Residents' Knowledge regarding Recreational Drug Screening Immunoassays at a Swiss Hospital Group.

Introduction: In case of suspected acute recreational drug toxicity, immunoassays are commonly used as diagnostic tools. Although easy to handle, understanding of their limitations is necessary for a correct interpretation of the results. The aim of this project was to investigate residents' knowledge regarding drug screening immunoassays at a Swiss hospital group. Methods: All residents of a large hospital group in Switzerland were invited by e-mail to participate in an anonymous survey. Following ten multiple choice questions on drug screening tests, the participants were also asked about their demographics, whether they used drug screening tests on a regular basis, and how confident they felt in their ability to interpret test results. Results: The ten knowledge questions were answered by 110 of the 1026 residents (11%). Among the 108 participants with available demographics, 90% were 25-35 years old, 63% were female, and 70% were at least in their 4th year of residency. The median score of correct answers was 4 out of 10 (range 0-7) and in 50% of the questions, the correct answer was the most frequently selected response. No significant differences in the knowledge scores were found based on the training, confidence level, or the frequency of drug tests used in daily work. Conclusion: This survey revealed widespread knowledge gaps among residents regarding the interpretation of immunoassay-based drug test results. These findings can be used to implement educational measures on this topic and might provide a basis for targeted information on common pitfalls to be included in laboratory reports.

Pharmacokinetics and pharmacodynamics of inhaled nicotine salt and free-base using an e-cigarette: A randomized crossover study.

BACKGROUND: Popular "pod-style" e-cigarettes commonly use nicotine salt-based e-liquids that cause less irritation when inhaled and can deliver higher nicotine concentrations than free-base nicotine. We aimed to investigate the pharmacokinetic and pharmacodynamic effects of different nicotine formulations (salt vs. free-base) and concentrations that might influence systemic nicotine absorption and appeal of e-cigarettes. METHODS: In this randomized, double-blind, within-subject crossover study, 20 non nicotine-naïve participants were switched among three e-liquids (free-base nicotine 20mg/mL, nicotine salt 20mg/mL, nicotine salt 40mg/mL) using a refillable pod system and a standardized vaping protocol (one puff every 30 seconds, 10 puffs total). Serum nicotine concentrations and vital signs were assessed over 180 minutes; direct effects, craving, satisfaction, withdrawal, and respiratory symptoms were measured using questionnaires. CYP2A6 genotypes and the nicotine metabolite ratio were also assessed. RESULTS: Eleven (55%) participants were male and the median age was 23.5 years (range 18-67). All three formulations differed significantly in peak serum nicotine concentration (baseline adjusted Cmax, median (range): 12.0ng/mL (1.6-27.3), 5.4ng/mL (1.9-18.7) and 3.0ng/mL (1.3-8.8) for nicotine salt 40mg/mL, nicotine salt 20mg/mL and free-base 20mg/mL, respectively). All groups reached Cmax 2.0-2.5min (median) after their last puff. Differences in subjective effects were not statistically significant. No serious adverse events were observed. CONCLUSION: Free-base 20mg/mL formulations achieved lower blood nicotine concentrations than nicotine salt 20mg/mL, while 40mg/mL nicotine salt yielded concentrations similar to cigarette smoking. The findings can inform regulatory policy regarding e-liquids and their potential use in smoking cessation. IMPLICATIONS: Nicotine salt formulations inhaled by an e-cigarette led to higher nicotine delivery compared to nicotine free-base formulations with the same nicotine concentration. These findings should be considered in future regulatory discussions. The 40mg/mL nicotine salt formulation showed similar nicotine delivery as combustible cigarettes, albeit at concentrations over the maximum limit for e-liquids allowed in the European Union. Nicotine delivery resembling combustible cigarettes might be beneficial for smokers willing to quit to adequately alleviate withdrawal symptoms. However, increased nicotine delivery can also pose a public health risk, raising concerns about abuse liability, especially among youth and non-smokers.

Symmetrical and Mixed Tris(acyl)phosphines: Synthesis, Oxidation and Photochemistry.

Invited for the cover of this issue are the groups of M. Haas, G. Gescheidt and H. Grützmacher from the Graz University of Technology and the ETH Zürich. The image depicts a phosphorus mine, where the workers are acid chlorides using their shovels and red phosphorus to provide the chemicals necessary to produce novel reagents. Read the full text of the article at 10.1002/chem.202302535.

Symmetrical and Mixed Tris(acyl)phosphines: Synthesis, Oxidation and Photochemistry.

Herein, we present a convenient synthesis for symmetrical and mixed substituted tris(acyl)phosphines (TAPs) starting from red phosphorus. All TAPs exhibit a phosphaalkene-acylphosphine equilibrium, which was investigated in detail by variable-temperature (VT) NMR spectroscopy supported by density-functional theory (DFT) calculations. Depending on the substituents, two phosphaalkene derivatives and ten acylphosphine derivatives could be isolated. NMR spectroscopy and single-crystal X-ray crystallography enabled a clear structural assignment of these compounds. Oxidation of selected TAPs led to the formation of the corresponding tris(acyl)phosphine oxides (TAPOs). Furthermore, their spectroscopic properties as well as their photochemistry was investigated. Especially, the TAPO compounds were evaluated for their suitability as photoinitiators by CIDNP spectroscopy, photobleaching measurements and by storage stability tests.

The Inlet and Outlet Ratio: Retrospective and Prospective Study on an Improved Diagnostic Ultrasound Tool for Carpal Tunnel Syndrome.

Purpose: This study hypothesized that ratios of sonographic cross-sectional areas (CSAs) throughout the median nerve provide a more reliable tool for diagnosing carpal tunnel syndrome (CTS) than a single CSA value. We first tested this hypothesis in a retrospective cohort and subsequently confirmed it in a prospective blinded case-control series. Methods: Seventy patients were included in the retrospective study, and 50 patients and matched controls were included for the prospective study. We evaluated 4 CSAs, at the forearm, inlet, tunnel, outlet, and their ratios (Rforearm, Rinlet, Routlet, Routlet forearm) to evaluate compression of the median nerve. All patients underwent nerve conduction studies. For the prospective cohort, Disabilities of the Arm, Shoulder, and Hand scores and Boston Carpal Tunnel Questionnaire scores were evaluated, and ultrasound was performed by 2 examiners for each participant. Results: The Boston and Disabilities of the Arm, Shoulder, and Hand scores showed worse subjective function in patients with CTS than in controls. Three ultrasonography parameters (CSAs at the inlet, Rinlet, and Routlet) correlated significantly with subjective function. Age and Rinlet were significantly correlated with severity of CTS in the nerve conduction studies. In both the retrospective and prospective patient groups, the numbers of CSAs at the inlet and outlet were significantly higher than that of CSAs at the tunnel, whereas in the control group, no such compression was found. Of the single measurements, CSAs at the inlet had the best diagnostic performance with an optimized cutoff of 11.75 mm2. The Rinlet and Routlet ratios performed even better and showed the highest adjusted odds ratios for predicting CTS of all parameters (cutoff Rinlet, 1.25; Routlet, 1.45). Inter-observer correlation was generally high, with better values for single CSAs than for ratios. Conclusions: The 3 CSA measurements of the median nerve and the associated ratios improved diagnostic power for ultrasonography in CTS in our study. Type of study/level of evidence: Diagnostic I.

The Transosseous Internal Four Strand Technique: A New All-Inside Technique for Zone 1 Flexor Tendon Repairs.

BACKGROUND: Multiple techniques for the repair of flexor tendon injuries in zone 1 have been proposed over time. While pull-out suture techniques and bone anchor seem to be stronger than internal suture techniques, they are associated with a higher complication rate. We therefore developed an alternative internal suture repair with similar biomechanical stability to those of pull-out sutures and bone anchors. METHODS: Twenty porcine distal phalanges and deep flexor tendons were randomized to 2 groups of 10 each. The tendons were transsected at the level of the distal interphalangeal joint. In group 1, repairs were performed with a well-established intraosseous suture repair and in group 2 with our new multistrand technique. The repairs were biomechanically tested with linear distraction until failure. RESULTS: We recorded a significantly higher 2-mm gap force (2GF)-and thus higher stability-of the repairs in group 1 in comparison to group 2. With a 2GF of more than 50 N, our suture technique allows for a modern early active motion rehabilitation protocol. Breakage of the suture construct occurred at random places in the repair in both groups. No pull-outs were noted. CONCLUSIONS: This study presents a strong transosseous multistrand repair technique for flexor tendon repair in zone 1 that is simple and fast to perform and should have enough strength to withstand early active motion rehabilitation.

Exposure of the Lumbosacral Plexus by Using the Pararectus Approach: A Technical Note.

BACKGROUND: Surgical exploration of the lumbosacral plexus is challenging. Previously described approaches reach from invasive open techniques with osteotomy of the ilium to laparoscopic techniques. OBJECTIVE: To describe a novel surgical technique to explore lumbosacral plexopathies such as benign nerve tumors or iatrogenic lesions of the lumbosacral plexus in 4 case examples. METHODS: We retrospectively evaluated 4 patients suffering from pathologies or injuries of the lumbosacral plexus between 2017 and 2019. The mean follow-up period after surgery was 23.5 (range 11-52) months. All patients underwent neurolysis of the lumbosacral plexus using the single incision, intrapelvic, extraperitoneal pararectus approach. RESULTS: In all patients, the pathology of the lumbosacral plexus was successfully visualized, proving feasibility of the extraperitoneal pararectus approach for this indication. There were no major complications, and all patients recovered well. CONCLUSION: The pararectus approach allows excellent visualization of the lumbar plexus and intrapelvic lesions of the femoral and sciatic nerves.

Transosseous Sutures in Tendon-to-Bone Repairs: the Role of the Epitendinous Suture.

BACKGROUND: Numerous transosseous fixation techniques for flexor tendon injuries in Zone 1 of the hand have been described in the literature. While relatively high maximal loads to failure are documented in different biomechanical experiments, several tests revealed a low 2 mm gapping resistance of the tendon-to-bone repairs. We therefore aimed to investigate the effect on gap formation adding a peripheral suture to an established transosseous fixation technique. In addition, we analyzed the influence of different suture materials (braided vs. non-braided) on the stability of the core suture. METHOD: A total of 30 porcine flexor digitorum profundus tendons were divided into 3 groups (n = 10 each) and repaired using the transverse intraosseous loop technique (TILT). In group 1 and group 2 the repairs were performed using PDS 3-0 or Ethibond 3-0, respectively. In group 3, a peripheral suture was added to the core suture (PDS 3-0) consisting of two figure-of-eight stitches with PDS 5-0. The biomechanical performance of the repaired tendons was analyzed using a standardized protocol. RESULTS: The suture material and peripheral suture showed no effect on the ultimate failure load in our testing. However, the addition of a peripheral suture led to a statistically significantly higher 2 mm gap force when compared with the repair with a core suture only. CONCLUSION: In conclusion, addition of a palmar epitendinous suture to the transosseous core suture significantly increases the load to 2 mm gap formation in Zone 1 flexor tendon repairs and thus allows an immediate controlled mobilization.

Sonography, My Personal Assistant at Hand Outpatient Clinic.

Ultrasonography in hand surgery offers the option of imaging trauma consequences or degenerative problems in the wrist and fingers, involving bones, joints, ligaments, tendons, annular pulley, carpal and digital changes, soft masses, and foreign bodies including dynamic changes during motion. In the hands of the treating surgeon, ultrasonography allows immediately to plan conservative treatment versus surgery, to precisely infiltrate joints or tendon spaces as well as to perform miniinvasive assisted surgery.

Benign subcutaneous emphysema: a rare and challenging entity a case report and review of the literature.

We report the case of a craftsman who developed a rapidly progressive subcutaneous emphysema of his forearm after a minor stab injury into the palm of his hand. Based on our case report we discuss differential diagnosis and management of acute subcutaneous emphysema.

Keystone Flap Type IIIB: A New Variation for Coverage of Defects at Joint Regions.

Soft tissue defect reconstruction at joint regions is a challenging problem due to the sparse excessive tissue and late complication of constrigent scar formation. Priorly irradiated tissue, often the case in sarcoma patients, is especially problematic. The keystone design perforator island flap is safe and reliable. We now present a new keystone flap design, which is particularly suitable for the reconstruction of large soft tissue defects at joint regions. It provides a cutaneous component without the need for a skin graft and therefore minimizes the risk of contracture. Donor site morbidity is negligible. Furthermore, it offers a favorable aesthetic result compared to other flaps, eg, a muscular flap. We propose a new keystone flap design as an extension of Behan's classification, the Keystone flap type IIIb.

Delayed deep dermal necrosis after jellyfish sting in a 4-year-old female infant.

We report the case of a 4-year-old female infant who developed ongoing deep dermal necrosis of the bilateral legs after jellyfish contact in Thailand. Stepwise radical debridement and vacuum assisted wound therapy seemed to be an effective strategy to prevent progressive soft tissue loss.

Late ureteral obstruction after injection of dextranomer/hyaluronic acid copolymer.

Various biological and artificial materials have been introduced for endoscopic treatment of vesicoureteral reflux. Over the past years, dextranomer combined with hyaluronic acid (Dx/Ha) has been established as the most commonly used tissue-augmenting substance for subureteral injection because of its biocompatibility. Nevertheless, the histopathologic analysis of failed Dx/Ha injections showed changes in consistency and volume of the deposit and granulomatous reactions of the adjacent tissue. We report a case of late-onset obstruction 2 years after the injection of Dx/Ha. In the current literature, this potential long-term complication is hardly mentioned.

Dose-dependent vasodilatory effects of acetylcholine and local warming on skin microcirculation.

The assessment of the skin microvasculature response to iontophoretically applied acetylcholine (ACh) and local warming makes it possible to explore noninvasively in humans the functional integrity of endothelium. The present study aimed to examine whether these two stimuli of nitric oxide (NO) release have a dose-dependent vasorelaxant activity. For this purpose we assessed in healthy subjects using a laser-Doppler imaging system the increase in forearm blood flow following transdermal application of increasing amounts of ACh [with an iontophoretic current of either 0.28 mC/cm2 (n = 18), 0.56 mC/cm2 (n = 14), 1.4 mC/cm2 (n = 26), 7 mC/cm2 (n = 14), 28 mC/cm2 (n = 14), or 48 mC/cm2 (n = 6)] or graded warming of the skin [to either 37 degrees C (n = 8), 39 degrees C (n = 4) or 41 degrees C (n = 12)]. The maximal vasodilation was significantly smaller with the lowest dose than with the higher doses of ACh, and a plateau was reached with the 1.4 mC/cm2 dose. The skin blood flow responses to ACh were not dependent on the pulsed or continuous pattern of iontophoretic administration. The hyperemia induced by the local heating to 41 degrees C was significantly greater than that observed with the other temperatures. When measured in the same subjects, the magnitude of the maximal ACh-mediated skin blood flow increase was significantly smaller than the vasodilation associated with the warming to 41 degrees C. In summary, transdermally applied ACh and local heating of the skin induce a dose-dependent vasorelaxation. These techniques represent a unique means to investigate noninvasively the functional vasodilatory capacity of the skin microvasculature.