Episodes Of Hypoxemia Research Articles

Association of response time and intermittent hypoxemia in extremely preterm infants.

To determine the relationship between medical staff's response time (RT) to oxygen saturation (SpO2 ) below 80% and the associated time from tactile intervention until SpO2 normalisation (CT). Time-lapse video and continuous SpO2 were recorded for six consecutive 24 h periods. Regression analyses of RT and SpO2 in association with postmenstrual age (PMA), weight, infant sex and frequency of intermittent hypoxemia (IH). Five hundred and twelve hypoxemia episodes received tactile intervention in 20 extremely preterm infants (gestational age ≤28 weeks, birthweight <1500 g). Median RT was 20.5 s (IQR 16.63-25.50). RT increased with increased IH frequency (p = 0.023) independently of PMA and weight. SpO2 decreased by 3.7% with every 10 s RT (p = 0.039). Time until SpO2 normalisation was strongly associated with RT (β = 0.58, p = 0.042). The association was amplified by lower PMA (p = 0.043). Female preterm infants experienced longer RT than males (p = 0.027). Because the total length of an IH is the sum of RT and CT, preterm infants with low PMA can reach a critical hypoxemia duration of >60 s, even with short RT. The RT is a critical factor that affects the overall time of IH treatments and the depth of desaturation. The consequences of a prolonged RT are worse for more immature preterm infants.

The use of High-Flow Nasal Oxygen Therapy in 4 dogs undergoing bronchoscopy.

High-Flow Nasal Oxygen Therapy is a method to deliver warmed, humidified air-oxygen blended at high flow rates to patients through a nasal cannula using a specialized, commercially available machine. This is a well-tolerated, safe and effective method for oxygen delivery to healthy and hypoxemic dogs. Patients undergoing bronchoscopic procedures frequently develop hypoxemia. Human trials have shown a reduction in incidents of hypoxemic events and higher pulse oximeter oxygen saturation during bronchoscopies in patients on High-Flow Nasal Oxygen. This is a single-centre, prospective case series. All dogs weighing between 5 and 15 kg and undergoing bronchoscopy during the study period (03/07/2022-01/10/2022) were eligible. Twelve patients were eligible for inclusion of which four were enrolled. No clinically significant complications related to the use of High-Flow Nasal Oxygen Therapy were recorded. Two of the patients were re-intubated post bronchoscopy due to clinician preference for recovery. One of the patients had a self-limiting period of severe hypoxemia with a pulse oximeter oxygen saturation of 84% for < 1 min during bronchoalveolar lavage, and whilst undergoing High-Flow Nasal Oxygen administration. Another patient had a self-limiting episode of mild hypoxemia (SpO2 of 94% lasting < 1 min) 5 min after completion of bronchoalveolar lavage. No clinically relevant complications relating to High-Flow Nasal Oxygen Therapy were recorded in this case series, although further studies are required to confirm this conclusion. This initial data suggests that the use of High-Flow Nasal Oxygen therapy during bronchoscopy is feasible and potentially safe, although it may not prevent hypoxemia in these patients. The use of High-Flow Nasal Oxygen Therapy during bronchoscopy in small patients carries multiple potential benefits and further studies to compare its efficacy against other traditional oxygen delivery systems are warranted in this patient population.

Late permissive hypercapnia and respiratory stability among very preterm infants: a pilot randomised trial

ObjectiveDetermine if targeting higher transcutaneous carbon dioxide improves respiratory stability among very preterm infants on ventilatory support.DesignSingle-centre pilot randomised clinical trial.SettingThe University of Alabama at Birmingham.PatientsVery preterm infants on ventilatory...

Perioperative Hypoxemia and Postoperative Respiratory Events in Infants with Hypertrophic Pyloric Stenosis.

Normalization of metabolic alkalosis is an important pillar in the treatment of infantile hypertrophic pyloric stenosis (IHPS) because uncorrected metabolic alkalosis may lead to perioperative respiratory events. However, the evidence on the incidence of respiratory events is limited. We aimed to study the incidence of peroperative hypoxemia and postoperative respiratory events in infants undergoing pyloromyotomy and the potential role of metabolic alkalosis. We retrospectively reviewed all patients undergoing pyloromyotomy between 2007 and 2017. All infants received intravenous fluids preoperatively to correct metabolic abnormalities close to normal. We assessed the incidence of perioperative hypoxemia (defined as oxygen saturation [SpO2] < 90% for > 1min) and postoperative respiratory events. Additionally, the incidence of difficult intubations was evaluated. We performed a multivariate logistic regression analysis to evaluate the association between admission or preoperative serum pH values, bicarbonate or chloride, and peri- and postoperative hypoxemia or respiratory events. Of 406 included infants, 208 (51%) developed 1 or more episodes of hypoxemia during the perioperative period, of whom 130 (32%) experienced it during induction, 43 (11%) intraoperatively, and 112 (28%) during emergence. About 7.5% of the infants had a difficult intubation and 17 required more than 3 attempts by a pediatric anesthesiologist. Three patients developed respiratory insufficiency and 95 postoperative respiratory events were noticed. We did not find a clinically meaningful association between laboratory values reflecting metabolic alkalosis and respiratory events. IHPS frequently leads to peri- and postoperative hypoxemia or respiratory events and high incidence of difficult tracheal intubations. Preoperative pH, bicarbonate, and chloride were bad predictors of respiratory events.

Comparison of oxygen supplementation in very preterm infants: Variations of oxygen saturation features and their application to hypoxemic episode based risk stratification.

Oxygen supplementation is commonly used to maintain oxygen saturation (SpO2) levels in preterm infants within target ranges to reduce intermittent hypoxemic (IH) events, which are associated with short- and long-term morbidities. There is not much information available about differences in oxygenation patterns in infants undergoing such supplementations nor their relation to observed IH events. This study aimed to describe oxygenation characteristics during two types of supplementation by studying SpO2 signal features and assess their performance in hypoxemia risk screening during NICU monitoring. SpO2 data from 25 infants with gestational age <32 weeks and birthweight <2,000 g who underwent a cross over trial of low-flow nasal cannula (NC) and digitally-set servo-controlled oxygen environment (OE) supplementations was considered in this secondary analysis. Features pertaining to signal distribution, variability and complexity were estimated and analyzed for differences between the supplementations. Univariate and regularized multivariate logistic regression was applied to identify relevant features and develop screening models for infants likely to experience a critically high number of IH per day of observation. Their performance was assessed using area under receiver operating curves (AUROC), accuracy, sensitivity, specificity and F1 scores. While most SpO2 measures remained comparable during both supplementations, signal irregularity and complexity were elevated while on OE, pointing to more volatility in oxygen saturation during this supplementation mode. In addition, SpO2 variability measures exhibited early prognostic value in discriminating infants at higher risk of critically many IH events. Poincare plot variability at lag 1 had AUROC of 0.82, 0.86, 0.89 compared to 0.63, 0.75, 0.81 for the IH number, a clinical parameter at observation times of 30 min, 1 and 2 h, respectively. Multivariate models with two features exhibited validation AUROC > 0.80, F1 score > 0.60 and specificity >0.85 at observation times ≥ 1 h. Finally, we proposed a framework for risk stratification of infants using a cumulative risk score for continuous monitoring. Analysis of oxygen saturation signal routinely collected in the NICU, may have extensive applications in inferring subtle changes to cardiorespiratory dynamics under various conditions as well as in informing clinical decisions about infant care.

Rearrangement of cell types in the rat carotid body neurogenic niche induced by chronic intermittent hypoxia.

The carotid body (CB) is a prototypical acute oxygen (O2 )-sensing organ that mediates reflex hyperventilation and increased cardiac output in response to hypoxaemia. CB overactivation, secondary to the repeated stimulation produced by the recurrent episodes of intermittent hypoxia, is believed to contribute to the pathogenesis of sympathetic hyperactivity present in sleep apnoea patients. Although CB functional plasticity induced by chronic intermittent hypoxia (CIH) has been demonstrated, the underlying mechanisms are not fully elucidated. Here, we show that CIH induces a small increase in CB volume and rearrangement of cell types in the CB, characterized by a mobilization of immature quiescent neuroblasts, which enter a process of differentiation into mature, O2 -sensing and neuron-like, chemoreceptor glomus cells. Prospective isolation of individual cell classes has allowed us to show that maturation of CB neuroblasts is paralleled by an upregulation in the expression of specific glomus cell genes involved in acute O2 -sensing. CIH enhances mitochondrial responsiveness to hypoxia in maturing neuroblasts as well as in glomus cells. These data provide novel perspectives on the pathogenesis of CB-mediated sympathetic overflow that may lead to the development of new pharmacological strategies of potential applicability in sleep apnoea patients. KEY POINTS: Obstructive sleep apnoea is a frequent condition in the human population that predisposes to severe cardiovascular and metabolic alterations. Activation of the carotid body, the main arterial oxygen-sensing chemoreceptor, by repeated episodes of hypoxaemia induces exacerbation of the carotid body-mediated chemoreflex and contributes to sympathetic overflow characteristic of sleep apnoea patients. In rats, chronic intermittent hypoxaemia induces fast neurogenesis in the carotid body with rapid activation of neuroblasts, which enter a process of proliferation and maturation into O2 -sensing chemoreceptor glomus cells. Maturing carotid body neuroblasts and glomus cells exposed to chronic intermittent hypoxia upregulate genes involved in acute O2 sensing and enhance mitochondrial responsiveness to hypoxia. These findings provide novel perspectives on the pathogenesis of carotid body-mediated sympathetic hyperactivation. Pharmacological modulation of carotid body fast neurogenesis could help to ameliorate the deleterious effects of chronic intermittent hypoxaemia in sleep apnoea patients.

Opioid Reduced Anesthesia in Major Oncologic Cervicofacial Surgery: A Retrospective Study.

This is a retrospective case-controlled study of 172 patients with major cervicofacial oncologic surgery. Group ORA (dexmedetomidine and lidocaine), n = 86, was compared to patients treated with standard opioid based anesthesia, Group control, n = 86. The main endpoint was to study perioperative opioid consumption and postoperative pain scores, and the secondary endpoint was to observe opioid related side effects. The ORA group received 6.2 ± 3.1 mg morphine titration at the end of surgery, while the control group received 10.1 ± 3.7 mg p < 0.0001; there was no significant difference in post-operative analgesia requirements and pain scores between the groups. Intraoperatively, the ORA protocol yielded bradycardia in 4 persons, while in the control group, only 2 persons had bradycardia necessitating intervention, p < 0.05. Postoperatively, episodes of hypoxemia (50%) and the need for additional pressure-assisted ventilation (6%), was significantly different in the ORA group than in the control group (70% and 19%), p < 0.05. There was no difference between the two groups for the incidence of nausea and vomiting, ileus, or postoperative delirium. ORA was not associated with a decrease in postoperative pain and opioid requirement, but possibly reduced the incidence of hypoxemia and the use of additional pressure-assisted ventilation, although we cannot rule out confounding factors. The possible benefits of ORA remain to be demonstrated by prospective studies.

Anesthetic Management in a Case of Rett Syndrome: A Case Report

Rett syndrome (RS) is a progressive neurological disorder that almost exclusively affects females. It is characterized by severe mental retardation following a period of normal development during childhood. Classical features include autism, stereotypical hand movements, seizures, microcephaly and abnormal respiratory control. Anesthetic challenges in patients with RS include difficult airway, seizure management, positioning, increased sensitivity to sedatives, autonomic dysfunction, anesthesia-triggered episodes of apnoea, hypoxemia and sudden death. Here, we describe the successful anesthetic management of a 13-year-old patient with RS exhibiting most of these features who underwent laparoscopic SOS open ovarian cystectomy and hysterectomy.

Hypoxemia and not hyperoxemia predicts worse outcome in severe COPD exacerbations - an observational study

ABSTRACT Objectives For patients admitted with an acute exacerbation of COPD (AECOPD) and a need for supplementary oxygen therapy, to determine if peripheral oxygen saturation < 88% (hypoxemia) or >92% (hyperoxemia), within first 24 hours of admission, is associated with ‘treatment failure’ or fewer days alive and out of hospital within 14 days after admission. Design A retrospective multicenter observational study, reviewing consecutive data on SpO2, oxygen, and drug administration at three predefined time points, on adverse events in patients admitted with COPD between December 2019 and June 2020. Multivariable logistic regression analysis, Mann Whitney U- and Chi-square-test were used. Setting Acute hospital setting, across four different hospitals in the capital region of Denmark. Participants Patients with a confirmed diagnosis of COPD admitted with an acute exacerbation and an oxygen need within the first 24 hours admission. Results In total 289 COPD patients were included. The median age was 74.8 years [interquartile range (IQR):69.6 to 81.8], 191 were female and 132 patients experienced ‘treatment failure’. A minimum of one episode of hypoxemia (SpO2 < 88%) within first 24 hours was associated with having a low number (≤4) of days alive and out of hospital within 14 days after admission: OR 2.4 (95%CI 1.2 to 4.8), p = 0.02, absolute risk 44% vs. 26% p = 0.01, Chi-square. Comparable results were observed after 30 days of follow-up: OR 2.6 (95% CI 1.0 to7.1), p = 0.05. A minimum of one measurement of hyperoxemia (SpO2 > 92%), within first 24 hours of admission was not associated with low number of days alive and out of hospital within 14 days OR 1.0 (95% CI 0.5 to 2.1) nor at 30 days. Conclusion For admitted patients with AECOPD, being hypoxemic ever within the first 24 hours after admission is associated with a substantially increased risk of a poor prognosis.

Closed-loop oxygen control for patients with hypoxaemia during hospitalisation: a living systematic review and meta-analysis protocol

IntroductionOxygen is the most common drug used in critical care patients to correct episodes of hypoxaemia. The adoption of new technologies in clinical practice, such as closed-loop systems for an...

Transpyloric Feeding is Associated With Improved Oxygenation Compared With Gastric Feeding Among Nonintubated Extremely Low Birth Weight Infants

To study the impact of transpyloric (TP) feed initiation on short-term oxygenation and manual oxygen blender titration among extremely low birth weight infants. This retrospective study evaluated several measures of oxygenation among extremely low birth weight infants receiving positive pressure respiratory support for 96hours before and after TP tube placement in a single neonatal intensive care unit during the years 2017- 2020. The measures included the achieved oxygen saturation (SpO2), the baseline fraction of inspired oxygen (FiO2), the SpO2/FiO2 ratio, the number and severity of hypoxemic episodes and the frequency of manual oxygen titrations (titration index) and were analyzed using an interrupted time series regression approach. A total of 56 infants were evaluated. No significant differences were observed in any oxygenation measures during TP vs gastric feeding among 14 intubated infants. However, among 42 nonintubated patients, significant improvements were observed in the median SpO2/FiO2 ratios (P=.001), median titration index (P=.05), median number of hypoxemic episodes (P=.02), and median severity of hypoxemic episodes (P=.008) after TP tube placement. The transition from gastric to TP tube feeding was temporally associated with acute improvement in oxygenation for nonintubated infants, but not for intubated infants.

Closed-loop automated oxygen control in ventilated infants born at or near term: A crossover trial.

To determine if the use of closed-loop automated oxygen control (CLAC) reduced the incidence and duration of hypoxemic episodes (SpO2 < 92%) in ventilated infants born at or above 34 weeks of gestation. Infants were studied on two consecutive days for 6 h each day. They were randomised to receive standard care (manual oxygen control) or standard care with a CLAC system (automated oxygen control) first. Sixteen infants with a median (IQR) gestational age of 37.4 (36.6-38.8) weeks were studied at a median (IQR) postmenstrual age of 38.8 (37.4-39.8) weeks. During the automated oxygen control period, infants spent less time in hypoxemia (SpO2 < 92%) (p= 0.033), episodes of desaturation were shorter (p= 0.001), the time spent within target SpO2 range (92%-96%) was increased (p= 0.001), and the FiO2 delivery was lower (p= 0.018). The time spent in hyperoxemia (SpO2 > 96%) was reduced during automated oxygen control (p= 0.011), the episodes of hyperoxemia were of shorter duration (p= 0.008) and fewer manual adjustments were made to the FiO2 (p= 0.005). Closed-loop automated oxygen control in ventilated infants born at or near term was associated with a reduction in the incidence and duration of hypoxemic episodes with more time spent in the target oxygen range.

Experimental Models to Study End-Organ Morbidity in Sleep Apnea: Lessons Learned and Future Directions.

Sleep apnea (SA) is a very prevalent sleep breathing disorder mainly characterized by intermittent hypoxemia and sleep fragmentation, with ensuing systemic inflammation, oxidative stress, and immune deregulation. These perturbations promote the risk of end-organ morbidity, such that SA patients are at increased risk of cardiovascular, neurocognitive, metabolic and malignant disorders. Investigating the potential mechanisms underlying SA-induced end-organ dysfunction requires the use of comprehensive experimental models at the cell, animal and human levels. This review is primarily focused on the experimental models employed to date in the study of the consequences of SA and tackles 3 different approaches. First, cell culture systems whereby controlled patterns of intermittent hypoxia cycling fast enough to mimic the rates of episodic hypoxemia experienced by patients with SA. Second, animal models consisting of implementing realistic upper airway obstruction patterns, intermittent hypoxia, or sleep fragmentation such as to reproduce the noxious events characterizing SA. Finally, human SA models, which consist either in subjecting healthy volunteers to intermittent hypoxia or sleep fragmentation, or alternatively applying oxygen supplementation or temporary nasal pressure therapy withdrawal to SA patients. The advantages, limitations, and potential improvements of these models along with some of their pertinent findings are reviewed.

Oxygen targets and 6-month outcome after out of hospital cardiac arrest: a pre-planned sub-analysis of the targeted hypothermia versus targeted normothermia after Out-of-Hospital Cardiac Arrest (TTM2) trial

BackgroundOptimal oxygen targets in patients resuscitated after cardiac arrest are uncertain. The primary aim of this study was to describe the values of partial pressure of oxygen values (PaO2) and the episodes of hypoxemia and hyperoxemia occurring within the first 72 h of mechanical ventilation in out of hospital cardiac arrest (OHCA) patients. The secondary aim was to evaluate the association of PaO2 with patients’ outcome.MethodsPreplanned secondary analysis of the targeted hypothermia versus targeted normothermia after OHCA (TTM2) trial. Arterial blood gases values were collected from randomization every 4 h for the first 32 h, and then, every 8 h until day 3. Hypoxemia was defined as PaO2 < 60 mmHg and severe hyperoxemia as PaO2 > 300 mmHg. Mortality and poor neurological outcome (defined according to modified Rankin scale) were collected at 6 months.Results1418 patients were included in the analysis. The mean age was 64 ± 14 years, and 292 patients (20.6%) were female. 24.9% of patients had at least one episode of hypoxemia, and 7.6% of patients had at least one episode of severe hyperoxemia. Both hypoxemia and hyperoxemia were independently associated with 6-month mortality, but not with poor neurological outcome. The best cutoff point associated with 6-month mortality for hypoxemia was 69 mmHg (Risk Ratio, RR = 1.009, 95% CI 0.93–1.09), and for hyperoxemia was 195 mmHg (RR = 1.006, 95% CI 0.95–1.06). The time exposure, i.e., the area under the curve (PaO2-AUC), for hyperoxemia was significantly associated with mortality (p = 0.003).ConclusionsIn OHCA patients, both hypoxemia and hyperoxemia are associated with 6-months mortality, with an effect mediated by the timing exposure to high values of oxygen. Precise titration of oxygen levels should be considered in this group of patients.Trial registration: clinicaltrials.gov NCT02908308, Registered September 20, 2016.

Can intravenous lidocaine definitely attenuate propofol requirement and improve outcomes among colonoscopic patients under intravenous sedation?: A double-blinded, randomized controlled trial.

Background:Propofol-sparing effect of lidocaine has not been fully elucidated because propofol is usually mixed with many medications in anesthetic practice. Therefore, the study aimed to verify the additive effect of intravenous lidocaine to propofol without other sedative medications and control the depth of anesthesia using the bispectral index (BIS) during colonoscopy in a prospective, randomized, double-blinded controlled trial.Methods:Sixty-eight patients scheduled and undergoing colonoscopy were randomly allocated to receive intravenous lidocaine (1.5 mg/kg then 4 mg/kg/h) (Group L) or a similar volume of normal saline (Group C) with propofol administration guided by BIS monitoring. The primary outcome was total propofol requirements between group comparisons. The secondary outcomes included the number of hypoxemic periods, hemodynamic changes, duration in returning of BIS > 85, sedation scores, pain scores, postoperative opioid requirement, and patient satisfaction between group comparisons.Results:Intravenous lidocaine showed significantly reduced total propofol use (151.76 ± 50.78 mg vs 242.06 ± 50.86 mg, Group L vs Group C, respectively, P < .001). Duration in returning to BIS > 85, sedation scores, and patient satisfaction scores were significantly superior in Group L (P < .05). The number of hypoxemic episodes, changes of hemodynamic response, pain scores, and postoperative opioid requirement were similar in both groups. No adverse effects were detected in both groups.Conclusion:Intravenous lidocaine produced a definitely effective reduced propofol requirement without other sedative agents and improved outcomes including patient satisfaction, duration in returning to BIS > 85, and sedation score during colonoscopy without adverse effects.

Lung volume changes during apnoeas in preterm infants

ObjectiveMechanisms of non-invasive high-frequency oscillatory ventilation (nHFOV) in preterm infants are unclear. We aimed to compare lung volume changes during apnoeas in preterm infants on nHFOV and nasal continuous positive...

Effect of the Target Range on Arterial Oxygen Saturation Stability in Extremely Premature Infants

Objective: The aim of this study was to compare the effect of targeting arterial oxygen saturation (SpO2) in the high (93–95%) versus the low portion (90–92%) of the recommended range of 90–95% on oxygenation stability in extremely premature infants. Methods: Premature infants of ≤28 weeks of gestational age who received a fraction of inspired oxygen (FiO2) > 0.21 after day 14 were eligible. FiO2 was adjusted by a dedicated investigator to keep SpO2 between 90–92% and 93–95% for 2 h each in random sequence. Episodes of intermittent hypoxemia (IH) were defined as SpO2 <90% for ≥10 s; severe IH episodes were defined as SpO2 <80% for ≥10 s. Hyperoxemia was defined as SpO2 >95% or >98%. Results: Eighteen premature infants were enrolled. Their (mean ± SD) GA was 26 ± 1.5 w. Seven infants were on mechanical ventilation, 4 infants on nasal ventilation, and 7 infants on nasal cannula. They were on a mean FiO2 0.38 ± 0.12 at study entry. Episodes of IH and severe IH were more frequent during the low compared to the high target (36.6 [27.0–41.3] vs. 16.0 [7.8–19.0], p < 0.001; 8.4 ± 9.3 vs. 3.2 ± 4.3, p = 0.002). The proportions of time with SpO2 >95% and >98% were greater with the high target (13.9 ± 11 vs. 34.1 ± 15.4%, p < 0.001; 0.9 [0–5.7] vs. 3.4 [0.5–16.1]%, p = 0.002). Conclusion: In this group of extremely premature infants, targeting SpO2 at the lower portion of the recommended range resulted in more frequent episodes of IH. However, targeting the higher SpO2 range led to more hyperoxemia. This trade-off warrants further investigation.

Pulse oximetry reliability for detection of hypoxemia under motion in extremely premature infants.

Episodes of intermittent hypoxemia (IH) in extremely premature infants are detected by pulse oximetry (SpO2) but motion artifact can cause falsely low readings. To evaluate the reliability of SpO2 during IH episodes associated with motion in premature infants of ≤28 weeks GA monitored with 2 pulse oximeters. IH episodes (defined as SpO2 < 90%, >10 s and SpO2 < 80%, >10 s) were classified by an analytic tool based on distortion caused by motion in the pulse plethysmograph (Pleth) as: A (true hypoxemia), both SpO2 decreased (only one Pleth showed motion); B (false hypoxemia), one SpO2 decreased (Pleth showed motion) and the other didn't (Pleth didn't show motion); C (suspected hypoxemia), both SpO2 decreased (both Pleth showed motion); D (true hypoxemia-motion free), both SpO2 decreased (neither Pleth showed motion). In 24-72 h data from 20 infants of 25.4 ± 1.5 weeks GA, 14.1 ± 5.7 episodes with SpO2 < 90% and 7.9 ± 5.5 episodes with SpO2 < 80% per infant were identified. 29 ± 15% of episodes with SpO2 < 90% were type A, 1 ± 2% B, 43 ± 21% C and 27 ± 23% D, while 26 ± 22% of episodes with SpO2 < 80% were type A, 0.3 ± 1.2% B, 45 ± 29% C, and 19 ± 25% D [p < 0.001 type B vs. rest (GLM-repeated measures)]. In extremely premature infants SpO2 with motion artifact is more likely to indicate true- than false hypoxemia. Uncertainty on the effect of motion on SpO2 accuracy during hypoxemia episodes in premature infants can influence the caregiver's trust on SpO2 and influence their response. This study evaluated data from two pulse oximeters used simultaneously in different extremities to determine the reliability of SpO2 during motion artifact in premature infants. Data from this study showed that in extremely premature infants SpO2 is more likely to indicate true- than false hypoxemia during episodes of hypoxemia associated with motion artifact.

Robustness of Distinctive Facial Features in Prader-Willi Syndrome: A Stereophotogrammetric Analysis and Association with Clinical and Biochemical Markers in Adult Individuals.

Simple SummaryPrader-Willi syndrome (PWS) is a rare genetically determined neurodevelopmental disorder usually associated with a peculiar facial appearance. There is poor information concerning the relationships between the facial dysmorphism in PWS and other manifestations of the disease and its treatment. This exploratory study aimed to investigate this aspect, since this knowledge might aid in both diagnosis and monitoring of the disease. Three-dimensional facial images of fifteen Caucasian adult individuals with PWS were acquired through stereophotogrammetry; linear distances and angles were then calculated and compared with those of groups of healthy subjects matched for sex and age, obtained using the same noninvasive procedure. Individuals with PWS were evaluated for endocrine/metabolic dysfunction and nocturnal respiratory function, and their associations with facial features were tested. Some facial characteristics did not show any associations with other manifestations of PWS; therefore, they could constitute robust distinctive facial features and contribute to the diagnosis of the disorder. Conversely, other facial characteristics showed relationships with clinical and biochemical markers of PWS, suggesting their potentially useful role in the clinical monitoring and management of the disease. Further studies are needed to confirm these findings.Background: Prader-Willi syndrome (PWS) is a rare genomic imprinting disorder associated to a complex neurodevelopmental phenotype and a distinctive facial appearance. The study investigated the relationships between the quantitative facial dysmorphism in PWS and clinical and biochemical markers of the disease and its treatment. Methods: Facial images of 15 Caucasian adult individuals with PWS (8 males, 42 ± 5 years; 7 females, 37 ± 8 years; BMI 38.87 ± 8.92 kg/m2) were acquired through stereophotogrammetry. From the 3D coordinates of 38 landmarks, linear distances and angles were calculated; they were expressed as z-score values by referring to 403 healthy subjects matched for age and sex and compared by Student’s t-test with Bonferroni correction for multiple testing. Patients underwent auxological and biochemical assessment of endocrine/metabolic dysfunction and nocturnal respiratory function. An exploratory correlation analysis was performed to investigate their associations with the facial phenotype; uncorrected p-values were used. Results and Conclusions: Individuals with PWS showed decreased bifrontal diameter, facial depths, palpebral fissures, mandibular ramus length, lower vermillion height, and modified relative position of exocanthia and nasion. Since these characteristics did not show any associations with clinical and biochemical markers of PWS, they could constitute robust distinctive facial features and contribute to the diagnosis of the disorder. Individuals with PWS showed also a larger mandibular width with smaller gonial angles, thinner upper vermillion, greater inclination of the orbit relative to the Frankfurt plane, and a smaller angle of the auricles versus the facial midplane. Relationships between these facial anthropometric features and body composition, glucidic metabolism indexes, nocturnal hypoxemia episodes, or duration of GH treatment were found, suggesting their potentially useful role in the clinical monitoring and management of the disease. However, they need to be confirmed by subsequent dedicated studies.

Association between obstructive sleep apnea (OSA) and atrial fibrillation (AF): A dose-response meta-analysis.

Background:Refractory hypoxemia episodes are characteristic of obstructive sleep apnea (OSA). Patients with OSA suffer from oxidative stress in all systems. Atrial fibrillation (AF) is a type of arrhythmia that may be induced by OSA. In this study, we explored the dose-response relationship between OSA and AF. Our research provides the basis for a novel approach to AF prevention.Methods:We screened four databases (PubMed, Embase, the Cochrane Library, and Web of Science) for observational studies on OSA and AF. Studies were collected from database establishment to November 2020. We performed a traditional subgroup meta-analysis. Linear and spline dose-response models were applied to assess the association between the apnea-hypopnea index, an indicator of OSA severity, and the risk of AF. Review Manager version 5.3 software and Stata 16.0 were used for the analysis.Results:Sixteen observational studies were included in the study. We excluded a study from the conventional meta-analysis. In the subgroup analysis, the odds ratios for new onset AF for no obvious reason, new onset AF after surgical operations, such as coronary artery bypass grafting, and AF after ablation treatment were 1.71 (95% CI 1.37–2.13, P < .05), 2.65 (95% CI 2.32–3.01, P < .05), and 2.93 (95% CI 2.47–3.49, P < .05), respectively. Linear dose-response meta-analysis results revealed that the risk of AF increased with increasing apnea-hypopnea index value.Conclusion:Through dose-response meta-analysis, we found a potential dose-response relationship between OSA severity and the risk of AF. This relationship should be considered in interventions aimed at AF prevention in the future.