Simulation of Aerosol and Droplet Spread during Upper Airway and Gastrointestinal Endoscopy.

BACKGROUND AND AIMS: Aerosols and droplets are the main vectors in transmission of highly contagious SARS-CoV-2. Invasive diagnostic procedures like upper airway and gastrointestinal endoscopy have been declared as aerosol-generating procedures. Protection of healthcare workers is crucial in times of the COVID-19 pandemic. METHODS: We simulated aerosol and droplet spread during upper airway and gastrointestinal endoscopy with and without physico-mechanical barriers using a simulation model. RESULTS: A clear plastic drape as used for central venous access markedly reduced visualized aerosol and droplet spread during endoscopy. CONCLUSION: A simple and cheap drape has the potential to reduce aerosol and droplet spread during endoscopy. In terms of healthcare worker protection, this may be important particularly in low- or moderate-income countries.

Veno-arterial-venous extracorporal membrane oxygenation (V-AV ECMO) in a patient in ARDS and cardiac instability after severe polytrauma.

The role of extracorporeal life support (ECLS) in critically ill trauma patients is underutilized, mainly due to concerns of anticoagulation. However, short-term ECLS in these patients can be safely performed with no or minimal systemic anticoagulation. Case series show favorable outcomes in trauma patients with veno-venous (V-V) and veno-arterial (V-A) ECMO, respectively, but there are only a few case reports of successful veno-arterio-venous (V-AV) ECMO in polytrauma patients. We report on a 63-year-old female admitted to our emergency department following a severe car accident who was successfully treated in a multidisciplinary approach, including bridging to damage control surgery and recovery with a V-AV ECMO.

Leg-heel chest compression as an alternative for medical professionals in times of COVID-19.

OBJECTIVE: To evaluate leg-heel chest compression without previous training as an alternative for medical professionals and its effects on distance to potential aerosol spread during chest compression. METHODS: 20 medical professionals performed standard manual chest compression followed by leg-heel chest compression after a brief instruction on a manikin. We compared percentage of correct chest compression position, percentage of full chest recoil, percentage of correct compression depth, average compression depth, percentage of correct compression rate and average compression rate between both methods. In a second approach, potential aerosol spread during chest compression was visualized. RESULTS: Our data indicate no credible difference between manual and leg-heel compression. The distance to potential aerosol spread could have been increased by leg-heel method. CONCLUSION: Under special circumstances like COVID-19-pandemic, leg-heel chest compression may be an effective alternative without previous training compared to manual chest compression while markedly increasing the distance to the patient.

Extreme Metabolic Alkalosis and Acute Kidney Injury in a 38-Year-Old Male Patient.

Repeated vomiting may lead to profound loss of fluid and electrolytes. We describe a case with life-threatening acid-base disturbances due to vomiting. A 38-year-old man presented to an emergency department with weakness and decreased urine output after having vomited up to 20 times per day over a period of 7 days. Arterial blood gas analysis revealed a metabolic alkalosis with partial respiratory compensation. Initial management consisted of oxygen therapy and intravenous fluid therapy with normal saline and potassium chloride. To prevent further gastric losses of HCl, proton-pump inhibitors and metoclopramide were administered. The vomiting was caused most likely by a temporary duodenal stenosis due to portal hypertension of unknown etiology. In our opinion, this case demonstrates the successful management of a life-threatening condition by simple measures. Despite extensive diagnostic procedures, the effective treatment of the underlying condition consisted of watchful waiting.

Beliefs, preferences, and acceptance of personal protective equipment for a shock room team in a tertiary care center.

BACKGROUND: During coronavirus disease of 2019 pandemic a standard usage of personal protective equipment (PPE) in healthcare was mandatory, while actually the usage of PPE is currently decreasing. This raises the question about the further use of PPE in the clinical setting because healthcare workers (HCW) are at greater risk of being infected with SARS-CoV-2 than the general population. The primary objective of this study is to determine the proportion of shock room team members approving the further use of PPE including a FFP2 respirator in simulation training and reality. The secondary objectives are to describe the expertise and difficulties faced while using PPE in the shock room care. METHODS: Fifty-four HCW participated in a shock room simulation training at a large urban tertiary care hospital in Germany, utilizing a PPE comprising an FFP2 mask, gloves, goggles, and gown. Subsequently, participants completed an online questionnaire featuring 15 questions presented on a 5-point Likert scale or as multiple-choice questions with predefined answers. RESULTS: Sixty-eight point five percent of our participants voted for an established standard PPE in shock room care. The largest fraction of our participants (40.7%) favors a standard PPE consisting of FFP2 mask, gown, and gloves. Less HCW (31.5%) want to wear PPE in shock room simulation training. Except for goggles we could not detect relevant difficulties faced while using PPE in the shock room environment. Incorrect use of PPE was observed in 14.8%. CONCLUSION: A majority of our participants favored a standard PPE including a FFP2 respirator in shock room care. In addition, we recommend the use of PPE in shock room simulation training, while further awareness of and training in proper use of PPE seems to be necessary to reduce risk of infectious diseases for HCW.

New echocardiographic findings correlate with intramyocardial inflammation in endomyocardial biopsies of patients with acute myocarditis and inflammatory cardiomyopathy.

BACKGROUND: The diagnosis of acute myocarditis (AMC) and inflammatory cardiomyopathy (DCMi) can be difficult. Speckle tracking echocardiography with accurate assessments of regional contractility could have an outstanding importance for the diagnosis. METHODS AND RESULTS: N = 25 patients with clinically diagnosed AMC who underwent endomyocardial biopsies (EMBs) were studied prospectively. Speckle tracking imaging was examined at the beginning and during a mean follow-up period of 6.2 months. In the acute phase patients had markedly decreased left ventricular (LV) systolic function (mean LV ejection fraction (LVEF) 40.4 ± 10.3%). At follow-up in n = 8 patients, inflammation persists, correlating with a significantly reduced fractional shortening (FS, 21.5 ± 6.0%) in contrast to those without inflammation in EMB (FS 32.1 ± 7.1%, P < 0.05). All AMC patients showed a reduction in global systolic longitudinal strain (LS, -8.36 ± -3.47%) and strain rate (LSR, 0.53 ± 0.29 1/s). At follow-up, LS and LRS were significantly lower in patients with inflammation, in contrast to patients without inflammation (-9.4 ± 1.4 versus -16.8 ± 2.0%, P < 0.0001; 0.78 ± 0.4 versus 1.3 ± 0.3 1/s). LSR and LS correlate significantly with lymphocytic infiltrates (for CD3 r = 0.7, P < 0.0001, and LFA-1 r = 0.8, P < 0.0001). CONCLUSION: Speckle tracking echocardiography is a useful adjunctive assisting tool for evaluation over the course of intramyocardial inflammation in patients with AMC and DCMi.

Weaning assessment of veno-arteriovenous (V-AV) extracorporeal membrane oxygenation (ECMO).

Currently, there is a lack of methods for simultaneous assessment of readiness for decannulation of the veno-venous (V-V) and veno-arterial (V-A) components during veno-arteriovenous (V-AV) extracorporal membrane oxygenation (ECMO) support. We describe a novel approach using a simultaneous off-sweep and controlled backflow test to assess readiness for decannulation from V-AV ECMO. This method needs testing in future clinical trials.

Mechanisms of limitation of oxygen delivery during veno-venous extracorporal membrane oxygenation.

Delivery of oxygen to the mitochondrium is a process involving multiple steps. We here present the integration of the mechanisms of oxygen delivery (DO2) during veno-venous (V-V) extracorporal membrane oxygenation (ECMO) into a holistic physiological model. The final steps of oxygen transport in this model are the convective transport of oxygen bound to hemoglobin in the arterial blood and the diffusion to the mitochondrium from the microcirculation. Limitation of DO2 may occur on both steps. In cases of severe respiratory failure without lung function, ECMO may provide the entire oxygen supply for the patients. If the cardiac output (CO) is significantly higher than the maximal ECMO flow, the addition of deoxygenated venous blood will lead to a low arterial oxygen saturation (SaO2). In this situation the convective transport of oxygen is mostly limited by the maximal ECMO flow. If a bi-caval dual lumen cannula is used, the recirculation may be very low. Lowering the CO in this situation will increase the arterial SaO2. An increased arterial SaO2 may increase the oxygen transport to the mitochondrium by diffusion. The hypothesis derived from this model is that lowering the CO during V-V ECMO support in the situation described above might increase DO2 to the tissues by improving oxygen diffusion.

Exploration of strategies to reduce aerosol-spread during chest compressions: A simulation and cadaver model.

OBJECTIVE: To evaluate the effect of strategies to reduce the spread of simulated aerosol during chest compressions on manikin and cadaver experimental models. METHODS: To evaluate aerosol-spread we nebulized ultraviolet sensitive detergents into the artificial airway of a resuscitation dummy and performed CPR. The spread of the visualized aerosol was documented by a camera. In a further approach we applied nebulized detergents into the airways of human cadavers and detected the simulated spread on the same way. Among others we did recordings with undergoing compression-only-CPR, with a surgical mask or an oxygen mask on the patients face and with an inserted supraglottic airway device with and without a connected airway filter. RESULTS: Most aerosol-spread at the direction of the provider was visualized during compression-only-CPR. The use of a surgical mask and of an oxygen mask on the patient's face deflected the spread. Inserting a supraglottic airway device connected to an airway filter lead to a remarkable reduction of aerosol-spread. CONCLUSION: The early insertion of a supraglottic airway device connected to an airway filter before starting chest compression may be beneficial for staff protection during CPR.