Updates on the clinical integration of point-of-care ultrasound in pediatric emergency medicine.

PURPOSE OF REVIEW: There is expanding evidence for point-of-care ultrasound (POCUS) use in pediatric emergency medicine - this review highlights the benefits and challenges in the clinical integration of high-yield POCUS applications. Specifically, it will delve into POCUS applications during resuscitations, controversies of Focused Assessment with Sonography for Trauma (FAST) in pediatric trauma, POCUS-guided procedures, and examples of clinical pathways where POCUS can expedite definitive care. RECENT FINDINGS: POCUS can enhance diagnostic accuracy and aid in management of pediatric patients in shock and help identify reversible causes during cardiac arrest. The use of the FAST in pediatric blunt abdominal trauma remains nuanced - its proper use requires an integration with clinical findings and an appreciation of its limitations. POCUS has been shown to enhance safety and efficacy of procedures such as nerve blocks, incision & drainage, and intravenous access. Integrating POCUS into pathways for conditions such as intussusception and testicular torsion expedites downstream care. SUMMARY: POCUS enhances diagnostic efficiency and management in pediatric patients arriving at the ED with undifferentiated shock, cardiac arrest, or trauma. Additionally, POCUS improves procedural success and safety, and is integral to clinical pathways for expediting definitive care for various pediatric emergencies. Future research should continue to focus on the impact of POCUS on patient outcomes, ensuring user competency, and the expansion of POCUS into diverse settings.

Myocardial Infarction and Cardiac Arrest During Acquisition of 18 F-FDG PET/CT.

ABSTRACT: An 83-year-old man with multiple myeloma and history of coronary artery disease and ischemic cardiomyopathy experienced cardiac arrest during the 18 F-FDG PET/CT examination. The patient had not yet been treated for multiple myeloma. The PET/CT demonstrated focal FDG uptake about the left anterior descending coronary artery. Diffuse intense FDG uptake in the liver and less than normal uptake in other organs of usual FDG distribution were also present, likely due to altered hemodynamics and heart failure in the setting of an acute coronary syndrome.

Feasibility of Magnetic Resonance-Based Conductivity Imaging as a Tool to Estimate the Severity of Hypoxic-Ischemic Brain Injury in the First Hours After Cardiac Arrest.

BACKGROUND: Early identification of the severity of hypoxic-ischemic brain injury (HIBI) after cardiac arrest can be used to help plan appropriate subsequent therapy. We evaluated whether conductivity of cerebral tissue measured using magnetic resonance-based conductivity imaging (MRCI), which provides contrast derived from the concentration and mobility of ions within the imaged tissue, can reflect the severity of HIBI in the early hours after cardiac arrest. METHODS: Fourteen minipigs were resuscitated after 5 min or 12 min of untreated cardiac arrest. MRCI was performed at baseline and at 1 h and 3.5 h after return of spontaneous circulation (ROSC). RESULTS: In both groups, the conductivity of cerebral tissue significantly increased at 1 h after ROSC compared with that at baseline (P = 0.031 and 0.016 in the 5-min and 12-min groups, respectively). The increase was greater in the 12-min group, resulting in significantly higher conductivity values in the 12-min group (P = 0.030). At 3.5 h after ROSC, the conductivity of cerebral tissue in the 12-min group remained increased (P = 0.022), whereas that in the 5-min group returned to its baseline level. CONCLUSIONS: The conductivity of cerebral tissue was increased in the first hours after ROSC, and the increase was more prominent and lasted longer in the 12-min group than in the 5-min group. Our findings suggest the promising potential of MRCI as a tool to estimate the severity of HIBI in the early hours after cardiac arrest.

Increased task-relevant fMRI responsiveness in comatose cardiac arrest patients is associated with improved neurologic outcomes.

Early prediction of the recovery of consciousness in comatose cardiac arrest patients remains challenging. We prospectively studied task-relevant fMRI responses in 19 comatose cardiac arrest patients and five healthy controls to assess the fMRI's utility for neuroprognostication. Tasks involved instrumental music listening, forward and backward language listening, and motor imagery. Task-specific reference images were created from group-level fMRI responses from the healthy controls. Dice scores measured the overlap of individual subject-level fMRI responses with the reference images. Task-relevant responsiveness index (Rindex) was calculated as the maximum Dice score across the four tasks. Correlation analyses showed that increased Dice scores were significantly associated with arousal recovery (P < 0.05) and emergence from the minimally conscious state (EMCS) by one year (P < 0.001) for all tasks except motor imagery. Greater Rindex was significantly correlated with improved arousal recovery (P = 0.002) and consciousness (P = 0.001). For patients who survived to discharge (n = 6), the Rindex's sensitivity was 75% for predicting EMCS (n = 4). Task-based fMRI holds promise for detecting covert consciousness in comatose cardiac arrest patients, but further studies are needed to confirm these findings. Caution is necessary when interpreting the absence of task-relevant fMRI responses as a surrogate for inevitable poor neurological prognosis.

Unveiling pseudo-pulseless electrical activity (pseudo-PEA) in ultrasound-integrated infant resuscitation.

Point-of-care ultrasound (POCUS) holds immense potential to manage critically deteriorating infants within the neonatal intensive care unit (NICU) and is increasingly used in neonatal clinical practice worldwide. Recent ultrasound-based protocols such as the Sonographic Assessment of liFe-threatening Emergencies-Revised (SAFE-R) and Crashing Neonate Protocol (CNP) offer step-by-step guidance for diagnosing and addressing reversible causes of cardiorespiratory collapse. Traditionally, pulseless electrical activity (PEA) has been diagnosed solely based on absent pulses on clinical examination, disregarding myocardial activity. However, integrating POCUS into resuscitation unveils the concept of pseudo-PEA, where cardiac motion activity is observed visually on the ultrasound but fails to generate a detectable pulse due to inadequate cardiac output. Paradoxically, existing neonatal resuscitation protocols lack directives for identifying and effectively leveraging pseudo-PEA insights in infants, limiting their potential to enhance outcomes. Pseudo-PEA is extensively described in adult literature owing to routine POCUS use in resuscitation. This review article comprehensively evaluates the adult pseudo-PEA literature to glean insights adaptable to neonatal care. Additionally, we propose a simple strategy to integrate POCUS during neonatal resuscitation, especially in infants who do not respond to routine measures. CONCLUSION: Pseudo-PDA is a newly recognized diagnosis in infants with the use of POCUS during resuscitation. This article highlights the importance of cross-disciplinary learning in tackling emerging challenges within neonatal medicine. WHAT IS KNOWN: • Point-of-Care ultrasound (POCUS) benefits adult cardiac arrest management, particularly in distinguishing true Pulseless Electrical Activity (PEA) from pseudo-PEA. • Pseudo-PEA is when myocardial motion can be seen on ultrasound but fails to generate palpable pulses or sustain circulation despite evident cardiac electrical activity. WHAT IS NEW: • Discuss recognition and management of pseudo-PEA in infants. • A proposed algorithm to integrate POCUS into active neonatal cardiopulmonary resuscitation (CPR) procedures.

Death and Ultrasound Evidence of the Akinetic Heart in Pediatric Cardiac Arrest.

Point-of-care ultrasound (POCUS) is an expanding noninvasive diagnostic modality used for the management of patients in multiple intensive care and pediatric specialties. POCUS is used to assess cardiac activity and pathology, pulmonary disease, intravascular volume status, intra-abdominal processes, procedural guidance including vascular access, lumbar puncture, thoracentesis, paracentesis, and pericardiocentesis. POCUS has also been used to determine anterograde flow following circulatory arrest when organ donation after circulatory death is being considered. Published guidelines exist from multiple medical societies including the recent guidelines for the use of POCUS in neonatology for diagnostic and procedural purposes.

Focused Ultrasonography in Cardiac Arrest.

Rapid diagnostic tools available to the emergency physician caring for cardiac arrest patients are limited. Focused ultrasound (US), and in particular, focused echocardiography, is a useful tool in the evaluation of patients in cardiac arrest. It can help identify possible causes of cardiac arrest like tamponade and pulmonary embolism, which can guide therapy. US can also yield prognostic information, with lack of cardiac activity being highly specific for failure to achieve return of spontaneous circulation. US may also be used to aid in procedural guidance. Recently, focused transesophageal echocardiography has been used in the emergency department setting.

Resuscitative transesophageal echocardiography in the emergency department: a single-centre case series.

BACKGROUND: Transesophageal echocardiography (TEE) is an emerging tool that can aid emergency physicians in treating patients in cardiac arrest and undifferentiated shock. TEE can aid in diagnosis, resuscitation, identify cardiac rhythms, guide chest compression vectors, and shorten sonographic pulse checks. This study evaluated the proportion of patients who underwent a change in their resuscitation management as a result of emergency department resuscitative TEE. METHODS: This was a single-centre case series of 25 patients who underwent ED resuscitative TEE from 2015 to 2019. The objective of this study is to evaluate the feasibility and clinical impact of resuscitative TEE in critically ill patients in the emergency department. Data including changes in working diagnosis, complications, patient disposition, and survival to hospital discharge were also collected. RESULTS: 25 patients (median age 71, 40% female) underwent ED resuscitative TEE. All patients were intubated prior to probe insertion and adequate TEE views were obtained for every patient. The most common indications for resuscitative TEE were cardiac arrest (64%) and undifferentiated shock (28%). Resuscitation management changed in 76% (N = 19) and working diagnosis changed in 76% (N = 19) of patients. Ten patients died in the ED, 15 were admitted to hospital, and eight survived to hospital discharge. There were no immediate complications (0/15) and two delayed complications (2/15), both of which were minor gastrointestinal bleeding. CONCLUSIONS: The use of ED resuscitative TEE is a practical modality that provides useful diagnostic and therapeutic information for critically ill patients in the emergency department, with an excellent rate of adequate cardiac visualization, and a low complication rate.

Explainable artificial intelligence-based prediction of poor neurological outcome from head computed tomography in the immediate post-resuscitation phase.

Predicting poor neurological outcomes after resuscitation is important for planning treatment strategies. We constructed an explainable artificial intelligence-based prognostic model using head computed tomography (CT) scans taken immediately within 3 h of resuscitation from cardiac arrest and compared its predictive accuracy with that of previous methods using gray-to-white matter ratio (GWR). We included 321 consecutive patients admitted to our institution after resuscitation for out-of-hospital cardiopulmonary arrest with circulation resumption over 6 years. A machine learning model using head CT images with transfer learning was used to predict the neurological outcomes at 1 month. These predictions were compared with the predictions of GWR for multiple regions of interest in head CT using receiver operating characteristic (ROC)-area under curve (AUC) and precision recall (PR)-AUC. The regions of focus were visualized using a heatmap. Both methods had similar ROC-AUCs, but the machine learning model had a higher PR-AUC (0.73 vs. 0.58). The machine learning-focused area of interest for classification was the boundary between gray and white matter, which overlapped with the area of focus when diagnosing hypoxic- ischemic brain injury. The machine learning model for predicting poor outcomes had superior accuracy to conventional methods and could help optimize treatment.

Brain imaging after cardiac arrest.

PURPOSE OF REVIEW: Many patients who survive a cardiac arrest have a disorder of consciousness in the period after resuscitation, and prediction of long-term neurologic outcome requires multimodal assessments. Brain imaging with computed tomography (CT) and MRI is a key component. We aim to provide an overview of the types of neuroimaging available and their uses and limitations. RECENT FINDINGS: Recent studies have evaluated qualitative and quantitative techniques to analyze and interpret CT and MRI to predict both good and poor outcomes. Qualitative interpretation of CT and MRI is widely available but is limited by low inter-rater reliability and lack of specificity around which findings have the highest correlation with outcome. Quantitative analysis of CT (gray-white ratio) and MRI (amount of brain tissue with an apparent diffusion coefficient below certain thresholds) hold promise, though additional research is needed to standardize the approach. SUMMARY: Brain imaging is important for evaluating the extent of neurologic injury after cardiac arrest. Future work should focus on addressing previous methodological limitations and standardizing approaches to qualitative and quantitative imaging analysis. Novel imaging techniques are being developed and new analytical methods are being applied to advance the field.

Neurovascular Hypoxia Trajectories Assessed by Photoacoustic Imaging in a Murine Model of Cardiac Arrest and Resuscitation.

Cardiac arrest is a common cause of death annually mainly due to postcardiac arrest syndrome that leads to multiple organ global hypoxia and dysfunction after resuscitation. The ability to quantify vasculature changes and tissue oxygenation is crucial to adapt patient treatment in order to minimize major outcomes after resuscitation. For the first time, we applied high-resolution ultrasound associated with photoacoustic imaging (PAI) to track neurovascular oxygenation and cardiac function trajectories in a murine model of cardiac arrest and resuscitation. We report the preservation of brain oxygenation is greater compared to that in peripheral tissues during the arrest. Furthermore, distinct patterns of cerebral oxygen decay may relate to the support of vital brain functions. In addition, we followed trajectories of cerebral perfusion and cardiac function longitudinally after induced cardiac arrest and resuscitation. Volumetric cerebral oxygen saturation (sO2) decreased 24 h postarrest, but these levels rebounded at one week. However, systolic and diastolic cardiac dysfunction persisted throughout and correlated with cerebral hypoxia. Pathophysiologic biomarker trends, identified via cerebral PAI in preclinical models, could provide new insights into understanding the pathophysiology of cardiac arrest and resuscitation.

Perioperative Point of Care Ultrasound for Hemodynamic Assessment: A Narrative Review.

While transesophageal echocardiography (TEE) has traditionally been used in perioperative care, there is growing evidence supporting point of care ultrasound (POCUS) for the anesthesiologist in guiding patient care. It is a quick way to non-invasively evaluate hemodynamically unstable patients and ascertain their state of shock, determine volume status, and guide resuscitation in cardiac arrest. In addition, through use of POCUS, the anesthesiologist is able to identify signs of chronic heart disease to provide a more tailored and safer approach to perioperative care.

Parieto-Occipital Injury on Diffusion MRI Correlates with Poor Neurologic Outcome following Cardiac Arrest.

BACKGROUND AND PURPOSE: MR imaging of the brain provides unbiased neuroanatomic evaluation of brain injury and is useful for neurologic prognostication following cardiac arrest. Regional analysis of diffusion imaging may provide additional prognostic value and help reveal the neuroanatomic underpinnings of coma recovery. The purpose of this study was to evaluate global, regional, and voxelwise differences in diffusion-weighted MR imaging signal in patients in a coma after cardiac arrest. MATERIALS AND METHODS: We retrospectively analyzed diffusion MR imaging data from 81 subjects who were comatose for >48 hours following cardiac arrest. Poor outcome was defined as the inability to follow simple commands at any point during hospitalization. ADC differences between groups were evaluated across the whole brain, locally by using voxelwise analysis and regionally by using ROI-based principal component analysis. RESULTS: Subjects with poor outcome had more severe brain injury as measured by lower average whole-brain ADC (740 [SD, 102] × 10-6 mm2/s versus 833 [SD, 23] × 10-6 mm2/s, P < .001) and larger average volumes of tissue with ADC below 650 × 10-6 mms/s (464 [SD, 469] mL versus 62 [SD, 51] mL, P < .001). Voxelwise analysis showed lower ADC in the bilateral parieto-occipital areas and perirolandic cortices for the poor outcome group. ROI-based principal component analysis showed an association between lower ADC in parieto-occipital regions and poor outcome. CONCLUSIONS: Brain injury affecting the parieto-occipital region measured with quantitative ADC analysis was associated with poor outcomes after cardiac arrest. These results suggest that injury to specific brain regions may influence coma recovery.

Femoral Arterial Doppler Use During Active Cardiopulmonary Resuscitation.

STUDY OBJECTIVE: This study explored femoral arterial Doppler during active cardiopulmonary resuscitation (CPR) to identify and characterize the resumptions of cardiac activity without stopping CPR. METHODS: This was a proof-of-concept study exploring arterial Doppler during cardiac arrest. Patients in cardiac arrest undergoing active CPR were prospectively enrolled. Arterial Doppler of the common femoral artery was recorded during CPR and during pauses in CPR. CPR-induced arterial tracings and native cardiac-induced tracings were analyzed for rate and peak systolic velocity. Cardiac activity on echocardiogram during pause in CPR was classified as "absent," "disorganized," or "organized." Descriptive data and survival are presented as mean and 95% confidence intervals (CI), as well as sensitivity and specificity of Doppler during active CPR in detecting native cardiac pulsations. RESULTS: Sixteen patients with 48 paired Doppler recordings during active CPR, pause in CPR, and associated echocardiogram were enrolled. Native cardiac-induced tracings were visible during 39.6% of pauses in CPR (19 of 48) and during 18.8% of the periods of active CPR (9 of 48). Arterial pulsations were more frequently visualized with organized contractions by echocardiogram (10 of 14, 71%) than disorganized contractions (9 of 22, 41%). Arterial Doppler was 100% specific and 50% sensitive in detecting organized cardiac activity during active CPR. Patients with visible native cardiac pulsations during active CPR demonstrated 0% mortality compared with 67% mortality without visible arterial pulsations. CONCLUSION: Arterial Doppler tracings may identify the resumption of native cardiac activity during active CPR; however, more research is needed.