Evaluation of long-term efficacy and safety of transdermal fentanyl in the treatment of chronic noncancer pain.

The objective of this international, multicenter, open-label trial was to assess the efficacy and safety of up to 12 months of therapy with transdermal therapeutic system (TTS) fentanyl in patients (n = 532) with chronic noncancer pain. The trial was completed by 301 (57%) of the patients. The main outcome measures were pain control assessment, global treatment satisfaction, patient preference for TTS fentanyl, and quality of life. The mean dose of transdermal fentanyl (TDF) increased from 48 to 90 microg/h during a period of 12 months. During treatment, on average 67% of patients within the efficacy analysis group (n = 524) reported very good, good, or moderate pain control. Global satisfaction (very good or good) was also stable at 42%. The majority (86%) of patients reported a preference for TDF over their previous treatment (P < .001, binomial test). Short Form 36 quality-of-life scores improved from baseline for bodily pain. The most frequent treatment-related adverse events were nausea (31%), constipation (19%), and somnolence (18%). With regard to opioid-specific adverse events (respiratory depression [< 1%], adrenal insufficiency [< 1%], drug abuse/dependence [1%], and opioid withdrawal syndrome [3%]), these were extremely rare and, with the exception of opioid withdrawal syndrome, none was considered definitively related to the treatment. Long-term treatment with TDF provided a stable degree of pain control in the majority of patients with moderate to severe chronic noncancer pain. It was preferred by the majority of patients compared with their previous opioid medication. Overall, long-term treatment with TDF was generally well tolerated, particularly in view of the low incidence of potentially serious side effects such as drug abuse/dependence and respiratory depression. However, at present, it is important that patients receiving TDF should still be subject to careful assessment and monitoring.

Spatial versus temporal phase shifting in electronic speckle-pattern interferometry: noise comparison in phase maps.

Temporal and spatial phase shifting in electronic speckle-pattern interferometry are compared quantitatively with respect to the quality of the resultant deformation phase maps. On the basis of an analysis of the noise in sawtooth fringes a figure of merit is defined and measured for various in-plane and out-of-plane sensitive electronic speckle-pattern interferometry configurations. Varying quantities like the object-illuminating intensity, the beam ratio, the speckle size and shape, and the fringe density allows characteristic behaviors of both phase-shifting methods to be explored.

Complex division as a common basis for calculating phase differences in electronic speckle pattern interferometry in one step.

We point out that all formulas for calculating the phase map ofobject deformations in one step can be described by the same simpleformalism of a complex division.

Spatial phase shifting in electronic speckle pattern interferometry: minimization of phase reconstruction errors.

The advantages of spatial phase shifting (SPS) compared with temporal phase shifting in the field of electronic speckle pattern interferometry are described. Some periodic phase reconstruction errors occurring in SPS are discussed. It is shown that these errors become minimal for a spatial phase-shift angle of 2pi/3. Furthermore, a modified phase reconstruction formula is presented by which the noise in the reconstructed phase map is reduced.

Spatial phase shifting for pure in-plane displacement and displacement-derivative measurements in electronic speckle pattern interferometry (ESPI).

Hitherto no method, to our knowledge, was known to incorporate spatial phase shifting for the measurement of pure in-plane displacements. We demonstrate that the modified Duffy two-aperture configuration [Opt. Lett. 22, 1958 (1996)], which is sensitive to only the in-plane displacement component and offers increased sensitivity, lends itself to measurement with spatial phase shifting. The configuration can also be used for obtaining displacement derivatives by the introduction of shear with the tilt of a mirror.

Performance of a compact, hybrid optical evanescent-wave sensor for chemical and biological applications.

We describe a hybrid evanescent-wave sensor component that we fabricated by using an integrated optical interferometer with a specially adapted photodetector array. The design of the interferometer is based on the use of tapered waveguides to obtain two intersecting collimated beams. Phase shifts can be measured with an angular precision of better than 10(-3) rad, which corresponds to a superstrate index change inferior of 10(-6) with our structure. The interest in the device as a chemical sensor is experimentally demonstrated. The same optical component could be used in a variety of other sensor applications, e.g., biological and immunological sensors.

Total intravenous anaesthesia with propofol, alfentanil, and oxygen-air: three different dosage schemes.

Three different dosage schemes of propofol infusions combined with a fixed-rate alfentanil infusion were investigated in total intravenous anaesthesia. In 30 premedicated patients, divided at random into three groups, anaesthesia was induced with propofol 2 mg.kg-1 immediately followed by an alfentanil infusion 10 micrograms.kg-1.min-1 as a loading dose which was decreased after ten minutes to a maintenance dose of 1 microgram.kg-1.min-1. Vecuronium bromide 0.1 mg.kg-1 was used as the muscle relaxant. After induction of anaesthesia a propofol infusion 2 mg.kg-1.hr-1 was started in group A, 3 mg.kg-1.hr-1 in group B and 4 mg.kg-1 hr-1 in group C. At signs of light anaesthesia supplementary bolus doses of 20 mg propofol and 1 mg alfentanil were given. The patients' lungs were ventilated with air-oxygen (FIO2 0.35). The mean systolic and diastolic blood pressures showed no statistical significant differences between the three groups. A significant (P less than 0.01) decrease of the mean systolic and diastolic blood pressures was present after induction of anaesthesia and tracheal intubation. Recovery was uneventful in all but one patient, who had ventilatory depression that responded to naloxone (0.2 mg IV). Awareness did not occur in any patient. The only difference between the three groups was the higher number of supplementary bolus doses of propofol and alfentanil needed in group A (P less than 0.01). In total intravenous anaesthesia propofol 3 and 4 mg.kg-1.hr-1 as a maintenance dose combined with a two-step fixed-rate alfentanil infusion provided smooth anaesthesia and uneventful rapid recovery.

An unusual cause of obstruction in the anesthesia circuit.

A near accident is described caused by a protection cap of an infusionset which accidentally clogged the swivel-connector in the anesthesia circuit.

Alfentanil kinetics in the elderly.

Alfentanil disposition after an intravenous bolus of 50 micrograms/kg was followed in 15 elderly surgical patients and was compared to that in nine young adults. A two-compartment open model described alfentanil disappearance from plasma. Apparent volumes of distribution of the central compartment (201 and 211 ml/kg; means), at steady state (460 and 543 ml/kg), and of the AUC (746 and 722 ml/kg) in young adults and in elderly subjects did not differ. Plasma clearance was lower in elderly subjects (4.4 ml/min/kg) than in young adults (6.5 ml/min/kg), whereas terminal plasma t1/2 was longer in the elderly patients (137 and 83 min). Alfentanil dosage should therefore be reduced in elderly patients when large single doses, multiple doses, or long-term infusions are required.

Hazard of non reinforced pre-formed tracheal tubes.

A near fatal accident is described with a non reinforced RAE tube, used because of fear of accidents previously described using armoured tubes and because of the more easy adaptation possibilities with the new RAE tubes. This report states that there is still a place for reinforced tubes.

Contributions to depth discrimination gamma-gamma-coincidence methods in scintigraphy.

Two problems in the gamma-gamma-coincidence method for depth discrimination in scintigraphy are discussed. Firstly, the FW (1/e)M of the distribution function of time differences between 'coincident' pulses is calculated to be the optimum resolving time for measurement of true coincidences. Secondly, the improvement of time resolution of such an apparatus by substituting a large volume NaI(TI) crystal by an array of many small ones is analysed. It is shown that such arrays will have no practical advantage since the loss in efficiency is of the same order of magnitude as the gain in time resolution.