Capillary Oxygen Research Articles

Cardiac stroke volume in females and its correlation to blood volume and cardiac dimensions.

We aimed to continuously determine the stroke volume (SV) and blood volume (BV) during incremental exercise to evaluate the individual SV course and to correlate both variables across different exercise intensities. Twenty-six females with heterogeneous endurance capacities performed an incremental cycle ergometer test to continuously determine the oxygen uptake (V̇O2), cardiac output (Q̇) and changes in BV. Q̇ was determined by impedance cardiography and resting cardiac dimensions by 2D echocardiography. Hemoglobin mass and BV were determined using a carbon monoxide-rebreathing method. V̇O2max ranged from 32 to 62 mL·kg−1·min−1. Q̇max and SVmax ranged from 16.4 to 31.6 L·min−1 and 90–170 mL, respectively. The SV significantly increased from rest to 40% and from 40% to 80% V̇O2max. Changes in SV from rest to 40% V̇O2max were negatively (r = −0.40, p = 0.05), between 40% and 80% positively correlated with BV (r = 0.45, p < 0.05). At each exercise intensity, the SV was significantly correlated with the BV and the cardiac dimensions, i.e., left ventricular muscle mass (LVMM) and end-diastolic diameter (LVEDD). The BV decreased by 280 ± 115 mL (5.7%, p = 0.001) until maximum exercise. We found no correlation between the changes in BV and the changes in SV between each exercise intensity. The hemoglobin concentration [Hb] increased by 0.8 ± 0.3 g·dL−1, the capillary oxygen saturation (ScO2) decreased by 4.0% (p < 0.001). As a result, the calculated arterial oxygen content significantly increased (18.5 ± 1.0 vs. 18.9 ± 1.0 mL·dL−1, p = 0.001). A 1 L higher BV at V̇O2max was associated with a higher SVmax of 16.2 mL (r = 0.63, p < 0.001) and Q̇max of 2.5 L·min−1 (r = 0.56, p < 0.01). In conclusion, the SV strongly correlates with the cardiac dimensions, which might be the result of adaptations to an increased volume load. The positive effect of a high BV on SV is particularly noticeable at high and severe intensity exercise. The theoretically expected reduction in V̇O2max due to lower SV as a consequence of reduced BV is apparently compensated by the increased arterial oxygen content due to a higher [Hb].

Correlation between oxygen saturation of patient and severity index of COVID-19 pneumonia on CT.

Objective: To investigate the correlation between capillary blood oxygen saturation and Computerized tomography (CT) severity index in patients with Covid-19 pneumonia. Study Design: Cross Sectional study. Setting: Ibne-sina Hospital Multan Medical &amp; Dental College Multan. Period: 1st June 2020 to 1st June 2021. Material &amp; Methods: A cross-sectional analytical study was conducted at the COVID-19 ward of Ibne-sina hospital Multan Medical &amp; Dental College Multan for 1 year. At the time of admission, all capillary oxygen saturation of all the included patients was measured. Pulmonary CT scans were then performed on these patients and CT severity index was calculated. SPSS was used for data analysis. Results: A total of 170 COVID-19 infected patients were included in the study. At the time of admission, the mean oxygen saturation was found to be 88.9% ± 6.53%. Whereas, the mean severity index was15.01 ± 7.79. 22 patients had hypoxia when presented in hospital and a significantly high iCT severity index was found in these patients (p=0.001). Chronic obstructive pulmonary disease (COPD), hypertension, and diabetes were significantly related to reduced blood oxygen saturation (p&lt;0.05). Whereas, patients with hypertension had significantly raised CT scores. A significant inverse correlation was found between capillary oxygen saturation and CT severity index (r = −0.41, p &lt; 0.01). Conclusions: The study revealed a significant inverse correlation between capillary oxygen saturation and CT severity index. Moreover, it was found that underlying commodities (I.e past medical history) can also affect the CT severity index.

Current Use of Baricitinib in COVID-19 Treatment and Its Future: An Updated Literature Review.

The levels of infectivity and mortality that ensued due to the coronavirus disease 2019 (COVID-19) pandemic caused an apparent global outcry. The health system, burdened by increasing deaths and hospitalizations, sought more effective treatment. This necessitated scientists and researchers to utilize existing drugs such as baricitinib, which has proved itself as anti-inflammatory and immunomodulatory. A qualitative systematic review was conducted using databases such as Google Scholar, Science Direct, PubMed, and BioMed Central to locate relevant articles published from 2019 onward on the effectiveness of baricitinib. After evaluation of the full-text articles, 16 were selected for review. Overall, baricitinib was seen as beneficial in decreasing respiratory failure and the use of mechanical ventilation, also preventing deterioration of COVID-19 symptoms. When used as a single agent or combined with other drugs, baricitinib improves the peripheral capillary oxygen saturation (SpO2)/fraction of inspired oxygen (FiO2) ratio. The drug does not introduce any major side effects, but a mild increase in liver enzymes has been observed. Baricitinib proves to be a safe and effective treatment for COVID-19. Administered as monotherapy or in conjunction with other drugs, baricitinib provides tremendous clinical benefit to infected patients and shows good potential in terms of efficacy for future COVID-19 regimens.

Human ocular surface microcirculation quantified by in vivo computer assisted video microscopy and diffuse reflectance spectroscopy

Non-invasive imaging techniques are increasingly used to objectively quantify anterior segment structures of the eye. In this study, we apply the novel oxygen delivery index (ODIN) concept that, quantifies microvascular capacity for oxygen delivery, to the ocular surface in healthy humans.The purpose of the study was to test the applicability of the technologies used for data acquisition from the human ocular surface. We also validated whether the ODIN concept has sufficient sensitivity to detect and differentiate between microvascular structure and function in limbal and bulbar conjunctiva.Multiple ocular surface measurements using computer-assisted video microscopy (field of view: 1.6 mm × 0.9 mm) and diffuse reflectance spectroscopy (measuring volume: ∼0.1 mm3) were obtained from limbal and bulbar conjunctiva in 20 healthy volunteers. Three parameters were extracted during analyses: Functional capillary density, capillary flow velocity, and microvascular oxygen saturation.Functional capillary density was higher at limbus than in bulbar conjunctiva (11.2 ± 1.8 c/mm versus 5.2 ± 1.2 c/mm, p < 0.01), and microvascular oxygen saturation was lower at limbus (77 ± 8%) as compared to bulbar conjunctiva (89 ± 6%), p < 0.01. More than 80% of scored capillaries had continuous blood flow and no difference was seen between the recording sites (p = 0.68).In conclusion, the ODIN concept is applicable for the assessment of human ocular surface microvascular function and has sufficient sensitivity to detect increased capillary density and oxygen extraction at limbus as compared with bulbar conjunctiva.

The Association of Seasonal Variations and COVID-19 Clinical Features: A Comparative Study on the Fourth and Fifth Waves.

The COVID-19 pandemic has overwhelmed many healthcare systems. Seasonality is a feature of several infectious diseases. Studies regarding the association of seasonal variations and COVID-19 have shown controversial results. Therefore, we aimed to compare COVID-19 characteristics and survival outcomes between the fourth and fifth waves in Iran, which corresponded to spring and summer, respectively. This is a retrospective study on the fourth and fifth COVID-19 waves in Iran. One hundred patients from the fourth and 90 patients from the fifth wave were included. Data from the baseline and demographic characteristics, clinical, radiological, and laboratory findings, and hospital outcomes were compared between the fourth and fifth COVID-19 waves in hospitalized patients in Imam Khomeini Hospital Complex, Tehran, Iran. The fifth wave patients were more likely to present with gastrointestinal symptoms than the patients from the fourth wave. Moreover, patients in the fifth wave had lower arterial oxygen saturation on admission (88% vs. 90%; P = 0.026), lower levels of WBCs (neutrophils and lymphocytes) (6300.00 vs. 8000.00; P = 0.004), and higher percentages of pulmonary involvement in the chest CT scans (50% vs. 40%; P < 0.001). Furthermore, these patients had longer hospital stays than their fourth-wave counterparts (7.00 vs. 5.00; P < 0.001). Our study indicated that patients in the summer COVID-19 wave were more likely to present with gastrointestinal symptoms. They also experienced a more severe disease in terms of peripheral capillary oxygen saturation, percentages of pulmonary involvement in CT scans, and length of hospital stay.

Accuracy of Oxygen Saturation Measurements in Patients with Obesity Undergoing Bariatric Surgery.

We aimed to determine the magnitude, direction, and influencing factors of the concordance between arterial oxygen saturation (SaO2) and peripheral capillary oxygen saturation (SpO2) in patients with obesity undergoing bariatric surgery, supporting the measurement of SaO2 and SpO2 in key populations. Patients with obesity undergoing bariatric surgery from 2017 to 2020 were included. Preoperative SpO2 and SaO2 were collected. Linear correlation and multiple linear regression analyses were performed to characterize the relationships between body mass index (BMI), age, and sex with pulse oximetry and arterial blood gas (ABG) parameters. Bland-Altman analysis was applied to determine the concordance between SpO2 and SaO2 and the limits of this concordance. A total of 134 patients with obesity undergoing bariatric surgery were enrolled. SaO2 was negatively associated with BMI (p < 0.0001) and age (p = 0.006), and SpO2 was negatively associated with BMI (p = 0.021) but not with age. SpO2 overestimated SaO2 in 91% of patients with a bias of 2.05%. This bias increased by 203% in hypoxemic patients compared with nonhypoxemic patients (p < 0.0001). The bias was 1.3-fold higher (p = 0.023) in patients with a high obesity surgery mortality risk score (OS-MRS) than in those with low or intermediate scores. Compared with SpO2, preoperative SaO2 can more accurately reflect the real oxygen saturation in patients with obesity undergoing bariatric surgery, especially for those with BMI ≥ 40kg/m2, age ≥ 40years, and high OS-MRS. ABG analysis can provide a more reliable basis for accurate and timely monitoring, ensuring the perioperative safety of susceptible patients.

Correlation between Oxygen Saturation of patient and Severity Index of Covid 19 Pneumonia on CT

Aim: To investigate the correlation between capillary blood oxygen saturation and Computerized tomography (CT) severity index in patients with Covid-19 pneumonia. Study design: A cross sectional study design Setting &amp; duration: Ibne-sina hospital Multan Medical &amp; Dental College Multan, from 1st June 2020 to 1st June 2021 Methods: A cross-sectional analytical study was conducted at the COVID-19 ward of Ibne-sina hospital Multan Medical &amp; Dental College Multan for 1 year. At the time of admission, all capillary oxygen saturation of all the included patients was measured. Pulmonary CT scans were then performed on these patients and CT severity index was calculated. SPSS was used for data analysis. Results: A total of 170 Covid-19 infected patients were included in the study. At the time of admission, the mean oxygen saturation was found to be 88.9%±6.53%. Whereas, the mean severity index was15.01±7.79. 22 patients had hypoxia when presented in hospital and a significantly high iCT severity index was found in these patients (p=0.001). Chronic obstructive pulmonary disease (COPD), hypertension, and diabetes were significantly related to reduced blood oxygen saturation (p&lt;0.05). A significant inverse correlation was found between capillary oxygen saturation and CT severity index (r= −0.41, p&lt; 0.01). Conclusions: The study revealed a significant inverse correlation between capillary oxygen saturation and CT severity index. Moreover, it was found that underlying commodities (i.e., past medical history) can also affect the CT severity index. Keywords: Covid-19, hypoxia, capillary oxygen saturation, Chest CT, CT severity index.

Diaphragmatic Thickness in Chronic Obstructive Pulmonary Disease

Background: Chronic obstructive pulmonary disease, characterized by chronic airway inflammation and progressive airflow limitation, and is considered as common, preventable and treatable disease. The defining standard values for diaphragm thickness and thickening ratio using B-mode ultrasound may provide a simpler, safer means of evaluating diaphragmatic function in chronic obstructive pulmonary disease patients. Objective: to assess the diaphragmatic structure and function using B-mode ultrasonography studying the diaphragm muscle inspiratory and expiratory thickness and thickening fraction in patients with COPD compared to healthy controls, and to study their sensitivity and specificity as well as their correlation with certain pathophysiologic parameters namely (peripheral capillary oxygen saturation, body mass index and C-reactive protein) to establish possible relation with the pathophysiology of the disease. Materials and Methods: The present study is a case control study was conducted in Al-Imamein Al-Kadhimein Medical City, Baghdad, Iraq in the period extended from November 2019 to October 2021. Forty patients with the diagnosis of COPD underwent B-mode ultrasound analysis. Three images were captured both at end expiration (Tmin) and at maximal inspiration (Tmax). The thickening fraction was calculated as (Tmax-Tmin/Tmin), and each set of values was averaged. Findings were compared with a database of 40 healthy control subjects. Results: Diaphragm thickness and thickening fraction were significantly higher in COPD patients compared to control subjects with the mean of the Rt. inspiratory diaphragmatic thickness equals (3.23 ± 0.68mm versus 2.8 ± 0.55mm; respectively, p=0.006) compared to control, and (2.44 ± 0.71 versus 1.96 ± 0.6; respectively, p=0.004) for the mean Rt. diaphragmatic thickening fraction, while the mean of the Lt. inspiratory diaphragmatic thickness was (3.22 ± 0.63mm versus 2.79 ± 0.51mm; respectively, p=0.003) compared to control, and (2.45 ± 0.63 versus 1.95 ± 0.54; respectively, p=0.003) for the mean Lt. diaphragmatic thickening fraction, ROC analysis shows that the right and left diaphragmatic fractions had the highest sensitivity and specificity parameter for COPD. No correlations were found between body mass index, SpO2 with diaphragmatic parameters. Conclusion: the current study found diaphragmatic ultrasonographic characteristics in patients with COPD show significant increase in inspiratory thickness and thickening fraction compared to control group, yet they were of low diagnostic accuracy.

Anesthetic Effect of Dexmedetomidine in Clinical Functional Neurosurgery.

Background Dexmedetomidine is a highly selective and efficient α2-adrenoceptor agonist with good antianxiety, analgesic, hypnotic, and sedative effects without causing respiratory depression. Aim To investigate the anesthetic effect of dexmedetomidine in clinical neurosurgery. Methods A total of 94 patients who received functional neurosurgical treatment in our hospital from March 2019 to October 2020 were selected and divided into the study and control groups. Routine anesthesia was adopted in the control group, while dexmedetomidine was used in the study group. Perioperative hemodynamic indicators such as mean arterial pressure, heart rate, and peripheral capillary oxygen saturation, cognitive function score, pain score VAS, stress response index level, and incidence of adverse reactions were compared between the two groups. Results Before surgery (T0), no significant differences in MAP, HR, and SpO2 were observed between the two groups. However, at the beginning of the operation (T1), 30 min after the operation (T2), and immediately after the operation (T3), these indicators in the study group were significantly higher than in the control group. The postoperative MMSE of the study group 3 d later was significantly higher than that of the control group. The VAS scores after the operation of the study group were lower than those of the control group. The serum cortisol (COR) and aldosterone (ALD) levels in the study group were not significantly different from those in the control group before surgery. The levels of each index in the two groups were higher than those before and 24 h after surgery. The incidence rate of adverse reactions in the study group was lower. Conclusion The application of dexmedetomidine in clinical functional neurosurgery is safe and can maintain hemodynamic stability and reduce the degree of stress response, cognitive impairment, and pain caused by invasive surgery.

Interleaved Optical Coherence Tomography: Clinical and Laboratory Biomarkers in Patients with Diabetic Macular Edema.

(1) Background: The global burden of diabetes mellitus (DM) has been estimated to reach 600 million patients worldwide by 2040. Approximately 200 million people will develop diabetic retinopathy within this time frame. Diabetic macular edema (DME) is a severe, vision-threatening complication that can develop at any stage of diabetic retinopathy, and it represents the main cause of vision loss in patients with DM. Its harmful consequences on visual function could be prevented with timely recognition and treatment. (2) Methods: This study assessed the clinical (demographic characteristics, diabetic evolution, and systemic vascular complications); laboratory (glycated hemoglobin, metabolic parameters, capillary oxygen saturation, and renal function); ophthalmologic exam; and spectral-domain optical coherence tomography (SD–OCT) (macular volume, central macular thickness, maximal central thickness, minimal central thickness, foveal thickness, superior inner, inferior inner, nasal inner, temporal inner, inferior outer, superior outer, nasal outer, and temporal outer thicknesses, disruption of the ellipsoid zone, and disruption of the inner retinal layers (DRIL) parameters in three groups of individuals: healthy controls (HC), patients with DME and type 1 DM (T1DM—group A), and patients with DME and type 2 DM (T2DM—group B) to identify novel correlations between them that would open a path to new pathogenetic hypotheses and, implicitly, to the identification of new therapeutic methods, as part of a tailored treatment within the concept of precision medicine. (3) Results: The duration of DM was significantly longer in group A as compared with group B, as were the prevalence of smoking and systemic vascular complications. Capillary oxygen saturation and estimated glomerular filtration rates were significantly lower, and serum creatinine levels were significantly higher in group A as compared to group B. Regarding the OCT findings, DME had a predominantly eccentric pattern, and the right eye was more severely affected in both groups of patients. Significantly higher values were obtained in group B as compared to group A for the following OCT biomarkers: macular volume, central macular thickness, maximal central thickness, minimal central thickness, foveal thickness, superior inner, inferior inner, nasal inner, inferior outer and nasal outer thickness. The disruption of the ellipsoid zone was significantly more prevalent within group A, whereas the overall disruption of the retinal inner layers (DRIL) was identified significantly more frequently in group B. (4) Conclusions: Whereas systemic and laboratory biomarkers were more severely affected in patients with DME and T1DM, the OCT quantitative biomarkers revealed significantly higher values in patients with DME and T2DM.

Clamping Skeletal Muscle PO2 Eliminates Hyperinsulinemic Microvascular Blood Flow Response

ObjectiveTo determine if insulin mediated hyperemia is partially dependent on local muscle oxygen concentration.HypothesisThe blood flow responses to insulin are partially mediated by the local metabolic demand reflecting the increased oxygen consumption required to uptake and convert glucose into glycogen in skeletal muscle.Methods16 male Sprague Dawley rats (161g ‐ 204g) were anesthetized with sodium pentobarbital, the carotid artery and jugular vein were then cannulated for blood pressure monitoring and fluid resuscitation. Following cannulation, the extensor digitorum longus (EDL) was isolated and reflected onto an inverted microscope. Intravital video microscopy sequences of the EDL microcirculation were recorded during baseline and following hyperinsulinemic euglycemia or sham in all experiments. The muscle was reflected over a glass stage insert during Experiment 1a and 1b which allowed for direct observation of microvascular blood flow response to systemic insulin infusion in Experiment 1a. Experiment 1b consisted of a sham hyperinsulinemic euglycemic clamp which involved infusing saline at similar rates as insulin and glucose in standard clamp procedures. In Experiment 2, the EDL was reflected over a gas exchange chamber and microvascular capillary blood flow was recorded during sequential changes (7%‐12%‐2%‐7%) of oxygen concentration [O2] within the chamber during baseline and euglycemic conditions. The gas exchange chamber is fitted into the stage of an inverted microscope that interfaces directly with the EDL via a gas permeable polydimethylsiloxane membrane. By adjusting the concentration of gases flowing through the gas exchange chamber we have direct control of the [O2] within the overlying muscle. Hemodynamic measurements including capillary red blood cell (RBC) velocity, supply rate (SR), hematocrit, and oxygen saturation (SO2) were taken from in focus capillaries in the EDL during each experiment and analyzed offline using custom MATLAB software. All animal protocols were approved by Memorial University’s Institutional Animal Care Committee.ResultsIn Experiment 1a, the hyperinsulinemic euglycemic clamp caused a significant increase in SR from 8.9 ± 3.1 to 14.2 ± 4.9 cells/s at baseline to euglycemia (p = 0.01; N = 6, 677 capillaries at baseline and 552 at clamp), while no significant SR variation was detected after performing a sham clamp in Experiment 1b (11.0 ± 1.6 cells/sec at baseline and 11.4 ± 3.7 cells/sec at sham clamp; N = 6, 837 capillaries at baseline and 724 at sham clamp). In Experiment 2 using the gas exchange chamber, SR significantly decreased at 12% O2 (p = 0.01, p &lt; 0.03) and significantly increased at 2% O2 (p = 0.01, p &lt; 0.04), compared to baseline 7% O2, under both baseline and euglycemic conditions respectively (N = 6, 313 capillaries at baseline and 195 at clamp). SR responses to oxygen oscillations during euglycemia were not different to those at baseline for each O2 concentration (p &gt; 0.9). SO2 significantly increased at 12% O2 and significantly decreased at 2% O2 under both baseline and euglycemic conditions (p &lt; 0.05).ConclusionsOur saturation measurements demonstrate the effectiveness of using a gas exchange device to manipulate local oxygen concentrations in the muscle. Our SR results suggest the increase in blood flow observed in response to insulin is eliminated if the tissue oxygen microenvironment is fixed at a given [O2].

Blood Flow Heterogeneity and Oxygenation in the Lung: Effect of the Hypoxic Pulmonary Vasoconstriction Response Curve

The ability of the lung to take up oxygen can be characterized by its effective diffusing capacity, which is determined by the transport characteristics of the alveolar‐capillary membrane as well as heterogeneity of pulmonary blood flow. At rest, the healthy lung has a high degree of tolerance for pulmonary flow heterogeneity, but under conditions of physiological stress such as exercise, oxygen uptake may be inadequate to satisfy tissue demand if flow is very heterogeneous. We previously used a mathematical model of pulmonary oxygen uptake to examine the ability of hypoxic pulmonary vasoconstriction (HPV) to mitigate flow heterogeneity. In the model, flow heterogeneity is characterized by the coefficient of variation (CV) of pulmonary capillary blood flow. Assuming an initial lognormal distribution of blood flow with a normal level of heterogeneity (CV = 1.66), we simulate flow regulation over a range of oxygen consumption from rest to maximal exercise by adjusting pulmonary flow resistance in each vessel in accordance with an HPV response curve obtained from previously published experimental data. The effect of HPV on vessel flow resistance is assumed to be characterized by a sigmoidal response dependent on the capillary oxygen tension, which is approximated as the mean of the venous and arterial values in each pulmonary capillary; its maximal sensitivity occurs at a stimulus oxygen tension of approximately 30 torr. The purpose of the present study was to determine whether altering the shape of the HPV response curve would result in an improvement in CV reduction. Altering the HPV by shifting the sigmoidal curve to the right by 10 or 20 torr worsened CV, extraction and total pulmonary vascular resistance (PVR). Similar detrimental results were obtained when the range of oxygen tensions over which HPV varied was expanded by a factor of two, increasing the oxygen tension at which the sensitivity of HPV to oxygen tension was maximal. On the other hand, shrinking the range of variation of the HPV curve by a factor of two neither improved nor significantly worsened the CV or extraction, and resulted in a PVR distribution similar to the case of the normal HPV curve. These results demonstrate that the observed shape of the HPV response tends to minimize heterogeneity of pulmonary flow under conditions of exercise.

Role of hemogram-derived ratios in predicting intensive care unit admission in COVID-19 patients: a multicenter study

PurposeAs hyperinflammation is recognized as a driver of severe COVID-19 disease, checking markers of inflammation is gaining more attention. Our study aimed to evaluate the utility of cost-effective hemogram-derived ratios in predicting intensive care unit (ICU) admission in COVID-19 patients. MethodsThis multicenter retrospective study included hospitalized COVID-19 patients from four dedicated COVID-19 hospitals in Sylhet, Bangladesh. Data on demographics, clinical characteristics, laboratory parameters and survival outcomes were analyzed. Logistic regression analysis was used to identify the significance of each hemogram-derived ratio in predicting ICU admission. ResultsOf 442 included patients, 98 (22.17%) required ICU admission. At the time of admission, patients requiring ICU had a higher neutrophil count and lower lymphocyte and platelet counts than patients not requiring ICU. Peripheral capillary oxygen saturation at admission was significantly lower in those who subsequently required ICU admission. Neutrophil-to-lymphocyte ratio, derived neutrophil-to-lymphocyte ratio, neutrophil-to-platelet ratio, and systemic immune-inflammation index were significant predictors of ICU admission. ConclusionHemogram-derived ratios can be an effective tool in facilitating the early categorization of at-risk patients, enabling timely measures to be taken early in the disease course.

Clinical Evaluation of Micro-Embolic Activity with Unexpected Predisposing Factors and Performance of Horizon AF PLUS during Cardiopulmonary Bypass.

Background: During Cardiopulmonary Bypass (CPB) gaseous micro-emboli (GMEs) decrease the quality of the blood flow and the capillary oxygen delivery, increasing the incidence of postoperative neurocognitive disorders (POCD) following cardiac surgery. In these circumstances, the use of an efficient device, could be crucial for the removal and reduction of micro-embolic activity. Methods: From February 2022 to March 2022, we prospectively collected data from 40 consecutive patients undergoing conventional and minimally invasive cardiac surgery that used the Horizon AF PLUS (Eurosets, Medolla, Italy). We collected, during the CPB’s time, the incidence of unexpected predisposing factors for micro-embolic activity reported in the literature with the GMEs count and their diameter through the GAMPT BCC 300 (Germany). Results: The group of patients without unexpected predisposing factors for micro-embolic activity (55%) reported a GME volume of 0.59 ± 0.1 (μL) in the arterial line (p-value 0.67). In both groups were no reported performance deficit during the procedures for oxygenation and CO2 removal. Conclusions: Our clinical analysis showed that Horizon AF PLUS is an effective and safe device without iatrogenic perioperative complications, for the reduction of micro embolic activity during CPBs procedures, with high efficiency in terms of oxygenating performance and thermal exchange.

Quantitative effects of head rotation angle on apnea hypopnea index in positional obstructive sleep apnea \u2013 a preliminary case series

ObjectivesQuantify the effects of head rotation and head incline on obstructive sleep apnea (OSA) severity.DesignSingle-arm, intervention study.SettingPulmonary specialty clinic.Case presentationTen adults diagnosed with positional OSA ranging from 32 to 64 years of age 6 females, 4 males reporting persistent daytime sleepiness and health issues with consistent use of CPAP.InterventionStandard polysomnography with a head angle sensor attached to the forehead and coaching to fall asleep with head at various rotation and incline angles and torso in supine and non-supine positions.MeasurementsOSA severity was scored according to American Academy of Sleep Medicine guidelines. Apnea hypopnea index (AHI) and peripheral capillary oxygen (SpO2) saturation were measured during each sleep epoch of unique head rotation, head incline, and torso position.ResultsTwo participants (1 with no apneas and 1 with central sleep apnea) were excluded. Among the remaining 8 participants, average reduction in peak AHI was 66% (range 18–88%) with head rotation ≤ 20° above the horizon compared with > 20° above the horizon. The average of peak AHI values with head rotation ≤ 20° was significantly lower than with head rotation > 20° (20.0 vs 45.3, P = 0.002). Minimum SpO2 was significantly higher for head rotation ≤ 20° compared with > 20° (mean: 90.6% vs 84.3%, P = 0.03). In the torso supine position, average peak AHI was significantly lower with head rotation ≤ 20° compared with > 20° (7.1 vs 52.1, P < 0.001). In the torso non-supine position, lower average peak AHI with head rotation ≤ 20° was not statistically significant (22.3 vs 38.4, P = 0.09).ConclusionThese results support further exploration of maintaining head position ≤ 20° above the horizon to minimize AHI and oxygen desaturation in OSA patients.Trial registrationApnea Hypopnea Index Severity Versus Head Position During Sleep.ClinicalTrials.gov Identifier: NCT04086407 September 11, 2019 Registered retrospectively.

Muscle oxygenation and time to task failure of submaximal holding and pulling isometric muscle actions and influence of intermittent voluntary muscle twitches

BackgroundIsometric muscle actions can be performed either by initiating the action, e.g., pulling on an immovable resistance (PIMA), or by reacting to an external load, e.g., holding a weight (HIMA). In the present study, it was mainly examined if these modalities could be differentiated by oxygenation variables as well as by time to task failure (TTF). Furthermore, it was analyzed if variables are changed by intermittent voluntary muscle twitches during weight holding (Twitch). It was assumed that twitches during a weight holding task change the character of the isometric muscle action from reacting (≙ HIMA) to acting (≙ PIMA).MethodsTwelve subjects (two drop outs) randomly performed two tasks (HIMA vs. PIMA or HIMA vs. Twitch, n = 5 each) with the elbow flexors at 60% of maximal torque maintained until muscle failure with each arm. Local capillary venous oxygen saturation (SvO2) and relative hemoglobin amount (rHb) were measured by light spectrometry.ResultsWithin subjects, no significant differences were found between tasks regarding the behavior of SvO2 and rHb, the slope and extent of deoxygenation (max. SvO2 decrease), SvO2 level at global rHb minimum, and time to SvO2 steady states. The TTF was significantly longer during Twitch and PIMA (incl. Twitch) compared to HIMA (p = 0.043 and 0.047, respectively). There was no substantial correlation between TTF and maximal deoxygenation independently of the task (r = − 0.13).ConclusionsHIMA and PIMA seem to have a similar microvascular oxygen and blood supply. The supply might be sufficient, which is expressed by homeostatic steady states of SvO2 in all trials and increases in rHb in most of the trials. Intermittent voluntary muscle twitches might not serve as a further support but extend the TTF. A changed neuromuscular control is discussed as possible explanation.

Novel biomarker-based score (SAD-60) for predicting mortality in patients with COVID-19 pneumonia: a multicenter retrospective cohort of 1013 patients.

Background: The aim was to explore a novel risk score to predict mortality in hospitalized patients with COVID-19 pneumonia. Methods: This was a retrospective, multicenter study. Results: A total of 1013 patients with COVID-19 were included. The mean age was 60.5 ± 14.4 years, and 581 (57.4%) patients were male. In-hospital death occurred in 124 (12.2%) patients. Multivariate analysis revealed peripheral capillary oxygen saturation (SpO2), albumin, D-dimer and age as independent predictors. The mortality score model was given the acronym SAD-60, representing SpO2, Albumin, D-dimer, age ≥60 years. The SAD-60 score (0.776) had the highest area under the curve compared with CURB-65 (0.753), NEWS2 (0.686) and qSOFA (0.628) scores. Conclusion: The SAD-60 score has a promising predictive capacity for mortality in hospitalized patients with COVID-19.

Interim Analysis of Impact of Adding Low Dose Pulmonary Radiotherapy to Moderate COVID-19 Pneumonia Patients: IMpaCt-RT Study.

BackgroundTreatment for coronavirus disease 2019 (COVID-19) pneumonia remains largely supportive till date and multiple clinical trials took place within the short span of time to evaluate the role of investigational therapies. The anti-inflammatory effect of low dose whole lung radiation in treating pneumonia has been documented earlier. This clinical trial analyzed the effect of low dose radiation therapy (LDRT) in a moderately affected COVID-19 pneumonia patient cohort and has evaluated its effect in stopping the conversion of moderate disease into severe disease.MethodsPatients with moderate COVID-19 pneumonia as characterized by the Ministry of Health and Family Welfare (MOHFW), Government of India, were randomized (1:1) to low dose whole lung radiation versus no radiation. All treatment of patients was concurrently being given as per institutional protocol. Patients were followed up with clinical and laboratory parameters monitored on Days 1, 3, 7, and 14. Computed tomography scan (CT scan) of thorax was performed on Days 1 and 7. Patients were evaluated for conversion of moderate into severe disease as per National Early Warning Score-2 (NEWS-2 score) as the primary end point. The secondary endpoints included changes in ratio between peripheral capillary oxygen saturation and fraction of inspired oxygen (SpO2/FiO2), biochemical markers, 25-point CT severity score, and radiation induced acute pulmonary toxicities.FindingsAt the interim analysis, there were seven patients in the radiation arm and six in the control. A whole lung LDRT improved the outcome of SpO2/FiO2 at Day 3; however it did not convert into a statistically significant improvement for the NEWS-2 score. The serum levels of LDH, CRP, Ferritin and D-dimer were significantly reduced on 14 days in the LDRT arm in comparison to the baseline value but were not significant between the two groups.InterpretationLDRT seems to have the potential to prevent moderate COVID-19 pneumonia from a deteriorating to severe category. However, further randomized clinical trial with an adequate number of such patients is warranted to establish the definitive role of LDRT in the management of COVID-19 pneumonia.FundingAn intramural research project bearing code: I-27/621, was sanctioned from the All India Institute of Medical Sciences, Patna, India.Clinical Trial RegistrationClinical Trials Registry-India (CTRI/2021/06/033912, 25th May 2021) ctri.nic.in/Clinicaltrials/login.php

Treatment with JianPiYiFei II granules for patients with moderate to very severe chronic obstructive pulmonary disease: A 52-week randomised, double-blinded, placebo-controlled, multicentre trial

BackgroundComplementary and alternative therapy is widely used to treat chronic obstructive pulmonary disease (COPD). A Chinese herbal medicine, JianPiYiFei (JPYF) II granules, have been shown to improve COPD patients’ quality of life, however long-term effectiveness has not been examined. PurposeTo investigate whether long-term treatment with JPYF II granules is effective and safe for patients with stable, moderate to very severe COPD. Study Design and MethodsA multicentre, randomised, double-blinded, placebo-controlled trial was conducted. Eligible participants from six hospitals were randomly assigned 1:1 to receive either JPYF II granules or placebo for 52 weeks. The primary outcome was the change in St. George's Respiratory Questionnaire (SGRQ) score during treatment. Secondary outcomes included the frequency of acute exacerbations during treatment, COPD Assessment Test (CAT), 6-minute walking test (6MWT), lung function, body mass index, airflow obstruction, dyspnoea, exercise capacity (BODE) index, and peripheral capillary oxygen saturation (SpO2) at the end of treatment. ResultsA total of 276 patients (138 in each group) were included in the analysis. JPYF II granules led to a significantly greater reduction in SGRQ score (-7.33 points, 95% CI -10.59 to -4.07; p < 0.0001) which reflects improved quality of life. JPYF II granules improved CAT (-3.49 points, 95% CI -5.12 to -1.86; p < 0.0001) and 6MWT (45.61 metres, 95% CI 20.26 to 70.95; p = 0.0005), compared with placebo. Acute exacerbations were less frequent with JPYF II granules than with placebo (0.87 vs. 1.34 events per patient; p = 0.0043). There were no significant differences between the groups in lung function, BODE index and SpO2. JPYF II granules were well tolerated and no significant adverse effects were noted. ConclusionsLong-term treatment with JPYF II granules is effective in moderate to very severe COPD, improving quality of life and exercise capacity, decreasing the risk of acute exacerbation, and relieving symptoms.

A Comparison of Oxygenation Efficacy between High-Flow Nasal Cannulas and Standard Facemasks during Elective Tracheal Intubation for Patients with Obesity: A Randomized Controlled Trial.

Obese patients are predisposed to rapid oxygen desaturation during tracheal intubation. We aimed to compare the risk of desaturation between high-flow nasal oxygenation (HFNO) and classical facemask oxygenation (FMO) during rapid sequence intubation for elective surgery in obese patients. Adults with a body mass index ≥30 kg·m−2 undergoing laparoscopic sleeve gastrectomy at a medical center were randomized into the HFNO group (n = 40) and FMO group (n = 40). In the HFNO group, patients used a high-flow nasal cannula to receive 30 to 50 L·min−1 flow of heated and humidified 100% oxygen. In the FMO group, patients received a fitting facemask with 15 L·min−1 flow of 100% oxygen. After 5-min preoxygenation, rapid sequence intubation was performed. The primary outcome was arterial desaturation during intubation, defined as a peripheral capillary oxygen saturation (SpO2) <92%. The risk of peri-intubation desaturation was significantly lower in the HFNO group compared to the FMO group; absolute risk reduction: 0.20 (95% confidence interval: 0.05–0.35, p = 0.0122); number needed to treat: 5. The lowest SpO2 during intubation was significantly increased by HFNO (median 99%, interquartile range: 97–100) compared to FMO (96, 92–100, p = 0.0150). HFNO achieved a higher partial pressure of arterial oxygen (PaO2) compared to FMO, with medians of 476 mmHg (interquartile range: 390–541) and 397 (351–456, p = 0.0010), respectively. There was no difference in patients’ comfort level between groups. Compared with standard FMO, HFNO with apneic oxygenation reduced arterial desaturation during tracheal intubation and enhanced PaO2 among patients with obesity.