scholarly journals Misconceptions of pathophysiology of happy hypoxemia and implications for management of COVID-19

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Martin J. Tobin ◽  
Amal Jubran ◽  
Franco Laghi
Keyword(s):  
Arterial Oxygen ◽  
Severe Hypoxemia ◽  
Pathophysiological Mechanisms ◽  
Oxygen Levels ◽  
Life Threatening ◽  
Therapeutic Measures ◽  
Respiratory Discomfort

AbstractIn the article “The pathophysiology of ‘happy’ hypoxemia in COVID-19,” Dhont et al. (Respir Res 21:198, 2020) discuss pathophysiological mechanisms that may be responsible for the absence of dyspnea in patients with COVID-19 who exhibit severe hypoxemia. The authors review well-known mechanisms that contribute to development of hypoxemia in patients with pneumonia, but are less clear as to why patients should be free of respiratory discomfort despite arterial oxygen levels commonly regarded as life threatening. The authors propose a number of therapeutic measures for patients with COVID-19 and happy hypoxemia; we believe readers should be alerted to problems with the authors’ interpretations and recommendations.

scholarly journals Massive haemorrhagic complications of ruptured pulmonary arteriovenous malformations: outcomes from a 12 years’ retrospective study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xu Ma ◽  
Bing Jie ◽  
Dong Yu ◽  
Ling-Ling Li ◽  
Sen Jiang
Keyword(s):  
Arteriovenous Malformations ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Hereditary Haemorrhagic Telangiectasia ◽  
Pulmonary Arteriovenous Malformations ◽  
Imaging Data ◽  
Peripheral Lung ◽  
Life Threatening ◽  
The Mean

Abstract Background The life-threatening haemorrhagic complications of pulmonary arteriovenous malformations (PAVMs) are extremely rare, and only described in isolated cases. This study was designed to comprehensively investigate management of ruptured PAVMs. Methods We retrospectively assessed clinical and imaging data of ruptured PAVMs to summarize incidence, clinical characteristics, and outcomes following embolisation between January 2008 and January 2021. Results Eighteen of 406 (4.4%) patients with PAVMs developed haemorrhagic complications. Twelve of 18 patients were clinically diagnosed with hereditary haemorrhagic telangiectasia (HHT). Haemorrhagic complications occurred with no clear trigger in all cases. Eight of 18 patients (44.4%) were initially misdiagnosed or had undergone early ineffective treatment. 28 lesions were detected, with 89.3% of them located in peripheral lung. Computed tomography angiography (CTA) showed indirect signs to indicate ruptured PAVMs in all cases. Lower haemoglobin concentrations were associated with the diameter of afferent arteries in the ruptured lesions. Successful embolotherapy was achieved in all cases. After embolotherapy, arterial oxygen saturation improved and bleeding was controlled (P < 0.05). The mean follow-up time was 3.2 ± 2.5 years (range, 7 months to 10 years). Conclusions Life threatening haemorrhagic complications of PAVMs are rare, they usually occur without a trigger and can be easily misdiagnosed. HHT and larger size of afferent arteries are major risk factors of these complications. CTA is a useful tool for diagnosis and therapeutic guidance for ruptured PAVMs. Embolotherapy is an effective therapy for this life-threatening complication.

scholarly journals Characteristics, Treatment, and Outcomes of Patients With Severe or Life-threatening COVID-19 at a Military Treatment Facility—A Descriptive Cohort Study

2021 ◽  
Author(s):  
Brian P Elliott ◽  
Gregory M Buchek ◽  
Matthew T Koroscil
Keyword(s):  
Severe Disease ◽  
Ambient Air ◽  
Active Duty ◽  
Urban Setting ◽  
Arterial Oxygen ◽  
Treatment Facility ◽  
Blood Oxygen Saturation ◽  
Life Threatening ◽  
Military Treatment Facility ◽  
Active Duty Personnel

ABSTRACT Introduction The treatment of severe and life-threatening COVID-19 is a rapidly evolving practice. The purpose of our study was to describe the characteristics and outcomes of patients with severe or life-threatening COVID-19 who present to a Military Treatment Facility (MTF) with an emphasis on addressing institutional adaptations to rapidly changing medical evidence. Materials and Methods A single-center retrospective study conducted on a prospectively maintained cohort. The MTF is a 52-bed hospital within an urban setting. Patients were included in the cohort if they had laboratory-confirmed severe or life-threatening COVID-19 with positive SARS-CoV-2 reverse transcription polymerase chain reaction. Severe disease was defined as dyspnea, respiratory frequency ≥30/min, blood oxygen saturation ≤93% on ambient air, partial pressure of arterial oxygen to fraction of inspired oxygen ratio &lt;300, or lung infiltrates involving &gt;50% of lung fields within 24-48 hours. Life-threatening COVID-19 was defined as respiratory failure, septic shock, or multiple organ dysfunction. The cohort included patients admitted from June 1 through November 13. Data were collected retrospectively via chart review by a resident physician. Results In total, our MTF saw 14 cases of severe or life-threatening COVID-19 from June 1 to November 13. Patients had a median age of 70.5 years, with 7% being active duty personnel, 21% dependents, and 71% retired military members. The median time to dexamethasone, remdesivir, and convalescent plasma administration was 4.7, 6.3, and 11.2 hours, respectively. The 28-day in-hospital mortality was 0%. Conclusions Patients who present to an MTF with severe or life-threatening COVID-19 are largely retirees, with only a small fraction comprising active duty personnel. The institution of order sets and early consultation can help facilitate prompt patient care for COVID-19.

scholarly journals Gluteal artery injuries including pseudoaneurysm associated with powered bone marrow biopsies

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Aditi P. Singh ◽  
Gopichand Pendurti ◽  
Shashi Singh ◽  
Alexander Shestopalov ◽  
Thomas Pacello ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Minimal Risk ◽  
Safe Procedure ◽  
Bone Marrow Biopsies ◽  
Fundamental Component ◽  
Current Review ◽  
Life Threatening ◽  
Therapeutic Measures ◽  
Life Threatening Complication ◽  
The U.S

The bone marrow procedure (BMP) is a frequently performed procedure, with over 700,000 recorded in the U.S. annually. It is a fundamental component in the evaluation and management of both malignant and benign hematologic conditions. Adult patients are generally assured that the BMP is a safe procedure with minimal risk, albeit briefly painful. Traditionally performed using a manual Jamshidi needle, the procedure is increasingly being performed using powered bone marrow kits, which have shown consistently good results. In the current review we describe three cases of gluteal artery injuries following the powered driver procedure, one of which resulted in the formation of a pseudoaneurysm requiring radiology-guided intervention. We highlight the need for both hematologists and patients to be aware of this potentially life threatening complication as well as how to recognize it clinically and institute timely diagnostic and therapeutic measures.

scholarly journals Stridor in infant caused by subglottic hemangiome: case report

2020 ◽  
Vol 10 (3) ◽  
Author(s):  
Raquel Lot ◽  
Caroline Rosa ◽  
Camila Freitas ◽  
Gracinda Adnet ◽  
Luisa Costa ◽  
...  
Keyword(s):  
Beta Agonist ◽  
First Year ◽  
Vascular Neoplasms ◽  
Threatening Condition ◽  
Life Threatening ◽  
Diagnostic Hypothesis ◽  
Therapeutic Measures ◽  
The Right ◽  
First Year Of Life ◽  
Age Range

Subglottic hemagioma is a rare cause of stridor, but it is one of the most common vascular neoplasms of the airways in childhood. If the treatment is not promptly instituted, it becomes a life-threatening condition. The diagnosis should be suspected when infants outside the age range for acute laryngitis present with stridor associated with severe respiratory effort, without viral prodromes, with a condition that is not responsive to initial therapeutic measures considering the main diagnostic hypothesis. Infantile hemangiomas begin to proliferate during the first year of life (between the 1st and 2nd month of life). Involution usually occurs between 6 months and 12 months of life (most involution until 4 years). The case is a 5-month-old female infant, with sudden stridor associated with respiratory distress without viral prodromes or fever, with little response to inhaled short-acting beta-agonist, inhaled adrenaline, as well as corticosteroids inhalation/parenteral. Bronchoscopy showed a bulging of the submucosa to the right of the subglottis with slight vascularization, suggestive of subglottic hemangioma. Treatment with propranolol was initiated orally with the aim of regressing the hemangioma and after clinical stability, the infant was discharged with outpatient follow-up.

Epileptic Seizure-Induced Hypoxemia in Infants with Apparent Life-Threatening Events

PEDIATRICS ◽  
1994 ◽  
Vol 94 (2) ◽  
pp. 148-156
Author(s):  
John Hewertson ◽  
Martin P. Samuels ◽  
David P. Southall ◽  
Christian F. Poets ◽  
Stewart G. Boyd ◽  
...  
Keyword(s):  
Median Duration ◽  
Epileptic Seizure ◽  
Sinus Tachycardia ◽  
Partial Seizures ◽  
Severe Hypoxemia ◽  
Life Threatening ◽  
Electrocardiogram Ecg ◽  
Electroencephalogram Eeg ◽  
Normal Standard ◽  
Median Interval

Objective. To describe the physiologic changes that occur during epileptic seizure (ES)-induced apparent life-threatening events (ALTE) and to provide an explanation for the mechanism whereby the hypoxemia characterizing these events occurred. Patients and design. Six infants were retrospectively selected from a group of 17 because they had ALTE documented on physiologic recordings where the first change in signals was in the electroencephalogram (EEG). The 17 infants had clinical features suggestive of partial seizures (but normal standard EEGs) and were from a sample of 172 infants with recurrent ALTE. All 17 infants underwent continuous recordings of breathing, electrocardiogram (ECG), oxygenation, and EEG, but only in 6 was an ES-induced ALTE recorded and the physiologic changes described. Results. Twenty-three ALTE were documented in six infants. Events commenced with an abnormality in the EEG, followed by a decrease in SaO2 after a median interval of 27 seconds (range 2 to 147). Despite resuscitation, the median duration of severe hypoxemia (SaO2 ≤60%) was 40 seconds (range 8 to 74). In 18 events (five infants) there was a median of four apneic pauses (range 1 to 9) preceding the decrease in SaO2 by a median duration of 24 seconds (range 3 to 48). The longest apneic pause per event lasted a median of 19 seconds (range 8 to 47). Breathing movements continued in five events (four infants), and expiratory airflow in one. Sinus tachycardia was found in 19 of the 23 events (six infants), but there were no cardiac arrhythmias. Conclusions. ES in infants can manifest as ALTE and be accompanied by potentially life-threatening episodes of severe hypoxemia and apnea, despite a normal EEG between events.

scholarly journals Schistosomiasis-associated pulmonary arterial hypertension: a systematic review

2020 ◽  
Vol 29 (155) ◽  
pp. 190089 ◽  
Author(s):  
Daniela Knafl ◽  
Christian Gerges ◽  
Charles H. King ◽  
Marc Humbert ◽  
Amaya L. Bustinduy
Keyword(s):  
Systematic Review ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Transforming Growth Factor ◽  
Meta Analysis ◽  
Signalling Pathway ◽  
Pathophysiological Mechanisms ◽  
Clinical Registries ◽  
Life Threatening ◽  
Pulmonary Arterial

Schistosomiasis-associated pulmonary arterial hypertension (Sch-PAH) is a life-threatening complication of chronic hepatosplenic schistosomiasis. It is suggested to be the leading cause of pulmonary arterial hypertension (PAH) worldwide. However, pathophysiological data on Sch-PAH are scarce. We examined the hypothesis that there are pronounced similarities in pathophysiology, haemodynamics, and survival of Sch-PAH and idiopathic PAH (iPAH).This systematic review and meta-analysis was registered in the PROSPERO database (identifier CRD42018104066). A systematic search and review of the literature was performed according to PRISMA guidelines for studies published between 01 January 1990 and 29 June 2018.For Sch-PAH, 18 studies evaluating pathophysiological mechanisms, eight studies on haemodynamics (n=277), and three studies on survival (n=191) were identified. 16 clinical registries reporting data on haemodynamics and survival including a total of 5792 patients with iPAH were included for comparison. Proinflammatory molecular pathways are involved in both Sch-PAH and iPAH. The transforming growth factor (TGF)-β signalling pathway is upregulated in Sch-PAH and iPAH. While there was no difference in mean pulmonary artery pressure (54±17 mmHg versus 55±15 mmHg, p=0.29), cardiac output (4.4±1.3 L·min−1versus 4.1±1.4 L·min−1, p=0.046), and cardiac index (2.6±0.7 L·min−1·m−2versus 2.3±0.8 L·min−1·m−2, p<0.001) were significantly higher in Sch-PAH compared to iPAH, resulting in a lower pulmonary vascular resistance in Sch-PAH (10±6 Woods units versus 13±7 Woods units, p<0.001). 1- and 3-year survival were significantly better in the Sch-PAH group (p<0.001).Sch-PAH and iPAH share common pathophysiological mechanisms related to inflammation and the TGF-β signalling pathway. Patients with Sch-PAH show a significantly better haemodynamic profile and survival than patients with iPAH.

scholarly journals Inhaled Nitric Oxide as an Adjunct to Thrombolytic Therapy in a Patient with Submassive Pulmonary Embolism and Severe Hypoxemia

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Omesh Toolsie ◽  
Umut Gomceli ◽  
Gilda Diaz-Fuentes
Keyword(s):  
Nitric Oxide ◽  
Right Ventricular ◽  
Alcohol Intoxication ◽  
Main Pulmonary Artery ◽  
Arterial Oxygen Tension ◽  
Inhaled Nitric Oxide ◽  
Arterial Oxygen ◽  
Pulmonary Emboli ◽  
Severe Hypoxemia ◽  
Submassive Pulmonary Embolism

Introduction. Inhaled nitric oxide (iNO) is a selective pulmonary vasodilator with limited indications in adults. We present a patient with hypoxemia and right ventricular dysfunction due to submassive acute pulmonary emboli where iNO was used as a bridge to thrombolysis. Case. A 29-year-old male was admitted to the intensive care unit (ICU) for alcohol intoxication complicated with aspiration pneumonia and acute respiratory failure requiring mechanical ventilation. His medical history included morbid obesity (BMI 43) and alcohol dependence syndrome. Nine days after admission, he developed severe acute hypoxia and tachycardia with arterial oxygen tension (PaO2) of 52 mmHg requiring a positive end-expiratory pressure (PEEP) of 14 cmH2O and fraction of inspired oxygen (FiO2) of 1. Chest computed tomography (CT) revealed a large embolus in the right main pulmonary artery and transthoracic echocardiogram (TTE) reported new right ventricular dilatation with decreased right ventricular function. Due to the severe hypoxemia, he was started on iNO via the breathing circuit of the ventilator at a concentration of 20 parts per million (ppm) with steady improvement in oxygenation after 1 hour with a PaO2 of 81 mmHg on the same ventilator setting. The patient was given thrombolysis with alteplase and the iNO was slowly tapered off during the subsequent four days with concomitant successful tapering of PEEP to 8 cmH2O and FiO2 of 0.45. Conclusion. Inhaled NO has been used to improve ventilation-perfusion matching and also to reduce pulmonary vascular resistance (PVR). Its effects on PVR may be useful in the setting of acute pulmonary emboli where vascular obstruction and vasoconstriction contribute to increased pulmonary arterial pressure and PVR which can present as acute right heart failure. We suggest that iNO, if available, could be considered in those patients with acute pulmonary emboli associated with significant hypoxemia as an adjunctive therapy or bridge to thrombolysis or thrombectomy.

scholarly journals Arterial Oxygenation in Traumatic Brain Injury—Relation to Cerebral Energy Metabolism, Autoregulation, and Clinical Outcome

2020 ◽  
pp. 088506662094409
Author(s):  
Teodor Svedung Wettervik ◽  
Henrik Engquist ◽  
Timothy Howells ◽  
Samuel Lenell ◽  
Elham Rostami ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Energy Metabolism ◽  
Clinical Outcome ◽  
Arterial Oxygen ◽  
Arterial Oxygenation ◽  
Post Injury ◽  
Cerebral Energy Metabolism ◽  
Oxygen Levels ◽  
Pressure Autoregulation

Background: Ischemic and hypoxic secondary brain insults are common and detrimental in traumatic brain injury (TBI). Treatment aims to maintain an adequate cerebral blood flow with sufficient arterial oxygen content. It has been suggested that arterial hyperoxia may be beneficial to the injured brain to compensate for cerebral ischemia, overcome diffusion barriers, and improve mitochondrial function. In this study, we investigated the relation between arterial oxygen levels and cerebral energy metabolism, pressure autoregulation, and clinical outcome. Methods: This retrospective study was based on 115 patients with severe TBI treated in the neurointensive care unit, Uppsala university hospital, Sweden, 2008 to 2018. Data from cerebral microdialysis (MD), arterial blood gases, hemodynamics, and intracranial pressure were analyzed the first 10 days post-injury. The first day post-injury was studied in particular. Results: Arterial oxygen levels were higher and with greater variability on the first day post-injury, whereas it was more stable the following 9 days. Normal-to-high mean pO2 was significantly associated with better pressure autoregulation/lower pressure reactivity index ( P = .02) and lower cerebral MD-lactate ( P = .04) on day 1. Patients with limited cerebral energy metabolic substrate supply (MD-pyruvate below 120 µM) and metabolic disturbances with MD-lactate-/pyruvate ratio (LPR) above 25 had significantly lower arterial oxygen levels than those with limited MD-pyruvate supply and normal MD-LPR ( P = .001) this day. Arterial oxygenation was not associated with clinical outcome. Conclusions: Maintaining a pO2 above 12 kPa and higher may improve oxidative cerebral energy metabolism and pressure autoregulation, particularly in cases of limited energy substrate supply in the early phase of TBI. Evaluating the cerebral energy metabolic profile could yield a better patient selection for hyperoxic treatment in future trials.

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