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Abstract
BACKGROUND In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation. METHODS This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation <92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg-800 mg (depending on weight) given intravenously. A second dose could be given 12-24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). FINDINGS Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76-0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12-1·33; p<0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77-0·92; p<0·0001). INTERPRETATION In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids. FUNDING UK Research and Innovation (Medical Research Council) and National Institute of Health Research.
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Clinical Trial, Phase II |
4 |
948 |
2
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Tobin MJ, Laghi F, Jubran A. Why COVID-19 Silent Hypoxemia Is Baffling to Physicians. Am J Respir Crit Care Med 2020; 202:356-360. [PMID: 32539537 PMCID: PMC7397783 DOI: 10.1164/rccm.202006-2157cp] [Citation(s) in RCA: 374] [Impact Index Per Article: 74.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 06/15/2020] [Indexed: 02/07/2023] Open
Abstract
Patients with coronavirus disease (COVID-19) are described as exhibiting oxygen levels incompatible with life without dyspnea. The pairing-dubbed happy hypoxia but more precisely termed silent hypoxemia-is especially bewildering to physicians and is considered as defying basic biology. This combination has attracted extensive coverage in media but has not been discussed in medical journals. It is possible that coronavirus has an idiosyncratic action on receptors involved in chemosensitivity to oxygen, but well-established pathophysiological mechanisms can account for most, if not all, cases of silent hypoxemia. These mechanisms include the way dyspnea and the respiratory centers respond to low levels of oxygen, the way the prevailing carbon dioxide tension (PaCO2) blunts the brain's response to hypoxia, effects of disease and age on control of breathing, inaccuracy of pulse oximetry at low oxygen saturations, and temperature-induced shifts in the oxygen dissociation curve. Without knowledge of these mechanisms, physicians caring for patients with hypoxemia free of dyspnea are operating in the dark, placing vulnerable patients with COVID-19 at considerable risk. In conclusion, features of COVID-19 that physicians find baffling become less strange when viewed in light of long-established principles of respiratory physiology; an understanding of these mechanisms will enhance patient care if the much-anticipated second wave emerges.
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Case Reports |
5 |
374 |
3
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Editorial |
5 |
200 |
4
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News |
5 |
150 |
5
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Hashemian SMR, Aliannejad R, Zarrabi M, Soleimani M, Vosough M, Hosseini SE, Hossieni H, Keshel SH, Naderpour Z, Hajizadeh-Saffar E, Shajareh E, Jamaati H, Soufi-Zomorrod M, Khavandgar N, Alemi H, Karimi A, Pak N, Rouzbahani NH, Nouri M, Sorouri M, Kashani L, Madani H, Aghdami N, Vasei M, Baharvand H. Mesenchymal stem cells derived from perinatal tissues for treatment of critically ill COVID-19-induced ARDS patients: a case series. Stem Cell Res Ther 2021; 12:91. [PMID: 33514427 PMCID: PMC7844804 DOI: 10.1186/s13287-021-02165-4] [Citation(s) in RCA: 144] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 01/12/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Acute respiratory distress syndrome (ARDS) is a fatal complication of coronavirus disease 2019 (COVID-19). There are a few reports of allogeneic human mesenchymal stem cells (MSCs) as a potential treatment for ARDS. In this phase 1 clinical trial, we present the safety, feasibility, and tolerability of the multiple infusions of high dose MSCs, which originated from the placenta and umbilical cord, in critically ill COVID-19-induced ARDS patients. METHODS A total of 11 patients diagnosed with COVID-19-induced ARDS who were admitted to the intensive care units (ICUs) of two hospitals enrolled in this study. The patients were critically ill with severe hypoxemia and required mechanical ventilation. The patients received three intravenous infusions (200 × 106 cells) every other day for a total of 600 × 106 human umbilical cord MSCs (UC-MSCs; 6 cases) or placental MSCs (PL-MSCs; 5 cases). FINDINGS There were eight men and three women who were 42 to 66 years of age. Of these, six (55%) patients had comorbidities of diabetes, hypertension, chronic lymphocytic leukemia (CLL), and cardiomyopathy (CMP). There were no serious adverse events reported 24-48 h after the cell infusions. We observed reduced dyspnea and increased SpO2 within 48-96 h after the first infusion in seven patients. Of these seven patients, five were discharged from the ICU within 2-7 days (average: 4 days), one patient who had signs of acute renal and hepatic failure was discharged from the ICU on day 18, and the last patient suddenly developed cardiac arrest on day 7 of the cell infusion. Significant reductions in serum levels of tumor necrosis factor-alpha (TNF-α; P < 0.01), IL-8 (P < 0.05), and C-reactive protein (CRP) (P < 0.01) were seen in all six survivors. IL-6 levels decreased in five (P = 0.06) patients and interferon gamma (IFN-γ) levels decreased in four (P = 0.14) patients. Four patients who had signs of multi-organ failure or sepsis died in 5-19 days (average: 10 days) after the first MSC infusion. A low percentage of lymphocytes (< 10%) and leukocytosis were associated with poor outcome (P = 0.02). All six survivors were well with no complaints of dyspnea on day 60 post-infusion. Radiological parameters of the lung computed tomography (CT) scans showed remarkable signs of recovery. INTERPRETATION We suggest that multiple infusions of high dose allogeneic prenatal MSCs are safe and can rapidly improve respiratory distress and reduce inflammatory biomarkers in some critically ill COVID-19-induced ARDS cases. Patients that develop sepsis or multi-organ failure may not be good candidates for stem cell therapy. Large randomized multicenter clinical trials are needed to discern the exact therapeutic potentials of MSC in COVID-19-induced ARDS.
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Clinical Trial, Phase I |
4 |
144 |
6
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Asadi-Pooya AA. Seizures associated with coronavirus infections. Seizure 2020; 79:49-52. [PMID: 32416567 PMCID: PMC7212943 DOI: 10.1016/j.seizure.2020.05.005] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/03/2020] [Accepted: 05/05/2020] [Indexed: 12/22/2022] Open
Abstract
Neurotropic and neuroinvasive capabilities of coronaviruses have been described in humans. Neurological problems found in patients with coronavirus infection include: febrile seizures, convulsions, loss of consciousness, encephalomyelitis, and encephalitis. Coronavirus disease (COVID-19) is caused by SARS-CoV2. In severe cases, patients may develop severe pneumonia, acute respiratory distress syndrome, and acute cardiac injury. While seizures and status epilepticus have not been widely reported in the past five months since the onset of COVID-19 pandemic, patients with COVID-19 may have hypoxia, multiorgan failure, and severe metabolic and electrolyte disarrangements; hence, it is plausible to expect clinical or subclinical acute symptomatic seizures to happen in these patients. One should be prepared to treat seizures appropriately, if they happen in a patient who is already in a critical medical condition and suffers from organ failure.
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Review |
5 |
110 |
7
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Hallin GW, Simpson SQ, Crowell RE, James DS, Koster FT, Mertz GJ, Levy H. Cardiopulmonary manifestations of hantavirus pulmonary syndrome. Crit Care Med 1996; 24:252-8. [PMID: 8605797 DOI: 10.1097/00003246-199602000-00012] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To describe the clinical characteristics of a group of patients infected with the newly recognized hantavirus in the Southwestern United States. DESIGN Case series. SETTING Tertiary referral center. PATIENTS All patients with confirmed hantavirus infection admitted to the University of New Mexico Hospital between May 1, 1993 and January 1, 1994. INTERVENTIONS Records of patients with hantavirus infection were reviewed to collect all pertinent clinical data. MEASUREMENTS AND MAIN RESULTS Pulmonary disease in these patients was characterized by hypoxemia covering a wide range of severity. The cause of hypoxemia was an increased permeability (noncardiac) pulmonary edema which could be differentiated from hydrostatic (cardiac) pulmonary edema by its association with low pulmonary artery occlusion pressures and increased protein content of edema fluid. Hemodynamic measurements in severe cases showed a shock state characterized by a low cardiac index (range 1.6 to 3.0 L/min/min2), a low stroke volume index (range 10.5 to 29 mL/m2), and high systemic vascular resistance index (range 1,653 to 2,997 dyne.sec/cm5.m2). Progression to death was associated with worsening cardiac dysfunction unresponsive to treatment and causing oxygen debt and lactic acidosis. CONCLUSIONS The two major life-threatening pathophysiologic changes in Hantavirus Pulmonary Syndrome are increased permeability pulmonary edema, and an atypical form of septic shock caused by myocardial depression and hypovolemia.
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29 |
110 |
8
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Rogero MM, Leão MDC, Santana TM, Pimentel MVDMB, Carlini GCG, da Silveira TFF, Gonçalves RC, Castro IA. Potential benefits and risks of omega-3 fatty acids supplementation to patients with COVID-19. Free Radic Biol Med 2020; 156:190-199. [PMID: 32653511 PMCID: PMC7350587 DOI: 10.1016/j.freeradbiomed.2020.07.005] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/26/2020] [Accepted: 07/05/2020] [Indexed: 12/13/2022]
Abstract
Studies have shown that infection, excessive coagulation, cytokine storm, leukopenia, lymphopenia, hypoxemia and oxidative stress have also been observed in critically ill Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) patients in addition to the onset symptoms. There are still no approved drugs or vaccines. Dietary supplements could possibly improve the patient's recovery. Omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), present an anti-inflammatory effect that could ameliorate some patients need for intensive care unit (ICU) admission. EPA and DHA replace arachidonic acid (ARA) in the phospholipid membranes. When oxidized by enzymes, EPA and DHA contribute to the synthesis of less inflammatory eicosanoids and specialized pro-resolving lipid mediators (SPMs), such as resolvins, maresins and protectins. This reduces inflammation. In contrast, some studies have reported that EPA and DHA can make cell membranes more susceptible to non-enzymatic oxidation mediated by reactive oxygen species, leading to the formation of potentially toxic oxidation products and increasing the oxidative stress. Although the inflammatory resolution improved by EPA and DHA could contribute to the recovery of patients infected with SARS-CoV-2, Omega-3 fatty acids supplementation cannot be recommended before randomized and controlled trials are carried out.
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Review |
5 |
104 |
9
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Griffin DO, Jensen A, Khan M, Chin J, Chin K, Saad J, Parnell R, Awwad C, Patel D. Pulmonary Embolism and Increased Levels of d-Dimer in Patients with Coronavirus Disease. Emerg Infect Dis 2020; 26:1941-1943. [PMID: 32348233 PMCID: PMC7392455 DOI: 10.3201/eid2608.201477] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We report 3 patients with coronavirus disease who had a decline in respiratory status during their hospital course that responded well to intravenous steroids and interleukin-6 receptor antagonist therapy. These patients later showed development of persistent hypoxia with increased levels of d-dimer levels and were given a diagnosis of pulmonary embolisms.
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Journal Article |
5 |
73 |
10
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Ottestad W, Seim M, Mæhlen JO. COVID-19 with silent hypoxemia. TIDSSKRIFT FOR DEN NORSKE LEGEFORENING 2020; 140:20-0299. [PMID: 32378842 DOI: 10.4045/tidsskr.20.0299] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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Journal Article |
5 |
64 |
11
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Wu Y, Wang T, Guo C, Zhang D, Ge X, Huang Z, Zhou X, Li Y, Peng Q, Li J. Plasminogen improves lung lesions and hypoxemia in patients with COVID-19. QJM 2020; 113:539-545. [PMID: 32275753 PMCID: PMC7184376 DOI: 10.1093/qjmed/hcaa121] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/01/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Lungs from patients with coronavirus disease 2019 (COVID-19) have shown typical signs of acute respiratory distress syndrome (ARDS), formation of hyaline membrane mainly composed of fibrin and 'ground-glass' opacity. Previously, we showed plasminogen itself is a key regulator in fibrin degradation, wound healing and infection. AIM We aimed to investigate whether plasminogen can improve lung lesions and hypoxemia of COVID-19. DESIGN Thirteen clinically moderate, severe or critical COVID-19 patients were treated with atomization inhalation of freeze-dried plasminogen. METHODS Levels of their lung lesions, oxygen saturation and heart rates were compared before and after treatment by computed tomography scanning images and patient monitor. RESULTS After plasminogen inhalation, conditions of lung lesions in five clinically moderate patients have quickly improved, shown as the decreased range and density of 'ground glass' opacity. Improvements of oxygen saturation were observed in six clinically severe patients. In the two patients with critical conditions, the oxygen levels have significantly increased from 79-82% to 91% just about 1 h after the first inhalation. In 8 of 13 patients, the heart rates had slowed down. For the five clinically moderate patients, the difference is even statistically significant. Furthermore, a general relief of chest tightness was observed. CONCLUSION Whereas it is reported that plasminogen is dramatically increased in adults with ARDS, this study suggests that additional plasminogen may be effective and efficient in treating lung lesions and hypoxemia during COVID-19 infections. Although further studies are needed, this study highlights a possible hope of efficiently combating this rapid epidemic emergency.
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Multicenter Study |
5 |
59 |
12
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Chen AY, Kleiboeker S, Qiu J. Productive parvovirus B19 infection of primary human erythroid progenitor cells at hypoxia is regulated by STAT5A and MEK signaling but not HIFα. PLoS Pathog 2011; 7:e1002088. [PMID: 21698228 PMCID: PMC3116823 DOI: 10.1371/journal.ppat.1002088] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 04/12/2011] [Indexed: 01/30/2023] Open
Abstract
Human parvovirus B19 (B19V) causes a variety of human diseases. Disease outcomes of bone marrow failure in patients with high turnover of red blood cells and immunocompromised conditions, and fetal hydrops in pregnant women are resulted from the targeting and destruction of specifically erythroid progenitors of the human bone marrow by B19V. Although the ex vivo expanded erythroid progenitor cells recently used for studies of B19V infection are highly permissive, they produce progeny viruses inefficiently. In the current study, we aimed to identify the mechanism that underlies productive B19V infection of erythroid progenitor cells cultured in a physiologically relevant environment. Here, we demonstrate an effective reverse genetic system of B19V, and that B19V infection of ex vivo expanded erythroid progenitor cells at 1% O(2) (hypoxia) produces progeny viruses continuously and efficiently at a level of approximately 10 times higher than that seen in the context of normoxia. With regard to mechanism, we show that hypoxia promotes replication of the B19V genome within the nucleus, and that this is independent of the canonical PHD/HIFα pathway, but dependent on STAT5A and MEK/ERK signaling. We further show that simultaneous upregulation of STAT5A signaling and down-regulation of MEK/ERK signaling boosts the level of B19V infection in erythroid progenitor cells under normoxia to that in cells under hypoxia. We conclude that B19V infection of ex vivo expanded erythroid progenitor cells at hypoxia closely mimics native infection of erythroid progenitors in human bone marrow, maintains erythroid progenitors at a stage conducive to efficient production of progeny viruses, and is regulated by the STAT5A and MEK/ERK pathways.
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Research Support, N.I.H., Extramural |
14 |
56 |
13
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Coppadoro A, Benini A, Fruscio R, Verga L, Mazzola P, Bellelli G, Carbone M, Mulinacci G, Soria A, Noè B, Beck E, Di Sciacca R, Ippolito D, Citerio G, Valsecchi MG, Biondi A, Pesci A, Bonfanti P, Gaudesi D, Bellani G, Foti G. Helmet CPAP to treat hypoxic pneumonia outside the ICU: an observational study during the COVID-19 outbreak. Crit Care 2021; 25:80. [PMID: 33627169 PMCID: PMC7903369 DOI: 10.1186/s13054-021-03502-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 02/10/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Respiratory failure due to COVID-19 pneumonia is associated with high mortality and may overwhelm health care systems, due to the surge of patients requiring advanced respiratory support. Shortage of intensive care unit (ICU) beds required many patients to be treated outside the ICU despite severe gas exchange impairment. Helmet is an effective interface to provide continuous positive airway pressure (CPAP) noninvasively. We report data about the usefulness of helmet CPAP during pandemic, either as treatment, a bridge to intubation or a rescue therapy for patients with care limitations (DNI). METHODS In this observational study we collected data regarding patients failing standard oxygen therapy (i.e., non-rebreathing mask) due to COVID-19 pneumonia treated with a free flow helmet CPAP system. Patients' data were recorded before, at initiation of CPAP treatment and once a day, thereafter. CPAP failure was defined as a composite outcome of intubation or death. RESULTS A total of 306 patients were included; 42% were deemed as DNI. Helmet CPAP treatment was successful in 69% of the full treatment and 28% of the DNI patients (P < 0.001). With helmet CPAP, PaO2/FiO2 ratio doubled from about 100 to 200 mmHg (P < 0.001); respiratory rate decreased from 28 [22-32] to 24 [20-29] breaths per minute, P < 0.001). C-reactive protein, time to oxygen mask failure, age, PaO2/FiO2 during CPAP, number of comorbidities were independently associated with CPAP failure. Helmet CPAP was maintained for 6 [3-9] days, almost continuously during the first two days. None of the full treatment patients died before intubation in the wards. CONCLUSIONS Helmet CPAP treatment is feasible for several days outside the ICU, despite persistent impairment in gas exchange. It was used, without escalating to intubation, in the majority of full treatment patients after standard oxygen therapy failed. DNI patients could benefit from helmet CPAP as rescue therapy to improve survival. TRIAL REGISTRATION NCT04424992.
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Observational Study |
4 |
54 |
14
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Navas-Blanco JR, Dudaryk R. Management of Respiratory Distress Syndrome due to COVID-19 infection. BMC Anesthesiol 2020; 20:177. [PMID: 32689937 PMCID: PMC7369540 DOI: 10.1186/s12871-020-01095-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/13/2020] [Indexed: 01/08/2023] Open
Abstract
The management of Acute Respiratory Distress Syndrome (ARDS) secondary to the novel Coronavirus Disease 2019 (COVID-19) proves to be challenging and controversial. Multiple studies have suggested the likelihood of an atypical pathophysiology to explain the spectrum of pulmonary and systemic manifestations caused by the virus. The principal paradox of COVID-19 pneumonia is the presence of severe hypoxemia with preserved pulmonary mechanics. Data derived from the experience of multiple centers around the world have demonstrated that initial clinical efforts should be focused into avoid intubation and mechanical ventilation in hypoxemic COVID-19 patients. On the other hand, COVID-19 patients progressing or presenting into frank ARDS with typical decreased pulmonary compliance, represents another clinical enigma to many clinicians, since routine therapeutic interventions for ARDS are still a subject of debate.
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Review |
5 |
52 |
15
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Nouri-Vaskeh M, Sharifi A, Khalili N, Zand R, Sharifi A. Dyspneic and non-dyspneic (silent) hypoxemia in COVID-19: Possible neurological mechanism. Clin Neurol Neurosurg 2020; 198:106217. [PMID: 32947193 PMCID: PMC7480672 DOI: 10.1016/j.clineuro.2020.106217] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/03/2020] [Accepted: 09/04/2020] [Indexed: 01/04/2023]
Abstract
SARS-CoV-2 mainly invades respiratory epithelial cells by adhesion to angiotensin-converting enzyme 2 (ACE-2) and thus, infected patients may develop mild to severe inflammatory responses and acute lung injury. Afferent impulses that result from the stimulation of pulmonary mechano-chemoreceptors, peripheral and central chemoreceptors by inflammatory cytokines are conducted to the brainstem. Integration and processing of these input signals occur within the central nervous system, especially in the limbic system and sensorimotor cortex, and importantly feedback regulation exists between O2, CO2, and blood pH. Despite the intensity of hypoxemia in COVID-19, the intensity of dyspnea sensation is inappropriate to the degree of hypoxemia in some patients (silent hypoxemia). We hypothesize that SARS-CoV-2 may cause neuronal damage in the corticolimbic network and subsequently alter the perception of dyspnea and the control of respiration. SARS-CoV-2 neuronal infection may change the secretion of numerous endogenous neuropeptides or neurotransmitters that distribute through large areas of the nervous system to produce cellular and perceptual effects. SARS-CoV-2 mainly enter to CNS via direct (neuronal and hematologic route) and indirect route. We theorize that SARS-CoV-2 infection-induced neuronal cell damage and may change the balance of endogenous neuropeptides or neurotransmitters that distribute through large areas of the nervous system to produce cellular and perceptual effects. Thus, SARS-CoV-2-associated neuronal damage may influence the control of respiration by interacting in neuromodulation. This would open up possible lines of study for the progress in the central mechanism of COVID-19-induced hypoxia. Future research is desirable to confirm or disprove such a hypothesis.
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review-article |
5 |
51 |
16
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Bailey DM, Davies B, Romer L, Castell L, Newsholme E, Gandy G. Implications of moderate altitude training for sea-level endurance in elite distance runners. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1998; 78:360-8. [PMID: 9754977 DOI: 10.1007/s004210050432] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Elite distance runners participated in one of two studies designed to investigate the effects of moderate altitude training (inspiratory partial pressure of oxygen approximately 115-125 mmHg) on submaximal, maximal and supramaximal exercise performance following return to sea-level. Study 1 (New Mexico, USA) involved 14 subjects who were assigned to a 4-week altitude training camp (1500-2000 m) whilst 9 performance-matched subjects continued with an identical training programme at sea-level (CON). Ten EXP subjects who trained at 1640 m and 19 CON subjects also participated in study 2 (Krugersdorp, South Africa). Selected metabolic and cardiorespiratory parameters were determined with the subjects at rest and during exercise 21 days prior to (PRE) and 10 and 20 days following their return to sea-level (POST). Whole blood lactate decreased by 23% (P < 0.05 vs PRE) during submaximal exercise in the EXP group only after 20 days at sea-level (study 1). However, the lactate threshold and other measures of running economy remained unchanged. Similarly, supramaximal performance during a standardised track session did not change. Study 2 demonstrated that hypoxia per se did not alter performance. In contrast, in the EXP group supramaximal running velocity decreased by 2% (P < 0.05) after 20 days at sea-level. Both studies were characterised by a 50% increase in the frequency of upper respiratory and gastrointestinal tract infections during the altitude sojourns, and two male subjects were diagnosed with infectious mononucleosis following their return to sea-level (study 1). Group mean plasma glutamine concentrations at rest decreased by 19% or 143 (74) microM (P < 0.001) after 3 weeks at altitude, which may have been implicated in the increased incidence of infectious illness.
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27 |
48 |
17
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Bénet T, Picot VS, Awasthi S, Pandey N, Bavdekar A, Kawade A, Robinson A, Rakoto-Andrianarivelo M, Sylla M, Diallo S, Russomando G, Basualdo W, Komurian-Pradel F, Endtz H, Vanhems P, Paranhos-Baccalà G, for the GABRIEL Network. Severity of Pneumonia in Under 5-Year-Old Children from Developing Countries: A Multicenter, Prospective, Observational Study. Am J Trop Med Hyg 2017; 97:68-76. [PMID: 28719310 PMCID: PMC5508893 DOI: 10.4269/ajtmh.16-0733] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 01/30/2017] [Indexed: 01/11/2023] Open
Abstract
Pneumonia is the leading cause of death in children. The objectives were to evaluate the microbiological agents linked with hypoxemia in hospitalized children with pneumonia from developing countries, to identify predictors of hypoxemia, and to characterize factors associated with in-hospital mortality. A multicenter, observational study was conducted in five hospitals, from India (Lucknow, Vadu), Madagascar (Antananarivo), Mali (Bamako), and Paraguay (San Lorenzo). Children aged 2-60 months with radiologically confirmed pneumonia were enrolled prospectively. Respiratory and whole blood specimens were collected, identifying viruses and bacteria by real-time multiplex polymerase chain reaction (PCR). Microbiological agents linked with hypoxemia at admission (oxygen saturation < 90%) were analyzed by multivariate logistic regression, and factors associated with 14-day in-hospital mortality were assessed by bivariate Cox regression. Overall, 405 pneumonia cases (3,338 hospitalization days) were analyzed; 13 patients died within 14 days of hospitalization. Hypoxemia prevalence was 17.3%. Detection of human metapneumovirus (hMPV) and respiratory syncytial virus (RSV) in respiratory samples was independently associated with increased risk of hypoxemia (adjusted odds ratio [aOR] = 2.4, 95% confidence interval [95% CI] = 1.0-5.8 and aOR = 2.5, 95% CI = 1.1-5.3, respectively). Lower chest indrawing and cyanosis were predictive of hypoxemia (positive likelihood ratios = 2.3 and 2.4, respectively). Predictors of death were Streptococcus pneumoniae detection by blood PCR (crude hazard ratio [cHR] = 4.6, 95% CI = 1.5-14.0), procalcitonin ≥ 50 ng/mL (cHR = 22.4, 95% CI = 7.3-68.5) and hypoxemia (cHR = 4.8, 95% CI = 1.6-14.4). These findings were consistent on bivariate analysis. hMPV and RSV in respiratory samples were linked with hypoxemia, and S. pneumoniae in blood was associated with increased risk of death among hospitalized children with pneumonia in developing countries.
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Comparative Study |
8 |
44 |
18
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Friedman J, Calderón-Villarreal A, Bojorquez I, Vera Hernández C, Schriger DL, Tovar Hirashima E. Excess Out-of-Hospital Mortality and Declining Oxygen Saturation: The Sentinel Role of Emergency Medical Services Data in the COVID-19 Crisis in Tijuana, Mexico. Ann Emerg Med 2020; 76:413-426. [PMID: 33012377 PMCID: PMC7377712 DOI: 10.1016/j.annemergmed.2020.07.035] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/17/2020] [Accepted: 07/21/2020] [Indexed: 01/29/2023]
Abstract
STUDY OBJECTIVE Emergency medical services (EMS) may serve as a key source of real-time data about the evolving health of coronavirus disease 2019 (COVID-19)-affected populations, especially in low- and middle-income countries with less rapid and reliable vital statistics registration systems. Although official COVID-19 statistics in Mexico report almost exclusively inhospital mortality events, excess out-of-hospital mortality has been identified in other countries, including 1 EMS study in Italy that showed a 58% increase. Additionally, EMS and hospital reports from several countries have suggested that silent hypoxemia-low Spo2 in the absence of dyspnea-is associated with COVID-19. It is unclear, however, how these phenomena can be generalized to low- and middle-income countries. We assess how EMS data can be used in a sentinel capacity in Tijuana, a city on the Mexico-United States border with earlier exposure to COVID-19 than many low- and middle-income country settings. METHODS In this observational study, we calculated numbers of weekly out-of-hospital deaths and respiratory cases handled by EMS in Tijuana, and estimated the difference between peak epidemic rates and expected trends based on data from 2014 to 2019. Results were compared with official COVID-19 statistics, stratified by neighborhood socioeconomic status, and examined for changing demographic or clinical features, including mean Spo2. RESULTS An estimated 194.7 excess out-of-hospital deaths (95% confidence interval 135.5 to 253.9 deaths) occurred during the peak window (April 14 to May 11), representing an increase of 145% (95% CI 70% to 338%) compared with expected levels. During the same window, only 5 COVID-19-related out-of-hospital deaths were reported in official statistics. This corresponded with an increase in respiratory cases of 236.5% (95% CI 100.7% to 940.0%) and a decrease in mean Spo2 to 77.7% from 90.2% at baseline. The highest out-of-hospital death rates were observed in low-socioeconomic-status areas, although respiratory cases were more concentrated in high-socioeconomic-status areas. CONCLUSION EMS systems may play an important sentinel role in monitoring excess out-of-hospital mortality and other trends during the COVID-19 crisis in low- and middle-income countries. Using EMS data, we observed increases in out-of-hospital deaths in Tijuana that were nearly 3-fold greater than increases reported in EMS data in Italy. Increased testing in out-of-hospital settings may be required to determine whether excess mortality is being driven by COVID-19 infection, health system saturation, or patient avoidance of health care. We also found evidence of worsening rates of hypoxemia among respiratory patients treated by EMS, suggesting a possible increase in silent hypoxemia, which should be met with increased detection and clinical management efforts. Finally, we observed social disparities in out-of-hospital death that warrant monitoring and amelioration.
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Observational Study |
5 |
43 |
19
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Ranieri VM, Tonetti T, Navalesi P, Nava S, Antonelli M, Pesenti A, Grasselli G, Grieco DL, Menga LS, Pisani L, Boscolo A, Sella N, Pasin L, Mega C, Pizzilli G, Dell’Olio A, Dongilli R, Rucci P, Slutsky AS. High-Flow Nasal Oxygen for Severe Hypoxemia: Oxygenation Response and Outcome in Patients with COVID-19. Am J Respir Crit Care Med 2022; 205:431-439. [PMID: 34861135 PMCID: PMC8886947 DOI: 10.1164/rccm.202109-2163oc] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/03/2021] [Indexed: 11/16/2022] Open
Abstract
Rationale: The "Berlin definition" of acute respiratory distress syndrome (ARDS) does not allow inclusion of patients receiving high-flow nasal oxygen (HFNO). However, several articles have proposed that criteria for defining ARDS should be broadened to allow inclusion of patients receiving HFNO. Objectives: To compare the proportion of patients fulfilling ARDS criteria during HFNO and soon after intubation, and 28-day mortality between patients treated exclusively with HFNO and patients transitioned from HFNO to invasive mechanical ventilation (IMV). Methods: From previously published studies, we analyzed patients with coronavirus disease (COVID-19) who had PaO2/FiO2 of ⩽300 while treated with ⩾40 L/min HFNO, or noninvasive ventilation (NIV) with positive end-expiratory pressure of ⩾5 cm H2O (comparator). In patients transitioned from HFNO/NIV to invasive mechanical ventilation (IMV), we compared ARDS severity during HFNO/NIV and soon after IMV. We compared 28-day mortality in patients treated exclusively with HFNO/NIV versus patients transitioned to IMV. Measurements and Main Results: We analyzed 184 and 131 patients receiving HFNO or NIV, respectively. A total of 112 HFNO and 69 NIV patients transitioned to IMV. Of those, 104 (92.9%) patients on HFNO and 66 (95.7%) on NIV continued to have PaO2/FiO2 ⩽300 under IMV. Twenty-eight-day mortality in patients who remained on HFNO was 4.2% (3/72), whereas in patients transitioned from HFNO to IMV, it was 28.6% (32/112) (P < 0.001). Twenty-eight-day mortality in patients who remained on NIV was 1.6% (1/62), whereas in patients who transitioned from NIV to IMV, it was 44.9% (31/69) (P < 0.001). Overall mortality was 19.0% (35/184) and 24.4% (32/131) for HFNO and NIV, respectively (P = 0.2479). Conclusions: Broadening the ARDS definition to include patients on HFNO with PaO2/FiO2 ⩽300 may identify patients at earlier stages of disease but with lower mortality.
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Comparative Study |
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42 |
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Habashi NM, Camporota L, Gatto LA, Nieman G. Functional pathophysiology of SARS-CoV-2-induced acute lung injury and clinical implications. J Appl Physiol (1985) 2021; 130:877-891. [PMID: 33444117 PMCID: PMC7984238 DOI: 10.1152/japplphysiol.00742.2020] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 02/08/2023] Open
Abstract
The worldwide pandemic caused by the SARS-CoV-2 virus has resulted in over 84,407,000 cases, with over 1,800,000 deaths when this paper was submitted, with comorbidities such as gender, race, age, body mass, diabetes, and hypertension greatly exacerbating mortality. This review will analyze the rapidly increasing knowledge of COVID-19-induced lung pathophysiology. Although controversial, the acute respiratory distress syndrome (ARDS) associated with COVID-19 (CARDS) seems to present as two distinct phenotypes: type L and type H. The "L" refers to low elastance, ventilation/perfusion ratio, lung weight, and recruitability, and the "H" refers to high pulmonary elastance, shunt, edema, and recruitability. However, the LUNG-SAFE (Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure) and ESICM (European Society of Intensive Care Medicine) Trials Groups have shown that ∼13% of the mechanically ventilated non-COVID-19 ARDS patients have the type-L phenotype. Other studies have shown that CARDS and ARDS respiratory mechanics overlap and that standard ventilation strategies apply to these patients. The mechanisms causing alterations in pulmonary perfusion could be caused by some combination of 1) renin-angiotensin system dysregulation, 2) thrombosis caused by loss of endothelial barrier, 3) endothelial dysfunction causing loss of hypoxic pulmonary vasoconstriction perfusion control, and 4) hyperperfusion of collapsed lung tissue that has been directly measured and supported by a computational model. A flowchart has been constructed highlighting the need for personalized and adaptive ventilation strategies, such as the time-controlled adaptive ventilation method, to set and adjust the airway pressure release ventilation mode, which recently was shown to be effective at improving oxygenation and reducing inspiratory fraction of oxygen, vasopressors, and sedation in patients with COVID-19.
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Research Support, N.I.H., Extramural |
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42 |
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Suhren JT, Meinardus A, Hussein K, Schaumann N. Meta-analysis on COVID-19-pregnancy-related placental pathologies shows no specific pattern. Placenta 2022; 117:72-77. [PMID: 34773743 PMCID: PMC8525005 DOI: 10.1016/j.placenta.2021.10.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/23/2021] [Accepted: 10/18/2021] [Indexed: 01/02/2023]
Abstract
Coronavirus disease 2019 (COVID-19) pneumonia rarely occurs in pregnant women. Case reports indicate that fibrin and lymphohistiocytic lesions in placentas may be typical. However, a meta-analysis to clarify whether there is a COVID-19-associated pattern of placental lesions has not yet been conducted. Systematic literature search with meta-analysis of publications on 10 or more cases of pregnancy with SARS-CoV-2 infection and placenta examination (30 publications from 2019 to 2021; 1452 placenta cases) was performed. The meta-analysis did not reveal any COVID-19-specific placenta changes. The incidence of both vascular and inflammatory lesions was mainly comparable to that of non-COVID-19 pregnancies. Transplacental viral transmission is very rare and there are no typical placental changes. The most important prognostic factor seems to be maternal-fetal hypoxia in the context of pneumonia.
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Meta-Analysis |
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35 |
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Moriyama Y, Hamada H, Okada M, Tsuchiya N, Maru H, Shirato Y, Maeda Y, Hirose Y, Yoshida M, Omura Y, Honda T, Muto A, Hayashi K, Terai M. Distinctive clinical features of human bocavirus in children younger than 2 years. Eur J Pediatr 2010; 169:1087-92. [PMID: 20383526 PMCID: PMC2908446 DOI: 10.1007/s00431-010-1183-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Accepted: 02/25/2010] [Indexed: 01/28/2023]
Abstract
BACKGROUND AND OBJECTIVE Clinical characteristics of human bocavirus (HBoV) infection have been studied worldwide, but their importance of those characteristics remains unknown. We investigated distinctive clinical features of HBoV-positive children with lower respiratory tract infection (LRTI). METHODS AND RESULTS During April 2007-July 2009, for 402 hospitalized children younger than 2 years with LRTI, we prospectively examined virus genomes in nasopharyngeal swabs for HBoV, respiratory syncytial virus (RSV), rhinovirus, metapneumovirus, parainfluenzavirus, and adenovirus. The HBoV genomes were identified in 34 patients (8.5%). Clinical and laboratory data of HBoV-positive and other virus/bacteria-negative patients (n = 18) were analyzed and compared with data of RSV-single positive patients (n = 99). The seasonal distribution of HBoV exhibits a concentration of cases during March-September, with most RSV cases occurring during winter in Japan. The minimum age of HBoV-positive patients was 5 months, although 44 patients (44%) with RSV were younger than 6 months. The main clinical features were respiratory distress and hypoxia. Hypoxia advances within 3 days after onset. The mean oxygen saturation on arrival was 92.8%, which was significantly lower than that in patients with RSV (p < 0.001). White blood cell counts were similar among groups. However, the percentage of neutrophils in white blood cells were significantly higher in HBoV-positive patients (62 vs. 45%, p < 0.001). Their prognoses were good. Their hospital stays were 6.6 days. CONCLUSIONS HBoV-single positive patients show several clinical characteristics, such as seasonality, age, hypoxia, and neutrophilia, which differ from those with RSV infection.
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Comparative Study |
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34 |
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Shen BH, Bauzon M, Hermiston TW. The effect of hypoxia on the uptake, replication and lytic potential of group B adenovirus type 3 (Ad3) and type 11p (Ad11p). Gene Ther 2006; 13:986-90. [PMID: 16525485 DOI: 10.1038/sj.gt.3302736] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Replicating, tumor selective viruses are being tested as potential treatments for human cancers. Hypoxia is a pathophysiological cancer condition that alters the lytic potential of the replication-competent adenovirus serotype 5 (Ad5) virus by a mechanism independent of receptor levels or internalization rates. We extend these initial studies to examine the potential effects of hypoxia on the group B adenoviruses (Ads), adenovirus type 3 (Ad3) (group B1) and adenovirus type 11p (Ad11p) (group B2). Receptor expression (CD46) is not altered by hypoxia. However, the lytic potential is compromised in a cell-dependent fashion. Consequently, our study suggests that group B replicating Ad-based treatments, like the group C Ad-5-based viruses, will need to be modified in order to effectively treat hypoxic components of human tumors.
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Abstract
Viral respiratory infections are the most likely trigger for sudden infant death syndrome (SIDS). SIDS cases commonly have evidence of respiratory tract inflammation, a preceding history of symptoms of minor illness and occur in winter peaks coinciding with respiratory viral epidemics. Respiratory infections are a common cause for infants presenting with sudden events, involving apnoea and hypoxaemia and there are physiological mechanisms by which infants may develop sudden and severe, potentially life-threatening hypoxaemia. The rate of SIDS has fallen in the last 15 years. This is probably more to do with the reasons for the fall in deaths from respiratory causes rather than changes in sleeping position. Further falls in SIDS death rates may occur with reductions in cigarette smoking, encouragement of breastfeeding and minimising the potential for young infants to acquire respiratory infections. Early identification and recognition of life-threatening features of infections may further minimise the risks of sudden death.
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Review |
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31 |
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Chandra A, Chakraborty U, Pal J, Karmakar P. Silent hypoxia: a frequently overlooked clinical entity in patients with COVID-19. BMJ Case Rep 2020; 13:e237207. [PMID: 32900744 PMCID: PMC7478026 DOI: 10.1136/bcr-2020-237207] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2020] [Indexed: 01/05/2023] Open
Abstract
COVID-19 caused by SARS-CoV-2 may present with a wide spectrum of symptoms ranging from mild upper respiratory tract infection like illness to severe pneumonia and death. Patients may have severe hypoxaemia without proportional features of respiratory distress, also known as 'silent' or 'apathetic' hypoxia. We present a case of a 56-year-old man with COVID-19 who presented to the fever clinic of our institution with fever and cough without any respiratory distress but low oxygen saturation. The patient deteriorated over the next 2 days but eventually recovered of his illness in due course of time. This case demonstrates 'silent hypoxia' as a possible presentation in COVID-19 and emphasises the importance of meticulous clinical examination including oxygen saturation measurements in suspected or confirmed patients.
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Case Reports |
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