Effect of stroboscopic vision on depth jump performance in female NCAA Division I volleyball athletes.

Anticipation of ground reaction force (GRF) in depth jumping requires multisensory integration of exteroceptive, vestibular, and proprioceptive inputs. Vision contributes to the anticipation of GRF in drop landings and may influence depth jump performance when disrupted. The purpose of this investigation was to evaluate the effects of stroboscopic vision on depth jump performance. Thirteen female NCAA Division I volleyball athletes completed a testing protocol consisting of 0.38 m depth jumps under condition of full vision and stroboscopic vision at strobe frequencies of 4 and 1.75 Hz. Depth jump performance was assessed via the Reactive Strength Index (RSI) and time-series vertical GRF (vGRF) data. Main effects of stroboscopic vision were evaluated for statistical significance via Repeated Measures Multivariate Analysis of Variance with post hoc multiple paired t-tests (α = 0.05). RSI (p < 0.001) and rebound jump height (p = 0.006) were lower in the 1.75 Hz stroboscopic condition versus full vision, while ground contact time (p = 0.008), and rate of vertical ground reaction force development (p = 0.016) were greater in the 1.75 Hz stroboscopic condition versus full vision. Stroboscopic vision could be used to modify the intensity of depth jumping and considered for inclusion into plyometric training.

Can Altering Grip Technique and Bag Size Optimize Volume Delivered with Bag-Valve-Mask by Emergency Medical Service Providers?

INTRODUCTION: Emergency Medical Services (EMS) professionals rely on the bag-valve-mask (BVM) to provide life-saving positive-pressure ventilation in the prehospital setting. Multiple emergency medicine and critical care studies have shown that lung-protective ventilation protocols reduce morbidity and mortality. A recent study has shown that the volumes typically delivered by EMS professionals with the adult BVM are often higher than recommended by lung-protective ventilation protocols. Our primary objective was to determine if a group of EMS professionals could reduce the volume delivered by adjusting the way the BVM was held. Secondary objectives included 1) if the adjusted grip allowed for volumes more consistent with lung-protection ventilation strategies and 2) comparing volumes to similar grip strategies used with a smaller BVM. METHODS: A patient simulator of a head and thorax was used to record respiratory rate, tidal volume, peak pressure, and minute volume delivered by participants for 1 minute each across 6 different scenarios: 3 different grips (using the thumb and either 3 fingers, 2 fingers, or one finger) with 2 different sized BVMs (adult and pediatric). Trials were randomized by blindly selecting a paper with the scenario listed. A convenience sample of EMS providers was used based on EMS provider and research staff availability. RESULTS: We enrolled 50 providers from a large, busy, urban hospital-based EMS agency a mean 8.60 (SD = 9.76) years of experience. Median volumes for each scenario were 836.0 mL, 834.5 mL, and 794 mL for the adult BMV (p = 0.003); and 576.0 mL, 571.5 mL, and 547.0 mL for the pediatric BVM (p < 0.001). Across all 3 grips, the pediatric BVM provided more breaths within the recommended volume range for a 70 kg patient (46.4% vs. 0.4%; p < 0.001) with only a 1.1% of breaths below the recommended tidal volume. CONCLUSION: The study suggests that it is possible to alter the volume provided by the BVM by altering the grip on the BVM. The tidal volumes recorded with the pediatric BVM were above recommended range in 2 of the 3 grips. The volumes of the pediatric BVM were overall more consistent with lung-protective ventilation volumes when compared to all 3 finger-grips of the adult BVM.

qSOFA Has Poor Sensitivity for Prehospital Identification of Severe Sepsis and Septic Shock.

OBJECTIVES: Sepsis is a common and deadly disease process for which early recognition and intervention can significantly improve clinical outcomes. Despite this, sepsis remains underrecognized and therefore undertreated in the prehospital setting. Recent recommendations by the Society of Critical Care and European Society of Intensive Care Medicine advocate use of the qSOFA (quick Sequential [Sepsis-related] Organ Failure Assessment) score in non-ICU settings to screen for septic patients at greater risk for poor outcomes. METHODS: We retrospectively evaluated the sensitivity and specificity of a prehospital qSOFA score ≥ 2 for prehospital identification of patients with severe sepsis or septic shock. Emergency Department (ED) patients with confirmed or suspected infection were classified as having infection without sepsis (n = 71), sepsis (n = 38), or severe sepsis/septic shock (n = 43), where designation of severe sepsis/septic shock required evidence of end-organ dysfunction, hypoperfusion (lactate > 2), or vasopressor requirement. RESULTS: We found that a prehospital qSOFA score ≥ 2 was 16.3% sensitive (95% CI 6.8-30.7%) and 97.3% specific (95% CI 92.1-99.4%) for patients ultimately confirmed to have severe sepsis/septic shock in the ED. Adding an additional point to the prehospital qSOFA score for a pulse > 100, nursing home residence, age > 50, or reported fever increased the sensitivity to 58.1% (95% CI 42.1-73.0%) and decreased the specificity to 78.0% (95% CI 69.0-85.4%). During their ED stay, approximately two-thirds of patients meeting severe sepsis/septic shock criteria eventually met qSOFA criteria with a sensitivity of 67.4% (95% CI 51.5-80.9) and specificity of 86.2% (95% CI 78.3-92). Failure to meet qSOFA criteria prehospital was predominantly due to a systolic blood pressure and respiratory rate that did not yet meet predetermined thresholds. CONCLUSIONS: These findings suggest that the dynamic nature of sepsis can make sensitive detection difficult in the prehospital setting, although combining qSOFA with other clinical information (age, nursing home status, fever, and tachycardia) can identify more patients with sepsis who may benefit from time critical interventions.

Can EMS Providers Provide Appropriate Tidal Volumes in a Simulated Adult-sized Patient with a Pediatric-sized Bag-Valve-Mask?

INTRODUCTION: In the prehospital setting, Emergency Medical Services (EMS) professionals rely on providing positive pressure ventilation with a bag-valve-mask (BVM). Multiple emergency medicine and critical care studies have shown that lung-protective ventilation protocols reduce morbidity and mortality. Our primary objective was to determine if a group of EMS professionals could provide ventilations with a smaller BVM that would be sufficient to ventilate patients. Secondary objectives included 1) if the pediatric bag provided volumes similar to lung-protective ventilation in the hospital setting and 2) compare volumes provided to the patient depending on the type of airway (mask, King tube, and intubation). METHODS: Using a patient simulator of a head and thorax that was able to record respiratory rate, tidal volume, peak pressure, and minute volume via a laptop computer, participants were asked to ventilate the simulator during six 1-minute ventilation tests. The first scenario was BVM ventilation with an oropharyngeal airway in place ventilating with both an adult- and pediatric-sized BVM, the second scenario had a supraglottic airway and both bags, and the third scenario had an endotracheal tube and both bags. Participants were enrolled in convenience manner while they were on-duty and the research staff was able to travel to their stations. Prior to enrolling, participants were not given any additional training on ventilation skills. RESULTS: We enrolled 50 providers from a large, busy, urban fire-based EMS agency with 14.96 (SD = 9.92) mean years of experience. Only 1.5% of all breaths delivered with the pediatric BVM during the ventilation scenarios were below the recommended tidal volume. A greater percentage of breaths delivered in the recommended range occurred when the pediatric BVM was used (17.5% vs 5.1%, p < 0.001). Median volumes for each scenario were 570.5mL, 664.0mL, 663.0mL for the pediatric BMV and 796.0mL, 994.5mL, 981.5mL for the adult BVM. In all three categories of airway devices, the pediatric BVM provided lower median tidal volumes (p < 0.001). CONCLUSION: The study suggests that ventilating an adult patient is possible with a smaller, pediatric-sized BVM. The tidal volumes recorded with the pediatric BVM were more consistent with lung-protective ventilation volumes.

Asynchronous expression of the homeodomain protein CUX1 in Sertoli cells and spermatids during spermatogenesis in mice.

The homeodomain CUX1 protein exists as multiple isoforms that arise from proteolytic processing of a 200-kDa protein or an alternate splicing or from the use of an alternate promoter. The 200-kDa CUX1 protein is highly expressed in the developing kidney, where it functions to regulate cell proliferation. Transgenic mice ectopically expressing the 200-kDa CUX1 protein develop renal hyperplasia associated with reduced expression of the cyclin kinase inhibitor p27. A 55-kDa CUX1 isoform is expressed exclusively in the testes. We determined the pattern and timing of CUX1 protein expression in developing testes. CUX1 expression was continuous in Sertoli cells from prepubertal testes but became cyclic when spermatids appeared. In testes from mature mice, CUX1 was highly expressed only in round spermatids at stages IV-V of spermatogenesis, in both spermatids and Sertoli cells at stages VI-X of spermatogenesis, and only in Sertoli cells at stage XI of spermatogenesis. While most of the seminiferous tubules in wild-type mice were between stages VI and X of spermatogenesis, there was a significant reduction in the percentage of seminiferous tubules between stages VI and X in Cux1 transgenic mice and a significant increase in the percentage of seminiferous tubules in stages IV-V and XI. Moreover, CUX1 was not expressed in proliferating cells in testes from either wild-type or transgenic mice. Thus, unlike the somatic form of CUX1, which has a role in cell proliferation, the testis-specific form of CUX1 is not involved in cell division and appears to play a role in signaling between Sertoli cells and spermatids.