Profound Hypoxemia Research Articles

Systemically injected oxygen within rapidly dissolving microbubbles improves the outcomes of severe hypoxaemia in swine

Acute respiratory failure can cause profound hypoxaemia that leads to organ injury or death within minutes. When conventional interventions are ineffective, the intravenous administration of oxygen can rescue patients from severe hypoxaemia, but at the risk of microvascular obstruction and of toxicity of the carrier material. Here we describe polymeric microbubbles as carriers of high volumes of oxygen (350–500 ml of oxygen per litre of foam) that are stable in storage yet quickly dissolve following intravenous injection, reverting to their soluble and excretable molecular constituents. In swine with profound hypoxaemia owing to acute and temporary (12 min) upper-airway obstruction, the microbubble-mediated delivery of oxygen led to: the maintenance of critical oxygenation, lowered burdens of cardiac arrest, improved survival, and substantially improved neurologic and kidney function in surviving animals. Our findings underscore the importance of maintaining a critical threshold of oxygenation and the promise of injectable oxygen as a viable therapy in acute and temporary hypoxaemic crises.

Prenatal Detection of D-TGA and Novel Interventional Program Decrease Time to Balloon Septostomy.

Infants with dextro-transposition of the great arteries (d-TGA) are at high risk for hemodynamic compromise in the immediate postnatal period due to dependence on intracardiac mixing for oxygen delivery. This period of profound hypoxemia may have long-term implications, as previous studies demonstrated patients with d-TGA are at increased risk for neurocognitive delays despite effective surgical correction in the neonatal period. Balloon atrial septostomy (BAS) is an established intervention that improves intracardiac mixing and perioperative hemodynamics. This retrospective study aimed to quantify the time from birth to BAS and compare short-term outcomes for patients with prenatal and postnatal diagnoses of d-TGA. We identified 68 newborns born with d-TGA who were admitted to our facility between 2013 and 2022 and required BAS within 48h after birth. Halfway through this study, our cardiac interventional team began traveling to a nearby delivery center where a bedside BAS could be performed prior to transferring the patient. We divided the patients into 3 groups-postnatal diagnosis (n = 27), prenatal diagnosis with rapid transport (n = 24), and prenatal diagnosis with interventional team performing a BAS at the delivery hospital (n = 17). The time from birth to BAS was significantly shorter for patients in the interventional program group (1.1h) compared to the rapid transport (4.5h) and postnatal diagnosis groups (9.3h, p value < 0.01). The interventional program group also had lower lactate levels and less acidotic pH compared to the other groups. There was no significant difference in lowest oxygen saturation level, pre-surgical neurologic complication rate, time to surgery, or hospital length of stay. The interventional program proved to be a safe and effective model, as there were no procedural complications and the time to BAS decreased. Long-term follow-up is needed to determine if abating this initial period of hemodynamic instability will lead to improved neurodevelopmental outcomes.

Contribution of intrapulmonary shunt to the pathogenesis of profound hypoxaemia in viral infection: a mechanistic discussion with an illustrative case.

The formation of anastomoses between the pulmonary arteries and pulmonary veins, or the pulmonary and the bronchial circulation, is part of normal foetal lung development. They persist in approximately 30% of adults at rest, and open in almost all adults during exertion. Blood flowing through these anastomoses bypasses the alveolar surface and increases in such shunting can thus cause hypoxaemia. This is now known to contribute to the pathogenesis of hypoxaemia in COVID-19 disease. We here provide evidence to support a similar role in influenza A infection. We describe a case of influenza A infection associated with severe hypoxaemia, poorly responsive to supplemental oxygen and which worsened following the application of continuous positive airway pressure (CPAP), despite the presence of a normal physical examination, chest radiograph and echocardiogram. This combination suggests a significant intrapulmonary (extra-alveolar) shunt as a cause of the severe hypoxaemia. The shunt fraction was estimated to be approximately 57%. Intrapulmonary vascular shunts can contribute substantially to hypoxaemia in viral infection. Seeking to understand the pathogenesis of observed hypoxaemia can help guide respiratory therapy. Mechanistic research may suggest novel therapeutic targets which could assist in avoiding intubation and mechanical ventilatory support.

The use of veno-veno-arterial ECMO as a successful strategy in acute mitral regurgitation secondary to papillary muscle rupture causing cardiogenic shock and profound hypoxemia: a case report

Abstract Acute mitral regurgitation (MR) secondary to papillary muscle rupture is a rare mechanical complication of acute myocardial infarction occurring in 0.05–0.26% of all cases of myocardial infarction. The only treatment is emergency mitral valve surgery with high operative mortality reaching up to 39%. The use of extracorporeal membrane oxygenator (ECMO) as a stabilization strategy and a bridge to recovery may potentially improve the outcome of such cases. Here, we report a case of acute MR presenting with cardiogenic shock and severe hypoxia that required insertion of veno-veno-arterial ECMO initially and followed by emergency mitral valve replacement. This strategy proved useful with full recovery of the patient.

Profound hypoxemia and hypotension during posterior spinal fusion in a spinal muscular atrophy child with severe scoliosis: a case report

BackgroundAnesthesia for spinal muscular atrophy (SMA) patients undergoing spinal deformity surgery is challenging. We report an unusual case of an SMA girl who developed severe intraoperative hypoxemia and hypotension during posterior spinal fusion related with surgical positioning.Case presentationA 13-yr-old girl diagnosed with SMA type 2, severe kyphoscoliosis and thoracic deformity was scheduled for elective posterior spinal fusion. She developed severe hypoxemia and profound hypotension intraoperatively in the prone position with surgical table tilted 45° to the right. Though transesophageal echocardiography (TEE) could not be performed due to limited mouth opening, her preoperative computed tomography revealed a severely distorted thoracic cavity with much reduced volume of the right side. A reasonable explanation was when the surgeons performed surgical procedure with the tilted surgical table, the pressure was directly put on the shortest diameter of the significantly deformed thoracic cavity, causing severe compression of the pulmonary artery, resulting in both hypoxemia and hypotension. The patient stabilized when the surgical table was tilted back and successfully went through the surgery in the leveled prone position.ConclusionsSpinal fusion surgery is beneficial for SMA patients in preventing scoliosis progression and improving ventilation. However, severe scoliosis and thoracic deformities put them at risk of both hemodynamic and respiratory instability during surgical positioning. When advanced monitoring like TEE is not practical intraoperatively, preoperative imaging may help with differential diagnosis, and guide the surgical positioning to minimize mechanical compression of the thoracic cavity, thereby helping the patient complete the surgery safely.

Ventilatory Management of Patients with Acute Respiratory Distress Syndrome Due to SARS-CoV-2.

The emergence of the new SARS-CoV-2 in December 2019 caused a worldwide pandemic of the resultant disease, COVID-19. There was a massive surge in admissions to intensive care units (ICU), notably of patients with hypoxaemic acute respiratory failure. In these patients, optimal oxygen therapy was crucial. In this article, we discuss tracheal intubation to provide mechanical ventilation in patients with hypoxaemic acute respiratory failure due to SARS-CoV-2. We first describe the pathophysiology of respiratory anomalies leading to acute respiratory distress syndrome (ARDS) due to infection with SARS-CoV-2, and then briefly review management, focusing particularly on the ventilation strategy. Overall, the ventilatory management of ARDS due to SARS-CoV-2 infection is largely the same as that applied in ARDS from other causes, and lung-protective ventilation is recommended. The difference lies in the initial clinical presentation, with profound hypoxaemia often observed concomitantly with near-normal pulmonary compliance.

DELAYED HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS (HLH) DIAGNOSIS IN A PATIENT WITH PULMONARY SARCOIDOSIS AND NEWLY DIAGNOSED T-CELL LYMPHOMA: A CASE REPORT

DELAYED HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS (HLH) DIAGNOSIS IN A PATIENT WITH PULMONARY SARCOIDOSIS AND NEWLY DIAGNOSED T-CELL LYMPHOMA: A CASE REPORT

Implementation of a Revised Montpellier Bundle on the Outcome of Intubation in Critically Ill Patients: A Quality Improvement Project.

The feasibility of implementing a revised Montpellier intubation bundle incorporating recent evidences was tested in a quality-improvement project. It was hypothesized that this "Care Bundle" implementation would reduce intubation-related complications. The project was conducted in an 18-bedded multidisciplinary intensive care unit (ICU). Baseline data for intubations were collected over 3-month "Control Period". During the 2-month "Interphase", a revised intubation bundle was developed, and staff members involved in the intubation process were extensively trained on different aspects of intubation with emphasis on bundle components. Various components of the bundle were pre-intubation fluid loading, pre-oxygenation with NIV plus PS, positive-pressure ventilation post-induction, succinylcholine as a first-line induction agent, routine use of stylet, and lung recruitment within 2 minutes of intubation. Intubation data were collected again in the 3-month "Intervention Period". Data were collected for 61 and 64 intubations, respectively, during control and intervention periods. There was significant improvement in compliance to five of six-bundle components; improvement in pre-intubation fluid loading during the intervention period did not reach statistical significance. Overall, at least 3 components of the bundle were complied within over 92% of intubations in the intervention period. However, whole-bundle compliance was limited to 14.3%. Incidences of major complications were reduced significantly in the intervention period (23.8% vs 45.9%, p = 0.01). There was significant reduction in profound hypotension (21.77% vs 29.51%, p = 0.04) and a nonsignificant 11.89% reduction in profound hypoxemia. There were no differences in minor complications. Implementation of an evidence-based revised Montpellier intubation bundle is feasible and it reduces major complications related to endotracheal intubation. Ghosh S, Salhotra R, Arora G, Lyall A, Singh A, Kumar N, et al. Implementation of a Revised Montpellier Bundle on the Outcome of Intubation in Critically Ill Patients: A Quality Improvement Project. Indian J Crit Care Med 2022;26(10):1106-1114.

Preventing unrecognised oesophageal intubation: a consensus guideline from the Project for Universal Management of Airways and international airway societies.

Across multiple disciplines undertaking airway management globally, preventable episodes of unrecognised oesophageal intubation result in profound hypoxaemia, brain injury and death. These events occur in the hands of both inexperienced and experienced practitioners. Current evidence shows that unrecognised oesophageal intubation occurs sufficiently frequently to be a major concern and to merit a co-ordinated approach to address it. Harm from unrecognised oesophageal intubation is avoidable through reducing the rate of oesophageal intubation, combined with prompt detection and immediate action when it occurs. The detection of 'sustained exhaled carbon dioxide' using waveform capnography is the mainstay for excluding oesophageal placement of an intended tracheal tube. Tube removal should be the default response when sustained exhaled carbon dioxide cannot be detected. If default tube removal is considered dangerous, urgent exclusion of oesophageal intubation using valid alternative techniques is indicated, in parallel with evaluation of other causes of inability to detect carbon dioxide. The tube should be removed if timely restoration of sustained exhaled carbon dioxide cannot be achieved. In addition to technical interventions, strategies are required to address cognitive biases and the deterioration of individual and team performance in stressful situations, to which all practitioners are vulnerable. These guidelines provide recommendations for preventing unrecognised oesophageal intubation that are relevant to all airway practitioners independent of geography, clinical location, discipline or patient type.

ICU strain and outcome in COVID-19 patients-A multicenter retrospective observational study.

PurposeTo compare the characteristics, management, and prognosis of patients admitted to intensive care units (ICU) for coronavirus disease (COVID)-19 during the first two waves of the outbreak and to evaluate the relationship between ICU strain (ICU demand due to COVID-19 admissions) and mortality.MethodsIn a multicentre retrospective study, 1166 COVID-19 patients admitted to five ICUs in France between 20 February and 31 December 2020 were included. Data were collected at each ICU from medical records. A Cox proportional-hazards model identified factors associated with 28-day mortality.Results640 patients (55%) were admitted during the first wave (February to June 2020) and 526 (45%) during the second wave (July to December 2020). ICU strain was lower during the second wave (-0.81 [-1.04 –-0.31] vs. 1.18 [-0.34–1.29] SD when compared to mean COVID-19 admission in each center during study period, P<0.001). Patients admitted during the second wave were older, had more profound hypoxemia and lower SOFA. High flow nasal cannula was more frequently used during the second wave (68% vs. 39%, P<0.001) and intubation was less frequent (46% vs. 69%, P<0.001). Neither 28-day mortality (30% vs. 26%, P = 0.12) nor hospital mortality (37% vs. 31%, P = 0.27) differed between first and second wave. Overweight and obesity were associated with lower 28-day mortality while older age, underlying chronic kidney disease, severity at ICU admission as assessed by SOFA score and ICU strain were associated with higher 28-day mortality. ICU strain was not associated with hospital mortality.ConclusionThe characteristics and the management of patients varied between the first and the second wave of the pandemic. Rather than the wave, ICU strain was independently associated with 28-day mortality, but not with hospital mortality.

Shortages and Vulnerabilities of Hospital Oxygen Systems.

The COVID-19 pandemic has inundated hospitals with patients suffering from profound hypoxemia and placed a strain on health care systems around the world. Shortages of personnel, drugs, ventilators, and beds were predicted and, in many cases, came to fruition. As the pandemic wore on, there have been reports of impacts on hospital medical gas supply systems. Oxygen in particular has been a concern for hospitals in terms of supply and distribution. This article outlines procedures for estimating medical gas flow limitations within health care organizations and also methods for estimating gas consumption.

Successful Recovery with Venovenous ECMO for ARDS After LVAD HeartMate 3 Implantation: A Case Report

<h3>Introduction</h3> ARDS following LVAD implantation is an unusual but devastating complication. Venovenous (VV) extracorporeal membrane oxygenation (ECMO) can be used as a salvage treatment. We report the successful use of VV ECMO for ARDS Klebsiella pneumonia following urgent LVAD Heartmate 3 implantation. <h3>Case Report</h3> A 69-year-old male with past medical history significant for ischemic cardiomyopathy, status post CABG, and with known CHF presented to the emergency department after a witnessed cardiac arrest. He was found to have a wide-complex tachycardia and his internal cardiac defibrillator discharged. He was started on intravenous lidocaine which was transitioned to amiodarone and carvedilol. An echo demonstrated an EF of 10-15% and a dilated left ventricle. Left and right heart catheterization showed a patent LIMA to LAD bypass graft and a cardiac index of 1.64 L/min/m². The patient was optimized and underwent urgent LVAD Heartmate 3 implantation (HM3, Abbott, Chicago, IL). Post-operatively he was on 20 (ppm) inhaled nitric oxide (iNO) which was weaned and he was extubated on postoperative day 2 but subsequently re-intubated on the same day due to profound hypoxemia. On post-operative day 3 the hypoxemia was refractory despite maximal ventilator support with FiO2 100%, PIP 37, PEEP 13, 20 ppm iNO. The arterial blood gas (ABG) was a pH 7.4, pO2 54, pCO2 38, HCO3 24, BE -1,and the decision was made to cannulate for VV ECMO. The patient was cannulated with a dual-lumen cannula (Avalon Elite, Getinge, Gothenburg, Sweden) in the right internal jugular vein. Respiratory cultures were positive for Klebsiella aerogenes and the patient was treated with vancomycin and cefepime. He was supported with VV ECMO for 6 days then decannulated. Two days later, a percutaneous tracheostomy was performed and he was ambulating the halls. The tracheostomy was removed after 18 days. He was discharged to a rehab facility on post-operative day 18 where he stayed for 6 days. <h3>Summary</h3> When the ventilator is at maximal settings, with minimal changes in oxygenation, VV ECMO is the next step of care for otherwise appropriate candidates. Our case demonstrates that the use of VV ECMO is a successful treatment option for a patient with refractory hypoxemia, post-cardiotomy, s/p LVAD implantation. A multi-disciplinary approach along with early initiation of these interventions can result in successful weaning of VV ECMO.

A low-cost, highly functional, emergency use ventilator for the COVID-19 crisis.

Respiratory failure complicates most critically ill patients with COVID-19 and is characterized by heterogeneous pulmonary parenchymal involvement, profound hypoxemia and pulmonary vascular injury. The high incidence of COVID-19 related respiratory failure has exposed critical shortages in the supply of mechanical ventilators, and providers with the necessary skills to treat. Traditional mass-produced ventilators rely on an internal compressor and mixer to moderate and control the gas mixture delivered to a patient. However, the current emergency has energized the pursuit of alternative designs, enabling greater flexibility in supply chain, manufacturing, storage, and maintenance considerations. To achieve this, we hypothesized that using the medical gasses and flow interruption strategy would allow for a high performance, low cost, functional ventilator. A low-cost ventilator designed and built-in accordance with the Emergency Use guidance from the US Food and Drug Administration (FDA) is presented wherein pressurized medical grade gases enter the ventilator and time limited flow interruption determines the ventilator rate and tidal volume. This simple strategy obviates the need for many components needed in traditional ventilators, thereby dramatically shortening the time from storage to clinical deployment, increasing reliability, while still providing life-saving ventilatory support. The overall design philosophy and its applicability in this new crisis is described, followed by both bench top and animal testing results used to confirm the precision, safety and reliability of this low cost and novel approach to mechanical ventilation. The ventilator meets and exceeds the critical requirements included in the FDA emergency use guidelines. The ventilator has received emergency use authorization from the FDA.

Pulmonary surfactant and COVID-19: A new synthesis.

COVID-19 pathogenesis poses paradoxes difficult to explain with traditional physiology. For instance, since type II pneumocytes are considered the primary cellular target of SARS-CoV-2; as these produce pulmonary surfactant (PS), the possibility that insufficient PS plays a role in COVID-19 pathogenesis has been raised. However, the opposite of predicted high alveolar surface tension is found in many early COVID-19 patients: paradoxically normal lung volumes and high compliance occur, with profound hypoxemia. That 'COVID anomaly' was quickly rationalised by invoking traditional vascular mechanisms-mainly because of surprisingly preserved alveolar surface in early hypoxemic cases. However, that quick rejection of alveolar damage only occurred because the actual mechanism of gas exchange has long been presumed to be non-problematic, due to diffusion through the alveolar surface. On the contrary, we provide physical chemical evidence that gas exchange occurs by an process of expansion and contraction of the three-dimensional structures of PS and its associated proteins. This view explains anomalous observations from the level of cryo-TEM to whole individuals. It encompasses results from premature infants to the deepest diving seals. Once understood, the COVID anomaly dissolves and is straightforwardly explained as covert viral damage to the 3D structure of PS, with direct treatment implications. As a natural experiment, the SARS-CoV-2 virus itself has helped us to simplify and clarify not only the nature of dyspnea and its relationship to pulmonary compliance, but also the fine detail of the PS including such features as water channels which had heretofore been entirely unexpected. For a long time, physical, colloid and surface chemistry have not intersected with physiology and cell biology as much as we might have hoped. The reasons are starting to become clear. The discipline of physical chemistry suffered from serious unrecognised omissions that rendered it ineffective. These foundational defects included omission of specific ion molecular forces and hydration effects. The discipline lacked a predictive theory of self-assembly of lipids and proteins. Worse, theory omitted any role for dissolved gases, O2, N2, CO2, and their existence as stable nanobubbles above physiological salt concentration. Recent developments have gone some way to explaining the foam-like lung surfactant structures and function. It delivers O2/N2 as nanobubbles, and efflux of CO2, and H2O nanobubbles at the alveolar surface. Knowledge of pulmonary surfactant structure allows an explanation of the mechanism of corona virus entry, and differences in infectivity of different variants. CO2 nanobubbles, resulting from metabolism passing through the molecular frit provided by the glycocalyx of venous tissue, forms the previously unexplained foam which is the endothelial surface layer. CO2 nanobubbles turn out to be lethal to viruses, providing a plausible explanation for the origin of 'Long COVID'. Circulating nanobubbles, stable above physiological 0.17 M salt drive various enzyme-like activities and chemical reactions. Awareness of the microstructure of Pulmonary Surfactant and that nanobubbles of (O2/N2) and CO2 are integral to respiratory and circulatory physiology provides new insights to the COVID-19 and other pathogen activity.

Outcome and Risk Factors of Febrile Episodes Treated with Broad Spectrum Antibiotics and Polyclonal IgM–Enriched Immunoglobulin in Pediatric Oncology Hematology Patients: A Retrospective Study

Abstract Objective Preparations with high-titer immunoglobulin-M (HT-IgM) have been used to treat neonatal and adult sepsis as adjuvant to antibiotics. Limited data are available of this use in pediatric oncohematological patients. We retrospectively assessed the characteristics and outcome of febrile episodes treated with broad-spectrum antibiotics and HT-IgM. Methods This study included febrile episodes diagnosed after chemotherapy or hematopoietic stem cell transplantation (HSCT) treated with antibiotics and HT-IgM. Study period was from January 2011 to March 2019. Results Seventy febrile episodes in 63 patients were eligible. In 40% of episodes (n = 28), blood cultures identified a causative organism: Gram-negative (n = 15), Gram-positive (n = 8), polybacterial (n = 4), fungi (n = 1). Twenty-six percent of Gram-negatives were extend spectrum β-lactamase (ESBL)-producers. In 44% of episodes, a deep-organ localization was present, mostly pulmonary. Severe or profound neutropenia, hypotension, and hypoxemia were present in 89, 26, and 21% of episodes, respectively; 20% of episodes required intensive care and 20% of episodes required the use of inotropes. Overall, 90-day mortality was 13% and infection-attributable mortality resulted 8.6%. More than half of the patients received HT-IgM within 24 hours from fever onset. HT-IgM-related allergic reactions occurred in three episodes. Risk factors for 90-day mortality were as follows: hypotension and hypoxemia at fever presentation, admission to intensive care unit (ICU), use of inotropes, presence of deep-organ infection, and escalation of antibiotic therapy within 5 days. Conclusion The combination of broad-spectrum antibiotics and HT-IgM was feasible, tolerated, and promising, being associated with a limited infectious mortality. Further prospective controlled studies are needed to assess the efficacy of this combination over a standard antibiotic approach.

Silent Hypoxia in COVID-19: A Case Series

Background: The coronavirus disease 2019 (COVID-19) pandemic is an ongoing global crisis challenging the worldwide healthcare systems. Many patients present with a mismatch of profound hypoxemia and few signs of respiratory distress (i.e., silent hypoxemia). This particular clinical presentation is often cited, but data are limited. Main Body: We describe dyspnea sensation as assessed by using the BORG scale in pulmonary patients admitted to the emergency room during a 4-week period and transferred to the respiratory department of Siloah Hospital, Hannover, Germany. From October 1 to November 1, 2020, 82 patients with hypoxemia defined as oxygen demand to achieve an oxygen saturation (SpO₂) ≥92% were included. In 45/82 (55%) patients, SARS-CoV-2 was detected by PCR on admission. Among non-COVID patients, exacerbation of COPD was the main diagnosis (15/37, 41%). All subjects rated their perceived dyspnea using the modified Borg CR10 scale. Patients in the non-COVID group suffered from more dyspnea on the modified Borg CR10 scale (median 1, IQR: 0–2 vs. median 5, IQR: 3–6, p < 0.001). In multivariate analysis, “silent hypoxemia” as defined by the dyspnea Borg CR10 scale ≥5 was independently associated with COVID-19 and presence of severe hypocapnia with an odds ratio of 0.221 (95% confidence interval 0.054, 0.907, p 0.036). Conclusion: Among pulmonary patients with acute hypoxemia defined as oxygen demand, patients suffering from COVID-19 experience less dyspnea compared to non-COVID patients. “Silent” hypoxemia was more common in COVID-19 patients.

Mechanical Ventilation during Extracorporeal Membrane Oxygenation in Acute Respiratory Distress Syndrome: A Narrative Review.

Acute respiratory distress syndrome (ARDS) is a life-threatening condition involving acute hypoxemic respiratory failure. Mechanical ventilation remains the cornerstone of management for ARDS; however, potentially injurious mechanical forces introduce the risk of ventilator-induced lung injury, multiple organ failure, and death. Extracorporeal membrane oxygenation (ECMO) is a salvage therapy aimed at ensuring adequate gas exchange for patients suffering from severe ARDS with profound hypoxemia where conventional mechanical ventilation has failed. ECMO allows for lower tidal volumes and airway pressures, which can reduce the risk of further lung injury, and allow the lungs to rest. However, the collateral effect of ECMO should be considered. Recent studies have reported correlations between mechanical ventilator settings during ECMO and mortality. In many cases, mechanical ventilation settings should be tailored to the individual; however, researchers have yet to establish optimal ventilator settings or determine the degree to which ventilation load can be decreased. This paper presents an overview of previous studies and clinical trials pertaining to the management of mechanical ventilation during ECMO for patients with severe ARDS, with a focus on clinical findings, suggestions, protocols, guidelines, and expert opinions. We also identified a number of issues that have yet to be adequately addressed.

POINT-OF-CARE ECHOCARDIOGRAPHY IN PRONE PATIENTS ON MECHANICAL VENTILATION: A PROSPECTIVE CASE SERIES

TOPIC: Imaging TYPE: Original Investigations PURPOSE: Point-of-care echocardiography plays an important role in evaluating critically ill patients admitted to the intensive care unit (ICU). Obtainable hemodynamic data has shown to be helpful in differentiating between different types of shocks and guiding management. However, this tool was frequently limited in the current COVID-19 pandemic due to the increasing number of critically ill patients requiring prone positioning for profound hypoxemia. Current literature has limited data regarding feasibility and utility of Point-of-Care Echocardiography in prone patients. METHODS: This a prospective case series involving a total of 21 patients with acute respiratory failure in the setting of COVID-19 pneumonia, requiring mechanical ventilation and prone-positioning, who were randomly enrolled over 4 months period. All patients underwent a bedside echocardiogram to visualize the apical four-chamber and five-chamber views, with the goal of assessing left ventricular function, right ventricular function and right ventricular size. The view was obtained with placing the phased array probe below the left nipple with the transducer indicator pointing toward patient left shoulder followed by moving the probe medially and laterally to obtain the best view. All images were reviewed by an independent board-certified cardiologist to assess quality and interpretability of images. RESULTS: Total of 21 patients were randomly included over a period of 4 months. Mean age was 56 years old with equal gender distribution (male 52%) and median BMI of 21 (IQR 24.8-37.8). Majority patients were ventilated with assist control/volume control mode with median PEEP of 12 (IQR 10-14) and tidal volume of 6 cc/Kg (IQR 6-7.5). LV function was normal in 14/21 (66%), decreased in 5/21 (23%), and unobtainable 2/21 (10%). Right ventricular function was normal on 14/21 (66%), decreased in 4/21 (19%), unobtainable 3/21 (14%). Median VTI was 18.9 (SD + 6.3), mean TAPSE was 17.6 (SD +6), median E/E’ 6.25 (IQR 5-8). 19/21 images were available for review by cardiology. Out of those, 12/19 (63%) scans considered of an adequate image quality and interpretability. While no difference in images quality noted between genders, a BMI of 35 and more significantly correlated with poor images [4/5 (80%) vs. 3/11 (21%);p=0.01]. In addition, left lateral prone positioning was more likely to be associated with adequate quality 5/6 (83%) as compared to other positions 6/11 (54%). CONCLUSIONS: Point-of-care echocardiography to obtain apical cardiac views is feasible in certain prone patients and can be optimized by left lateral positioning. Further studies are needed to explore and standardize the role of echocardiography in patients requiring prolonged proning. CLINICAL IMPLICATIONS: Point-of-care echocardiography can be adequate enough to provide valuable quantitative and qualitative hemodynamic data in critically ill proned patients. DISCLOSURES: No relevant relationships by Yaser Dawod, source=Web Response No relevant relationships by Benjamin Kenigsberg, source=Web Response No relevant relationships by Syed Nazeer Mahmood, source=Web Response No relevant relationships by Anantha Mallia, source=Web Response

Non‐cardiogenic pulmonary oedema and multisystemic haemorrhage secondary to an accidental intravenous injection of melarsomine in a dog

AbstractAn 8‐month‐old female entire Labradoodle was referred for further management of severe non‐cardiogenic pulmonary oedema after an accidental intravenous injection of the arsenical compound melarsomine. On arrival, the dog was non‐ambulatory, obtunded and in severe respiratory distress. Due to profound hypoxaemia despite oxygen supplementation, the dog was intubated and mechanically ventilated. While anaesthetised, the dog experienced three episodes of cardiac arrest with return of spontaneous circulation after cardiopulmonary resuscitation. However, due to continued severe hypoxaemia and haemodynamic instability, euthanasia was elected by the owners. On necropsy, marked pulmonary oedema and haemorrhage into multiple organs, including the endocardium and brain, were identified. Although no other reports describe the consequences of intravenous melarsomine in dogs, the postmortem findings are very similar to intravenous arsenic toxicity in humans. Furthermore, this case report highlights the importance of accurate drug labelling.

Case Report: Endothelial Glycocalyx Damage in Critically ill Patients With SARS-CoV-2-Related Multisystem Inflammatory Syndrome (MIS-C)

Endothelial insult and damage is one of the reported consequences of SARS-CoV-2 infection. It has been associated with severe inflammation, thrombotic phenomena and profound hypoxemia in critically ill patients. Endothelial activation leads to a loss of the endothelium's antithrombotic properties which, under normal conditions, are maintained by the endothelial glycocalyx, a carbohydrate-rich layer that covers the luminal surface of endothelial cells. In children, one of the serious forms of SARS-CoV-2 virus disease (COVID-19) is multisystem inflammatory syndrome (MIS-C). This new disease is characterized by a large inflammatory response and frequent cardiovascular, cutaneous and gastrointestinal disorders. We describe the first two cases of critically ill children with MIS-C who evidenced a large inflammatory response associated with elevated plasma and imaging biomarkers of endothelial activation and endothelial glycocalyx degradation. This microcirculation involvement in MIS-C could, at least partially, explain some of the clinical manifestations and laboratory and imaging alterations found in these patients. These findings contribute to a better understanding of this disease and suggest that medications to modulate the inflammatory response and protect or restore the endothelial glycocalyx should be considered in future studies.