Respiratory support for adult patients with COVID-19

The COVID-19 pandemic is creating unique strains on the healthcare system. While only a small percentage of patients require mechanical ventilation and ICU care, the enormous size of the populations affected means that these critical resources may become limited. A number of non-invasive options exist to avert mechanical ventilation and ICU admission. This is a clinical review of these options and their applicability in adult COVID-19 patients. Summary recommendations include: (1) Avoid nebulized therapies. Consider metered dose inhaler alternatives. (2) Provide supplemental oxygen following usual treatment principles for hypoxic respiratory failure. Maintain awareness of the aerosol-generating potential of all devices, including nasal cannulas, simple face masks, and venturi masks. Use non-rebreather masks when possible. Be attentive to aerosol generation and the use of personal protective equipment. (3) High flow nasal oxygen is preferred for patients with higher oxygen support requirements. Non-invasive positive pressure ventilation may be associated with higher risk of nosocomial transmission. If used, measures special precautions should be used reduce aerosol formation. (4) Early intubation/mechanical ventilation may be prudent for patients deemed likely to progress to critical illness, multi-organ failure, or acute respiratory distress syndrome (ARDS).Copyright © 2020 The Authors. JACEP Open published by Wiley Periodicals LLC on behalf of the American College of Emergency Physicians.

Gas Pressure From the Endoscope: An Unexplored Contributor to Morbidity and Mortality?

Background It has been shown that the incidence of venous air embolism and venous carbon dioxide (CO2) embolism is high during endoscopic retrograde cholangiopancreatography (ERCP). We examined insufflating gas flow and maximum pressure produced by three types of commonly used endoscopes because we could not readily locate technical data for endoscope gas flow and maximum emitted pressure in the manufacturer's manuals. Methods We tested the Olympus GIF-Q180 used for esophagogastroduodenoscopy, the CF-Q180 used for colonoscopy, and the TJF-Q180 used for ERCP (Olympus America Inc., Center Valley, Pennsylvania). Under three different clinical gas insufflation scenarios, we measured in vitro maximum gas pressure transduced from a closed space created at the endoscope tip in a worst-case scenario analysis. Results We showed that it is readily possible to generate a pressure (>5-30 times normal central venous pressure) in the air space at the tip of all three endoscopes when insufflation is activated and the gas egress is limited. Conclusions These findings shed additional light on in vivo occurrences of gas embolism during gastrointestinal endoscopy. We postulate that in addition to using exclusively CO2 as the insufflating gas, the risk of gas embolism can be further diminished by regulating insufflating gas pressure at the tip of endoscopes.

Reducing aerosol dispersion by high flow therapy in COVID-19: High resolution computational fluid dynamics simulations of particle behavior during high velocity nasal insufflation with a simple surgical mask.

Objective: All respiratory care represents some risk of becoming an aerosol-generating procedure (AGP) during COVID-19 patient management. Personal protective equipment (PPE) and environmental control/engineering is advised. High velocity nasal insufflation (HVNI) and high flow nasal cannula (HFNC) deliver high flow oxygen (HFO) therapy, established as a competent means of supporting oxygenation for acute respiratory distress patients, including that precipitated by COVID-19. Although unlikely to present a disproportionate particle dispersal risk, AGP from HFO continues to be a concern. Previously, we published a preliminary model. Here, we present a subsequent highresolution simulation (higher complexity/reliability) to provide a more accurate and precise particle characterization on the effect of surgical masks on patients during HVNI, low-flow oxygen therapy (LFO2), and tidal breathing. Methods: This in silico modeling study of HVNI, LFO2, and tidal breathing presents ANSYS fluent computational fluid dynamics simulations that evaluate the effect of Type I surgical mask use over patient face on particle/droplet behavior. Results: This in silico modeling simulation study of HVNI (40 L min-1) with a simulated surgical mask suggests 88.8% capture of exhaled particulate mass in the mask, compared to 77.4% in LFO2 (6 L min-1) capture, with particle distribution escaping to the room (> 1 m from face) lower for HVNI+Mask versus LFO2+Mask (8.23% vs 17.2%). The overwhelming proportion of particulate escape was associated with mask-fit designed model gaps. Particle dispersion was associated with lower velocity. Conclusions: These simulations suggest employing a surgical mask over the HVNI interface may be useful in reduction of particulate mass distribution associated with AGPs.

Clinical outcomes of low-pressure pneumoperitoneum in minimally invasive urological surgery.

The adoption of minimally invasive laparoscopic techniques has revolutionised urological practice. This necessitates a pneumoperitoneum (PNP) and the impact the PNP pressure has on post-operative outcomes is uncertain. During the current COVID-19 era guidance has suggested the utilisation of lower PNP pressures to mitigate the risk of intra-operative viral transmission. Review the current literature regarding the impact of pneumoperitoneum pressure, within the field of urology, on post-operative outcomes. A search of the PubMed, Medline and EMBASE databases was undertaken to identify studies that met the inclusion criteria. The Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines were adhered to. Ten studies, that included both randomised controlled trials and retrospective case series reviews, were identified that met the inclusion criteria. The effect of PNP pressure on outcomes following prostatectomy, live donor nephrectomy, partial nephrectomy and a variety of benign upper tract procedures were discussed. Low pressure PNP appears safe when compared to high pressure PNP, potentially reducing post-operative pain and rates of ileus. When compared to general surgery, there is a lack of quality evidence investigating the impact of PNP pressures on outcomes within urology. Low pressure PNP appears non-inferior to high pressure PNP. More research is required to validate this finding, particularly post-cystectomy and nephrectomy.

Safety and efficiency of gasless laparoscopy: a systematic review protocol.

BACKGROUND: Gasless laparoscopy, developed in the early 1990s, was a means to minimize the clinical and financial challenges of pneumoperitoneum and general anaesthesia. It has been used in a variety of procedures such as in general surgery and gynecology procedures including diagnostic laparoscopy. There has been increasing evidence of the utility of gasless laparoscopy in resource limited settings where diagnostic imaging is not available. In addition, it may help save costs for hospitals. The aim of this study is to conduct a systematic review of the available evidence surrounding the safety and efficiency of gasless laparoscopy compared to conventional laparoscopy and open techniques and to analyze the benefits that gasless laparoscopy has for low resource setting hospitals. METHODS: This protocol is developed by following the Preferred Reporting Items for Systematic review and Meta-Analysis-Protocols (PRISMA-P). The PRISMA statement guidelines and flowchart will be used to conduct the study itself. MEDLINE (Ovid), Embase, Web of Science, Cochrane Central, and Global Index Medicus (WHO) will be searched and the National Institutes of Health Clinical Trials database. The articles that will be found will be pooled into Covidence article manager software where all the records will be screened for eligibility and duplicates removed. A data extraction spreadsheet will be developed based on variables of interest set a priori. Reviewers will then screen all included studies based on the eligibility criteria. The GRADE tool will be used to assess the quality of the studies and the risk of bias in all the studies will be assessed using the Cochrane Risk assessment tool. The RoB II tool will assed the risk of bias in randomized control studies and the ROBINS I will be used for the non-randomized studies. DISCUSSION: This study will be a comprehensive review on all published articles found using this search strategy on the safety and efficiency of the use of gasless laparoscopy. The systematic review outcomes will include safety and efficiency of gasless laparoscopy compared to the use of conventional laparoscopy or laparotomy. TRIAL REGISTRATION: The study has been registered in PROSPERO under registration number: CRD42017078338.

Compassionate Use of Rectal Ozone (O3) in Severe COVID-19 Pneumonia: a Case-Control Study.

Objectives: To evaluate effect of rectal ozone in severe COVID-19 pneumonia and to compare it to standard of care (SOC). Material and Methods: In a case-control study, 14 patients with severe bilateral COVID-19 pneumonia (positive RT-PCR), treated with SOC and rectal ozone, were evaluated before-and-after treatment and compared with SOC (14 patients) in a 10-day follow-up period. Ozone protocol consisted of 8 sessions (1 session/day) of intra-rectal ozone (150 mL volume, 35 µg/mL concentration [5.25mg total dose]). The SOC protocol included O2 supply, antivirals (Remdesivir), corticosteroids (Dexamethasone/Metilprednisolone), monoclonal antibodies (Anakinra/Tocilizumab), antibiotics (Azytromicine), and anticoagulants (Enoxaparine). Primary outcome variables were the following: (a) clinical (O2 saturation and O2 supply); (b) biochemical (lymphocyte count, fibrinogen, D-dimer, urea, ferritin, LDH, IL-6, and CRP); (c) radiological Taylor's scale. Secondary outcome variables were the following: (a) hospitalization length of stay, (b) mortality rate. Results: At baseline, ozone/SOC groups were not different on age, comorbidities, O2 saturation, and O2 supply. Patients in the ozone group improved O2 saturation and decrease O2 supply. SOC maintained O2 saturation and required more O2 supply. Lymphocyte count improved only in the ozone group and with statistical difference (p<0.05). Biomarkers of inflammation (fibrinogen, D-dimer, urea, LDH, CRP, and IL-6) decreased in both groups, but only significantly in favor of the ozone group (p<0.05). Ferritin showed a significant decrease in the ozone group but an increase on the SOC group. Radiological pneumonitis decreased on both groups but the decrease was only significant in the ozone group (p<0.0001). Mortality and length of stay, although not significant, were inferior in the ozone group. Conclusion: Compassionate use of rectal ozone improved O2 saturation, reduced O2 supply, decreased inflammation biomarkers, and improved Taylor's radiological scale significantly when compared to the SOC group. Mortality and length of stay were inferior in the ozone group, but this difference was not significant.

Transnasal humidified rapid-insufflation ventilatory exchange ('THRIVE') in the coronavirus disease 2019 pandemic.

BACKGROUND: Since the start of the coronavirus disease 2019 pandemic, transnasal humidified rapid-insufflation ventilatory exchange ('THRIVE') has been classified as a high-risk aerosol-generating procedure and is strongly discouraged, despite a lack of conclusive evidence on its safety. METHODS: This study aimed to investigate the safety of transnasal humidified rapid-insufflation ventilatory exchange usage and its impact on staff members. A prospective study was conducted on all transnasal humidified rapid-insufflation ventilatory exchange cases performed in our unit between March and July 2020. RESULTS: During the study period, 18 patients with a variety of airway pathologies were successfully managed with transnasal humidified rapid-insufflation ventilatory exchange. For each case, 7-10 staff members were present. Appropriate personal protective equipment protocols were strictly implemented and adhered to. None of the staff involved reported symptoms or tested positive for coronavirus disease 2019, up to at least a month following their exposure to transnasal humidified rapid-insufflation ventilatory exchange. CONCLUSION: With strictly correct personal protective equipment use, transnasal humidified rapid-insufflation ventilatory exchange can be safely employed for carefully selected patients in the current pandemic, without jeopardising the health and safety of the ENT and anaesthetic workforce.

Stop the leak!: Mitigating potential exposure of aerosolized COVID-19 during laparoscopic surgery.

BACKGROUND: Viral particles have been shown to aerosolize into insufflated gas during laparoscopic surgery. In the operating room, this potentially exposes personnel to aerosolized viruses as well as carcinogens. In light of circumstances surrounding COVID-19 and a concern for the safety of healthcare professionals, our study seeks to quantify the volumes of gas leaked from dynamic interactions between laparoscopic instruments and the trocar port to better understand potential exposure to surgically aerosolized particles. METHODS: A custom setup was constructed to simulate an insufflated laparoscopic surgical cavity. Two surgical instrument use scenarios were examined to observe and quantify opportunities for insufflation gas leakage. Both scenarios considered multiple configurations of instrument and trocar port sizes/dimensions: (1) the full insertion and full removal of a laparoscopic instrument from the port and (2) the movement of the scope within the port, recognized as "dynamic interaction", which occurs nearly 100% of the time over the course of any procedure. RESULTS: For a 5 mm instrument in a 5 mm trocar, the average volume of gas leaked during dynamic interaction and full insertion/removal scenarios were 43.67 and 25.97 mL of gas, respectively. Volume of gas leaked for a 5 mm instrument in a 12 mm port averaged 41.32 mL and 29.47 for dynamic interaction vs. instrument insertion and removal. Similar patterns were shown with a 10 mm instrument in 12 mm port, with 55.68 mL for the dynamic interaction and 58.59 for the instrument insertion/removal. CONCLUSIONS: Dynamic interactions and insertion/removal events between laparoscopic instruments and ports appear to contribute to consistent leakage of insufflated gas into the OR. Any measures possible taken to reduce OR gas leakage should be considered in light of the current COVID-19 pandemic. Minimizing laparoscope and instrument removal and replacement would be one strategy to mitigate gas leakage during laparoscopic surgery.

Can surgery follow the dictates of the pandemic "keep your distance"? Requirements with COVID-19 for hygiene, resources and the team.

Since the beginning of the pandemic, there have been restrictions in the daily care of surgical patients - both elective and emergency. Readying supply capacities and establishing isolation areas and areas for suspected cases in the clinics have led to keeping beds free for treating (suspected) COVID-19 cases. It was therefore necessary to temporarily postpone elective surgery. Now, elective care can be gradually resumed with the second phase of the pandemic in Germany. However, it remains the order of the day to adapt pre-, intra- and post-operative procedures to the new COVID-19 conditions while maintaining specialized hygiene measures. This concerns the correct procedure for the use of personal protective materials as well as process adjustment for parallel treatment of positive and negative patients in the central OR, and handling of aerosols in the operating theater, operating room, and surgical site under consideration of staff and patient protection. Although dealing with surgical smoke in the operating theater has long been criticized, COVID-19 is forcing a renaissance in this area. Finally, the choice of surgical method, whether open surgery or minimally invasive procedures, is critical in determining how many colleagues are exposed to the risk of infection from COVID-19 patients, sometimes for hours. Here, robot-assisted surgery can comply with the pandemic's requirement to "keep your distance" in a unique way, since the surgeon can operate at virtually any distance from the surgical site, at least with regard to aerosol formation and exposure.

A 55-year-old COVID-19-positive man managed with self-regulation of high-flow oxygen by high-velocity nasal insufflation therapy.

Management of critically ill coronavirus disease 2019 (COVID-19) patients remains both risky and technically challenging. A 55-year-old male COVID-19-positive patient with obstructive sleep apnoea (OSA), diabetes, and obesity presented with cough and shortness of breath, escalating to requiring high-flow oxygen therapy by high-velocity nasal insufflation. The patient's flow rate and oxygen fraction remained labile throughout much of the hospitalization. This lability required frequent clinician interactions and use of personal protective equipment. The patient was alert and oriented and was instructed on the operation of the high-flow system, specifically the adjustment of both flow rate and oxygen percentage. The patient was instructed to modify oxygen to maintain an SpO2 (peripheral capillary oxygen saturation) target range, and flow rate to address dyspnoea as well as reduction of flow as tolerated when other staff entered the room. The patient was successfully self-regulated for 10 days and was discharged on 2 L/min nasal cannula on day 14 of his illness.