A Critical Appraisal of the Effects of Anesthetics on Immune-system Modulation in Critically Ill Patients With COVID-19

Intestinal oxygen utilisation and cellular adaptation during intestinal ischaemia-reperfusion injury

The gastrointestinal tract can be deranged by ailments including sepsis, trauma and haemorrhage. Ischaemic injury provokes a common constellation of microscopic and macroscopic changes that, together with the paradoxical exacerbation of cellular dysfunction and death following restoration of blood flow, are collectively known as ischaemia-reperfusion injury (IRI). Although much of the gastrointestinal tract is normally hypoxemic, intestinal IRI results when there is inadequate oxygen availability due to poor supply (pathological hypoxia) or abnormal tissue oxygen use and metabolism (dysoxia). Intestinal oxygen uptake usually remains constant over a wide range of blood flows and pressures, with cellular function being substantively compromised when ischaemia leads to a >50% decline in intestinal oxygen consumption. Restoration of perfusion and oxygenation provokes additional injury, resulting in mucosal damage and disruption of intestinal barrier function. The primary cellular mechanism for sensing hypoxia and for activating a cascade of cellular responses to mitigate the injury is a family of heterodimer proteins called hypoxia-inducible factors (HIFs). The HIF system is connected to numerous biochemical and immunologic pathways induced by IRI and the concentration of those proteins increases during hypoxia and dysoxia. Activation of the HIF system leads to augmented transcription of specific genes in various types of affected cells, but may also augment apoptotic and inflammatory processes, thus aggravating gut injury. KEY POINTS: During intestinal ischaemia, mitochondrial oxygen uptake is reduced when cellular oxygen partial pressure decreases to below the threshold required to maintain normal oxidative metabolism. Upon reperfusion, intestinal hypoxia may persist because microcirculatory flow remains impaired and/or because available oxygen is consumed by enzymes, intestinal cells and neutrophils.

Strategies to Minimize Virus Transmission During Anesthesia Procedures in COVID-19 Patients

Anesthesiologists and the critical care team may be at increased risk of contracting severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2, COVID-19) due to airway manipulations and intubations performed during anesthesia administration and management of patient undergoing surgery. SARS-CoV-2 infections have been reported among healthcare workers. The virus is transmitted by close personal contact and aerosols. During intubation and other procedures involving the airway, the anesthesiologist is especially susceptible to aerosols. We performed a systematic analysis of the published reports on potential effects of COVID-19 during surgery on the anesthesiologist and critical care team. and identified potential immunomodulatory effects of general anesthetics in the presence of COVID-19 infection in patients. The article also provides critical discussion on the current medical management of COVID-19 and highlights the evidence-based key points for a safer practice during anesthesia administration and surgeries both in children and adults, including obstetric procedures and how it could affect pregnant women receiving anesthesia. With regional anesthesia, airway manipulation is not necessary, and healthcare workers and other patients are less likely to contract the same infection.

Perioperative Management of a Patient With Multiple Comorbidities Undergoing Lung Resection for Bronchopulmonary Carcinoid Complicated by SARS-CoV-2 Infection: A Case Report

We report a case of a high-risk patient with multiple comorbidities who underwent right median lobectomy and lymph node resection due to a carcinoid tumor. The patient's course was complicated by a hospital-acquired severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and a postoperative chest hematoma requiring urgent thoracotomy. Multidisciplinary and timely management resulted in a favorable patient outcome.

Effects of Etomidate on Postintubation Hypotension, Inflammatory Markers, and Mortality in Critically Ill Patients with COVID-19: An International, Multicenter, Retrospective Study

OBJECTIVE

To evaluate the association of etomidate with postintubation hypotension, inflammation, and mortality in critically ill patients with COVID-19.

DESIGN

International, multicenter, retrospective study.

PARTICIPANTS

Critically ill patients hospitalized specifically for COVID-19 from three major academic institutions in the US and Europe.

MAIN OUTCOME AND MEASURES

Patients were allocated into the etomidate (ET) group or another induction agent (OA) group. The primary outcome was postintubation hypotension. Secondary outcomes included postintubation inflammatory status, in-hospital mortality, and mortality at 30 days.

RESULTS

171 patients with a median age of 68 (IQR 58-73) years were included (ET, n  =  98; OA, n  =  73). Etomidate was associated with lower postintubation mean arterial pressure [74.33 (64-85) mm Hg versus 81.84 (69.75-94.25) mm Hg, p  =  0.005] compared to other agents. No statistically significant differences were generally observed in inflammatory markers between the two groups at 7- and 14-days after admission to the intensive care unit. In-hospital mortality [77 (79%) versus 41 (56%), p  =  0.003] and mortality at 30-days [78 (80%) versus 43 (59%), p  =  0.006] were higher in the ET group. In multivariate logistic regression analysis, only etomidate (p  =  0.009) and postintubation mean arterial pressure (p < 0.001) had a statistically significant effect on mortality, in contrast to stress-dose steroids (p  =  0.301), after adjusting for creatinine (p  =  0.695), blood urea nitrogen (p  =  0.153), age (p  =  0.055), oxygen saturation of hemoglobin (SpO2) (p  =  0.941), and fraction of inspired oxygen (FiO2) (p  =  0.712).

CONCLUSIONS

Administration of a single-bolus dose of etomidate in critically ill patients with COVID-19 is associated with lower postintubation mean arterial pressure and higher in-hospital and 30-day mortality compared to other induction agents.

The Role οf Ion Channels in the Development and Progression of Prostate Cancer

Ion channels have major regulatory functions in living cells. Apart from their role in ion transport, they are responsible for cellular electrogenesis and excitability, and may also regulate tissue homeostasis. Although cancer is not officially classified as a channelopathy, it has been increasingly recognized that ion channel aberrations play an important role in virtually all cancer types. Ion channels can exert pro-tumorigenic activities due to genetic or epigenetic alterations, or as a response to molecular signals, such as growth factors, hormones, etc. Increasing evidence suggests that ion channels and pumps play a critical role in the regulation of prostate cancer cell proliferation, apoptosis evasion, migration, epithelial-to-mesenchymal transition, and angiogenesis. There is also evidence suggesting that ion channels might play a role in treatment failure in patients with prostate cancer. Hence, they represent promising targets for diagnosis, staging, and treatment, and their effects may be of particular significance for specific patient populations, including those undergoing anesthesia and surgery. In this article, the role of major types of ion channels involved in the development and progression of prostate cancer are reviewed. Identifying the underlying molecular mechanisms of the pro-tumorigenic effects of ion channels may potentially inform the development of novel therapeutic strategies to counter this malignancy.

Remdesivir-induced Bradycardia is not Associated with Worse Outcome in Patients with COVID-19: A Retrospective Analysis

Background

COVID-19, is primarily a respiratory illness but is known to cause extrapulmonary manifestations, especially on the cardiovascular system. Bradycardia is commonly reported in COVID-19 patients despite no prior history of occurrence, and many studies have shown an association with increased mortality. Multiple case reports have been published showcasing remdesivir potentially causing bradycardia. Our aim was to investigate the incidence of bradycardia in patients receiving remdesivir and examine the association with disease severity and survival outcomes.

Methods

A retrospective study was performed including 160 COVID-19 patients receiving remdesivir for 5 days. Patients’ demographics, comorbidities, medication, vital signs, laboratory tests and outcome were recorded. Bradycardia was defined as a heart rate < 60 beats/min and severe bradycardia < 50 beats/min.

Results

One hundred eighteen (73.8%) patients experienced at least one episode of bradycardia during hospitalisation. Bradycardia was present in 12 (7.5%) patients before treatment with remdesivir. The rate of bradycardia increased up to the 6th day of hospitalisation (40.6%) and subsequently diminished and normalised within 5 days after the last remdesivir dose (5% at Day 10). Severe bradycardia was observed in 13 (7.5%) patients. No difference was observed in ICU admission between groups (bradycardia vs no bradycardia). When we stratified patients according to the outcome of hospitalisation, no significant difference was observed in the occurrence of bradycardia between groups (alive vs dead) [p = 0.853].

Conclusions

Treatment with remdesivir may be associated with new-onset bradycardia in hospitalised patients with COVID-19. However, bradycardia is transient and is not associated with ICU admission and mortality.

An atlas of dynamic peripheral blood mononuclear cell landscapes in human perioperative anaesthesia/surgery

BACKGROUND

The number of patients receiving anaesthesia is increasing, but the impact of general anaesthesia on the patient's immune system remains unclear. The aim of the present study is to investigate dynamics of systemic immune cell responses to anaesthesia during perioperative period at a single-cell solution.

METHODS

The peripheral blood mononuclear cells (PBMCs) and clinical phenomes were harvested and recorded 1 day before anaesthesia and operation, just after anaesthesia (0 h), and 24 and 48 h after anaesthesia. Single-cell sequencing of PBMCs was performed with 10× genomics. Subsequently, data analysis was performed with R packages: Seurat, clusterProfiler and CellPhoneDB.

RESULTS

We found that the cluster of CD56+ NK cells changed at 0 h and the cluster of monocytes increased at 24 and 48 h after anaesthesia. The characteristic genes of CD56+ NK cells were mainly enriched in the Jak-STAT signalling pathway and in cell adhesion molecules (24 h) and carbon metabolism (48 h). The communication between CD14+ monocytes and other cells decreased substantially 0 and 48 h after operation. The number of plasma cells enriched in protein export in men was substantially higher than that in women, although the total number in patients decreased 24 h after operation. CD14+ monocytes dominated that cell-cell communications appeared in females, while CD8+ NKT cells dominated that cell-cell communications appeared in male. The number of plasma cells increased substantially in patients with major surgical trauma, with enrichments of pentose phosphate pathway. The communications between plasma cells with other cells varied between surgical severities and anaesthetic forms. The intravenous anaesthesia caused major alterations of cell types, including CD14+ monocytes, plasmas cells and MAIT cells, as compared with inhalation anaesthesia.

CONCLUSION

We initially reported the roles of perioperative anaesthesia/surgery in temporal phenomes of circulating immune cells at a single-cell solution. Thus, the protection against immune cell changes would benefit the recovery from anaesthesia/surgery.

Sinus bradycardia is associated with poor outcome in critically ill patients with COVID-19 due to the B.1.1.7 Lineage

The progress of COVID-19 from moderate to severe may be precipitous, while the characteristics of the disease are heterogenous. The aim of this study was to describe the development of sinus bradycardia in critically ill patients with COVID-19 and its association with outcome in outbreak due to the SARS-CoV-2 B.1.1.7 Lineage. We leveraged the multi-center SuPAR in Adult Patients With COVID-19 (SPARCOL) study and identified patients who required admission to intensive care unit (ICU). Inclusion criteria were: (a) adult (≥18 years old) patients hospitalized primarily for COVID-19; (b) a confirmed SARS-CoV-2 infection diagnosed through reverse transcriptase polymerase chain reaction test of nasopharyngeal or oropharyngeal samples; and (c) at least one blood sample collected at admission and stored for suPAR, hs-CRP, and ferritin testing. All patients had continuous heart rate monitoring during hospitalization. In total, 81 patients were included. Of them, 17 (21 %) and 64 (79 %) were intubated and admitted to the ICU during the first and second wave, respectively. Two (12 %) and 62 (97 %) developed bradycardia before ICU admission, respectively (p < 0.001). Patients with bradycardia had increased suPAR (p < 0.001) and hs-CRP level (p < 0.001). Infusion of isoprenaline and/or noradrenaline was necessary to maintain an adequate rate and peripheral perfusion in all patients. Mortality was significantly higher in patients with bradycardia (p < 0.001). In conclusion, bradycardia was associated with poor outcome. As B.1.1.7 variant strain is spreading more rapidly in many countries, our findings help in the identification of patients who may require early admission to ICU.

Baseline Values and Kinetics of IL-6, Procalcitonin, and TNF-α in Landrace-Large White Swine Anesthetized with Propofol-Based Total Intravenous Anesthesia

The baseline levels of various inflammatory mediators and their changes during anesthesia in swine are not known. The aim of this animal study was to measure the baseline values and kinetics of interleukin-6, procalcitonin, and tumor necrosis factor-alpha in healthy Landrace-Large White swine anesthetized with propofol-based total intravenous anesthesia. We included 8 healthy male pigs with an average weight of 19 ± 2 kg (aged 10-15 weeks) that were subjected to propofol-based total intravenous anesthesia for 8 hours. Complete blood count, serum chemistry, and serum levels of interleukin-6, procalcitonin, and tumor necrosis factor-alpha were analyzed, and serum levels were quantified hourly. Blood was also collected for bacterial culturing. Baseline values of interleukin-6 and procalcitonin were 18 pg/ml and 21 ng/ml, respectively, while tumor necrosis factor-alpha was not detectable during collection of baseline samples. A statistically significant difference was observed in interleukin-6 levels between time points (p < 0.0001). Procalcitonin increased with time, but there were no significant differences between time points (p = 0.152). Tumor necrosis factor-alpha increased until the 3rd hour of propofol-based total intravenous anesthesia, while after the 4th hour, it gradually decreased, reaching its baseline undetectable values by the 7th hour (p < 0.001). Our results can serve as the basis for further translational research.