Exploring Brain and Heart Interactions during Electroconvulsive Therapy with Point-of-Care Ultrasound

BACKGROUND

Electroconvulsive therapy (ECT) is a procedure commonly used to treat a number of severe psychiatric disorders, including pharmacologic refractory depression, mania, and catatonia by purposefully inducing a generalized seizure that results in significant hemodynamic changes as a result of an initial transient parasympathetic response that is followed by a marked sympathetic response from a surge in catecholamine release. While the physiologic response of ECT on classic hemodynamic parameters such as heart rate and blood pressure has been described in the literature, real-time visualization of cardiac function using point-of-care ultrasound (POCUS) during ECT has never been reported. This study utilizes POCUS to examine cardiac function in two patients with different ages and cardiovascular risk profiles undergoing ECT.

METHODS

Two patients, a 74-year-old male with significant cardiovascular risks and a 23-year-old female with no significant cardiovascular risks presenting for ECT treatment, were included in this study. A portable ultrasound device was used to obtain apical four-chamber images of the heart before ECT stimulation, after seizure induction, and 2 min after seizure resolution to assess qualitative cardiac function. Two physicians with expertise in echocardiography reviewed the studies. Hemodynamic parameters, ECT settings, and seizure duration were recorded.

RESULTS

Cardiac standstill was observed in both patients during ECT stimulation. The 74-year-old patient with a significant cardiovascular risk profile exhibited a transient decline in cardiac function during ECT, while the 23-year-old patient showed no substantial worsening of cardiac function. These findings suggest that age and pre-existing cardiovascular conditions may influence the cardiac response to ECT. Other potential contributing factors to the cardiac effects of ECT include the parasympathetic and sympathetic responses, medication regimen, and seizure duration with ECT. This study also demonstrates the feasibility of using portable POCUS for real-time cardiac monitoring during ECT.

CONCLUSION

This study reports for the first time cardiac standstill during ECT stimulation visualized using POCUS imaging. In addition, it reports on the potential differential impact of ECT on cardiac function based on patient-specific factors such as age and cardiovascular risks that may have implications for ECT and perioperative anesthetic management and optimization.

Bedside Ultrasound: The Silent Guardian for Upper Airway Assessment and Management

Ultrasound evaluation of the upper airway has emerged as an essential instrument for clinicians, offering real-time assessment that can help to guide interventions and improve patient outcomes. This review aims to provide health care providers with a practical approach to performing ultrasound evaluation of the upper airway, covering basic physics relevant to upper airway ultrasound, the identification of key anatomical structures, and elucidating its various clinical applications, such as prediction of difficult airway, confirmation of endotracheal intubation, and guidance for surgical airway procedures and airway blocks. We also discuss evidence-based training programs, limitations, and future directions of ultrasound imaging of the upper airway.

Obesity and Extracorporeal Membrane Oxygenation (ECMO): Analysis of Outcomes

Traditionally, patients with obesity have been deemed ineligible for extracorporeal life support (ELS) therapies such as extracorporeal membrane oxygenation (ECMO), given the association of obesity with chronic health conditions that contribute to increased morbidity and mortality. Nevertheless, a growing body of literature suggests the feasibility, efficacy, and safety of ECMO in the obese population. This review provides an in-depth analysis of the current literature assessing the effects of obesity on outcomes among patients supported with ECMO (venovenous [VV] ECMO in noncoronavirus disease 2019 and coronavirus disease 2019 acute respiratory distress syndrome, venoarterial [VA] ECMO, and combined VV and VA ECMO), offer a possible explanation of the current findings on the basis of the obesity paradox phenomenon, provides a framework for future studies addressing the use of ELS therapies in the obese patient population, and provides guidance from the literature for many of the challenges related to initiating, maintaining, and weaning ELS therapy in patients with obesity.

Pronation Reveals a Heterogeneous Response of Global and Regional Respiratory Mechanics in Patients With Acute Hypoxemic Respiratory Failure

OBJECTIVES

Experimental models suggest that prone position and positive end-expiratory pressure (PEEP) homogenize ventral-dorsal ventilation distribution and regional respiratory compliance. However, this response still needs confirmation on humans. Therefore, this study aimed to assess the changes in global and regional respiratory mechanics in supine and prone positions over a range of PEEP levels in acute respiratory distress syndrome (ARDS) patients.

DESIGN

A prospective cohort study.

PATIENTS

Twenty-two intubated patients with ARDS caused by COVID-19 pneumonia.

INTERVENTIONS

Electrical impedance tomography and esophageal manometry were applied during PEEP titrations from 20 cm H2O to 6 cm H2O in supine and prone positions.

MEASUREMENTS

Global respiratory system compliance (Crs), chest wall compliance, regional lung compliance, ventilation distribution in supine and prone positions.

MAIN RESULTS

Compared with supine position, the maximum level of Crs changed after prone position in 59% of ARDS patients (n = 13), of which the Crs decreased in 32% (n = 7) and increased in 27% (n = 6). To reach maximum Crs after pronation, PEEP was changed in 45% of the patients by at least 4 cm H2O. After pronation, the ventilation and compliance of the dorsal region did not consistently change in the entire sample of patients, increasing specifically in a subgroup of patients who showed a positive change in Crs when transitioning from supine to prone position. These combined changes in ventilation and compliance suggest dorsal recruitment postpronation. In addition, the subgroup with increased Crs postpronation demonstrated the most pronounced difference between dorsal and ventral ventilation distribution from supine to prone position (p = 0.01), indicating heterogeneous ventilation distribution in prone position.

CONCLUSIONS

Prone position modifies global respiratory compliance in most patients with ARDS. Only a subgroup of patients with a positive change in Crs postpronation presented a consistent improvement in dorsal ventilation and compliance. These data suggest that the response to pronation on global and regional mechanics can vary among ARDS patients, with some patients presenting more dorsal lung recruitment than others.

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.

An Assessment of Carotid Flow Time Using a Portable Handheld Ultrasound Device: The Ideal Tool for Guiding Intraoperative Fluid Management?

Volume resuscitation is a cornerstone of modern anesthesia care. Finding the right balance to avoid inadequate or excess volume administration is often difficult to clinically discern and can lead to negative consequences. Pulse pressure variation is often intraoperatively used to guide volume resuscitation; however, this requires an invasive arterial line and is generally only applicable to patients who are mechanically ventilated. Unfortunately, without a pulmonary artery catheter or another costly noninvasive device, performing serial measurements of cardiac output is challenging, time-consuming, and often impractical. Furthermore, noninvasive measures such as LVOT VTI require significant technical expertise as well as access to the chest, which may not be practical during and after surgery. Other noninvasive techniques such as bioreactance and esophageal Doppler require the use of costly single-use sensors. Here, we present a case report on the use of corrected carotid flow time (ccFT) from a portable, handheld ultrasound device as a practical, noninvasive, and technically straightforward method to assess fluid responsiveness in the perioperative period, as well as the inpatient and outpatient settings.

Design and Implementation of Airway Response Teams to Improve the Practice of Emergency Airway Management

Emergency airway management (EAM) is a commonly performed procedure in the critical care setting. Despite clinical advances that help practitioners identify patients at risk for having a difficult airway, improved airway management tools, and algorithms that guide clinical decision-making, the practice of EAM is associated with significant morbidity and mortality. Evidence suggests that a dedicated airway response team (ART) can help mitigate the risks associated with EAM and provide a framework for airway management in acute settings. We review the risks and challenges related to EAM and describe strategies to improve patient care and outcomes via implementation of an ART.

Portable Handheld Point-of-Care Ultrasound for Detecting Unrecognized Esophageal Intubations

Esophageal intubations are not an uncommon occurrence in prehospital settings, occurring as high as 17%. These "never events" are associated with significant morbidity and mortality especially when unrecognized or when there is delayed recognition. Here, we review the currently available techniques for confirming endotracheal tube intubation and their limitations, and present the case for the application of portable handheld point-of-care ultrasound as an emerging technology for detection of potentially unrecognized esophageal intubations such as during cardiac arrest. We also provide algorithms for confirmation of tracheal intubation.

Severe COVID pneumonia and undetectable B cells after vaccination in patients previously treated with rituximab: a case series

INTRODUCTION

The risk of developing severe COVID-19 illness despite completing vaccination for patients who have previously received immunosuppressive therapy is unclear.

CASE PRESENTATION

We present three patients who received rituximab for treatment of autoimmune disorders who subsequently developed severe COVID-19 pneumonia post-vaccination requiring intensive care unit admission and found to have undetectable B cells.

DISCUSSION

While there have been concerns about the effectiveness of COVID-19 vaccines in this patient cohort, this is the first case series to report development of severe COVID-19 illness after completing vaccination in those who previously received rituximab. Guidelines for the optimal timing of COVID-19 vaccination in relation to immunosuppressive therapy have been recently published, albeit after many patients in this subpopulation have already been vaccinated.

CONCLUSION

This case series brings attention to the limited humoral response to vaccines in patients treated with rituximab, highlights existing guidelines and their limitations, and raises future considerations about the potential benefits to testing vaccine responsiveness.

Noninvasive respiratory support for COVID-19 patients: when, for whom, and how?

The significant mortality rate and prolonged ventilator days associated with invasive mechanical ventilation (IMV) in patients with severe COVID-19 have incited a debate surrounding the use of noninvasive respiratory support (NIRS) (i.e., HFNC, CPAP, NIV) as a potential treatment strategy. Central to this debate is the role of NIRS in preventing intubation in patients with mild respiratory disease and the potential beneficial effects on both patient outcome and resource utilization. However, there remains valid concern that use of NIRS may prolong time to intubation and lung protective ventilation in patients with more advanced disease, thereby worsening respiratory mechanics via self-inflicted lung injury. In addition, the risk of aerosolization with the use of NIRS has the potential to increase healthcare worker (HCW) exposure to the virus. We review the existing literature with a focus on rationale, patient selection and outcomes associated with the use of NIRS in COVID-19 and prior pandemics, as well as in patients with acute respiratory failure due to different etiologies (i.e., COPD, cardiogenic pulmonary edema, etc.) to understand the potential role of NIRS in COVID-19 patients. Based on this analysis we suggest an algorithm for NIRS in COVID-19 patients which includes indications and contraindications for use, monitoring recommendations, systems-based practices to reduce HCW exposure, and predictors of NIRS failure. We also discuss future research priorities for addressing unanswered questions regarding NIRS use in COVID-19 with the goal of improving patient outcomes.

Surgical pulmonary embolectomy on VA-ECMO

Surgical pulmonary embolectomy is a procedure that is often used to rescue patients with massive pulmonary embolism (PE) and circulatory collapse that have failed or may not be ideal candidates for other systemic and endovascular treatment modalities. This procedure typically involves a sternotomy and the use of cardiopulmonary bypass (CPB), which requires full systemic anticoagulation. Here, we report the case of a surgical pulmonary embolectomy performed on venoarterial extracorporeal membrane oxygenation (VA-ECMO) rather than CPB to minimize systemic anticoagulation. The patient had suffered a cardiac arrest due to a saddle PE and required VA-ECMO which was complicated by a concomitant intracranial hemorrhage. The patient tolerated the surgical pulmonary embolectomy performed on VA-ECMO without procedure-related complications, and the ECMO support did not substantially complicate the technical performance of the procedure. In contrast to surgical pulmonary embolectomy performed on CPB, greater attention must be paid to volume status when performing the procedure on VA-ECMO since there is no blood reservoir. This case suggests cardiopulmonary support on ECMO as a viable strategy for surgical embolectomy in patients with unstable PEs in whom thrombolysis or full systemic anticoagulation are contraindicated.

Suppression of ventricular arrhythmias by targeting late L-type Ca2+ current

Ventricular arrhythmias, a leading cause of sudden cardiac death, can be triggered by cardiomyocyte early afterdepolarizations (EADs). EADs can result from an abnormal late activation of L-type Ca²⁺ channels (LTCCs). Current LTCC blockers (class IV antiarrhythmics), while effective at suppressing EADs, block both early and late components of I_Ca,L, compromising inotropy. However, computational studies have recently demonstrated that selective reduction of late I_Ca,L (Ca²⁺ influx during late phases of the action potential) is sufficient to potently suppress EADs, suggesting that effective antiarrhythmic action can be achieved without blocking the early peak I_Ca,L, which is essential for proper excitation–contraction coupling. We tested this new strategy using a purine analogue, roscovitine, which reduces late I_Ca,L with minimal effect on peak current. Scaling our investigation from a human Ca_V1.2 channel clone to rabbit ventricular myocytes and rat and rabbit perfused hearts, we demonstrate that (1) roscovitine selectively reduces I_Ca,L noninactivating component in a human Ca_V1.2 channel clone and in ventricular myocytes native current, (2) the pharmacological reduction of late I_Ca,L suppresses EADs and EATs (early after Ca²⁺ transients) induced by oxidative stress and hypokalemia in isolated myocytes, largely preserving cell shortening and normal Ca²⁺ transient, and (3) late I_Ca,L reduction prevents/suppresses ventricular tachycardia/fibrillation in ex vivo rabbit and rat hearts subjected to hypokalemia and/or oxidative stress. These results support the value of an antiarrhythmic strategy based on the selective reduction of late I_Ca,L to suppress EAD-mediated arrhythmias. Antiarrhythmic therapies based on this idea would modify the gating properties of Ca_V1.2 channels rather than blocking their pore, largely preserving contractility.

Nuts and bolts of COVID-19 associated coagulopathy: the essentials for management and treatment

INTRODUCTION

COVID-19-associated coagulopathy (CAC) is a well-recognized hematologic complication among patients with severe COVID-19 disease, where macro- and micro-thrombosis can lead to multiorgan injury and failure. Major societal guidelines that have published on the management of CAC are based on consensus of expert opinion, with the current evidence available. As a result of limited studies, there are many clinical scenarios that are yet to be addressed, with expert opinion varying on a number of important clinical issues regarding CAC management.

METHODS

In this review, we utilize current societal guidelines to provide a framework for practitioners in managing their patients with CAC. We have also provided three clinical scenarios that implement important principles of anticoagulation in patients with COVID-19.

CONCLUSION

Overall, decisions should be made on acase by cases basis and based on the providers understanding of each patient's medical history, clinical course and perceived risk.

Inhaled high dose nitric oxide is a safe and effective respiratory treatment in spontaneous breathing hospitalized patients with COVID-19 pneumonia

BACKGROUND

Inhaled nitric oxide (NO) is a selective pulmonary vasodilator. In-vitro studies report that NO donors can inhibit replication of SARS-CoV-2. This multicenter study evaluated the feasibility and effects of high-dose inhaled NO in non-intubated spontaneously breathing patients with Coronavirus disease-2019 (COVID-19).

METHODS

This is an interventional study to determine whether NO at 160 parts-per-million (ppm) inhaled for 30 min twice daily might be beneficial and safe in non-intubated COVID-19 patients.

RESULTS

Twenty-nine COVID-19 patients received a total of 217 intermittent inhaled NO treatments for 30 min at 160 ppm between March and June 2020. Breathing NO acutely decreased the respiratory rate of tachypneic patients and improved oxygenation in hypoxemic patients. The maximum level of nitrogen dioxide delivered was 1.5 ppm. The maximum level of methemoglobin (MetHb) during the treatments was 4.7%. MetHb decreased in all patients 5 min after discontinuing NO administration. No adverse events during treatment, such as hypoxemia, hypotension, or acute kidney injury during hospitalization occurred. In our NO treated patients, one patient of 29 underwent intubation and mechanical ventilation, and none died. The median hospital length of stay was 6 days [interquartile range 4-8]. No discharged patients required hospital readmission nor developed COVID-19 related long-term sequelae within 28 days of follow-up.

CONCLUSIONS

In spontaneous breathing patients with COVID-19, the administration of inhaled NO at 160 ppm for 30 min twice daily promptly improved the respiratory rate of tachypneic patients and systemic oxygenation of hypoxemic patients. No adverse events were observed. None of the subjects was readmitted or had long-term COVID-19 sequelae.

Rapid Expansion of the Airway Response Team to Meet the Needs of the COVID-19 Pandemic

INTRODUCTION

The COVID-19 pandemic has brought unprecedented numbers of patients with acute respiratory distress to medical centers. Hospital systems require rapid adaptation to respond to the increased demand for airway management while ensuring high quality patient care and provider safety. There is limited literature detailing successful system-level approaches to adapt to the surge of COVID-19 patients requiring airway management.

METHODS

A deliberate system-level approach was used to expand a preexisting airway response service. Through a needs analysis (taking into account both existing resources and anticipated demands), we established priorities and solutions for the airway management challenges encountered during the pandemic.

RESULTS

During our COVID-19 surge (March 10, 2020, through May 26, 2020), there were 619 airway consults, and the COVID airway response team (CART) performed 341 intubations. Despite a 4-fold increase in intubations during the surge, there was no increase in cardiac arrests or surgical airways and no documented COVID-19 infections among the CART.

CONCLUSIONS

Our system-level approach successfully met the sudden escalation in demand in airway management incurred by the COVID-19 surge. The approach that addressed staffing needs prioritized provider protection and enhanced quality and safety monitoring may be adaptable to other institutions.

Right Ventricular Strain Is Common in Intubated COVID-19 Patients and Does Not Reflect Severity of Respiratory Illness

BACKGROUND

Right ventricular (RV) dysfunction is common and associated with worse outcomes in patients with coronavirus disease 2019 (COVID-19). In non-COVID-19 acute respiratory distress syndrome, RV dysfunction develops due to pulmonary hypoxic vasoconstriction, inflammation, and alveolar overdistension or atelectasis. Although similar pathogenic mechanisms may induce RV dysfunction in COVID-19, other COVID-19-specific pathology, such as pulmonary endothelialitis, thrombosis, or myocarditis, may also affect RV function. We quantified RV dysfunction by echocardiographic strain analysis and investigated its correlation with disease severity, ventilatory parameters, biomarkers, and imaging findings in critically ill COVID-19 patients.

METHODS

We determined RV free wall longitudinal strain (FWLS) in 32 patients receiving mechanical ventilation for COVID-19-associated respiratory failure. Demographics, comorbid conditions, ventilatory parameters, medications, and laboratory findings were extracted from the medical record. Chest imaging was assessed to determine the severity of lung disease and the presence of pulmonary embolism.

RESULTS

Abnormal FWLS was present in 66% of mechanically ventilated COVID-19 patients and was associated with higher lung compliance (39.6 vs 29.4 mL/cmH2O, P = 0.016), lower airway plateau pressures (21 vs 24 cmH2O, P = 0.043), lower tidal volume ventilation (5.74 vs 6.17 cc/kg, P = 0.031), and reduced left ventricular function. FWLS correlated negatively with age (r = -0.414, P = 0.018) and with serum troponin (r = 0.402, P = 0.034). Patients with abnormal RV strain did not exhibit decreased oxygenation or increased disease severity based on inflammatory markers, vasopressor requirements, or chest imaging findings.

CONCLUSIONS

RV dysfunction is common among critically ill COVID-19 patients and is not related to abnormal lung mechanics or ventilatory pressures. Instead, patients with abnormal FWLS had more favorable lung compliance. RV dysfunction may be secondary to diffuse intravascular micro- and macro-thrombosis or direct myocardial damage.

TRIAL REGISTRATION

National Institutes of Health #NCT04306393. Registered 10 March 2020, https://clinicaltrials.gov/ct2/show/NCT04306393.

An examination of gastrointestinal absorption using the acetaminophen absorption test in critically ill patients with COVID-19: A retrospective cohort study

OBJECTIVE

Gastrointestinal (GI) dysfunction is prevalent in critically ill patients with coronavirus disease 2019 (COVID-19). The acetaminophen absorption test (AAT) has been previously described as a direct method for assessment of GI function. Our study determines whether the AAT can be used to assess GI function in critically ill COVID-19 patients, compared with traditional measures of GI function.

DESIGN

Retrospective observational study of critically ill patients with COVID-19.

SETTING

Three intensive care units at a tertiary care academic medical center.

PATIENTS

Twenty critically ill patients with COVID-19.

INTERVENTIONS

The results of AAT and traditional measures for assessing GI function were collected and compared.

MEASUREMENTS AND MAIN RESULTS

Among the study cohort, 55% (11 of 20) of patients had evidence of malabsorption by AAT. Interestingly, all patients with evidence of malabsorption by AAT had clinical evidence of bowel function, as indicated by stool output and low gastric residuals during the prior 24 h. When comparing patients with a detectable acetaminophen level (positive AAT) with those who had undetectable acetaminophen levels (negative AAT), radiologic evidence of ileus was less frequent (20 vs 88%; P = .03), tolerated tube-feed rates were higher (40 vs 10 ml/h; P =.01), and there was a trend toward lower gastric residual volumes (45 vs 830 ml; P =.11).

CONCLUSION

Malabsorption can occur in critically ill patients with COVID-19 despite commonly used clinical indicators of tube-feeding tolerance. The AAT provides a simple, rapid, and cost-effective mechanism by which enteral function can be efficiently assessed in COVID-19 patients.

An examination of sedation requirements and practices for mechanically ventilated critically ill patients with COVID-19

PURPOSE

Preliminary reports suggest that critically ill patients with coronavirus disease 2019 (COVID-19) infection requiring mechanical ventilation may have markedly increased sedation needs compared with non-mechanically ventilated patients. We conducted a study to examine sedative use for this patient population within multiple intensive care units (ICUs) of a large academic medical center.

METHODS

A retrospective, single-center cohort study of sedation practices for critically ill patients with COVID-19 during the first 10 days of mechanical ventilation was conducted in 8 ICUs at Massachusetts General Hospital, Boston, MA. The study population was a sequential cohort of 86 critically ill, mechanically ventilated patients with COVID-19. Data characterizing the sedative medications, doses, drug combinations, and duration of administration were collected daily and compared to published recommendations for sedation of critically ill patients without COVID-19. The associations between drug doses, number of drugs administered, baseline patient characteristics, and inflammatory markers were investigated.

RESULTS

Among the study cohort, propofol and hydromorphone were the most common initial drug combination, with these medications being used on a given day in up to 100% and 88% of patients, respectively. The doses of sedative and analgesic infusions increased for patients over the first 10 days, reaching or exceeding the upper limits of published dosage guidelines for propofol (48% of patients), dexmedetomidine (29%), midazolam (7.7%), ketamine (32%), and hydromorphone (38%). The number of sedative and analgesic agents simultaneously administered increased over time for each patient, with more than 50% of patients requiring 3 or more agents by day 2. Compared with patients requiring 3 or fewer agents, as a group patients requiring more than 3 agents were of younger age, had an increased body mass index, increased serum ferritin and lactate dehydrogenase concentrations, had a lower PaO2:FIO2 (ratio of arterial partial pressure of oxygen to fraction of inspired oxygen), and were more likely to receive neuromuscular blockade.

CONCLUSION

Our study confirmed the clinical impression of elevated sedative use in critically ill, mechanically ventilated patients with COVID-19 relative to guideline-recommended sedation practices in other critically ill populations.

Biplane Imaging Using Portable Ultrasound Devices for Vascular Access

The use of ultrasound guidance for the placement of difficult IVs, arterial lines, and central venous access has become the standard of care. While imaging quality has improved over the last two decades, the lack of affordability, availability, and training have been major limitations in its routine clinical use. We detail the first reported use of biplane imaging using a portable ultrasound probe for difficult vascular access to increase first past success, efficiency, safety, and sterility during the coronavirus disease 2019 (COVID-19) pandemic. 

Multisystem effects of COVID-19: a concise review for practitioners

While COVID-19 has primarily been characterized by the respiratory impact of viral pneumonia, it affects every organ system and carries a high consequent risk of death in critically ill patients. Higher sequential organ failure assessment (SOFA) scores have been associated with increased mortality in patients critically ill patients with COVID-19. It is important that clinicians managing critically ill COVID-19 patients be aware of the multisystem impact of the disease so that care can be focused on the prevention of end-organ injuries to potentially improve clinical outcomes. We review the multisystem complications of COVID-19 and associated treatment strategies to improve the care of critically ill COVID-19 patients.

Ensuring competency in focused cardiac ultrasound: a systematic review of training programs

BACKGROUND

Focused cardiac ultrasound (FoCUS) is a valuable skill for rapid assessment of cardiac function and volume status. Despite recent widespread adoption among physicians, there is limited data on the optimal training methods for teaching FoCUS and metrics for determining competency. We conducted a systematic review to gain insight on the optimal training strategies, including type and duration, that would allow physicians to achieve basic competency in FoCUS.

METHODS

Embase, PubMed, and Cochrane Library databases were searched from inception to June 2020. Included studies described standardized training programs for at least 5 medical students or physicians on adult FoCUS, followed by an assessment of competency relative to an expert. Data were extracted, and bias was assessed for each study.

RESULTS

Data were extracted from 23 studies on 292 learners. Existing FoCUS training programs remain varied in duration and type of training. Learners achieved near perfect agreement (κ > 0.8) with expert echocardiographers on detecting left ventricular systolic dysfunction and pericardial effusion with 6 h each of didactics and hands-on training. Substantial agreement (κ > 0.6) on could be achieved in half this time.

CONCLUSION

A short training program will allow most learners to achieve competency in detecting left ventricular systolic dysfunction and pericardial effusion by FoCUS. Additional training is necessary to ensure skill retention, improve efficiency in image acquisition, and detect other pathologies.

Sodium-glucose cotransporter-2 (SGLT2) inhibitor-induced euglycemic diabetic ketoacidosis complicating the perioperative management of a patient with type 2 diabetes mellitus (T2DM) and Fournier's gangrene: A case report

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This case highlights two serious side effects of empagliflozin occurring concurrently. Those being diabetic ketoacidosis and Fournier’s gangrene.

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Diabetic ketoacidosis is an important cause of perioperative high anion gap metabolic acidosis in the context of SGLT2 inhibitors and needs to be carefully managed.

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SGLT2 inhibitors should be held up to 48 h prior to surgery to minimize the risk of diabetic ketoacidosis perioperatively.

Introduction

Sodium glucose cotransporter-2 inhibitors (SGLT2) are an increasingly administered class of medication used to lower blood glucose levels in patients with type 2 diabetes mellitus. Diabetic ketoacidosis (DKA) and Fournier’s gangrene are rare, but potentially catastrophic side effects of SGLT2 inhibitors. This manuscript reports a case of both DKA and Fournier’s gangrene in the context of SGLT2 inhibitor use.

Presentation of case

A 51-year-old morbidly obese man with hypertension and poorly controlled Type 2 Diabetes Mellitus presented to the emergency department with a clinical presentation consistent with Fournier’s gangrene. He was promptly taken to the operating room by the urology team where he had extensive debridement of the perineum and abdomen. Intra-operatively he was found to have DKA, which was managed appropriately. The acidosis and Fournier’s gangrene were deemed a likely side effect of SGLT2 inhibitor use. After a thirty-day hospital admission, the patient was discharged to a rehabilitation facility where he is progressing well. His SGLT2 inhibitor was discontinued upon admission to hospital.

Discussion

Perioperative providers should have a high index of suspicion for diabetic ketoacidosis (DKA) and Fournier’s gangrene in patients prescribed SGLT2 inhibitors. Prompt treatment of DKA through correction of underlying triggers, aggressive fluid resuscitation, insulin to close the anion gap, and appropriate potassium repletion is vital to optimize patient outcomes.

Conclusion

The use of SGLT2 inhibitors among surgical populations is increasing. This case highlights the importance of being aware of the mechanism and side effects of SGLT2 inhibitors, and the management of DKA.

Use of Handheld Point-of-Care Ultrasound in Emergency Airway Management

Emergency airway management (EAM) is associated with a high rate of complications, morbidity, and mortality. Handheld point-of-care ultrasound shows promise as an emerging technology to facilitate rapid screening for difficult laryngoscopy, identify the cricothyroid membrane for potential cricothyroidotomy, and assess for increased aspiration risk, as well as provide confirmation of proper endotracheal tube positioning. This review summarizes the available evidence for the use of point-of-care ultrasound in EAM, provides an algorithm to facilitate its incorporation into existing EAM practice to improve patient safety, and serves as a framework for future validation studies.

Comparison of published guidelines for management of coagulopathy and thrombosis in critically ill patients with COVID 19: implications for clinical practice and future investigations

Critically ill patients with COVID-19 are at increased risk for thrombotic complications which has led to an intense debate surrounding their anticoagulation management. In the absence of data from randomized controlled clinical trials, a number of consensus guidelines and recommendations have been published to facilitate clinical decision-making on this issue. However, substantive differences exist between these guidelines which can be difficult for clinicians. This review briefly summarizes the major societal guidelines and compares their similarities and differences. A common theme in all of the recommendations is to take an individualized approach to patient management and a call for prospective randomized clinical trials to address important anticoagulation issues in this population.

Application of Lung Ultrasound During the COVID-19 Pandemic: A Narrative Review

This review highlights the ultrasound findings reported from a number of studies and case reports and discusses the unifying findings from coronavirus disease (COVID-19) patients and from the avian (H7N9) and H1N1 influenza epidemics. We discuss the potential role for portable point-of-care ultrasound (PPOCUS) as a safe and effective bedside option in the initial evaluation, management, and monitoring of disease progression in patients with confirmed or suspected COVID-19 infection.

In-hospital airway management of COVID-19 patients

Those involved in the airway management of COVID-19 patients are particularly at risk. Here, we describe a practical, stepwise protocol for safe in-hospital airway management in patients with suspected or confirmed COVID-19 infection.

The Vacuum Assisted Negative Pressure Isolation Hood (VANISH) System: Novel Application of the Stryker Neptune™ Suction Machine to Create COVID-19 Negative Pressure Isolation Environments

Coronavirus disease 2019 (COVID-19) may remain viable in the air for up to three hours, placing health care workers in close proximity to aerosolizing procedures particularly at high risk for infection. This combined with the drastic shortage of negative pressure rooms hospitals worldwide has led to the rapid innovation of novel biohazard isolation hoods, which can be adapted to create negative pressure isolation environments around the patient's airway using the hospital wall suction, which carries many limitations, including weaker suction capabilities, single patient use, and immobility. Here, we report our Vacuum Assisted Negative Pressure Isolation Hood (VANISH) system that uses a mobile and readily available in most hospital operating rooms Stryker Neptune™ (Stryker Corporation, Kalamazoo, Michigan) high-powered suction system to more effectively create a negative pressure biohazard isolation environment. VANISH has been utilized regularly in an anesthesia practice of 30+ providers and, to date, there have been no documented COVID-19 infections.

Personal Protective Equipment N95 Facemask Shortage Quick Fix: The Modified Airway From VEntilatoR Circuit (MAVerIC)

We are in a crisis where healthcare providers on the frontlines are running out of the appropriate personal protective equipment including N95 masks and power air-purifying respirators. Here, we propose a makeshift filter mask that we call the Modified Airway from VEntilatoR Circuit (MAVerIC) that can be assembled within seconds using widely available supplies routinely utilized by anesthesia providers in the operating room to provide practitioners on the frontlines with the high standard of protection of a N95 mask during the coronavirus disease 2019 (COVID-19) pandemic, and can be easily quantitatively “fit tested” to ensure no significant leak to optimize safety and efficacy.

Pro- and antiarrhythmic effects of ATP-sensitive potassium current activation on reentry during early afterdepolarization-mediated arrhythmias

BACKGROUND

Under conditions promoting early afterdepolarizations (EADs), ventricular tissue can become bi-excitable, that is, capable of wave propagation mediated by either the Na current (INa) or the L-type calcium current (ICa,L), raising the possibility that ICa,L-mediated reentry may contribute to polymorphic ventricular tachycardia (PVT) and torsades de pointes. ATP-sensitive K current (IKATP) activation suppresses EADs, but the effects on ICa,L-mediated reentry are unknown.

OBJECTIVE

To investigate the effects of IKATP activation on ICa,L-mediated reentry.

METHODS

We performed optical voltage mapping in cultured neonatal rat ventricular myocyte monolayers exposed to BayK8644 and isoproterenol. The effects of pharmacologically activating IKATP with pinacidil were analyzed.

RESULTS

In 13 monolayers with anatomic ICa,L-mediated reentry around a central obstacle, pinacidil (50 μM) converted ICa,L-mediated reentry to INa-mediated reentry. In 33 monolayers with functional ICa,L-mediated reentry (spiral waves), pinacidil terminated reentry in 17, converted reentry into more complex INa-mediated reentry resembling fibrillation in 12, and had no effect in 4. In simulated 2-dimensional bi-excitable tissue in which ICa,L- and INa-mediated wave fronts coexisted, slow IKATP activation (over minutes) reliably terminated rotors but rapid IKATP activation (over seconds) often converted ICa,L-mediated reentry to INa-mediated reentry resembling fibrillation.

CONCLUSIONS

IKATP activation can have proarrhythmic effects on EAD-mediated arrhythmias if ICa,L-mediated reentry is present.

Bi-stable wave propagation and early afterdepolarization-mediated cardiac arrhythmias

BACKGROUND

In normal atrial and ventricular tissue, the electrical wavefronts are mediated by the fast sodium current (I(Na)), whereas in sinoatrial and atrioventricular nodal tissue, conduction is mediated by the slow L-type calcium current (I(Ca,L)). However, it has not been shown whether the same tissue can exhibit both the I(Na)-mediated and the I(Ca,L)-mediated conduction.

OBJECTIVE

This study sought to test the hypothesis that bi-stable cardiac wave conduction, mediated by I(Na) and I(Ca,L), respectively, can occur in the same tissue under conditions promoting early afterdepolarizations (EADs), and to study how this novel wave dynamics is related to the mechanisms of EAD-mediated arrhythmias.

METHODS

Computer models of two-dimensional (2D) tissue with a physiologically detailed action potential model were used to study the bi-stable wave dynamics. Theoretical predictions were tested experimentally by optical mapping in neonatal rat ventricular myocyte monolayers.

RESULTS

In the same 2D homogeneous tissue, we could induce spiral waves that are mediated by either I(Na) or I(Ca,L) under conditions in which the action potential model exhibited EADs. This bi-stable wave propagation behavior was similar to bi-stability shown in many other nonlinear systems. Because the bi-stable states are also excitable, we call this novel behavior bi-excitability. In a 2D heterogeneous tissue, the I(Ca,L)-mediated spiral wave meanders, giving rise to a twisting electrocardiographic QRS axis, resembling torsades de pointes, whereas the coexistence and interplay between the I(Na)-mediated wavefronts and I(Ca,L)-mediated wavefronts give rise to polymorphic ventricular tachycardia. We also present experimental evidence for bi-excitability under EAD-promoting conditions in neonatal rat ventricular myocyte monolayers exposed to BayK8644 and isoproterenol.

CONCLUSION

Under EAD-prone conditions, both I(Na)-mediated conduction and I(Ca,L)-mediated conduction can occur in the same tissue. These novel wave dynamics may be responsible for certain EAD-mediated arrhythmias, such as torsades de pointes and polymorphic ventricular tachycardia.

Atrioventricular conduction and arrhythmias at the initiation of beating in embryonic mouse hearts

To investigate cardiac physiology at the onset of heart beating in embryonic mouse hearts, we performed optical imaging of membrane potential (Vm) and/or intracellular calcium (Ca(i)). Action potentials and Ca(i) transients were detected in approximately 50% of mouse embryo hearts at E8.5, but in all hearts at E9.0, indicating that beating typically starts between E8-E9. Beating was eliminated by Ca channel blocker nifedipine and the I(f) blocker ZD7288, unaffected by tetrodotoxin and only mildly depressed by disabling sarcoplasmic (SR) and endoplasmic (ER) reticulum Ca cycling. From E8.5 to E10, conduction velocity increased from 0.2-1 mm/s to >5 mm/s in first ventricular and then atrial tissue, while remaining slow in other areas. Arrhythmias included atrioventricular reentry induced by adenosine. In summary, at the onset of beating, I(f)-dependent pacemaking drives both AP propagation and Ca(i) transient generation through activation of voltage-dependent Ca channels. Na channels and intracellular Ca cycling have minor roles.

Spiral waves and reentry dynamics in an in vitro model of the healed infarct border zone

RATIONALE

Reentry underlies most ventricular tachycardias (VTs) seen postmyocardial infarction (MI). Mapping studies reveal that the majority of VTs late post-MI arise from the infarct border zone (IBZ).

OBJECTIVE

To investigate reentry dynamics and the role of individual ion channels on reentry in in vitro models of the "healed" IBZ.

METHODS AND RESULTS

We designed in vitro models of the healed IBZ by coculturing skeletal myotubes with neonatal rat ventricular myocytes and performed optical mapping at high temporal and spatial resolution. In culture, neonatal rat ventricular myocytes mature to form striated myocytes and electrically uncoupled skeletal myotubes simulate fibrosis seen in the healed IBZ. High resolution mapping revealed that skeletal myotubes produced localized slowing of conduction velocity (CV), increased dispersion of CV and directional-dependence of activation delay without affecting myocyte excitability. Reentry was easily induced by rapid pacing in cocultures; treatment with lidocaine, a Na(+) channel blocker, significantly decreased reentry rate and CV, increased reentry path length and terminated 30% of reentrant arrhythmias (n=18). In contrast, nitrendipine, an L-type Ca(2+) channel blocker terminated 100% of reentry episodes while increasing reentry cycle length and path length and decreasing reentry CV (n=16). K(+) channel blockers increased reentry action potential duration but infrequently terminated reentry (n=12).

CONCLUSIONS

Cocultures reproduce several architectural and electrophysiological features of the healed IBZ. Reentry termination by L-type Ca(2+) channel, but not Na(+) channel, blockers suggests a greater Ca(2+)-dependence of propagation. These results may help explain the low efficacy of pure Na(+) channel blockers in preventing and terminating clinical VTs late after MI.

Region of slowed conduction acts as core for spiral wave reentry in cardiac cell monolayers

Pathophysiological heterogeneity in cardiac tissue is related to the occurrence of arrhythmias. Of importance are regions of slowed conduction, which have been implicated in the formation of conduction block and reentry. Experimentally, it has been a challenge to produce local heterogeneity in a manner that is both reversible and well controlled. Consequently, we developed a dual-zone superfusion chamber that can dynamically create a small (5 mm) central island of heterogeneity in cultured cardiac cell monolayers. Three different conditions were studied to explore the effect of regionally slowed conduction on wave propagation and reentry: depolarization by elevated extracellular potassium, sodium channel inhibition with lidocaine, and cell-cell decoupling with palmitoleic acid. Using optical mapping of transmembrane voltage, we found that the central region of slowed conduction always served as the core region around which a spiral wave formed and then revolved following a period of rapid pacing. Because of the localized slowing in the core region, we observed experimentally for the first time an S shape of the spiral wave front near its tip. These results indicate that a small region of slowed conduction can play a crucial role in the formation, anchoring, and modulation of reentrant spiral waves.

Proarrhythmic Potential of Mesenchymal Stem Cell Transplantation Revealed in an In Vitro Coculture Model

Background— Mesenchymal stem cells (MSCs) are bone marrow stromal cells that are in phase 1 clinical studies of cellular cardiomyoplasty. However, the electrophysiological effects of MSC transplantation have not been studied. Although improvement of ventricular function would represent a positive outcome of MSC transplantation, focal application of stem cells has the potential downside of creating inhomogeneities that may predispose the heart to reentrant arrhythmias. In the present study we use an MSC and neonatal rat ventricular myocyte (NRVM) coculture system to investigate potential proarrhythmic consequences of MSC transplantation into the heart.

Methods and Results— Human MSCs were cocultured with NRVMs in ratios of 1:99, 1:9, and 1:4 and optically mapped. We found that conduction velocity was decreased in cocultures compared with controls, but action potential duration (APD 80 ) was not affected. Reentrant arrhythmias were induced in 86% of cocultures containing 10% and 20% MSCs (n=36) but not in controls (n=7) or cocultures containing only 1% MSCs (n=4). Immunostaining, Western blot, and dye transfer revealed the presence of functional gap junctions involving MSCs.

Conclusions— Our results suggest that mixtures of MSCs and NRVMs can produce an arrhythmogenic substrate. The mechanism of reentry is probably increased tissue heterogeneity resulting from electric coupling of inexcitable MSCs with myocytes.

Antiarrhythmic engineering of skeletal myoblasts for cardiac transplantation

Skeletal myoblasts are an attractive cell type for transplantation because they are autologous and resistant to ischemia. However, clinical trials of myoblast transplantation in heart failure have been plagued by ventricular tachyarrhythmias and sudden cardiac death. The pathogenesis of these arrhythmias is poorly understood, but may be related to the fact that skeletal muscle cells, unlike heart cells, are electrically isolated by the absence of gap junctions. Using a novel in vitro model of myoblast transplantation in cardiomyocyte monolayers, we investigated the mechanisms of transplant-associated arrhythmias. Cocultures of human skeletal myoblasts and rat cardiomyocytes resulted in reentrant arrhythmias (spiral waves) that reproduce the features of ventricular tachycardia seen in patients receiving myoblast transplants. These arrhythmias could be terminated by nitrendipine, an l-type calcium channel blocker, but not by the Na channel blocker lidocaine. Genetic modification of myoblasts to express the gap junction protein connexin43 decreased arrhythmogenicity in cocultures, suggesting a specific means for increasing the safety (and perhaps the efficacy) of myoblast transplantation in patients.