Pulse Oxygen Saturation Research Articles

EPAS1 and VEGFA gene variants are related to the symptoms of acute mountain sickness in Chinese Han population: a cross-sectional study

BackgroundMore people ascend to high altitude (HA) for various activities, and some individuals are susceptible to HA illness after rapidly ascending from plains. Acute mountain sickness (AMS) is a general complaint that affects activities of daily living at HA. Although genomic association analyses suggest that single nucleotide polymorphisms (SNPs) are involved in the genesis of AMS, no major gene variants associated with AMS-related symptoms have been identified.MethodsIn this cross-sectional study, 604 young, healthy Chinese Han men were recruited in June and July of 2012 in Chengdu, and rapidly taken to above 3700 m by plane. Basic demographic parameters were collected at sea level, and heart rate, pulse oxygen saturation (SpO2), systolic and diastolic blood pressure and AMS-related symptoms were determined within 18–24 h after arriving in Lhasa. AMS patients were identified according to the latest Lake Louise scoring system (LLSS). Potential associations between variant genotypes and AMS/AMS-related symptoms were identified by logistic regression after adjusting for potential confounders (age, body mass index and smoking status).ResultsIn total, 320 subjects (53.0%) were diagnosed with AMS, with no cases of high-altitude pulmonary edema or high-altitude cerebral edema. SpO2 was significantly lower in the AMS group than that in the non-AMS group (P = 0.003). Four SNPs in hypoxia-inducible factor-related genes were found to be associated with AMS before multiple hypothesis testing correction. The rs6756667 (EPAS1) was associated with mild gastrointestinal symptoms (P = 0.013), while rs3025039 (VEGFA) was related to mild headache (P = 0.0007). The combination of rs6756667 GG and rs3025039 CT/TT further increased the risk of developing AMS (OR = 2.70, P < 0.001).ConclusionsUnder the latest LLSS, we find that EPAS1 and VEGFA gene variants are related to AMS susceptibility through different AMS-related symptoms in the Chinese Han population; this tool might be useful for screening susceptible populations and predicting clinical symptoms leading to AMS before an individual reaches HA.Trial registrationChinese Clinical Trial Registration, ChiCTR-RCS-12002232. Registered 31 May 2012.

Pulse Oximetry in Comparison to Arterial Blood Oxygen Saturation in Patients with Respiratory Distress in Neonatal Intensive Care Unit (NICU)

Background: It is essential to monitor the saturation of oxygen in newborns receiving supplemental oxygen to reduce the incidence of exposure to hyperoxemia and their potential hazardous effects of radical oxygen species. The oxygen saturation is measured by pulse oximeter which is a non-invasive tool. Arterial blood gas is used to determine the pH, PaCO2, PaO2 and the bicarbonate level. Aims and Objectives: This study aimed at searching the reliability of non-invasive pulse oximeter in knowing oxygen saturation (SpO2) in comparison with arterial blood PaO2 in neonates with respiratory distress. The primary objective was to correlate the values between partial pressure of oxygen (PaO2) and pulse oxygen saturation by pulse oximeter (SpO2).The secondary objectives were 1) To find out the efficacy of pulse oximeter in diagnosing hypoxia in comparison with PaO2. 2) To find out efficacy of pulse oximeter in diagnosing hyperoxemia in comparison with PaO2. Material and Method: Observational study was conducted on thirty neonates suffering from different causes of respiratory distress in NICU of Krishna Hospital, Karad during December 2017 to September The PaO2 measurements were obtained from the blood analyzer; simultaneous pulse oxygen saturation were recorded. Results: A significant correlation was observed between values of pulse oxygen saturation by pulse oximeter (SpO2) and partial pressure of oxygen (PaO2) by arterial blood sampling (r value -0.73, p<0.01) On ROC curve analysis, sensitivity and specificity of pulse oximetry in prediction of hypoxemia was 87.5% and 85.7% at cut-off of 90% and 91% each. The sensitivity and specificity of pulse oximetry in prediction of hyperoxemia was 100% and 71.4% at cuff-off of 94% while it was 88.9% and 76.2% at cut-off of 95% respectively. Conclusion: Pulse oximetry showed a good correlation with arterial blood PaO2. Oxygen saturation measured by pulse oximetry is a good diagnostic and prognostic tool for detecting hypoxemia and hyperoxemia.

The ratio of shock index to pulse oxygen saturation predicting mortality of emergency trauma patients.

To test the following hypothesis: the ratio of shock index to pulse oxygen saturation can better predict the mortality of emergency trauma patients than shock index. 1723 Patients of trauma admitted to the Emergency Department of the First Affiliated Hospital of Soochow University from 1 November 2016 to 30 November 2019 were retrospectively evaluated. We defined SS as the ratio of SI to SPO2, and the mortality of trauma patients in the emergency department as end-point of outcome. We calculated the crude HR of SS and adjusted HR with the adjustment for risk factors including sex, age, revised trauma score (RTS) by Cox regression model. ROC curve analyses were performed to compare the area under the curve (AUC) of SS and SI. The crude HR of SS was: 4.31, 95%CI (2.89-6.42) and adjusted HR: 3.01, 95%CI(1.86-4.88); ROC curve analyses showed that AUC of SS was higher than that of shock index (SI), and the difference was statistically significant: 0.69, 95%CI(0.55-0.83) vs 0.65, 95%CI (0.51-0.79), P = 0.001. The ratio of shock index to pulse oxygen saturation is good predictor for emergency trauma patients, which has a better prognostic value than shock index.

Guidance for the management of adult patients with coronavirus disease 2019.

In December 2019, a novel coronavirus was identified in Wuhan City, Hubei Province, China and later the disease was named coronavirus disease 2019 (COVID-19). On March 11, 2020, the World Health Organization (WHO) officially announced that COVID-19 had reached global pandemic status. This article summarized the understanding of the etiology, pathogenesis, epidemiology, clinical characteristics, diagnosis, treatment, rehabilitation, and prevention and control measures of COVID-19 based on the available data and anti-epidemic experience in China.

Effect Of Heat Acclimation On Incidence Of Acute Mountain Sickness During Exposure To Hypobaric Hypoxia (3,500 M)

INTRODUCTION: Adaptations gained from heat acclimation (HA) can induce protective responses to a different stressor, such as hypoxia. Rapid ascent to altitude (hypobaric hypoxia, HH) increases the risk for acute mountain sickness (AMS). However, it is unknown whether HA can protect against the development of AMS during exposure to HH. PURPOSE: To determine if prior HA reduces the incidence of AMS during a 30 hour exposure to HH (3,500 m). METHODS: Thirteen unacclimatized healthy men (mean ± SD; age: 21 ± 3 yr; ht: 172 ± 8 cm; wt: 75.1 ± 12.2 kg; sea level VO2peak 42.9 ± 4.6 ml·kg-1·min-1) participated in three study phases consisting of: Phase 1) baseline (pre HA) 30 hour HH exposure (HH1; 3,500 m), Phase 2) 14-day washout period during which volunteers completed an 8-day exercise-HA protocol (treadmill walking: 120 minutes at 5 km·hr-1, 2% grade; 40°C and 40% RH), and Phase 3) post HA 30 hour HH exposure (HH2). During the HA protocol, heart rate (HR) and core temperature (Tc) were recorded throughout exercise. AMS was assessed using the Environmental Symptoms Questionnaire after ~12, ~21, and ~23 hours of exposure during each HH phase. HR and pulse oxygen saturation (SpO2) were measured at rest immediately after assessment of AMS. A t-test was used to assess difference in HR and Tc from Day 1 and Day 8 of HA. For the HH exposures, HR and SpO2 data were analyzed by fitting a mixed effects model as implemented by GraphPad Prism 8.1.2. RESULTS: Heat acclimation was achieved as indicated by a lower Tc (Day 1: 38.1 ± 0.3 vs Day 8: 37.8 ± 0.3 °C; p<0.01) and HR (Day 1: 134 ± 17 vs Day 8: 121 ± 13 bpm; p<0.01) at the end of exercise on Day 8 compared to Day 1. Three of 13 volunteers developed AMS during HH1 but not during HH2. A fourth volunteer only developed AMS during HH2. From HH1 to HH2, resting HR (84 ± 6 vs 83 ± 7 bpm) and SpO2 (87 ± 2 vs 88 ± 2%) were not different (both p >0.05). CONCLUSION: Our results suggest that in unacclimatized individuals, HA may be an effective, though not perfect training strategy for reducing the incidence of AMS during rapid exposure to 3,500 m. Changes in AMS incidence could not be explained by alterations in HR or SpO2. Supported by USAMRDC; author views not official US Army or DoD policy.

Effect of new simple breathing apparatus on oxygen therapy in patients with severe and critical coronavirus disease 2019

To make a new simple respirator and observe the oxygen therapy effect of the respirator on patients with severe and critical coronavirus disease 2019 (COVID-19). Based on the infectivity and hospital requirements of COVID-19, a new simple respirator was designed by the medical staff of the Department of Anesthesiology of the Second Affiliated Hospital of Nanchang University, which was applied on the 22 patients with severe and critical COVID-19 who needed oxygen therapy admitted to the Cancer Center of Tongji Medical College of Huazhong University of Science and Technology from February 15th to March 15th in 2020. The new simple respirator contained two National Utility Model Patents (a respirator: ZL 2015 2 0410623.6, a fluid switch and oxygen suction device: ZL 2017 2 0873509.6), which was mainly composed of anesthesia mask and filter, L-shaped connecting tube, soft breathing bladder, connecting tube and elastic fixing belt. When in use, the anesthesia mask was fixed to the patient's mouth and nose with elastic straps, the connecting tube was inserted into the oxygen meter interface, the oxygen flow was adjusted to 6-10 L/min, and the L-shaped connecting tube was opened immediately after the soft breathing bag was full. The carbon dioxide and excess oxygen in the body was discharged from exhaust port. The oxygen flow was lowered to 2-3 L/min, the patient's respiratory rate (RR) was observed through the soft breathing bag fluctuations, and the oxygen flow was adjusted at any time. The changes of pulse oxygen saturation (SpO2), RR and heart rate (HR) before and after application of new simple respirator were observed, and the blood gas test results of part of the patients were collected. Twenty-two patients with severe and critical COVID-19 had significantly higher SpO2 at 10 minutes after application of the new simple ventilator than before application (0.994±0.007 vs. 0.952±0.017, P < 0.01), and RR was significantly lower than that before application (times/min: 27.59±3.63 vs. 29.64±3.81, P < 0.01); after 1 day of application, each index was further improved. All 13 patients who received blood gas analysis indicated no carbon dioxide accumulation. The new simple respirator can significantly improve the oxygen therapy effect of patients with severe and critical COVID-19. At the same time, 2019 novel coronavirus (2019-nCoV) can be filtered through the filter to reduce the formation of aerosol and protect the medical staff and patients.

Severe low cerebral oximetry in difficult cardiopulmonary bypass weaning of low body-weight infant: a case report and literature review

BackgroundFor infants undergoing complex cardiac surgery, hemodynamic management after cardiopulmonary bypass (CPB) is challenging because of severe myocardial edema, vasomotor dysfunction and weak tolerance to a change in blood volume. More importantly, the lack of availability of equipment for advanced monitoring, such as transesophageal echocardiography or transthoracic echocardiography, restricts the accurate assessment of hemodynamics.Case presentationThis is a case of severe hypotension and non-detectable pulse oxygen saturation (SpO2) after CPB in a low-weight infant who had normal blood pressure and oxygen saturation before surgery. Epinephrine and milrinone were administered with cerebral oximetry monitoring rather than blood pressure measurements because cerebral oximetry was more responsive to treatment than blood pressure. Under the guidance of cerebral oximetry, the infant was successfully weaned from CPB and recovered after surgery without adverse neurological events.ConclusionsFor infants who develop refractory hypotension and failure in SpO2 monitoring during the CPB weaning period, cerebral oximetry provides an index for assessing brain perfusion and valuable guidance for appropriate inotropic treatment.

Prevalence and Predictors of Elevated Pulmonary Artery Pressure in Nigerian Children with Sickle Cell Anaemia

Background: Sickle Cell Anaemia (SCA) is the most common inherited disorder in Nigeria. Pulmonary Hypertension (PH) is a known complication of SCA that commences from childhood and progresses as they grow older.&#x0D; Aim: To determine the prevalence and predictors of elevated pulmonary artery pressure (PAP) in children with SCA.&#x0D; Study Design: This is an analytical cross-sectional study.&#x0D; Methods: Three hundred subjects with SCA in steady state and 300 HbAA controls, aged 6 months – 15 years, were enrolled into the study. Children with SCA were recruited by simple random sampling, from the Paediatric Sickle Cell Clinic, Usmanu Danfodiyo University Teaching Hospital, Sokoto. All the children had clinical evaluation, echocardiography, full blood count and reticulocyte count. Pulmonary artery systolic pressure (PASP) and mean pulmonary artery pressure (MPAP) were determined by measurement of tricuspid regurgitant velocity (TRV) and mean gradient (MG) respectively. &#x0D; Results: Seventy-two children with SCA (24.0%) had elevated PAP (defined as TRV ≥ 2.5 m /s) while only 9 (3.0%) had pulmonary hypertension (defined as MPAP ≥ 25 mmHg). Older age (O.R = 1.03, p &lt; 0.001), high systolic blood pressure (O.R = 1.2, p = 0.01), and high reticulocyte count (O.R = 1.33, p = 0.04) were weakly associated with increased likelihood of elevated PAP. Normal pulse oxygen saturation (SPO2 ≥ 95%, O.R = 0.4, p = 0.002) and normal heart sounds on auscultation (O.R = 0.2, p = 0.04) were associated with a reduced likelihood of elevated PAP. Presence of left parasternal heave (O.R = 8.4, p = 0.001) significantly predicted elevated PAP in children with SCA.&#x0D; Conclusion: PH occurs as a complication in children with SCA and certain clinical and laboratory parameters do predict this complication in children.

Does Tai Chi improve antioxidant and anti-inflammatory abilities via the KEAP1-NRF2 pathway and increase blood oxygen level in lung cancer patients: A randomized controlled trial?

IntroductionTai Chi (TC) exercises appear to have beneficial effects for lung cancer patients. The effects of TC on blood oxygen level, and the antioxidant and anti-inflammatory activities assessed by measuring Kelch-like ECH-associated protein 1-NF-E2-related factor 2 (KEAP1-NRF2) signaling was investigated in patients who had lung cancer surgery. MethodsLung cancer patients after surgery were randomly allocated into an intervention (IG, received TC) or a control (CG, received routine nurse care) group. We measured serum oxidative factors and inflammatory cytokines, KEAP1 and NRF2 in peripheral blood leukocytes, forced expiratory volume in the first second (FEVi), forced vital capacity (FVC), pulse oxygen saturation (SPO2), and pain scores. ResultsAfter a 3-month intervention, TC appeared to significantly improve lung function by increasing the levels of KEAP1, NRF2, FVC, FEVi, and SPO2, and reducing pain scores (p < 0.05). TC increased the levels of antioxidant markers (superoxidase dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx)) and anti-inflammatory factor (interleukin (IL)-10), and reduced the levels of malondialdehyde and inflammatory markers (tumor necrosis factor α (TNFα), IL-1 and IL-6) (p < 0.05). The levels of KEAP1 and NRF2 had a strong relationship with the level of these oxidative and inflammatory markers (p < 0.05). ConclusionsAfter a 3-month intervention, TC appeared to patient’s antioxidant and anti-inflammatory abilities possibly by affecting KEAP1-NRF2 signaling, and increasing blood oxygen level. The study may have some bias as follow up was short and size sample small.

Hemoptysis complicating ultrasound-guided transthoracic needle lung biopsy: air bronchial sign is a risk predictor.

BackgroundHemoptysis is the most frequently reported complication of ultrasound-guided transthoracic needle lung biopsy (US-TTLB). However, factors influencing the occurrence of hemoptysis as a result of US-TTLB remain uncertain. Therefore, the aim of this study was to evaluate the incidence of hemoptysis as a complication of US-TTLB and to identify the related risk factors.MethodsWe retrospectively analyzed all data of patients who underwent US-TTLB from February 2013 through December 2016. The incidence, severity, and treatment of hemoptysis in each case were carefully recorded. Study variables were classified into patient-related factors (age, sex, smoking history, pulse oxygen saturation, laboratory tests and emphysema), biopsy-related factors (use of contrast agent, number of punctures and operators), and lesion-related factors (lesion location, size, pathology, length of puncture path and the grade of air bronchial sign). Univariate and multivariate logistic regression analyses were performed to analyze the risk factors of hemoptysis. We investigated whether incidence of hemoptysis increased according to increased grade of air bronchial sign by Mantel-Haenszel test.ResultsA total of 209 patients were evaluated. Hemoptysis occurred in 20 of the 209 patients (9.6%). In univariate analysis, the lesion pathology (P=0.037) and grade of air bronchial sign (P<0.001) were statistically significant factors between the hemoptysis group and the non-hemoptysis group. In multivariate analysis, the presence of multi-air bronchogram in sonographic image (odds ratio =8.946; 95% confidence interval: 2.873–27.863; P<0.001) was a statistically significant predictive risk factor for hemoptysis complicating US-TTLB. There was a significant tendency for incidence of hemoptysis with the grade of air bronchial sign (P<0.001).ConclusionsWe found that the rate of hemoptysis complicating US-TTLB was 9.6% and the severity of hemoptysis was not serious. Target lesion without air bronchogram is a safety sign, minor bronchogram means relatively low-risk, while multiple bronchogram is a highly dangerous ultrasound sign of hemoptysis.

Comparison of pulse oximetry and earlobe blood gas with CO-oximetry in children with sickle cell disease: a retrospective review

ObjectivesTo investigate the agreement between pulse oximetry (SpO2) and oxygen saturation (SaO2) measured by CO-oximetry on arterialised earlobe blood gas (EBG) in children and adolescents with sickle cell disease (SCD).Design...

Application of pump-controlled retrograde trial off in weaning from veno-arterial extracorporeal membrane oxygenation in adult patients

Objective: To Summarize the experience of pump-controlled retrograde trial off (PCRTO) in the process of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) withdrawal in adult patients. Methods: Adult patients who received ECMO assistance in Intensive Care Unit for Cardiac Surgery from March to July 2019 were collected. According to our strategies, PCRTO was used if the patients can wean from VA-ECMO and hemodynamic indexes were recorded during the process. The statistics data was collected, including the 48 hours survival rate, ECMO re-assistance rate, thrombus complications, Intensive Care Unit (ICU) stay time and hospital stay time after weaning from VA-ECMO. The patients who failed in the test were continued to be assisted by ECMO. Results: There were 46 patients assisted by VA-ECMO in our center. In total, 21 adults who met the offline test standard underwent 26 PCRTOs, including 10 male adults (47.6%), with an age of 65 (55, 68) years old. Eighteen adults passed the withdrawal test. No new thrombus was found in the arteriovenous ultrasound of the lower extremity after weaning from ECMO, and no pulmonary embolism was found in the chest X-ray. The success rate of weaning from ECMO was 69.23%(18/26). The D-dimer decreased [584(348,2 107)μg/L vs 1 440(631,2 916)μg/L, P=0.014] and the left ventricular ejection fraction (LVEF) increased (51.4%±8.5% vs 46.9%±10.6%, P=0.013) on the next day after weaning. There were significant differences in heart rate (HR), central venous pressure (CVP), oxygenation index and lactate (Lac) during the PCRTO in the group which involved the cases of the 8 failed experiments (all P<0.05). Compared with the failure group, there were significant differences in age, blood flow rate, CVP before the test, HR, pulse oxygen saturation(SpO(2)), CVP, Lac and oxygenation index after the test, and the variations of SpO(2), CVP and Lac. Conclusion: PCRTO is a simple, reversible, safe and effective weaning method. It can be used in the process of VA-ECMO withdrawal in adult patients.

Shortening Work-Rest Durations Reduces Physiological and Perceptual Load During Uphill Walking in Simulated Cold High-Altitude Conditions.

Fornasiero, Alessandro, Aldo Savoldelli, Federico Stella, Alexa Callovini, Lorenzo Bortolan, Andrea Zignoli, David A. Low, Laurent Mourot, Federico Schena, and Barbara Pellegrini. Shortening work-rest durations reduces physiological and perceptual load during uphill walking in simulated cold high-altitude conditions. High Alt Med Biol. 21:249-257, 2020. Background: We investigated the effects of two different work-rest durations on the physiological and perceptual responses to a simulated mountain hike in a cold hypoxic environment. Materials and Methods: Twelve healthy nonacclimatized active men (age 31.3 ± 5.3 years, body mass index 22.4 ± 1.5 kg/m2) completed a 80-minute work-matched intermittent exercise on a motorized treadmill (25% incline, fixed self-selected speed), in a simulated mountain environment (-25°C, FiO2 = 11%, ≈5000 m a.s.l.), wearing extreme cold weather gear, once with short (20 × 3 minutes walking with 1 minute rest; SHORT) and once with long (10 × 6 minutes walking with 2 minutes rest; LONG) work-rest durations. Heart rate (HR), pulse oxygen saturation (SpO2), rate of perceived exertion (RPE), and thermal sensation (TS) were assessed throughout the exercise protocols. Cardiac autonomic modulation was assessed before (PRE) and after exercise (POST) in supine position, as well as during standing resting periods by means of HR recovery (HRR) assessment. Results: SpO2 and TS were similar (p > 0.05) in SHORT and LONG protocols. HR and RPE were increased, and HRR reduced during LONG compared to SHORT (p < 0.05). Parasympathetic activity indices were reduced at POST after both protocols (p < 0.05), but to a lesser extent after SHORT (p < 0.05). Conclusions: Reduced work-rest durations are associated with improved perceptual responses and less perturbation of cardiac autonomic balance, compared to longer work-rest durations. Shorter exercise periods from more frequent breaks during hikes at high altitude may represent a valid strategy to limit the impact of exercise under extreme environmental conditions.

Non-invasive respiratory support for patients with novel coronavirus pneumonia: clinical efficacy and reduction in risk of infection transmission.

Non-invasive respiratory support for patients with novel coronavirus pneumonia: clinical efficacy and reduction in risk of infection transmission.

Relationship between D-dimer concentration and inflammatory factors or organ function in patients with coronavirus disease 2019

To explore the relationship between D-dimer concentration and inflammatory factors or organ function in patients with coronavirus disease 2019 (COVID-19). A retrospective study was conducted. The clinical data of 72 patients with COVID-19 admitted to intensive unit of Tongji Guanggu Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology in Wuhan, Hubei Province from February 10th to 29th in 2020 were collected, including their general information, routine blood test, coagulation function, inflammatory parameters, cytokines, and organ function related laboratory parameters at admission. The patients were divided into two groups, namely D-dimer normal group (< 0.5 mg/L) and D-dimer elevated group (≥ 0.5 mg/L). The differences of general data, inflammatory parameters and cytokines between the two groups were compared. Besides, the correlation between D-dimer and organ function was analyzed by linear regression. The change in sequential organ failure assessment (SOFA) between the first visit after the onset of the disease and admission to intensive unit ≥ 2 was defined as being combined with organ damage. Receiver operating characteristic (ROC) curve was drawn to evaluate the predictive value of D-dimer on organ damage in patients with COVID-19. 65.3% of the 72 patients had abnormal coagulation. The D-dimer level of COVID-19 patients gradually increased with the aggravation of the disease, and the levels of ordinary type (n = 14), severe type (n = 49), and critical type (n = 9) were 0.43 (0.22, 0.89), 0.66 (0.26, 1.36), and 2.65 (0.68, 15.45) mg/L, respectively, with statistically significant difference (P < 0.05). Thirty-two patients (44.4%) had normal D-dimer, and 40 (55.6%) had elevated D-dimer. Compared with the normal D-dimer group, the patients in the D-dimer elevated group were older (years old: 67.7±11.6 vs. 54.0±13.1), and the levels of white blood cell count (WBC), neutrophil count (NEU), procalcitonin (PCT), high-sensitivity C-reactive protein (hs-CRP), interleukins (IL-6, IL-8, IL-10), IL-2 receptor (IL-2R) and tumor necrosis factor-α (TNF-α) at admission were significantly higher [WBC (×109/L): 7.16 (5.55, 9.75) vs. 5.25 (4.59, 6.98), NEU (×109/L): 7.11±5.46 vs. 3.33±1.58, PCT (μg/L): 0.08 (0.06, 0.21) vs. 0.05 (0.04, 0.06), hs-CRP (mg/L): 27.9 (3.4, 58.8) vs. 1.3 (0.8, 6.6), IL-6 (ng/L): 11.80 (2.97, 30.61) vs. 1.98 (1.50, 4.73), IL-8 (ng/L): 19.90 (13.33, 42.28) vs. 9.40 (12.35, 15.30), IL-10 (ng/L): 5.00 (5.00, 8.38) vs. 5.00 (5.00, 5.00), IL-2R (kU/L): 907.90±458.42 vs. 572.13±274.55, TNF-α (ng/L): 10.94±5.95 vs. 7.77±3.67], while lymphocyte (LYM) and monocyte (MON) counts were lower [LYM (×109/L): 1.14±0.49 vs. 1.46±0.42, MON (×109/L): 0.63±0.25 vs. 0.87±0.21], with significant differences (all P < 0.05). Linear regression analysis showed that D-dimer level was negatively related with pulse oxygen saturation (SpO2), oxygenation index (PaO2/FiO2) and platelet count (PLT) with β values of -0.493, -11.615, and -0.018, respectively (all P < 0.05). However, D-dimer level was positively related with respiratory rate (RR), aspartate aminotransferase (AST), total bilirubin (TBil) and direct bilirubin (DBil) with β values of 0.485, 0.107, 0.291, and 0.404 (all P < 0.05). ROC curve analysis showed that the area under ROC curve (AUC) of D-dimer for predicting organ injury in COVID-19 patients was 0.889, and the 95% confidence interval (95%CI) was 0.753-1.000. When the optimal cut-off value was 2.36 mg/L, the sensitivity was 85.7%, and the specificity was 78.1%. D-dimer levels in COVID-19 patients are correlated with inflammatory factors and organ function, and it can be used to predict organ injury.

Case 281.

History An 18-year-old man was diagnosed with precursor B-cell lymphoblastic leukemia and underwent transplantation of hematopoietic stem cells from his human leukocyte antigen-matched sister 1 year prior to admission. He was admitted to evaluate progressive shortness of breath and dry cough of 1-month duration. He did not report fever, night sweats, or hemoptysis. Physical examination revealed he was afebrile and had normal pulse oxygen saturation. The examination revealed crepitation on palpation of the anterior neck, expiratory wheezes, and crackles heard at auscultation of bases of both lungs. Extensive maculopapular rash on the skin was consistent with graft-versus-host disease (GVHD). Laboratory tests revealed elevated liver transaminase and bilirubin levels that were attributed to liver GVHD. Nonenhanced thin-section CT of the chest was performed (Figs 1-5).

A possible role for B cells in COVID-19? Lesson from patients with agammaglobulinemia

Summary COVID-19 had a mild clinical course in patients with Agammaglobulinemia lacking B lymphocytes, whereas it developed aggressively in Common Variable Immune Deficiency. Our data offer mechanisms for possible therapeutic targets.

Investigation of Photoplethysmography Behind the Ear for Pulse Oximetry in Hypoxic Conditions with a Novel Device (SPYDR)

Photoplethysmography (PPG) is a valuable technique for noninvasively evaluating physiological parameters. However, traditional PPG devices have significant limitations in high-motion and low-perfusion environments. To overcome these limitations, we investigated the accuracy of a clinically novel PPG site using SPYDR®, a new PPG sensor suite, against arterial blood gas (ABG) measurements as well as other commercial PPG sensors at the finger and forehead in hypoxic environments. SPYDR utilizes a reflectance PPG sensor applied behind the ear, between the pinna and the hairline, on the mastoid process, above the sternocleidomastoid muscle, near the posterior auricular artery in a self-contained ear cup system. ABG revealed accuracy of SPYDR with a root mean square error of 2.61% at a 70–100% range, meeting FDA requirements for PPG sensor accuracy. Subjects were also instrumented with SPYDR, as well as finger and forehead PPG sensors, and pulse rate (PR) and oxygen saturation (SpO2) were measured and compared at various reduced oxygen profiles with a reduced oxygen breathing device (ROBD). SPYDR was shown to be as accurate as other sensors in reduced oxygen environments with a Pearson’s correlation >93% for PR and SpO2. In addition, SPYDR responded to changes in SpO2 up to 50 s faster than PPG measurements at the finger and forehead.

Hyperbaric oxygen therapy may be effective to improve hypoxemia in patients with severe COVID-2019 pneumonia: two case reports

To determine whether hyperbaric oxygen (HBO2) therapy be effective to improve hypoxemia for severe COVID-19 pneumonia patients. Two male patients ages 57 and 64 years old were treated. Each met at least one of the following criteria: shortness of breath; respiratory rate (RR) ≥30 breaths/minute; finger pulse oxygen saturation (SpO2) ≤93% at rest; and oxygen index (P/F ratio: PaO2/FiO2 ≤300 mmHg). Each case excluded any combination with pneumothorax, pulmonary bullae or other absolute contraindications to HBO2. Patients were treated with 1.5 atmospheres absolute HBO2 with an oxygen concentration of more than 95% for 60 minutes per treatment, once a day for one week. Patients' self-reported symptoms, daily mean SpO2 (SO2), arterial blood gas analysis, D-dimer, lymphocyte, cholinesterase (che) and chest CT were conducted and measured. For both patients, dyspnea and shortness of breath were immediately alleviated after the first HBO2 treatment and remarkably relieved after seven days of HBO2 therapy. The RR also decreased daily. Neither patient became critically ill. The decreasing trend of SO2 and P/F ratio was immediately reversed and increased day by day. The lymphocyte count and ratio corresponding to immune function gradually recovered. D-dimer corresponding to peripheral circulation disorders and serum cholinesterase, reflecting liver function had improved. Follow-up chest CT showed that the pulmonary inflammation had clearly subsided. Our preliminary uncontrolled case reports suggest that HBO2 therapy may promptly improve the progressive hypoxemia of patients with COVID-2019 pneumonia. However, the limited sample size and study design preclude a definitive statement about the potential effectiveness of HBO2 therapy to COVID-2019 pneumonia. It requires evaluation in randomized clinical trials in future.

Extracorporeal Membrane Oxygenation for Coronavirus Disease 2019 in Shanghai, China.

Severe cases of coronavirus disease 2019 (COVID-19) cannot be adequately managed with mechanical ventilation alone. The role and outcome of extracorporeal membrane oxygenation (ECMO) in the management of COVID-19 is currently unclear. Eight COVID-19 patients have received ECMO support in Shanghai with seven with venovenous (VV) ECMO support and one veno arterial (VA) ECMO during cardiopulmonary resuscitation. As of March 25, 2020, four patients died (50% mortality), three patients (37.5%) were successfully weaned off ECMO after 22, 40, and 47 days support, respectively, but remain on mechanical ventilation. One patient is still on VV ECMO with mechanical ventilation. The partial pressure of oxygen/fractional of inspired oxygen ratio before ECMO initiation was between 54 and 76, and all were well below 100. The duration of mechanical ventilation before ECMO ranged from 4 to 21 days. Except the one emergent VA ECMO during cardiopulmonary resuscitation, other patients were on ECMO support for between 18 and 47 days. In conclusion, ensuring effective, timely, and safe ECMO support in COVID-19 is key to improving clinical outcomes. Extracorporeal membrane oxygenation support might be an integral part of the critical care provided for COVID-19 patients in centers with advanced ECMO expertise.