Society of Critical Care Medicine Guidelines on Recognizing and Responding to Clinical Deterioration Outside the ICU: 2023.

RATIONALE: Clinical deterioration of patients hospitalized outside the ICU is a source of potentially reversible morbidity and mortality. To address this, some acute care hospitals have implemented systems aimed at detecting and responding to such patients. OBJECTIVES: To provide evidence-based recommendations for hospital clinicians and administrators to optimize recognition and response to clinical deterioration in non-ICU patients. PANEL DESIGN: The 25-member panel included representatives from medicine, nursing, respiratory therapy, pharmacy, patient/family partners, and clinician-methodologists with expertise in developing evidence-based Clinical Practice Guidelines. METHODS: We generated actionable questions using the Population, Intervention, Control, and Outcomes (PICO) format and performed a systematic review of the literature to identify and synthesize the best available evidence. We used the Grading of Recommendations Assessment, Development, and Evaluation Approach to determine certainty in the evidence and to formulate recommendations and good practice statements (GPSs). RESULTS: The panel issued 10 statements on recognizing and responding to non-ICU patients with critical illness. Healthcare personnel and institutions should ensure that all vital sign acquisition is timely and accurate (GPS). We make no recommendation on the use of continuous vital sign monitoring among unselected patients. We suggest focused education for bedside clinicians in signs of clinical deterioration, and we also suggest that patient/family/care partners' concerns be included in decisions to obtain additional opinions and help (both conditional recommendations). We recommend hospital-wide deployment of a rapid response team or medical emergency team (RRT/MET) with explicit activation criteria (strong recommendation). We make no recommendation about RRT/MET professional composition or inclusion of palliative care members on the responding team but suggest that the skill set of responders should include eliciting patients' goals of care (conditional recommendation). Finally, quality improvement processes should be part of a rapid response system. CONCLUSIONS: The panel provided guidance to inform clinicians and administrators on effective processes to improve the care of patients at-risk for developing critical illness outside the ICU.

Executive Summary: Society of Critical Care Medicine Guidelines on Recognizing and Responding to Clinical Deterioration Outside the ICU.

RATIONALE: Clinical deterioration of patients hospitalized outside the ICU is a source of potentially reversible morbidity and mortality. To address this, some acute care facilities have implemented systems aimed at detecting and responding to such patients. OBJECTIVES: To provide evidence-based recommendations for hospital clinicians and administrators to optimize recognition and response to clinical deterioration in non-ICU patients. PANEL DESIGN: The 25-member panel included representatives from medicine, nursing, respiratory therapy, pharmacy, patient/family partners, and clinician-methodologists with expertise in developing evidence-based clinical practice guidelines. METHODS: We generated actionable questions using the Population, Intervention, Control, and Outcomes format and performed a systematic review of the literature to identify and synthesize the best available evidence. We used the Grading of Recommendations Assessment, Development, and Evaluation approach to determine certainty in the evidence and to formulate recommendations and good practice statements (GPSs). RESULTS: The panel issued 10 statements on recognizing and responding to non-ICU patients with critical illness. Healthcare personnel and institutions should ensure that all vital sign acquisition is timely and accurate (GPS). We make no recommendation on the use of continuous vital sign monitoring among "unselected" patients due to the absence of data regarding the benefit and the potential harms of false positive alarms, the risk of alarm fatigue, and cost. We suggest focused education for bedside clinicians in signs of clinical deterioration, and we also suggest that patient/family/care partners' concerns be included in decisions to obtain additional opinions and help (both conditional recommendations). We recommend hospital-wide deployment of a rapid response team or medical emergency team (RRT/MET) with explicit activation criteria (strong recommendation). We make no recommendation about RRT/MET professional composition or inclusion of palliative care members on the responding team but suggest that the skill set of responders should include eliciting patients' goals of care (conditional recommendation). Finally, quality improvement processes should be part of a rapid response system (GPS). CONCLUSIONS: The panel provided guidance to inform clinicians and administrators on effective processes to improve the care of patients at-risk for developing critical illness outside the ICU.

Chest Decompressions - The Driver of CPR Efficacy: Exploring the Relationship Between Compression Rate, Depth, Recoil Velocity, and End-Tidal CO2.

OBJECTIVE: Cardiopulmonary arrest survival is dependent on optimization of perfusion via high quality cardiopulmonary resuscitation (CPR), defined by a complex dynamic between rate, depth, and recoil velocity. Here we explore the interaction between these metrics and create a model that explores the impact of these variables on compression efficacy. METHODS: This study was performed in a large urban/suburban fire-based emergency medical services (EMS) system over a nine-month period from 2019 to 2020. Manual chest compression parameters [rate/depth/recoil velocity] from a cohort of out-of-hospital cardiac arrest (OOHCA) victims were abstracted from monitor defibrillators (ZOLL X-series) and end-tidal carbon dioxide (ETCO2) from sensors. The mean values of these parameters were modeled against each other using multiple regression and structural equation modeling with ETCO2 as a dependent variable. RESULTS: Data from a total of 335 patients were analyzed. Strong linear relationships were observed between compression depth/recoil velocity (r = .87, p < .001), ETCO2/depth (r = .23, p < .001) and ETCO2/recoil velocity (r = .61, p < .001). Parabolic relationships were observed between rate/depth (r = .39, p < .001), rate/recoil velocity (r = .26, p < .001), and ETCO2/rate (r = .20, p = .003). Rate, depth, and recoil velocity were modeled as independent variables and ETCO2 as a dependent variable with excellence model performance suggesting the primary driver of stroke volume to be recoil velocity rather than compression depth. CONCLUSIONS: We used manual CPR metrics from out of hospital cardiac arrests to model the relationship between CPR metrics. These results consistently support the importance of chest recoil on CPR hemodynamics, suggesting that guidelines for optimal CPR should emphasize the importance of maximum chest recoil.

A Descriptive Analysis of Air Medical Pediatric Rapid Sequence Intubation: Successes and Opportunities.

OBJECTIVE: Advanced airway management, including the use of rapid sequence intubation (RSI), is fundamental in resuscitation. However, the reported experience with pediatric airway management is limited because of the relatively low number of emergency RSI procedures in children. The aim of this study was to document the experience with pediatric RSI in a large air medical database and explore opportunities for improvement. METHODS: All pediatric patients (age < 18 years) undergoing RSI by air medical crews between 2015 and 2019 were included in this analysis. Subjects were divided a priori into 3 age subgroups (0-2 years, 3-8 years, and 9-17 years). The primary variables of interest included overall intubation success, first-attempt intubation success, and first-attempt intubation success without desaturation. The rates of positive-pressure ventilation (PPV) use for preoxygenation and oxygen desaturation were also explored. RESULTS: A total of 1,091 pediatric RSI patients were included. The overall intubation success rate was 98% (0-2 years = 96%, 3-8 years = 97%, and 9-17 years = 98%), with 91% intubated on the first attempt (0-2 years = 86%, 3-8 years = 90%, and 9-17 years = 92%) and 87% intubated on the first attempt without oxygen desaturation (0-2 years = 80%, 3-8 years = 88%, and 9-17 years = 90%). A sharp decline in intubation success was observed with preoxygenation SpO2 values < 97% across all patients. Younger patients (0-2 years) had lower initial SpO2 values and decreased first-attempt success rates with and without desaturation. These patients were less likely to receive PPV during preoxygenation attempts and had lower use of video laryngoscopy or a bougie on the initial intubation attempt. CONCLUSION: In this study, we documented high success rates for air medical pediatric RSI. Higher target SpO2 values may be justified during preoxygenation. Intubation success, PPV use for preoxygenation, video laryngoscopy, and the use of a bougie were lower for younger patients.

Bolus Vasopressor Use for Air Medical Rapid Sequence Intubation: The Vasopressor Intravenous Push to Enhance Resuscitation Trial.

BACKGROUND: Rapid sequence intubation (RSI) may compromise perfusion because of the use of sympatholytic medications as well as subsequent positive pressure ventilation. The use of bolus vasopressor agents may reverse hypotension and prevent arrest. METHODS: This was a prospective, observational study enrolling air medical patients with critical peri-RSI hypotension (systolic blood pressure [SBP] < 90 mm Hg) to receive either arginine vasopressin (aVP), 2 U intravenously every 5 minutes, for trauma patients or phenylephrine (PE), 200 µg intravenously every 5 minutes, for nontrauma patients. The main outcome measures included an increase in SBP, a reversal of hypotension, and the occurrence of dysrhythmia or hypertension (SBP > 160 mm Hg) within 20 minutes of vasopressor administration. RESULTS: A total of 523 patients (344 aVP and 179 PE) were enrolled over 2 years. An increase in SBP was observed in 326 aVP patients (95%), with reversal of hypotension in 272 patients (79%). An increase in SBP was observed in 171 PE patients (96%), with reversal of hypotension in 148 patients (83%). A low rate of rebound hypertension was observed for both aVP and PE patients. CONCLUSION: Both aVP and PE appear to be safe and effective for treating critical hypotension in the peri-RSI period.

Optimizing Physiology During Prehospital Airway Management: An NAEMSP Position Statement and Resource Document.

Airway management is a critical component of resuscitation but also carries the potential to disrupt perfusion, oxygenation, and ventilation as a consequence of airway insertion efforts, the use of medications, and the conversion to positive-pressure ventilation. NAEMSP recommends:Airway management should be approached as an organized system of care, incorporating principles of teamwork and operational awareness.EMS clinicians should prevent or correct hypoxemia and hypotension prior to advanced airway insertion attempts.Continuous physiological monitoring must be used during airway management to guide the timing of, limit the duration of, and inform decision making during advanced airway insertion attempts.Initial and ongoing confirmation of advanced airway placement must be performed using waveform capnography. Airway devices must be secured using a reliable method.Perfusion, oxygenation, and ventilation should be optimized before, during, and after advanced airway insertion.To mitigate aspiration after advanced airway insertion, EMS clinicians should consider placing a patient in a semi-upright position.When appropriate, patients undergoing advanced airway placement should receive suitable pharmacologic anxiolysis, amnesia, and analgesia. In select cases, the use of neuromuscular blocking agents may be appropriate.

The Use of Ketamine for Air Medical Rapid Sequence Intubation Was Not Associated With a Decrease in Hypotension or Cardiopulmonary Arrest.

OBJECTIVE: Rapid sequence intubation (RSI) is associated with a number of complications that can increase morbidity and mortality. Among RSI agents used to blunt awareness of the procedure and produce amnesia, ketamine is unique in its classification as a dissociative agent rather than a central nervous system depressant. Thus, ketamine should have a lower risk of peri-RSI hypotension because of the minimal sympatholysis compared with other agents. Recent recommendations include the use of ketamine for RSI in hemodynamically unstable patients. The main goal of this analysis was to explore the incidence of hypotension and/or cardiopulmonary arrest in patients receiving ketamine, etomidate, midazolam, and fentanyl during air medical RSI. We hypothesized that ketamine would be associated with a lower risk of hemodynamic complications, particularly after adjusting for covariables reflecting patient acuity. In addition, we anticipated that an increased prevalence of ketamine use would be associated with a decreased incidence of peri-RSI hypotension and/or arrest. METHODS: This was a retrospective, observational study using a large air medical airway database. A waiver of informed consent was granted by our institutional review board. Descriptive statistics were used to present demographic and clinical data. The incidence rates of hypotension and cardiopulmonary arrest were calculated for each sedative/dissociative agent. Multivariable logistic regression was used to calculate the odds ratios of both hypotension and arrest for each of the sedative/dissociative agents. The prevalence of use for each agent and the incidence of hemodynamic complications (hypotension and arrest) were determined over time. RESULTS: A total of 7,466 RSI patients were included in this analysis. The use of ketamine increased over the duration of the study. Ketamine was associated with a higher incidence of both hypotension and arrest compared with other agents, even after adjustment for multiple covariables. The overall incidence of hypotension, desaturation, and cardiopulmonary arrest did not change over the study period. CONCLUSIONS: Although the incidence of hemodynamic complications was higher in patients receiving ketamine, this may reflect a selection bias toward more hemodynamically unstable patients in the ketamine cohort. The incidence of hypotension and arrest did not change over time despite an increase in the prevalence of ketamine use for air medical RSI. These data do not support a safer hemodynamic profile for ketamine.

A Continuous Quality Improvement Airway Program Results in Sustained Increases in Intubation Success.

INTRODUCTION: Airway management is a critical skill for air medical providers, including the use of rapid sequence intubation (RSI) medications. Mediocre success rates and a high incidence of complications has challenged air medical providers to improve training and performance improvement efforts to improve clinical performance. OBJECTIVES: The aim of this research was to describe the experience with a novel, integrated advanced airway management program across a large air medical company and explore the impact of the program on improvement in RSI success. METHODS: The Helicopter Advanced Resuscitation Training (HeART) program was implemented across 160 bases in 2015. The HeART program includes a novel conceptual framework based on thorough understanding of physiology, critical thinking using a novel algorithm, difficult airway predictive tools, training in the optimal use of specific airway techniques and devices, and integrated performance improvement efforts to address opportunities for improvement. The C-MAC video/direct laryngoscope and high-fidelity human patient simulation laboratories were implemented during the study period. Chi-square test for trend was used to evaluate for improvements in airway management and RSI success (overall intubation success, first-attempt success, first-attempt success without desaturation) over the 25-month study period following HeART implementation. RESULTS: A total of 5,132 patients underwent RSI during the study period. Improvements in first-attempt intubation success (85% to 95%, p < 0.01) and first-attempt success without desaturation (84% to 94%, p < 0.01) were observed. Overall intubation success increased from 95% to 99% over the study period, but the trend was not statistically significant (p = 0.311). CONCLUSIONS: An integrated advanced airway management program was successful in improving RSI intubation performance in a large air medical company.

A Conceptual Framework to Reduce Inpatient Preventable Deaths.

BACKGROUND: Efforts to reduce preventable deaths in the in-hospital setting should target both cardiopulmonary arrest (CPA) prevention and optimal resuscitation. This requires consideration of a broad range of clinical issues and processes. A comprehensive, integrated system of care (SOC) that links data collection with a modular education program to reduce preventable deaths has not been defined. METHODS: This study was conducted in two urban university hospitals from 2005 to 2009. The Advanced Resuscitation Training (ART) program was implemented in 2007, incorporating hands-on resuscitative skills and in-hospital-specific training with an institutional resuscitation database. Linkage between the database and training modules occurs via the ART Matrix, which classifies all CPA events into the following etiologies: sepsis, hemorrhage, pulmonary embolus, heart failure, tachyarrhythmias, bradyarrhythmias, acute respiratory distress syndrome, non-intubated pulmonary disease, obstructive apnea, traumatic brain injury, ischemic brain injury, and intracranial mass lesions. This taxonomy was validated using descriptive statistics, before-and-after analysis evaluating CPA incidence, and multivariate logistic regression to predict CPA survival. RESULTS: A total of 336 inpatients suffered a cardiopulmonary arrest during the study period-187 in the pre-ART period and 149 in the post-ART period. The vast majority of CPA events were categorized using the ART Matrix with high inter-observer reliability. As anticipated, changes in CPA incidence and survival were observed for some Matrix categories but not others following ART implementation. In addition, multivariate logistic regression revealed strong independent associations between taxonomy classifications and outcome. CONCLUSION: A novel SOC using a unique taxonomy for arrest classification appears to be effective at reducing inpatient CPA incidence and outcome.

HEAVEN Criteria: Derivation of a New Difficult Airway Prediction Tool.

OBJECTIVE: Airway management is vitally important in the management of critically ill and injured patients. Current tools to predict the difficult airway have limited application in the emergency airway situation. The aim of this study was to derive a novel difficult airway prediction tool for emergency intubation. METHODS: A retrospective descriptive analysis was performed in a population of air medical rapid sequence intubation patients requiring more than 1 attempt. The Delphi technique was used to classify the etiology for airway failure as reported by providers as part of a performance improvement database. Etiologies were organized into 6 categories, and an acronym was derived for ease of recall. RESULTS: A total of 504 patients were screened, with 63 (12%) patients identified in whom the initial intubation attempt was unsuccessful. All 63 patients (100%) were placed into 1 or more categories (HEAVEN criteria = Hypoxemia, Extremes of size, Anatomic challenges, Vomit/blood/fluid, Exsanguination/anemia, and Neck mobility issues). The database was relatively modest in size, and many patients had more than 1 criterion present, limiting our ability to perform prevalence calculations. CONCLUSION: The HEAVEN criteria represent a set of difficult airway predictors that may be applied prospectively by emergency airway personnel, facilitating airway decision making. These criteria should be validated prospectively.

What is the optimal chest compression depth during out-of-hospital cardiac arrest resuscitation of adult patients?

BACKGROUND: The 2010 American Heart Association guidelines suggested an increase in cardiopulmonary resuscitation compression depth with a target >50 mm and no upper limit. This target is based on limited evidence, and we sought to determine the optimal compression depth range. METHODS AND RESULTS: We studied emergency medical services-treated out-of-hospital cardiac arrest patients from the Resuscitation Outcomes Consortium Prehospital Resuscitation Impedance Valve and Early Versus Delayed Analysis clinical trial and the Epistry-Cardiac Arrest database. We calculated adjusted odds ratios for survival to hospital discharge, 1-day survival, and any return of circulation. We included 9136 adult patients from 9 US and Canadian cities with a mean age of 67.5 years, mean compression depth of 41.9 mm, and a return of circulation of 31.3%, 1-day survival of 22.8%, and survival to hospital discharge of 7.3%. For survival to discharge, the adjusted odds ratios were 1.04 (95% CI, 1.00-1.08) for each 5-mm increment in compression depth, 1.45 (95% CI, 1.20-1.76) for cases within 2005 depth range (>38 mm), and 1.05 (95% CI, 1.03-1.08) for percentage of minutes in depth range (10% change). Covariate-adjusted spline curves revealed that the maximum survival is at a depth of 45.6 mm (15-mm interval with highest survival between 40.3 and 55.3 mm) with no differences between men and women. CONCLUSIONS: This large study of out-of-hospital cardiac arrest patients demonstrated that increased cardiopulmonary resuscitation compression depth is strongly associated with better survival. Our adjusted analyses, however, found that maximum survival was in the depth interval of 40.3 to 55.3 mm (peak, 45.6 mm), suggesting that the 2010 American Heart Association cardiopulmonary resuscitation guideline target may be too high. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00394706.

Chest compression rates and survival following out-of-hospital cardiac arrest.

OBJECTIVE: Guidelines for cardiopulmonary resuscitation recommend a chest compression rate of at least 100 compressions/min. A recent clinical study reported optimal return of spontaneous circulation with rates between 100 and 120/min during cardiopulmonary resuscitation for out-of-hospital cardiac arrest. However, the relationship between compression rate and survival is still undetermined. DESIGN: Prospective, observational study. SETTING: Data is from the Resuscitation Outcomes Consortium Prehospital Resuscitation IMpedance threshold device and Early versus Delayed analysis clinical trial. PARTICIPANTS: Adults with out-of-hospital cardiac arrest treated by emergency medical service providers. INTERVENTIONS: None. MEASUREMENTS MAIN RESULTS: Data were abstracted from monitor-defibrillator recordings for the first five minutes of emergency medical service cardiopulmonary resuscitation. Multiple logistic regression assessed odds ratio for survival by compression rate categories (<80, 80-99, 100-119, 120-139, ≥140), both unadjusted and adjusted for sex, age, witnessed status, attempted bystander cardiopulmonary resuscitation, location of arrest, chest compression fraction and depth, first rhythm, and study site. Compression rate data were available for 10,371 patients; 6,399 also had chest compression fraction and depth data. Age (mean±SD) was 67±16 years. Chest compression rate was 111±19 per minute, compression fraction was 0.70±0.17, and compression depth was 42±12 mm. Circulation was restored in 34%; 9% survived to hospital discharge. After adjustment for covariates without chest compression depth and fraction (n=10,371), a global test found no significant relationship between compression rate and survival (p=0.19). However, after adjustment for covariates including chest compression depth and fraction (n=6,399), the global test found a significant relationship between compression rate and survival (p=0.02), with the reference group (100-119 compressions/min) having the greatest likelihood for survival. CONCLUSIONS: After adjustment for chest compression fraction and depth, compression rates between 100 and 120 per minute were associated with greatest survival to hospital discharge.

Preliminary report of a mathematical model of ventilation and intrathoracic pressure applied to prehospital patients with severe traumatic brain injury.

BACKGROUND: Inadvertent hyperventilation is associated with poor outcomes from traumatic brain injury (TBI). Hypocapnic cerebral vasoconstriction is well described and causes an immediate and profound decrease in cerebral perfusion. The hemodynamic effects of positive-pressure ventilation (PPV) remain incompletely understood but may be equally important, particularly in the hypovolemic patient with TBI. OBJECTIVE: Preliminary report on the application of a previously described mathematical model of perfusion and ventilation to prehospital data to predict intrathoracic pressure. METHODS: Ventilation data from 108 TBI patients (76 ground transported, 32 helicopter transported) were used for this analysis. Ventilation rate (VR) and end-tidal carbon dioxide (PetCO2) values were used to estimate tidal volume (VT). The values for VR and estimated VT were then applied to a previously described mathematical model of perfusion and ventilation. This model allows input of various lung parameters to define a pressure-volume relationship, then derives mean intrathoracic pressure (MITP) for various VT and VR values. For this analysis, normal lung parameters were utilized. Separate analyses were performed assuming either fixed or variable PaCO2-PetCO2 differences. Ground and air medical patients were compared with regard to VR, PetCO2, estimated VT, and predicted MITP. RESULTS: A total of 10,647 measurements were included from the 108 TBI patients, representing about 13 minutes of ventilation per patient. Mean VR values were higher for ground patients versus air patients (21.6 vs. 19.7 breaths/min; p < 0.01). Estimated VT values were similar for ground and air patients (399 mL vs. 392 mL; p = NS) in the fixed model but not the variable (636 vs. 688 mL, respectively; p < 0.01). Mean PetCO2 values were lower for ground versus air patients (30.6 vs. 33.8 mmHg; p < 0.01). Predicted MITP values were higher for ground versus air patients, assuming either fixed (9.0 vs. 8.1 mmHg; p < 0.01) or variable (10.9 vs. 9.7 mmHg; p < 0.01) PaCO2-PetCO2 differences. CONCLUSIONS: Predicted MITP values increased with ventilation rates. Future studies to externally validate this model are warranted.

Preoxygenation reduces desaturation events and improves intubation success.

OBJECTIVE: Oxygen desaturation occurs frequently in the course of prehospital rapid sequence intubation (RSI) and is associated with increased morbidity and mortality. Preoxygenation with positive pressure ventilation by bag valve mask may delay the onset of desaturation. The purpose of this study was to evaluate implementation of a targeted preoxygenation protocol including the use of positive pressure ventilation on desaturation events and intubation success during air medical RSI. METHODS: The RSI air medical program airway training model was modified to target an oxygen saturation as measured by pulse oximetry value of ≥ 93% before initial laryngoscopy. A review of oxygen saturation as measured by pulse oximetry tracings was performed for 2 years before and 2 years after implementation of this protocol. The incidence of desaturation events and overall intubation success rates were compared before and after the intervention. RESULTS: One hundred fifty-five RSI procedures were evaluated over the study period. Desaturation events decreased from 58% in the 2 years before algorithm changes to 28% in the first year and 14% in the second year after implementation (P < .01). Intubation success rates increased from 89% to 98% (P < .01). There were no self-reports of aspiration events during the study period. CONCLUSION: A preoxygenation protocol dramatically reduced the incidence of desaturation events and increased intubation success without an increase in the number of reported aspiration events.

A trial of an impedance threshold device in out-of-hospital cardiac arrest.

BACKGROUND: The impedance threshold device (ITD) is designed to enhance venous return and cardiac output during cardiopulmonary resuscitation (CPR) by increasing the degree of negative intrathoracic pressure. Previous studies have suggested that the use of an ITD during CPR may improve survival rates after cardiac arrest. METHODS: We compared the use of an active ITD with that of a sham ITD in patients with out-of-hospital cardiac arrest who underwent standard CPR at 10 sites in the United States and Canada. Patients, investigators, study coordinators, and all care providers were unaware of the treatment assignments. The primary outcome was survival to hospital discharge with satisfactory function (i.e., a score of ≤3 on the modified Rankin scale, which ranges from 0 to 6, with higher scores indicating greater disability). RESULTS: Of 8718 patients included in the analysis, 4345 were randomly assigned to treatment with a sham ITD and 4373 to treatment with an active device. A total of 260 patients (6.0%) in the sham-ITD group and 254 patients (5.8%) in the active-ITD group met the primary outcome (risk difference adjusted for sequential monitoring, -0.1 percentage points; 95% confidence interval, -1.1 to 0.8; P=0.71). There were also no significant differences in the secondary outcomes, including rates of return of spontaneous circulation on arrival at the emergency department, survival to hospital admission, and survival to hospital discharge. CONCLUSIONS: Use of the ITD did not significantly improve survival with satisfactory function among patients with out-of-hospital cardiac arrest receiving standard CPR. (Funded by the National Heart, Lung, and Blood Institute and others; ROC PRIMED ClinicalTrials.gov number, NCT00394706.).

Higher Oxygenation Is Associated with Improved Survival in Severe Traumatic Brain Injury but Not Traumatic Shock.

Pre-hospital resuscitation of critically injured patients traditionally includes supplemental oxygen therapy to address potential hypoxemia. The objective of this study was to explore the association between pre-hospital hypoxemia, hyperoxemia, and mortality in patients with traumatic brain injury (TBI) and traumatic shock. We hypothesized that both hypoxemia and hyperoxemia would be associated with increased mortality. We used the Resuscitation Outcomes Consortium Prospective Observational Prehospital and Hospital Registry for Trauma (ROC PROPHET) database of critically injured patients to identify a severe TBI cohort (pre-hospital Glasgow Coma Scale [GCS] 3-8) and a traumatic shock cohort (systolic blood pressure ≤90 mm Hg and pre-hospital GCS >8). Arterial blood gas (ABG) obtained within 30 min of hospital arrival was required for inclusion. Patients with hypoxemia (PaO2 <80 mm Hg) and hyperoxemia (PaO2 >400 mm Hg) were compared to those with normoxemia (PaO2 80-400 mm Hg) with regard to the primary outcome measure of in-hospital mortality in both the TBI and traumatic shock cohorts. Multiple logistic regression was used to calculate odds ratios (ORs) after adjustment for multiple covariables. In addition, regression spline curves were generated to estimate the risk of death as a continuous function of PaO2 levels. A total of 1248 TBI patients were included, of whom 396 (32%) died before hospital discharge. Associations between hypoxemia and increased mortality (OR, 1.8; 95% confidence interval [CI], 1.2-2.8; p = 0.008) and between hyperoxemia and decreased mortality (OR, 0.6; 95% CI, 0.4-0.9; p = 0.018) were observed. A total of 582 traumatic shock patients were included, of whom 52 (9%) died before hospital discharge. No statistically significant associations were observed between in-hospital mortality and either hypoxemia (OR, 1.0; 95% CI, 0.4-2.4; p = 0.987) or hyperoxemia (OR, 1.9; 95% CI, 0.6-5.7; p = 0.269). Among patients with severe TBI but not traumatic shock, hypoxemia was associated with an increase of in-hospital mortality and hyperoxemia was associated with a decrease of in-hospital mortality.

Expert consensus on difficult airway assessment.

Background: Identifying a potentially difficult airway is crucial both in anaesthesia in the operating room (OR) and non-operation room sites. There are no guidelines or expert consensus focused on the assessment of the difficult airway before, so this expert consensus is developed to provide guidance for airway assessment, making this process more standardized and accurate to reduce airway-related complications and improve safety. Methods: Seven members from the Airway Management Group of the Chinese Society of Anaesthesiology (CSA) met to discuss the first draft and then this was sent to 15 international experts for review, comment, and approval. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) is used to determine the level of evidence and grade the strength of recommendations. The recommendations were revised through a three-round Delphi survey from experts. Results: This expert consensus provides a comprehensive approach to airway assessment based on the medical history, physical examination, comprehensive scores, imaging, and new developments including transnasal endoscopy, virtual laryngoscopy, and 3D printing. In addition, this consensus also reviews some new technologies currently under development such as prediction from facial images and voice information with the aim of proposing new research directions for the assessment of difficult airway. Conclusions: This consensus applies to anesthesiologists, critical care, and emergency physicians refining the preoperative airway assessment and preparing an appropriate intubation strategy for patients with a potentially difficult airway.

What is the role of chest compression depth during out-of-hospital cardiac arrest resuscitation?.

BACKGROUND: The 2010 international guidelines for cardiopulmonary resuscitation recently recommended an increase in the minimum compression depth from 38 to 50 mm, although there are limited human data to support this. We sought to study patterns of cardiopulmonary resuscitation compression depth and their associations with patient outcomes in out-of-hospital cardiac arrest cases treated by the 2005 guideline standards. DESIGN: Prospective cohort. SETTING: Seven U.S. and Canadian urban regions. PATIENTS: We studied emergency medical services treated out-of-hospital cardiac arrest patients from the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest for whom electronic cardiopulmonary resuscitation compression depth data were available, from May 2006 to June 2009. MEASUREMENTS: We calculated anterior chest wall depression in millimeters and the period of active cardiopulmonary resuscitation (chest compression fraction) for each minute of cardiopulmonary resuscitation. We controlled for covariates including compression rate and calculated adjusted odds ratios for any return of spontaneous circulation, 1-day survival, and hospital discharge. MAIN RESULTS: We included 1029 adult patients from seven U.S. and Canadian cities with the following characteristics: Mean age 68 yrs; male 62%; bystander witnessed 40%; bystander cardiopulmonary resuscitation 37%; initial rhythms: Ventricular fibrillation/ventricular tachycardia 24%, pulseless electrical activity 16%, asystole 48%, other nonshockable 12%; outcomes: Return of spontaneous circulation 26%, 1-day survival 18%, discharge 5%. For all patients, median compression rate was 106 per minute, median compression fraction 0.65, and median compression depth 37.3 mm with 52.8% of cases having depth <38 mm and 91.6% having depth <50 mm. We found an inverse association between depth and compression rate ( p < .001). Adjusted odds ratios for all depth measures (mean values, categories, and range) showed strong trends toward better outcomes with increased depth for all three survival measures. CONCLUSIONS: We found suboptimal compression depth in half of patients by 2005 guideline standards and almost all by 2010 standards as well as an inverse association between compression depth and rate. We found a strong association between survival outcomes and increased compression depth but no clear evidence to support or refute the 2010 recommendations of >50 mm. Although compression depth is an important component of cardiopulmonary resuscitation and should be measured routinely, the most effective depth is currently unknown.

Latency of pulse oximetry signal with use of digital probes associated with inappropriate extubation during prehospital rapid sequence intubation in head injury patients: case examples.

BACKGROUND: Endotracheal intubation remains the definitive skill needed for airway management of both medical and surgical patients treated in the prehospital and hospital arenas. Subsequently, rapid sequence intubation (RSI) protocols have been established for various first-line emergency service providers. Because RSI results in the paralysis of skeletal muscles, with a subsequent period of apnea and an increased potential for oxygen desaturation, the accuracy of pulse oximetry (SpO(2)) data is critical in guiding pre-oxygenation efforts and indicating abandonment of intubation attempts to avoid hypoxic injury. Latency of up to 120 s has been demonstrated in conditions producing peripheral vasoconstriction. The influence of peripheral oximetry on the decision-making process during the establishment of a definitive airway has not, to our knowledge, been previously investigated in the prehospital setting. OBJECTIVE: To demonstrate how signal latency may manifest itself as a perceived oxygen desaturation with a subsequent premature abortion of a primary RSI attempt or erroneous extubation. CASE EXAMPLES: We document endotracheal extubation associated with pulse oximetry signal latency during prehospital RSI with the use of digital SpO(2) probes. Two case examples are presented that are taken from a retrospective analysis of pre-hospital RSI data recorded by the City of San Diego Emergency Medical Services. CONCLUSION: To avoid the possibility of mistaking oximetry signal latency for oxygen desaturation during pre-hospital RSI, we propose a conservative approach of aggressive pre-oxygenation to SpO(2) values≥94%, and the use of quantitative continuous capnometry for decision-making regarding whether the endotracheal tube is correctly placed. In cases of hypoxemia despite a properly placed tube, focus should be turned to other causes of post intubation hypoxemia.