Implementation of a Rapid Sequence Intubation Checklist Improves First-Pass Success and Reduces Peri-Intubation Hypoxia in Air Medical Transport.

OBJECTIVE: Rapid sequence intubation (RSI) is a critical skill commonly performed by air medical teams in the United States. To improve safety and reduce potential patient harm, checklists have been implemented by various institutions in intensive care units, emergency departments, and even prehospital air medical programs. However, the literature suggests that checklist use before RSI has not shown improvement in clinically important outcomes in the hospital. It is unclear if RSI checklist use by air medical crews in prehospital environments confers any clinically important benefit. METHODS: This institutional review board-approved project is a before-and-after observational study conducted within a large helicopter ambulance company. The RSI checklist was used by flight crewmembers (flight paramedic/nurse) for over 3 years. Data were evaluated for 8 quarters before and 8 quarters after checklist implementation, spanning December 2014 to March 2019. Data were collected, including the self-reported use of the checklist during intubation attempts, the reason for intubation, and correlation with difficult airway predictors (HEAVEN [Hypoxemia, Extremes of size, Anatomic disruption, Vomit, Exsanguination, Neck mobility/Neurologic injury] criteria), and compared with airway management before the implementation of the checklist. The primary outcome was improved first-pass success (FPS) when compared among those who received RSI before the checklist versus those who received RSI with the checklist. The secondary outcome was a definitive airway sans hypoxia improvement noted on the first pass among adult patients as measured before and after RSI checklist implementation. Post-RSI outcome scenarios were recorded to analyze and validate the effectiveness of the checklist. RESULTS: Ten thousand four hundred five intubations were attempted during the study. FPS was achieved in 90.9% of patients before RSI checklist implementation, and 93.3% achieved FPS postimplementation of the RSI checklist (P ≤ .001). In the preimplementation epoch, 36.2% of patients had no HEAVEN predictors versus 31.5% after RSI checklist implementation. These data showed that before RSI checklist implementation, airways were defined as less difficult than after implementation. CONCLUSION: The implementation of a standardized RSI checklist provided a better identification of deterring factors, affording efficient and accurate actions promoting FPS. Our data suggest that when a difficult airway is identified, using the RSI checklist improves FPS, thereby reducing adverse events.

Motion compensated cone-beam CT reconstruction using ana priorimotion model from CT simulation: a pilot study.

Objective. To combat the motion artifacts present in traditional 4D-CBCT reconstruction, an iterative technique known as the motion-compensated simultaneous algebraic reconstruction technique (MC-SART) was previously developed. MC-SART employs a 4D-CBCT reconstruction to obtain an initial model, which suffers from a lack of sufficient projections in each bin. The purpose of this study is to demonstrate the feasibility of introducing a motion model acquired during CT simulation to MC-SART, coined model-based CBCT (MB-CBCT).Approach. For each of 5 patients, we acquired 5DCTs during simulation and pre-treatment CBCTs with a simultaneous breathing surrogate. We cross-calibrated the 5DCT and CBCT breathing waveforms by matching the diaphragms and employed the 5DCT motion model parameters for MC-SART. We introduced the Amplitude Reassignment Motion Modeling technique, which measures the ability of the model to control diaphragm sharpness by reassigning projection amplitudes with varying resolution. We evaluated the sharpness of tumors and compared them between MB-CBCT and 4D-CBCT. We quantified sharpness by fitting an error function across anatomical boundaries. Furthermore, we compared our MB-CBCT approach to the traditional MC-SART approach. We evaluated MB-CBCT's robustness over time by reconstructing multiple fractions for each patient and measuring consistency in tumor centroid locations between 4D-CBCT and MB-CBCT.Main results. We found that the diaphragm sharpness rose consistently with increasing amplitude resolution for 4/5 patients. We observed consistently high image quality across multiple fractions, and observed stable tumor centroids with an average 0.74 ± 0.31 mm difference between the 4D-CBCT and MB-CBCT. Overall, vast improvements over 3D-CBCT and 4D-CBCT were demonstrated by our MB-CBCT technique in terms of both diaphragm sharpness and overall image quality.Significance. This work is an important extension of the MC-SART technique. We demonstrated the ability ofa priori5DCT models to provide motion compensation for CBCT reconstruction. We showed improvements in image quality over both 4D-CBCT and the traditional MC-SART approach.

Implementing Tourniquet Conversion Guidelines for Civilian EMS and Prehospital Organizations : A Case Report and Review.

Since the first documented use of a tourniquet in 1674, the popularity of tourniquets has waxed and waned. During recent wars and more recently in Emergency Medical Services systems, the tourniquet has been proven to be a valuable tool in the treatment of life-threatening hemorrhage. However, tourniquet use is not without risk, and several studies have demonstrated adverse events and morbidity associated with tourniquet use in the prehospital setting, particularly when left in place for more than 2 h. Consequently, the US military's Committee on Tactical Combat Casualty Care has recommended guidelines for prehospital tourniquet conversion to reduce the risk of adverse events associated with tourniquets once the initial hemorrhage has been controlled. Emergency Medical Services systems that operate in rural, frontier, and austere environments, especially those with transport times to definitive care that routinely exceed 2 h, may consider implementing similar tourniquet conversion guidelines.

Management of Postpartum Hemorrhage in Critical Care Transport.

Postpartum hemorrhage is a relatively common and highly morbid complication of the postpartum period that often requires management by specialized providers at tertiary care facilities. Critical care transport teams may be tasked with transporting postpartum patients who are already experiencing postpartum hemorrhage, but they should also be aware that other peripartum patients may be at risk for developing postpartum hemorrhage while in the process of transport. As such, it is imperative that transport providers understand the signs, symptoms, causes, and complications of postpartum hemorrhage as well as the options for intervention and treatment. This article reviews the current clinical evidence regarding resuscitation and medical management strategies that transport teams should be familiar with as well as more advanced and invasive management techniques they may encounter and be expected to monitor during transport, such as balloon tamponade and aortic balloon occlusion.

Management of Hantavirus Cardiopulmonary Syndrome in Critical Care Transport: A Review.

In 1993, the Southwest found itself staring down a disease then known as "unexplained adult respiratory syndrome." During the outbreak, 12 of 23 known patients died. What we now recognize as hantavirus cardiopulmonary syndrome still remains a rare and deadly disease. Although no cure exists, modern supportive techniques such as extracorporeal membrane oxygenation have increased survival among these patients. Early diagnosis has become the primary factor in patient survival. The initial presentation of hantavirus is similar to acute respiratory distress syndrome, necessitating a high index of suspicion to afford the patient the best chance of survival. Diagnosis is further complicated by prolonged and nonspecific incubation periods making it difficult to pinpoint an exposure. Familiarizing oneself with common clinical presentations, diagnostic strategies, and testing is the best way to increase patient survival. Because hantavirus has a predilection for rural areas, transport to a tertiary facility is paramount to provide the resources necessary to care for these complex patients. Rapid sequence intubation, although common in airway-compromised patients, could prove fatal in the setting of the severe hemodynamic instability found in hantavirus cardiopulmonary syndrome. Anticipation of significant pressor use and fluid administration could likely mean the difference in patient mortality during transport.

An analysis of the regional heterogeneity in tissue elasticity in lung cancer patients with COPD.

Purpose: Recent advancements in obtaining image-based biomarkers from CT images have enabled lung function characterization, which could aid in lung interventional planning. However, the regional heterogeneity in these biomarkers has not been well documented, yet it is critical to several procedures for lung cancer and COPD. The purpose of this paper is to analyze the interlobar and intralobar heterogeneity of tissue elasticity and study their relationship with COPD severity. Methods: We retrospectively analyzed a set of 23 lung cancer patients for this study, 14 of whom had COPD. For each patient, we employed a 5DCT scanning protocol to obtain end-exhalation and end-inhalation images and semi-automatically segmented the lobes. We calculated tissue elasticity using a biomechanical property estimation model. To obtain a measure of lobar elasticity, we calculated the mean of the voxel-wise elasticity values within each lobe. To analyze interlobar heterogeneity, we defined an index that represented the properties of the least elastic lobe as compared to the rest of the lobes, termed the Elasticity Heterogeneity Index (EHI). An index of 0 indicated total homogeneity, and higher indices indicated higher heterogeneity. Additionally, we measured intralobar heterogeneity by calculating the coefficient of variation of elasticity within each lobe. Results: The mean EHI was 0.223 ± 0.183. The mean coefficient of variation of the elasticity distributions was 51.1% ± 16.6%. For mild COPD patients, the interlobar heterogeneity was low compared to the other categories. For moderate-to-severe COPD patients, the interlobar and intralobar heterogeneities were highest, showing significant differences from the other groups. Conclusion: We observed a high level of lung tissue heterogeneity to occur between and within the lobes in all COPD severity cases, especially in moderate-to-severe cases. Heterogeneity results demonstrate the value of a regional, function-guided approach like elasticity for procedures such as surgical decision making and treatment planning.

Takotsubo Cardiomyopathy Syndrome in Critical Care Transport: A Case and Critical Review.

Takotsubo cardiomyopathy syndrome, or simply takotsubo syndrome (TTS), is a form of stress cardiomyopathy thought to be caused by excess catecholamines in association with physical or emotional stress. Providers should maintain a high index of suspicion for TTS in patients with symptoms of acute coronary syndrome, acute decompensated heart failure, substernal chest pain, or dyspnea. However, TTS is a diagnosis of exclusion, and patients should initially be evaluated and treated for other causes, such as acute myocardial infarction. Critical care transport crews may encounter patients with TTS during their primary presentation, before diagnosis, or after the formal diagnosis is made in the catheterization laboratory. Therefore, crews should be familiar with unique aspects of the pathophysiology, diagnosis, and management of TTS. This article presents a case and provides a critical review of TTS for critical care transport clinicians.

Management of Acute Upper Gastrointestinal Bleeding in Critical Care Transport.

Upper gastrointestinal bleeding is a relatively common and life-threatening condition encountered by critical care transport crews. It is of paramount importance that transport crews understand the underlying pathophysiology of variceal and nonvariceal gastrointestinal bleeding as well as the nuanced management of this patient population. This article reviews the current clinical evidence on initial resuscitation, medical management, and advanced invasive therapies (such as balloon tamponade devices) that transport crews should be familiar with to manage these patients. In addition, we present a novel method of continuous balloon pressure monitoring of balloon tamponade devices that is applicable to the transport environment.

Effectiveness of and Adherence to Triage Algorithms During Prehospital Response to Mass Casualty Incidents.

Mass casualty incidents (MCIs) can rapidly exhaust available resources and demand the prioritization of medical response efforts and materials. Principles of triage (i.e., sorting) from the 18th century have evolved into a number of modern-day triage algorithms designed to systematically train responders managing these chaotic events. We reviewed reports and studies of MCIs to determine the use and efficacy of triage algorithms. Despite efforts to standardize MCI responses and improve the triage process, studies and recent experience demonstrate that these methods have limited accuracy and are infrequently used.

Emergency Reflex Action Drills and the Problem with Stress.

Clinicians involved in the care of critically ill patients are often exposed to demanding and stressful situations that require immediate action. Evidence suggests that human performance can be significantly diminished when multiple stressors and stimuli are present. Humans have developed conscious and unconscious methods of dealing with this type of cognitive overload in various high-risk occupations, but these coping methods have not necessarily been structured and adapted to the provision of emergency medical care. Emergency reflex action drills (ERADs) are derived from available evidence in specific domains (e.g., airway management) and develop automaticity of critical skills which engender quick, effective, and reproducible performance with minimal cognitive load. These are pre-planned, practiced responses to specific, high-demand and time-sensitive situations. This article outlines the psychological, cognitive, and behavioral effects of stress that affect performance and necessitate development of ERADs. It also reviews the scientific underpinnings behind how humans have adapted cognitive behavioral techniques to manage under high-stress situations. Finally, this article recommends the adoption of these cognitive tactics via ERADs to enhance clinical practice and provides an example in the context of airway management.

FINGER: A Novel Approach to Teaching Simple Thoracostomy.

For decades, most prehospital clinicians have only been armed with needle thoracostomy to treat a tension pneumothorax, which has a significant failure rate. Following recent changes by the US military, more ground and air transport agencies are adopting simple thoracostomy, also commonly referred to as finger thoracostomy, as a successful alternative. However, surgical procedures performed by prehospital clinicians remain uncommon, intimidating, and challenging. Therefore, it is imperative to adopt a training strategy that is comprehensive, concise, and memorable to best reduce cognitive load on clinicians while in a high-acuity, low-frequency situation. We suggest the following mnemonic to aid in learning and retention of the key procedural steps: FINGER (Find landmarks; Inject lidocaine/pain medicine; No infection allowed; Generous incision; Enter pleural space; Reach in with finger, sweep, reassess). This teaching aid may help develop and maintain competence in the simple thoracostomy procedure, leading to successful treatment of both a tension pneumothorax and hemothorax.

Evaluation of a Disposable Vascular Pressure Device for Pre- and Postmembrane Pressure Monitoring During Venovenous Extracorporeal Membrane Oxygenation.

Membrane pressure monitoring during extracorporeal membrane oxygenation (ECMO) is integral to monitoring circuit health. We compared a disposable vascular pressure device (DVPD) to the transducer pressure bag arterial line (TPBAL) monitoring system to determine whether the DVPD can reliably and accurately monitor membrane pressures during venovenous extracorporeal membrane oxygenation (VV ECMO). We analyzed existing quality assurance data collected at a single center as part of routine circuit performance monitoring and process improvement on a convenience sample of four VV ECMO circuits. We placed and zeroed a DVPD in line with the pre- and postmembrane TPBAL setups in coordination with a standard transducer setup. We recorded DVPD and TPBAL pressure measurements every 4 hours for 2.5 days on the four separate VV ECMO circuits. We compared the standard and DVPD pressures using Bland-Altman plots and methods that accounted for repeated measures in the same subject. We recorded 58 pre/postmembrane pressures. Mean membrane pressure values were similar in the DVPD (pre: 208 mmHg [SD, 50.8]; post: 175 mmHg [46.3]) compared to the standard TPBAL setup (pre: 205 mmHg [52.0]; post: 177 mmHg [46.3]). Using Bland-Altman methods, premembrane pressures were found to be 2.2 mmHg higher (95% confidence interval [CI]: -5.3 to 9.7) in the standard TPBAL setup compared to DVPD and 1.8 mmHg higher (95% CI: -5.3 to 8.9) than the postmembrane pressures. The DVPD provided an accurate measurement of circuit pressure as compared to the TPBAL setup. Across the range of pre- and postmembrane pressures, both methods reliably agreed. Future trials should investigate DVPD accuracy in different environments such as prehospital field cannulation or critical care transport of ECMO patients.

Automated Tumor Segmentation in Radiotherapy.

Autosegmentation of gross tumor volumes holds promise to decrease clinical demand and to provide consistency across clinicians and institutions for radiation treatment planning. Additionally, autosegmentation can enable imaging analyses such as radiomics to construct and deploy large studies with thousands of patients. Here, we review modern results that utilize deep learning approaches to segment tumors in 5 major clinical sites: brain, head and neck, thorax, abdomen, and pelvis. We focus on approaches that inch closer to clinical adoption, highlighting winning entries in international competitions, unique network architectures, and novel ways of overcoming specific challenges. We also broadly discuss the future of gross tumor volumes autosegmentation and the remaining barriers that must be overcome before widespread replacement or augmentation of manual contouring.

A Lost Opportunity: The Use of Unorthodox Training Methods for Prehospital Trauma Care.

Prehospital trauma care guidelines and instruction have advanced significantly over the past 20 years. Although there have been efforts to create a standardized approach to instruction, the use of unorthodox techniques that lack supporting evidence persists. Many instructors use unrealistic scenarios, "no-win" scenarios, and unavoidable failing situations to train students. Doing so, however, creates student confusion and frustration and can result in poor skill acquisition. These training techniques should be reconsidered, with focus placed instead on the development of technical skills and far skill transfer. Knowing when to apply the appropriate type and level of stress within a training scenario can maximize student learning and knowledge retention. Furthermore, modalities such as deliberate practice, cognitive load theory (CLT), and stress exposure training (SET) should be incorporated into training. To improve delivery of prehospital trauma education, instructors should adopt evidence-based educational strategies, grounded in educational and cognitive science, that are targeted at developing long-term information retention as well as consistent, accurate, and timely life-saving interventions.

Impella in Transport: Physiology, Mechanics, Complications, and Transport Considerations.

Cardiogenic shock (CS) represents a spectrum of hemodynamic deficits in which the cardiac output is insufficient to provide adequate tissue perfusion. The Impella (Abiomed Inc, Danvers, MA) device, a contemporary percutaneous ventricular support, is most often indicated for classic, deteriorating, and extremis Society for Coronary Angiography and Intervention stages of CS, which describe CS that is not responsive to optimal medical management and conventional treatment measures. Impella devices are an evolving field of mechanical support that is used with increasing frequency. Critical care transport medicine crews are required to transport patient support by the Impella device with increasing frequency. It is important that critical care transport medicine crews are familiar with the Impella device and are able to troubleshoot complications that may arise in the transport environment. This article reviews many aspects of the Impella device critical to the transport of this complex patient population.

Management of Respiratory Distress and Failure in Morbidly and Super Obese Patients During Critical Care Transport.

Morbidly and super obese patients are a unique patient population that presents critical care transport providers with unique clinical and logistical challenges in the setting of respiratory distress and failure. These patients are more likely to have chronic respiratory issues at baseline, unique anatomic and physiologic abnormalities, and other comorbidities that leave them poorly able to tolerate respiratory illness or injury. This requires specialized understanding of their respiratory mechanics as well as how to tailor standard treatment modalities, such as noninvasive ventilation, to meet their needs. Also, careful and deliberate planning is required to address the specific anatomic and physiologic characteristics of this population if intubation and mechanical ventilation are needed. Finally, their dimensions and weight also have distinct consequences on transport vehicle considerations. This article reviews the pathophysiology, management, and critical care transport considerations for this unique patient population in respiratory distress and failure.

Compliance and Attitudes of Critical Care Transport Providers Regarding a Prehospital Rapid Sequence Intubation Checklist.

Human factors engineering innovations, such as checklists, have been adopted in various acute care settings to improve safety with reasonable compliance and acceptance. In the air medical industry, checklists have been implemented by different teams for critical clinical procedures such as rapid sequence intubation. However, compliance and attitudes toward these human factors engineering innovations in the critical care transport setting are not well described. In this institutional review board-exempt, retrospective review of checklist usage, we assessed rapid sequence intubation checklist compliance and surveyed providers with 5 questions based on Rogers' theory of diffusion of innovation to examine why or why not there was compliance. Our results indicated that compliance with checklist implementation was excellent. The survey questions were consistent with process improvement factors that enhance the spread and acceptance of innovation.

Initiation of Invasive Arterial Pressure Monitoring by Critical Care Transport Crews.

Noninvasive blood pressure monitoring is convenient in the prehospital setting, but its use in the critically ill patient should be carefully considered given documented inaccuracies. Countless therapeutic patient interventions are based on blood pressure parameters, and the prehospital paramedic, nurse, and physician should strongly consider the use of invasive blood pressure monitoring, especially during critical care transport. Radial artery cannulation for arterial blood pressure monitoring is a safe and effective procedure that can reasonably be performed in the prehospital setting by both physicians and nonphysicians. Critical care transport teams should consider clinical guidelines that outline indications and training to safely implement this as a clinical skill.

Automatic triangulated mesh generation of pulmonary airways from segmented lung 3DCTs for computational fluid dynamics.

PURPOSE: Computational fluid dynamics (CFD) of lung airflow during normal and pathophysiological breathing provides insight into regional pulmonary ventilation. By integrating CFD methods with 4D lung imaging workflows, regions of normal pulmonary function can be spared during treatment planning. To facilitate the use of CFD simulations in a clinical setup, a robust, automated, and CFD-compliant airway mesh generation technique is necessary. METHODS: We define a CFD-compliant airway mesh to be devoid of blockages of airflow and leaks in the airway path, both of which are caused by airway meshing errors that occur when using conventional meshing techniques. We present an algorithm to create a CFD-compliant airway mesh in an automated manner. Beginning with a medial skeleton of the airway segmentation, the branches were tracked, and 3D points at which bifurcations occur were identified. Airway branches and bifurcation features were isolated to allow for automated and careful meshing that considered their anatomical nature. RESULTS: We present the meshing results from three state-of-the-art tools and compare them with the meshes generated by our algorithm. The results show that fully CFD-compliant meshes were automatically generated for an ideal geometry and patient-specific CT scans. Using an open-source smoothed-particle hydrodynamics CFD implementation, we compared the airflow using our approach and conventionally generated airway meshes. CONCLUSION: Our meshing algorithm was able to successfully generate a CFD-compliant mesh from pre-segmented lung CT scans, providing an automatic meshing approach that enables interventional CFD simulations to guide lung procedures such as radiotherapy or lung volume reduction surgery.

Ventilation measurements using fast-helical free-breathing computed tomography.

PURPOSE: To examine the use of multiple fast-helical free breathing computed tomography (FHFBCT) scans for ventilation measurement. METHODS: Ten patients were scanned 25 times in alternating directions using a FHFBCT protocol. Simultaneously, an abdominal pneumatic bellows was used as a real-time breathing surrogate. Regions-of-interest (ROIs) were selected from the upper right lungs of each patient for analysis. The ROIs were first registered using a published registration technique (pTV). A subsequent follow-up registration employed an objective function with two terms, a ventilation-adjusted Hounsfield Unit difference and a conservation-of-mass term labeled ΔΓ that denoted the difference between the deformation Jacobian and the tissue density ratio. The ventilations were calculated voxel-by-voxel as the slope of a first-order fit of the Jacobian as a function of the breathing amplitude. RESULTS: The ventilations of the 10 patients showed different patterns and magnitudes. The average ventilation calculated from the deformation vector fields (DVFs) of the pTV and secondary registration was nearly identical, but the standard deviation of the voxel-to-voxel differences was approximately 0.1. The mean of the 90th percentile values of ΔΓ was reduced from 0.153 to 0.079 between the pTV and secondary registration, implying first that the secondary registration improved the conservation-of-mass criterion by almost 50% and that on average the correspondence between the Jacobian and density ratios as demonstrated by ΔΓ was less than 0.1. This improvement occurred in spite of the average of the 90th percentile changes in the DVF magnitudes being only 0.58 mm. CONCLUSIONS: This work introduces the use of multiple free-breathing CT scans for free-breathing ventilation measurements. The approach has some benefits over the traditional use of 4-dimensional CT (4DCT) or breath-hold scans. The benefit over 4DCT is that FHFBCT does not have sorting artifacts. The benefits over breath-hold scans include the relatively small motion induced by quiet respiration versus deep-inspiration breath hold and the potential for characterizing dynamic breathing processes that disappear during breath hold.