Safety and predictors of the success of lumbar punctures performed by a medicine procedure service.

BACKGROUND: Medicine procedure services (MPS) increasingly perform bedside procedures, including lumbar punctures (LPs). Success rates and factors associated with LP success performed by MPS have not been well described. OBJECTIVE: We identified patients undergoing LP by an MPS September 2015 to December 2020. We identified demographic and clinical factors, including patient position, body mass index (BMI), use of ultrasound, and trainee participation. We performed multivariable analysis to identify factors associated with LP success and complications. MAIN OUTCOME AND MEASURES: We identified 1065 LPs among 844 patients. Trainees participated in 82.2%; ultrasound guidance was used in 76.7% of LPs. The overall success rate was 81.3% with 7.8% minor and 0.1% major complications. A minority of LPs were referred to radiology (15.2%) or were traumatic (11.1%). In multivariable analysis, BMI > 30 kg/m2 (odds ratio [OR] 0.32, 95% confidence interval [CI] 0.21-0.48), prior spinal surgery (OR 0.50, 95% CI 0.26-0.87), and Black race (OR 0.62, 95% CI 0.41-0.95) were associated with decreased odds of successful LP; trainee participation (OR 2.49, 95% CI 1.51-4.12) was associated with increased odds. Ultrasound guidance (OR 0.53, 95% CI 0.31-0.89) was associated with lower odds of traumatic LP. RESULTS: In a large cohort of patients undergoing LP by an MPS, we identified high success and low complication rates. Trainee participation was associated with increased odds of success, while obesity, prior spinal surgery, and Black race were associated with decreased odds of success. Ultrasound guidance was associated with lower odds of a traumatic LP. Our data may help proceduralists in planning and assist in shared decision-making.

A wearable sensor for the detection of sodium and potassium in human sweat during exercise.

The SwEatch platform, a wearable sensor for sampling and measuring the concentration of electrolytes in human sweat in real time, has been improved in order to allow the sensing of two analytes. The solid contact ion-sensitive electrodes (ISEs) for the detection of Na+ and K+ have been developed in two alternative formulations, containing either poly(3,4-ethylenedioxythiophene) (PEDOT) or poly(3-octylthiophene-2,5-diyl) (POT) as a conductive polymer transducing component. The solution-processable POT formulation simplifies the fabrication process, and sensor to sensor reproducibility has been improved via partial automation using an Opentron® automated pipetting robot. The resulting electrodes showed good sensitivity (52.4 ± 6.3 mV/decade (PEDOT) and 56.4 ± 2.2 mV/decade (POT) for Na+ ISEs, and 45.7 ± 7.4 mV/decade (PEDOT) and 54.3 ± 1.5 mV/decade (POT) for K+) and excellent selectivity towards potential interferents present in human sweat (H+, Na+, K+, Mg2+, Ca2+). The 3D printed SwEatch platform has been redesigned to incorporate a double, mirrored fluidic unit which is capable of drawing sweat from the skin through passive capillary action and bring it in contact with two independent electrodes. The potentiometric signal generated by the electrodes is measured by an integrated electronics board, digitised and transmitted via Bluetooth to a laptop. The results obtained from on-body trials on athletes during cycling show a relatively small increase in sodium (1.89 mM-2.97 mM) and potassium (3.31 mM-7.25 mM) concentrations during the exercise period of up to 90 min.

Fabrication of Rugged and Reliable Fluidic Chips for Autonomous Environmental Analyzers Using Combined Thermal and Pressure Bonding of Polymethyl Methacrylate Layers.

The fabrication of highly reliable and rugged fluidic chips designed for use in autonomous analyses for nutrient monitoring is described. The chips are based on a two-layer configuration with the fluidic channels produced in one layer using precision micromilling. The second capping layer contains through holes for sample/standard and reagent addition and waste removal post-analysis. Two optically clear polymethyl methacrylate (PMMA) windows are integrated into the opaque PMMA chip, orthogonal to a 22.5 mm-long section of the channel downstream from a serpentine reagent and sample/standard mixing region. An LED source is coupled into the channel through one of the windows, and the light intensity is monitored with a photodiode located at the distal end of the channel outside the second optically clear window. Efficient coupling of the source through the channel to the detector is achieved using custom-designed alignment units produced using 3D printing. In contrast to fluidic chips produced using solvent adhesion, the thermal-/pressure-bonded simplified method presented removes the need for surface treatment. Optimization of the thermal/pressure conditions leads to very strong adhesion between the PMMA layers, requiring forces in the region of 2000 N to separate them, which is necessary for the use in long-term deployments. Profilometry imaging shows minimal evidence of channel distortion after bonding. Finally, we show the potential of these techniques for environmental applications. The fluidic chips were integrated into prototype nutrient analyzers that display no evidence of leakage in extensive lab tests involving 2500 phosphate measurements using the yellow (vanadomolybdophosphoric acid) method. Similarly, excellent analytical performance (LOD is 0.09 µM) is reported for a 28-day field trial comprising 188 in situ autonomous phosphate measurements (564 measurements) in total including calibration.

Things We Do For No Reason: Echocardiogram in Unselected Patients with Syncope.

Syncope is a common cause of emergency department visits and hospitalizations. Echocardiogram is frequently used as a diagnostic tool in the evaluation of syncope, performed in 39% to 91% of patients. The diagnostic yield of echocardiogram for detecting clinically important abnormalities in patients with a normal history, physical examination, and electrocardiogram (ECG), however, is extremely low. In contrast, echocardiograms performed on patients with syncope with a positive cardiac history, abnormal examination, and/or ECG identify an abnormality in up to 29% of cases, though these abnormalities are not always defi nitively the cause of symptoms. Recently updated clinical guidelines for syncope management from the American College of Cardiology now recommend echocardiogram only if initial history or examination suggests a cardiac etiology, or ECG is abnormal. Universal echocardiography in patients with syncope exposes a signifi cant number of patients to unnecessary testing and cost and does not represent evidence-based or high-value patient care.