outflow nor portal venous or hepatic artery inflow of the liver are impaired at PEEP levels up to 10 mbar immediately following liver transplantation. Although these results suggest that PEEP ventilation up to 10 mbar does not affect liver hemodynamics, further studies are needed to determine whether these findings could be confirmed for a longer ventilation period with PEEP.
Abstract Purpose Rescue organ offers may help to overcome the organ shortage. However, because of initial poor liver function, the recipient may develop a severe lung injury with the requirement for ...higher positive end-expiratory pressure (PEEP) levels to achieve adequate oxygenation. Positive end-expiratory pressure has been associated with perfusion impairment in the hepatosplanchnic area. We assessed the effects of increased PEEP levels on systemic hemodynamic and liver perfusion in liver transplantation (LT) patients with a rescue organ. Methods Twenty-four LT recipients of a rescue organ offer were enrolled. All patients were postoperatively mechanically ventilated with biphasic positive airway pressure, and 3 different PEEP levels (0, 5, 10 mbar) were randomly set within 4 hours after admission at the intensive care unit. Systemic hemodynamic parameters were recorded using a pulmonary artery catheter; and flow velocities of the hepatic artery, portal vein, and right hepatic vein were measured using Doppler. Results Positive end-expiratory pressure of 10 mbar did not impair the systemic hemodynamic. Flow velocities in the right hepatic vein, the portal vein, and the hepatic artery were not influenced by PEEP. Conclusion Our study demonstrates that PEEP up to 10 mbar did not impair the liver outflow in recipients with a rescue organ offer.
Design of high-power shortwave broadcast transmitters is one among the rare areas in the field of radiofrequency (RF) electronics, where the electron tube, as the main element for amplification of RF ...signal, is still in active use. The first successful attempts to replace the electron tube with solid-state components, primarily in the output stage amplifier modules for the Digital Radio Mondiale (DRM) shortwave broadcast transmitters have been published only recently. With the latest technology advancements in RF power transistors, it is now possible for commercially available RF power MOSFET transistors to be used for switching purposes at shortwave frequencies. Here, an architecture of a 10 kW shortwave broadcast transmitter with solid-state power amplifier modules in the RF output stage is proposed. Different implementations of the RF output stage that include power adding network from each amplifier module and the output matching network are analysed, both analytically and numerically. After choosing the optimal architecture, a prototype of a commercial shortwave DRM broadcast transmitter was designed and constructed, measured, tuned and tested at RIZ Transmitter factory Zagreb.
Background Transcranial direct current stimulation (tDCS) is able to modify cortical excitability and activity in humans. Objective The aim of the present study was to analyze the effects of tDCS of ...the primary sensory cortex (SI) on thermal and mechanical perception, assessed by quantitative sensory testing (QST). Methods The comprehensive QST protocol encompassing thermal and mechanical detection and pain thresholds as devised by the German Research Network on Neuropathic Pain (DFNS) was applied to skin areas innervated by the radial and median nerve of 12 healthy subjects, who were examined before and after each tDCS stimulation type. Anodal, cathodal, and sham tDCS was applied at a 1 mA current intensity with the active electrode placed over the left primary sensory cortex (SI) and the reference electrode above the right orbit for 15 minutes. Results After cathodal tDCS cold detection threshold (CDT) significantly increased in the contralateral ( P < .01) and ipsilateral hand ( P < .05) as compared to baseline condition and sham stimulation, after cathodal stimulation significantly increased warm detection threshold (WDT) was observed in the contralateral hand when compared with the baseline condition ( P < .05) but not with sham stimulation. Thermal pain as well as mechanical detection and pain thresholds remained unaltered. Conclusions Cathodal tDCS of the primary sensory cortex significantly reduced the sensitivity to Aδ-fiber-mediated cold sensation, C-fiber-mediated warm sensation was reduced only compared with baseline, whereas Aß-fiber-mediated somatosensory inputs were less affected. Our results correspond with our previous observations of primary motor cortex tDCS effects on QST parameters.
Infectious complications occur in approximately 50% of cadaveric liver transplant (CDLT) recipients. Living-donor liver transplantation (LDLT) is an established alternative to shorten the waiting ...time. Currently, the incidence of pulmonary infections after LDLT and the microbiologic causes are unknown. In the present cohort study, we compared the incidence and profiles of pulmonary and blood stream infections (BSI) between LDLT and CDLT recipients. We hypothesized a lower incidence in LDLT recipients.
The clinical course of 55 LDLT recipients consecutively transplanted between January 2003 and December 2006 was analyzed. The 173 CDLT recipients who were transplanted in the same period served as a control group. Patients were treated in a single Intensive Care Unit, applying standardized postoperative care.
Mean model for end-stage liver disease score did not differ between LDLT and CDLT recipients (14.2 vs. 13.3). The overall incidence of pulmonary and BSI for both groups was 8% and 24%, respectively. Pulmonary infections were experienced by 18% of LDLT versus 5% of CDLT recipients (P=0.005) and BSI occurred in 33% of LDLT versus 21% of CDLT recipients (P=0.1).
In contrast to our hypothesis, LDLT recipients experienced significantly more pulmonary infections and a trend toward increased higher incidence of BSI. These findings emphasize the need for future research on the causative agents and prevention of infection in LDLT recipients. The observation that patients with pulmonary infection had a significantly reduced 1-year survival rate underscores the importance of our observations.
Liver transplantation is the only curative treatment in patients with end-stage liver disease. Neurological complications (NC) are increasingly reported to occur in patients after cadaveric liver ...transplantation. This retrospective cohort study aims to evaluate the incidence and causes of NC in living donor liver transplant (LDLT) patients in our transplant center. Between August 1998 and December 2005, 121 adult LDLT patients were recruited into our study. 17% of patients experienced NC, and it occurred significantly more frequently in patients with alcoholic cirrhosis (42%) and autoimmune hepatitis (43%) as compared with patients with hepatitis B or C (9/10%,
P
= 0.013). The most common NC was encephalopathy (47.6%) followed by seizures (9.5%). The choice of immunosuppression by calcineurin inhibitor (Tacrolimus or Cyclosporin A) showed no significant difference in the incidence of NC (19 vs. 17%). The occurrence of NC did not influence the clinical outcome, since mortality rate, median ICU stay and length of hospital stay were similar between the two groups. Most patients who survived showed a nearly complete recovery of their NC. NCs occur in approximately 1 in 6 patients after LDLT and seem to be predominantly transient in nature, without major impact on clinical outcome.
Abstract Study Objective To assess the effect of positive end-expiratory pressure (PEEP) up to 15 cm H2 O on blood flow throughput of the liver and its effects on systemic hemodynamics in patients ...following liver transplantation. Design Prospective, interventional study. Setting Intensive care unit (ICU) of a university hospital. Patients 74 consecutive liver transplant recipients with a regular allocated cadaveric graft. Intervention The lungs of all study patients were postoperatively mechanically ventilated with biphasic positive airway pressure. Three different PEEP levels (5, 10, and 15 cm H2 O) were randomly set within 4 hours of admission to the ICU. Systemic hemodynamic parameters were recorded using a pulmonary artery catheter and flow velocities were measured of the hepatic artery, portal vein, and right hepatic vein using a Doppler. Measurements and Main Results PEEP of 15 cm H2 O induced a significant increase in central venous pressure and pulmonary capillary wedge pressure versus PEEP 5 cm H2 O. Flow velocities of the right hepatic vein, portal vein, and hepatic artery were not influenced by PEEP. There also was no impact of increased PEEP on mean arterial pressure or cardiac index. Conclusion PEEP up to 15 cm H2 O does not impair liver outflow or systemic hemodynamics in liver transplant patients.
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