Faculty Bibliography

OBJECTIVE: Our objective was to determine whether organized or disorganized cardiac activity is associated with increased survival in patients who present in pulseless electrical activity (PEA) treated with either 1) standard advanced cardiac life support (ACLS) medications or 2) other interventions. METHODS: This was a secondary analysis of a prospective, multi-center observational study utilizing ultrasound in out-of-hospital or inemergency department PEA arrest. Bedside ultrasound was performed as ACLS protocol started and during pulse checks. Only cases with visible cardiac activity on ultrasound were included in the present analysis. Cardiac activity was categorized as disorganized (agonal twitching) or organized (contractions with changes in ventricular dimensions). Patients were categorized as receiving either standard bolus ACLS medications or alternative medications during the resuscitation (continuous adrenergic agents, thrombolytics, others). The primary outcome was survival to hospital admission. The secondary outcome was return of spontaneous circulation (ROSC). Multivariate modeling was performed to assess association between survival to hospital admission in patients with intravenous adrenergic agents and cardiac activity. RESULTS: In our cohort of 225 patients in PEA cardiac arrest with cardiac activity on ultrasound, the overall survival rate was higher in patients with organized cardiac activity than with disorganized cardiac activity. PEA cardiac arrest patients with organized cardiac activity treated with standard ACLS interventions demonstrated improved survival to hospital admission compared to those with disorganized activity (37.7% (95%CI 24.8-50.2%) versus 17.9% (95%CI 10.9-28%). PEA cardiac arrest patients with organized cardiac activity who received continuous adrenergic agents during the resuscitation and prior to ROSC demonstrated higher survival to hospital admission 45.5% (95%CI 26.9-65.4%) and ROSC 90.9% (95%CI 71.0-98.7%) compared to those with disorganized cardiac activity who received continuous adrenergic agents during the resuscitation 0% (95%CI 0-23.0%) and 47.1% (95%CI 26-69%). Regression analysis demonstrates an association between increased survival in patients receiving intravenous adrenergic agents and organized cardiac activity. CONCLUSION: Survival in patients following PEA arrest is higher in patients with organized cardiac activity. The initiation of continuous adrenergic agents during PEA was associated with improved survival to hospital admission in patients with organized cardiac activity on bedside ultrasound, but this improvement was not seen in patients in PEA with disorganized cardiac activity. Bedside ultrasound may identify a subset of patients that respond differently to ACLS interventions.

BACKGROUND: Point-of-care ultrasound has been suggested to improve outcomes from advanced cardiac life support (ACLS), but no large studies have explored how it should be incorporated into ACLS. Our aim was to determine whether cardiac activity on ultrasound during ACLS is associated with improved survival. METHODS: We conducted a non-randomized, prospective, protocol-driven observational study at 20 hospitals across United States and Canada. Patients presenting with out-of-hospital arrest or in-ED arrest with pulseless electrical activity or asystole were included. An ultrasound was performed at the beginning and end of ACLS. The primary outcome was survival to hospital admission. Secondary outcomes included survival to hospital discharge and return of spontaneous circulation. FINDINGS: 793 patients were enrolled, 208 (26.2%) survived the initial resuscitation, 114 (14.4%) survived to hospital admission, and 13 (1.6%) survived to hospital discharge. Cardiac activity on US was the variable most associated with survival at all time points. On multivariate regression modeling, cardiac activity was associated with increased survival to hospital admission (OR 3.6, 2.2-5.9) and hospital discharge (OR 5.7, 1.5-21.9). No cardiac activity on US was associated with non-survival, but 0.6% (95% CI 0.3-2.3) survived to discharge. Ultrasound identified findings that responded to non-ACLS interventions. Patients with pericardial effusion and pericardiocentesis demonstrated higher survival rates (15.4%) compared to all others (1.3%). CONCLUSION: Cardiac activity on ultrasound was the variable most associated with survival following cardiac arrest. Ultrasound during cardiac arrest identifies interventions outside of the standard ACLS algorithm.

Background: Previous studies suggest that no cardiac activity visualized by U/S during Advanced Cardiac Life Support (ACLS) predicts death. However, the evidence supporting this arises from small, single center retrospective studies. Objectives: The purpose of this study was to examine whether cardiac activity during ACLS is a associated with improved outcomes in a prospective multi-center study. Methods: Eighteen sites across North America collected prospective cardiac US data on patients with pulseless electrical activity (PEA) or asystole during resuscitation following ACLS protocols. An initial US was performed as ACLS started and again at the conclusion of the resuscitation efforts. US images were interpreted unblinded as demonstrating cardiac activity or not. The primary outcome was survival to hospital admission. The secondary outcome was return of spontaneous circulation (ROSC). All data were uploaded into a central electronic database (REDCap). Based on prior studies, our initial power calculation determined 761 patients were required assuming 20% ROSC and a misclassification rate of 1%. Comparisons were performed using Mann-Whitney U test and Fisher's exact test. Results: A total of 1103 patients presenting from May 2011 to November 2014 were included. Of these, 288 were excluded due to (Figure presented) missing data or breach in protocol, leaving 815 patients. The initial presenting cardiac rhythm was PEA (49%) and asystole (48%). Figure 78 depicts median times (IQR) of resuscitation events in all patients. Patients without cardiac activity at initial ED US had longer downtimes in the field prior to EMS arrival (7 min vs 4 min, p <0.0001). Patients with cardiac activity on the initial US underwent more resuscitation time in the ED (22 vs 16min, p<0.001). The presence of cardiac activity on initial US was associated with greater incidence of ROSC (49.4 vs 14.0%, p<0.001) and survival to admission (30.3 vs 8.8%, p<0.001). Asystolic patients demonstrated no statistical difference in ROSC relative to the presence or absence of cardiac activity on US (9.8 vs 18.4%, p=0.15), but patients with PEA did (21.2 vs 53.3%, p<0.001). Conclusion: Patients in PEA and asystole with no cardiac activity on initial US during CPR can survive to hospital admission, but the survival rate is more than three times greater in patients with detectable cardiac activity on initial US

Background: Lower extremity compression ultrasound (US) for deep venous thrombosis (DVT) assessment by emergency physicians varies in technique and accuracy across published reports. This stems from differences in experience and training as well as paucity of data describing the minimal components needed to perform an accurate exam. Furthermore, no data exists describing emergency physician agreement during formal DVT ultrasound reviews. Emergency physician reviewer agreement is critical to developing a universal, standardized, and accurate approach to lower extremity compression US in the emergency department (ED). Study Objectives: This study evaluates agreement between expert sonographer reviewers in each component of the lower extremity compression US performed at our institution. We hypothesized emergency physician expert reviewers will strongly agree on all components of the review process. Methods: This is a prospective, observational study of ED patients at an urban, academic ED. Adult patients receiving an ED lower extremity compression ultrasound for DVT assessment prior to any other imaging study for DVT assessment were eligible. Enrollment was based on a convenience sample. Lower extremity compression US was performed by the treating physician per our departmental standard method: incremental compression and evaluation for complete coaptation of deep veins are performed from the common femoral vein and saphenous vein junction terminating ten centimeters distal over thigh, and again starting at the popliteal vein (PV) and terminating at the PV trifurcation. Data to calculate a Wells DVT score was also collected. ED lower extremity compression US studies were later evaluated by two of three expert ultrasound reviewers using a checklist of predetermined critical components (Table 1). These components were based on a literature review of exam elements thought to be valuable for DVT assessment and are included in our standard review process. Each category was judged as either present or !

BACKGROUND: Traumatic knee pain is a common complaint in the emergency department (ED). Conventional radiographs are often ordered as the initial screening study, but might not be readily available or always identify significant fractures. Ultrasonography has been shown to be useful in the evaluation of knee fractures not identified by radiography. OBJECTIVES: To discuss and briefly review the literature regarding the use of suprapatellar bursal ultrasonography to detect lipohemarthrosis (LH) as a surrogate marker for an intraarticular knee fracture. CASE REPORT: A 37-year-old man presented to the ED after a traumatic knee injury. Bedside ultrasonography demonstrated the characteristic triple layer sign of LH, raising the suspicion for an intraarticular fracture. The diagnosis was later confirmed with radiography and computed tomography (CT). CONCLUSIONS: The sonographic finding of LH may be used as a sensitive surrogate marker for intraarticular knee fracture in the ED. Ultrasound can be considered as an adjunct modality in ED patients with suspicion for fracture and negative knee radiographs.

OBJECTIVES: Sonographic visualization of an empty esophagus to confirm endotracheal tube placement during intubation may be more reliable than identifying an endotracheal tube within the trachea. Our objective was to determine the frequency in which the normal empty esophagus can be identified at or below the level of the cricoid ring in children. METHODS: A prospective cohort of children and young adults presenting to the emergency department were examined by sonography to determine the dynamic anatomic relationship of the trachea and esophagus at or below the level of the cricoid ring. For children with the esophagus behind or partially behind the trachea, cricoid pressure was applied using a linear array transducer to visualize the presence of lateral sliding of the esophagus from behind the trachea. RESULTS: A total of 55 patients 21 years or younger were examined; 51% (28) were male. Sixty-two percent (34) had esophagi positioned partially to the left of the cricoid ring, 20% (11) completely to the left of the cricoid ring, 16% (9) behind the cricoid ring, and 2% (1) partially to the right of the cricoid ring. When cricoid pressure was applied using the ultrasound transducer, the esophagus was visualized lateral to the trachea in all patients (54 to the left and 1 to the right; n = 55 of 55; 95% confidence interval, 94%-100%). CONCLUSIONS: With cricoid pressure applied using a linear transducer, the esophagus was visualized lateral to the trachea in all children and young adults. Visualizing an empty esophagus by point-of-care sonography may be feasible to confirm endotracheal tube placement by a process of elimination.

Background: Management of upper extremity injuries using ultrasound-guided (UG) supraclavicular brachial plexus (SCBP) nerve blocks is described in the emergency medicine literature. UG SCBP blocks are fast, safe, and effective, and avoid certain risks inherent in procedural sedation. UG SCBP blocks are performed by experienced physician sonographers. Objectives: To determine the training needed to acquire and interpret SCBP sonographic images, a necessary first step in the performance of SCBP blocks. Methods: Six medical students, with no ultrasound experience, participated in the study. Didactic education was provided via two one-hour instructional sessions: students reviewed ultrasound (US) machine use, US scanning techniques, and US anatomy of the SCBP. Two videos of patients receiving SCBP blocks were also viewed. After initial didactic education, students trained in the emergency department, performing US of the SCBP on 50-70 patients. During clinical training, brief review of student's SCBP US images (every 10-15 patients) was given. On completion of clinical training, students independently recorded US images of SCBP anatomy on 43-116 patients with no oversight. Students labeled relevant structures of each SCBP image. Gel-to-image times and anticipated scan difficulty (Likert scale) were recorded. An experienced, RDMS-certified emergency physician skilled in the performance of SCBP blocks reviewed all images and determined if the image quality was acceptable for performing a SCBP nerve block. A kappa calculation is pending image review by another expert physician in UG SCBP blocks. Results: 469 SCBP images were collected. 95% (447) [95% CI 93-96.9%] were found to be accurate and an acceptable starting point for ultrasound-guided SCBP blocks. The range of accuracy for each of the six students was 92.5%- 97.8%. The average gel-to- image time among all students was 42 seconds (standard deviation = 52 sec). No association was found between the student's anticipated level of difficulty and the ability to acquire an acceptable image or identify relevant landmarks. Conclusion: Novice sonographers with no prior US experience can acquire accurate SCBP images (with relevant landmarks) needed for the SCBP block following limited training. Subjective perceptions of anticipated sonographic difficulty were not associated with the rate of performing an acceptable US image

BACKGROUND: In adequately resourced clinical environments, diagnosis of hypoxemia via pulse oximetry is routine. Unfortunately, pulse oximetry is rarely utilized in under-resourced hospitals in developing countries. AIM: The prevalence of undiagnosed hypoxemia among adults and children with illnesses other than pneumonia in these environments remains poorly described. METHODS: This cross-sectional analysis of the prevalence of hypoxemia was conducted in Kapiri Mposhi, Zambia, at the 60-bed District Hospital, which serves a population of 320,000. The resting room air oxygen saturations of two consecutive samples of all adult and pediatric inpatients were measured in December 2008 and March 2009 using handheld pulse oximetry. Hypoxemia was defined as resting room air SpO(2) less than 90%. RESULTS: A total of 192 patients were enrolled: 68 young children (<5 years old), 15 older children (5-17 years old), and 109 adults (>/=18 years old). Five young children (7%), 0 older children (0%), and 10 adults (9%) were hypoxemic. No hypoxemic patients were receiving oxygen therapy at the time of diagnosis. Pneumonia, tuberculosis, and malnutrition were the most common conditions among those with hypoxemia. Oximetry data changed clinical management in all observed cases of hypoxemia and several cases of normoxemia, leading to application of supplemental oxygen, initiation of further diagnostic testing, prolongation of inpatient stay, or expedited discharge home. CONCLUSIONS: Undiagnosed hypoxemia is present among inpatients at this district hospital in rural Zambia with high prevalence in both adults and young children. These results support routine screening for hypoxemia in similar facilities in both age groups. Further investigation is warranted into the clinical impact and cost-effectiveness of pulse oximetry, provision of oxygen concentrators, and training on their use in developing countries