Defibrillation Strategies for Refractory Ventricular Fibrillation.

BACKGROUND: Despite advances in defibrillation technology, shock-refractory ventricular fibrillation remains common during out-of-hospital cardiac arrest. Double sequential external defibrillation (DSED; rapid sequential shocks from two defibrillators) and vector-change (VC) defibrillation (switching defibrillation pads to an anterior-posterior position) have been proposed as defibrillation strategies to improve outcomes in patients with refractory ventricular fibrillation. METHODS: We conducted a cluster-randomized trial with crossover among six Canadian paramedic services to evaluate DSED and VC defibrillation as compared with standard defibrillation in adult patients with refractory ventricular fibrillation during out-of-hospital cardiac arrest. Patients were treated with one of these three techniques according to the strategy that was randomly assigned to the paramedic service. The primary outcome was survival to hospital discharge. Secondary outcomes included termination of ventricular fibrillation, return of spontaneous circulation, and a good neurologic outcome, defined as a modified Rankin scale score of 2 or lower (indicating no symptoms to slight disability) at hospital discharge. RESULTS: A total of 405 patients were enrolled before the data and safety monitoring board stopped the trial because of the coronavirus disease 2019 pandemic. A total of 136 patients (33.6%) were assigned to receive standard defibrillation, 144 (35.6%) to receive VC defibrillation, and 125 (30.9%) to receive DSED. Survival to hospital discharge was more common in the DSED group than in the standard group (30.4% vs. 13.3%; relative risk, 2.21; 95% confidence interval [CI], 1.33 to 3.67) and more common in the VC group than in the standard group (21.7% vs. 13.3%; relative risk, 1.71; 95% CI, 1.01 to 2.88). DSED but not VC defibrillation was associated with a higher percentage of patients having a good neurologic outcome than standard defibrillation (relative risk, 2.21 [95% CI, 1.26 to 3.88] and 1.48 [95% CI, 0.81 to 2.71], respectively). CONCLUSIONS: Among patients with refractory ventricular fibrillation, survival to hospital discharge occurred more frequently among those who received DSED or VC defibrillation than among those who received standard defibrillation. (Funded by the Heart and Stroke Foundation of Canada; DOSE VF ClinicalTrials.gov number, NCT04080986.).

Safety and Adverse Events During Primary Care Paramedic Interfacility Transfer of Stable STEMI Patients.

OBJECTIVE: Current guidelines recommend that patients presenting with ST-elevation myocardial infarction (STEMI) to hospitals not capable of performing primary percutaneous coronary intervention (PCI) be transferred to a PCI-capable hospital if reperfusion can be accomplished within 120 min. Most STEMI patients are accompanied by an advanced care paramedic (ACP, equivalent to EMT-P), nurse, or physician who can manage complications should they arise. In our region, stable STEMI patients are transported by primary care paramedics (PCPs, similar scope of practice to advanced EMT) in cases where a nurse, physician, or ACP paramedic is not available. Our goal was to describe adverse events and need for advanced interventions among initially stable STEMI patients during interfacility transfer by PCPs. METHODS: We reviewed ambulance and hospital records of initially stable STEMI patients (as determined by first set of vital signs documented by paramedics) transferred to a PCI-capable hospital by PCPs between March 1, 2014, and December 31, 2019. We identified whether pre-determined adverse clinical events occurred during the transport as well as the potential need for advanced care interventions not within the PCP scope of practice. Adverse events upon arrival in the PCI lab were also identified. RESULTS: Of 346 STEMI patients transferred, 179 met inclusion criteria. The mean age of included patients was 61 years (SD 12.1) and 74.9% (134/179) were male. Median transport interval was 36 min (IQR 3.0). During transport, 47/179 (26.0%) patients experienced pre-defined adverse events; for 16/47 (34%), one or more adverse events was major. Three patients met criteria for ACP interventions. One patient suffered a cardiac arrest and was promptly resuscitated with defibrillation by the PCPs. CONCLUSIONS: We found PCP-interfacility transport of initially stable STEMI patients was safe and associated with a moderate proportion of adverse events, the majority of which did not require an advanced care intervention. These findings may help decision-making to avoid delays transferring stable patients to PCI-capable centers.

The Impact of Out-of-Hospital Time and Prehospital Intubation on Return of Spontaneous Circulation following Resuscitative Thoracotomy in Traumatic Cardiac Arrest.

INTRODUCTION: Resuscitative thoracotomy (RT) is a critical procedure performed in certain trauma patients in extremis, with extremely low survival rates. Currently, there is a paucity of data pertaining to prehospital variables and their predictive role in survival outcomes in traumatic cardiac arrest (TCA) patients requiring RT. The aim of the study was to determine the impact of prehospital intubation and out-of-hospital time (OOHT) on return of spontaneous circulation (ROSC) and survival in TCA requiring RT. METHODS: This was a retrospective cohort study of trauma patients presenting to two level-1 trauma centers, St. Michael's Hospital and Sunnybrook Health Sciences Center, in Toronto, Canada (January 1, 2005-December 31, 2020). Our exposures of interest were any prehospital intubation attempt and OOHT. Primary and secondary outcome measures were ROSC post-RT and survival to hospital discharge, respectively, and data analysis was performed using univariate logistic regression. RESULTS: A total of 195 patients were included, of which 86% were male, and the mean age was 33 years. ROSC and survival to hospital discharge were achieved in 30% and 5% of patients, respectively. Of those who survived to discharge, 89% sustained penetrating trauma. There was no association between OOHT and ROSC (OR = 1.00, 95% CI 0.97-1.03) or survival (OR = 0.99, 95% CI 0.94-1.05). The odds of ROSC were lower in penetrating trauma in the presence of any prehospital intubation attempt (OR = 0.39, 95% CI 0.19-0.82, p = 0.01). ROSC was less likely among all patients with no prehospital signs of life (SOL) compared to those who had prehospital SOL (OR = 0.30, 95% CI 0.13-0.69, p < 0.01). CONCLUSIONS: There was a significant association between prehospital intubation and lower likelihoods of ROSC in the penetrating TCA population requiring RT, as well as with the absence of prehospital SOL in all patients. OOHT did not appear to significantly impact ROSC or survival.

Predefibrillation end-tidal CO2 and defibrillation success in out-of-hospital cardiac arrest: an observational cohort study.

BACKGROUND: Predefibrillation end-tidal CO2 (ETCO2) may predict defibrillation success and could guide defibrillation timing in ventricular fibrillation (VF) cardiac arrest. This relationship has only been studied using advanced airways. Our aim was to evaluate this relationship using both basic (bag-valve-mask (BVM)) and advanced airways (supraglottic airways and endotracheal tubes). METHODS: Prehospital patient records and defibrillator files were abstracted for patients with out-of-hospital cardiac arrest in Ontario, Canada, with initial VF cardiac rhythms between 1 January 2018, and 31 December 2019. Analyses assessed the relationship between each predefibrillation ETCO2 reading and defibrillation outcomes at the subsequent 2 min pulse check (ie, VF, asystole, pulseless electrical activity (PEA) or return of spontaneous circulation (ROSC)), accounting for airway types used during resuscitation. Multivariable logistic regression evaluated the association between the first documented predefibrillation ETCO2 and postshock VF termination or ROSC. RESULTS: Of 269 cases abstracted, 153 had predefibrillation ETCO2 measurements and were included in the study. Among these cases, 904 shocks were delivered and 44.4% (n=401) had predefibrillation ETCO2 measured. The first ETCO2 reading was more often from BVM (n=134) than advanced airways (n=19). ETCO2 readings were lower when measured through BVM versus advanced airways (30.5 mm Hg (4.06 kPa) (±14.4 mm Hg (1.92 kPa)) vs 42.1 mm Hg (5.61 kPa) (±22.5 mm Hg (3.00 kPa)), adjANOVA p<0.01). Of all shocks with ETCO2 reading (n=401), no difference in preshock ETCO2 was found for subsequent shocks that resulted in persistent VF (32.2 mm Hg (4.29 kPa) (±15.8 mm Hg (2.11 kPa))), PEA (32.8 mm Hg (4.37 kPa) (±17.1 mm Hg (2.30 kPa))), asystole (32.4 mm Hg (4.32 kPa) (±20.6 mm Hg (2.75 kPa))) or ROSC (32.5 mm Hg (4.33 kPa) (±15.3 mm Hg (2.04 kPa))), analysis of variance p=0.99. In the multivariate analysis using the initial predefibrillation ETCO2, there was no association with VF termination on the subsequent shock (adjusted OR (adjOR) 0.99, 95% CI 0.97 to 1.02, p=0.57) or ROSC (adjOR 1.00, 95% CI 0.97 to 1.03, p=0.94) when evaluated as a continuous or categorical variable. CONCLUSION: Predefibrillation ETCO2 measurement is not associated with VF termination or ROSC when basic and advanced airways are included in the analysis. The role of predefibrillation ETCO2 requires careful consideration of the type of airway used during resuscitation.

Applying Kane's validity framework to a simulation based assessment of clinical competence.

Assessment of clinical competence is complex and inference based. Trustworthy and defensible assessment processes must have favourable evidence of validity, particularly where decisions are considered high stakes. We aimed to organize, collect and interpret validity evidence for a high stakes simulation based assessment strategy for certifying paramedics, using Kane's validity framework, which some report as challenging to implement. We describe our experience using the framework, identifying challenges, decisions points, interpretations and lessons learned. We considered data related to four inferences (scoring, generalization, extrapolation, implications) occurring during assessment and treated validity as a series of assumptions we must evaluate, resulting in several hypotheses and proposed analyses. We then interpreted our findings across the four inferences, judging if the evidence supported or refuted our proposed uses of the assessment data. Data evaluating "Scoring" included: (a) desirable tool characteristics, with acceptable inter-item correlations (b) strong item-total correlations (c) low error variance for items and raters, and (d) strong inter-rater reliability. Data evaluating "Generalizability" included: (a) a robust sampling strategy capturing the majority of relevant medical directives, skills and national competencies, and good overall and inter-station reliability. Data evaluating "Extrapolation" included: low correlations between assessment scores by dimension and clinical errors in practice. Data evaluating "Implications" included low error rates in practice. Interpreting our findings according to Kane's framework, we suggest the evidence for scoring, generalization and implications supports use of our simulation-based paramedic assessment strategy as a certifying exam; however, the extrapolation evidence was weak, suggesting exam scores did not predict clinical error rates. Our analysis represents a worked example others can follow when using Kane's validity framework to evaluate, and iteratively develop and refine assessment strategies.

Serious gaming: A tool to educate health care providers about domestic violence.

Due to many adverse health effects, victims of domestic violence are frequently seen in the health care system. Yet, health care providers may lack the training to assist them. Online curricula can be an effective instructional tool. Our competency-based, serious video game, Responding to Domestic Violence in Clinical Settings, was designed to address health care providers' knowledge gaps through 17 modules, each a half hour in length. Nearly 9,000 participants completed at least one module; nursing students completed the most modules, approximately five hours of instruction. This serious video game-based curriculum is useful in helping health providers and students learn about Domestic Violence.

A comparison of intimate partner and other sexual assault survivors' use of different types of specialized hospital-based violence services.

BACKGROUND: Little is known about the health service utilization of women sexually assaulted by their intimate partners, as compared with those sexually assaulted by other perpetrators. To address this gap, we describe the use of acute care services post-victimization, as well as a broad range of survivor and assault characteristics, across women assaulted by current or former intimate partners, other known assailants, and strangers. METHODS: Information was gathered from individuals presenting to 30 hospital-based sexual assault and domestic violence treatment centres using a standardized data collection form. We examined the data from 619 women 16 years of age or older who were sexually assaulted by one assailant. RESULTS: Women sexually assaulted by a current or former intimate partner were less likely than those assaulted by another known assailant or a stranger to have been administered emergency contraception (p < 0.001) or prophylaxis for sexually transmitted infections (p < 0.001), and counselled for potential use of HIV post-exposure prophylaxis (p < 0.001). However, these women were more likely than those in the other two groups to have had their injuries documented with photographs (p < 0.001), have undergone a risk assessment (p = 0.008), and/or have engaged in safety planning (p < 0.001). CONCLUSIONS: Women sexually assaulted by current or former intimate partners utilized services offered by sexual assault and domestic violence treatment centres differently than those assaulted by other known assailants and strangers. This may reflect their different health, forensic, and social needs, as well as the importance of offering care tailored to their particular circumstances.

Visualizing Flagella while Tracking Bacteria.

A complete description of the swimming behavior of a bacterium requires measurement of the displacement and orientation of the cell body together with a description of the movement of the flagella. We rebuilt a tracking microscope so that we could visualize flagellar filaments of tracked cells by fluorescence. We studied Escherichia coli (cells of various lengths, including swarm cells), Bacillus subtilis (wild-type and a mutant with fewer flagella), and a motile Streptococcus (now Enterococcus). The run-and-tumble statistics were nearly the same regardless of cell shape, length, and flagellation; however, swarm cells rarely tumbled, and cells of Enterococcus tended to swim in loops when moving slowly. There were events in which filaments underwent polymorphic transformations but remained in bundles, leading to small deflections in direction of travel. Tumble speeds were ∼2/3 as large as run speeds, and the rates of change of swimming direction while running or tumbling were smaller when cells swam more rapidly. If a smaller fraction of filaments were involved in tumbles, the tumble intervals were shorter and the angles between runs were smaller.

Assessment of the safety and effectiveness of emergency department STEMI bypass by defibrillation-only emergency medical technicians/primary care paramedics.

INTRODUCTION: The American Heart Association (AHA) suggests emergency medical service (EMS) providers transporting ST-segment elevation myocardial infarction (STEMI) patients to a percutaneous coronary intervention (PCI) center require advanced life support (ALS) skills. OBJECTIVES: To evaluate the potential safety and time savings effectiveness of defibrillation-only emergency medical technician/primary care paramedic (EMT-D/PCP) EMS transport to a PCI center in a system where only emergency medical technician-paramedics/advanced care paramedics (EMT-Ps/ACPs) are authorized to bypass non-PCI hospitals. METHODS: We reviewed 89 consecutive patients meeting STEMI criteria transported by EMT-Ds/PCPs per protocol by one of three paths: 1) closest non-PCI center emergency department (ED) with secondary transfer by EMT-Ps/ACPs to a PCI lab, 2) rendezvous with EMT-Ps/ACPs and diversion to a PCI lab, and 3) PCI center ED if it was closest. Actual transport times to the PCI center ED were compared to predicted transport times determined by mapping software had EMT-Ds/PCPs followed a direct path. Lastly, we recorded predefined clinically important events and advanced care interventions. RESULTS: Twenty-seven, 51, and 11 patients followed paths 1, 2, and 3 respectively. Median transport times for path 1 were 6 (IQR 5) minutes to reach the nearest non-PCI center ED and 66 (IQR 45) minutes to the PCI center ED compared to a median predicted 13 (IQR 7) minutes to a PCI center ED had EMT-Ds/PCPs followed a direct path. Median transport time for path 2 was 12 (IQR 8) minutes compared to a median predicted time of 11 (IQR 6) minutes had no EMT-P/ACP rendezvous occurred. Median transport time for path 3 was 7 minutes (IQR 5). Three patients experienced prehospital cardiac arrest; 1 required dopamine, and 4 others received a saline bolus for hypotension. CONCLUSIONS: Substantial time savings may occur if EMT-Ds/PCPs bypass non-PCI center EDs with only a small predicted increase (about 7 minutes) in the transport time to the PCI center ED. EMT-P/ACP rendezvous does not appear to substantially increase transport time. Given the relatively low occurrence of clinically important events, our findings suggest that EMT-D/PCP bypass to a PCI center ED may be safe and effective for selected STEMI patients.

Achieving attainable outcomes from good science in an untidy world: case studies in land and air pollution.

While scientific understanding of environmental issues develops through careful observation, experiment and modelling, the application of such advances in the day to day world is much less clean and tidy. Merseyside in northwest England has an industrial heritage from the earliest days of the industrial revolution. Indeed, the chemical industry was borne here. Land contamination issues are rife, as are problems with air quality. Through the examination of one case study for each topic, the practicalities of applied science are explored. An integrated, multidisciplinary response to pollution needs more than a scientific risk assessment. The needs of the various groups (from public to government) involved in the situations must be considered, as well as wider, relevant contexts (from history to European legislation), before a truly integrated response can be generated. However, no such situation exists in isolation and the introduction of environmental investigations and the exploration of suitable, integrated responses will alter the situation in unexpected ways, which must be considered carefully and incorporated in a rolling fashion to enable solutions to continue to be applicable and relevant to the problem being faced. This integrated approach has been tested over many years in Merseyside and found to be a robust approach to ever-changing problems that are well described by the management term, "wicked problems".

Association of coronary angiography with ST-elevation and no ST-elevation in patients with refractory ventricular fibrillation - A substudy of the DOuble SEquential External Defibrillation for Refractory Ventricular Fibrillation (DOSE-VF randomized control trial).

BACKGROUND: Refractory ventricular fibrillation or pulseless ventricular tachycardia (rVF/pVT) during out-of-hospital cardiac arrest (OHCA) is associated with poor survival. Double sequential defibrillation (DSED) and vector change (VC) improved survival for rVF/pVT in the DOSE-VF RCT. However, the role of angiography and percutaneous coronary intervention (angiography/PCI) during the trial is unknown. OBJECTIVES: To determine the incidence of ST-elevation (STE) and no ST-elevation (NO-STE) on post-arrest ECG and the use of angiography/PCI in patients with rVF/pVT during the DOSE-VF RCT. METHOD: Adults (≥18-years) with rVF/pVT OHCA randomized in the DOSE-VF RCT who survived to hospital admission were included. The primary analysis compared the proportion of angiography in STE and NO-STE. We performed regression modelling to examine association between STE, the interaction with defibrillation strategy, and survival to discharge controlling for known covariates. RESULTS: We included 151 patients, 74 (49%) with STE and 77 (51%) with NO-STE. The proportion of angiography was higher in the STE cohort than NO-STE (87.8% vs 44.2%, p < 0.001); similarly the proportion of PCI was also higher (75.7% vs 9.1%, p < 0.001). Survival to discharge was similar between STE and NO-STE (63.5% vs 51.9%, p = 0.15). Use of angiography/PCI did not differ between defibrillation strategies. Decreased age (OR 0.95, 95% CI 0.92-0.98; p = 0.001) and angiography (OR 9.33, 95% CI 3.60-26.94; p < 0.001) were predictors of survival; however, STE was not. CONCLUSION: We found high rates of angiography/PCI in patients with STE compared to NO-STE, however similar rates of survival. Angiography was an independent predictor of survival. Improved rates of survival employing DSED and VC were independent of angiography/PCI.

The impact of double sequential shock timing on outcomes during refractory out-of-hospital cardiac arrest.

BACKGROUND: Animal studies suggest the efficacy of double sequential external defibrillation (DSED) may depend on the interval between the two shocks, or "DSED interval". No human studies have examined this concept. OBJECTIVES: To determine the relationship between DSED interval and termination of ventricular fibrillation (VFT), return of spontaneous circulation (ROSC), survival to hospital discharge, and favourable neurological status (MRS ≤ 2) for patients in refractory VF. METHODS: We performed a retrospective review of adult (≥18 years) out-of-hospital cardiac arrest between January 2015 and May 2022 with refractory VF who received ≥1 DSED shock. DSED interval was divided into four pre-defined categories. We examined the association between DSED interval and patient outcomes using general estimated equation logistic regression or Fisher's exact test. RESULTS: Among 106 included patients, 303 DSED shocks were delivered (median 2, IQR 1-3). DSED intervals of 75-125 ms (OR 0.39, 95% CI 0.16-0.98), 125-500 ms (OR 0.36, 95% CI 0.16-0.82), and >500 ms (OR 0.27, 95% CI 0.11-0.63) were associated with lower probability of VF termination compared to <75 ms interval. DSED interval of >75 ms was associated with lower probability of ROSC compared to <75 ms interval (OR 0.37, 95% CI 0.14-0.98). No association was noted between DSED interval and survival to hospital discharge or neurologic outcome. CONCLUSIONS: Among patients in refractory VF a DSED interval of less than 75 ms was associated with improved rates of VF termination and ROSC. No association was noted between DSED interval and survival to hospital discharge or neurologic outcome.

The impact of alternate defibrillation strategies on shock-refractory and recurrent ventricular fibrillation: A secondary analysis of the DOSE VF cluster randomized controlled trial.

BACKGROUND: The DOSE VF randomized controlled trial (RCT) employed a pragmatic definition of refractory ventricular fibrillation (VF after three successive shocks). However, it remains unclear whether the underlying rhythm during the first three shocks was shock-refractory or recurrent VF. OBJECTIVE: To explore the relationship between alternate defibrillation strategies employed during the DOSE VF RCT and the type of VF, either shock-refractory VF or recurrent VF, on patient outcomes. METHODS: We performed a secondary analysis of the DOSE VF RCT. We categorized cases as shock-refractory or recurrent VF based on pre-randomization shocks (shocks 1-3). We then analyzed all subsequent (post-randomization) shocks to assess the impact of standard, vector change (VC) or double sequential external defibrillation (DSED) shocks on clinical outcomes employing logistic regression adjusted for Utstein variables, antiarrhythmics, and epinephrine. RESULTS: We included 345 patients; 60 (17%) shock-refractory VF, and 285 (83%) recurrent VF. Patients in recurrent VF had greater survival than shock-refractory VF (OR: 2.76 95% CI [1.04, 7.27]). DSED was superior to standard defibrillation for survival overall, and for patients with shock-refractory VF (28.6% vs 0%, p = 0.041) but not for those in recurrent VF. DSED was superior to standard defibrillation for return of spontaneous circulation (ROSC) and neurologic survival for shock-refractory and recurrent VF. VC defibrillation was not superior for survival or ROSC overall, for shock-refractory, or recurrent VF groups, but was superior for VF termination across all groups. CONCLUSION: DSED appears to be the superior defibrillation strategy in the DOSE VF trial, irrespective of whether the preceding VF is shock-refractory or recurrent.

The impact of prehospital continuous positive airway pressure on the rate of intubation and mortality from acute out-of-hospital respiratory emergencies.

BACKGROUND: Previous studies have demonstrated decreased rates of intubation and mortality with prehospital use of continuous positive airway pressure (CPAP). We sought to validate these findings in a larger observational study. METHODS: We conducted a before and after observational study of consecutive patients transported by emergency medical services (EMS) during the 12 months before and the 12 months following implementation of a prehospital CPAP protocol for acute respiratory distress. Included were all patients transported by EMS meeting preestablished criteria indicative of acute respiratory distress and CPAP use (patient's problem specified as cardiac, respiratory distress, respiratory disease, or congestive heart failure [CHF]; age ≥ 12 years; chest sounds documented as wheezes or rales; Glascow Coma Scale [GCS] ≥ 11; respiratory rate ≥ 24 breaths per minute; systolic blood pressure ≥ 90 mmHg; and oxygen saturation < 90%). Data were abstracted from ambulance call reports (ACRs) and hospital records. All cases in which "do not resuscitate" (DNR) was documented on the patient chart or ACR or whose in-hospital outcome (death or discharge) was unknown were excluded. RESULTS: In all, 442 patients met the above criteria. The mean (SD) age was 73.0 (13.9) years, and 51.5% were women. In-hospital mortality rates did not differ for these patients: 17/228 (7.5%) in the before group and 17/214 (7.9%) in the after group (p = 0.85). In-hospital intubation rates were similar for both groups (12.7 vs. 14.5%, p = 0.59). An analysis of the subgroup that had a hospital diagnosis of chronic obstructive pulmonary disease (COPD), CHF, or pulmonary edema (n = 273) showed mortality was somewhat lower in the before group (3/138, 2.2%) than in the after group (8/135, 5.9%) (p = 0.13). In-hospital intubation rates were also similar for both groups in this subgroup analysis (11.6 vs. 9.6%, p = 0.61). CONCLUSION: In contrast to previous studies, we were unable to demonstrate a decrease in intubation or mortality related to the use of prehospital CPAP. Our findings may be specific to our EMS system but suggest that further large-scale, randomized, controlled trials may be warranted to firmly establish the benefit of prehospital CPAP.

Clinical events and treatment in prehospital patients with ST-segment elevation myocardial infarction.

BACKGROUND: Little is known about clinically important events and advanced care treatment that patients with ST-segment elevation myocardial infarction (STEMI) encounter in the prehospital setting. OBJECTIVES: We sought to determine the proportion of community patients with STEMI who experienced a clinically important event or received advanced care treatment prior to arrival at a designated percutaneous coronary intervention (PCI) laboratory or emergency department (ED). METHODS: We reviewed 487 consecutive community patients with STEMI between May 2008 and June 2009. All patients were geographically within a single large "third-service" urban emergency medical services (EMS) system and were transported by paramedics with an advanced care scope of practice. We recorded predefined clinically important events and advanced care treatment that occurred in patients being transported directly to a PCI laboratory or ED (group 1) or interfacility transfer to a PCI laboratory (group 2). RESULTS: One or more clinically important events occurred in 92 of 342 (26.9%) group 1 patients and nine of 145 (6.2%) group 2 patients. The most common were sinus bradycardia, hypotension, and cardiac arrest. Additionally, 33 of 342 (9.6%) group 1 and nine of 145 (6.2%) group 2 patients received one or more advanced care treatments. The most common were administration of morphine and administration of atropine. Eight group 1 patients and three group 2 patients received cardiopulmonary resuscitation (CPR) or defibrillation. CONCLUSIONS: Clinically important events and advanced care treatment are common in community STEMI patients undergoing prehospital transport or interfacility transfer to a PCI center. Several patients required CPR or defibrillation. Further research is needed to define the clinical experience of STEMI patients during the out-of-hospital phase and the scope of practice required of EMS providers to safely manage these patients.

The upper surface of an Escherichia coli swarm is stationary.

When grown in a rich medium on agar, many bacteria elongate, produce more flagella, and swim in a thin film of fluid over the agar surface in swirling packs. Cells that spread in this way are said to swarm. The agar is a solid gel, with pores smaller than the bacteria, so the swarm/agar interface is fixed. Here we show, in experiments with Escherichia coli, that the swarm/air interface also is fixed. We deposited MgO smoke particles on the top surface of an E. coli swarm near its advancing edge, where cells move in a single layer, and then followed the motion of the particles by dark-field microscopy and the motion of the underlying cells by phase-contrast microscopy. Remarkably, the smoke particles remained fixed (diffusing only a few micrometers) while the swarming cells streamed past underneath. The diffusion coefficients of the smoke particles were smaller over the virgin agar ahead of the swarm than over the swarm itself. Changes between these two modes of behavior were evident within 10-20 microm of the swarm edge, indicating an increase in depth of the fluid in advance of the swarm. The only plausible way that the swarm/air interface can be fixed is that it is covered by a surfactant monolayer pinned at its edges. When a swarm is exposed to air, such a monolayer can markedly reduce water loss. When cells invade tissue, the ability to move rapidly between closely opposed fixed surfaces is a useful trait.

Asymmetry in the clockwise and counterclockwise rotation of the bacterial flagellar motor.

Cells of Escherichia coli are able to swim up gradients of chemical attractants by modulating the direction of rotation of their flagellar motors, which spin alternately clockwise (CW) and counterclockwise (CCW). Rotation in either direction has been thought to be symmetric and exhibit the same torques and speeds. The relationship between torque and speed is one of the most important measurable characteristics of the motor, used to distinguish specific mechanisms of motor rotation. Previous measurements of the torque-speed relationship have been made with cells lacking the response regulator CheY that spin their motors exclusively CCW. In this case, the torque declines slightly up to an intermediate speed called the "knee speed" after which it falls rapidly to zero. This result is consistent with a "power-stroke" mechanism for torque generation. Here, we measure the torque-speed relationship for cells that express large amounts of CheY and only spin their motors CW. We find that the torque decreases linearly with speed, a result remarkably different from that for CCW rotation. We obtain similar results for wild-type cells by reexamining data collected in previous work. We speculate that CCW rotation might be optimized for runs, with higher speeds increasing the ability of cells to sense spatial gradients, whereas CW rotation might be optimized for tumbles, where the object is to change cell trajectories. But why a linear torque-speed relationship might be optimum for the latter purpose we do not know.

Electrodermal activity at acupuncture points differentiates patients with current pain from pain-free controls.

This study evaluated whether electrodermal resistance at acupuncture points (AP) systematically varies as a function of pain. The study was conceived as a proof-of-principle study in support of research on acupuncture and other complementary medicine approaches. Specifically, this study investigates whether or not electrodermal activity systematically differentiates arthritis patients with current pain from pain-free controls. Participants with rheumatoid arthritis (n = 32) and a typical pain level of at least 3 (on a 0-10 scale) were compared with case controls (n = 28) who had no medical diagnosis and were pain free. Electrodermal resistance at AP was measured with a commercial ohmmeter and compared to heart rate, blood pressure, and ratings on the Pain Catastrophization Scale and the McGill Melzack Pain Questionnaire. There were consistent differences between the experimental group and the control group on all markers of pain. Similarly, there were significant group differences and some trends for electrodermal activity at the AP labeled 'bladder,' 'gall bladder,' and 'small intestine.' It is concluded that the concept of electrodermal resistance at AP possesses criterion validity for distinguishing pain from a no pain state. This research provides support for the usefulness of measuring electrodermal activity when testing energy-based models of disease, and can be seen as a bridge between Western and Chinese medicine.

Creating better research spaces for narratives around male family relationships and identity: guidance from rural Australian men.

INTRODUCTION: What is known about male identity or intergenerational relationships between male family members? And how can rural Australian men be engaged in essential health research? METHODS: Narrative inquiry is proposed as an ideal means for engaging in the process of uncovering men's storied reflections about their lives, relationships and identity. RESULTS: The article begins with guidance contributed by a group of rural Australian men to narrative researchers who hope to create comfortable environments for men to share personal stories about their intergenerational relationships with male relatives. The men discuss how they see themselves as men in today's Australian rural landscape. Following this, the narrative inquiry literature is discussed. Reflections are provided on male identity as influenced by culture and context, consideration of men and their family relationships, and barriers to men's participation in research, which leads to a focus on rural Australian men. CONCLUSION: Further research with rural men is called for, in regard to both their participation in research, and their participation in health initiatives.

Growth of flagellar filaments of Escherichia coli is independent of filament length.

Bacterial flagellar filaments grow at their distal ends, from flagellin that travels through a central channel ∼2 nm in diameter. The flagellin is extruded from the cytoplasm by a pump powered by a proton motive force (PMF). We measured filament growth in cells near the mid-exponential-phase with flagellin bearing a specific cysteine-for-serine substitution, allowing filaments to be labeled with sulfhydryl-specific fluorescent dyes. We labeled filaments first with a green maleimide dye and then, following an additional period of growth, with a red maleimide dye. The contour lengths of the green and red segments were measured. The average lengths of red segments (∼2.3 µm) were the same regardless of the lengths of the green segments from which they grew (ranging from less than 1 to more than 9 µm in length). Thus, flagellar filaments do not grow at a rate that decreases exponentially with length, as formerly supposed. If flagellar filaments were broken by viscous shear, the broken filaments continued to grow. Identical results were obtained whether flagellin was expressed from fliC on the chromosome under the control of its native promoter or on a plasmid under the control of the arabinose promoter.