Novel Use of a Gas Analyzer Can Reliably Predict the Arterial Oxygen among Emergency Department Patients Undergoing Rapid Sequence Intubation.

BACKGROUND: To our knowledge, no study has assessed the correlation of fraction of inspired oxygen (FiO2) and end-tidal oxygen (EtO2) values obtained from a gas analyzer during the preoxygenation period of rapid sequence intubation (RSI) to predict partial pressure of oxygen (PaO2) among patients requiring intubation in the emergency department (ED). OBJECTIVE: The purpose of this study was to determine whether a simple equation using EtO2 and FiO2 at time of induction could reliably estimate minimal PaO2 in ED patients undergoing RSI. METHODS: We conducted an observational pilot study performed in an adult ED utilizing a gas analyzer to obtain EtO2 and FiO2 values in ED patients undergoing RSI from data collectors blinded to our objective. The Pearson correlation coefficient was calculated between the equation's predicted PaO2 and the PaO2 drawn from an arterial blood gas shortly after intubation. A Bland-Altman plot analysis was performed to identify any additional bias. RESULTS: Seventy-five patients were enrolled. The equation's mean predicted minimal PaO2 and mean PaO2 from an arterial blood gas within 3 min after intubation was 178 mm Hg (95% confidence interval [CI] 145-211 mm Hg) and 209 mm Hg (95% CI 170-258 mm Hg), respectively. The Pearson correlation coefficient between the predicted minimal PaO2 and post-intubation PaO2 demonstrated a strong correlation (r2 = 0.89). The Bland-Altman plot indicated no bias affecting the correlation between the predicted and actual PaO2. CONCLUSIONS: Among ED patients undergoing RSI, the use of a gas analyzer to measure EtO2 and FiO2 can provide a reliable measure of the minimal PaO2 at the time of induction during the RSI phase of preoxygenation.

Use of End Tidal Oxygen Monitoring to Assess Preoxygenation During Rapid Sequence Intubation in the Emergency Department.

STUDY OBJECTIVE: Preoxygenation is important to prevent oxygen desaturation during emergency airway management. The purpose of this study is to describe the use of end tidal oxygen (eto2) during rapid sequence intubation in the emergency department. METHODS: This study was carried out in 2 academic centers in Sydney, Australia, and New York City. We included patients undergoing rapid sequence intubation in the emergency department. A standard gas analyzer was used to measure eto2. Preoxygenation methods included nonrebreather mask and bag-valve-mask ventilation. We measured eto2 before preoxygenation and at administration of rapid sequence intubation medications. We also characterized peri-intubation SpO2, identifying instances of SpO2 less than 90%. RESULTS: We included 100 patients during a 6-month period. Median eto2 level before and after preoxygenation was 53% (interquartile range [IQR] 43% to 65%) and 78% (IQR 64% to 86%), respectively. One fourth of patients achieved an eto2 level greater than 85%. Median eto2 level achieved varied with preoxygenation method, ranging from 80% (IQR 60% to 87%) for the nonrebreather mask group to 77% (IQR 65% to 86%) for the bag-valve-mask group. The method with the highest median eto2 level was nonrebreather mask at flush rate (86%; IQR 80% to 90%) and the lowest median eto2 level was nonrebreather mask at 15 L/min (57%; IQR 53% to 60%). Eighteen patients (18%) experienced oxygen desaturation (SpO2 <90%); of these, 14 (78%) did not reach an eto2 level greater than 85% at induction. CONCLUSION: ETO2 varied with different preoxygenation techniques employed in the emergency department. Most patients undergoing rapid sequence intubation did not achieve maximal preoxygenation. Measuring ETO2 in the emergency department may be a valuable adjunct for optimizing preoxygenation during emergency airway management.

Respiratory adjusted shock index for identifying occult shock and level of Care in Sepsis Patients.

OBJECTIVE: Early identification of shock allows for timely resuscitation. Previous studies note the utility of bedside calculations such as the shock index (SI) and quick sepsis-related organ failure assessment (qSOFA) to detect occult shock. Respiratory rate may also be an important marker of occult shock. The goal of our study was to evaluate whether using a modified SI with respiratory rate would improve identification of emergency department sepsis patients admitted to an ICU or stepdown unit. METHODS: A prospective, observational cohort study of the respiratory adjusted shock index (RASI), defined as HR/SBP × RR/10, was conducted. RASI was calculated from triage vital signs and compared to serum lactate. Primary outcome was admission to a higher level of care defined as ICU or stepdown unit. A multivariable logistic regression model including RASI, SI, lactate, age and sex was performed with disposition as the outcome variable. Areas under the curve (AUC) were calculated to detect occult shock and level of care for RASI, SI, and qSOFA. RESULTS: 408 patients were enrolled, 360 were included in the analysis. Regression analysis revealed that lactate (OR 1.55, z = 4.38, p < 0.0001) and RASI (OR 2.27, z = 3.03, p < 0.002) were predictive of need for higher level of care. The AUC for RASI, SI, and qSOFA to detect occult shock were 0.71, 0.6, and 0.61 respectively. RASI also had a significant AUC in predicting level of care at 0.75 compared to SI (0.64) and qSOFA (0.62). CONCLUSIONS: RASI may have utility as a rapid bedside tool for predicting critical illness in sepsis patients.

Peri-intubation factors affecting emergency physician choice of paralytic agent for rapid sequence intubation of trauma patients.

INTRODUCTION: No study has assessed predictors of physician choice between the succinylcholine (Succ) and rocuronium (Roc) for rapid sequence intubation (RSI) during the initial resuscitation of trauma patients in the emergency department (ED). METHODS: We retrospectively evaluated of the use of Succ and Roc for adult trauma patients undergoing RSI at a Level 1 trauma center. The primary outcome was to identify factors affecting physician choice of paralytic agent for RSI analyzed by cluster analysis using pre-intubation vital signs and early mortality. The secondary outcome was to identify factors influencing physician choice of paralytic agent using a logistic regression model reported as adjusted odds ratios (aOR). RESULTS: The analysis included 215 patients, including 148 receiving Succ and 67 receiving Roc. The two groups were similar in regard to age, provider level of training, mean GCS (10 vs. 10) and median ISS (27 vs. 27). Cluster analysis using peri-intubation patient vital signs and early mortality indicates that patients with predominantly abnormal vital signs and early mortality were more likely to receive Roc (74%) than those without abnormal vital signs prior to intubation or early mortality (24%). Hypoxemia prior to RSI (aOR 12.3 [2.5-60.9]) and the use of video laryngoscopy (VL) (aOR 5.5 [1.2-24.6]) were associated with the choice to use Roc. CONCLUSIONS: Roc was more frequently chosen for paralysis in the patient cluster with predominantly abnormal peri-intubation vital signs and higher rate of early ED mortality. The use of Roc was associated with hypoxemia prior to RSI and VL.

Waveform capnography: an alternative to physician gestalt in determining optimal intubating conditions after administration of paralytic agents.

PURPOSE: We sought to evaluate the utility of waveform capnography (WC) in detecting paralysis, by using apnoea as a surrogate determinant, as compared with clinical gestalt during rapid sequence intubation. Additionally, we sought to determine if this improves the time to intubation and first pass success rates through more consistent and expedient means of detecting optimal intubating conditions (ie, paralysis). METHODS: A prospective observational cohort study of consecutively enrolled patients was conducted from April to June 2016 at an academic, urban, level 1 trauma centre in New York City. Nasal cannula WC was used to determine the presence of apnoea as a surrogate measure of paralysis versus physician gestalt (ie, blink test, mandible relaxation, and so on). RESULTS: One hundred patients were enrolled (50 in the WC group and 50 in the gestalt group). There were higher proportions of failure to determine optimal intubating conditions (ie, paralysis) in the gestalt group (32%, n=16) versus the WC group (6%, n=3), absolute difference 26, 95% CI 10 to 40. Time to intubation was longer in the gestalt group versus the WC group (136 seconds vs 116 seconds, absolute difference 20 seconds 95% CI 14 to 26). First pass success rates were higher in the WC group verses the gestalt group (92%, 95% CI 85 to 97 vs 88%, 95% CI 88 to 95, absolute difference 4%, 95% CI 1 to 8). CONCLUSION: These preliminary results demonstrate WC may be a useful objective measure to determine the presence of paralysis and optimal in tubating conditions in RSI.

Right-left propensity of cardiogenic cerebral embolism in standard versus bovine aortic arch variant.

Left-hemispheric ischemic strokes are more frequent overall and often have a worse outcome than their right-hemispheric counterparts. We hypothesized that the right-left propensity of CE cerebral infarcts differs between patients with standard and bovine arch variants. We retrospectively identified all patients with acute stroke of the anterior circulation admitted to our primary stroke center between January 2011 and June 2017 who had moderate- to high-risk cardio-embolic sources according to the SSS-TOAST classification. From amongst these patients, only those with available cross-sectional imaging of the aortic arch were included. Lesion side and patterns on diffusion-weighted magnetic resonance imaging were determined blinded to the aortic arch imaging. One hundred and nineteen patients met the TOAST criteria for moderate- or high-risk cardio-embolic source. Of these, 58 (49%) were men and the median age was 71.9 years; 33% of the patients had a bovine arch. The most common etiologies of CE were atrial fibrillation (n = 80 [67%]) and congestive heart failure with ejection fraction <30% (n = 18 [15%]). In patients with bovine arch there was an approximately 50% chance of having a right- or left-sided infarct. Although there was a trend towards right-sided lesions in patients with standard arches, this did not reach statistical significance. No statistically significant difference in embolic stroke laterality was demonstrated in our relatively small sample. Bovine arch could be an independent risk factor for cardio-embolic embolism. Clin. Anat. 31:310-313, 2018. © 2018 Wiley Periodicals, Inc.

The effect of the apneic period on the respiratory physiology of patients undergoing intubation in the ED.

OBJECTIVES: We sought to examine the physiological impact the apneic period has on the respiratory physiology of patients undergoing intubation in the emergency department and whether DAO, the delivery of 15L oxygen by nasal cannula during apnea, can affect the development of respiratory acidosis. METHODS: This was a prospective observational cohort study conducted at an urban academic level 1 trauma center. A convenience sample of 100 patients was taken. Timed data collection forms were completed during the periintubation period. We report the mean ABG and end-tidal CO2 (EtCO2) values between those with normal and prolonged apnea times (>60s) and between those who received DAO and those who did not. RESULTS: 100 patients met our inclusion criteria. There were no significant differences in the pre-RSI ABG values between those who received DAO and those who did not and between those with apnea times less than or >60s. Only in the group of patients with apnea times >60s did significant changes in respiratory physiology occur. DAO did not alter the trend in respiratory acidosis during the periintubation period. EtCO2 increased as apnea times were prolonged, and DAO altered this trend. CONCLUSIONS: Post-RSI EtCO2 increased as apnea times were prolonged. DAO may alter this trend. Statistically significant changes in pH and PaCO2 (mean differences of 0.15 and 12.5, respectively) occurred in the group of patients who had mean apnea times of >60s but not in those with apnea times <60s.

Twenty-four-hour packed red blood cell requirement is the strongest independent prognostic marker of mortality in ED trauma patients.

BACKGROUND: Injury severity score, serum lactate, and shock index help the physician determine the severity of injuries present and have been shown to relate to mortality. We sought to determine if an increasing amount of packed red blood cells (PRBCs) given in the first 24hours of admission is an independent predictor of mortality and how it compares to other validated markers. METHODS: A 6-year retrospective, observational study of adult trauma patients was conducted at a level 1 trauma center. Charts were reviewed for demographic data, amount of PRBC received in the first 24hours, injury severity score, shock index, and lactate levels. Subgroups were used to determine if each variable was an independent predictor of mortality. Correlation coefficients and linear regression were used to determine the strength of correlation between each variable and mortality. RESULTS: One hundred fifty-seven patients met criteria over a 6-year period. The average age was 28years, 93% were male, and 86% had penetrating injuries. The average injury severity score, serum lactate, and shock index were 18, 6.1, and 0.9, respectively. The average amount of blood given was 6.7 U. CONCLUSION: Twenty-four-hour PRBC requirement is both a novel independent predictor of and has the greatest correlation to mortality in adult trauma patients when compared to injury severity score, shock index, and serum lactate.

Comparing biomarkers of traumatic shock: the utility of anion gap, base excess, and serum lactate in the ED.

BACKGROUND: Biomarkers such as serum lactate, anion gap (AG), and base excess (BE) have been shown to be of use in determining shock in patients with seemingly normal vital signs. We seek to determine if these biomarkers can be used interchangeably in patients with trauma in the emergency setting based on their test characteristics and correlation to each other. METHODS: A prospective observational cohort study was undertaken at an urban level 1 trauma center. Baseline vital signs, point-of-care BE, AG, and serum lactate were recorded in all patients who presented for trauma. Correlation was determined by linear regression model. Overall test characteristics and relative risk were calculated. RESULTS: One hundred patients were enrolled. The median age was 30 years (interquartile range, 24-42 years), and 89% were male. Fifty-three percent of injuries were blunt trauma. Pearson correlation of serum lactate to BE was -0.81 (r(2) = 0.66; 95% confidence interval [CI], 0.53-0.75; P < .001), that of BE to AG was -0.71 (r(2) = 0.5; 95% CI, -0.80 to -0.57; P < .01), and that for serum lactate to AG was 0.71 (r(2) = 0.5; 95% CI, 0.57-0.80; P < .01). CONCLUSIONS: This study demonstrates that the biomarkers have similar test characteristics which may make them interchangeable as indicators for the presence of occult shock in patients with trauma. Lactate and BE correlate well with each other; however, AG was not as strongly correlated with either.

Determining the utility of metabolic acidosis for trauma patients in the emergency department.

BACKGROUND: Metabolic acidosis has been proposed as the gold standard to define shock in trauma patients. Other studies determine the presence of shock by use of serum lactate. However, not all medical centers have the ability to utilize point-of-care lactate at bedside. OBJECTIVE: This study seeks to determine the relationship between serum lactate and metabolic acidemia in trauma patients, and if metabolic acidemia can be used to guide therapy. We hypothesized that acidemia would be strongly correlated with lactate levels and would be associated with activation of massive transfusion (MT) in the presence of shock in trauma. METHODS: This was a prospective observational cohort study, level II evidence; this study aids in decision-making. Setting was a Level I academic, urban trauma center. The study took place from July 1, 2012 to March 1, 2013 and included patients who were ≥18 years old and required trauma team activation. Observations included baseline demographics (age, gender, type of injury), vital signs, point-of-care arterial blood gas, lactate, and need for MT. RESULTS: One hundred patients were enrolled over the study period. The average age was 34 years, and 82% were male. Forty patients were acidemic (pH < 7.35), and there was a significant difference in lactate levels between the acidemic and non-acidemic groups (p < 0.002). We found a strong correlation between pH and lactate: rs = -0.38, t = -4.03, p < 0.001. In addition, using a logistic regression, we show that pH was associated with activation of MT (p = 0.002). CONCLUSION: This is a prospective observational cohort study with level II evidence. This study demonstrates that acidemia was strongly correlated to serum lactate, lactate levels were higher in the acidemic group, and metabolic acidemia was associated with the activation of MT for trauma patients at our institution.

A retrospective analysis of the utility of an artificial neural network to predict ED volume.

OBJECTIVE: The objectives of this study are to design an artificial neural network (ANN) and to test it retrospectively to determine if it may be used to predict emergency department (ED) volume. METHODS: We conducted a retrospective review of patient registry data from February 4, 2007, to December 31, 2009, from an inner city, tertiary care hospital. We harvested data regarding weather, days of week, air quality, and special events to train the ANN. The ANN belongs to a class of neural networks called multilayer perceptrons. We designed an ANN composed of 37 input neurons, 22 hidden neurons, and 1 output neuron designed to predict the daily number of ED visits. The training method is a supervised backpropagation algorithm that uses mean squared error to minimize the average squared error between the ANN's output and the number of ED visits over all the example pairs. RESULTS: A linear regression between the predicted and actual ED visits demonstrated an R2 of 0.957 with a slope of 0.997. Ninety-five percent of the time, the ANN was within 20 visits. CONCLUSION: The results of this study show that a properly designed ANN is an effective tool that may be used to predict ED volume. The scatterplot demonstrates that the ANN is least predictive at the extreme ends of the spectrum suggesting that the ANN may be missing important variables. A properly calibrated ANN may have the potential to allow ED administrators to staff their units more appropriately in an effort to reduce patient wait times, decrease ED physician burnout rates, and increase the ability of caregivers to provide quality patient care. A prospective is needed to validate the utility of the ANN.

Placement of a central venous catheter in the antecubital vein using a modified seldinger technique.

PURPOSE: To describe a case of a patient requiring inotropic support without central venous access in which the central venous catheter (CVC) was placed in the antecubital vein using a modified seldinger technique. BACKGROUND: Placement of CVC in the field in retrieval medicine can be time consuming and is not without risk of complication. Minimizing time in the field can lead to better outcomes for patients who are seriously medically ill or traumatically injured. The ED also offers a more controlled environment for the safe and accurate placement of CVCs. However, there are times in the prehospital environment when more secure access than peripheral is needed in order to administer the appropriate treatment. Herein, a modified seldinger technique is described for the peripheral placement of a CVC. CASE REPORT: A 53-year-old man presented to a remote health clinic in the outback of Australia with complaints of weakness, persistent vomiting and chest pain. He subsequently arrested for a brief period (∼3 minutes) from suspected hyperkalemia complicated by MI and upon resuscitation was bradycardic, obtunded and hypotensive. Clinic staff were only able to gain an 18G left antecubital IV. The patient required an adrenaline infusion, IVF and other medications. Using the angiocatherter already in place, a guide wire was placed through and a quadruple lumen CVC was placed without complication allowing for infusion of medications (adrenaline drip, meropenem) and IVF. The catheter was removed after a CVC was placed under US guidance and sterile conditions in the ICU 12 hours later. CONCLUSION: This case represents a dilemma faced in the prehospital environment by retrieval teams and offers a novel technique as a temporizing solution until appropriate CVC access can be gained.

Intraosseous access in trauma by air medical retrieval teams.

Trauma accounts for a significant portion of overall mortality globally. Hemorrhage is the second major cause of mortality in the prehospital environment. Air medical retrieval services throughout the world have been developed to help improve the outcomes of patients suffering from a broad range of medical conditions, including trauma. These services often utilize intraosseous (IO) devices as an alternative means for access of both medically ill and traumatically injured patients in austere environments. However, studies have suggested that IO access cannot reach acceptable rates for massive transfusion. We review the subject to find the answer of whether IO access should be performed by air medical teams in the prehospital setting, or would central venous (CVC) access be more appropriate? We decided to assess the literature for capacity of IO access to meet resuscitation requirements in the prehospital management of trauma. We also decided to compare the insertion and complication characteristics of IO and CVC access.

Re-evaluating the diagnostic accuracy of the tongue blade test: still useful as a screening tool for mandibular fractures?

BACKGROUND: Mandibular fractures are one of the most frequently seen injuries in trauma. In terms of facial trauma, mandible fractures constitute 40%-62% of all facial bone fractures. The tongue blade test (TBT) has been shown to be a sensitive screening tool when compared with plain films. However, recent studies have demonstrated that computed tomography (CT) scan is more sensitive for determining mandible fractures than the traditionally used plain films. OBJECTIVE: The purpose of the study was to determine the sensitivity and specificity of the TBT as compared with the new gold standard of radiologic imaging, CT scan. METHODS: Any patient suffering from facial trauma was prospectively enrolled during the study period (August 1, 2010 to April 11, 2012) at a single urban, academic Emergency Department. A TBT was performed by the resident physician and confirmed by the supervising attending. CT facial bones were then obtained for the ultimate diagnosis. Inter-rater reliability (κ) was calculated, along with sensitivity, specificity, negative predictive value, and likelihood ratio (-) based on a 2 × 2 contingency table generated. RESULTS: During the study period, 190 patients were enrolled. Inter-rater reliability was κ = 0.96 (95% confidence interval [CI] 0.93-0.99). The following parameters were then calculated based on the contingency table: sensitivity 0.95 (95% CI 0.88-0.98), specificity 0.68 (95% CI 0.57-0.77), negative predictive value 0.92 (95% CI 0.82-0.97), and likelihood ratio (-) 0.07 (95% CI 0.03-0.18). CONCLUSIONS: Based on the test characteristics calculated (negative predictive value 0.92, sensitivity 0.95, likelihood ratio -0.07), the TBT is a useful screening tool to determine the need for radiologic imaging.

A sedentary job? Measuring the physical activity of emergency medicine residents.

BACKGROUND: The debate on the quality of health care provided in the United States has continued to be waged as concerns have grown over the years. Stress, sleep deprivation, poor diet, and lack of exercise may lead to inadequate work performance by physicians. OBJECTIVE: This study was undertaken to determine whether Emergency Medicine (EM) residents satisfy daily recommendations for total number of steps taken per day set forth by the Centers for Disease Control and Prevention and Surgeon General in a 12-h shift. METHODS: An observational prospective cohort study was conducted between August 2009 and November 2009 at an urban Level I trauma center with an annual census of over 165,000 Emergency Department (ED) visits per year. The mean number of steps taken by EM residents during 12-h shifts was measured. RESULTS: Mean steps taken during a shift were 7333 (95% confidence interval 6901-7764). Only nine (9.9%) pedometer readings reached the target level of 10,000 (10 K) steps or above. A t-test was used to compare steps with the hypothesized 10 K steps target. Recordings of 10K steps or greater were not correlated with ED sections (p=0.60) shift (medical vs. surgical, p=0.65) or ED census (r(2)<0.0017). CONCLUSION: A majority of residents (90%) did not meet the target number of steps for shifts. More rigorous charting needs, overcrowding, or even spatial limitations may explain this. This warrants further investigation to determine if some daily physical activity regimens may help improve the overall well-being of EM residents.