Minimum SpO2 Research Articles

Evaluation of a portable sleep monitor for the postoperative efficacy of supraglottoplasty in neonates with severe laryngomalacia

Objective:To explore whether a portable monitor device（PMD） can be used to evaluate the efficacy of supraglottoplasty（SGP） in neonates with severe laryngomalacia（LM）. Methods:A retrospective analysis of 11 neonates diagnosed as severe LM treated in our hospital from January 2020 to November 2023 was performed. All neonates underwent SGP under general anesthesia and overnight PMD monitoring before and after surgery.The changes of sleep monitoring parameters before and after surgery were compared, SPSS 18.0 statistical software was applied and Wilcoxon symbolic-rank l test was used. P<0.05 showed statistical difference. Results:One week after surgery, the obstructive apnea-hypopnea index（OAHI）, obstructive apnea index（OAI）, oxygen desaturationindex（ODI） of 11 children were lower than those before operation, and the minimum pulse oximetry saturation（SpO2） was higher than that before operation, P<0.05, the difference was statistically significant, and there was no significant difference in sleep apnea hypopnea index（AHI） compared with that before operation. One month after surgery, AHI, OAHI, OAI and ODI were lower than those before operation, and the minimum SpO2 and mean SpO2 were higher than those before operation, P<0.05, the difference was statistically significant. Conclusion:Some parameters of PMD examination can be used to evaluate the efficacy of SGP in neonatal severe LM, which is an important auxiliary means for the evaluation of neonatal LM.

The 1-minute sit-to-stand test to evaluate fibrotic interstitial lung disease

IntroductionFibrotic interstitial lung diseases (ILD) are a heterogeneous group of conditions. Progression criteria include clinical, imaging, and/or lung functional decline. Currently, the 6-minute walk test (6MWT) is considered the gold standard for assessing exercise-induced desaturation. The 1-minute sit-to-stand test (1STST) has the advantage of being easy to perform, making it feasible for use during clinical consultations. The aim of this study was to compare the 1STST with the 6MWT in patients with fibrotic ILD to detect exercise-induced desaturation. MethodsA multicenter cross-sectional involved patients with fibrotic ILDs from two centers. The 6MWT and 1STST were performed with a 30-minute rest period between the tests. The modified Borg scale was used to assess dyspnea and lower limb fatigue and continuous SpO2 and heart rate were monitored. Desaturation was defined as SpO2 < 90% or decline >3%. ResultsNinety patients were included. The median walking distance in the 6MWT was 432 meters and the median number of repetitions in the 1STST was 22, with a significant correlation (p<0.001, ρ=0.383). In addition, the minimum SpO2 and the desaturation levels recorded during the tests exhibited a moderate significant correlation (p<0.001, ρ=0.502 and p<0.001, ρ=0.537, respectively). There was a strong association between the increase in Borg score for dyspnea and a moderate association between the increase in Borg score for lower limb fatigue after both tests (p<0.001, ρ=0.706 and p<0.001, ρ=0.656, respectively). ConclusionsThis study demonstrates a significant correlation between the 6MWT and the 1STST in detecting exercise-induced desaturation.

Short-term exposure to indoor artificial light at night during sleep impairs cardiac autonomic function of young healthy adults in China

The artificial light at night (ALAN) exposure has emerged as a significant environmental and public health concern globally. However, there is far less evidence on the health effects of indoor ALAN than on outdoor ALAN. Moreover, evidence on cardiovascular effects of indoor ALAN is more limited. To evaluate the association between short-term exposure to ALAN during sleep with heart rate variability (HRV) in young healthy adults, as well as the mediating role of blood oxygen saturation (SpO2), and to further explore the intervention effects of shading habits, this prospective repeated measurement study was conducted among 81 adults with 150 nights (1324h) of HRV monitoring. HRV and SpO2 were monitored during sleep, concurrently with the measurement of indoor and outdoor ALAN. Shading habits were defined as whether to wear blindfolds or draw bed curtains during sleep, and were collected by questionnaires. Linear mixed-effect model was conducted to assess the association between ALAN exposure and HRV indices. The role of SpO2 in the association was analyzed using mediation analyses. We found that indoor ALAN exposure reduced parasympathetic activity and imbalanced cardiac autonomic function. We also found that the use of outdoor ALAN may underestimate or misestimate the potential health effects of ALAN. A significant mediation effects were observed on standard deviation of normal-to-normal intervals (SDNN; p-value for ACME = 0.014) and the ratio of low frequency power to high frequency power (LF/HF; p-value for ACME = 0.026) through minimum SpO2 after indoor ALAN exposure. The association between indoor ALAN and HRV was more pronounced among participants without shading habits during sleep. This study provides general population-based evidence that short-term exposure to indoor ALAN was significantly associated with impaired HRV, and SpO2 partially mediated the association. Improve shading habits during sleep may mitigate the adverse effects of indoor ALAN.

Continuous Positive-Pressure Oxygen Supply Improves Fiberoptic Intubation Efficacy and Safety in Patients With Simulated Cervical Spinal Injury: A Prospective Double-Blind Randomized Controlled Study.

Fiberoptic intubation is an important method for tracheal intubation in patients with cervical spine injury. How to effectively and safely complete fiberoptic intubation while maintaining the stability of the cervical spine is very important. This study compared the efficiency and safety of fiberoptic intubation after anesthesia induction under different types of air pressure in patients with simulated cervical spinal injury. In total, 59 adult patients who underwent fiberoptic intubation with a cervical collar for simulated cervical spinal injury were randomly allocated to continuous positive-pressure oxygen, normal-pressure, or intermittent negative-pressure suction groups. After the induction of anesthesia and adequate 100% oxygenation, which confirmed effective neuromuscular blockade, it was deemed appropriate to begin fiberoptic intubation. In the continuous positive-pressure oxygen group, the fiberoptic device was connected through the negative-pressure suction path with 5 L/min oxygen. In the intermittent negative-pressure suction group, the fiberoptic device was connected to the negative-pressure suction device. In the normal-pressure group, the flexible fiberoptic device was not connected to either the oxygen source or the negative-pressure suction device. The intubation time was recorded as the primary outcome measure. The intubation success rate, number of attempts, minimum SpO2, objective lens contamination rate, and incidence of complications were also compared among the groups. Compared with those in the other groups, the median (range) intubation time in the continuous positive-pressure group was 59 (36-181) seconds, which was significantly shorter than that in the normal-pressure group, 167 (46-181) seconds, and the intermittent negative-pressure suction group, 132.5 (38-181) seconds (P=0.04). The success rate of nasotracheal intubation was significantly greater in the continuous positive-pressure group (94.7%, 18/19) than in the normal-pressure group (50%, 10/20) and intermittent negative-pressure suction group (50%, 10/20) (P=0.004). There was a significant difference among the three groups (P=0.043). The median (range) minimum SpO2 during fiberoptic intubation was 100% (99-100%) in the continuous positive-pressure group, 100% (90-100%) in the normal-pressure group, and 99% (88-100%) in the intermittent negative-pressure suction group (P=0.029). However, no statistically significant difference was detected among the groups with complications. The continuous use of positive-pressure oxygen via the negative-pressure suction pathway can improve the efficiency and safety of fiberoptic intubation in patients with simulated cervical spinal injury after anesthesia induction.

Unveiling the impact of airways: A comparative analysis of oropharyngeal and nasopharyngeal airways in painless fiberoptic bronchoscopy

BackgroundThis study compared the efficacy of oropharyngeal airways (OA) and nasopharyngeal airways (NA) in maintaining oxygenation during painless fiberoptic bronchoscopy (PFB) in patients sedated with remimazolam besylate. MethodsTwo hundred and fifty-two patients were randomized to the OA or NA group. Remimazolam besylate was used for anesthesia induction and maintenance in both groups. We measured and recorded several physiological parameters, including mean arterial pressure, heart rate and oxygen saturation (SpO2), at various time points: before anesthesia (T1), after anesthesia induction (T2), immediately after the bronchoscope reached the trachea (T3), during the procedure (T4), and 5 min after transfer to the post-anesthesia care unit (T5). The incidence and frequency of hypoxemia, minimum SpO2 during the procedure and patient awakening time after flumazenil administration were also recorded. Additionally, the relationship between minimum SpO2 and body mass index (BMI) was investigated. ResultsPatients in the NA group experienced a higher incidence of hypoxemia compared to the OA group. Patients in the OA group maintained higher SpO2 levels at T3 and had a higher minimum SpO2 during the procedure than the NA group. Furthermore, a significant negative correlation was observed between minimum SpO2 and BMI. Following flumazenil anesthesia reversal, nearly 97 % of patients awakened within 1 min. ConclusionsThis study suggests that OA may provide a better safety profile than NA by preserving respiratory function during PFB.

The usefulness of nasal high flow in endoscopic retrograde cholangiopancreatography: A systematic review and meta-analysis

Introduction: Endoscopic Retrograde Cholangiopancreatography (ERCP) is a critical procedure in gastroenterology, typically performed under sedation with the administration of supplemental oxygen. Nasal High Flow (NHF) is a newer method of oxygen administration combined with sedation for oxygen delivery. This meta-analysis was designed to identify the effects of NHF during ERCP. Method: Three major online databases (PubMed, Web of Science, and Cochrane) were searched on July 30, 2024. The search was not limited by publication language and focused on randomized controlled trials that compared the use of NHF with usual care in patients undergoing ERCP. Results: A total of 198 studies were identified after searching the three databases. Finally, five studies, encompassing a total of 581 patients, were included in the meta-analysis. The pooled analysis showed that using NHF was associated with a significantly lower incidence of hypoxemia than usual care. The odds ratio was 0.29 (95% Confidence Interval [CI]: 0.14–0.60, p &lt; 0.001, I² = 21%). The NHF group showed a higher minimum SpO2 value during the procedure, with a 2.55% increase in the mean difference (95% CI: 0.96, 4.13, p = 0.002; I² = 57%). Compared to the usual care group, the NHF group demonstrated a reduction in CO2 partial pressure level at the end of the procedure, with a mean difference of 1.83 mmHg (95% CI: -3.25, -0.42, p = 0.01; I² = 0%). The duration of ERCP showed no statistically significant difference between the usual care group and the NHF group, with a mean difference of 0.7 minutes (95% CI: -0.14, 1.53, p = 0.1; I² = 0%). Conclusion: NHF effectively reduces the incidence of hypoxemia, supporting its consideration as the preferred method of oxygen delivery during ERCP, particularly for patients at higher risk of respiratory complications.

Air or Oxygen for Infant Resuscitation: A Prospective Cohort Study of Moderate-Late Preterm Infants Requiring Delivery Room Resuscitation

Introduction: Due to concerns of oxidative stress and injury, most clinicians currently use lower levels of fractional inspired oxygen (FiO2, 0.21–0.3) to initiate respiratory support for moderate to late preterm (MLPT, 32–36 weeks gestation) infants at birth. Whether this practice achieves recommended oxygen saturation (SpO2) targets is unknown. Methods: We aimed to determine SpO2 trajectories of MLPT infants requiring respiratory support at birth. We conducted a prospective, opportunistic, observational study with consent waiver. Preductal SpO2 readings were obtained during the first 10 min of life from infants between 32 and 36 weeks gestation requiring respiratory support in the delivery room. Primary outcome was reaching a minimum SpO2 80% at 5 min of life. The study was prospectively registered (ACTRN12620001252909). Results: A total of 76 eligible infants were recruited between February 2021 and March 2022 from 5 hospitals in Australia. Most (n = 58, 76%) had respiratory support initiated with FiO2 0.21 (range 0.21–1.0) using CPAP (92%). Median SpO2 at 5 min was 81% (interquartile range [IQR] 67–90) and 93% (IQR 86–96) at 10 min. At 5 min, 18/43 (42%) infants had SpO2 below 80% and only 8/43 (19%) reached SpO2 80–85%. Conclusions: Many MLPT infants requiring respiratory support do not achieve recommended SpO2 targets. In very preterm infants, SpO2 <80% at 5 min of life increases risk of death, intraventricular haemorrhage, and neurodevelopmental impairment. The implications on this practice on the health outcomes of MLPT infants are unclear and require further research.

Comparison of high-flow nasal cannula and conventional nasal cannula during deep sedation for endoscopic submucosal dissection: a randomized controlled trial.

Adequate oxygenation and airway management during deep sedation can be challenging. We investigated the effect of high-flow nasal cannula (group HF) and conventional nasal cannula (group CO) during sedation for endoscopic submucosal dissection (ESD). Patients undergoing ESD with deep sedation were enrolled. The primary outcome was difference in lowest oxygen saturation (SpO2) between the groups. Incidence of hypoxia (SpO2 < 90%), patients with SpO2 < 95%, hypercapnia, and airway interventions; operator satisfaction; and adverse events were recorded. Thirty-two patients in each group completed the study. The mean of minimum SpO2 values was significantly higher in group HF than in group CO (96.8% ± 4.2% vs. 93.3% ± 5.3%, p = 0.005). The incidence of hypoxia was comparable between the groups (4 [12.5%] vs. 6 [18.8%], p = 0.491); however, patients with SpO2 < 95% were significantly less in group HF (5 [15.6%] vs. 18 [56.3%], p = 0.003). Incidence of hypercapnia was higher in group HF than in group CO (14 [46.7%] vs. 5 [16.7%], p = 0.013). Airway rescue interventions were significantly less common in group HF. Satisfaction of operators and post-procedural complications were comparable between the two groups. In multivariable analysis, group CO and higher body mass index were risk factors for airway managements (odds ratio [95% confidence interval]: 6.204 [1.784-21.575], p = 0.004; 1.337 [1.043-1.715], p = 0.022, respectively). Compared to conventional nasal cannula, high-flow nasal cannula maintained higher minimum SpO2 value during deep sedation with propofol-remifentanil for ESD. Clinical Trial Registry of the Republic of Korea (KCT0006618, https://cris.nih.go.kr ; registered September 29, 2021; principal investigator: Ji Won Choi).

Predicting heart failure symptoms from the apnoea-hypopnoea index determined by full- night polysomnography.

Sleep-disordered breathing (SDB) is closely related to cardiovascular diseases. The higher the apnoea-hypopnoea index (AHI), the higher the prevalence of cardiovascular diseases. Despite these findings suggesting a close link between SDB and heart failure, the relationship between the severity of SDB and the onset of heart failure symptoms in individuals without apparent heart failure symptoms (Heart Failure Stage A+B) remains poorly understood. Between December 2010 and June 2017, we conducted full-night polysomnography (PSG) at the Nippon Medical School Chiba Hokusoh Hospital, extracting patients who were at risk of heart failure (Stage A or B in the Heart Failure Guidelines). Using a median cut-off of AHI≥41.6 events/hour, we divided the patients into two groups and examined the composite endpoint of all-cause mortality plus hospitalization due to heart failure as the primary endpoint. We included 230 patients (mean age 63.0±12.5years, 78.3% males) meeting the selection criteria. When comparing the two groups, those with AHI<41.6 events/hour (L group, n=115) and those with AHI≥41.6 events/hour (H group, n=115), the H group had higher body mass index and higher serum triglyceride, and lower the frequency of acute coronary syndrome and lower estimated glomerular filtration rate than did the L group, but no other patient characteristics differed significantly. The H group had a significantly higher incidence of the composite endpoint than did the L group (10.6% vs. 2.6%, P=0.027). Factors associated with the composite endpoint were identified through multivariate analyses, with AHI, haemoglobin, and left atrial dimension emerging as significant factors (hazard ratio [HR]=1.02, 95% confidence interval [CI]=1.00-1.04, P=0.024; HR=0.71, 95% CI=0.54-0.94, P=0.017; and HR=1.10, 95% CI=1.03-1.18, P=0.006, respectively). Conversely, the minimum SpO2 during PSG (<80%) was not associated with the composite endpoint. In patients with SDB who are at risk of heart failure, severe SDB is associated with a high risk of all-cause mortality and the development of heart failure. Additionally, combining cardiac echocardiography and PSG data may improve risk stratification, offering potential assistance for early intervention. Further examination with a validation cohort is necessary.

Evaluation of novel indices of walking performance taking oxygen desaturation into account during six-minute walk test in cardiovascular disease patients.

In pulmonary disease patients since oxygen desaturation during 6-min walk test (6MWT) affects walk distance (6MWD), some novel indices such as desaturation/distance ratio [DDR, oxygen desaturation area (DAO2)/6MWD] and distance-saturation product [DSP, 6MWD × minimum peripheral oxygen saturation (SpO2)] are evaluated. However, there has been no study examining these indices that consider exercise-induced desaturation (EID) in patients with cardiovascular disease. In 94 cardiovascular disease patients without pulmonary complications, 6MWT and echocardiography were performed at the entry of cardiac rehabilitation. SpO2 was measured during 6MWT using a continuously monitorable pulse oximeter, and DSP and DDR were calculated using minimum SpO2 and DAO2 [sum of (100-SpO2) per second during 6MWT], respectively. EID was defined as SpO2 decrease of ≥ 4% or minimum SpO2 of < 90% during 6MWT. DSP was slightly lower and DDR was markedly higher in patients with EID than in those without. When examining correlations of DSP and DDR with their components, DSP was correlated with 6MWD much closely than minimum SpO2, while DDR was correlated as closely with DAO2 as 6MWD. Furthermore, DAO2, but not minimum SpO2, had a direct correlation with 6MWD. As for associations with cardiac function, DSP was correlated with several cardiac parameters, but DDR was not correlated with any of these parameters. Our findings suggest that oxygen desaturation during 6MWT affects walking distance in cardiovascular disease patients even without pulmonary complications and that DDR is more appropriate than DSP as an index of walking performance that takes EID into consideration, independently of cardiac function.

The Efficacy of Noninvasive Ventilation in Patients Affected by Rett Syndrome With Hypoventilation

BackgroundRett syndrome is a progressive neurological disorder associated to several comorbidities that contribute significantly to impair lung function. Respiratory morbidity represents a major cause of death in this population. Little is known about the benefit of noninvasive ventilation. MethodsWe retrospectively enrolled patients with Rett syndrome who underwent a pneumological evaluation combined with a cardiorespiratory polygraphy and/or a pulse oximetry and capnography from 2012 to 2022. ResultsMedical records of 11 patients with Rett syndrome, mean age 13 ± 6 years, were evaluated. Most patients presented with both epilepsy and scoliosis. Five patients showed a pathologic sleep study and/or impaired night gas exchange: mean obstructive apnea-hypopnea index was 4 ± 3 events/hour; mean and minimal SpO2 were, respectively, 93% ± 2% and 83% ± 6%, while mean and maximal transcutaneous carbon dioxide monitoring (PtcCO2) were, respectively, 51 ± 5 mm Hg and 55 ± 8 mm Hg; and mean oxygen desaturation index was 13 ± 11 events/hour. These patients started noninvasive ventilation with clinical benefit and improved gas exchange mostly in terms of PtcCO2 (mean PtcCO2 51 ± 5 mm Hg before and 46 ± 6 mm Hg after noninvasive ventilation). ConclusionsNoninvasive ventilation is a suitable option for patients with Rett syndrome.

Physiologic oxygen responses to smoking opioids: an observational study using continuous pulse oximetry at overdose prevention services in British Columbia, Canada

BackgroundIn British Columbia, Canada, smoking is the most common modality of drug use among people who die of opioid toxicity. We aimed to assess oxygen saturation (SpO2) while people smoked opioids during a pilot study that introduced continuous pulse oximetry at overdose prevention services (OPS) sites.MethodsThis was an observational cohort study, using a participatory design. We implemented our monitoring protocol from March to August 2021 at four OPS. We included adults (≥ 18 years) presenting to smoke opioids. A sensor taped to participants’ fingers transmitted real-time SpO2 readings to a remote monitor viewed by OPS staff. Peer researchers collected baseline data and observed the timing of participants’ inhalations. We analyzed SpO2 on a per-event basis. In mixed-effects logistic regression models, drop in minimum SpO2 ≤ 90% in the current minute was our main outcome variable. Inhalation in that same minute was our main predictor. We also examined inhalation in the previous minute, cumulative inhalations, inhalation rate, demographics, co-morbidities, and substance use variables.ResultsWe recorded 599 smoking events; 72.8% (436/599) had analyzable SpO2 data. Participants’ mean age was 38.6 years (SD 11.3 years) and 73.1% were male. SpO2 was highly variable within and between individuals. Drop in SpO2 ≤ 90% was not significantly associated with inhalation in that same minute (OR: 1.2 [0.8–1.78], p = 0.261) or inhalation rate (OR 0.47 [0.20–1.10], p = 0.082). There was an association of SpO2 drop with six cumulative inhalations (OR 3.38 [1.04–11.03], p = 0.043); this was not maintained ≥ 7 inhalations. Demographics, co-morbidities, and drug use variables were non-contributory.ConclusionsContinuous pulse oximetry SpO2 monitoring is a safe adjunct to monitoring people who smoke opioids at OPS. Our data reflect challenges of real-world monitoring, indicating that greater supports are needed for frontline responders at OPS. Inconsistent association between inhalations and SpO2 suggests that complex factors (e.g., inhalation depth/duration, opioid tolerance, drug use setting) contribute to hypoxemia and overdose risk while people smoke opioids.

Possibilities for predicting the course of fibrosing interstitial lung diseases based on a comprehensive study of the cardio-respiratory system

Introduction. The problem of predicting the course of fibrosing interstitial lung diseases (FILD) is extremely relevant for the timely initiation of the treatment. Aim. To build a prognostic model based on data from a comprehensive study of the cardiorespiratory system in patients with FILD. Material and methods. The study included a group of 40 patients: 18 men and 22 women (M±S 60±9.7 years old), with verified FILD, who completed a full range of clinical and instrumental studies of the cardiorespiratory system at the time of inclusion in the study and after 12 months of observation. Then the initial group was divided into 2 groups: group A (20 patients), which did not reach the combined point, and group B (20 patients), which reached the combined point after 12 months. The combined point consisted of several outcomes: an increase in the degree of dyspnea on the m-MRC scale to 4 points, a deterioration in the results of the 6-minute walk test ≥50 m, a decrease in FVC or TLC ≥10 %, a decrease in the diffusing capacity of the lung for carbon monoxide (DLСO) ≥15 %, the lung transplantation, a death due to the lung disease. Results. Groups A and B did not have any differences in gender, age (А group (M±S) 57±11.8 y. o.; B group (M±S) 63±7.6 y. o., (p=0.06)), structure of the FILD nosology, the therapy and the frequency of the antifibrotic drug prescription. The hard endpoint at 12 months was achieved in 20 of 40 patients (50 %). Patients who reached the combined point were characterized by initially lower lung volumes (VC(M±S) 2.09±0.56 (p=0.016)); FVC (M±S) 1.99±0.55 (p=0.029)), FEV1 (M±S) 1.67±0.37 (p=0.036)), according to the results of a comprehensive study of the pulmonary function; a higher oxygen desaturation index (ODI (M±S) 5.76±4.48 (p=0.022)) and a more pronounced decrease in nocturnal saturation according to the computer pulse oximetry and the cardiorespiratory monitoring (SpO2 (M±S) 81.01±6.74 (p&lt;0.029)). We developed a prognostic model that included such indicators as: post-bronchodilator MOC 75, TAPSE, VE/VCO2 (VO2 peak), desaturation index and minimum SPO2 % (AUC=0.949). Conclusion. The developed prognostic model for the course of FILD, based on the data from the comprehensive study of the cardiorespiratory system, demonstrated high sensitivity (93.8 %) and specificity (87.5 %).

Genetic Influences on Snoring: A Narrative Review

Snoring is a sound that results from vibrations of soft tissues in the narrowed upper airway during sleep. Obstructive sleep apnea (OSA) is a disease entity that must be properly treated. Snoring, which is also considered a symptom of the spectrum of sleep-related breathing disorders, is often overlooked. Although many studies have been conducted on genetic risk factors related to OSA, studies focusing on snoring are limited. Here, we reviewed the literature regarding the influence of genetics on snoring. Initial studies on the influence of genetics on snoring were based on twin and familial studies. Twin studies demonstrated that the phenotypic correlation of snoring between monozygotic twins was greater than that in dizygotic twins, while family history of snoring increases the risk of snoring. Genome-wide association studies showed that traits such as minimum SpO&lt;sub&gt;2&lt;/sub&gt;, umbilical hernia or anthropometric measures such as leg fat mass were genetically correlated to snoring. Traits were mapped and genes such as &lt;i&gt;DLEU7&lt;/i&gt; and &lt;i&gt;MSRB3&lt;/i&gt; have been identified. Snoring is not a disease that should be overlooked. Those with genetic factors increasing the risk of snoring should put more effort into controlling the modifiable risk factor related to snoring.

Physical and Physiological Predictors Determining the Maximal Static Apnea Diving Time of Male Freedivers

This study aimed to investigate what factors determine freedivers' maximal static apnea dive time. We correlated some physical/physiological factors with male freedivers’ maximum apnea diving duration. Thirty-six experienced male freedivers participated in this study. The divers participated in two days of the experiments. On the first day, apnea diving time, blood oxygen saturation (SpO2 ), heart rate (HR), blood pressure (BP), stress index, and blood parameters were measured before, during, and after the apnea diving in the pool. On the second day, body composition, lung capacity, resting and maximal oxygen consumption (VO2 max), and the Wingate anaerobic power were measured in the laboratory. The data were analyzed with Pearson’s Correlation using the SPSS 22 program. The correlation coefficient (R) of determination was set at 0.4, and the level of significance was set at p&lt;0.05. There were positive correlations of diving experience, maximum SpO2 , and lung capacity with the maximum apnea time R&gt;0.4, P&lt;0.05). There were negative correlations of BMI, body fat percentage, body fat mass, minimum SpO2 , stress index, and total cholesterol with the maximum apnea diving time (R&gt;-0.4, P&lt;0.05). No correlations of age, height, weight, fat-free mass, skeletal muscle mass, HR, BP, blood glucose, betahydroxybutyrate, lactate, and hemoglobin levels with the maximum apnea diving time were observed (R&lt;0.4, P&gt;0.05). It is concluded that more experience in freediving, reduced body fat, extended SpO2 range, and increased lung capacity are the performance p

Association between adherence to the mediterranean diet, physical activity, and sleep apnea-hypopnea syndrome (SAHS) in a middle-aged population with cardiovascular risk: Insights from the ILERVAS cohort

IntroductionSleep Apnea-Hypopnea Syndrome (SAHS) is a common sleep disorder influenced by factors like age, gender, and obesity. The Mediterranean Diet (MedDiet) and physical activity have shown health benefits in lung diseases, but their effects on SAHS remain underexplored. MethodsIn a cross-sectional analysis of 678 middle-aged individuals with low-to-moderate cardiovascular risk from the ILERVAS cohort, we assessed adherence to the MedDiet and physical activity levels using validated tools. Sleep parameters, SAHS severity, and excessive daytime sleepiness were evaluated through non-attended cardiorespiratory polygraphy and the Epworth Sleepiness Scale. Multinomial logistic regression models were employed to assess the relationship between MedDiet adherence, physical activity, and SAHS severity. ResultsThe prevalence of severe, moderate, and mild SAHS was 15.5%, 23.2% and 36.1%, respectively. We found no significant associations between adherence to the MedDiet, physical activity levels, and the presence or severity of SAHS. However, we noted a significant interaction between MedDiet and physical activity with minimum SpO2 values (p = 0.049). Notably, consuming more than one serving of red meat per day was independently associated with a higher risk of moderate SAHS [OR = 2.65 (1.29–5.44), p = 0.008]. ConclusionIndividually, MedDiet adherence and physical activity did not show independent correlations with SAHS. However, when considered together, a minimal but significant effect on minimum SpO2 was observed. Additionally, red meat consumption was associated with a moderate risk of SAHS. Further research is necessary to comprehend the intricate connections between lifestyle factors and sleep-breathing disorders, with a focus on personalized approaches for high-risk populations.

Validity and reliability of measurement of peripheral oxygen saturation during the 6-Minute Walk Test in patients with systemic sclerosis

Peripheral oxygen saturation (SpO2) using the fingers may have important limitations due to Raynaud’s phenomenon and sclerodactyly in patients with systemic sclerosis (SSc). Sensors located at more central body positions may be more accurate as these as less prone to Raynaud attacks. To determine the validity and reliability of the SpO2 measured at the finger, forehead, and earlobe during the 6-Minute Walk Test (6MWT). Eighty two patients with SSc had an arterial line placed while performing the 6MWT. Peripheral oxygen saturation was simultaneously measured by finger, forehead, and earlobe sensors and compared to the arterial oxygen saturation (SaO2) measured before and after the 6MWT. 40 patients repeated the 6MWT one week later to determine re-test reliability. We used Bland–Altman plots to display the agreement between SpO2 and SaO2. The intraclass correlation coefficient for repeated measurement of minimum SpO2 was calculated. The mean difference between SpO2 and SaO2 after the 6MWT was − 3% (SD: ± 5), 0% (SD: ± 2), and 1% (SD: ± 2) for the finger, forehead, and earlobe, respectively. The minimum SpO2 measured at the finger demonstrated the poorest re-test reliability: The ICC (95% CI) showed good agreement using the ear and forehead probe (ICCear = 0.89 [95% CI 0.80; 0.94]; ICCforehead = 0.77 [95% CI 0.60; 0.87]), while a modest reliability was found using the finger probe (ICCfinger = 0.65 95% CI [0.43; 0.80]). SpO2 should be measured using either the earlobe or forehead during the 6MWT in patients with SSc. Clinical Trials.Gov (NCT04650659).

Clinical implications of six-minute walk test in patients with idiopathic pulmonary fibrosis: a retrospective cohort study.

A six-minute walk test (6MWT) is a reproducible, easily performed test, and is widely used to determine functional exercise capacity in patients with idiopathic pulmonary fibrosis (IPF). However, there is currently a paucity of data on the clinical significance of baseline and serial 6-minute walk tests in patients with IPF, especially in Asian patients. We aimed to investigate the clinical significance of serial 6MWT in patients with IPF, especially in Asian patients. This is a single-center retrospective cohort study. Clinical data of patients diagnosed with IPF at a tertiary center in Korea were retrospectively analyzed. IPF diagnosis was defined according to the clinical guidelines of the American Thoracic Society (ATS)/European Respiratory Society (ERS)/Japanese Respiratory Society/Latin American Thoracic Association. There were 216 patients diagnosed with IPF from December 2012 to January 2022, of whom 198 had a baseline of 6MWT data. The mean age of the cohort was 66.9 ± 8.6, and 89% were male. The non-survivors showed significantly lower six-minute walk distance (6MWD), minimum saturation of peripheral oxygen (SpO2) during 6MWT, forced vital capacity, and diffusing capacity of the lung for carbon monoxide than survivors at baseline. A multivariate Cox analysis demonstrated that lower minimum SpO2 was independently associated with increased mortality rates (Hazard ratio (HR): 1.081, 95% confidence interval (CI): 1.024-1.142, p = 0.005). Higher mortality rates were also associated with echocardiographic-determined pulmonary hypertension (HR: 2.466, 95% CI: 1.149-5.296, p = 0.021) at diagnosis. Among 144 patients with 6MWT results at 12 months, patients with a decline of 50 m or more in the 6MWD showed poorer overall survival than others (median survival: 45.0 months vs 58.0 months, p < 0.001). Baseline lower minimum SpO2 during 6MWT was an independent prognostic factor in patients with IPF, and a decline in 6MWD in serial follow-up was also associated with a poorer prognosis. These findings suggest that both baseline 6MWT and follow-up data are important in the prognostication of patients with IPF.

The association between high-oxygen saturation and prognosis for intracerebral hemorrhage.

Concerns about the adverse effects of excessive oxygen have grown over the years. This study investigated the relationship between high oxygen saturation and short-term prognosis of patients with spontaneous intracerebral hemorrhage (sICH) after liberal use of oxygen. This retrospective cohort study collected data from the Medical Information Mart for Intensive Care III (MIMIC-III) database (ICU cohort) and a tertiary stroke center (general ward cohort). The data on pulse oximetry-derived oxygen saturation (SpO2) during the first 24 h in ICU and general wards were respectively extracted. Overall, 1117 and 372 patients were included in the ICU and general ward cohort, respectively. Among the patients from the ICU cohort, a spoon-shaped association was observed between minimum SpO2 and the risk of in-hospital mortality (non-linear P<0.0001). In comparison with minimum SpO2 of 93-97%, the minimum SpO2>97% was associated with a significantly higher risk of in-hospital mortality after adjustment for confounders. Sensitivity analysis conducted using propensity score matching did not change this significance. The same spoon-shaped association between minimum SpO2 and the risk of in-hospital mortality was also detected for the general ward cohort. In comparison with the group with 95-97% SpO2, the group with SpO2>97% showed a stronger association with, but non-significant risk for, in-hospital mortality after adjustment for confounders. The time-weighted average SpO2>97% was associated significantly with in-hospital mortality in both cohorts. Higher SpO2 (especially a minimum SpO2>97%) was unrewarding after liberal use of oxygen among patients with sICH and might even be potentially detrimental.

Predictive values of Mallampati score, tonsillar size, and BMI z-score in the presence and severity of obstructive sleep apnea in pediatric population.

Obstructive sleep apnea (OSA) is a common sleep-related breathing disorder in children. Determination of risk factors for the development of OSA is essential for early diagnosis and treatment of the disease and decreases the risk of negative consequences. This study aimed to investigate the predictive values of Mallampati score, tonsillar size, and BMI z-score in the presence and severity of OSA in children. This prospective cross-sectional study included 114 children with OSA symptoms. All children were assessed by BMI z-score, Mallampati score, and tonsillar size and underwent overnight polysomnography. They were consecutively selected and assigned to 4 groups as follows: Group 1 included normal-weight with a low Mallampati score; Group 2 involved normal-weight with a high Mallampati score; Group 3 included obese with a low Mallampati score; and Group 4 involved obese with a high Mallampati score. Of the 114 included children, 58 were female and 56 were male, with a mean age of 13.1 ± 2.9 years. OSA frequency and apnea-hypopnea index were significantly higher in group 4 compared with other groups (p = 0.003 and p < 0.0001, respectively), whereas average and minimum spO2 were significantly lower (for both, p = 0.001). Mallampati score and BMI z-score were found to be significant for predicting OSA (odds ratio = 4.147, 95% CI: 1.440-11.944; p = 0.008 and odds ratio = 1.760, 95% CI: 1.039-2.980; p = 0.035, respectively). Among OSA patients, the Mallampati score, tonsillar size, and BMI z-score were found to be significant for predicting OSA severity (odds ratio = 4.520, 95% CI: 1.332-15.335, p = 0.015, odds ratio = 9.177, 95% CI: 2.513-33.514, p = 0.001, and odds ratio = 2.820, 95% CI: 1.444-5.508; p = 0.002, respectively). The coexistence of the Mallampati score and BMI z-score significantly increases the presence of OSA in children. Mallampati score, tonsillar size, and BMI z-score are promising parameters for predicting OSA severity.