Femoral Arterial Doppler Use During Active Cardiopulmonary Resuscitation.

STUDY OBJECTIVE: This study explored femoral arterial Doppler during active cardiopulmonary resuscitation (CPR) to identify and characterize the resumptions of cardiac activity without stopping CPR. METHODS: This was a proof-of-concept study exploring arterial Doppler during cardiac arrest. Patients in cardiac arrest undergoing active CPR were prospectively enrolled. Arterial Doppler of the common femoral artery was recorded during CPR and during pauses in CPR. CPR-induced arterial tracings and native cardiac-induced tracings were analyzed for rate and peak systolic velocity. Cardiac activity on echocardiogram during pause in CPR was classified as "absent," "disorganized," or "organized." Descriptive data and survival are presented as mean and 95% confidence intervals (CI), as well as sensitivity and specificity of Doppler during active CPR in detecting native cardiac pulsations. RESULTS: Sixteen patients with 48 paired Doppler recordings during active CPR, pause in CPR, and associated echocardiogram were enrolled. Native cardiac-induced tracings were visible during 39.6% of pauses in CPR (19 of 48) and during 18.8% of the periods of active CPR (9 of 48). Arterial pulsations were more frequently visualized with organized contractions by echocardiogram (10 of 14, 71%) than disorganized contractions (9 of 22, 41%). Arterial Doppler was 100% specific and 50% sensitive in detecting organized cardiac activity during active CPR. Patients with visible native cardiac pulsations during active CPR demonstrated 0% mortality compared with 67% mortality without visible arterial pulsations. CONCLUSION: Arterial Doppler tracings may identify the resumption of native cardiac activity during active CPR; however, more research is needed.

A Multicenter, Prospective Study Comparing Subxiphoid and Parasternal Views During Brief Echocardiography: Effect on Image Quality, Acquisition Time, and Visualized Anatomy.

BACKGROUND: Recent literature has suggested echocardiography (echo) may prolong pauses in chest compressions during cardiac arrest. OBJECTVES: We sought to determine the impact of the sonographic approach (subxiphoid [SX] vs. parasternal long [PSL]) on time to image completion, image quality, and visualization of cardiac anatomy during echo, as performed during Advanced Cardiac Life Support. METHODS: This was a multicenter, randomized controlled trial conducted at 29 emergency departments (EDs) assessing the time to image acquisition and image quality between SX and PSL views for echo. Patients were enrolled in the ED and imaged in a simulated cardiac arrest scenario. Clinicians experienced in echo performed both SX and PSL views, first view in random order. Image quality and time to image acquisition were recorded. Echos were evaluated for identification of cardiac landmarks. Data are presented as percentages or medians with interquartile ranges (IQRs). RESULTS: We obtained 6247 echo images, comprising 3124 SX views and 3123 PSL. Overall time to image acquisition was 9.0 s (IQR 6.7-14.1 s). Image acquisition was shorter using PSL (8.8 s, IQR 6.5-13.5 s) compared with SX (9.3 s, IQR 6.7-15.0 s). The image quality was better with the PSL view (3.86 vs. 3.54; p < 0.0001), twice as many SX images scoring in the worst quality category compared with PSL (8.6% vs. 3.7%). Imaging of the pericardium, cardiac chambers, and other anatomic landmarks was superior with PSL imaging. CONCLUSIONS: Echo was performed in < 10 s in > 50% of patients using either imaging technique. Imaging using PSL demonstrated improved image quality and improved identification of cardiac landmarks.

Tools for Measuring Clinical Ultrasound Competency: Recommendations From the Ultrasound Competency Work Group.

Competency in clinical ultrasound is essential to ensuring safe patient care. Competency in clinical ultrasound includes identifying when to perform a clinical ultrasound, performing the technical skills required for ultrasound image acquisition, accurately interpreting ultrasound images, and incorporating sonographic findings into clinical practice. In this concept paper, we discuss the advantages and limitations of existing tools to measure ultrasound competency. We propose strategies and future directions for assessing competency in clinical ultrasound.

Abscess Incision and Drainage With or Without Ultrasonography: A Randomized Controlled Trial.

STUDY OBJECTIVE: We hypothesize that clinical failure rates will be lower in patients treated with point-of-care ultrasonography and incision and drainage compared with those who undergo incision and drainage after physical examination alone. METHODS: We performed a prospective randomized clinical trial of patients presenting with a soft tissue abscess at a large, academic emergency department. Patients presenting with an uncomplicated soft tissue abscess requiring incision and drainage were eligible for enrollment and randomized to treatment with or without point-of-care ultrasonography. The diagnosis of an abscess was by physical examination, bedside ultrasonography, or both. Patients randomized to the point-of-care ultrasonography group had an incision and drainage performed with bedside ultrasonographic imaging of the abscess. Patients randomized to the non-point-of-care ultrasonography group had an incision and drainage performed with physical examination alone. Comparison between groups was by comparing means with 95% confidence intervals. The primary outcome was failure of therapy at 10 days, defined as a repeated incision and drainage, following a per-protocol analysis. Multivariate analysis was performed to control for study variables. Our study was designed to detect a clinically important difference between groups, which we defined as a 13% difference. RESULTS: A total of 125 patients were enrolled, 63 randomized to the point-of-care ultrasonography group and 62 to physical examination alone. After loss to follow-up and misallocation, 54 patients in the ultrasonography group and 53 in the physical examination alone group were analyzed. The overall failure rate for all patients enrolled in the study was 10.3%. Patients who were evaluated with ultrasonography were less likely to fail therapy and have repeated incision and drainage, with a difference between groups of 13.3% (95% confidence interval 0.0% to 19.4%). Abscess locations were predominantly torso (21%), buttocks (21%), lower extremity (18%), and axilla or groin (16%). There was no difference in baseline characteristics between groups relative to abscess size, duration of symptoms before presentation, percentage with cellulitis, and treatment with antibiotics. CONCLUSION: Patients with soft tissue abscesses who were undergoing incision and drainage with point-of-care ultrasonography demonstrated less clinical failure compared with those treated without point-of-care ultrasonography.

Learning curves in emergency ultrasound education.

OBJECTIVES: Proficiency in the use of bedside ultrasound (US) has become standard in emergency medicine residency training. While milestones have been established for this training, supporting data for minimum standard experience are lacking. The objective of this study was to characterize US learning curves to identify performance plateaus for both image acquisition and interpretation, as well as compare performance characteristics of learners to those of expert sonographers. METHODS: A retrospective review of an US database was conducted at a single academic institution. Each examination was scored for agreement between the learner and expert reviewer interpretation and given a score for image quality. A locally weighted scatterplot smoothing method was used to generate a model of predicted performance for each individual examination type. Performance characteristics for expert sonographers at the site were also tracked and used in addition to performance plateaus as benchmarks for learning curve analysis. RESULTS: There were 52,408 US examinations performed between May 2007 and January 2013 and included for analysis. Performance plateaus occurred at different points for different US protocols, from 18 examinations for soft tissue image quality to 90 examinations for right upper quadrant image interpretation. For the majority of examination types, a range of 50 to 75 examinations resulted in both excellent interpretation (sensitivity > 84% and specificity > 90%) and good image quality (90% the image quality benchmark of expert sonographers). CONCLUSIONS: Educational performance benchmarks occur at variable points for image interpretation and image quality for different examination types. These data should be considered when developing training standards for US education as well as experience requirements for US credentialing.

Correlation of corrected flow time in the carotid artery with changes in intravascular volume status.

PURPOSE: Assessment of volume status remains a challenge in critical care. Our purpose was to determine if Doppler waveform analysis of carotid artery blood flow correlates with changes in volume status. MATERIALS AND METHODS: Dehydrated patients receiving an intravenous fluid bolus were enrolled with exclusions including age less than 18 years, pregnancy, vasopressor administration, or atrial fibrillation. Ultrasound examination with Doppler analysis of the carotid artery was performed with measurements taken to calculate corrected flow time (FTc). Corrected flow time, mean arterial pressure, and pulse rate before and after fluid administration were compared using Wilcoxon matched-pairs signed rank test. RESULTS: Fifty-six patients were enrolled with mean fluid administration of 1110 mL. Corrected flow time increased with fluid resuscitation from prefluid mean of 299 milliseconds (95% confidence interval [CI], 282-317 milliseconds) to a postfluid mean of 340 milliseconds (95% CI, 323-358 milliseconds) (P<.0001). Mean percentage change in FTc was 14.9% (95% CI, 8.4-21.3). There were no significant changes in mean arterial pressure or heart rate from pre- to post-fluid administration. CONCLUSION: Intravenous fluid administration in dehydrated patients resulted in significant changes in FTc in the carotid artery despite no change in vital signs. Corrected flow time measured from carotid arterial blood flow may be a useful means of assessing volume status in volume-depleted patients.

The Massachusetts abscess rule: a clinical decision rule using ultrasound to identify methicillin-resistant Staphylococcus aureus in skin abscesses.

OBJECTIVES: Treatment failure rates for incision and drainage (I&D) of skin abscesses have increased in recent years and may be attributable to an increased prevalence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Previous authors have described sonographic features of abscesses, such as the presence of interstitial fluid, characteristics of abscess debris, and depth of abscess cavity. It is possible that the sonographic features are associated with MRSA and can be used to predict the presence of MRSA. The authors describe a potential clinical decision rule (CDR) using sonographic images to predict the presence of CA-MRSA. METHODS: This was a pilot CDR derivation study using databases from two emergency departments (EDs) of patients presenting to the ED with uncomplicated skin abscesses who underwent I&D and culture of the abscess contents. Patients underwent ultrasound (US) imaging of the abscesses prior to I&D. Abscess contents were sent for culture and sensitivity. Two independent physicians experienced in soft tissue US blinded to the culture results and clinical data reviewed the images in a standardized fashion for the presence or absence of the predetermined image characteristics. In the instance of a disagreement between the initial two investigators, a third reviewer adjudicated the findings prior to analysis. The association between the primary outcome (presence of MRSA) and each sonographic feature was assessed using univariate and multivariate analysis. The reliability of each sonographic feature was measured by calculating the kappa (κ) coefficient of interobserver agreement. The decision tree model for the CDR was created with recursive partitioning using variables that were both reliable and strongly associated with MRSA. RESULTS: Of the total of 2,167 patients who presented with skin and soft tissue infections during the study period, 605 patients met inclusion criteria with US imaging and culture and sensitivity of purulence. Among the pathogenic organisms, MRSA was the most frequently isolated, representing 50.1% of all patients. Six of the sonographic features were associated with the presence of MRSA, but only four of these features were reliable using the kappa analysis. Recursive partitioning identified three independent variables that were both associated with MRSA and reliable: 1) the lack of a well-defined edge, 2) small volume, and 3) irregular or indistinct shape. This decision rule demonstrates a sensitivity of 89.2% (95% confidence interval [CI] = 84.7% to 92.7%), a specificity of 44.7% (95% CI = 40.9% to 47.8%), a positive predictive value of 57.9 (95% CI = 55.0 to 60.2), a negative predictive value of 82.9 (95% CI = 75.9 to 88.5), and an odds ratio (OR) of 7.0 (95% CI = 4.0 to 12.2). CONCLUSIONS: According to our putative CDR, patients with skin abscesses that are small, irregularly shaped, or indistinct, with ill-defined edges, are seven times more likely to demonstrate MRSA on culture.

Pulmonary effects of intravenous atropine induce ventilation perfusion mismatch.

Atropine is used for a number of medical conditions, predominantly for its cardiovascular effects. Cholinergic nerves that innervate pulmonary smooth muscle, glands, and vasculature may be affected by anticholinergic medications. We hypothesized that atropine causes alterations in pulmonary gas exchange. We conducted a prospective interventional study with detailed physiologic recordings in anesthetized, spontaneously breathing rats (n = 8). Animals breathing a normoxic gas mixture titrated to a partial arterial pressure of oxygen of 110-120 were exposed to an escalating dose of intravenous atropine (0.001, 0.01, 0.1, 5.0, and 20.0 mg/kg body mass). Arterial blood gas measurements were recorded every 2 min (×5) at baseline, and following each of the 5 doses of atropine. In addition, the animals regional pulmonary blood flow was measured using neutron-activated microspheres. Oxygenation decreased immediately following intravenous administration of atropine, despite a small increase in the volume of inspired air with no change in respiratory rate. Arterial blood gas analysis showed an increase in pulmonary dysfunction, characterized by a widening of the alveolar-arteriole gradient (p < 0.003 all groups except for the lowest dose of atropine). The microsphere data demonstrates an abrupt and marked heterogeneity of pulmonary blood flow following atropine treatment. In conclusion, atropine was found to decrease pulmonary gas exchange in a dose-dependent fashion in this rat model.

Central respiratory failure during acute organophosphate poisoning.

Organophosphate (OP) pesticide poisoning is a global health problem with over 250,000 deaths per year. OPs affect neuronal signaling through acetylcholine (Ach) neurotransmission via inhibition of acetylcholinesterase (AChE), leading to accumulation of Ach at the synaptic cleft and excessive stimulation at post-synaptic receptors. Mortality due to OP agents is attributed to respiratory dysfunction, including central apnea. Cholinergic circuits are integral to many aspects of the central control of respiration, however it is unclear which mechanisms predominate during acute OP intoxication. A more complete understanding of the cholinergic aspects of both respiratory control as well as neural modification of pulmonary function is needed to better understand OP-induced respiratory dysfunction. In this article, we review the physiologic mechanisms of acute OP exposure in the context of the known cholinergic contributions to the central control of respiration. We also discuss the potential central cholinergic contributions to the known peripheral physiologic effects of OP intoxication.

Dichlorvos exposure to the Kölliker-fuse nuclei is sufficient but not necessary for OP induced apnea.

Patients exposed to organophosphate (OP) compounds demonstrate a central apnea. The Kölliker-fuse nuclei (KF) are cholinergic nuclei in the brainstem involved in central respiratory control. We hypothesize that exposure of the KF is both necessary and sufficient for OP induced central apnea. We performed an animal study of acute OP exposure. Anesthetized and spontaneously breathing Wistar rats (n=24) were exposed to a lethal dose of dichlorvos using three experimental models. Experiment 1 (n=8) involved systemic OP poisoning using subcutaneous (SQ) 2,2-dichlorovinyl dimethyl phosphate (dichlorvos) at 100mg/kg or 3× LD50. Experiment 2 (n=8) involved isolated poisoning of the KF using stereotactic microinjections of dichlorvos (625µg in 50µl) into the KF. Experiment 3 (n=8) involved systemic OP poisoning with isolated protection of the KF using SQ dichlorvos (100mg/kg) and stereotactic microinjections of organophosphatase A (OpdA), an enzyme that degrades dichlorvos. Respiratory and cardiovascular parameters were recorded continuously. Animals were followed post exposure for 1h or until death. There was no difference in respiratory depression between animals with SQ dichlorvos and those with dichlorvos microinjected into the KF. Despite differences in amount of dichlorvos (100mg/kg vs. 1.8mg/kg) and method of exposure (SQ vs. CNS microinjection), 10min following dichlorvos both groups (SQ vs. microinjection respectively) demonstrated a similar percent decrease in respiratory rate (51.5 vs. 72.2), minute ventilation (49.2 vs. 68.8) and volume of expired gas (17.5 vs. 0.0). Animals with OpdA exposure to the KF during systemic OP exposure demonstrated less respiratory depression, compared to SQ dichlorvos alone (p<0.04). No animals with SQ dichlorvos survived past 25min post exposure, compared to 50% of animals with OpdA exposure to the KF. In conclusion, exposure of the KF is sufficient but not necessary for OP induced apnea. Protection of the KF during systemic OP exposure mitigates OP induced apnea.

Respiratory recovery following organophosphate poisoning in a rat model is suppressed by isolated hypoxia at the point of apnea.

Normal respiratory activity (eupnea) and gasping represent different types of respiratory activity, one of which is supported by oxygen (eupnea) and the other suppressed by oxygen (gasping). There is a loss of respiratory activity post-organophosphate (OP) poisoning that returns following treatment. It is not clear if post-OP respiratory activity represents eupnea or gasping. Depending on the type of respiratory activity, oxygenation during recovery from OP poisoning may have the potential to either support or suppress respiratory activity. We hypothesize that respiratory recovery following OP-induced central apnea represents a resumption of eupnea and is supported by oxygenation. We used an animal model of acute OP poisoning with detailed physiologic recordings. Animals were poisoned with dichlorvos and allowed to recover during a period of mechanical ventilation. Two experimental models were analyzed: (1) animals supported with 100% oxygen and (2) animals supported with a normoxic gas mixture titrated to a PaO(2) of 115 mmHg. Rats in this study demonstrated breathing that resumes spontaneously following OP-induced apnea with characteristics of both eupnea and gasping. The post-OP respiratory activity was suppressed by hypoxia, a characteristic of eupneic respiration and not gasping respiration. However, the respiratory rate during post-apneic breathing corresponded more closely to gasping. Analysis of phrenic nerve discharge activity was distinct from both eupnea and gasping, with peak inspiratory and post-inspiratory discharge activities significantly reduced compared to both eupnea and gasping. In summary, in this animal model post-apneic breathing distinct from eupnea and gasping that emerges following prolonged OP-induced central apnea is suppressed by hypoxia.

Dichlorvos-induced central apnea: effects of selective brainstem exposure in the rat.

The area of the brain responsible for organophosphate (OP)-induced central apnea is unknown. Automatic breathing is governed by circuits in the medulla and pons. Respiratory-related neurons in the brainstem are concentrated in a few areas, including ventral regions of the medulla, which contains a number of sites critical for respiratory rhythmogenesis, including the pre-Bötzinger complex (preBötC). The preBötC contains cholinergic receptors, making it a candidate site of action for the apnea-inducing effect of OP. We analyzed respiratory output during a series of experiments using both intact and reduced Wistar rat preparations exposed to dichlorvos (2,2-dichlorovinyl dimethyl phosphate). Exposure of the brainstem using a working heart-brainstem preparation resulted in a central apnea similar to that seen in intact animal models. In contrast, microdialysis of locally toxic doses of dichlorvos to the ventral region of the medulla resulted in delayed and mild respiratory depression in most animals and apnea in only 29% of the animals. We conclude that exposure of the entire brainstem to OP is sufficient to induce central apnea. Our microdialysis experiments suggest that the neural substrate for OP-induced central apnea involves a specific brainstem site other than the ventral region of the medulla, or apnea might result from a distributed effect involving cholinergic toxicities of multiple brainstem sites.

A randomized controlled trial of incision and drainage versus ultrasonographically guided needle aspiration for skin abscesses and the effect of methicillin-resistant Staphylococcus aureus.

STUDY OBJECTIVE: The incidence of skin and soft tissue infections has increased dramatically during the last decade, in part because of increased prevalence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Incision and drainage is considered the primary intervention; however, some clinicians prefer ultrasonographically guided needle aspiration because it represents a less invasive alternative. Our hypothesis is that ultrasonographically guided needle aspiration is equivalent to incision and drainage in treating simple skin and soft tissue abscesses. METHODS: This study was a nonblinded randomized controlled trial. Patients with uncomplicated superficial abscesses were randomized to incision and drainage with packing or ultrasonographically guided needle aspiration. Purulence obtained from the abscess was cultured to identify the causative organism. Bedside ultrasonography was performed pre- and postintervention to confirm the presence or absence of an abscess cavity. Patients were followed up at 48 hours (in person by a clinician) and on day 7 (telephone follow-up by research staff). The primary outcome was a combination of sonographic resolution and clinical resolution of the signs and symptoms of ongoing infection at day 7. The signs and symptoms of ongoing infection include increasing pain, erythema, and the presence of pus. Resolution was assessed with both sonographic resolution (day 0 and day 2) and improvement of clinical symptoms (day 2) and resolution of clinical symptoms (day 7) without further intervention. RESULTS: A total of 101 patients were enrolled, 54 incision and drainage and 47 ultrasonographically guided needle aspiration patients. At initial presentation, 60% (95% confidence interval [CI] 45% to 70%) of needle aspirations yielded little or no purulence, despite sonographic visualization of an abscess cavity and sonographic guidance during the procedure. The overall success of ultrasonographically guided needle aspiration was 26% (95% CI 18% to 44%) compared with 80% (95% CI 66% to 89%) success in patients randomized to incision and drainage. The difference between groups was 54% (95% CI 35% to 69%). Overall success of both incision and drainage and ultrasonographically guided needle aspiration was lower in patients with CA-MRSA. Patients with CA-MRSA (n=33) were less likely to receive successful drainage with needle aspiration (8% versus 55%) or incision and drainage (61% versus 89%). The difference for needle aspiration and incision and drainage was 47% (95% CI 15% to 57%) and 28% (95% CI 4% to 45%), respectively. CONCLUSION: Ultrasonographically guided needle aspiration is insufficient therapy for skin abscesses. The presence of CA-MRSA decreases the success of both incision and drainage and ultrasonographically guided needle aspiration.

Incidence of posterior vessel wall puncture during ultrasound-guided vessel cannulation in a simulated model.

OBJECTIVES: The incidence of posterior vessel wall puncture (PVWP) during central line placement with possible subsequent injury to structures lying behind the vein is unknown. At times the internal jugular vein lies immediately anterior to the carotid artery rather than lateral to it, leading to potential arterial puncture should the needle pass through the vein completely. The objective of this study is to evaluate the incidence of PVWP during simulated ultrasound (US)-guided vessel cannulation. METHODS: Enrolled subjects were emergency medicine resident and attending physicians. Subjects performed US-guided venous access on simulated blood vessels within gelatin-based US phantoms. While blinded to the purpose of the study, each subject performed successful cannulation of the vessel on separate phantoms, with wire placement confirmed by expert review of a follow-up US. Each phantom was subsequently deconstructed to manually inspect for PVWP. RESULTS: Thirty-five subjects with a range of experience in the technique participated, each performing both transverse and long-axis approaches for a total of 70 cannulations. The overall incidence of PVWP was 34% (95% confidence interval [CI] = 22.9% to 45.1%). CONCLUSIONS: This study found a high incidence of inadvertent PVWP during simulated US-guided vessel cannulation in this model.

Kinetics and efficacy of an organophosphorus hydrolase in a rodent model of methyl-parathion poisoning.

OBJECTIVES: Organophosphorus (OP) pesticides exert a tremendous health burden, particularly in the developing world. Limited resources, the severity of intentional OP ingestions, and a paucity of beneficial therapies all contribute to the morbidity and mortality of this broad class of chemicals. A novel theoretical treatment for OP poisoning is the use of an enzyme to degrade the parent OP in the circulation after poisoning. The aims of this study were to determine the pharmacokinetics and efficacy of an OP hydrolase (OpdA) in a rodent model of severe methyl-parathion poisoning. METHODS: Two animal models were used. First, Wistar rats were administered two different doses of the hydrolase (0.15 and 1.5 mg/kg), and the ex vivo hydrolytic activity of plasma was determined by a fluorometric method. Second, an oral methyl-parathion animal poisoning model was developed to mimic severe human poisoning, and the efficacy of postpoisoning OpdA (as measured by survival to 4 and 24 hours) was determined. RESULTS: The half-life of OpdA in the Wistar rat was dependent on the dose administered and ranged between 45.0 and 57.9 minutes. The poisoning model of three times the lethal dose to 50% of the population (3 x LD(50)) of methyl-parathion resulted in 88% lethality at 4 and 24 hours. Using a single dose of 0.15 mg/kg OpdA 10 minutes after poisoning resulted in 100% survival at 4 hours (p = 0.001 vs. placebo), but 0% at 24 hours postpoisoning (p = NS vs. placebo). CONCLUSIONS: The OP hydrolase OpdA exhibits pharmacokinetics suitable for repeated dosing and increases short-term survival after severe methyl-parathion poisoning.

Motivations, job procurement, and job satisfaction among current and former ultrasound fellows.

OBJECTIVES: Over the past decade, emergency medicine ultrasound (US) fellowships have proliferated, yet there are no published data describing employment trends among fellowship graduates. This study sought to assess factors motivating emergency physicians to pursue an US fellowship and to characterize their employment and job satisfaction after graduation. METHODS: An electronic survey was conducted of US fellows and graduates representing all 35 known fellowship programs. Non-responders were contacted at 2 weeks to encourage participation. Primary outcome measurements were the importance of factors motivating individuals to pursue an US fellowship (as rated on a numeric scale), job satisfaction among US fellowship graduates, the proportion of respondents practicing in academic versus community hospitals, clinical hours per week, and the rate of procurement of one's top choice of job after graduation. The chi-square test or Fisher's exact test was used for categorical variables, and the Mann-Whitney U-test was used to compare continuous variables between two groups. RESULTS: Of 170 invitations sent, 10 were undeliverable. The response rate was 61%; 74 graduates and 23 fellows completed the survey. Enhancing job opportunities, enjoyment of US, long-term job satisfaction and gaining skills not learned in residency rated highest as reasons for pursuing an US fellowship. Among graduates, 20% are satisfied with their current job, while 78% are very satisfied or extremely satisfied. Nearly one-third of graduates (31%) work primarily in non-academic hospitals, while only 9% of current fellows aspire to work in non-academic settings in the future. There was no difference in job satisfaction between academic- and community-based graduates. In comparison to those graduating in previous years, fellows graduating in 2008 were less likely to get their top job (97% vs. 75.0%, p = 0.018). CONCLUSIONS: Job satisfaction is high among US fellowship graduates and is unrelated to academic versus community affiliation. Three-fourths of recent graduates obtain their top choice of job upon completion of fellowship.

Respiratory failure induced by acute organophosphate poisoning in rats: effects of vagotomy.

Acute organophosphate (OP) poisoning causes respiratory failure through two mechanisms: central apnea and pulmonary dysfunction. The vagus nerve is involved in both the central control of respiratory rhythm as well as the control of pulmonary vasculature, airways and secretions. We used a rat model of acute OP poisoning with and without a surgical vagotomy to explore the role of the vagus in OP-induced respiratory failure. Dichlorvos (2,2-dichlorovinyl dimethyl phosphate) injection (100mg/kg subcutaneously, 3 x LD50) resulted in progressive hypoventilation and apnea in all animals, irrespective of whether or not the vagi were intact. However, vagotomized animals exhibited a more rapidly progressive decline in ventilation and oxygenation. Artificial mechanical ventilation initiated at onset of apnea resulted in improvement in oxygenation and arterial pressure in poisoned animals with no difference between vagus intact or vagotomized animals. Our observations suggest that vagal mechanisms have a beneficial effect during the poisoning process. We speculate that vagally mediated feedback signals from the lung to the brainstem serve as a modest protective mechanism against central respiratory depressive effects of the poison and that bulbar-generated efferent vagal signals do not cause sufficient pulmonary dysfunction to impair pulmonary gas exchange.