Using the BBraun BSmartTM Pressure Manometer to Prevent Unsafe Injection Pressures During Simulated Peripheral Nerve Blockade: A Pilot Study

Background: Peripheral nerve injury during regional anaesthesia may result from accidental intraneural placement of the needle, or forceful needle nerve contact. Intraneural injections are associated with increased resistance to injection, typically >15 psi. The BBraun BSmart™ is an inline mechanical manometer, offering a visual display of injection pressures. Objective: The primary objective of this study was to determine if using the BBraun BSmartTM manometer successfully prevents 90% of anaesthetists and anaesthetic assistants from injecting at pressures > 15 psi during simulated nerve block. Methods: This was a prospective observational study involving anaesthetists and anaesthetic assistants. Two 20 ml injections were performed by each participant, once when the BBraun BSmartTM manometer was obscured from view, and once with the manometer visible. A PendoTech PressureMATTMS recorded injection pressures. Results: 39 participants completed the study, with a total of 78 injections recorded. During the study, 32 peak pressures during the 78 procedures were recorded above the recommended upper limit of 15 psi, 41% of the total injections. The peak pressure rose above 15 psi in 24/39 (62%) injections when the BBraun Bsmart™ manometer was obscured, but only in 8/39 (21%) injections when the manometer was visible. Conclusion: The BBraun Bsmart™ manometer did not successfully prevent 90% of anaesthetists or anaesthetic assistants from injecting at unsafe pressures. However, using the BBraun BSmart™ did reduce the number of unsafe injection pressures generated by participants. When utilised in conjunction with PNS and ultrasound guidance, this may offer additional safety during peripheral nerve blockade.

A preclinical feasibility study of endoscopic barostat: A possible diagnostic tool for visceral hypersensitivity in functional dyspepsia

Introduction: Diagnosing functional dyspepsia requires excluding organic disease and gastrointestinal function evaluation; however, there are no modalities to evaluate these simultaneously. This preclinical study examined the possibility of an endoscopic barostat. Methods: Ultrathin endoscopy and our newly developed pressure-regulated endoscopic insufflator, which insufflates the gastrointestinal tract until the preset pressure is achieved, were used. The actual intragastric pressure was measured using an optical fiber manometer placed in the stomach. Experiment-1: in an ex vivo experiment, we insufflated the isolated stomach and verified whether the intragastric pressure reached the preset pressure. Experiment-2: we inserted the endoscope orally in a porcine stomach, insufflated the stomach, and verified whether the intragastric pressure reached the preset pressure. Finally, we insufflated the stomach at a random pressure to verify the functional tests for proof-of-concept. Results: Experiment-1: the intragastric pressure reached the preset pressure. After reaching the plateau, the pressure remained stable at the preset pressure (Huber M-value: 1.015, Regression line: 0.988, 95% confidence interval [CI]: 0.994–0.994). Experiment-2: the intragastric pressure reached the preset pressure. After reaching the plateau, the pressure remained stable at the preset pressure (Huber M-value: 1.018, Regression line: 0.971, 95% CI: 0.985–0.986). At randomly preset pressures, the transendoscopic theoretical intragastric pressure detected by the insufflator was correlated with the actual pressure measured by the pressure manometer. Conclusions: This proof-of-concept study shows that a pressure-regulated endoscopic insufflator provides stable intragastric pressure at the preset level, with the potential of an endoscopic barostat to assess visceral the hypersensitivity related to functional dyspepsia.

Reduction of Hydraulic Friction in Confined Flows by Laser Texturing: Experiments and Theoretical Validation

Hydraulic friction reduction in a microchannel due to superhydrophobic texturing of its walls was studied theoretically and experimentally. A modified Poiseuille equation formulated from an earlier-established semi-analytical approach to model texturing of slip lengths and the “gas cushion model” was used to predict the hydraulic conductance of a microchannel. An experimental setup with a microfluidic flow cell consisting of syringe pump, pressure manometer and tubing measured the pressure drop at different flow rates through a microchannel. The top and bottom walls of the microchannel was textured with micro-pits using nanosecond pulsed laser on the titanium alloy Ti6Al4V. A very high contact angle was observed on the textured surfaces suggesting entrapped gas bubbles. Liquid slippage leading to reduced hydraulic friction is attributable to the bubbles. The pressure-flow rate characteristics of the microchannels confirm friction reduction and also demonstrate a reasonable agreement with the theoretical predictions from the developed fluid dynamic model.

A bélrendszer kézi és gépi anastomosisainak nyomással szembeni ellenálló képességének felmérése. In vitro kísérletes tanulmány

Intoduction and aim: The aim of the study was to compare the resistance to pressure of stapled and manually handsewn intestinal suture lines on in vitro pig intestine model. Method: We performed different types of stapled and manual sutures and the pressure level was measured using a differential pressure manometer. Results: Although the hand-sewn end-to-end suture turned out to be the most resistant to pressure, statistical analysis revealed no significant differences compared to stapled suture (p = 0.49). In stump closure techniques, we observed a statistically high significance in resistance to pressure in the favour of manual stump closure (p = 0.004).Regarding side-to-side sutures we did not find any statistically significant differences in resistance to pressure between the techniques (p = 0.06). Conclusion: We can conclude that regarding the stump closure, the most resistant to pressure is the hand-sewn procedure, but in the other types of anastomosis, no significant differences was found between the stapled and hand-sewn techniques. Orv Hetil. 2017; 158(42): 1674–1680.

Benefits of Manometer in Non-Invasive Ventilatory Support

IntroductionEffective ventilation during cardiopulmonary resuscitation (CPR) is essential to reduce morbidity and mortality rates in cardiac arrest. Hyperventilation during CPR reduces the efficiency of compressions and coronary perfusion.ProblemHow could ventilation in CPR be optimized? The objective of this study was to evaluate non-invasive ventilator support using different devices.MethodsThe study compares the regularity and intensity of non-invasive ventilation during simulated, conventional CPR and ventilatory support using three distinct ventilation devices: a standard manual resuscitator, with and without airway pressure manometer, and an automatic transport ventilator. Student’s t-test was used to evaluate statistical differences between groups. P values <.05 were regarded as significant.ResultsPeak inspiratory pressure during ventilatory support and CPR was significantly increased in the group with manual resuscitator without manometer when compared with the manual resuscitator with manometer support (MS) group or automatic ventilator (AV) group.ConclusionThe study recommends for ventilatory support the use of a manual resuscitator equipped with MS or AVs, due to the risk of reduction in coronary perfusion pressure and iatrogenic thoracic injury during hyperventilation found using manual resuscitator without manometer.LacerdaRS, de LimaFCA, BastosLP, VincoAF, SchneiderFBA, CoelhoYL, FernandesHGC, BacalhauJMR, BermudesIMS, da SilvaCF, da SilvaLP, PezatoR. Benefits of manometer in non-invasive ventilatory support. Prehosp Disaster Med. 2017;32(6):615–620.

Achieving the Recommended Endotracheal Tube Cuff Pressure: A Randomized Control Study Comparing Loss of Resistance Syringe to Pilot Balloon Palpation

Background. Both under- and overinflation of endotracheal tube cuffs can result in significant harm to the patient. The optimal technique for establishing and maintaining safe cuff pressures (20–30 cmH2O) is the cuff pressure manometer, but this is not widely available, especially in resource-limited settings where its use is limited by cost of acquisition and maintenance. Therefore, anesthesia providers commonly rely on subjective methods to estimate safe endotracheal cuff pressure. This study set out to determine the efficacy of the loss of resistance syringe method at estimating endotracheal cuff pressures. Methods. This was a randomized clinical trial. We enrolled adult patients scheduled to undergo general anesthesia for elective surgery at Mulago Hospital, Uganda. Study participants were randomized to have their endotracheal cuff pressures estimated by either loss of resistance syringe or pilot balloon palpation. The pressures measured were recorded. Results. One hundred seventy-eight patients were analyzed. 66.3% (59/89) of patients in the loss of resistance group had cuff pressures in the recommended range compared with 22.5% (20/89) from the pilot balloon palpation method. This was statistically significant. Conclusion. The loss of resistance syringe method was superior to pilot balloon palpation at administering pressures in the recommended range. This method provides a viable option to cuff inflation.

Immediate Effects of Acupuncture on Tongue Pressure Including Swallowing Reflex Latency in Parkinson's Disease

Background It is important to evaluate tongue function in terms of its clinical implications for swallowing ability. Motor dysfunction and loss of coordination of the tongue are frequently seen, and this influences the oral and pharyngeal phases of swallowing. The purpose of this pilot study was to evaluate the effect of a single acupuncture treatment for tongue pressure in Parkinson's disease. Methods A total of 13 patients, aged 57– 84 years, were recruited. Tongue pressure was measured using a tongue pressure manometer. Furthermore, swallowing reflex latency was measured in 3 of the 13 patients. Results Significant changes were seen after acupuncture in mean tongue pressure, which increased from 23.1 to 26.7 kPa (p<0.01). Reductions were seen after acupuncture in mean swallowing reflex latency (from 5.2 to 4.6 s for first saliva swallow; from 19.9 to 15.7 s for second saliva swallow; and from 10.4 to 5.7 s for third saliva swallow(s)). Conclusions Our study's findings suggest that acupuncture may be useful for improving oral cavity function, but further controlled trials are needed.