SaO2 Values Research Articles

Statistical Description of SaO2–SpO2 Relationship for Model of Oxygenation in Premature Infants

A pulse oximeter model linking arterial (SaO2) and peripheral (SpO2) oxygen saturation is the terminal part of a mathematical model of neonatal oxygen transport. Previous studies have confirmed the overestimation of oxygen saturation measured by pulse oximetry in neonates compared to arterial oxygen saturation and the large variability of measured values over time caused by measurement inaccuracies. This work aimed to determine the SpO2 measurement noise that affects the biased SpO2 value at each time point and integrate the noise description with the systematic bias between SaO2 and SpO2. The SaO2–SpO2 bias was based on previously published clinical data from pathological patients younger than 60 days requiring ventilatory support. The statistical properties of the random SpO2 measurement noise were estimated from the SpO2 continuous recordings of 21 pathological and 21 physiological neonates. The result of the work is a comprehensive characterization of the properties of a pulse oximeter model describing the transfer of the input SaO2 value to the output SpO2 value, including the bias and noise typical for the bedside monitoring of neonates. These results will help to improve a computer model of neonatal oxygen transport.

Cycling for Weight Loss May Clear Carbohydrates Rather Than Fat, Irrespective of Normal or Mildly Reduced Normobaric Oxygen

A single-center randomized, controlled cross-over exercise intervention in 20 women willing to reduce weight (20–40 y, BMI: 27.4 ± 2.1), with the aim to examine potential benefits for weight loss under normal (N-Ox: 20.9%) and mildly reduced (R-Ox: 17.0%) normobaric oxygen in an “Altitude Simulation Chamber”. O2 consumption (VO2), CO2 production (VCO2), blood oxygen saturation (SaO2), blood glucose and lactate (mM) were studied before, during and after cycling for 22 min at a mean personalized workload of 54.2 ± 11.7 watts, about 40% of VO2max. Despite lower absolute SaO2 values and a greater decline from rest to exercise under R-Ox (time x treatment interaction p < 0.01), VO2 did not differ from N-Ox (time x treatment interaction p = 0.178). Average net VO2, 13.8 mL O2 per watt, reflected fairly normal aerobic cycling, irrespective of O2 regime. The Respiratory Exchange Ratio (RER; VO2/VCO2), 0.83 at rest, increased for both treatments to a ratio close to or beyond unity during and directly after exercise (treatment effect p = 0.407). The tendency of cycling for weight loss to clear carbohydrates rather than fat, irrespective of normal or mildly reduced normobaric oxygen, is discussed as a lactate-mediated and phenotype-specific consequence of apparent anaerobic glycolysis with adverse perspectives for weight loss and metabolic health.

Coexistence of obstructive sleep apnea syndrome and fibromyalgia.

Fibromyalgia is characterized by pain all over the body, whose diagnosis and treatment are not fully understood. Obstructive sleep apnea syndrome (OSAS) is a disease that causes apnea, hypopnea and oxygen desaturation due to collapse in the upper respiratory tract and is characterized by excessive daytime sleepiness, fatigue and lack of attention. Symptoms and signs of OSAS and fibromyalgia are similar. In our study, we aimed to compare the association of fibromyalgia in female OSAS patients in terms of polysomnography and laboratory parameters. We aimed to examine the association of fibromyalgia in patients with female OSAS. A total of 190 female OSAS patients were included in the study. The patients were divided into two groups according to the presence of fibromyalgia: 88 (46.3%) patients in the fibromyalgia group and 102 (53.7%) patients in the control group. Statistical Package for the Social Sciences (SPSS) program was used for the evaluation of demographic data, polysomnography parameters and laboratory tests of the patients, and values with p<0.05 were considered statistically significant. Mean age of the patients was 52.1 ± 11.9 years and mean body mass index (BMI) was 35.1 ± 7.2. There was no difference between age and BMI (p= 0.971, p= 0.716, respectively). Periodic leg movements (PLMS) were higher in the fibromyalgia group (p= 0.02). The desaturation index (CT90) was found to be high in the fibromyalgia group (p= 0.043). The minimum SaO2 value was found to be low in the fibromyalgia group (p= 0.022). Sleep latency was found to be higher in the fibromyalgia group (p= 0.031). Hemoglobin and hematocrit values were found to be statistically significantly higher in the fibromyalgia group (p= 0.020, p= 0.027, respectively). Triglyceride level was found to be high in the fibromyalgia group (p= 0.043). We recommend clinical evaluation of female patients with fibromyalgia and we suggest polysomnography, especially in patients with excessive daytime sleepiness. Early diagnosis and treatment of concomitant OSAS will contribute to quality of fibromyalgia patients' life.

The Clinical Effect of High-Flow Oxygen Therapy through the Nose on Patients with Acute Left Heart Failure and Hypoxemia.

Objective To evaluate the clinical efficacy of nasal high-flow oxygen therapy in patients with acute left heart failure and hypoxemia. Methods From July 2016 to November 2018, patients with acute left heart failure complicated with hypoxemia treated in the Department of Critical Medicine of Yantai Affiliated Hospital of Binzhou Medical University were retrospectively observed (a total of 140 cases met the inclusion criteria). They were randomly divided into two groups, with 70 cases in each group. Patients were given continuous ECG monitoring, improved blood gas analysis test, and recorded HR, RR, map, SaO2, pH, PaO2, PaCO2, and Lac, perfect examination and color Doppler echocardiography, and record NT-proBNP and EF before and 24 hours after treatment. The effective rates of the two groups before and after oxygen therapy were detected. Results There were 67 patients with high-flow oxygen therapy group improvement, 95.7% improvement rate, and 55 patients with general oxygen therapy group improvement rate. The treatment improvement rate was 78.6%. A total of 67 patients were treated with high-flow oxygen therapy. After high-flow oxygen therapy, HR (t = 18.8, P ≤ 0.05), RR (t = 19.7, P ≤ 0.05), MAP (t = 12.1, P ≤ 0.05), PaCO2 (t = 9.53, P ≤ 0.05), Lac (t = 8.69, P ≤ 0.05), and NT-proBNP (t = 7.03, P ≤ 0.05) were significantly lower than before. SaO2 (t = −12.4, P ≤ 0.05), pH (t = −12.2, P ≤ 0.05), PaO2 (t = −17.7, P ≤ 0.05), and EF (t = −13.4, P ≤ 0.05) were significantly higher than before. A total of 55 patients were in the general oxygen therapy group. After administration of ordinary oxygen therapy, HR (t = 18.2, P ≤ 0.05), RR (t = 10.8, P ≤ 0.05), MAP (t = 13.1, P ≤ 0.05), PaCO2 (t = 15.8, P ≤ 0.05), Lac (t = 7.1, P ≤ 0.05), and NT-proBNP (t = 10, P ≤ 0.05) were significantly lower than before. SaO2 (t = −15.5, P ≤ 0.05), pH (t = −4.5, P ≤ 0.05), PaO2 (t = −20, P ≤ 0.05), and EF value (t = −7.7, P ≤ 0.05) were significantly higher than before. Conclusion High-flow oxygen therapy and general oxygen therapy have an obvious curative effect on patients with acute left heart failure and hypoxemia. Compared with the two, high-flow oxygen therapy is more effective. After high-flow oxygen therapy and general oxygen therapy in patients with acute left heart failure and hypoxia, HR, RR, MAP, SaO2, pH, PaO2, PaCO2, Lac, EF, and NT-proBNP value all improved, and the improvement of high-flow oxygen therapy was greater.

Self-reported Race/Ethnicity and Intraoperative Occult Hypoxemia: A Retrospective Cohort Study.

Pulse oximetry is ubiquitous in anesthesia and is generally a reliable noninvasive measure of arterial oxygen saturation. Concerns regarding the impact of skin pigmentation and race/ethnicity on the accuracy of pulse oximeter accuracy exist. The authors hypothesized a greater prevalence of occult hypoxemia (arterial oxygen saturation [Sao2] less than 88% despite oxygen saturation measured by pulse oximetry [Spo2] greater than 92%) in patients undergoing anesthesia who self-reported a race/ethnicity other than White. Demographic and physiologic data, including self-reported race/ethnicity, were extracted from a departmental data warehouse for patients receiving an anesthetic that included at least one arterial blood gas between January 2008 and December 2019. Calculated Sao2 values were paired with concurrent Spo2 values for each patient. Analysis to determine whether Black, Hispanic, Asian, or Other race/ethnicities were associated with occult hypoxemia relative to White race/ethnicity within the Spo2 range of 92 to 100% was completed. In total, 151,070 paired Sao2-Spo2 readings (70,722 White; 16,011 Black; 21,223 Hispanic; 8,121 Asian; 34,993 Other) from 46,253 unique patients were analyzed. The prevalence of occult hypoxemia was significantly higher in Black (339 of 16,011 [2.1%]) and Hispanic (383 of 21,223 [1.8%]) versus White (791 of 70,722 [1.1%]) paired Sao2-Spo2 readings (P < 0.001 for both). In the multivariable analysis, Black (odds ratio, 1.44 [95% CI, 1.11 to 1.87]; P = 0.006) and Hispanic (odds ratio, 1.31 [95% CI, 1.03 to 1.68]; P = 0.031) race/ethnicity were associated with occult hypoxemia. Asian and Other race/ethnicity were not associated with occult hypoxemia. Self-reported Black and Hispanic race/ethnicity are associated with a greater prevalence of intraoperative occult hypoxemia in the Spo2 range of 92 to 100% when compared with self-reported White race/ethnicity.

Nedocromil sodium and diphenhydramine HCl ameliorate exercise-induced arterial hypoxemia in highly trained athletes.

IntroductionExercise‐induced arterial hypoxemia (EIAH) has been observed in highly trained endurance athletes during near maximal exercise, which may be influenced by a histamine‐mediated inflammatory response at the pulmonary capillary‐alveolar membrane. In order to test this hypothesis, we examined whether the mast cell stabilizer nedocromil sodium (NS) and H1‐receptor antagonist diphenhydramine HCL (DH) would ameliorate EIAH and mitigate the drop in arterial oxyhemoglobin saturation (SaO2) during intensive exercise.MethodsSeven highly trained male cross country runners (age, 21 ± 2 years; V̇O2max, 74.7 ± 3.5 ml·kg−1·min−1) participated in the study. All subjects completed a maximal exercise treadmill test to exhaustion, followed by three 5‐min constant‐load exercise bouts at 70%, 80%, and 90% V̇O2max. Prior to testing, subjects received either placebo (PL), NS, or DH.ResultsCompared to PL, there was a significant treatment effect on SaO2 (p < 0.001) for both NS and DH during both constant‐load exercise and at V̇O2max. Post hoc tests revealed SaO2 values, compared to PL, were significantly higher at V̇O2max and during DH trials and higher with NS at constant‐load intensities except at 70% (p = 0.13).ConclusionThe findings provide further evidence that histamine contributes directly or indirectly to the development of EIAH during intense exercise in highly trained athletes.

Prevalence, characteristics, and respiratory arousal threshold of positional obstructive sleep apnea in China: a large scale study from Shanghai Sleep Health Study cohort

PurposeTo evaluate the prevalence, characteristics, and respiratory arousal threshold (ArTH) of Chinese patients with positional obstructive sleep apnea (POSA) according to the Cartwright Classification (CC) and Amsterdam Positional Obstructive Sleep Apnea Classification (APOC).MethodsA large-scale cross-sectional study was conducted in our sleep center from 2007 to 2018 to analyze the clinical and polysomnography (PSG) data of Chinese POSA patients. Low ArTH was defined based on PSG indices.ResultsOf 5,748 OSA patients, 36.80% met the CC criteria, and 42.88% the APOC criteria, for POSA. The prevalence of POSA was significantly higher in women than men (40.21% and 46.52% vs. 36.13% and 42.18% for CC and APOC, respectively). Chinese POSA patients had a lower apnea hypopnea index (AHI) and lower oxygen desaturation index, shorter duration of oxygen saturation (SaO2) < 90%, and a higher mean SaO2 and higher lowest SaO2 value compared to subjects with non-positional OSA (NPOSA). More than 40% of the POSA patients had a low ArTH; the proportion was extremely high in the supine-isolated-POSA (si-POSA) group and APOC I group. In multivariate logistic regression analyses, higher mean SaO2 and lower AHI during sleep were positive predictors of POSA.ConclusionsAccording to the CC and APOC criteria, more than 1/3 of our Chinese subjects with OSA had POSA. Chinese POSA patients had less severe OSA and nocturnal hypoxia. Compared to NPOSA patients, significantly more patients with POSA had a low ArTH. A low ArTH may be an important endotype in the pathogenesis of POSA, especially in patients with si-POSA and APOC I. Further studies are necessary to develop personalized management strategies for POSA patients.Trial registration: Chinese Clinical Trial Registry; URL: http://www.chictr.org.cn; No. ChiCTR1900025714 (retrospectively registered).

COMPARISON OF EFFECTS OF INCENTIVE SPIROMETRY AND DEEP BREATHING EXERCISES ON PULMONARY FUNCTIONS AFTER CORONARY ARTERY BYPASS GRAFTING

OBJECTIVE: To compare the effects of incentive spirometry (IS) and deep breathing exercises (DBE) on pulmonary functions after coronary artery bypass grafting (CABG).&#x0D; METHODS: This quasi-experimental study consisted of 40 patients from both genders aged 35-60 years, undergoing CABG. Two equal groups were selected through convenient sampling. Group-A patients performed IS while group-B performed DBE. The outcome measures were values of oxygen saturation (SaO2)by pulse oximetry, and partial pressures of oxygen (pO2) and carbon dioxide (pCO2) measured by arterial blood gases (ABGs).&#x0D; RESULTS: Mean pO2 (mmHg) at day 1 &amp; day 4 was 136±23.04 &amp; 74.42±16.22 respectively in group-A (p&lt;0.001) as compared to 127.96 ±16.99 &amp; 70.80±10.89 respectively in group-B (p&lt;0.001). Mean value of SaO2 at day 1 &amp; day 4 was 98.52±1.68 &amp; 94.07±2.36 in group-A (p&lt;0.001) as compared to 97.90±1.99 and 95.40±2.04 in group-B (p&lt;0.001) respectively. Mean pCO2 (mmHg) was 42.32±4.57 &amp; 40.07±3.49 at day 1 &amp; day 4 in group-A (p&lt;0.05) and 40.85±4.03 &amp; 39.61±3.40 in group-B (p&gt;0.05) respectively. Common complications observed were atelectasis (n=29/40; 72.5%), pleural effusion (n=6/40; 15%) and pulmonary edema (n=5/40; 12.5%). Majority (n=19; 47.5%) of patients were discharged till 5th postoperative day. Median stay at hospital was 3 days in group-A &amp; 4 days in group-B.&#x0D; CONCLUSION: There was an improvement in ABGs and SaO2 after CABG surgery in patients receiving chest physiotherapy interventions. Both techniques are equally effective in preventing and treating chest complications in patients having CABG.

The effect of patient ethnicity on the accuracy of peripheral pulse oximetry in patients with COVID-19 pneumonitis: a single-centre, retrospective analysis.

SummaryPulse oximetry is used widely to titrate oxygen therapy and for triage in patients who are critically ill. However, there are concerns regarding the accuracy of pulse oximetry in patients with COVID‐19 pneumonitis and in patients who have a greater degree of skin pigmentation. We aimed to determine the impact of patient ethnicity on the accuracy of peripheral pulse oximetry in patients who were critically ill with COVID‐19 pneumonitis by conducting a retrospective observational study comparing paired measurements of arterial oxygen saturation measured by co‐oximetry on arterial blood gas analysis (SaO2) and the corresponding peripheral oxygenation saturation measured by pulse oximetry (SpO2). Bias was calculated as the mean difference between SaO2 and SpO2 measurements and limits of agreement were calculated as bias ±1.96 SD. Data from 194 patients (135 White ethnic origin, 34 Asian ethnic origin, 19 Black ethnic origin and 6 other ethnic origin) were analysed consisting of 6216 paired SaO2 and SpO2 measurements. Bias (limits of agreement) between SaO2 and SpO2 measurements was 0.05% (−2.21–2.30). Patient ethnicity did not alter this to a clinically significant degree: 0.28% (1.79–2.35), −0.33% (−2.47–2.35) and −0.75% (−3.47–1.97) for patients of White, Asian and Black ethnic origin, respectively. In patients with COVID‐19 pneumonitis, SpO2 measurements showed a level of agreement with SaO2 values that was in line with previous work, and this was not affected by patient ethnicity.

Accuracy of two pulse-oximetry measurements for INTELLiVENT-ASV in mechanically ventilated patients: a prospective observational study

Recently, maintaining a certain oxygen saturation measured by pulse oximetry (SpO2) range in mechanically ventilated patients was recommended; attaching the INTELLiVENT-ASV to ventilators might be beneficial. We evaluated the SpO2 measurement accuracy of a Nihon Kohden and a Masimo monitor compared to actual arterial oxygen saturation (SaO2). SpO2 was simultaneously measured by a Nihon Kohden and Masimo monitor in patients consecutively admitted to a general intensive care unit and mechanically ventilated. Bland–Altman plots were used to compare measured SpO2 with actual SaO2. One hundred mechanically ventilated patients and 1497 arterial blood gas results were reviewed. Mean SaO2 values, Nihon Kohden SpO2 measurements, and Masimo SpO2 measurements were 95.7%, 96.4%, and 96.9%, respectively. The Nihon Kohden SpO2 measurements were less biased than Masimo measurements; their precision was not significantly different. Nihon Kohden and Masimo SpO2 measurements were not significantly different in the “SaO2 < 94%” group (P = 0.083). In the “94% ≤ SaO2 < 98%” and “SaO2 ≥ 98%” groups, there were significant differences between the Nihon Kohden and Masimo SpO2 measurements (P < 0.0001; P = 0.006; respectively). Therefore, when using automatically controlling oxygenation with INTELLiVENT-ASV in mechanically ventilated patients, the Nihon Kohden SpO2 sensor is preferable.Trial registration UMIN000027671. Registered 7 June 2017.

Physiological impact of wearing a surgical face mask during walking in the COVID-19 pandemic

Background and Study Aim. Common use of surgical face masks is recommended for social and individual health due to the COVID-19 pandemic. However, there is no systematic report for responses of organism to wearing a surgical face mask during different exercises. In this context the purpose of this study was to examine the impacts of wearing a surgical face mask during a one-hour brisk walking.&#x0D; Material and Methods. A total of thirty male (n=16) and female (n=14) volunteers (mean age and BMI of 32±1.07 years and 25.1±0.68 kg/m2, respectively) completed the protocol. This was a multiple cross-over trial for healthy volunteers. All participants took a one-hour brisk walking with and without a surgical face mask. Specific physiological measurements (HR - heart rate; BP - blood pressure, SaO2 - arterial oxygen content) were compared before and immediately after two brisk walking. Each subject served their own control.&#x0D; Results. The evaluation found that there was no statistically significant difference between the mean HR and blood pressure values during the brisk walking with and without a surgical face mask, while there was a statistically significant difference in the SaO2 values on behalf of no-mask-walking (p&lt;0.05).&#x0D; Conclusions. The use of surgical face masks in healthy volunteers causes a decrease in SaO2 during brisk walking. However, it does not affect the mean pulse rate and blood pressure. Although there was a statistically significant decrease in the SaO2 parameter during mask-walking, it is possible to state that brisk walking with a surgical face mask does not have a physiologically negative impact, because this decrease is in ranges that are accepted to be normal.

Blood gas analysis of healthy people in Diqing Tibetan Autonomous Prefecture in Yunnan Province

To investigate the reference value of blood gas analysis and related factors in healthy adults in Diqing Tibetan Autonomous Prefecture in Yunnan Province. From August 24, 2018 to August 11, 2020, healthy people between the ages of 18 and 70 years were observed at the Physical Examination Center of People's Hospital of Diqing Tibetan Autonomous Prefecture in Yunnan province. Participant information and clinical characteristics were collected. Blood gas analyzer was used to measure PH value, arterial partial oxygen pressure (PaO2), arterial partial pressure of carbon dioxide (PaCO2), arterial oxygen saturation (SaO2), acidity (pH), actual bicarbonate (AB) and residual base (BE). The participants' basic and blood gas indicator data were analyzed, and the blood gas reference values and related factors were analyzed using chi-squared tests, Mann-Whitney-Wilcoxon Test, and Spearman's correlation analysis. A total of 1,218 eligible health examination participants were included. They had an average age of 40 [31-47] years, and males accounted for 51.0%. In terms of blood gas reference values, the average pH value was moderate, and the values of PaO2, SaO2, PaCO2, AB, and BE were low. PaO2 was basically matched with the estimated value of the domestic model formula. These indexes were found to be correlated with social demographic characteristics such as sex, age, and smoking history. The correlations between the indexes and social demographic characteristics may be helpful in the prediction of blood gas analysis results in clinical practice. For men, middle-aged and elderly people, or adults with a history of active smoking/biofuel exposure, blood gas PaO2 and PaCO2 should be monitored to facilitate the early intervention of respiratory failure. The PaO2 data basically matched the estimated values of the domestic model formula, suggesting that other regions in the Prefecture could use comprehensive epidemiological data and model methods to guide clinical work.

The Effectiveness of 6 Months Hydrotherapy Program Based on Halliwick Concept on the Respiratory System of Down Syndrome Children

The aim of the study was to investigate the effect of a hydrotherapy program on FVC, FEV, PEF, RR and SaO2 on children with Down syndrome over six months and to compare it with a conventional respiratory physiotherapy program. Eighteen children, with Down Syndrome, aged 6 - 11 years (9.53 ± 0.454), divided into two groups of nine, the intervention group (IG), that participated in the hydrotherapy program and the control group (CG) participated in the classical physiotherapy program. We calculated mean values of FVC, FEV, PEF, RR and SaO2 before and after six months intervention for both groups. There was a statistically significant improvement in all factors for both groups. However, were statistically more significant for the intervention group (IG). Based on a specific protocol of intervention in the water and at the same time with a group of children who participated in a similar program of classical respiratory physiotherapy, it was found to be statistically more important than the second group in improving respiratory function. We recommend the use of hydrotherapy as a complementary therapy that should be part of the weekly program of these children in addition to the existing treatments they attend.

Effect of training on the development of exercise-induced arterial hypoxemia in volleyball players

Background and Study Aim. The purpose of this study was to examine the effect of volleyball training on the development of exercise-induced arterial hypoxemia during incremental exercise in male competitive volleyball players.&#x0D; Material and Methods. Eight male amateur volleyball players (age 21±1.3 years) participated in a 6-week volleyball training program three times a week in the pre-season preparatory period. Before and after the training period, all players performed an incremental treadmill test to determine maximal oxygen uptake (VO2max), and oxyhemoglobin saturation (SaO2) was continuously measured using a pulse oximeter during the test. Maximal values of minute ventilation (VEmax), respiratory exchange ratio (RERmax), ventilatory equivalent for oxygen (VE/VO2) and carbon dioxide (VE/VCO2) were determined. Exercise-induced arterial hypoxemia (EIAH) was defined as a SaO2 decreased by at least 4% (ΔSaO2≤ −4%) from resting level.&#x0D; Results. All the players exhibited exercise-induced arterial hypoxemia before (ΔSaO2= –8.8±3.3%) and after (ΔSaO2= –8.31.5%) the training period. SaO2 was significantly decreased from 97.6±1% at rest to 88.7±2.7% at exhaustion before the training period, and from 97.2±1.1% at rest to 88.8±2.1% at exhaustion after training period (p &lt; 0.001). There was no significant difference in resting and lowest SaO2 values by comparison between the before and after training (p &gt; 0.05). There were no significant changes in VO2max, VEmax, RERmax, VE/VO2 and VE/VCO2 after training period (p &gt; 0.05).&#x0D; Conclusions. The results of this study showed that volleyball players with a history of anaerobic training may exhibit EIAH, but that 6-week volleyball training has no effect on the degree of exercise-induced arterial hypoxemia.

Circadian Melatonin Secretion In Obese Adolescents With Or Without Obstructive Sleep Apnea

Objective — To compare melatonin levels in saliva during a 24-hr day in order to identify the specificities of circadian melatonin secretion in obese adolescents with or without obstructive sleep apnea (OSA). Material and Methods — We examined 18 obese adolescents with OSA, 12 obese adolescents without OSA, and 15 healthy adolescents with a normal body weight, from whom saliva was sampled four time during the 24-hr day. Polysomnography was used to diagnose OSA. Saliva samples (n=180) were subjected to enzyme-linked immunosorbent assay. Results — Obese adolescents with OSA had higher evening melatonin levels than obese adolescents without OSA. For example, this indicator in OSA patients was 5.3 times higher than in participants without OSA, who had the lowest evening melatonin level among all groups. In both obese groups, nighttime melatonin levels were significantly lower than in the control group. A positive correlation was detected between the levels of morning and afternoon melatonin and body mass index only in obese adolescents without OSA (r=0.58; p=0.03 and r=0.68; p=0.01, respectively). It was found that evening melatonin correlated with minimum blood oxygen saturation (SaO2) in the entire sample of adolescents with OSA (r=-0.69; p=0.008), and it also correlated with time with SaO2 &lt;90% in the group with clinical manifestations of OSA (r=0.76; p=0.003). Nighttime melatonin levels negatively correlated with the minimum SaO2 value solely in the group with clinical manifestations of OSA (r=-0.58; p=0.035). Conclusion — The circadian melatonin secretion in obese adolescents differed, depending on the presence or absence of OSA, and correlated with the level of oxygen desaturation in OSA patients, to a greater extent – in the presence of clinical manifestations.

The Pivotal Role Of Coconut Oil Or Liquid Paraffin As Antidote Effective In Reducing Acute Aluminum Phosphide Poisoning In Cardiogenic Shock

Abstract Introduction/Objective Aluminum phosphide (Alp) is a self-poisoning agent for raising the mortality rates in developing countries. Alp is known as “Rice-tablet” which is a cheap solid fumigant pesticide that is used for grain preservation which becomes a common mode of suicidal attempts in the rural community in Egypt. This study aims to identify the mechanism of salient features and management strategies were carried out on acute Alp-poisoned patients at Poison-Emergency-Unit, ElBehira-Hospitals. That was performed between Jan2018-Jun2019. Methods Patients were subjected to a full history evaluation of age, sex, Blood gases, and ECG, were demonstrated. Patients were grouped according to their outcome into survivors and non-survivors groups. Results The results demonstrated that (93%) of Alp-poisoning cases by oral-ingestion as suicidal attempts which were (54%) survived while (46%) non-survived. The blood-gases were showed that over 50% of the cases had metabolic acidosis with a highly-significant difference between survivors and non-survivors. PH and HCO3 values were significantly lower in non-survivors than those in the survivor group. Furthermore, SaO2 value was significantly higher in survivors than that of non-survivors. So the managing Alp-poisoning should be started for first 6hr since exposure. Treatment includes early gastric lavage with potassium-permanganate-(1:10,000), sodium-bicarbonate or coconut-oil/liquid-paraffin. The mechanism of Alp-poisoning explained that, phosphine gas inhibits 70% of mitochondrial cytochrome-c-oxidase in myocardial-tissue by the effect of free-radicals; electrolyte disturbance, and intracellular acidosis all cause a reduction in cardiac function, and multi-organ damage. These effects may cause arrhythmia and myocarditis which may be the cause of death. Conclusion It was concluded that myocardial depression with shock and metabolic acidosis may lead to respiratory failure due to acute Alp-poisoning. This case study reported that coconut oil play a pivotal role in managing acute Alp- poisoning even 6h post ingestion for reducing the oxidative outcomes of phosphine and recommended as antidote for acute Alp-intoxication.

Comparative study between volume-controlled ventilation and pressure-controlled ventilation in prevention of postoperative pulmonary atelectasis in morbidly obese patients undergoing laparoscopic gastric sleeve surgery

BackgroundAtelectasis can result during general anesthesia from mechanical ventilation and decrease in lung volume particularly in morbidly obese patients undergoing abdominal laparoscopic sleeve surgery, which may result in the development of postoperative pulmonary complications (PPCs), including hypoxemia and pneumonia, with an increased risk of postoperative morbidity and mortality.ObjectiveTo compare between volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) in prevention of postoperative pulmonary atelectasis in morbidly obese patients undergoing laparoscopic gastric sleeve surgery.MethodsThis is a randomized prospective comparative clinical study with a total of 52 morbidly obese patients who were randomly divided into 2 groups; 26 patients in group (V) for VCV and 26 in group (P) for PCV arterial blood samples were obtained, and PaCO2, PaO2, and SaO2 were obtained and recorded. ABG analyses were also obtained 30 min, 12 h, and 24 h post-extubation, and PaCO2, PaO2, and SaO2 were obtained and recorded.ResultsThe results of this study revealed no significant differences between PCV and VCV as regards the incidence of postoperative lung atelectasis immediately postoperative (69.2% with VCV vs 61.5% with PCV, p = 0.368), 12 h postoperative (61.5% with VCV vs 53.8% with PCV, p = 0.282), and 24 h postoperative (53.8% with VCV vs 46.2% with PCV, p = 0.325). There were also no significant differences between VCV and PCV as regards baseline, intra-, and post-operative PaCO2 levels as well as baseline and postoperative SaO2 and PaO2 values. However, PCV showed better intraoperative oxygenation compared to VCV. SaO2 was 96.32% ± 1.85 and 97.25% ± 1.37 in VCV and PCV groups respectively (p = 0.027) while PaO2 was 212.75 mmHg ± 20.13 and 225.8 mmHg ± 18.69 in VCV and PCV groups respectively (p = 0.011).ConclusionDespite a slight improvement in intraoperative oxygenation parameters (PO2, SaO2) with PCV than VCV, there is no significant difference between VCV and PCV in the prevention of postoperative pulmonary atelectasis; moreover, there is no difference in postoperative oxygenation parameters in morbidly obese patients who undergo laparoscopic sleeve surgery.

The Importance of Electrocardiography in Pediatric Patients with Pulmonary Arterial Hypertension in Follow- up

Background: Right Ventricular (RV) hypertrophy is an adaptive response to chronic RV pressure overload in patients with pulmonary hypertension. We investigated the relationships between RV hypertrophy indicators, including electrocardiography, the percentage oxygen saturation (SaO2%), body mass index (BMI), and blood uric acid levels in patients with a biventricular structure followed up for Pulmonary Arterial Hypertension (PAH). Materials and Methods: This retrospective study included 33 patients with confirmed systemic PAH, according to the catheterization and a negative vascular reactivity test result. Patients with single-ventricle physiology and Down’s syndrome who had undergone surgery were excluded. The data of blood chemistry, hemogram, ECG, and SaO2% were collected, thus, the BMI was calculated. The patients were categorized according to SaO2 values ( 90% [n=19]), BMI (18.5 [n=17] kg/m2), PAH status (primary [n=13] vs. secondary [n=20]), and treatment regime (combination therapy [n=16] vs. monotherapy [n=17]), and the data were compared among the groups. Results: Patients with SaO2 values of 90% differed only in terms of blood uric acid level, which was significantly higher in the patients with SaO2 9 mm indicating impaired capacity. These measured markers can be used to follow-up patients with PAH.

Does altitude affect blood gases in hemodialysis patients?

This study aimed to determine whether predialysis blood gases is affected by altitude differences in hemodialysis patients with arteriovenous fistulas living in Turkey at three different altitudes. Patients' predialysis blood gases were compared by standardizing both arterial blood gases collections and working methods for patients undergoing hemodialysis using a dialysate with the same properties at altitudes of 30 m (sea level), 1020 m (moderate altitude), and 1951 m (high altitude). Blood gases disorders were detected in 32 (82.1%) high altitude group patients, whereas 49 (74.2%) sea level group patients had no blood gases disorders (P < 0.001). pH values in the high altitude group were significantly lower than those in the other groups, and the pH increased as altitude decreased (P < 0.001). The partial pressure of carbon dioxide (PaCO2 ) values was higher in the sea level group than in the other groups and increased at lower sea levels (P < 0.001). Bicarbonate values were significantly higher in the sea level group than in the other groups and increased at lower sea levels, similar to PaCO2 values (P < 0.001). The partial pressure of oxygen (PaO2 ) values in the high altitude and sea level groups were significantly higher and increased at lower sea levels (P < 0.001). The oxygen saturation (SaO2 ) values were significantly lower in the high altitude group than in the other groups and increased gradually at lower sea levels (P < 0.001). Predialysis metabolic acidosis was more pronounced in patients undergoing hemodialysis at high altitudes, whereas PaCO2 , PaO2 , and SaO2 values were lower.

Retinal oxygen saturation and vessel diameter in patients with chronic kidney disease.

To investigate changes in retinal oximetry and the diameter of retinal vasculature in patients with chronic kidney disease (CKD) and relationships between retinal vasculature and the estimated glomerular filtration rate (eGFR), provide a scientific basis for the early detection and diagnosis of CKD. Eighty-three patients with CKD and 103 healthy individuals were included after providing informed consent. All participants were examined using a noninvasive technology (Oxymap Inc., Reykjavik, Iceland) for measuring the arterial (SaO2 ) and venous (SvO2 ) oxygen saturation and the arteriovenous difference in oxygen saturation (Sa-vO2 ). The corresponding retinal vessel diameters of these arterioles (D-A) and venules (D-V) were measured. The eGFR of patients with CKD was calculated from the serum creatinine concentration. In general, patients with CKD had higher mean SaO2 values than healthy individuals (100.15±4.68% versus 97.14±4.22%; p<0.001, mean±SD). The mean SaO2 in the superior temporal, superior nasal and inferior nasal quadrants significantly increased. There was no significant difference measured in the SvO2 when patients with CKD (63.66±5.29%) and healthy individuals (62.70±5.27%) were compared. The mean Sa-vO2 of the CKD group (36.49±4.98%) was increased compared with normal subjects (34.44±4.76%) (p=0.005). The retinal arteriole diameter was narrower in patients with CKD than in normal individuals (117.53±14.88μm versus 126.87±14.98μm; p<0.001, mean±SD), and the arteriovenous ratio was smaller than in normal individuals (0.71±0.09 versus 0.77±0.09; p<0.001, mean±SD). Pearson's two-tailed correlation showed a significant correlation between the SaO2 and eGFR (R=-0.363, p=0.001), and narrower retinal arterial calibre was significantly associated with a lower eGFR (R=0.415, p<0.001). Based on our results, there were alterations in retinal oxygen saturation and vascular diameter in patients with CKD. Further studies are needed to determine whether such changes play a role in the development of CKD.