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From 2012–2015, Advanced Placement (AP) science courses underwent a large-scale curricular reform to include more scientific inquiry and reasoning, reduce emphasis on broad content coverage, and fo...

Introduction: Emergency field ventilation using bag-valve face mask devices can be difficult to perform, especially in bearded individuals. In view of the increasing numbers of servicemen and civilians sporting a beard or moustache, the issue of finding a technical solution for ventilation in this population has gained importance. We therefore developed a novel adaptor that enables the direct connection of a bag-valve device to a Guedel-type oropharyngeal airway device thereby directly connecting the oral airway to the bag valve, eliminating the need for a face mask. The objective of this study was to compare the efficacy of the bag-valve-Guedel adaptor (BVGA) to the common face mask in healthy bearded volunteers. Methods: This study was a randomized-by-sequence, crossover-controlled trial (NCT02768246) approved by the local IRB (0051-16-HMO). All subjects signed an informed consent before participation. Twenty-five healthy bearded men (age 28 ± 7) were recruited. After randomization, the first group (mask then BVGA, n = 12) began breathing room air through the face mask, followed by 100% O2. After washout in room air, the procedure was repeated with the BVGA. The second group (BVGA then mask, n = 13) began with the BVGA followed by the face mask. Subjects were awake and breathed spontaneously throughout the experiment. Therefore, a Guedel was not used. Physiological and respiratory parameters were monitored continuously. The primary endpoint was the presence of suspected leak as determined by end-tidal-CO2 (EtCO2 0.05 by Mann-Whitney-U test); therefore, the data were pooled. There were no cases of suspected leak while breathing through the BVGA. By contrast, while breathing through a face mask, there were 8 of 25 (32%) and 5 of 25 (20%) cases of suspected leak in air and 100% O2, respectively (air: p = 0.002; 100% O2: p = 0.014 by McNemar test). No adverse events were observed. Conclusions: In bearded individuals, the BVGA provides significantly more efficient (less leak) ventilation compared to a face mask. This is also of particular importance in view of the increasing number of bearded individuals serving in the armed forces. Moreover, since effective ventilation with a mask requires experience, the relatively easy-to-apply BVGA will enable less experienced first responders to achieve higher success rates in this critical phase of treatment. Further studies are planned to evaluate the efficacy of the BVGA in the prehospital setting.

Purpose Remote Ischemic preconditioning (RIPC) involves deliberate, brief interruptions of blood flow to increase the tolerance of distant critical organs to ischemia. This study tests the effects of limb RIPC in a porcine model of controlled hemorrhage without replacement therapy simulating an extreme field situation of delayed evacuation to definitive care.Methods Twenty-eight pigs (47±6kg) were assigned to: (1) control, no procedure (n=7); (2) HS=hemorrhagic shock (n=13); and (3) RIPC+HS=remote ischemic preconditioning followed by hemorrhage (n=8). The animals were observed for 7 hours after bleeding without fluid replacement. Results Survival rate between animals that underwent RIPC before bleeding and those bled without prior RIPC were similar (HS, 6 of 13[46%]-vs-RIPC+HS, 4 of 8[50%], p=0.86 by Chi-square). Animals with prior RIPC had faster recovery of mean arterial pressure and developed higher heart rates without complications. Those with RIPC had less decrease in pH and bicarbonate, and the increase in lactate began later. Global oxygen delivery was higher, and tissue oxygen extraction ratio lower, in animals bled after RIPC. Conclusions These improvements after RIPC in hemodynamic and metabolic status provide essential substrates for improved cellular response after hemorrhage and reduction of the likelihood of potentially catastrophic consequences of the accompanying ischemia.

The anesthesia delivery system is a frequent source of critical incidents, most of which (fortunately) do not lead to adverse outcomes. The most common cause of critical incidents is use error; pure failure of equipment is less frequent. This chapter presents a systematic review of potential hazards associated with the use of anesthesia gas delivery equipment. With the proliferation of computer-based systems, cybersecurity is becoming of increasing importance and an introduction to the basic concepts is included.

Waste anesthesia gases leave the breathing system and ultimately are vented into the atmosphere. The waste gas scavenging system safely interfaces the anesthesia breathing system with the hospital vacuum or other gas disposal system. Trace concentrations of anesthetic gases are still debated as a potential health hazard to personnel working in the operating room (OR).

Normally, the upper airway adds heat and moisture to inspired air. When dry medical gases bypass the upper airway via an endotracheal tube, the normal heat and moisture exchange function is compromised. This function may be replaced in two ways. First, heat and humidity can be actively added with a heated humidifier; second, and more commonly, heat and moisture may be passively retained using a heat and moisture exchanger (HME).The upper airway also filters and expels particles, including bacteria and viruses, from inspired gas. The anesthesiologist is responsible for minimizing the risk of infection from inhaled microorganisms. The use of HME filters (HMEFs) protects patients from inhaled microorganisms and also protects the anesthesia breathing system from the patient.

A number of gases are delivered and measured during anesthesia. They may serve therapeutic or diagnostic purposes. The principles and technologies behind the measurement of oxygen, carbon dioxide, nitrous oxide, potent volatile inhaled anesthetic agents, and other gases are reviewed. Different gas sampling modalities (e.g., mainstream and sidestream), and the addition of flow measurement allowing volumetric measurements are discussed. A range of applications for gas monitoring in the anesthesia setting are highlighted. An overview of algorithmic aspects of respiratory gas analysis, particularly breath detection and filtering, is presented.

Additional file 1: Table S1. A tabular time-series representation of the intensity measured at each volume across time.

Introduction: Penetrating abdominal injury is a major cause of death in trauma. It may cause hypovolemia leading to tissue hypoperfusion, direct organ damage and cytokine activation that cause inflammatory damage, all of which lead to death. Alginate is a natural anionic polysaccharide typically derived from brown algae. Sodium alginate hydrogel, a hemostatic agent, offers a platform for targeting both mechanical and biological injuries. The current study assessed the effect of a sodium alginate denoted VLVG (Very Low Viscosity (high) G alginate) following abdominal trauma in a swine model of penetrating abdominal injury. Methods: Seven anesthetized pigs were instrumented with catheters and abdominal trauma was introduced by laparoscopic hepatectomy. Ten minutes after the induction of hypovolemic shock, three animals were intra-abdominally administered with VLVG and four animals with saline (controls). During 8h of continuous monitoring, various hemodynamic and biochemical variables were measured and liver biopsies for histological evaluation were taken. In order to compare the study group to the control in a specific time a-parametric Mann-Whitney test was used, assessment of tendency during time Friedman's test for a-parametric variables was used. In order to compare the effect of the treatment (i.e. normal saline VS VLVG alginate) repeated measures ANOVA model was used, and the p value was calculated based on the Greenhouse-Geiser test. This research was approved by the Hebrew University of Jerusalem ethics Committee number: MD16148533. Results: VLVG-treated animals were more hemodynamically stable vs controls as reflected by their lower heart rate and higher blood pressure. They also had lower levels of liver enzymes and lactate and tissue damage. Conclusions: Our results in this pilot abdominal injury model show that VLVG might be a promising new agent. The superior hemostatic and biocompatibility efficiency along with its tissue preserving properties may turn VLVG in the future to a device that could be used in the pre-hospital setting to improve survival of abdominal trauma injuries.

BACKGROUND Ambulatory blood pressure monitoring (ABPM) using cuff-based devices is used for diagnosis and treatment of hypertension. Technical limitations, low compliance, and complex procedures limit their use. The aim of the present study was to test the accuracy of a new photoplethysmography-based, wearable device (Wrist-monitor) as compared with the standard cuff-based ABPM device. METHODS Twenty-four-hour (24H) ABPM was performed in parallel for both devices on volunteers aged 18–65 years, while documenting their daily activities. Level of comfort and activity disturbance of both devices were recorded. Linear regression and Bland–Altman were used to evaluate the agreement between devices. Receiver operating characteristic (ROC) curve analysis was used to classify hypertension based on the average Wrist-monitor measurements as compared with a cuff-based ABPM device. RESULTS The study included 28 subjects (18 men) mean age 41.5 ± 16.2 years. Bland–Altman analysis resulted in 24H bias of −1.1 mm Hg for both diastolic blood pressure (DBP) and systolic blood pressure (SBP). Mean daytime bias was −1.9 mm Hg for DBP and SBP, while nighttime bias was smaller (0.7 and 0.4 mm Hg for DBP and SBP, respectively). ROC curve analysis yielded a mean area under the curve (AUC) of 1 for SBP and 24H blood pressure measurements. AUCs of 0.994 and 0.955 were found for the daytime DBP and night DBP, respectively. 24H ABPM with the Wrist-monitor caused significantly less inconvenience compared with the cuff-based device (P < 0.001). CONCLUSIONS The cuffless device provides comparable measurements to those obtained with the currently used cuff-based ABPM device, with significantly less inconvenience to the subject. Clinical trials registration Trial Number NCT03810586.