SaO2 Values Research Articles

Evaluation of Oxygen Saturation Levels Using a Custom-modified Finger Pulse Oximeter for Assessment of Pulp Vitality in Various Clinical Situations in Pediatric Dental Practice: An In Vivo Study.

A major drawback of traditional pulp testing procedures is that they depend on neural responses rather than vascular circulation. Hence, this study aimed to develop a custom-modified dental sensor using a finger pulse oximeter (PO) that is applicable to any type of tooth so as to test its ability and accuracy in evaluating the oxygen saturation (SaO2) values of teeth at different developmental stages as a measure of pulp vitality. A customized finger PO was employed to determine the systemic and pulp SaO2 levels in 300 children. A total of 600 teeth (primary and permanent) were divided into group I (100 primary molars), group II (200 permanent molars), group III (200 permanent incisors), and 100 endodontically treated (primary and permanent) teeth were included in group IV. The mean SaO2 values thus obtained in various groups were compared. Intragroup comparison of mean SaO2% of the patient's finger (systemic), test teeth, and control teeth showed significant differences (p ≤ 0.001). Intergroup comparisons also revealed significant differences in most of the groups. The modified PO probe can be applied to any type of tooth. It was found to be accurate and sensitive enough to detect changes in SaO2 levels in various clinical situations irrespective of developmental stage. It proved to be a direct method of evaluation of pulp vitality by objective means. Patil A, Garg N, Pathivada L, et al. Evaluation of Oxygen Saturation Levels Using a Custom-modified Finger Pulse Oximeter for Assessment of Pulp Vitality in Various Clinical Situations in Pediatric Dental Practice: An In Vivo Study. Int J Clin Pediatr Dent 2024;17(S-1):S30-S36.

Pulmonary hypertension in newly diagnosed obstructive sleep apnea-chronic obstructive pulmonary disease overlap syndrome patients attending a tertiary care centre-a cross-sectional analysis.

Overlap syndrome is the association of obstructive sleep apnea (OSA) with chronic obstructive pulmonary disorder and with other chronic respiratory diseases. Patients with overlap syndrome have a worse prognosis compared with chronic obstructive pulmonary disorder or OSA alone. Additionally, patients with combined chronic obstructive pulmonary disorder and OSA are more likely to develop pulmonary hypertension and right heart failure much earlier than those without overlap. To assess the occurrence of pulmonary hypertension (PH) in newly diagnosed OSA-chronic obstructive pulmonary disorder overlap syndrome patients attending a tertiary care centre. This cross-sectional study was conducted at Department of Pulmonary Medicine, Government Medical College, Kozhikode, Kerala, South India, among patients with OSA above 40years of age who were proactively evaluated to pick out those with undiagnosed overlap. A period of 6months after getting ethical clearance from June 2018 was selected as the study period. Among patients with symptoms suggestive of OSA above 40years of age who gave the informed consent were enrolled after screening with Standard Sleep questionnaires (Berlin questionnaire, STOP BANG and Epworth Sleepiness Scale). Enrolled patients underwent routine spirometry and sleep study using the standard Level 1 overnight polysomnography (Level1 OPSG). Patients were classified in to two groups as OSA patients (group I), having an apnea hypopnea index (AHI) > 5/hr alone and the second group as those OSA patients (group II), with an obstructive spirometry pattern who were the overlap group. Arterial blood gas analysis (a sample of radial arterial blood was drawn with the patient awake and supine, and was analyzed for pH, PaCO2 and PaO2) and echocardiography (ECHO) of the two groups were compared as a non-invasive method to assess pulmonary artery hypertension and results were analyzed in a systematic manner. Among the 84 patients enrolled, 16.7% had overlap syndrome and the rest had OSA alone. Statistically significant higher mean weight and BMI for those with overlap syndrome compared to the OSA group were observed. Mean FVC (forced vital capacity), FEV1 (forced expiratory volume 1s), and FEV1/FVC were lower in those with overlap syndrome compared to OSA group. The mean values of ABG parameters revealed higher PaCO2 and lower PaO2 among the group with overlap syndrome which were statistically significant. However, there was no significant difference in resting room air SaO2 value between the two groups. The mean values of sleep duration and efficiency were significantly lower in those with overlap syndrome with a p value < 0.001. The mean value of arousal and REM (rapid eye movement) sleep percentage were significantly higher among those with overlap syndrome (p < 0.001). Mean value of NREM (non-rapid eye movement) sleep percentage was lower among the group with overlap syndrome compared with the OSA group, and this difference was statistically significant. The mean AHI value of the overlap syndrome group was 39.79 ± 7.54 and this was significantly higher than the OSA group (p < 0.004). Among the 14 patients who had ECHO evidence of pulmonary hypertension, 9 (64.3%) belonged to the overlap group which shows that they are a highly vulnerable group for developing pulmonary hypertension (PH) and requires early detection and more rigorous treatment. This study confirms that OSA patients with modest daytime level of hypoxemia and mild-moderate chronic airflow limitation have a high prevalence of PH. Chronic airway obstruction may be asymptomatic in some subjects and this stresses the necessity of pulmonary function test in OSA.

Racial effects on masimo pulse oximetry: impact of low perfusion index

Purpose: Evaluate the SpO2-SaO2 difference between Black and White volunteer subjects having a low perfusion index (Pi) compared to those having a normal Pi. Methods: The Pi data were abstracted from electronic files collected on 7183 paired SpO2-SaO2 samples (3201 Black and 3982 White) from a recently reported desaturation study of 75 subjects (39 Black and 36 White) where SaO2 values were sequentially decreased from 100 to 70%. The Pi values from that dataset were divided into two groups (Pi ≤ 1 or Pi > 1) for analysis. A Pi value ≤ 1 was considered “low perfusion” and a Pi value > 1 was considered “normal perfusion”. Statistical calculations included values of bias (mean difference of SpO2-SaO2), precision (standard deviation of the difference), and accuracy (root-mean-square error [ARMS]). During conditions of low perfusion (Pi ≤ 1, range [0.1 to 1]), overall bias and precision were + 0.48% ± 1.59%, while bias and precision were + 0.19 ± 1.53%, and + 0.91 ± 1.57%, for Black and White subjects, respectively. Results: During normal perfusion (Pi > 1, range [1 to 12]), overall bias and precision were + 0.18% ± 1.34%, while bias and precision were -0.26 ± 1.37%, and − 0.12 ± 1.31%, for Black and White subjects, respectively. ARMS was 1.37% in all subjects with normal perfusion and 1.64% in all subjects with low perfusion. Conclusion: Masimo SET® pulse oximeters with RD SET® sensors are accurate for individuals of both Black and White races when Pi is normal, as well as during conditions when Pi is low. The ARMS for all conditions studied is well within FDA standards. This study was conducted in healthy volunteers during well-controlled laboratory desaturations, and results could vary under certain challenging clinical conditions.

Changes the level of differentiating growth factor - GDF 15 in patients with sleep apnea syndrome after aPAP-therapy: pilot study

Comparative assessment of the level of differentiating growth factor 15 (GDF 15 ) against the background of a 6-month course of respiratory support in the mode of automatic positive pressure in the airways therapy (aPAP therapy) in patients with obstructive sleep apnea syndrome (OSA). 59 men participated in the study, the average age was 51.9±2.4 years. The main group (MG1) consisted of 30 patients with a verified diagnosis of moderate OSA. 29 men of comparable age and body weight made up the control group (CG) without an objectively confirmed diagnosis of OSA. After the stage of introduction into the study, the type of respiratory support with individual pressure settings was selected for patients with MG1. After 6 months of aPAP therapy with high compliance (at least 85%), the same patients who made up MG2 after treatment underwent repeated polysomnography (PSG) and the GDF 15 content was evaluated. Methods: questionnaire, examination, polysomnography, enzyme immunoassay of blood serum to determine the content of GDF 15. A 6-month course of aPAP therapy with a high degree of compliance significantly improved the sleep structure and breathing pattern: the representation of NREM 3 increased from 79.2±15.6 to 102.6±21.6 minutes and the REM phase from 56.9± 13.6 to 115.6±26.8. Episodes of apnea were eliminated - apnea-hypopnea index decreased from 21.1 [17.3; 39.1] to 2.5 [1.8; 4.6] and the average values of SaO2 increased from 85.9% to 91.5%. At the same time, a statistically significant excess of GDF 15 was revealed in MG1 - 20.4 [14.16; 31.71] and MG2 - 17.2 [13.63; 24.44]) in comparison with CG - 13.65 [10.7; 17.09]. Despite the lack of statistical significance, a change in the level of GDF 15 was revealed in the form of a decrease in its concentration after a 6-month course of aPAP therapy. A 6-month course of aPAP therapy made it possible to eliminate intermittent nocturnal hypoxia and improve sleep structure in patients with OSA, as well as reduce the content of GDF 15 protein in blood serum in patients with OSA. However, the tendency to decrease the content of this protein, despite the lack of statistical reliability, confirms the effectiveness of OSA therapy and the possibility of preventing early and pathological aging from the standpoint of somnology and molecular biogerontology.

Effect of Obesity on the Respiratory Parameters in Children with Obstructive Sleep Apnea Syndrome.

The study analyzes 56 Caucasian children and adolescents aged 11 ± 2.79 years with a BMI > 5th percentiles and a PSQ value ≥ 0.33. Children were divided into Obesity Group (OG) with BMI ≥ 95th and Control Group (CG) with 5th < BMI > 95th percentile. All selected children underwent PG. Respiratory parameters AHI (Apnea-Hypopnea Index), SaO2 (Saturation of Oxygen), ODI (Oxygen Desaturation Index), and Nadir (the lowest value of SaO2 registered during PG) were extracted from the PG. AHI was used to divide the severity of OSAS into four levels: snoring (AHI ≤ 1), mild (AHI > 1 and ≤5), moderate (AHI > 5 and <10), and severe (AHI ≥ 10). The comparison analysis between the OG and CG showed a statistical significance only for ODI (p = 0.02). A statistically significant correlation between BMI and AHI (r = 0.02), SaO2 (r = 0.01), and Nadir O2 (r = 0.02) was found. There was no strong correlation between obesity and OSAS, but a positive association was found between BMI and AHI severity.

Results of long-term riociguat therapy, including a switching strategy from sildenafil, in patients with pulmonary hypertension of various genesis

Aim: to study the influence of riociguat on the functional and hemodynamic status, remodeling of the right heart, as well as the safety of therapy in both previously untreated patients with idiopathic pulmonary arterial hypertension (IPAH) and inoperable chronic thromboembolic PH (CTEPH), and those not achieved treatment goals with sildenafil therapy and switching to riociguat.Materials and methods. A total of 161 pts with precapillary PH were included in the study; 137 pts completed the three-year observation period. Of 55 IPAH pts riociguat was started after diagnosis verification in 39 pts (subgroup 1); 16 pts previously taking sildenafil who did not achieve treatment goals comprised subgroup 2 of switching to riociguat. Of 82 inoperable CTEPH pts riociguat was started in 45 naїve pts; a switching strategy riociguat was implemented in 37 pts after 24-hour withdrawal of sildenafil. The dose titration of riociguat was started from 1 mg TID according to the standard algorithm up to 7.5 mg/day. By month 36 92.4% and 94.8% of pts with IPAH and CTEPH, respectively, received 7.5 mg/day. At baseline, at month 12, 24 and 36 all pts underwent a 6-minute walking test (6MWT) with the assessment of the dyspnea index according to the Borg scale and SpO2, echocardiography (Echo), right heart catheterization (RHC), and the safety profile was assessed.Results. At baseline, the proportion of pts with FC III-IV in CTEPH group compared to IPAH group, was significantly higher (70.7% vs 41.8%)); the distance in T6MX (d6MWT) was 291 [232;385] m vs 379 [300;448] m (p&lt;0.001). CTEPH pts had lower values of sPAP, PVR, SaO2 and SvO2 assessed by RHC. In the switching subgroups 2 of pts with IPAH and CTEPH, achieved levels of sPAP (p=0.01), sRAP (p=0.001) and PVR (p=0.01) (RHC) were significantly lower than in subgroups 1. The baseline levels of CI and SV were significantly higher in subgroups 2 (p&lt;0.05). During riociguat treatment in both subgroups of IPAH, a significant increase in d6MWT was achieved by 6 months with FC I-II (WHO) in 75% and 70% of patients. In the subgroup 1 to 36 months the greatest increase by 97m was achieved; in the switching subgroup the increase in d6MWT was noticed by month 6, which was maintained by month 36. In CTEPH patients, there was a significant improvement in FC (p=0.001) with ∆dT6MX 48m (p=0.001). In subgroup 1 with CTEPH, the d6MWT increase was 68.2m (p = 0.001), reaching 82.6m by month 36. In subgroup 2 the significant change of d6MWT were noted by the 1st year of FU, reaching 136.6m by month 36. In IPAH and CTEPH pts by month 36 of riociguat therapy, a significant decrease of mPAP, SPAP were found by echo, which was confirmed by RHC; there was a decrease in the basal size of the right ventricle (RV) (p=0.04) and an increase in RV FAC (p=0.04 and p=0.03, respectively). In subgroups 1, ∆SvO2 in ts with IPAH and CTEPH were significantly higher compared to subgroups 2. During FU period the proportion of low-risk pts increased to 26.7% in IPAH group and 44.8% in CTEPH group at month 36. In subgroups 2 riociguat therapy resulted in maintenance of treatment regimens throughout the year. Only 6.2% of pts by month 24 and 36 required the prescription of a 3d specific drug. No serious adverse events (AEs) were observed during treatment. The most common AEs were nasopharyngitis, nasal congestion, and dyspnea.Conclusions: Riociguat therapy for 36 months demonstrated a persistent positive effect on the functional and hemodynamic status, remodeling of the right heart both in previously untreated patients with IPH and inoperable CTEPH, and in patients from the switching groups who did not achieve treatment goals with sildenafil therapy.

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.

Can venous blood gas be used instead of arterial blood gas in emergency department?

Objective: In our study, we aimed to evaluate the usability of venous blood gas (VBG) in substitution for arterial blood gas (ABG).&#x0D; &#x0D; Methods: In this study, 110 patients with respiratory complaints, who were brought intubated were evaluated prospectively. Arterial and venous blood gases were taken simultaneously shortly before the initiation of oxygen therapy in the emergency department. PH, pO2, pCO2, SaO2, HCO3, lactate (Lac) and BEecf values were recorded.&#x0D; &#x0D; Results: Of the 110 patients included in the study, 75 were male (68.2%), 35 were female (31.8%), and they had a mean age of 53.7 ± 23.1 years. A strong positive correlation between PH, PCO2, HCO3-, BEecf, Lac values (p=0.001) and positive correlation between PO2 and SaO2 values (p= 0.002) were detected.&#x0D; &#x0D; Conclusion: We can conclude that venous blood gas be used in substitution for arterial blood gas in patients who are presented to emergency service and it may reduce the need for arterial blood gas sampling.

SLAB51 Multi-Strain Probiotic Formula Increases Oxygenation in Oxygen-Treated Preterm Infants.

Preterm infants are at risk of hypoxia and hyperoxia because of the immaturity of their respiratory and antioxidant systems, linked to increased morbidity and mortality. This study aimed to evaluate the efficacy of a single administration of the SLAB51 probiotic formula in improving oxygenation in respiratory distress syndrome (RDS)-affected premature babies, thus reducing their need for oxygen administration. Additionally, the capability of SLAB51 in activating the factor-erythroid 2-related factor (Nrf2) responsible for antioxidant responses was evaluated in vitro. In two groups of oxygen-treated preterm infants with similar SaO2 values, SLAB51 or a placebo was given. After two hours, the SLAB51-treated group showed a significant increase in SaO2 levels and the SaO2/FiO2 ratio, while the control group showed no changes. Significantly increased Nrf2 activation was observed in intestinal epithelial cells (IECs) exposed to SLAB51 lysates. In preterm infants, we confirmed the previously observed SLAB51's "oxygen-sparing effect", permitting an improvement in SaO2 levels. We also provided evidence of SLAB51's potential to enhance antioxidant responses, thus counteracting the detrimental effects of hyperoxia. Although further studies are needed to support our data, SLAB51 represents a promising approach to managing preterm infants requiring oxygen supplementation.

Comparative Analysis of Oxygen Saturation by Pulse Oximetry and Arterial Blood Gas in Hypoxemic Patients in a Tertiary Care Hospital.

Oxygen saturation is essential for medical care and is closely regulated within the body. Arterial blood gas (ABG) analysis is used to evaluate critically ill individuals' ventilation, oxygenation, acid-base status, and metabolic condition. Pulse oximetry is an easy and non-invasive way to measure the status of oxygen saturation non-invasively in clinical settings and provides a quick and precise assessment of oxygenation and reduces medical errors. SpO2 may not always be a reliable predictor of arterial oxygen saturation (SaO2), and hypoxemic, hemodynamically compromised, and critically ill patients may have lower SpO2 accuracy. A study is needed to assess and compare various oxygen saturation methods. The study aimed to compare the oxygen saturation levels measured by pulse oximetry and ABG analysis in hypoxemic patients. The objectives were tocompare the values between SaO2, PaO2, and SpO2 values obtained from the patients, and correlate the study parameters among both techniques. The study was conducted from February 2021 to June 2022 among the 102 hypoxemic patients who were admitted to the emergency and surgical intensive care unit (ICU) of Sree Balaji Medical College and Hospital in Chennai. Primary data on ABGanalysis and pulse oximetry readings were collected from the study subjects. The patient and their past medical records, physical exam, chest x-ray findings, pulse oximetry, and ABG results were all reviewed. Each patient had their ABG, and pulse oximetry measured simultaneously. A comparison was made between SpO2 and partial pressure of oxygen (PaO2) and arterial oxygen saturation (SaO2) parameters using a paired t-test. The correlation was done against the SpO2 and ABG parameters and assessed for association using the correlation coefficient value; gender was also considered while correlating. An observational study was done among 102 study samples to comparatively analyze the oxygen saturation by two methods, namely pulse oximetry and ABG, in hypoxemic patients. While comparing the mean values of SaO2 and SpO2, they were 84.41 ± 4.24 and 80.58 ± 5.77, respectively, and this difference was statistically very significant (p< 0.001). While comparing the mean values of PaO2 and SaO2, they were 61.02 ± 5.01 and 84.41 ± 4.24, respectively, and this difference was statistically significant (p = 0.043). While comparing the mean values of PaO2 and SpO2, they were 61.02 ± 5.01 and 80.58 ± 5.77, respectively, and this difference was statistically significant (p = 0.054). Among the study population, with regard to the correlation factor, there is notably a very high and strong positive correlation between SaO2 and SpO2 and between SpO2 and PaO2. There was a negative correlation between SpO2 and finger abnormalities and between SpO2 and blood pressure. The ABGmethod is considered the gold standard. When SpO2 levels fall below 90%, pulse oximetry may not be accurate enough to reliably assess oxygenation. In such cases, where alveolar hypoventilation is suspected, it is recommended to complement pulse oximetry with ABG studies. This is because ABG analysis provides a more comprehensive assessment of oxygenation and acid-base status, which can aid in the diagnosis and management of respiratory conditions.

A new scoring system to predict mortality in community-acquired pneumonia: CURB (S)-65.

The first decision to be made in the case of community-acquired pneumonia (CAP) is whether hospitalization of the patient is mandatory. In this study, we aimed to investigate whether the addition of oxygenation parameters to CURB-65 has diagnostic value in predicting mortality in CAP. A total of 903 CAP patients were included in the study. Patients with a CURB-65 score of 0 and 1 were classified as Group 1 and patients with a CURB-65 score of 2 or more were classified as Group 2. The prediction of mortality through Pneumonia Severity Index (PSI), CURB-65 and CURBS-65/CURBP-65 with the addition of SaO2 and PaO2 values; hence the four different models, was compared among all patient groups. As a result, 3.3% of the cases in Group 1 and 12.7% of the cases in Group 2 died. In both CURB-65 groups, it was noted that the frequency of patients with SaO2 <90% was significantly higher in the dead group than in the alive patient group (p=0.009 and p=0.001, respectively). In the univariate analysis, PaO2<60, and SaO2<90 were significantly associated with mortality. Model 2 (CURBS-65) and Model 3 (CURBP- 65) were examined, SaO2<90 (OR 2.08) was found to have an effect on death. In predicting mortality by the receiver operating characteristics (ROC) analysis, it was understood that the CURBS-65 score had a slightly higher area under the curve (AUC) value than CURB-65. As a result, it has been shown that the use of CURBS-65 scoring instead of CURB-65 clinical scoring may be more useful in predicting mortality.

Comparison of the efficacy of high-flow oxygen insufflations and continuous positive airway pressure during one-lung ventilation undergoing video-assisted thoracoscopic surgery

Isolation of one-lung leads to ventilation-perfusion mismatch and increases intrapulmonary shunt, which in some cases may lead to clinically significant hypoxemia.The objective was to compare the efficacy of hypoxemia correction and the convenience of surgical work during one-lung ventilation with the use of high-flow oxygen insufflation (HFI) and continuous positive airway pressure (CPAP) in the non-ventilated lung during video-assisted thoracoscopic surgery (VATS).Materials and methods. The study included 60 patients who underwent surgical intervention in the form of VATS lobectomy. All studied patients were randomly divided into two groups: group 1 included patients who received HFI into non-ventilated lung to correct hypoxemia, and group 2 – CPAP into non-ventilated lung. The study was divided into four stages. Stage I – two-lung ventilation. Stage II – one-lung ventilation. At stage III, HFI of 60 L/min (FiO2 = 0,5) into non-ventilated lung was used to correct hypoxemia in group 1, and CPAP of 5 cm H2O into non-ventilated lung was used in group 2. At stage IV, HFI of 30 L/min (FiO2 = 0,5) into non-ventilated lung was used to correct hypoxemia in group 1, and CPAP of 2 cm H2O into non-ventilated lung was used in group 2. The following parameters were recorded during the stages of the study: PaO2, PaCO2, SpO2, Qs/Qt, and surgical team satisfaction with lung collapse by 10-point visual analogue scale (VAS).Results. At stages I and II, there was no statistically significant difference between groups in such parameters as PaO2, PaCO2, SaO2, and SpO2 (p &gt; 0.05). Starting from stage III, a statistically significant difference between the two groups was found for a parameter PaO2 (U 26.0; Z = –6.27; p &lt; 0.001). For group 1, it was equal to 134.5 (126.0; 141.75) and for group 2 – 108.5 (104.0; 114.5) correspondingly. At stage IV, the values of PaO2 were higher in group 1: 118.5 (113.0; 122.25) vs 92.5 (89.0; 98.25) in group 2 (U 0.0; Z = –6.66; p &lt; 0.001). When comparing PaCO2 between the two groups, there were no statistically significant differences at all stages (p &gt; 0.35). When comparing SaO2 at stages I (U 450.0; Z = 0.0; p = 1.0), II (U 422.5; Z = –0.4; p = 0.69), III (U 339.0; Z = –1.8; p = 0.69), no statistically significant differences were indicated between the two groups. However, at stage IV, the value of SaO2 was higher (97 (96; 97)) in group 1 than in group 2 (94 (94; 95)), U 69.5; Z = –5.75; p &lt; 0.001. When comparing SpO2 between the two groups, there was no statistical difference at all stages (p &gt; 0.69). Comparing the two groups by such indicator as Qs/Qt, no statistically significant differences were found at the first three stages (p &gt; 0.4). A comparison of Qs/Qt at stage IV revealed statistically significant differences (U 69.0; Z = –5.6; p &lt; 0.001). This parameter was equal to 10.7% (9.5; 15.7) in group 1 and 21.3% (18.4; 23.9) in group 2 correspondingly. When assessing surgical team satisfaction levels with surgical field visualization by VAS, there were statistically significant differences between group 1 and group 2 at stage III (p &lt; 0.001) and stage IV (p &lt; 0.001). The satisfaction level was significantly higher in group 1.Conclusions. The usage of high-flow oxygen insufflation during one-lung ventilation undergoing VATS allows to effectively correcting hypoxemia similar to the CPAP method, but as opposed to CPAP, it can provide comfortable conditions for carrying out the surgical procedures.

Editor's Choice Articles for June.

Editor's Choice Articles for June.

Validity of the “Roth score” for hypoxemia screening

IntroductionThe Roth score is an alternative strategy to estimate oxygen saturation by using a simple verbal test. We designed this clinical study to assess the validity of the Roth score (Spanish version) as a screening test for hypoxemia. A secondary objective was to evaluate the agreement and consistency between the oxygen saturation obtained via pulse oximetry (SpO2) and arterial blood gas test (SaO2). MethodsAn observational study was conducted in two hospital emergency departments. Adult patients who underwent arterial blood gas tests were included in the analysis. Pulse oximetry values were determined, and the Roth score was applied in the Spanish language. The validity of the Roth score was assessed in terms of sensitivity and specificity by creating ROC curves and by calculating the area under the curve (AUC) for SpO2, SaO2, and oxygen pressure in the arterial blood (PaO2). Agreement between SpO2 and SaO2 values was assessed by using the intraclass correlation coefficient (ICC), and consistency between both measures was calculated by following the method of Bland and Altman. ResultsThe ROC curve models of the Roth score results that were obtained for SaO2 < 90%, ≤92%, and < 95% had AUCs of 0.574, 0.462, and 0.543, respectively, for the highest number that was obtained in the test, as well as AUCs of 0.403, 0.376, and 0.495, respectively, for the maximum time that was used. The AUCs for PaO2 ≤ 60, ≤70, and ≤80 mmHg were 0.534, 0.568, and 0.512, respectively, for the maximum number that was obtained in the test, as well as AUCs of 0.521, 0.515, and 0.519, respectively, for the maximum time that was spent. The ICC between SaO2 and SpO2 was 0.817 (p < 0.001); additionally, the mean difference between the two measurements was −0.55. ConclusionThe Roth score performed in Spanish is not a valid test for hypoxemia screening. There is sufficient agreement and consistency between SaO2 and SpO2 measurements.

A Comparison of Arterial Oxygenation between 60% O&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; CPAP and 100% O&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; CPAP during One-Lung Ventilation: A Prospective Randomized Controlled Study

Background: One-lung ventilation (OLV) is generally adopted for thoracic surgery. The systemic application of a high fraction of inspiratory oxygen (F1O2) and continuous positive airway pressure (CPAP) to the non-ventilated lung is useful for preventing arterial oxygen desaturation. The adverse effects of elevated F1O2 include oxidative lung injury, resorption atelectasis and coronary and peripheral vasoconstriction. It is preferable to avoid hyperoxemia in patients with complications such as chronic obstructive pulmonary disease, idiopathic pneumonia, and bleomycin-treated lungs. We aimed to determine whether the application of 60% O2 CPAP to the non-ventilated lung is sufficient to provide adequate oxygenation with 60% O2 to the ventilated lung. Methods: A total of 70 patients scheduled to receive elective thoracic surgery requiring OLV were recruited. Left double-lumen tubes were applicable in all surgeries. Patients were randomly allocated to one of two groups, to receive either 60% O2 CPAP (60% CPAP group, n = 35), or 100% O2 CPAP (100% CPAP group, n = 35) at a setting of 2 - 3 cmH2O, applied to the non-ventilated lung. Arterial blood gas analyses were obtained at the following stages: RA, spontaneous breathing under room air (RA); TLV, during total lung ventilation (TLV) prior to the initiation of OLV; T5, 5 min after the initiation of OLV; T15, 15 min after the initiation of OLV; T30, 30 min after the initiation of OLV. Results: The PaO2 value in 60% CPAP group vs. 100% CPAP group at each measurement were as follows: RA (mean [standard deviation: SD], 89.7 [8.2] mmHg vs. 85.8 [11.9] mmHg); TLV (277.9 [52.9] mmHg vs. 269.2 [44.0] mmHg); T5 (191.4 [67.9] mmHg vs. 192.3 [66.0] mmHg); T15 (143.2 [67.3] mmHg vs. 154.7 [60.8] mmHg) and T30 (95.6 [32.0] mmHg vs. 112.5 [36.5] mmHg), respectively. Among the five measurement points, T30 was the only time point at which the 100% CPAP group showed a significantly greater PaO2 value than the 60% CPAP group (p = 0.0495). The SaO2 at T30 in the 100% CPAP group (97.4 [2.0]%) was also significantly greater than that in the 60% CPAP group (96.3 [2.2]%, p = 0.039). No differences were found between the groups regarding changes to the overall PaO2 values (p = 0.44) and SaO2 values (p = 0.23) during the study period. Conclusions: Oxygenation could be safely maintained in relatively healthy patients with 60% O2 OLV and 60% O2 CPAP. The application of 60% O2 CPAP during OLV for patients who are not suited to exposure to high F1O2 may be an alternative form of respiratory management.

Racial effects on Masimo pulse oximetry: a laboratory study

Recent publications have suggested that pulse oximeters exhibit reduced accuracy in dark-skinned patients during periods of hypoxemia. Masimo SET® (Signal Extraction Technology®) has been designed, calibrated, and validated using nearly equal numbers of dark and light skinned subjects, with the goal of eliminating differences between pulse oximetry saturation (SpO2) and arterial oxygen saturation (SaO2) values due to skin pigmentation. The accuracy concerns reported in dark-skinned patients led us to perform a retrospective analysis of healthy Black and White volunteers. Seventy-five subjects who self-identified as being racially Black or White underwent a desaturation protocol where SaO2 values were decreased from 100 to 70%, while simultaneous SpO2 values were recorded using Masimo RD SET® sensors. Statistical bias (mean difference) and precision (standard deviation of difference) were − 0.20 ± 1.40% for Black and − 0.05 ± 1.35% for White subjects. Plots of SpO2 versus SaO2 show no significant visible differences between races throughout the saturation range from 70 to 100%. Box plots grouped in 1% saturation bins, from 89–96%, and plotted against concomitant SaO2 values, show that occult hypoxemia (SaO2 < 88% when SpO2 = 92–96%) occurred in only 0.2% of White subject data pairs, but not in any Black subjects. There were no clinically significant differences in bias (mean difference of SpO2-SaO2) found between healthy Black and White subjects. Occult hypoxemia was rare and did not occur in Black subjects. Masimo RD SET® can be used with equal assurance in people with dark or light skin. These laboratory results were obtained in well-controlled experimental conditions in healthy volunteers—not reflecting actual clinical conditions/patients.

Pulse Oximetry and Race in Critically Ill Adults.

OBJECTIVES:For critically ill adults, oxygen saturation is continuously monitored using pulse oximetry (Spo2) as a surrogate for arterial oxygen saturation (Sao2). Skin pigmentation may affect accuracy of Spo2 by introducing error from statistical bias, variance, or both. We evaluated relationships between race, Spo2, Sao2, and hypoxemia (Sao2 < 88%) or hyperoxemia (Pao2 > 150 mm Hg) among adults receiving mechanical ventilation in a medical ICU.DESIGN:Single-center, observational study.SETTING:Medical ICU at an academic medical center.PATIENTS:Critically ill adults receiving mechanical ventilation from July 2018 to February 2021, excluding patients with COVID-19, with race documented as Black or White in the electronic medical record, who had a pair of Spo2 and Sao2 measurements collected within 10 minutes of each other.INTERVENTIONS:None.MEASUREMENTS:We included 1,024 patients with 5,557 paired measurements within 10 minutes, of which 3,885 (70%) were within 1 minute. Of all pairs, 769 (14%) were from Black patients and 4,788 (86%) were from White patients. In analyses using a mixed-effects model, we found that across the range of Spo2 values of 92–98%, the associated Sao2 value was approximately 1% point lower for Black patients compared with White patients. Among patients with a Spo2 value between 92% and 96%, Black patients were more likely to have both hypoxemia (3.5% vs 1.1%; p = 0.002) and hyperoxemia (4.7% vs 2.4%; p = 0.03), compared with White patients.CONCLUSIONS:Among patients with a measured Spo2 of 92–96%, greater variation in Sao2 values at a given Spo2 resulted in a higher occurence rate of both hypoxemia and hyperoxemia for Black patients compared with White patients.

Event-Related Potential Assessment of Visual Perception Abnormality in Patients With Obstructive Sleep Apnea: A Preliminary Study

This study investigated the effect of obstructive sleep apnea (OSA) on the neural mechanism of visual perception. A preliminary case-control study was conducted. Seventeen patients with moderate to severe OSA in the sleep center of Civil Aviation General Hospital and 20 healthy controls matched for age, sex, and education were recruited. The participants accepted the perceptual contour integration task, compared the differences in behavioral indicators between the two groups, and compared the differences in electroencephalography (EEG) data between the two groups through event-related potential (ERP) technology. The groups did not differ significantly in age and gender, but they differed significantly in body mass index (BMI) (OSA higher than healthy controls, p < 0.05). The groups were not statistically different in terms of sleep structure and total sleep time. AHI, sleep efficiency, and minimal SaO2 value in the OSA group were significantly different from those of the control group. The results showed that the average reaction time of the OSA group was significantly longer than that of the healthy control group in the contour integration task. There was no significant difference in the accuracy rate. The results of EEG showed that the amplitudes of N100 of the OSA group were significantly higher than those of the control group at O1, Oz, and O2 electrodes. There was no significant difference in latency between the two groups. At the FCz electrode, the amplitudes of N200 of the OSA group were significantly higher than those of the control group. Therefore, we concluded that in the early stage of the perceptual integration task, although the neural response activity of patients with moderate and severe OSA was not accelerated, they need to call on more psychological resources, activate more neurons in the contour global recognition processing stage, and the compensatory effect of frontal lobe appeared in the stage of visual perception.

Relying on pulse oximetry to avoid hypoxaemia and hyperoxia: A multicentre prospective cohort study in patients with circulatory failure

PurposeThe purpose of this study was to assess the predictive performance of pulse oximetry (SpO2) to rule out hypoxaemia and hyperoxia in critically ill patients. MethodsSpO2, arterial oxygenation (SaO2), and arterial partial pressure of oxygen (PaO2) were prospectively and simultaneously measured every 6 h during the first 24 h of intensive care unit admission in a multicentre cohort of critically ill patients suffering acute circulatory failure. Likelihood ratios associated with different cutoff values of SpO2 to rule out hypoxaemia (SaO2 < 90% or PaO2 < 60 mmHg) or hyperoxia (SaO2 > 95% or PaO2 > 100 mmHg) and post-test probabilities were calculated. Mean bias between SpO2 and SaO2 and agreement interval were calculated. Area under the receiver operating characteristics associated with SpO2 to predict different threshold values of SaO2 and PaO2 were calculated. ResultsFive hundred seventy-one patients (mean [standard deviation] Simplified Acute Physiology Score II: 58.7 [20.1]; mechanically ventilated 75.6%) with 2643 available SaO2 and PaO2 samples and corresponding 2643 SpO2 values were analysed. Mean bias between SpO2 and SaO2 was 1.1%, and its agreement interval ranged from −8.2 to +11.1%. SpO2 cutoff values of 88%, 90%, and 92% left the possibility that 8%–13% of patients had hypoxaemia. SpO2 < 95% left the possibility that 31% of patients had hyperoxia. All calculated areas under the receiver operating characteristics showed a lower limit of their 95% confidence interval below 0.85 ConclusionIn this cohort of patients with circulatory failure, SpO2 had poor discriminative ability to rule out hypoxaemia and hyperoxia. Overconfidence upon SpO2 monitoring may be dangerous.

Impact of ethnicity on the accuracy of measurements of oxygen saturations: A retrospective observational cohort study

SummaryBackgroundPulse oximeters are routinely used in community and hospital settings worldwide as a rapid, non-invasive, and readily available bedside tool to approximate blood oxygenation. Potential racial biases in peripheral oxygen saturation (SpO2) measurements may influence the accuracy of pulse oximetry readings and impact clinical decision making. We aimed to assess whether the accuracy of oxygen saturation measured by SpO2, relative to arterial blood gas (SaO2), varies by ethnicity.MethodsIn this large retrospective observational cohort study covering four NHS Hospitals serving a large urban population in Birmingham, United Kingdom, consecutive pairs of SpO2 and SaO2 measurements taken on the same patient within an interval of less than 20 min were identified from electronic patient records. Where multiple pairs of measurements were recorded in a spell, only the first was included in the analysis. The differences between SpO2 and SaO2 measurements were compared across groups of self-identified ethnicity. These differences were subsequently adjusted for age, sex, bilirubin, systolic blood pressure, carboxyhaemaglobin saturations and the time interval between SpO2 and SaO2 measurements.FindingsPaired O2 saturation measurements from 16,818 inpatient spells between 1st January 2017 and 18th February 2021 were analysed. The cohort self-identified as being of White (81.2%), Asian (11.7%), Black (4.0%), or Other (3.2%) ethnicities. Across the cohort, SpO2 was statistically significantly higher than SaO2 (p < 0.0001), with medians of 98% (interquartile range [IQR]: 95–100%) vs. 97% (IQR: 96–99%), and a median difference of 0.5% points (pps; 95% confidence interval [CI]: 0.5–0.6). However, the size of this difference varied considerably with the magnitude of SaO2, with SpO2 overestimating by a median by 3.8pp (IQR: 0.4, 8.8) for SaO2 values <90% but underestimating by a median of 0.4pp (IQR: -2.0, 1.4) for an SaO2 of 95%. The differences between SpO2 and SaO2 were also found to vary by ethnicity, with this difference being 0.8pp (95% CI: 0.6–1.0, p < 0.0001) greater in those of Black vs. White ethnicity. These differences resulted in 8.7% vs. 6.1% of Black vs. White patients who were classified as normoxic on SpO2 actually being hypoxic on the gold standard SaO2 (odds ratio: 1.47, 95% CI: 1.09–1.98, p = 0.012).InterpretationPulse oximetry may overestimate O2 saturation, and this is possibly more pronounced in patients of Black ethnicity. Prospective studies are urgently warranted to assess the impact of ethnicity on the accuracy of pulse oximetry, to ensure care is optimised for all.FundingPIONEER, the Health Data Research UK (HDR-UK) Health Data Research Hub in acute care.