Peripheral Blood Oxygen Saturation Research Articles

Pulse oximetry for the prediction of acute mountain sickness: A systematic review.

Acute mountain sickness (AMS) causes serious illness for many individuals ascending to high altitude (HA), although preventable with appropriate acclimatisation. AMS is a clinical diagnosis, with symptom severity evaluated using the Lake Louise Score (LLS). Reliable methods of predicting which individuals will develop AMS have not been developed. This systematic review evaluates whether a predictive relationship exists between oxygen saturation and subsequent development of AMS. PubMed, PubMed Central, MEDLINE, Semantic Scholar, Cochrane Library, University of Birmingham Library and clinicaltrials.gov databases were systematically searched from inception to 15 June 2023. Human studies involving collection of peripheral blood oxygen saturation ( ) from healthy lowlanders during ascent to HA that evaluated any relationship between and AMS severity were considered for eligibility. Risk of bias was assessed using a modified Newcastle-Ottawa Tool for cohort studies (PROPSPERO CRD42023423542). Seven of 980 total identified studies were ultimately included for data extraction. These studies evaluated and AMS (via LLS) in 1406 individuals during ascent to HA (3952-6300m). Risk of bias was 'low' for six and 'moderate' for one of the included studies. Ascent profiles and measurement methodology varied widely, as did the statistical methods for AMS prediction. Decreasing oxygen saturation measured with pulse oximetry during ascent shows a positive predictive relationship for individuals who develop AMS. Studies have high heterogeneity in ascent profile and oximetry measurement protocols. Further studies with homogeneous methodology are required to enable statistical analysis for more definitive evaluation of AMS predictability by pulse oximetry.

Pilot study of home-based monitoring for early prediction of acute exacerbations in patients with fibrosing interstitial lung diseases

This study aimed to assess the potential of home monitoring using a monitoring application for the early prediction of acute exacerbations (AEs) in patients with fibrosing interstitial lung diseases (F-ILDs) by tracking symptoms, peripheral blood oxygen saturation (SpO2), and heart rate (HR). Data on symptoms, SpO2, and HR before and after a 1-min sit-to-stand test (1STST) were collected using an online home monitoring application. Symptoms were recorded at least 3 times a week, including cough intensity and frequency (Cough Assessment Test scale (COAT) score), breathlessness grade (modified Medical Research Council (mMRC) score), and SpO2 and HR before and after 1STST. Eighty-five patients with stable F-ILDs were enrolled. We observed a significant increase in COAT and mMRC scores, alongside a significant decrease in SpO2 before and after 1STST, 2 weeks before the first recorded AE. Furthermore, a combination of variables-an increase in COAT (≥ 4) and mMRC(≥ 1) scores, a decrease in SpO2 at rest (≥ 5%), and a decrease in SpO2 after 1STST (≥ 4%)- proved the most effective in predicting AE onset in patients with F-ILDs at 2 weeks before the first recorded AE. Home telemonitoring of symptoms, SpO2 holds potential value for early AE detection in patients with F-ILDs.

Elevation and distraction of the Tibial periosteum in the management of chronic ischemic lower limb diseases.

This study investigates the effectiveness of tibia periosteum distraction (TPD) applied to the tibial periosteum, an innovative approach grounded in Ilizarov's tension-stress theory, for the treatment of ischemic diabetic foot and vasculitic foot conditions. A retrospective analysis was conducted on 33 patients (36 limbs) who underwent TPD between June 2019 and May 2022. The study comprised 21 males (23 limbs) and 12 females (13 limbs), aged 41 to 80 years (mean age: 63.4 years). Diabetic foot accounted for 27 cases, thromboangiitis obliterans for 2 cases, and arterial occlusive disease for 4 cases. The distribution of affected limbs included 15 left feet and 21 right feet. Periosteum traction commenced on the third postoperative day at a rate of approximately 0.75mm/day, adjusted biweekly. The traction device was removed after two weeks. Evaluation included capillary refill and wound healing assessment, along with pre- and postoperative analysis of foot skin temperature, ankle-brachial index (ABI), visual analogue scale (VAS) pain scores, and peripheral blood oxygen saturation. CT angiography (CTA) was utilized to assess vascular conditions in both lower limbs. All 33 patients were successfully followed up for a duration ranging from 4 to 24 weeks (mean: 11.03 weeks). VAS pain scores significantly decreased from preoperative (5.09 ± 1.70, range: 2-8) to postoperative two weeks (2.24 ± 0.90, range: 1-4) (t = 9.44, p < .001). Oxygen saturation levels increased from 83.88% ± 11.82% (range: 58%-97%) preoperatively to 91.36% ± 5.69% (range: 76%-98%) at two weeks postoperatively (t = -4.21, p < .001). Foot skin temperature also showed a significant increase (t = -3.98, p < .001). Capillary refill test at two weeks postoperatively demonstrated notable improvement. CTA revealed evident neovascularization in the operated limbs compared to preoperative conditions. Wound improvement was significant in all 33 patients within two months postoperatively. TPD emerges as a promising technique for chronic ischemic lower limb diseases, demonstrating favorable preliminary outcomes in wound healing promotion and amputation rate reduction. Nevertheless, large-scale randomized controlled trials are essential to further validate its efficacy.

Intranasal Atomized Dexmedetomidine in Combination with Intranasal Atomized Butorphanol for dressing change sedation and analgesia in adult burn patients: A Randomized Clinical Trial.

We aimed to evaluate the efficacy of the Intranasal Atomized Dexmedetomidine (IAD)+Intranasal Atomized Butorphanol (IAB) combination therapy on adult burn patients undergoing dressing changes. Herein, 46 adult burn patients were enrolled and randomly divided into two groups: Dexmedetomidine-Butorphanol (DB) and Saline-Butorphanol (SB), treated with atomized dexmedetomidine+butorphanol and saline +butorphanol, respectively. The primary outcomes were the Ramsay Sedation Scale (RSS) and the Visual Analog Scale (VAS) scores. The secondary outcomes were Mean Blood Pressure (MBP), Heart Rate (HR), Respiratory Rate (RR), peripheral blood oxygen saturation (SpO2), total butorphanol consumption, and Adverse Effects (AEs). The two groups were comparable in age, sex, weight, and Total Burn Surface Area (TBSA). During dressing changes, the DB group exhibited significantly lower RSS levels (P<0.05). Besides, the two groups showed no significant differences in VAS scores across all measurement time points. Notably, the DB group exhibited decreased MBP at the beginning of the operation (P<0.0001), 10min after (P<0.0001), and 20min after (P=0.0205). HR decreased significantly at the beginning (P=0.0005) and 10min after (P=0.0088) in the DB group. Furthermore, the two groups showed no significant differences in RR and SpO2 levels. Additionally, the rescue butorphanol dose was lower in the DB group (P<0.001). Finally, dizziness and nausea incidences were significantly lower in the DB group (P<0.05). In conclusion, besides its hemodynamic adverse reactions, the IAD+IAB combination therapy exerted a better sedation effect in adult burn patients than IAB treatment alone.

HALF DOSE THROMBOLYSIS IN INTERMEDIATE – HIGH RISK PULMONARY EMBOLISM WITH TRICUSPID VALVE MOBILE MASS: A BAIL OUT STRATEGY

Abstract A 82–year–old previously healthy male was referred to the emergency department complaining sudden onset dyspnea and witnessed syncope complicated by head trauma. Recurrent dizziness occurred previously. No history or drug consumption noted. On admission: heart rate 90 beats/min, blood pressure 110/60 mmHg, respiratory rate 25 breaths/min, oxygen saturation 87% in room air, normal body temperature. No lower extremities tenderness or swelling reported. Consistent with peripheral blood oxygen saturation levels, arterial blood gas analysis showed hypoxemia and respiratory alkalosis. Laboratory exams were significant for thrombocytopenia (89.000 cells/L), elevated cardiac troponin T levels (222 ng/L) and natriuretic peptide (NT pro–BNP 3944 pg/mL). Head CT excluded acute cerebral hemorrhage. At the electrocardiogram, signs of RV strain were present (biphasic T–waves in V1–V3 leads, S1–Q3–T3). Transthoracic echocardiography (TTE) showed dilated RV with hypokinetic free wall, “D–shaped” LV, “60/60” sign and a mobile filiform mass crossing the tricuspid valve plan in the right atrium (fig. 1). The patient did not present structural valvular abnormalities or endocarditis–related risk factors. CT pulmonary angiography detected a “saddle” PE and extensive thrombosis in inferior vena cava. After unfractioned heparin (UFH) bolus, the patient was transferred to our intensive care unit and balancing risks and benefits the chosen treatment option consisted in half dose systemic thrombolysis (50 mg rtPA in 60’’; 10 mg as loading dose in 2’). Because of potential harmful effects in thrombocytopenia and recent head trauma, UFH was temporarily withheld and started again after 1 hour. The day after, a beside TTE showed complete tricuspid thrombus resolution, a significant decrease in RV/LV ratio and systolic pulmonary artery pressure (fig. 2). Apart from small hematomas, no bleedings were reported. The patient was shifted to the ward on the next day and following course was uneventful. On day 4 a direct oral anticoagulant (Dabigatran 110 mg) was started. Abdominal and inferior limb–deep–venous ultrasound were both negative for pathological reports. A total body CT was scheduled to exclude silent malignancies at discharge. Take home message: in intermediate–high risk PE, half dose systemic fibrinolysis strategy is controversial since its potential benefit is counterbalanced by concerns about major bleedings, but increasing data suggest its efficacy with low risk profile.

The effects of acute normobaric hypoxia on standing balance while dual-tasking with and without visual input.

To investigate the influence of acute normobaric hypoxia on standing balance under single and dual-task conditions, both with and without visual input. 20 participants (7 female, 20-31years old) stood on a force plate for 16, 90-s trials across four balance conditions: single-task (quiet stance) or dual-task (auditory Stroop test), with eyes open or closed. Trials were divided into four oxygen conditions where the fraction of inspired oxygen (FIO2) was manipulated (normoxia: 0.21 and normobaric hypoxia: 0.16, 0.145 and 0.13 FIO2) to simulate altitudes of 1100, 3,400, 4300, and 5200m. Participants breathed each FIO2 for ~ 3min before testing, which lasted an additional 7-8min per oxygen condition. Cardiorespiratory measures included heart rate, peripheral blood oxygen saturation, and pressure of end tidal (PET) CO2 and O2. Center of pressure measures included total path length, 95% ellipse area, and anteroposterior and mediolateral velocity. Auditory Stroop test performance was measured as response accuracy and latency. Significant decreases in oxygen saturation and PETO2, and increased heart rate were observed between normoxia and normobaric hypoxia (P < 0.0001). Total path length was higher at 0.13 compared to 0.21 FIO2 for the eyes closed no Stoop test condition (P = 0.0197). No other significant differences were observed. These findings suggest that acute normobaric hypoxia has a minimal impact on standing balance and does not influence auditory Stroop test or dual-task performance. Further investigation with longer exposure is required to understand the impact and time course of normobaric hypoxia on standing balance.

The effect of Phytopaj ) Ferula assa-foetida L. oleo gum resin and tragacanth( in patients with COVID-19: A randomized clinical trial.

Exogenous hydrogen sulfide (H2S) has a positive effect on respiratory diseases. Oleo-gum of Ferula assa-foetida contains this compound. This study assessed the effects of Ferula assa-foetida L. oleo gum resin and tragacanth (Phytopaj) on patients with COVID-19. A randomized, single-blinded, controlled trial (RCT) phase 2 was conducted in Mashhad on hospitalized COVID-19 patients. In this RCT, 122 patients were randomly assigned to either receive a 14-day oral phytopaj plus ordinary treatment or ordinary treatment only. Changes in peripheral blood lymphocyte count (LC) and blood oxygen saturation (PO2) were the endpoints. Mean±SD of PO2 in Phytopaj comparison ordinary treatment before intervention was 91.86±4.62 and 91.41±9.18, after the intervention it was 93.22±4.26 and 91.91±5.92 mmHg; before intervention, mean±SD of peripheral blood lymphocyte count was 1015.90±500.55, and 1104.28±543.61, and after intervention, it was 1652.27±921.38 and 1326.12±719.28/μL respectively. Phyopaj is most useful in moderate stages of Covid19, and it is not recommended for elderly patients and patients with comorbidity until more insight is gained.

Reliability of continuous vital sign monitoring in post-operative patients employing consumer-grade fitness trackers: A randomised pilot trial.

Fitness trackers can provide continuous monitoring of vital signs and thus have the potential to become a complementary, mobile and effective tool for early detection of patient deterioration and post-operative complications. To evaluate potential implementations in acute care setting, we included 36 patients after moderate to major surgery in a recent randomised pilot trial to compare the performance of vital sign monitoring by three different fitness trackers (Apple Watch 7, Garmin Fenix 6pro and Withings ScanWatch) with established standard clinical monitors in post-anaesthesia care units and monitoring wards. During a cumulative period of 56 days, a total of 53,197 heart rate (HR) measurements, as well as 12,219 measurements of the peripheral blood oxygen saturation (SpO2) and 28,954 respiratory rate (RR) measurements were collected by fitness trackers. Under real-world conditions, HR monitoring was accurate and reliable across all benchmarked devices (r = [0.95;0.98], p < 0.001; Bias = [-0.74 bpm;-0.01 bpm]; MAPE∼2%). However, the performance of SpO2 (r = [0.21;0.68]; p < 0.001; Bias = [-0.46%;-2.29%]; root-mean-square error = [2.82%;4.1%]) monitoring was substantially inferior. RR measurements could not be obtained for two of the devices, therefore exclusively the accuracy of the Garmin tracker could be evaluated (r = 0.28, p < 0.001; Bias = -1.46/min). Moreover, the time resolution of the vital sign measurements highly depends on the tracking device, ranging from 0.7 to 117.94 data points per hour. According to the results of the present study, tracker devices are generally reliable and accurate for HR monitoring, whereas SpO2 and RR measurements should be interpreted carefully, considering the clinical context of the respective patients.

Blood Oxygen and Heart Rate Monitoring by A Flexible Hybrid Electronics Device Fabricated by Multilayer Screen‐Printing

AbstractPulse oximetry is widely used in medical settings and in everyday life for the estimation of peripheral blood oxygen saturation (SpO2). However, SpO2 response measured on the peripheral parts of the body (such as fingers and wrists) has a time lag compared to measuring on the forehead. In addition, current devices are centimeter‐thick, making seamless integration with the body difficult, and hindering continuous monitoring. Here a design, fabrication, and evaluation of a SpO2 and heart rate sensor based on flexible hybrid electronics (FHE) is presented. The marriage of flexible electronics with high‐performance commercially available integrated circuit (IC) chips makes advanced sensing, data processing, and wireless data transmission functionalities possible on a thin (1.6 mm) and flexible form that can be attached to various parts of the body. Differently from most devices using FHE, here a cost‐efficient and mass‐production compatible multilayer screen‐printing process for making the interconnection circuitry is described in detail, including topographic analysis. By optimizing the printing steps, interconnecting lines vertically traversing up to five printed layers over several tens of micrometers can be fabricated, increasing the spatial density. The device reliably detects hypoxemia, and when applied on the forehead, changes in SpO2 appear &gt;10 s earlier compared to a finger‐based medical‐grade device.

Combining blood glucose and SpO2/FiO2 ratio facilitates prediction of imminent ventilatory needs in emergency room COVID-19 patients

The increasing requirement of mechanical ventilation (MV) due to the novel coronavirus disease (COVID-19) is still a global threat. The aim of this study is to identify markers that can easily stratify the impending use of MV in the emergency room (ER). A total of 106 patients with COVID-19 requiring oxygen support were enrolled. Fifty-nine patients were provided MV 0.5 h (interquartile range: 0.3 to 1.4) post-admission. Clinical and laboratory data before intubation were collected. Using a multivariate logistic regression model, we identified four markers associated with the impending use of MV, including the ratio of peripheral blood oxygen saturation to fraction of inspired oxygen (SpO2/FiO2 ratio), alanine aminotransferase, blood glucose (BG), and lymphocyte counts. Among these markers, SpO2/FiO2 ratio and BG, which can be measured easily and immediately, showed higher accuracy (AUC: 0.88) than SpO2/FiO2 ratio alone (AUC: 0.84), despite no significant difference (DeLong test: P = 0.591). Moreover, even in patients without severe respiratory failure (SpO2/FiO2 ratio > 300), BG (> 138 mg/dL) was predictive of MV use. Measuring BG and SpO2/FiO2 ratio may be a simple and versatile new strategy to accurately identify ER patients with COVID-19 at high risk for the imminent need of MV.

Peripheral blood oxygen saturation (Spo2) value in the diagnosis of congenital heart disease in newborns at the Pediatric Center, Bach Mai Hospital

Peripheral blood oxygen saturation (Spo2) value in the diagnosis of congenital heart disease in newborns at the Pediatric Center, Bach Mai Hospital

Evaluation of Leading Smartwatches for the Detection of Hypoxemia: Comparison to Reference Oximeter.

Although smartwatches are not considered medical devices, experimental validation of their accuracy in detecting hypoxemia is necessary due to their potential use in monitoring conditions manifested by a prolonged decrease in peripheral blood oxygen saturation (SpO2), such as chronic obstructive pulmonary disease, sleep apnea syndrome, and COVID-19, or at high altitudes, e.g., during sport climbing, where the use of finger-sensor-based pulse oximeters may be limited. The aim of this study was to experimentally compare the accuracy of SpO2 measurement of popular smartwatches with a clinically used pulse oximeter according to the requirements of ISO 80601-2-61. Each of the 18 young and healthy participants underwent the experimental assessment three times in randomized order-wearing Apple Watch 8, Samsung Galaxy Watch 5, or Withings ScanWatch-resulting in 54 individual experimental assessments and complete datasets. The accuracy of the SpO2 measurements was compared to that of the Radical-7 (Masimo Corporation, Irvine, CA, USA) during short-term hypoxemia induced by consecutive inhalation of three prepared gas mixtures with reduced oxygen concentrations (14%, 12%, and 10%). All three smartwatch models met the maximum acceptable root-mean-square deviation (≤4%) from the reference measurement at both normal oxygen levels and induced desaturation with SpO2 less than 90%. Apple Watch 8 reached the highest reliability due to its lowest mean bias and root-mean-square deviation, highest Pearson correlation coefficient, and accuracy in detecting hypoxemia. Our findings support the use of smartwatches to reliably detect hypoxemia in situations where the use of standard finger pulse oximeters may be limited.

Experiences of Patients With Chronic Obstructive Pulmonary Disease Using the Apple Watch Series 6 Versus the Traditional Finger Pulse Oximeter for Home SpO2 Self-Monitoring: Qualitative Study Part 2

Background Amid the rise in mobile health, the Apple Watch now has the capability to measure peripheral blood oxygen saturation (SpO2). Although the company indicated that the Watch is not a medical device, evidence suggests that SpO2 measurements among patients with chronic obstructive pulmonary disease (COPD) are accurate in controlled settings. Yet, to our knowledge, the SpO2 function has not been validated for patients with COPD in naturalistic settings. Objective This qualitative study explored the experiences of patients with COPD using the Apple Watch Series 6 versus a traditional finger pulse oximeter for home SpO2 self-monitoring. Methods We conducted individual semistructured interviews with 8 female and 2 male participants with moderate to severe COPD, and transcripts were qualitatively analyzed. All received a watch to monitor their SpO2 for 5 months. Results Due to respiratory distress, the watch was unable to collect reliable SpO2 measurements, as it requires the patient to remain in a stable position. However, despite the physical limitations and lack of reliable SpO2 values, participants expressed a preference toward the watch. Moreover, participants’ health needs and their unique accessibility experiences influenced which device was more appropriate for self-monitoring purposes. Overall, all shared the perceived importance of prioritizing their physical COPD symptoms over device selection to manage their disease. Conclusions Differing results between participant preferences and smartwatch limitations warrant further investigation into the reliability and accuracy of the SpO2 function of the watch and the balance among self-management, medical judgment, and dependence on self-monitoring technology.

Impacts of Skin Color and Hypoxemia on Noninvasive Assessment of Peripheral Blood Oxygen Saturation: A Scoping Review.

Standard pulse oximeters estimate arterial blood saturation (SaO2) non-invasively by emitting and detecting light of a specific wavelength through a cutaneous vascular bed, such as a digit or the ear lobe. The quantity measured at these peripheral sites is designated as oxygen saturation (SpO2). Most reliable pulse oximeters are calibrated from measurements of healthy volunteers using some form of oxygen desaturation method. As the degree of inducible hypoxemia is limited, the calibration below achievable desaturation levels is usually extrapolated, leading to potential measurement error at low SaO2 values, especially in highly pigmented skin. Such skin color-related errors (SCRE) are the topic of this scoping review. Specifically, this study aimed to identify the combined impact of skin color and reduced SaO2 on the non-invasive assessment of SpO2 and report the consequences of potential inaccuracies. Three databases were searched (Cumulated Index to Nursing and Allied Health Literature (CINAHL), PubMed, and Web of Science) for peer-reviewed prospective and retrospective studies published in English between 2000 and 2022 involving human patients with hypoxemia that included a measure of skin color (Fitzpatrick scale or race/ethnicity). Ten studies met the criteria and were included in the final review. Eight of these studies reported statistically significant higher pulse oximeter readingsin darker-skinned patients with hypoxia compared to their arterial blood gas measurements. Occult hypoxia was more prevalent in Black and Hispanic patients than in White patients. Minority patients overall (Black, Asian, and American Indian) were more likely to have a SaO2 < 88% that was not detected by pulse oximetry (occult hypoxemia) during hospitalization. With greater levels of hypoxemia, the differences between SpO2 and SaO2 were greater. If SaO2 was < 90%, then SpO2 was overestimated in all ethnicities but worse in minorities. In conclusion, the bias found in pulse oximeter readings in the skin of color broadly impacts patients with hypoxemia. The failure of SpO2 measuring devices to detect occult hypoxemia can delay the delivery of life-saving treatment to critically ill patients requiring respiratory rehabilitation and supplemental oxygen therapy. This may lead to adverse health outcomes, increased in-hospital mortality, and complications such as organ dysfunction. An improvement in pulse oximeter detection mechanisms that would include all skin pigmentations is therefore much desired to optimize individual healthcare status and minimize disparities in treatment.

The Effects of the Myobrace® System on Peripheral Blood Oxygen Saturation (SpO2) in Patients with Mixed Dentition with Oral Dysfunction.

Myobrace® is an orthodontic device that has the purpose of correcting oral dysfunctions, thus predisposing the physiological growth of the jaws, aligning teeth, and optimizing face development. This device is usually associated with Myobrace® Activities to reach this target. Considering the lack of studies in the literature about peripheral blood oxygen saturation (SpO2) and the use of preformed oral devices, the aim of this study is to quantify the change in blood oxygen saturation (SpO2) in patients treated with the Myobrace® System in mixed dentition. In this study, 23 children (11 females and 12 males) were involved, who were affected by different oral dysfunctions and were treated with a Myobrace®. Blood oxygen saturation measurements were taken at baseline and after every four months for a year. The SpO2 measurements were taken in the rest position and with a closed mouth for a total of 12 min-6 min with and 6 min without the Myobrace® oral device. All data points were anonymized and recorded on an Excel spreadsheet. A statistical analysis was carried out. Therapy with a Myobrace® in patients with mixed dentition resulted in a statistically significant increase in oxygen saturation. In particular, in patients with a closed mouth, a statistically significant increase in oxygen saturation was observed, bringing it from 97.66% to 99.00%, while in the rest position, the increase was from 98.03% to 99.07%. The use of Myobrace® devices in patients with mixed dentition could lead to a significant improvement in blood oxygen saturation.

Remote Blood Oxygen Estimation From Videos Using Neural Networks.

Peripheral blood oxygen saturation (SpO 2) is an essential indicator of respiratory functionality and received increasing attention during the COVID-19 pandemic. Clinical findings show that COVID-19 patients can have significantly low SpO 2 before any obvious symptoms. Measuring an individual's SpO 2 without having to come into contact with the person can lower the risk of cross contamination and blood circulation problems. The prevalence of smartphones has motivated researchers to investigate methods for monitoring SpO 2 using smartphone cameras. Most prior schemes involving smartphones are contact-based: They require using a fingertip to cover the phone's camera and the nearby light source to capture reemitted light from the illuminated tissue. In this paper, we propose the first convolutional neural network based noncontact SpO 2 estimation scheme using smartphone cameras. The scheme analyzes the videos of an individual's hand for physiological sensing, which is convenient and comfortable for users and can protect their privacy and allow for keeping face masks on. We design explainable neural network architectures inspired by the optophysiological models for SpO 2 measurement and demonstrate the explainability by visualizing the weights for channel combination. Our proposed models outperform the state-of-the-art model that is designed for contact-based SpO 2 measurement, showing the potential of the proposed method to contribute to public health. We also analyze the impact of skin type and the side of a hand on SpO 2 estimation performance.

PRE-DISCHARGE SYSTOLIC BLOOD PRESSURE IN HOSPITALIZED COVID-19 PATIENTS IS AN INDEPENDENT PREDICTOR OF IMROVEMENT IN 6-MINUTE WALK TEST DURING 1-MONTH FOLLOW-UP

Objective: To study the relation of hypertensive status and systolic blood pressure (SBP) pre-discharge values to the dynamics of functional re-conditioning as assessed by 6-minute walk distance during the 1-month follow-up after hospitalization for COVID-19. Design and method: 6-minute walk distance (6MWD) was assessed pre-discharge in 176 patients hospitalized for COVID-19 (40% hypertensive, 47% male, mean age 53,2 ± 13,5 years) using the 20 m walkway and an extended protocol that included monitoring of peripheral pulse and capillary blood oxygen saturation (SpO2) every 30 seconds via bluetooth-connected pulse oximeter. The repeated evaluation was performed after 1 month of follow-up. Results: Hypertensive participants were characterised by older age (57,8±11,8 vs 50,7±13,9, p &lt; 0,001), higher weight and body mass index (31,7±5,3 vs 27,4±4,4 kg/m2, p &lt; 0,001). As a result, 6MWD in them was shorter (378±57 vs 418±75 m, p = 0,001) but no difference in reached percent of predicted distance (6MWD%) was detected (63,0±8,5 vs 63,2±11,1 %, p = 0,939). The described relation persisted at 1 month, with no difference in absolute (72±43 vs 68±43 m, p = 0,324) and percentage gain of 6MWD (12,8±6,6 vs 11,2±7,5 %, p = 0,266) between groups. Multiple regression analysis has allowed to build the model that accounted for 94% of variability in the 6MWD% gain between visits (85% for dedicated hypertensive cohort model). After adjustment for age, sex, height, weight, Remdesivir treatment, minimal SpO2 levels during acute COVID-19, changes of SpO2 and pulse rate throughout the 6MWT, SBP remained a potent independent predictor of 6MWD% gain, with 10 mmHg higher values at baseline evaluation being associated with 21,5% lesser 6MWD% gain in hypertensive subjects and 8,2% lesser – in normotensives. Conclusions: Hypertensive status did not have an impact on 6MWD% in pre-discharge COVID-19 patients. Moderate-to-high quality multiple regression models have demonstrated an independent role of SBP, demographic and anthropometric data, changes of SpO2 and pulse rate throughout the 6MWT in prediction of 6MWD% gain during 1 month after discharge, both in hypertensive and normotensive patients.

Comparison of mathematically arterialised venous blood gas sampling with arterial, capillary, and venous sampling in adult patients with hypercapnic respiratory failure: a single-centre longitudinal cohort study

BackgroundAccurate arterial blood gas (ABG) analysis is essential in the management of patients with hypercapnic respiratory failure, but repeated sampling requires technical expertise and is painful. Missed sampling is common...

Effect of different levels of acute hypoxia on subsequent oral glucose tolerance in males with overweight: A balanced cross-over pilot feasibility study.

Previous research has shown that ≤60 min hypoxic exposure improves subsequent glycaemic control, but the optimal level of hypoxia is unknown and data are lacking from individuals with overweight. We undertook a cross-over pilot feasibility study investigating the effect of 60-min prior resting exposure to different inspired oxygen fractions (CON FI O2 =0.209; HIGH FI O2 =0.155; VHIGH FI O2 =0.125) on glycaemic control, insulin sensitivity, and oxidative stress during a subsequent oral glucose tolerance test (OGTT) in males with overweight (mean (SD) BMI=27.6 (1.3) kg/m2 ; n=12). Feasibility was defined by exceeding predefined withdrawal criteria for peripheral blood oxygen saturation (SpO2 ), partial pressure of end-tidal oxygen or carbon dioxide and acute mountain sickness (AMS), and dyspnoea symptomology. Hypoxia reduced SpO2 in a stepwise manner (CON=97(1)%; HIGH=91(1)%; VHIGH=81(3)%, p < 0.001), but did not affect peak plasma glucose concentration (CON=7.5(1.8) mmol∙L-1 ; HIGH=7.7(1.1) mmol∙L-1 ; VHIGH=7.7(1.1) mmol∙L-1 ; p=0.777; η2 =0.013), plasma glucose area under the curve, insulin sensitivity, or metabolic clearance rate of glucose (p > 0.05). We observed no between-conditions differences in oxidative stress (p > 0.05), but dyspnoea and AMS symptoms increased in VHIGH (p < 0.05), with one participant meeting the withdrawal criteria. Acute HIGH or VHIGH exposure prior to an OGTT does not influence glucose homeostasis in males with overweight, but VHIGH is associated with adverse symptomology and reduced feasibility.

Monitoring Perfusion Index in Patients Presenting to the Emergency Department Due to Drug Use

(1) Background: The perfusion index (PI) represents the ratio between pulsatile blood flow and non-pulsatile blood flow in the peripheral tissue. (2) We aimed to investigate the blood pressure perfusion of tissues and organs in ethnobotanical, synthetic cannabinoid and cannabis derivative consumers through the value of perfusion index. (3) Results: The patients enrolled were divided into two groups: group A, which included all patients who presented in the ED within the first three hours after consumption, and group B, which included those patients who presented more than three hours and up to 12 h after drug consumption. The average values of the PI in the case of group A/group B were 1.51 ± 1.07/4.55 ± 3.66. Statistically significant correlations in both groups were recorded between the drug intake ED admission, respiratory rate, peripheral blood oxygen saturation and tissue perfusion index (p < 0.001). The average value of the PI measured in group A was significantly lower compared to that measured in patients in group B. Therefore, we concluded that the perfusion of peripheral organs and tissues was lower in the first 3 h after drug administration. (4) Conclusions: PI plays an important role in the early detection of impaired organ perfusion and in monitoring tissue hypoxia. A decreased PI value may be an early indication of decreased perfusion organ damage.