Peripheral Blood Oxygen Saturation Research Articles

Intravenous Infusion of Exosomes Derived from Human Adipose Tissue-Derived Stem Cells Promotes Angiogenesis and Muscle Regeneration: An Observational Study in a Murine Acute Limb Ischemia Model.

Recent studies have demonstrated that adipose tissue-derived stem cell (ADSC) transplantation could promote neoangiogenesis in various ischemic diseases. However, as whole cells, ADSCs have some disadvantages, such as shipping and storage issues, high costs, and controversies related to the fates of grafted cells in the recipients. Therefore, this study aimed to investigate the effects of intravenously infused exosomes purified from human ADSCs on ischemic disease in a murine hindlimb ischemia model. ADSCs were cultured in exosome-free medium for 48h before the conditioned medium was collected for exosome isolation by ultracentrifugation. The murine ischemic hindlimb models were created by cutting and burning the hindlimb arteries. Exosomes were intravenously infused into murine models (ADSC-Exo group), with phosphate-buffered saline (PBS) used as a placebo (PBS group). Treatment efficacy was determined using a murine mobility assay (frequency of pedaling in water per 10s), peripheral blood oxygen saturation (SpO2 index), and the recovery of vascular circulation by trypan blue staining. The formation of blood vessels was shown by X-ray. Expression levels of genes related to angiogenesis and muscle tissue repair were quantified by quantitative reverse-transcription polymerase chain reaction. Finally, H&E staining was used to determine the histological structure of muscle in the treatment and placebo groups. The rates of acute limb ischemia in the PBS and ADSC-Exo injection groups were 66% (9/16 mice) and 43% (6/14 mice), respectively. The mobility of the limbs 28days after surgery was significantly different between the ADSC-Exo treatment group (41±1 times/10s) and the PBS group (24±1 times/10s; n=3; p<0.05). Peripheral blood oxygen saturation 21days after treatment was 83.83%±2.02% in the PBS group and 83%±1.73% in the ADSC-Exo treatment group, and the difference was not statistically significant (n=3, p>0.05). On day 7 after treatment, the time required to stain the toes after trypan blue injection was 20.67±12.5s and 85±7.09s in the ADSC-Exo and PBS groups, respectively (n=3, p<0.05). On day 3 after the operation, the expression of genes promoting angiogenesis and muscle remodeling, such as Flk1, Vwf, Ang1, Tgfb1, Myod, and Myf5, was increased 4-8 times in the ADSC-Exo group compared with the PBS group. No mice in either group died during the experimental period. These results revealed that intravenous infusion of human ADSC-derived exosomes is a safe and effective method to treat ischemic disease, especially hindlimb ischemia, by promoting angiogenesis and muscle regeneration.

Effects of Ultrasound-Guided Supraclavicular Block Using Bupivacaine-Dexmedetomidine or Bupivacaine Alone in Hemodynamics of Patients Undergoing Upper Limb Orthopedic Surgery

The aim of this study was to evaluate the effect of bupivacaine with dexmedetomidine in comparison with bupivacaine during supraclavicular block with ultrasound guide on the hemodynamics of patients undergoing upper limb orthopedic surgery. Eighty patients (40 patients in each group) who were candidates for upper limb orthopedic surgery randomly received 30 ml of bupivacaine alone (group 1) or 30 ml of bupivacaine with 20 μg of dexmedetomidine (group 2). The supraclavicular nerve block was performed using an ultrasound guide. Patients' hemodynamic data (including mean arterial blood pressure, heart rate per minute, respiration rate per minute, and peripheral blood oxygen saturation), the onset of action, and duration of sensory-motor block were compared between the two groups. The mean arterial blood pressure during surgery in group 2 was lower than in group 1, but the differences were not statistically significant. The onset of sensory and motor block in group 2 was significantly shorter than in group 1 (P=0.0001). The duration of sensory and motor block in group 2 was significantly longer than in group 1 (P=0.0001). During this study, none of the patients had hemodynamic disturbance or surgical complications. The addition of dexmedetomidine to bupivacaine during the supraclavicular block, in addition to hemodynamic stability of the patient during surgery, increases the duration of sensory and motor block.

Efficacy of two doses of dexmedetomidine on attenuating cardiovascular response and safety of respiratory tract to extubation.

Extubation can be associated with an adverse hemodynamic or respiratory response, which may be serious in cardiovascular written or in the elderly. The present study was conducted with the aim of investigating the effect of two different doses of dexmedetomidine in the prevention of extubation complications. This randomized clinical trial was conducted in Isfahan in 2020-2021 on 174 patients undergoing elective surgery. Patients were randomly divided into 3 groups receiving dexmedetomidine 1 μg/kg (D1), dexmedetomidine 0.5 μg/kg (D2), and normal saline (S). Hemodynamic variables include heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and peripheral blood oxygen saturation (Spo2) was measured and recorded before removing the endotracheal tube and at 1, 3, 5 and 10 minutes after extubation. Also, airway responses to extubation such as cough, hoarseness, and laryngospasm were investigated. SBP, MAP, and HR in the D1 group were significantly lower than in other groups. In the D2 group, these measurements were lower than the control group at 3, 5, and 10 minutes after extubation (P<0.05 for all). In placebo group, SBP, MAP, and HR increased significantly after extubation (P=0.01). In group D1, cough (P=0.007) and its intensity (P=0.013), nausea and vomiting (P=0.04) and chills (P=0.001) were less than in other groups. In the D1 group, attenuation of autonomic response to extubation was more than other groups and side effects were less than D2 group, and in both groups, these side effects were less than the saline group.

Comparative study of the effect of two different doses of intravenous labetalol on the cardiovascular response to endotracheal extubation.

Providing a stable hemodynamic in extubation is important. We aimed to compare the effect of two different doses of intravenous labetalol on the cardiovascular response to endotracheal extubation. This double-blind randomized trial was performed in 2019-2020 in Isfahan on 72 patients under general anesthesia. Patients using Random Allocation software were divided into three groups and received 0.1 mg/ kg or 0.2 mg/kg labetalol and normal saline intravenously 10 min before extubation. Hemodynamic variables including heart rate (HR), Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and peripheral blood oxygen saturation(SPO2) was measured for each patient before induction of anesthesia and 1, 3, 5 and 10 minutes after extubation. SBP changes were significantly different between the three groups at 1, 3, 5 minutes after extubation (P=0.036, P=0.009, P=0.005 respectively) unlike the other two groups, patients who received 0.2 mg/kg labetalol did not have an increase in DBP after extubation (P>0.05). DBP was significantly different between the three groups one minute after extubation (P=0.03). At minutes 1 and 3 following extubation, there was a significant difference in the MAP between the three groups. (P=0.029 and P=0.012 respectively). There was no significant difference between the three groups regarding heart rate (P>0.05). Tracheal extubation is usually associated with an increase in hemodynamic variables. Both doses of labetalol attenuate the hemodynamic response accompanying tracheal extubation. But labetalol 0.2 mg/kg in reducing hemodynamic response to extubation acted more effectively than labetalol 0.1mg/kg.

Effectiveness and safety of pulse oximetry in remote patient monitoring of patients with COVID-19

Abstract Context A surge of COVID cases globally is often portrayed as “very likely”, which overwhelms health systems and challenges their capacities. A mitigation strategy is seen by remotely monitoring COVID patients in out-of-hospital settings to determine the risk of deterioration. Description of the problem We need an indicator to enable remote monitoring of COVID patients at home that can be measured by a handy tool; pulse oximetry which measures peripheral blood oxygen saturation (SpO2). Evidence shows that SpO2 is a reliable indicator of deterioration among COVID patients. The UK initiated a national programme (COVID Oximetry @ Home (CO@H)) to assess the theory. The concept can be potentially applied in other countries in various settings. As part of CO@H, we conducted a systematic review of the evidence on the safety and effectiveness of pulse oximetry in remote monitoring of COVID patients. Results Our review confirms the safety and potential effectiveness of pulse oximetry in remote home monitoring among COVID patients. We identified 13 research projects involving 2,908 participants that assessed the proposed strategy. Evidence shows the need to monitor at-rest and post-exertional SpO2. At-rest SpO2 of ≤ 92% or a decrease of 5% or more in post-exertional SpO2 should indicate care escalation. The recommended method for measuring at-rest SpO2 is after 5-10 min of rest, and assessing post-exertional SpO2 is after conducting a 1-min sit-to-stand test. We could not find explicit evidence on the impact on health service use compared with other models of care. Lessons Remote monitoring of COVID patients could alleviate the pressure on health systems and save hospital resources. Monitoring SpO2 by pulse oximetry can be widely applied, including in resource-limited settings, as the tool is affordable, reliable, and easy to use. Key messages • Adopting relevant health technologies in remote patient monitoring is critical to combat the pandemic. • Pulse oximetry is an affordable, easy to use and widely available tool to monitor patients with COVID-19 at home.

Differential methylation in EGLN1 associates with blood oxygen saturation and plasma protein levels in high-altitude pulmonary edema

BackgroundHigh-altitude (HA, 2500 m) hypoxic exposure evokes a multitude of physiological processes. The hypoxia-sensing genes though influence transcriptional output in disease susceptibility; the exact regulatory mechanisms remain undetermined in high-altitude pulmonary edema (HAPE). Here, we investigated the differential DNA methylation distribution in the two genes encoding the oxygen-sensing HIF-prolyl hydroxylases, prolyl hydroxylase domain protein 2 (PHD2) and factor inhibiting HIF-1α and the consequent contributions to the HAPE pathophysiology.MethodsDeep sequencing of the sodium bisulfite converted DNA segments of the two genes, Egl nine homolog 1 (EGLN1) and Hypoxia Inducible Factor 1 Subunit Alpha Inhibitor (HIF1AN), was conducted to analyze the differential methylation distribution in three study groups, namely HAPE-patients (HAPE-p), HAPE-free sojourners (HAPE-f) and healthy HA natives (HLs). HAPE-p and HAPE-f were permanent residents of low altitude (< 200 m) of North India who traveled to Leh (3500 m), India, and were recruited through Sonam Norboo Memorial (SNM) hospital, Leh. HLs were permanent residents of altitudes at and above 3500 m. In addition to the high resolution, bisulfite converted DNA sequencing, gene expression of EGLN1 and HIF1AN and their plasma protein levels were estimated.ResultsA significantly lower methylation distribution of CpG sites was observed in EGLN1 and higher in HIF1AN (P < 0.01) in HAPE-p compared to the two control groups, HAPE-f and HLs. Of note, differential methylation distribution of a few CpG sites, 231,556,748, 231,556,804, 231,556,881, 231,557,317 and 231,557,329, in EGLN1 were significantly associated with the risk of HAPE (OR = 4.79–10.29; P = 0.048–004). Overall, the methylation percentage in EGLN1 correlated with upregulated plasma PHD2 levels (R = − 0.36, P = 0.002) and decreased peripheral blood oxygen saturation (SpO2) levels (R = 0.34, P = 0.004). We also identified a few regulatory SNPs in the DNA methylation region of EGLN1 covering chr1:231,556,683–231,558,443 suggestive of the functional role of differential methylation distribution of these CpG sites in the regulation of the genes and consequently in the HIF-1α signaling.ConclusionsSignificantly lower methylation distribution in EGLN1 and the consequent physiological influences annotated its functional epigenetic relevance in the HAPE pathophysiology.

Effect Of Moderate- And Vigorous-intensity Aerobic And Anaerobic Exercise On A Woman With Post-covid-19 Syndrome

Individuals with post-COVID-19 syndrome (long COVID) are subject to a variety of persistent symptoms including sporadic bouts of dyspnea. Both aerobic and anaerobic exercise modalities are effective treatments for the management of other chronic respiratory diseases, but exercise tolerance or benefits in long COVID remains unclear. PURPOSE: The purpose of this case study was to determine if exercise of various intensities and modalities triggered dyspneic episodes in a person with long COVID. METHODS: A woman (44 yrs; 73 kg; BMI 24.4 kg·m-2; resting peripheral blood oxygen saturation (SpO2) 98%) who was infected with COVID-19 in November 2020 followed by persistent and unpredictable bouts of significant dyspnea was tested 8 months post-infection. All tests were performed on the same day and included a graded exercise treadmill test (GXT) at habitual walking speed (1.34 m·sec-1) with an increasing grade of 2% per minute, a 6-min treadmill walking tests at 60% and 80% peak heart rate (HR), one-repetition maximum (1RM) seated leg press, and 8-repetition leg press sets at 50%, 60%, 70%, and 80% 1RM. The order of testing (post-test rest period) were: GXT (10 min); 60% walking (10 min); 80% walking (10 min); 1RM determination (3 min); 50% 1RM, 60% 1RM, 70% 1RM, 80% 1RM (3 min between sets). SpO2 was captured via fingertip pulse oximeter, dyspnea was assessed by the Modified Borg Dyspnea Scale (Borg), and HR was captured using a chest-strap HR monitor. RESULTS: During all aerobic tests the participant maintained normal oxygen saturation (SpO2 range: 95-98%, greatest desaturation during 60% walking at minutes 2 & 6) and did not reach 5 (severe dyspnea) on the Borg (range: 0.5-4, highest rating at peak GXT). Similar results were seen during anaerobic testing (SpO2 range 98-99%, greatest desaturation at 50% & 60% 1RM sets; Borg range 0.5-3, highest rating post-80% 1RM set). CONCLUSION: Acute bouts of moderate- and vigorous-intensity aerobic or anaerobic exercise did not trigger severe dyspnea in a participant with long COVID prone to episodes of breathlessness. These results suggest that research using moderate or vigorous aerobic or strength training may be feasible for individuals with long COVID to determine whether training adaptation can be safely induced, as seen in other cohorts with chronic respiratory disease.

Post‐fatigue ability to activate muscle is compromised across a wide range of torques during acute hypoxic exposure

The purpose of this study was to assess how severe acute hypoxia alters the neural mechanisms of muscle activation across a wide range of torque output in a fatigued muscle. Torque and electromyography responses to transcranial and motor nerve stimulation were collected from 10 participants (27 years ± 5 years, 1 female) following repeated performance of a sustained maximal voluntary contraction that reduced torque to 60% of the pre‐fatigue peak torque. Contractions were performed after 2 h of hypoxic exposure and during a sham intervention. For hypoxia, peripheral blood oxygen saturation was titrated to 80% over a 15‐min period and remained at 80% for 2 h. Maximal voluntary torque, electromyography root mean square, voluntary activation and corticospinal excitability (motor evoked potential area) and inhibition (silent period duration) were then assessed at 100%, 90%, 80%, 70%, 50% and 25% of the target force corresponding to the fatigued maximal voluntary contraction. No hypoxia‐related effects were identified for voluntary activation elicited during motor nerve stimulation. However, during measurements elicited at the level of the motor cortex, voluntary activation was reduced at each torque output considered (P = .002, η p 2 = .829). Hypoxia did not impact the correlative linear relationship between cortical voluntary activation and contraction intensity or the correlative curvilinear relationship between motor nerve voluntary activation and contraction intensity. No other hypoxia‐related effects were identified for other neuromuscular variables. Acute severe hypoxia significantly impairs the ability of the motor cortex to voluntarily activate fatigued muscle across a wide range of torque output.

The Effect of Acupuncture Therapy on Blood Oxygen Saturation in Patients with Blood Pressure Disorders and Coughs in Elderly Health Post, Surakarta

Background: One way to detect functional disorders of respiration, heart, blood vessels, and muscle oxidative mechanisms is to check blood gas saturation using a pulse oximeter, especially during the COVID-19 pandemic. Acupuncture is one of the management of health problems at the promotive level, preventing functional disorders of the respiratory system, cardiovascular system, and oxidative muscle rehabilitative which is used to improve health status, especially those who experience changes in blood gas saturation due to chronic cough, hypertension, hypotension, and muscle fatigue. The aim of the study was to determine the effect of acupuncture therapy on peripheral blood oxygen saturation (peripheral SpO2) in patients with a history of respiratory system disorders and blood pressure disorders, especially old age at the Surakarta Health Post.Subjects dan Method: The form of the research was pre-experimental (quasi-experimental), using two groups of pre-test and post-test purposive samples totaling 20 people. Dependent variable Oxygen saturation. The independent variable was acupuncture therapy. Data were analyzed using Wilcoxon's test.Results: Peripheral blood oxygen saturation values were higher in the intervention group before the intervention (Mean= 83.00; SD= 11.59) than after the intervention (Mean= 82.00; SD= 7.53) and not statistically significant (p= 0.294).Conclusion: Acupuncture therapy reduces blood gas saturation values in patients with blood pressure and cough disorders. Keywords: acupuncture therapy, peripheral blood gas saturation, pulse oximeter, history of cough, blood pressure disorders. Correspondence:Listina Ade Widya Ningtyas. Poltekkes Kemenkes Surakarta. Jl. Letjend Sutoyo Mojosongo, Surakarta, Central Java. Email: ade.widya23@gmail.com. Mobile: 085647300048

Prediction of serious outcomes based on continuous vital sign monitoring of high-risk patients

Continuous monitoring of high-risk patients and early prediction of severe outcomes is crucial to prevent avoidable deaths. Current clinical monitoring is primarily based on intermittent observation of vital signs and the early warning scores (EWS). The drawback is lack of time series dynamics and correlations among vital signs. This study presents an approach to real-time outcome prediction based on machine learning from continuous recording of vital signs. Systolic blood pressure, diastolic blood pressure, heart rate, pulse rate, respiration rate and peripheral blood oxygen saturation were continuously acquired by wearable devices from 292 post-operative high-risk patients. The outcomes from serious complications were evaluated based on review of patients’ medical record. The descriptive statistics of vital signs and patient demographic information were used as features. Four machine learning models K-Nearest-Neighbors (KNN), Decision Trees (DT), Random Forest (RF), and Boosted Ensemble (BE) were trained and tested. In static evaluation, all four models had comparable prediction performance to that of the state of the art. In dynamic evaluation, the models trained from the static evaluation were tested with continuous data. RF and BE obtained the lower false positive rate (FPR) of 0.073 and 0.055 on no-outcome patients respectively. The four models KNN, DT, RF and BE had area under receiver operating characteristic curve (AUROC) of 0.62, 0.64, 0.65 and 0.64 respectively on outcome patients. RF was found to be optimal model with lower FPR on no-outcome patients and a higher AUROC on outcome patients. These findings are encouraging and indicate that additional investigations must focus on validating performance in a clinical setting before deployment of the real-time outcome prediction.

Oxygen Desaturation Is Associated With Fibrocyte Activation via Epidermal Growth Factor Receptor/Hypoxia-Inducible Factor-1α Axis in Chronic Obstructive Pulmonary Disease.

Fibrocytes are bloodborne mesenchymal progenitors which accumulate and differentiate at the disease site. We investigated whether hypoxemia activates fibrocytes, accelerating airflow limitation and exercise intolerance in chronic obstructive pulmonary disease (COPD) patients. Flow cytometry was used to determine collagen I+/CD45+ fibrocytes and α-smooth muscle actin+ differentiating fibrocytes within peripheral blood and cultured cells, as well as the expression of CXC chemokine receptor 4 (CXCR4), epidermal growth factor receptor (EGFR), connective tissue growth factor (CTGF) and hypoxia-inducible factor (HIF)-1α. Fibrocytes in lung specimens were identified by confocal microscopy. Compared to non-desaturators, COPD desaturators (peripheral blood oxygen saturation ≤88% during exercise) had greater number of fibrocytes in peripheral blood and lung specimens, paralleled with faster yearly lung function decline and a 6-minute walk distance. Fibrocytes from desaturators expressed more EGFR, CXCR4, CTGF, and HIF-1α, with a higher capacity of proliferation and myofibroblastic differentiation. Hypoxia (5% oxygen) increased the expression of EGFR, CXCR4, CTGF, and HIF-1α, the number and differentiation in fibrocytes. These effects were attenuated by EGFR inhibitor gefitinib, HIF-1α gene silencing, and anti-CTGF antibody. These data elucidate that hypoxemia triggers fibrocyte activation through the EGFR/HIF-1α axis, aggravating airflow obstruction in COPD.

Prospective cohort study of referred Malawian children and their survival by hypoxaemia and hypoglycaemia status.

ObjectiveTo investigate survival in children referred from primary care in Malawi, with a focus on hypoglycaemia and hypoxaemia progression.MethodsThe study involved a prospective cohort of children aged 12 years or under referred from primary health-care facilities in Mchinji district, Malawi in 2019 and 2020. Peripheral blood oxygen saturation (SpO2) and blood glucose were measured at recruitment and on arrival at a subsequent health-care facility (i.e. four hospitals and 14 primary health-care facilities). Children were followed up 2 weeks after discharge or their last clinical visit. The primary study outcome was the case fatality ratio at 2 weeks. Associations between SpO2 and blood glucose levels and death were evaluated using Cox proportional hazards models and the treatment effect of hospitalization was assessed using propensity score matching.FindingsOf 826 children recruited, 784 (94.9%) completed follow-up. At presentation, hypoxaemia was moderate (SpO2: 90–93%) in 13.1% (108/826) and severe (SpO2: < 90%) in 8.6% (71/826) and hypoglycaemia was moderate (blood glucose: 2.5–4.0 mmol/L) in 9.0% (74/826) and severe (blood glucose: < 2.5 mmol/L) in 2.3% (19/826). The case fatality ratio was 3.7% (29/784) overall but 26.3% (5/19) in severely hypoglycaemic children and 12.7% (9/71) in severely hypoxaemic children. Neither moderate hypoglycaemia nor moderate hypoxaemia was associated with mortality.ConclusionPresumptive pre-referral glucose treatment and better management of hypoglycaemia could reduce the high case fatality ratio observed in children with severe hypoglycaemia. The morbidity and mortality burden of severe hypoxaemia was high; ways of improving hypoxaemia identification and management are needed.

Equity-Driven Sensing System for Measuring Skin Tone-Calibrated Peripheral Blood Oxygen Saturation (OptoBeat): Development, Design, and Evaluation Study.

Many commodity pulse oximeters are insufficiently calibrated for patients with darker skin. We demonstrate a quantitative measurement of this disparity in peripheral blood oxygen saturation (SpO2) with a controlled experiment. To mitigate this, we present OptoBeat, an ultra-low-cost smartphone-based optical sensing system that captures SpO2 and heart rate while calibrating for differences in skin tone. Our sensing system can be constructed from commodity components and 3D-printed clips for approximately US $1. In our experiments, we demonstrate the efficacy of the OptoBeat system, which can measure SpO2 within 1% of the ground truth in levels as low as 75%. The objective of this work is to test the following hypotheses and implement an ultra-low-cost smartphone adapter to measure SpO2: skin tone has a significant effect on pulse oximeter measurements (hypothesis 1), images of skin tone can be used to calibrate pulse oximeter error (hypothesis 2), and SpO2 can be measured with a smartphone camera using the screen as a light source (hypothesis 3). Synthetic skin with the same optical properties as human skin was used in ex vivo experiments. A skin tone scale was placed in images for calibration and ground truth. To achieve a wide range of SpO2 for measurement, we reoxygenated sheep blood and pumped it through synthetic arteries. A custom optical system was connected from the smartphone screen (flashing red and blue) to the analyte and into the phone's camera for measurement. The 3 skin tones were accurately classified according to the Fitzpatrick scale as types 2, 3, and 5. Classification was performed using the Euclidean distance between the measured red, green, and blue values. Traditional pulse oximeter measurements (n=2000) showed significant differences between skin tones in both alternating current and direct current measurements using ANOVA (direct current: F2,5997=3.1170 × 105, P<.01; alternating current: F2,5997=8.07 × 106, P<.01). Continuous SpO2 measurements (n=400; 10-second samples, 67 minutes total) from 95% to 75% were captured using OptoBeat in an ex vivo experiment. The accuracy was measured to be within 1% of the ground truth via quadratic support vector machine regression and 10-fold cross-validation (R2=0.97, root mean square error=0.7, mean square error=0.49, and mean absolute error=0.5). In the human-participant proof-of-concept experiment (N=3; samples=3 × N, duration=20-30 seconds per sample), SpO2 measurements were accurate to within 0.5% of the ground truth, and pulse rate measurements were accurate to within 1.7% of the ground truth. In this work, we demonstrate that skin tone has a significant effect on SpO2 measurements and the design and evaluation of OptoBeat. The ultra-low-cost OptoBeat system enables smartphones to classify skin tone for calibration, reliably measure SpO2 as low as 75%, and normalize to avoid skin tone-based bias.

Surgical Masks Affect the Peripheral Oxygen Saturation and Respiratory Rate of Anesthesiologists.

BackgroundSurgical masks (SMs) protect medical staff and reduce surgical site infections. Extended SM use may reduce oxygen concentrations in circulation, causing hypoxia, headache, and fatigue. However, no research has examined the effects of wearing SMs on oxygenation and physical discomfort of anesthesiologists.MethodsAn electronic questionnaire was established and administered through WeChat, and a cross-sectional survey was conducted to determine SM use duration and related discomfort of operating room medical staff. Then, operating room anesthesiologists were enrolled in a single-arm study. Peripheral blood oxygen saturation (SpO2), heart rate, and respiratory rate were determined at different times before and after SM use. Shortness of breath, dizziness, and headache were subjectively assessed based on the visual analog scale (VAS) scores.ResultsIn total, 485 operating room medical staff completed the electronic questionnaire; 70.5% of them did not change SMs until after work, and 63.9% wore SMs continuously for more than 4 h. The proportion of anesthesiologists was the highest. After wearing masks for 4 h, the shortness of breath, fatigue, and dizziness/headache rates were 42.1, 34.6, and 30.9%, respectively. Compared with other medical staff, the proportion of subjective discomfort of anesthesiologists increased significantly with prolonged SM use from 1 to 4 h. Thirty-five anesthesiologists completed the study. There was no difference in anesthesiologist SpO2, heart rate, or respiratory rate within 2 h of wearing SMs. After more than 2 h, the variation appears to be statistically rather than clinically significant—SpO2 decreased (98.0 [1.0] vs. 97.0 [1.0], p < 0.05), respiratory rate increased (16.0 [3.0] vs. 17.0 [2.0], p < 0.01), and heart rate remained unchanged. As mask use duration increased, the VAS scores of shortness of breath, dizziness, and headache gradually increased.ConclusionIn healthy anesthesiologists, wearing SMs for more than 2 h can significantly decrease SpO2 and increase respiratory rates without affecting heart rates.

The effect of the comfort care model on distress, pain, and hemodynamic parameters in infants after congenital heart defect surgery

Backgroundand purpose: Surgery is essential for many infants with heart defects. Pain, mental distress, and hemodynamic instability are among the main complications of these surgeries. This study investigates the effect of the Comfort Theory on pain, distress, and hemodynamic parameters in infants following heart surgery. MethodsIn this clinical trial, 60 infants aged 28 days to two years were selected by convenience sampling and divided into two groups by block randomization. The nursing intervention was implemented based on Kolcaba's Theory of Comfort, and data including demographic details, comfort behaviors, and hemodynamic parameters were collected. ResultsSignificant differences were observed between the two groups in the mean scores of distress, pain, breathing, and heart rate (P < 0.05). No significant differences were observed in the mean scores of body temperature, blood pressure, peripheral blood oxygen saturation, serum lactate level, arterial blood pressure, mean arterial pressure, and central venous pressure 24, 48, and 72 h after the intervention (P > 0.05). ConclusionInterventions based on the Comfort Theory reduce children's distress and relieve their pain as the major comfort needs of this group and can be recommended to nurses working in pediatric surgery wards as an effective evidence-based method. Implication for practiceNurses should consider pediatric patients' comfort after cardiac surgery then comfort theory can be used as a strategy for reducing children's pain, distress and considerate comfort for children. Based on this theory Psychospiritual and sociocultural dimensions should be considered in designing pediatric care. In the results using nursing theories enhances comprehensive children care.

DIAGNOSIS OF PULMONARY EMBOLISM IN THE EMERGENCY DEPARTMENT.

SUMMARYThe aim of this study was to determine the association of clinical presentation, the Wells scoring system and D-dimer values with MSCT pulmonary angiography. A case control study was conducted in the Emergency Department of the Clinical Hospital Sveti Duh throughout 2019. Patients with a referral diagnosis of a pulmonary embolism were included in the study. Patients were divided into two groups. The first group consisted of patients diagnosed with pulmonary embolism by MSCT pulmonary angiography or postmortem, and the second group consisted of patients excluded from pulmonary embolisms. For the Wells score, D-dimers, troponin, respiratory rate and peripheral blood oxygen saturation, statistically significant differences were found between groups of patients with confirmed or excluded pulmonary embolism (p <0.001). For heart rate, chest pain, syncope, and hemoptysis, no statistically significant differences were found between these two groups of patients. Deep venous thrombosis of the lower extremities was found by ultrasound in > 70% of patients with massive a pulmonary embolism. Pulmonary embolism was confirmed in all patients for whom a high risk was calculated according to the Wells score. In conclusion, a low degree of clinical probability (according to the Wells score), along with a normal concentration of D-dimer, are a sure strategy in excluding pulmonary embolism.

Commercial smartwatch with pulse oximeter detects short-time hypoxemia as well as standard medical-grade device: Validation study.

ObjectiveWe investigated how a commercially available smartwatch that measures peripheral blood oxygen saturation (SpO2) can detect hypoxemia compared to a medical-grade pulse oximeter.MethodsWe recruited 24 healthy participants. Each participant wore a smartwatch (Apple Watch Series 6) on the left wrist and a pulse oximeter sensor (Masimo Radical-7) on the left middle finger. The participants breathed via a breathing circuit with a three-way non-rebreathing valve in three phases. First, in the 2-minute initial stabilization phase, the participants inhaled the ambient air. Then in the 5-minute desaturation phase, the participants breathed the oxygen-reduced gas mixture (12% O2), which temporarily reduced their blood oxygen saturation. In the final stabilization phase, the participants inhaled the ambient air again until SpO2 returned to normal values. Measurements of SpO2 were taken from the smartwatch and the pulse oximeter simultaneously in 30-s intervals.ResultsThere were 642 individual pairs of SpO2 measurements. The bias in SpO2 between the smartwatch and the oximeter was 0.0% for all the data points. The bias for SpO2 less than 90% was 1.2%. The differences in individual measurements between the smartwatch and oximeter within 6% SpO2 can be expected for SpO2 readings 90%–100% and up to 8% for SpO2 readings less than 90%.ConclusionsApple Watch Series 6 can reliably detect states of reduced blood oxygen saturation with SpO2 below 90% when compared to a medical-grade pulse oximeter. The technology used in this smartwatch is sufficiently advanced for the indicative measurement of SpO2 outside the clinic.Trial RegistrationClinicalTrials.gov NCT04780724

Comparison of Chest-to-Back Skin-to-Skin Contact and Chest-to-Chest Skin-to-Skin Contact on the Risk of Oxygen Desaturation and Change in Heart Rate in Low Birth Weight and/or Premature Babies: A Randomized Controlled Clinical Trial.

Chest-to-chest (CC) skin-to-skin contact (SSC) is a widely used method of SSC to prevent low birth weight (LBW) and/or premature babies with the risk of hypothermia. However, very recently, a study has also shown that the chest-to-back (CB) SSC is also useful for such a purpose. It is also evident that CC SSC enhances the cardiorespiratory performance of LBW and/or premature babies from the risk of cold stress. However, whether babies kept in CB SSC have the risk of clinically relevant decreases of oxygen saturation or critical changes of the baby heart rate comparing the two SSC methods has been studied hardly. Thus, we assessed the risk of oxygen desaturation and changes in babies' heart rate among LBW and/or premature babies kept in CB SSC compared to the standard. In this study, we enrolled 46 LBW and/or premature babies born between 32 and 37 completed weeks of gestation. We used a parallel-group randomized controlled clinical trial. Peripheral arterial blood oxygen saturation (SpO2) and heart rate (HR) were measured using an OxiMaxN-600X Pulse Oximeter. We transformed these measurements into stability of the cardiorespiratory system in premature infant (SCRIP) scores. We applied a generalized estimating equation model to analyze the data. No statistically significant difference was observed between babies kept in CB SSC compared to babies kept in CC SSC in either blood oxygen saturation or heart rate (P > 0.05). Thus, the CB SSC can be used as one possible way to care for LBW and preterm babies in the kangaroo mother care. We suggest more studies before scaling up the approach in routine care.

Severe acute hypoxia impairs recovery of voluntary muscle activation after sustained submaximal elbow flexion.

The purpose of this study was to determine how severe acute hypoxia alters neural mechanisms during, and following, a sustained fatiguing contraction. Fifteen participants (25±3.2years, six female) were exposed to a sham condition and a hypoxia condition where they performed a 10min elbow flexor contraction at 20% of maximal torque. For hypoxia, peripheral blood oxygen saturation ( ) was titrated to 80% over a 15min period and maintained for 2h. Maximal voluntary contraction torque, EMG root mean square, voluntary activation, rating of perceived muscle fatigue, and corticospinal excitability (motor-evoked potential) and inhibition (silent period duration) were then assessed before, during and for 6min after the fatiguing contraction. No hypoxia-related effects were identified for neuromuscular variables during the fatigue task. However, for recovery, voluntary activation assessed by motor point stimulation of biceps brachii was lower for hypoxia than sham at 4min (sham: 89%±7%; hypoxia: 80%±12%; P=0.023) and 6min (sham: 90%±7%; hypoxia: 78%±11%; P=0.040). Similarly, voluntary activation (P=0.01) and motor-evoked potential area (P=0.002) in response to transcranial magnetic stimulation of the motor cortex were 10% and 11% lower during recovery for hypoxia compared to sham, respectively. Although an of 80% did not affect neural activity during the fatiguing task, motor cortical output and corticospinal excitability were reduced during recovery in the hypoxic environment. This was probably due to hypoxia-related mechanisms involving supraspinal motor circuits. KEY POINTS: Acute hypoxia has been shown to impair voluntary activation of muscle and alter the excitability of the corticospinal motor pathway during exercise. However, little is known about how hypoxia alters the recovery of the motor system after performing fatiguing exercise. Here we assessed hypoxia-related responses of motor pathways both during active contractions and during recovery from active contractions, with transcranial magnetic stimulation and motor point stimulation of the biceps brachii. Fatiguing exercise caused reductions in voluntary activation, which was exacerbated during recovery from a 10min sustained elbow flexion in a hypoxic environment. These results suggest that reductions in blood oxygen concentration impair the ability of motor pathways in the CNS to recover from fatiguing exercise, which is probably due to hypoxia-induced mechanisms that reduce output from the motor cortex.

Early Immune Profile Assessment By Flow Cytometry Predicts Severe COVID-19 Pneumonia

▪Background and ObjectiveThe rapid spread of the COVID -19 pandemic and the high variability of the course of the disease make it essential to search for early predictors of outcome. The objective of our study is to predict severe SARS COV2 pneumonia using early cytometric profilesMaterial and MethodsProspective and observational study of adults with confirmed COVID-19 infection admitted on Emergency Department (ED). We collected epidemiological, clinical and laboratory data of every patient until they were discharged or died. Multiparametric flow cytometry (FC) analysis of T-lymphocytes (CD4, CD8, CD4 activated, CD8 activated, naïve (Tn), central-memory (Tcm), effector-memory (Tem), effector (Te) and Th17 subsets), B-lymphocytes (naïve, memory, transitional subsets, and assessment of clonality), NK cells, plasmablasts, p-DCs (plasmacytoid dendritic cells), m-DCs (myeloid dendritic cells), basophils, and monocytes (MO1, MO2, MO3, slan+ MO3) was performed on whole peripheral blood collected on EDTA, before immunosuppressive therapy was started. We designed a 7-tube 8-color experimental panel. Cell surface staining of 2 × 106 cells was performed and at least 500 000 total events were acquired for the assessment of plasmablasts, p-DCs, m-DCs, basophils, and the monocyte subsets; for the study of B, T and NK-lymphocyte populations we acquired at least 100 000 total events (FACS Canto II; BD Biosciences). Severity was assessed on the basis of World Health Organization´s (WHO) international 10 level ordinal scale (WHOs) and also according to 4 respiratory status, based on SpO2(peripheral blood oxygen saturation)/FIO2 (fraction of inspired oxygen) ratio (SpFi). SpFi group 1 >452, SpFi2 2: 315-452; SpFi 3 236-315, SpFi 4: <236 (respiratory distress)Results53 patients were included: epidemiological and clinical data available on table 1. 23 patients (43.39%) arrived to SpFi4 status. WHOs >6 (WHO 6:oxygen by non invasive ventilation or high flow) was achieved by 20 patients (37.7%)Good prognosis (meaning SpFi1 as the worse respiratory status in the follow -up) was associated to cytometric profiles: there was a significant increase in CD3, p-DCs, m-DCs, basophils, monocytes, Tcm, % of lymphocytes and CD3/CD19 ratio whereas there was a significant reduction in CD19, % of neutrophils and % Neutrophils/% lymphocyte ratio. In the SpFi4 group, there was a significant reduction of CD3, p-DCs, m-DCs, plasmablasts and CD3/NK ratio. In patients starting in SpFi group 1-2 in the ED but progressing to SpFi 3-4 during the follow up (27 patients), there was a statistically significant relation with Tn, Te and Tn/Te ratio (Tn/Te ratio <0.717: OR 13.5 (p 0.002, [95% CI 2.552-71.403). Initial SpFi1 patients that evolved to SpFi 3-4 during follow up (10 patients), presented a Tn/Te ratio < 0.717 with an OR 11.556 (p =0.005, [95% CI 2.059-64.853]).Plasmablasts < 0.075 and CD3/NK <5.71, were identified as independent risk factors for SpFI4 during follow up. After multivariable analysis, both variables kept their significance: CD3/NK (OR 11,247, p=0.005) and plasmablasts (OR 12,524 , p=0.004). About prediction of WHOs >6, multivariable analysis showed CD3/NK <5.71 (OR 22,240 [95%CI 2,340-211,342] p= 0.007) and plasmablasts<0.075 (OR 28.635 [95% CI 3,187-257,301] p=0.003).A score (0,1,2) comprising both risk factors, was significantly predictive of SpFI4, regardless of the initial respiratory status, age or days from symptoms onset. In our cohort, only 1/15 (6.7%) patients with 0 points (neither plasmablasts nor CD3/NK score), arrived to SpFi4. However, 10/11 (90.9%) patients with 2 points, reached to SpFi4 respiratory status (C-index = 0.837) Same score was applied to predict WHOs > 6: 90.9% with 2 points progressed to WHO>6 and 0/15 patients with 0 points reached the same goal (C-index = 0.872)An incidental finding of 4 indolent B-lymphoproliferative disorders (2CLL-like MBLs and 2non -CLL-like MBL), was found, and they were associated with older age and progression to death.ConclusionsFlow cytometry on whole peripheral blood samples of SARS-COV2 pneumonia patients, collected before corticosteroid or immunosuppressive therapy, could identify cytometric patterns associated to prognosis. Plasmablasts, mDCs and pDCs levels as well as CD3/NK ratio, are associated to a worse respiratory status, while Tn/Te ratio could detect non-severe patients who will require high-flow oxygen devices during follow up. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.