21 results found
Ritchie A, Kadwani O, Saleh D, et al., 2022, Clinical and Survival differences during separate COVID-19 surges: investigating the impact of the Sars-CoV-2 alpha variant in critical care patients, PLoS One, Vol: 17, ISSN: 1932-6203
A number of studies have highlighted physiological data from the first surge in critically unwell Covid-19 patients but there is a paucity of data describing emerging variants of SARS-CoV-2, such as B.1.1.7. We compared ventilatory parameters, biochemical and physiological data and mortality between the first and second COVID-19 surges in the United Kingdom, where distinct variants of SARS-CoV-2 were the dominant stain. We performed a retrospective cohort study investigating critically unwell patients admitted with COVID-19 across three tertiary regional ICUs in London, UK. Of 1782 adult ICU patients screened, 330 intubated and ventilated patients diagnosed with COVID-19 were included. In the second wave where B.1.1.7 variant was the dominant strain, patients were had increased severity of ARDS whilst compliance was greater (p<0.05) and d-dimer lower. The 28-day mortality was not statistically significant (1st wave: 42.2% vs 2nd wave: 39.8%). However, when adjusted for key covariates, the hazard ratio for 28-day mortality in those patients with B.1.1.7 was 3.79 (CI 1.04–13.8; p=0.043) compared to the original strain. During the second surge in the UK, where theCOVID-19 variant B.1.1.7 was most prevalent, significantly more patients presented to critical care with severe ARDS. Furthermore, mortality risk was significantly greater in our ICU population during the second wave of the pandemic in those patients with B.1.1.7. As ICUs are experiencing further waves (particularly by the delta (B.1.617.2) variant), we highlight the urgent need for prospective studies describing immunological and pathophysiological differences across novel emerging variants.
Watson N, Brown E, Ritchie AI, et al., 2022, Recommended reading from the Imperial College, London fellows, American Journal of Respiratory and Critical Care Medicine, Vol: 205, Pages: 1470-1473, ISSN: 1073-449X
Supplementary oxygen is widely used in critically unwell patients; however, the optimal regime of oxygen therapy is a topic of ongoing debate. Although hypoxemia is dangerous, in vitro evidence suggests that exposing alveolar epithelium to supranormal oxygen concentration causes free radical formation (1). Clinically, hyperoxia (defined as a PaO2 value greater than the normal range for a patient’s age when breathing air ) can lead to absorption atelectasis, central nervous system toxicity, reduced cardiac output, and systemic vasoconstriction, all of which could compound critical illness. To mitigate this, the safety of conservative oxygen therapy has been investigated in critically ill patients, and several studies have demonstrated noninferiority of conservative oxygen therapy (3–5), whereas a meta-analysis found that this strategy conferred a mortality benefit (6). The following recent articles (Table 1) assess the effect of conservative versus liberal oxygen treatment on patient outcomes in the critical care environment. The importance of this literature is emphasized by ongoing challenges associated with an expanding number of critically ill patients and increased demand on healthcare resources, in particular oxygen reserves.
Soni S, O'Dea K, Abe E, et al., 2022, Microvesicle-mediated communication within the alveolar space: mechanisms of uptake by epithelial cells and alveolar macrophages, Frontiers in Immunology, Vol: 13, ISSN: 1664-3224
Intra-alveolar microvesicles (MVs) are important mediators of inter-cellular communication within the alveolar space, and are key components in the pathophysiology of lung inflammation such as acute respiratory distress syndrome (ARDS). Despite the abundance of data detailing the pro-inflammatory effects of MVs, it remains unclear how MVs interact or signal with target cells in the alveolus. Using both in vivo and in vitro alveolar models, we analyzed the dynamics of MV uptake by resident alveolar cells: alveolar macrophages and epithelial cells. Under resting conditions, the overwhelming majority of MVs were taken up by alveolar macrophages. However, following lipopolysaccharide (LPS)-mediated inflammation, epithelial cells internalized significantly more MVs (p<0.01) whilst alveolar macrophage internalization was significantly reduced (p<0.01). We found that alveolar macrophages adopted a pro-inflammatory phenotype after internalizing MVs under resting conditions, but reduction of MV uptake following LPS pre-treatment was associated with loss of inflammatory phenotype. Instead, MVs induced significant epithelial cell inflammation following LPS pre-treatment, when MV internalization was most significant. Using pharmacological inhibitors, we interrogated the mechanisms of MV internalization to identify which endocytic pathways and cell surface receptors are involved. We demonstrated that epithelial cells are exclusively dependent on the clathrin and caveolin dependent endocytotic pathway, whereas alveolar macrophage uptake may involve a significant phagocytic component. Furthermore, alveolar macrophages predominantly engulf MVs via scavenger receptors whilst, epithelial cells internalize MVs via a phosphatidylserine/integrin receptor mediated pathway (specifically alpha V beta III), which can be inhibited with phosphatidylserine-binding protein (i.e. annexin V). In summary, we have undertaken a comprehensive evaluation of MV internalization within the alveolar
Huq F, manners E, O'Callaghan D, et al., 2022, Patient outcomes following transfer between intensive care units during the COVID-19 pandemic, Anaesthesia, Vol: 77, Pages: 398-404, ISSN: 0003-2409
Transferring critically ill patients between intensive care units is often required in the UK, particularly during the COVID-19 pandemic. However, there is a paucity of data examining clinical outcomes following transfer of patients with COVID-19 and whether this strategy affects their acute physiology or outcome. We investigated all transfers critically ill patients with COVID-19 between three different hospital intensive care units, between March 2020 and March 2021. We focused on inter-hospital intensive care unit transfers, i.e. those patients transferred between intensive care units from different hospitals and compared this cohort with intra-hospital intensive care unit transfers, i.e. patients moved between different intensive care units within the same hospital. A total of 507 transfers were assessed, of which 137 met the inclusion criteria. Forty-five patients underwent inter-hospital transfers compared with 92 intra-hospital transfers. There was no significant change in median compliance 6 hours pre-transfer, immediately post-transfer and 24 hours post-transfer in patients who underwent either intra-hospital or inter-hospital transfers. For inter-hospital transfers, there was an initial drop in median PaO2/FiO2 ratio: from median (IQR [range]) 25.1 (17.8–33.7 [12.1–78.0]) kPa 6 hours pre-transfer to 19.5 (14.6–28.9 [9.8–52.0]) kPa immediately post-transfer (p<0.05). However, this had resolved at 24 hours post-transfer: 25.4 (16.2–32.9 [9.4–51.9]) kPa. For intra-hospital transfers, there was no significant change in PaO2/FiO2 ratio. We also found no meaningful difference in pH; PaCO2;, base excess; bicarbonate; or norepinephrine requirements. Our data demonstrate that patients with COVID-19 undergoing mechanical ventilation of the lungs may have short-term physiological deterioration when transferred between nearby hospitals but this resolves within 24 hours. This finding is relevant to the UK critical care strategy in
Koh MW, Baldi RF, Soni S, et al., 2021, Secreted extracellular cyclophilin a is a novel mediator of ventilator induced lung injury., American Journal of Respiratory and Critical Care Medicine, Vol: 204, Pages: 421-430, ISSN: 1073-449X
RATIONALE: Mechanical ventilation is a mainstay of intensive care but contributes to the mortality of patients through ventilator induced lung injury. Extracellular Cyclophilin A is an emerging inflammatory mediator and metalloproteinase inducer, and the gene responsible for its expression has recently been linked to COVID-19 infection. OBJECTIVES: Here we explore the involvement of extracellular Cyclophilin A in the pathophysiology of ventilator-induced lung injury. METHODS: Mice were ventilated with low or high tidal volume for up to 3 hours, with or without blockade of extracellular Cyclophilin A signalling, and lung injury and inflammation were evaluated. Human primary alveolar epithelial cells were exposed to in vitro stretch to explore the cellular source of extracellular Cyclophilin A, and Cyclophilin A levels were measured in bronchoalveolar lavage fluid from acute respiratory distress syndrome patients, to evaluate clinical relevance. MEASUREMENTS AND MAIN RESULTS: High tidal volume ventilation in mice provoked a rapid increase in soluble Cyclophilin A levels in the alveolar space, but not plasma. In vivo ventilation and in vitro stretch experiments indicated alveolar epithelium as the likely major source. In vivo blockade of extracellular Cyclophilin A signalling substantially attenuated physiological dysfunction, macrophage activation and matrix metalloproteinases. Finally, we found that patients with acute respiratory distress syndrome showed markedly elevated levels of extracellular Cyclophilin A within bronchoalveolar lavage. CONCLUSIONS: Cyclophilin A is upregulated within the lungs of injuriously ventilated mice (and critically ill patients), where it plays a significant role in lung injury. Extracellular Cyclophilin A represents an exciting novel target for pharmacological intervention.
Stephens J, Wong J, Broomhead R, et al., 2021, Raised serum amylase in patients with COVID-19 may not be associated with pancreatitis, British Journal of Surgery, Vol: 108, Pages: 152-153, ISSN: 0007-1323
Chia G, Barrett H, Patel P, et al., 2021, One hundred eighteen days on a ventilator: a COVID-19 success story against all odds, BMJ Case Reports, Vol: 14, Pages: 1-4, ISSN: 1757-790X
Emerging data suggest that patients with certain comorbidities requiring intensive care unit (ICU) admission for COVID-19 have a poor prognosis. This report describes a case of a patient with multiple comorbidities who contracted COVID-19 pneumonitis but was successfully weaned off invasive mechanical ventilation after 118 days, despite his admission being complicated by recurrent septic episodes and requirement for advanced cardiovascular support and renal replacement therapy. Of note, our patient received three courses of steroids in total during his ICU stay,and current literature strongly supports the use of steroids in critically unwell patients with COVID-19. To the best of our knowledge, this is the longest reported ventilated time and intensive care/hospital stay for a surviving patient with COVID-19 and highlights the importance of allowing sufficient time for clinical interventions to take effect, even when the prognosis appears bleak.
Chaggar RS, Shah SV, Berry M, et al., 2021, The Video Classification of Intubation (VCI) score: a new description tool for tracheal intubation using videolaryngoscopy, European Journal of Anaesthesiology, Vol: 38, Pages: 324-326, ISSN: 0265-0215
Soni S, Garner J, O'Dea K, et al., 2021, Intra-alveolar neutrophil-derived microvesicles are associated with disease severity in COPD, American Journal of Physiology: Lung Cellular and Molecular Physiology, Vol: 320, Pages: L73-L83, ISSN: 1040-0605
Despite advances in the pathophysiology of Chronic Obstructive Pulmonary Disease (COPD), there is a distinct lack of biochemical markers to aid clinical management. Microvesicles (MVs) have been implicated in the pathophysiology of inflammatory diseases including COPD but their association to COPD disease severity remains unknown. We analysed different MV populations in plasma and bronchoalveolar lavage fluid (BALF) taken from sixty-two patients with mild to very severe COPD (51% male; mean age: 65.9 years). These patients underwent comprehensive clinical evaluation (symptom scores, lung function, exercise testing) and the capacity of MVs to be clinical markers of disease severity was assessed. We successfully identified various MV subtype populations within BALF (leukocyte, PMN (polymorphonuclear leukocyte i.e. neutrophil), monocyte, epithelial and platelet MVs) and plasma (leukocyte, PMN, monocyte and endothelial MVs), and compared each MV population to disease severity. BALF neutrophil MVs were the only population to significantly correlate with the clinical evaluation scores including FEV1, mMRC dyspnoea score, 6-minute walk test, hyperinflation and gas transfer. BALF neutrophil MVs, but not neutrophil cell numbers, also strongly correlated with BODE index. We have undertaken, for the first time, a comprehensive evaluation of MV profiles within BALF/plasma of COPD patients. We demonstrate that BALF levels of neutrophil-derived MVs are unique in correlating with a number of key functional and clinically-relevant disease severity indices. Our results show the potential of BALF neutrophil MVs for a COPD biomarker that tightly links a key pathophysiological mechanism of COPD (intra-alveolar neutrophil activation) with clinical severity/outcome.
Gasparini M, Khan S, Patel JM, et al., 2020, Renal impairment and its impact on clinical outcomes in patients who are critically ill with COVID-19: a multicentre observational study, ANAESTHESIA, Vol: 76, Pages: 320-326, ISSN: 0003-2409
Soni S, Shah S, Chaggar R, et al., 2020, Surgical cancellation rates due to peri‐operative hypertension: implementation of multidisciplinary guidelines across primary and secondary care, Anaesthesia, Vol: 75, Pages: 1314-1320, ISSN: 0003-2409
Patients with uncontrolled hypertension are at increased risk of complications during general anaesthesia but the number of patients whose surgery is delayed or cancelled due to hypertension remains unknown. Prospective, regional multicentre service evaluations were performed on consecutive patients undergoing elective surgery before and after the publication of new guidelines from the Association of Anaesthetists and the British Hypertensive Society. The aim was to quantify the number of operations cancelled due to hypertension alone and to assess impact of the guidelines on cancellation rates. In October 2013 (before the publication of the guidelines), 1.37% (95%CI 0.69–2.11%) of patients listed for elective surgery were cancelled solely due to raised blood pressure. This reduced significantly to 0.54% (95%CI 0.20–0.92%, p < 0.001) in 2018. There was a significant reduction in inappropriate cancellations for stage 1 or 2 hypertension from 2013 to 2018 (72 vs. 14, respectively, p < 0.001) in keeping with the recommendations in the guidelines. Furthermore, the number of patients being referred back to primary care for the management of hypertension reduced from 2013 to 2018 (85 vs. 30, respectively, p < 0.001). Our data suggest achievement of three major outcomes: reduced surgical cancellations due to hypertension alone; improved detection of significant hypertension before elective surgery; and reduced referral back to primary care from hospital for hypertension management. To the best of our knowledge, this is the first time the successful implementation of guidelines from the Association of Anaesthetists has been assessed on such a broad scale. Our data indicate that these guidelines have been effectively implemented in both primary and secondary care, which is likely to have made a positive psychosocial, physical and economic impact on patients and the NHS.
Stephens JR, Stümpfle R, Patel P, et al., 2020, Analysis of critical care severity of illness scoring systems in patients with coronavirus disease 2019: a retrospective analysis of three U.K. ICUs., Critical Care Medicine, Vol: 49, Pages: e105-e107, ISSN: 0090-3493
O'Dea K, Tan YY, Shah S, et al., 2020, Monocytes mediate homing of circulating microvesicles to the pulmonaryvasculature during low-grade systemic inflammation, Journal of Extracellular Vesicles, Vol: 9, Pages: 1-16, ISSN: 2001-3078
Microvesicles (MVs), a plasma membrane-derived subclass of extracellular vesicles, are produced and released into the circulation during systemic inflammation, yet little is known of cell/tissue-specific uptake of MVs under these conditions. We hypothesized that monocytes contribute to uptake of circulating MVs and that their increased margination to the pulmonary circulation and functional priming during systemic inflammation produces substantive changes to the systemic MV homing profile. Cellular uptake of i.v.-injected, fluorescently labelled MVs (J774.1 macrophage-derived) in vivo was quantified by flow cytometry in vascular cell populations of the lungs, liver and spleen of C57BL6 mice. Under normal conditions, both Ly6Chigh and Ly6Clow monocytes contributed to MV uptake but liver Kupffer cells were the dominant target cell population. Following induction of sub-clinical endotoxemia with low-dose i.v. LPS, MV uptake by lung-marginated Ly6Chigh monocytes increased markedly, both at the individual cell level (~2.5-fold) and through substantive expansion of their numbers (~8-fold), whereas uptake by splenic macrophages was unchanged and uptake by Kupffer cells actually decreased (~50%). Further analysis of MV uptake within the pulmonary vasculature using a combined model approach of in vivo macrophage depletion, ex vivo isolated perfused lungs and in vitro lung perfusate cell-based assays, indicated that Ly6Chigh monocytes possess a high MV uptake capacity (equivalent to Kupffer cells), that is enhanced directly by endotoxemia and ablated in the presence of phosphatidylserine (PS)-enriched liposomes and β3 integrin receptor blocking peptide. Accordingly, i.v.-injected PS-enriched liposomes underwent a redistribution of cellular uptake during endotoxemia similar to MVs, with enhanced uptake by Ly6Chigh monocytes and reduced uptake by Kupffer cells. These findings indicate that monocytes, particularly lung-marginated Ly6Chigh subset monocytes, become a dominant
Oakley C, Koh M, Baldi R, et al., 2019, Ventilation following established ARDS: a preclinical model framework to improve predictive power, Thorax, Vol: 74, Pages: 1120-1129, ISSN: 1468-3296
Background Despite advances in understanding the pathophysiology of acute respiratory distress syndrome, effective pharmacological interventions have proven elusive. We believe this is a consequence of existing preclinical models being designed primarily to explore biological pathways, rather than predict treatment effects. Here, we describe a mouse model in which both therapeutic intervention and ventilation were superimposed onto existing injury and explored the impact of β-agonist treatment, which is effective in simple models but not clinically.Methods Mice had lung injury induced by intranasal lipopolysaccharide (LPS), which peaked at 48 hours post-LPS based on clinically relevant parameters including hypoxaemia and impaired mechanics. At this peak of injury, mice were treated intratracheally with either terbutaline or tumour necrosis factor (TNF) receptor 1-targeting domain antibody, and ventilated with moderate tidal volume (20 mL/kg) to induce secondary ventilator-induced lung injury (VILI).Results Ventilation of LPS-injured mice at 20 mL/kg exacerbated injury compared with low tidal volume (8 mL/kg). While terbutaline attenuated VILI within non-LPS-treated animals, it was ineffective to reduce VILI in pre-injured mice, mimicking its lack of clinical efficacy. In contrast, anti-TNF receptor 1 antibody attenuated secondary VILI within pre-injured lungs, indicating that the model was treatable.Conclusions We propose adoption of a practical framework like that described here to reduce the number of ultimately ineffective drugs reaching clinical trials. Novel targets should be evaluated alongside interventions which have been previously tested clinically, using models that recapitulate the (lack of) clinical efficacy. Within such a framework, outperforming a failed pharmacologic should be a prerequisite for drugs entering trials.
Soni S, Tirlapur N, O'Dea KP, et al., 2019, Microvesicles as new therapeutic targets for the treatment of the acute respiratory distress syndrome (ARDS), EXPERT OPINION ON THERAPEUTIC TARGETS, Vol: 23, Pages: 931-941, ISSN: 1472-8222
Soni S, O'Dea K, Tan YY, et al., 2019, ATP redirects cytokine trafficking and promotes novel membrane TNF signalling via microvesicles, FASEB Journal, ISSN: 0892-6638
Cellular stress or injury induces release of endogenous danger signals such as ATP, which plays a central role in activating immune cells. ATP is essential for the release of nonclassically secreted cytokines such as IL-1β but, paradoxically, has been reported to inhibit the release of classically secreted cytokines such as TNF. Here, we reveal that ATP does switch off soluble TNF (17 kDa) release from LPS-treated macrophages, but rather than inhibiting the entire TNF secretion, ATP packages membrane TNF (26 kDa) within microvesicles (MVs). Secretion of membrane TNF within MVs bypasses the conventional endoplasmic reticulum– and Golgi transport–dependent pathway and is mediated by acid sphingomyelinase. These membrane TNF–carrying MVs are biologically more potent than soluble TNF in vivo, producing significant lung inflammation in mice. Thus, ATP critically alters TNF trafficking and secretion from macrophages, inducing novel unconventional membrane TNF signaling via MVs without direct cell-to-cell contact. These data have crucial implications for this key cytokine, particularly when therapeutically targeting TNF in acute inflammatory diseases.—Soni, S., O’Dea, K. P., Tan, Y. Y., Cho, K., Abe, E., Romano, R., Cui, J., Ma, D., Sarathchandra, P., Wilson, M. R., Takata, M. ATP redirects cytokine trafficking and promotes novel membrane TNF signaling via microvesicles.
Davies R, O'Dea KP, Soni S, et al., 2017, P362: Vasopressin alone and with noradrenaline attenuates TNF-α production in an in-vitro model of monocyte priming and deactivation, 37th International Symposium on Intensive Care and Emergency Medicine, Publisher: BioMed Central, ISSN: 1364-8535
Soni S, Wilson MR, O'Dea KP, et al., 2016, Alveolar macrophage-derived microvesicles mediate acute lung injury, Thorax, Vol: 71, Pages: 1020-1029, ISSN: 1468-3296
Background Microvesicles (MVs) are important mediators of intercellular communication, packaging a variety of molecular cargo. They have been implicated in the pathophysiology of various inflammatory diseases; yet, their role in acute lung injury (ALI) remains unknown.Objectives We aimed to identify the biological activity and functional role of intra-alveolar MVs in ALI.Methods Lipopolysaccharide (LPS) was instilled intratracheally into C57BL/6 mice, and MV populations in bronchoalveolar lavage fluid (BALF) were evaluated. BALF MVs were isolated 1 hour post LPS, assessed for cytokine content and incubated with murine lung epithelial (MLE-12) cells. In separate experiments, primary alveolar macrophage-derived MVs were incubated with MLE-12 cells or instilled intratracheally into mice.Results Alveolar macrophages and epithelial cells rapidly released MVs into the alveoli following LPS. At 1 hour, the dominant population was alveolar macrophage-derived, and these MVs carried substantive amounts of tumour necrosis factor (TNF) but minimal amounts of IL-1β/IL-6. Incubation of these mixed MVs with MLE-12 cells induced epithelial intercellular adhesion molecule-1 (ICAM-1) expression and keratinocyte-derived cytokine release compared with MVs from untreated mice (p<0.001). MVs released in vitro from LPS-primed alveolar macrophages caused similar increases in MLE-12 ICAM-1 expression, which was mediated by TNF. When instilled intratracheally into mice, these MVs induced increases in BALF neutrophils, protein and epithelial cell ICAM-1 expression (p<0.05).Conclusions We demonstrate, for the first time, the sequential production of MVs from different intra-alveolar precursor cells during the early phase of ALI. Our findings suggest that alveolar macrophage-derived MVs, which carry biologically active TNF, may play an important role in initiating ALI.
Soni S, Johannsson H, 2013, Does regional anaesthesia in trauma patients lead to delayed recognition of compartment syndrome?, British Journal of Hospital Medicine, Vol: 74, Pages: 358-358, ISSN: 1750-8460
Soni S, Moss P, Jaiganesh T, 2011, Idiopathic adult intussusception, International Journal of Emergency Medicine, Vol: 4
Soni S, Gandhi S, 2009, Flecainide overdose causing a Brugada-type pattern on electrocardiogram in a previously well patient, The American Journal of Emergency Medicine, Vol: 27, Pages: 375.e1-375.e3, ISSN: 0735-6757
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