Emergency department initiated resuscitative endovascular balloon occlusion of the aorta (REBOA) for out-of-hospital cardiac arrest is feasible and associated with improvements in end-tidal carbon dioxide

Objectives

Out-of-hospital cardiac arrest (OHCA) claims the lives of approximately 350,000 people in the United States each year. Resuscitative endovascular balloon occlusion of the aorta (REBOA) when used as an adjunct to advanced cardiac life support may improve cardio-cerebral perfusion. Our primary research objective was to determine the feasibility of emergency department (ED)-initiated REBOA for OHCA patients in an academic urban ED.

Methods

This was a single-center, single-arm, early feasibility trial that used REBOA as an adjunct to advanced cardiac life support (ACLS) in OHCA. Subjects under 80 years with witnessed OHCA and who received cardiopulmonary rescuitation (CPR) within 6 minutes were eligible.

Results

Five patients were enrolled between February 2020 and April 2021. The procedure was successful in all patients and 4 of 5 (80%) patients had transient return of spontaneous circulation (ROSC) after aortic occlusion. Unfortunately, all patients re-arrested soon after intra-aortic balloon deflation and none survived to hospital admission. At 30 seconds post-aortic occlusion, investigators noted a statistically significant increase in end tidal carbon dioxide of 26% (95% confidence interval, 10%, 44%).

Conclusion

Initiating REBOA for OHCA patients in an academic urban ED setting is feasible. Aortic occlusion during chest compressions is temporally associated with improvements in end tidal carbon dioxide 30 seconds after aortic occlusion. Four of 5 patients achieved ROSC after aortic occlusion; however, deflation of the intra-aortic balloon quickly led to re-arrest and death in all patients. Future research should focus on the utilization of partial-REBOA to prevent re-arrest after ROSC, as well as the optimal way to incorporate this technique with other endovascular reperfusion strategies.

Resident Perceptions of a Publicly Disclosed Daily Productivity Dashboard

Introduction

Following resident requests, we created a public metrics dashboard to inform residents of their daily productivity. Our goal was to iteratively improve the dashboard based on resident feedback and to measure the impact of reviewing aggregate data on self-perceived productivity.

Methods

A 10-question anonymous survey was completed by our postgraduate year 1–3 residents. Residents answered questions on the dashboard and rated their own productivity before and after reviewing aggregate peer-comparison data. Using the Wilcoxon signed-rank test we calculated summary statistics for survey questions and compared distributions of pre- and post-test, self-rated productivity scores.

Results

All 43 eligible residents completed the survey (response rate 100%). Thirteen (30%) residents “rarely” or “never” reviewed the dashboard. No respondents felt the dashboard measured their productivity or quality of care “extremely accurately” or “very accurately.” Seven (16%) residents felt “very” or “extremely pressured” to change their practice patterns based on the metrics provided, and 28 (65%) would have preferred private over public feedback. Fifteen residents (35%) changed their self-perceived rank after viewing peer-comparison data, although not significantly in a particular direction (z = 0.71, P = 0.48).

Conclusion

Residents did not view the presented metrics as reflective of their productivity or quality of care. Viewing the dashboard did not lead to statistically significant changes in resident self-perception of productivity. This finding highlights the need for expanding the resident conversation and education on metrics, given their frequent inclusion in attending physician workforce payment and incentive models.

Research Protocol and Case Report of Emergency Department Endovascular Aortic Occlusion (REBOA) in Non-traumatic Cardiac Arrest

Background There are over 395,000 out-of-hospital cardiac arrests (OHCA) annually in the United States with an estimated 70-90% mortality rate and fewer than 10% surviving with a favorable neurologic outcome. Research in animal models and early human studies suggests that REBOA may play a role in augmenting coronary perfusion during OHCA by reducing blood flow to the lower body and re-directing it towards the heart and brain. We describe our initial case and research protocol to investigate the feasibility of REBOA in the emergency department (ED) for OHCA as an adjunct to ACLS. Methods We plan to enroll twenty patients in a single-arm interventional device study utilizing an exception from informed consent over a two-year period. The primary outcome is feasibility, with secondary outcomes assessing for hemodynamic changes pre- and post-aortic occlusion. Results Enrollment began in January 2020 and is ongoing. For the initial patient, an EP obtained ultrasound guided common femoral arterial access under chest compressions, followed by advancement of the REBOA catheter by an interventional radiologist. Immediately after aortic occlusion, investigators noted a substantial improvement in mean arterial pressure (MAP) (37 mmHg to 50 mmHg) and end tidal carbon dioxide (ETCO2) (33 mmHg to 50 mmHg), with transient but non-sustained return of spontaneous circulation (ROSC). Conclusion This is the first research protocol and case report of ED-REBOA initiation involving emergency physicians (EP) for non-traumatic OHCA. We describe our research protocol and initial case of a patient in OHCA who and underwent successful REBOA placement in the ED as an adjunct to ACLS.

STEMI Equivalents and Their Incidence during EMS Transport

Objective: The management of patients with ST-elevation myocardial infarction (STEMI) is time-critical, with a focus on early reperfusion to decrease morbidity and mortality. It is imperative that prehospital clinicians recognize STEMI early and initiate transport to hospitals capable of percutaneous coronary intervention (PCI) with a door-to-balloon time of ≤90 minutes. Three patterns have been identified as STEMI equivalents that also likely warrant prompt attention and potentially PCI: Wellens syndrome, De Winter T waves, and aVR ST elevation. The goal of our study was to assess the incidence of these findings in prehospital patients presenting with chest pain. Methods: We conducted a retrospective chart review from a large urban tertiary care emergency department. We reviewed the prehospital ECG, or ECG upon arrival, of 861 patients who were hospitalized and required cardiac catheterization between 4/10/18 and 5/7/19. Patients who had field catheterization lab activation by EMS for STEMI were excluded. If a prehospital ECG was not available for review, the first ECG obtained in the hospital was used as a proxy. Each ECG was screened for aVR elevation, De Winter T waves, and Wellens syndrome. Results: Of 278 charts with prehospital ECGs available, 12 met our criteria for STEMI equivalency (4.4%): 6 Wellens syndrome and 6 aVR STEMI. There were no cases of De Winters T waves. Of 573 charts with no prehospital ECG available, 27 had initial hospital ECGs that met our STEMI equivalent criteria (4.7%): 7 Wellens syndrome and 20 aVR STEMI. Again, there were no cases of De Winters T waves. Conclusions: These preliminary data suggest that there are significant numbers of patients whose prehospital ECG findings do not currently meet criteria for field activation of the cardiac catheterization lab, but who may require prompt catheterization. Further studies are needed to look at outcomes, but these results could support the need for further education of prehospital clinicians regarding recognition of these STEMI equivalents, as well as quality initiatives aimed at decreasing door-to-balloon time for patients with STEMI equivalents.

Implementation of a Physician Assistant Emergency Medicine Residency Within a Physician Residency

Physician assistants (PA) are an important part of emergency department healthcare delivery and are increasingly seeking specialty-specific postgraduate training. Our goal was to pilot the implementation of a PA postgraduate program within an existing physician residency program and produce emergency medicine-PA (EM-PA) graduates of comparable skill to their physician counterparts who have received the equivalent length of EM residency training to date (evaluated at the end of first year of EM training).

The curriculum was based on the Society for Emergency Medicine Physician Assistants (SEMPA) recommendations with a special focus on side-by-side training with EM resident physicians. In reviewing the program, the authors examined faculty evaluations, as well as procedure and ultrasound experience that the trainees received. We found comparable evaluations between first-year EM-PA and physician trainee cohorts. This program serves as a pilot study to demonstrate the feasibility of collocating clinical and didactic programming for physicians and EM-PAs during their postgraduate training. This brief innovation report outlines the logistics of the clinical and didactic curriculum and provides a summary of outcomes evaluated.

Research Protocol and Case Report of Emergency Department Endovascular Aortic Occlusion (REBOA) in Non-traumatic Cardiac Arrest

Background There are over 395,000 out-of-hospital cardiac arrests (OHCA) annually in the United States with an estimated 70-90% mortality rate and fewer than 10% surviving with a favorable neurologic outcome. Research in animal models and early human studies suggests that REBOA may play a role in augmenting coronary perfusion during OHCA by reducing blood flow to the lower body and re-directing it towards the heart and brain. We describe our initial case and research protocol to investigate the feasibility of REBOA in the emergency department (ED) for OHCA as an adjunct to ACLS. Methods We plan to enroll twenty patients in a single-arm interventional device study utilizing an exception from informed consent over a two-year period. The primary outcome is feasibility, with secondary outcomes assessing for hemodynamic changes pre- and post-aortic occlusion. Results Enrollment began in January 2020 and is ongoing. For the initial patient, an EP obtained ultrasound guided common femoral arterial access under chest compressions, followed by advancement of the REBOA catheter by an interventional radiologist. Immediately after aortic occlusion, investigators noted a substantial improvement in mean arterial pressure (MAP) (37 mmHg to 50 mmHg) and end tidal carbon dioxide (ETCO2) (33 mmHg to 50 mmHg), with transient but non-sustained return of spontaneous circulation (ROSC). Conclusion This is the first research protocol and case report of ED-REBOA initiation involving emergency physicians (EP) for non-traumatic OHCA. We describe our research protocol and initial case of a patient in OHCA who and underwent successful REBOA placement in the ED as an adjunct to ACLS.

Accelerated surgery versus standard care in hip fracture (HIP ATTACK): an international, randomised, controlled trial

BACKGROUND

Observational studies have suggested that accelerated surgery is associated with improved outcomes in patients with a hip fracture. The HIP ATTACK trial assessed whether accelerated surgery could reduce mortality and major complications.

METHODS

HIP ATTACK was an international, randomised, controlled trial done at 69 hospitals in 17 countries. Patients with a hip fracture that required surgery and were aged 45 years or older were eligible. Research personnel randomly assigned patients (1:1) through a central computerised randomisation system using randomly varying block sizes to either accelerated surgery (goal of surgery within 6 h of diagnosis) or standard care. The coprimary outcomes were mortality and a composite of major complications (ie, mortality and non-fatal myocardial infarction, stroke, venous thromboembolism, sepsis, pneumonia, life-threatening bleeding, and major bleeding) at 90 days after randomisation. Patients, health-care providers, and study staff were aware of treatment assignment, but outcome adjudicators were masked to treatment allocation. Patients were analysed according to the intention-to-treat principle. This study is registered at ClinicalTrials.gov (NCT02027896).

FINDINGS

Between March 14, 2014, and May 24, 2019, 27 701 patients were screened, of whom 7780 were eligible. 2970 of these were enrolled and randomly assigned to receive accelerated surgery (n=1487) or standard care (n=1483). The median time from hip fracture diagnosis to surgery was 6 h (IQR 4-9) in the accelerated-surgery group and 24 h (10-42) in the standard-care group (p<0·0001). 140 (9%) patients assigned to accelerated surgery and 154 (10%) assigned to standard care died, with a hazard ratio (HR) of 0·91 (95% CI 0·72 to 1·14) and absolute risk reduction (ARR) of 1% (-1 to 3; p=0·40). Major complications occurred in 321 (22%) patients assigned to accelerated surgery and 331 (22%) assigned to standard care, with an HR of 0·97 (0·83 to 1·13) and an ARR of 1% (-2 to 4; p=0·71).

INTERPRETATION

Among patients with a hip fracture, accelerated surgery did not significantly lower the risk of mortality or a composite of major complications compared with standard care.

FUNDING

Canadian Institutes of Health Research.

Successful Implementation of a Resident Liaison to Medical Students in Emergency Medicine Rotations

BACKGROUND

As the role of the resident-as-teacher grows, some residents are inspired to develop themselves early as leaders in education while in training. We describe the successful implementation of a resident liaison (RL) to medical students in emergency medicine (EM) as a way to develop resident leaders in medical education.

METHODS

This position was implemented to develop interested residents as leaders in medical education and to provide medical students access to an EM physician who is closer to their training level and may be more approachable than the clerkship director. RLs are mentored by the clerkship director and are involved in curricular programming and education research.

RESULTS

This innovation has strengthened our student EM rotations and has provided residents with a unique opportunity to explore a career in medical education. Residents have made tangible contributions to our educational programming in this role and have pursued careers in medical education. The program has been recognized as a "best practice" by students and the school of medicine.

CONCLUSIONS

The RL initiative has conferred significant benefits to residents and medical students. Implementation of a RL program may benefit EM rotations outside of our institution and perhaps outside of the EM specialty.

Heterotopic Ossification in Hip Arthroscopy: an Updated Review

PURPOSE OF REVIEW

Heterotopic ossification (HO) in hip arthroscopy is a common post-operative complication. This review was undertaken to provide an update (2014 present) on the current literature regarding HO in hip arthroscopy.

RECENT FINDINGS

Risk factors for HO post-hip arthroscopy include male gender, mixed impingement, picture, and the size of CAM resection. HO prophylaxis with NSAIDs has been proven to decrease the rate of HO post-hip arthroscopy; however, there is inherent risk to long-standing NSAIDs therapy. HO post-hip arthroscopy is not uncommon as a radiological finding, but symptomatic HO post-hip arthroscopy requiring revision surgery is a rare event, at < 1%. The outcomes for revision surgery for HO excision have fair outcomes. The hip arthroscopist should stratify their patients based on known risk factors, and determine whether NSAIDs prophylaxis is warranted.

Spontaneous Bilateral Femoral Fractures After High-Dose Zoledronic Acid

The authors report a case of spontaneous bilateral diaphyseal femoral fractures believed to be caused by oversuppression of bone remodeling as a result of long-term, high-dose treatment with bisphosphonate. The patient reported pain in both thighs before the fractures. Typical pathologic changes appeared on both femoral radiograph and bone scan before the fractures. Several hours after admission to the emergency department of the authors' institution, the patient underwent closed reduction and internal fixation with intramedullary nails for the bilateral femoral diaphyseal fractures. Treatment with zoledronic acid was immediately discontinued. In recent years, low-energy femoral diaphyseal fractures in patients undergoing long-term bisphosphonate treatment have been reported. It is believed that the prolonged treatment causes long-term suppression of bone remodeling and accumulation of microdamage. It is important to observe patients who are undergoing bisphosphonate treatment carefully. In this case study, the authors report the patient's unique medical history.

Pigeons flexibly time or count on cue

In Experiment 1, pigeons were presented with a sequence of light flashes and cued to peck a key for reward either after a fixed time or after a fixed number of flashes. Curves that showed the rate of key pecking over time within trials indicated that peak rates of response were reached near the fixed time on timing-cued trials and near the fixed number of flashes on counting-cued trials. In Experiment 2, the key cue was shifted from timing to counting or from counting to timing midway through a trial. The peak times reached after the cue change indicated that pigeons kept track of time while cued to count but did not count while cued to time. These findings suggest a basic asymmetry in the dual-mode model of timing and counting.

Borrelia burgdorferi escape mutants that survive in the presence of antiserum to the OspA vaccine are killed when complement is also present

As an initial attempt to investigate the possible role of outer surface protein A (OspA) escape mutants of Borrelia burgdorferi in decreasing the efficacy of the OspA vaccine, mutants of the HB19 strain of B. burgdorferi sensu stricto were selected in vitro from an uncloned, low-passage-number isolate. The antiserum used for selection was obtained from rhesus monkeys that had been given a vaccine of the same formulation and dose, and by the same route of administration, as that given to humans in several trials. All of the mutants selected in liquid medium and subsequently cloned twice in solid medium expressed a single abundant protein of 28 to 34 kDa instead of both OspA and OspB. Depending on the mutant, this protein reacted strongly, weakly, or not detectably with the anti-OspA antibody used for selection. Analysis of the ospAB locus of each of four representatives from these three groups of mutants by PCR with oligonucleotide primers that hybridize to flanking regions of the ospAB operon, and of the corresponding phenotype with monoclonal antibodies that bind to the amino or carboxyl terminus of the OspA or OspB polypeptide, indicated that in all cases a deletion within the operon had occurred. Spirochetes from the four mutant strains chosen for further analysis could be killed in antibody-dependent, complement-mediated killing assays with the selecting anti-OspA antibody, despite their resistance to killing with this antibody in the absence of complement. Complement-mediated killing occurred at an antibody concentration higher than that required to kill wild-type spirochetes. If anti-OspA antibody acts only within the tick, where complement is probably ineffective due to tick-derived decomplementing factors, then OspA escape mutants, if infectious, could seriously diminish the efficacy of OspA vaccines. On the other hand, if the killing of B. burgdorferi with anti-OspA antibody also takes place within the human host, then our results indicate that chimeric/deletion escape mutants will be killed as well.

Effect of conjugation methodology, carrier protein, and adjuvants on the immune response to Staphylococcus aureus capsular polysaccharides

Conjugate vaccines were prepared with S. aureus type 8 capsular polysaccharide (CP) using three carrier proteins: Pseudomonas aeruginosa exotoxin A (ETA), a non-toxic recombinant ETA (rEPA), and diphtheria toxoid (DTd). Adipic acid dihydrazide (ADH) or N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) was used as a spacer to link the CP to carrier protein. All conjugates gave a high immune response with a boost after the second immunization. Conjugates prepared with ADH gave higher antibody titers than conjugates prepared with SPDP. IgG1 was the primary subclass elicited by all conjugates regardless of the carrier protein or the conjugation method used to prepare the vaccines. The non-immunogenic CP and the conjugates were formulated with either monophosphoryl lipid A (MPL), QS21, or in Novasomes and evaluated in mice. While the adjuvants failed to improve the immunogenicity of the nonconjugated CP, a more than fivefold increase in the antibody levels was observed when these adjuvants were used with the conjugates. Significant rises in IgG2b and IgG3 were observed with all formulations. The enhancement of the immunogenicity and the IgG subclass shift, as seen with some adjuvants, may prove to be important in immunocompromised patients.

Human immunodeficiency virus 1-specific IgA capture enzyme immunoassay for early diagnosis of human immunodeficiency virus 1 infection in infants. NYC Perinatal HIV Transmission Study Group

A simplified human immunodeficiency virus 1 (HIV-1)-specific IgA capture enzyme immunoassay (IgA-CEIA) was evaluated and compared with IgA-Western blot assay for early diagnosis of HIV-1 infection in infants born to seropositive women. A total of 232 coded sera collected prospectively from 70 infants were tested. All 25 sera from 10 HIV-1-negative infants born to seronegative mothers (negative controls) were negative by both assays. All 111 sera from 37 seroreverting, uninfected infants were negative by IgA-CEIA (specificity, 100%), whereas 110 of 111 sera were negative by IgA-Western blot assay (specificity, > 99%). Overall IgA-CEIA detected HIV-IgA in 20 (87%) of 23 infected infants, and IgA-Western blot assay detected HIV-IgA in 21 (91.3%) of 23 infants; specimen-wise agreement between the 2 assays was > 80%. Analysis of results by age group indicated that after 2 months of age both assays were equivalent with sensitivity ranging from 60 to 80%. Quantitative data provided by IgA-CEIA suggests that the bulk of HIV-1 IgA synthesis in most HIV-1-infected infants occurs after 2 months of age.

Dynamics of maternal IgG antibody decay and HIV-specific antibody synthesis in infants born to seropositive mothers. The NYC Perinatal HIV Transmission Study Group

We have used a human immunodeficiency virus type 1 (HIV-1)-specific IgG-Fc capture enzyme immunoassay (IgG-CEIA) to elucidate the dynamics of HIV-1 maternal antibody decay and de novo synthesis of HIV-1 antibodies in infants. Two hundred and thirty-nine serum specimens from 77 infants were analyzed by the IgG-CEIA and by two different conventional EIAs. With the IgG-CEIA, IgG was captured by an anti-human IgG monoclonal antibody (3C8) that reacts with all subclasses and was detected by recombinant HIV-1 envelope protein (CBre3)-peroxidase conjugate. Unlike the conventional EIAs, the IgG-CEIA showed a rapid decay of HIV-1-specific antibody in uninfected infants, with decline to background levels by 6 months (T1/2 [half-life] = 28-30 days). All 69 specimens collected from 39 uninfected infants between 6 and 15 months of age were negative by IgG-CEIA. However, HIV-1 antibodies remained high in infected infants; 20/22 infants (90.9%) with specimens between the ages of 6 to 23 months were positive by IgG-CEIA. Subtracting mean IgG-CEIA optical density values of seroreverting infants from those of HIV-1-infected infants in corresponding age groups provided a model for seroconversion in infected infants, with detectable IgG antibody synthesis starting about 3 months after birth. The IgG-CEIA may be a simple and important tool for early diagnosis of HIV-1 infection in infants at 6 months of age.

A thermodynamic and electron paramagnetic resonance study of structural changes in calmodulin induced by aluminum binding

Bovine brain calmodulin binds 3 mol aluminum per mol protein with dissociation constants in range of 10(-7) to 10(-6) molar. EPR spectra of spin-labelled calmodulin provide data indicating that aluminum binding causes decreased probe immobilization as compared to the effects of calcium binding. This result of aluminum binding indicates that A1-calmodulin is a more random, open polypeptide relative to the structure of Ca2+-calmodulin. Calorimetric measurements of aluminum binding provide data showing that the first mol of aluminum bound is accompanied by the largest enthalpic change (-3.9 kcal mol-1), whereas binding of the second and third mol of aluminum are each entropically driven.