Nocturnal Pulse Oximetry Research Articles

Role of overnight oximetry in assessing the severity of obstructive sleep apnoea in typically developing children: a multicentre study

Background and objectiveCardiorespiratory polygraphy (CRP) is the predominant technology used to diagnose obstructive sleep apnoea (OSA) in tertiary centres in the UK. Nocturnal pulse oximetry (NPO) is, however, cheaper and...

Contribution of Transcutaneous PCO2 in Obesity Hypoventilation Syndrome.

More and more patients have obesity-hypoventilation syndrome (OHS) because of the increasing prevalence of obesity. The accuracy of transcutaneous PCO2 (PtcCO2 ) has recently been validated. However, no study evaluated the interest of measuring systematically nocturnal PtcCO2 in the follow-up of patients with OHS and home mechanical ventilation to detect residual nocturnal hypoventilation. We aimed to evaluate the contribution of nocturnal PtcCO2 to assess nocturnal hypoventilation compared with current routine examinations, that is, daytime arterial blood gases and nocturnal pulse oximetry. A prospective monocentric pilot study was conducted from August 2018 to November 2019. Patients with stable OHS and who were treated with home noninvasive ventilation for at least 6 months were eligible to participate. After oral consent, we performed both diurnal arterial blood gases and combined home oximetry and capnography. The primary end point was the presence of residual nocturnal hypoventilation, defined as PaCO2 > 45 mm Hg or bicarbonate ≥ 27 mmol/L, SpO2 < 90% for ≥ 10% of the night, or PtcCO2 > 49 mm Hg for ≥ 10% of the night. A total of 32 subjects were included. Twenty-nine subjects with nocturnal PtcCO2 were analyzed. Eighteen of the 29 subjects showed residual nocturnal hypoventilation. The association of diurnal arterial blood gases and nocturnal pulse oximetry revealed nocturnal hypoventilation in only 9 subjects. Among the 19 subjects with both normal blood gases and normal nocturnal pulse oximetry, 11 had nocturnal hypoventilation with transcutaneous capnography. Only one subject presented with hypoventilation symptoms (asthenia). The assessment of PtcCO2 in comparison with nocturnal pulse oximetry and arterial blood gases provides important information for the diagnosis of residual nocturnal hypoventilation in the subjects with OHS who were ventilated at home.

723 Nocturnal pulse oximetry studies before and after initiation of elexacaftor-tezacaftor-ivacaftor: retrospective review from a single cystic fibrosis center

723 Nocturnal pulse oximetry studies before and after initiation of elexacaftor-tezacaftor-ivacaftor: retrospective review from a single cystic fibrosis center

Longitudinal pilot study of oxygen saturation indices in healthy preterm infants

BackgroundThis study aimed to determine patterns of nocturnal pulse oximetry indices in moderate to late preterm infants, and investigate the relationship between oxygen desaturations, the apnoea hypopnoea index, and both corrected gestational and postnatal age.Methods21 healthy infants born at 32 + 0 - 36 + 6 weeks gestation underwent serial nocturnal pulse oximetry studies and respiratory polygraphy studies until 40 weeks corrected gestational age (CGA). The main outcome measures were number of >3% oxygen desaturations/hour (ODI3), mean oxygen saturations, and number of apnoeas and hypopnoeas/hour.ResultsMedian ODI3 increased between weeks 1 and 3 from 49.9 to 85.4/hour (p = 0.017). Mean oxygen saturations reached a corresponding nadir of 96.0% in week 3, then increased to 96.8% in week 6 (p = 0.019). Mixed effects modelling demonstrated that ODI3 and mean saturations were influenced by postnatal age but not CGA (p < 0.05). Desaturations frequently occurred without an apnoea or hypopnoea.ConclusionODI3 rises then falls during the first 8 weeks of life in moderate to late preterm infants, independently of CGA. These interesting preliminary results highlight the importance of further serial data collection to generate age-specific normal ranges, and develop a better understanding of respiratory control in preterm infants.ImpactThe frequency of >3% oxygen desaturations (ODI3) in healthy moderate to late preterm infants rises then falls after birth, peaking in postnatal week 3. There is a corresponding nadir in mean saturations.There were significant non-linear relationships between ODI3/mean saturations and postnatal age, but not corrected gestational age.The majority of brief oxygen desaturations occurred without an apnoea or hypopnoea.Normal ranges for oxygen saturation indices are not known in this population. These results demonstrate the need for further serial data collection to generate age-specific normal ranges and inform oxygen prescribing guidelines.

Interleukin 8 in children with obstructive sleep apnea before and after adenotonsillectomy

ObjectiveTo assess serum interleukin 8 (IL-8) levels after adenotonsillectomy in children with symptoms suggestive for OSA.Study designProspective interventional study.SettingsThe study was carried out on 30 children with OSA attending ENT clinic of Suez Canal University Hospital.MethodsIncluding, children with sleep-related chronic intermittent hypoxia (CIH) and OSA symptoms performed an elective adenotonsillectomy, and aged (3–12 years). Excluding, children with acute tonsillitis, cardiorespiratory, craniofacial, or diseases affecting IL-8 level as cystic fibrosis, COVID-19 patients, and hepatitis C, taking drugs affecting IL-8 level as benzodiazepines or glutamine supplementation. Children were subjected to full history, clinical examination and laboratory investigations. Nocturnal pulse oximetry (ChoiceMMed) was performed (48–72 h preoperative and 3–4 weeks postoperative) used to determine the number of 4% dips in saturation from baseline, and the nadir saturation (nSAT). IL-8 was measured 1 month pre-operative and 1 month post-operative by flow cytometry using the Human Inflammatory Cytometric Bead Array kit.ResultsThe mean preoperative IL-8 (237.55 p/ml) and oxygen desaturation index (7.77%)cwere statistically significantly higher than mean postoperative IL-8 (207.98 p/ml) and oxygen desaturation index (2.90). The mean pre-operative SpO2 is 98.27 ranged (96.00–100.0%), while the mean postoperative SpO2 is 98.77 ranged (97.00–100.0%), with no statistically significant difference between them (p = 0.069). Preoperative IL-8 (p/ml), postoperative IL-8 (p/ml), and preoperative SpO2 (%) were found to be negatively correlated with IL-8 change.ConclusionIL-8 level significantly decreased after adenotonsillectomy in children with symptoms suggestive for OSA.

Overnight changes in uric acid, xanthine oxidoreductase and oxidative stress levels and their relationships with sleep-disordered breathing in patients with coronary artery disease.

Serum uric acid (UA) level is associated with the high cumulative incidence or prevalence of coronary artery disease (CAD), and hyperuricemia is considered as an independent risk marker for CAD. Sleep-disordered breathing (SDB) is also associated with an increased risk of CAD. Several studies have shown that SDB is associated with hyperuricemia, but the mechanisms are unclear. We measured serum levels of UA and xanthine oxidoreductase (XOR) activity and urinary levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), all of which were assessed at 6 p.m. and the following 6 a.m. in males with CAD. In addition, nocturnal pulse oximetry was performed for the night. Overall 32 eligible patients with CAD were enrolled. Serum UA levels significantly increased overnight. (5.32 ± 0.98 mg/dl to 5.46 ± 1.02 mg/dl, p < 0.001) Moreover, XOR activity and urinary 8-OHdG levels significantly increased from 6 p.m. to 6 a.m. Furthermore, 3% Oxygen desaturation index (ODI) was correlated with the overnight changes in XOR activity (r = 0.36, P = 0.047) and urinary 8-OHdG levels (r = 0.41, P = 0.02). In addition, 3%ODI was independently correlated with the changes in XOR activity (correlation coefficient, 0.36; P = 0.047) and 8-OHdG (partial correlation coefficient, 0.63; P = 0.004) in multivariable analyses. SDB severity was associated with the overnight changes in XOR activity and urinary 8-OHdG, suggesting that SDB may be associated with oxidative stress via UA production. This trial is registered at University Hospital Medical Information Network (UMIN), number: UMIN000021624.

Sleep apnea in school-age children living at high altitude

IntroductionAmong adults, sleep apnea is more common in highlanders than in lowlanders. We evaluated the sleep apnea prevalence in children living at high altitude compared to age-matched low-altitude controls. MethodsHealthy children, 7-14 y of age, living at 2500-3800m in the Tien Shan mountains, Kyrgyzstan, were prospectively studied in a health post at 3250m. Healthy controls of similar age living at 700-800m were studied in a University Hospital at 760m in Bishkek. Assessments included respiratory sleep studies scored according to pediatric standards, clinical examination, medical history, and the pediatric sleep questionnaire (PSQ, range 0 to 1 with increasing symptoms). ResultsIn children living at high altitude (n = 37, 17 girls, median [quartiles] age 10.8y [9.6;13.0]), sleep studies revealed: mean nocturnal pulse oximetry 90% (89;91), oxygen desaturation index (ODI, >3% dips in pulse oximetry) 4.3/h (2.5;6.7), apnea/hypopnea index (AHI) total 1.7/h (1.0;3.6), central 1.6/h (1.0;3.3), PSQ 0.27 (0.18;0.45). In low-altitude controls (n=41, 17 girls, age 11.6y [9.5;13.0], between-groups comparison of age P=0.69) sleep studies revealed: pulse oximetry 97% (96;97), ODI 0.7/h (0.2;1.2), AHI total 0.4/h (0.1;1.0), central 0.3/h (0.1;0.7), PSQ 0.18 (0.14;0.31); P<0.05, all corresponding between-group comparisons. ConclusionsIn school-age children living at high altitude, nocturnal oxygen saturation was lower, and the total and central AHI were higher compared to children living at low altitude. The greater score of sleep symptoms in children residing at high altitude suggests a potential clinical relevance of the nocturnal hypoxemia and subtle sleep-related breathing disturbances.

Novel Indices to Improve the Diagnostic Ability of Nocturnal Oximetry in Children with OSAS

Nocturnal pulse oximetry (NOx) is an alternative diagnostic test for obstructive sleep apnea syndrome (OSAS) in childhood yet with variable diagnostic performance. Our aim was to apply advanced signal analysis to develop novel and more accurate NOx indices. We studied 45 children aged 3-10 years who underwent adenotonsillectomy for adenotonsillar hypertrophy and OSAS symptoms. Participants performed NOx before and three months after surgery, and the changes in McGill oximetry score (MOS), oxygen desaturation ≥3% index (ODI3), and the novel parameters-cumulative saturation area (CSA) and oxygen saturation sample entropy (SSE)-were assessed. There was a significant improvement (p < 0.001) in all NOx indices. When pre- and post-adenotonsillectomy NOx recordings were compared, the MOS had an area under the curve (AUC) of 0.811 with 63.2% sensitivity and 100% specificity at a cutoff >1. The AUC of ODI3 was 0.994, with 97.8% sensitivity and 91.1% specificity at a cutoff of >3.6 events per hour. The CSA and SSE had an AUC of 1.00, with 100% sensitivity and specificity at a cutoff of >293 and >0.99, respectively. We conclude that the herein-introduced indices-CSA and SSE-hold promise in improving the diagnostic ability of NOx in children suspected of OSAS.

No Difference in Sleep Desaturations Severity between Patients with Wake-Up and Non-Wake-Up Stroke: A PRESS Study Results.

Wake-up stroke (WUS) is a certain type of ischemic stroke in which a patient wakes up with a new neurological deficit due to cerebral ischemia. Sleep-disordered breathing is an independent risk factor for stroke, but the role of nocturnal oxygen desaturation in the pathophysiology of WUS is still insufficiently explored. According to several studies, patients with WUS have a significantly more severe sleep apnea syndrome and lower mean blood oxygen saturation. This study aimed to assess the severity of nocturnal desaturations in acute WUS and non-WUS patients using nocturnal pulse oximetry. The cohort of 225 consecutive patients with neuroimaging-verified acute cerebral ischemia was prospectively enrolled. For further analyses, 213 subjects with known WUS/non-WUS status were selected (111 males and 102 females, average age 70.4 ±12.9, median baseline NIHSS = 5, median baseline mRS = 3). Patients were divided into the WUS group (n = 45) and the non-WUS group (n = 168). Overnight pulse oximetry was performed within 7 days of the stroke onset and data of both of the studied groups were compared. We found oxygen desaturation index (ODI) in the WUS group was 14.5 vs. 16.6 (p = 0.728) in the non-WUS group, basal O2 saturation was 92.2% vs. 92.5% (p = 0.475), average low O2 saturation was 90.3% vs. 89.6% (p = 0.375), minimal O2 saturation was 79.5% vs. 80.6% (p = 0.563), and time with O2 saturation <90% (T90) was 4.4% vs. 4.7% (p = 0.729). In the studied sample, monitored respiratory parameters including ODI, basal O2 saturation, average low O2 saturation, minimal O2 saturation, and T90 did not significantly differ between groups of WUS and non-WUS patients.

Effect of Respiratory Events on Health-Related Quality of Life in Patients Treated with Long-Term Noninvasive Ventilation

Background: Long-term noninvasive ventilation (NIV) can increase or maintain health-related quality of life (HRQoL) for patients with chronic hypercapnic respiratory failure (CHRF). Evidence from studies systematically assessing how NIV-specific factors influence HRQoL is limited. Objectives: The objective of this study was to describe HRQoL measured by the Severe Respiratory Insufficiency Questionnaire (SRI) in patients with CHRF treated with long-term NIV and to analyze the associations between HRQoL and hypoxemia, hypercapnia, and respiratory events such as apneas, hypopneas (AHI), and patient ventilator asynchrony (PVA) occurring during long-term NIV. Methods: We included sixty-seven stable patients with established long-term NIV due to neuromuscular disease or thoracic cage disorders in a prospective cross-sectional study at Oslo University Hospital. Patients answered the SRI and underwent daytime arterial blood gases, nocturnal pulse oximetry, sleep polygraphy, and nocturnal transcutaneous CO₂. Results: The mean global SRI for 62 patients was 64.8 ± 14.5, with the highest score in SRI Social Relationships (79.5 ± 15.6). There were no differences in HRQoL between the different patient groups. Compliant patients had a significantly higher score in SRI Attendant and Sleep. Residual nocturnal hypoxemia affected both the subscale SRI “Respiratory Complaints” and SRI “Attendant Symptoms and Sleep.” Persisting daytime hypercapnia, nocturnal hypoventilation, and high AHI affected the subscale SRI “Anxiety” negatively, while frequent PVA was associated with a lower score in SRI “Physical Function.” Conclusion: In a group of patients with long-term NIV, undesired respiratory events during NIV are associated with lower HRQoL in several of the SRI subscales. We suggest designing interventional studies to confirm the possible relationship between HRQoL and respiratory events during long-term NIV.

Monitoring Long Term Noninvasive Ventilation: Benefits, Caveats and Perspectives.

Long term noninvasive ventilation (LTNIV) is a recognized treatment for chronic hypercapnic respiratory failure (CHRF). COPD, obesity-hypoventilation syndrome, neuromuscular disorders, various restrictive disorders, and patients with sleep-disordered breathing are the major groups concerned. The purpose of this narrative review is to summarize current knowledge in the field of monitoring during home ventilation. LTNIV improves symptoms related to CHRF, diurnal and nocturnal blood gases, survival, and health-related quality of life. Initially, patients with LTNIV were most often followed through elective short in-hospital stays to ensure patient comfort, correction of daytime blood gases and nocturnal oxygenation, and control of nocturnal respiratory events. Because of the widespread use of LTNIV, elective in-hospital monitoring has become logistically problematic, time consuming, and costly. LTNIV devices presently have a built-in software which records compliance, leaks, tidal volume, minute ventilation, cycles triggered and cycled by the patient and provides detailed pressure and flow curves. Although the engineering behind this information is remarkable, the quality and reliability of certain signals may vary. Interpretation of the curves provided requires a certain level of training. Coupling ventilator software with nocturnal pulse oximetry or transcutaneous capnography performed at the patient's home can however provide important information and allow adjustments of ventilator settings thus potentially avoiding hospital admissions. Strategies have been described to combine different tools for optimal detection of an inefficient ventilation. Recent devices also allow adapting certain parameters at a distance (pressure support, expiratory positive airway pressure, back-up respiratory rate), thus allowing progressive changes in these settings for increased patient comfort and tolerance, and reducing the requirement for in-hospital titration. Because we live in a connected world, analyzing large groups of patients through treatment of “big data” will probably improve our knowledge of clinical pathways of our patients, and factors associated with treatment success or failure, adherence and efficacy. This approach provides a useful add-on to randomized controlled studies and allows generating hypotheses for better management of HMV.

Nocturnal pulse oximetry as a possible screening method for obstructive sleep apnea in infants with laryngomalacia

ObjectiveLaryngomalacia can be an important cause of obstructive sleep apnea (OSA) in infants. Nocturnal oximetry is a cheap and safe method in comparison to polysomnography for the detection of sleep-disordered breathing. The aim of this study is to evaluate the validity of nocturnal oximetry as a diagnostic tool for OSA in infants with laryngomalacia. MethodsThis retrospective study included infants with laryngomalacia and a clinical suspicion of OSA who underwent a polysomnography at the Antwerp University Hospital. The oximetry was rescored manually, blinded to the polysomnography results, according to four different scoring methods. An obstructive apnea–hypopnea index (oAHI) ≥ 2/h on polysomnography was used to define OSA. ResultsThis study included 53 patients with laryngomalacia (51% boys, mean age 3.72 ± 0.26 months). A diagnosis of OSA was established in 46 patients (87%) by polysomnography. Among the four different scoring methods, the scoring according to Brouillette et al., yielded the highest diagnostic accuracy with a sensitivity and specificity of 91% and 25% respectively and with a negative and positive predictive value of 25% and 91%, respectively. Correlations and the Bland–Altman plot showed a wide limit of agreement for laboratory polysomnography oAHI and nocturnal oximetry ODI. ConclusionOur data show that overnight pulse oximetry has a high sensitivity and PPV to diagnose OSA in infants with laryngomalacia. However, the low specificity and NPV indicate that PSG is still needed to exclude OSA in cases with normal oximetry.

Diagnosis and correction of the obstructive sleep apnea syndrome in children with tonsillar ring pathological conditions

To summarize the results of a study of the clinical and polygrapic features of sleep in children with pathologic conditions of the tonsillar ring and obstructive sleep apnea. Tonsillar hypertrophy is the most common cause of obstructive sleep apnea in children. Using the data of overnight polysomnographic study and/or nocturnal pulse oximetry, groups of patients were distinguished depending on the presence and severity of their sleep breathing disorders. The effectiveness of adenotomy, adenotonsillotomy and/or adenotonsillectomy in children is demonstrated, depending on the severity of obstructive sleep apnea syndrome. Evaluation of breathing in sleeping children by polygraphic methods is necessary for early detection of obstructive sleep apnea syndrome and monitoring the effectiveness of surgical treatment.

Sleep-disordered breathing is independently associated with elevated natriuretic peptide levels in patients with cardiovascular diseases

Sleep disorders and sleep duration have attracted considerable attention as potential modifiable risk factors for the development and progression of heart failure (HF). However, whether these sleep behaviors could aggravate the underlying cardiac condition remains ambiguous. We evaluated the associations between the levels of plasma B-type natriuretic peptide (BNP) and sleep-disordered breathing (SDB), sleep quality and quantity, or daytime sleepiness in cardiovascular diseases (CVD) patients. A total of 1717 consecutive patients with CVD [median age, 66years (55-74years); female, 27.5%] were enrolled. SDB was screened by nocturnal pulse oximetry; sleep quality and quantity were determined by Pittsburg Sleep Quality Index, and daytime sleepiness was examined by Epworth Sleepiness Scale. The median plasma BNP level was 54.9pg/ml (23.5-146.4pg/ml). Multiple regression analyses showed that the BNP level in the highest quintile (BNP > 181.8pg/ml) was associated with SDB (severe: OR, 5.88; 95% CI 3.17-10.88; moderate: OR, 3.62; 95% CI 2.17-6.02; mild: OR, 2.22: 95% CI 1.42-3.47). There were no significant associations between other sleep parameters and higher BNP levels. The relationship between SDB and BNP levels was unchanged regardless of the previous history of symptomatic HF. SDB was independently associated with the elevated plasma BNP level in patients with a variety of CVD.

Observational study to define reference ranges for the 3% oxygen desaturation index during sleep in healthy children under 12 years using oximetry motion-resistant technology

ObjectiveTo define reference ranges for the 3% oxygen desaturation index (DI3) in healthy children under 12 years old during sleep.DesignObservational.SettingHome.SubjectsHealthy children aged 6 months to 12 years of age.InterventionNocturnal pulse...

822 Apnea every 5 minutes

Abstract Introduction Vagal Nerve Stimulators (VNS) are used in refractory epilepsy and depression. VNS are known to decrease airflow, oxygen saturation, and respiratory amplitude during sleep. We present a case of VNS induced OSA that was overlooked for 6 years. Report of case(s) A 63-year-old Caucasian female with refractory depression, hypothyroidism, and obesity presented with snoring and excessive daytime sleepiness (EDS). She had VNS implanted in a research trial for depression. She was on bupropion, duloxetine, lithium carbonate, lamotrigine, olanzapine, and levothyroxine. Polysomnography (PSG) showed moderate OSA with apnea-hypopnea index (AHI) of 25.8 and SpO2 nadir of 83%, and was titrated to bi-level positive airway pressure (PAP). She tried different masks and pressures but her leak and PAP intolerance persisted. There was no improvement in her EDS, and Armodafinil was prescribed for wake promotion. She struggled with bi-level PAP therapy for five years before being considered for hypoglossal nerve stimulator. But was turned down because of VNS presence. She was then recommended maxillomandibular advancement (MMA) but decided against it. She continued PAP therapy until a repeat PSG revealed mild to moderate OSA (AHI 10.9, RDI 17.8, and SpO2 nadir 79%), and it was noted that most of her respiratory events appeared in a regular fashion at 300-second intervals corresponding with the firing of VNS. PSG performed with VNS turned off showed no OSA (AHI 0.8 and SpO2 nadir 85%). PAP therapy was discontinued and subsequent nocturnal pulse oximetry showed normal oxygenation (ODI 15, RDI 17.8, SpO2 &amp;lt;88% for only 1.7 minutes). Her EDS resolved and VNS was eventually removed as per patient’s preference. She was started on a new medical therapy for depression. She continues to be asymptomatic. Conclusion Ascertainment bias led to delay in recognition of the cause of OSA as focus was on treatment only. Lowering the VNS frequency, increasing cycle time, turning it off during sleep or removal can improve respiratory events. The decision to do so depends on perceived benefit and harm of continuing VNS therapy. This case highlights the importance of re-evaluation of causes and treatment strategies when the standard of care is ineffective. Support (if any):

Effects of nocturnal complete denture usage on cardiorespiratory parameters: A pilot study

Statement of problemSleeping without conventional complete dentures (CCDs) has been stated by some to induce negative effects on the cardiorespiratory functions of edentulous patients with obstructive sleep apnea (OSA), although others have reported the exact opposite. Therefore, a consensus on nocturnal CCD usage is lacking. PurposeThe purpose of this clinical study was to assess the effects of nocturnal denture usage on cardiorespiratory stability by using pulse oximetry (PO). Materials and methodsThirty CCD wearers were enrolled in the study. The first nocturnal pulse oximetry (FNPO) recordings were made on 3 different nights while the participants were sleeping without dentures (WOD). Oxygen desaturation index (ODI) and other PO parameters of the participants, including total respiratory event (TRE), basal SpO2 (BSpO2), time≤88 (T88), average low SpO2 (ALSpO2), total pulse event (TPE), average pulse rate (APR), and heart rate variability index (HRVI), were processed and the obtained data were recorded as WOD condition values. According to the ODI scores, the OSA status of the participants was grouped as normal (ODI<5), mild (5<ODI<15), moderate (15<ODI<30), or severe (ODI>30). Complete dentures were fabricated by an experienced prosthodontist and a dental laboratory technician by following conventional procedures. At the end of the first month of the follow-up period, the second nocturnal PO recordings (SNPO) were made on 3 different nights while the participants slept wearing dentures (WID), and the data obtained were recorded as WID condition values. The comparison of mean PO values obtained from WOD and WID were analyzed with the Wilcoxon signed- rank test (α=.05). ResultsSignificant differences were found between WOD and WID values in terms of TRE (P=.01), ODI (P=.001), ALSpO2 (P=.006), TPE (P=.001), and HRVI (P=.001) parameters. The significance of the improvements in the WID condition increased with the severity of OSA. ConclusionsImprovements were observed in substantial cardiorespiratory parameters such as the ODI and HRVI of the participants wearing dentures nocturnally.

Frequent nightmares and its associations with psychological and sleep disturbances in hospitalized patients with cardiovascular diseases.

Frequent nightmares can pose a serious clinical problem, especially in association with sleep and psychological disturbances, in the general population. However, this association has not been investigated in inpatients with cardiovascular (CV) diseases. Furthermore, whether CV medications could induce iatrogenic nightmares remains unknown. In a cross-sectional designed study, we evaluated the prevalence and determinants of frequent nightmares and its association with sleep and psychological disturbances among hospitalized CV patients. A total of 1233 patients (mean age, 64 ± 15 years; 25.1% female) hospitalized for various CV diseases in a single university hospital were enrolled. We assessed nightmares and sleep characteristics using the Pittsburgh Sleep Quality Index (PSQI), sleep-disordered breathing (SDB) using nocturnal pulse oximetry, and psychological disturbances using Hospital Anxiety and Depression Scale (HADS). Overall, 14.8% and 3.6% of the patients had at least one nightmare per month and per week (frequent nightmares), respectively. In this cohort, 45.9% had insomnia (modified PSQI > 5), 28.0% had SDB (3% oxygen desaturation index > 15), 18.5% had depression (HADS-depression ≥ 8), and 16.9% had anxiety (HADS-anxiety ≥ 8). Frequent nightmares were not associated with CV medications and SDB but were associated with depression [odds ratio (OR) = 4.61, 95% confidence interval (CI) = 2.03-10.48], anxiety (OR = 5.32, 95% CI = 2.36-12.01), and insomnia (OR = 7.15, 95% CI = 2.41-21.22). Frequent nightmares were not uncommon in patients hospitalized for CV diseases. Although the cause-effect relationship is unclear, frequent nightmares were associated with psychological disturbances and insomnia, but not iatrogenic factors, among hospitalized CV patients. Cardiologists should be more conscientious to nightmare complaints with respect to screening for psychological disturbances and insomnia.

Assessment of Nocturnal Autonomic Cardiac Imbalance in Positional Obstructive Sleep Apnea. A Multiscale Nonlinear Approach.

Positional obstructive sleep apnea (POSA) is a major phenotype of sleep apnea. Supine-predominant positional patients are frequently characterized by milder symptoms and less comorbidity due to a lower age, body mass index, and overall apnea-hypopnea index. However, the bradycardia-tachycardia pattern during apneic events is known to be more severe in the supine position, which could affect the cardiac regulation of positional patients. This study aims at characterizing nocturnal heart rate modulation in the presence of POSA in order to assess potential differences between positional and non-positional patients. Patients showing clinical symptoms of suffering from a sleep-related breathing disorder performed unsupervised portable polysomnography (PSG) and simultaneous nocturnal pulse oximetry (NPO) at home. Positional patients were identified according to the Amsterdam POSA classification (APOC) criteria. Pulse rate variability (PRV) recordings from the NPO readings were used to assess overnight cardiac modulation. Conventional cardiac indexes in the time and frequency domains were computed. Additionally, multiscale entropy (MSE) was used to investigate the nonlinear dynamics of the PRV recordings in POSA and non-POSA patients. A total of 129 patients (median age 56.0, interquartile range (IQR) 44.8–63.0 years, median body mass index (BMI) 27.7, IQR 26.0–31.3 kg/m2) were classified as POSA (37 APOC I, 77 APOC II, and 15 APOC III), while 104 subjects (median age 57.5, IQR 49.0–67.0 years, median BMI 29.8, IQR 26.6–34.7 kg/m2) comprised the non-POSA group. Overnight PRV recordings from positional patients showed significantly higher disorderliness than non-positional subjects in the smallest biological scales of the MSE profile (τ = 1: 0.25, IQR 0.20–0.31 vs. 0.22, IQR 0.18–0.27, p < 0.01) (τ = 2: 0.41, IQR 0.34–0.48 vs. 0.37, IQR 0.29–0.42, p < 0.01). According to our findings, nocturnal heart rate regulation is severely affected in POSA patients, suggesting increased cardiac imbalance due to predominant positional apneas.

Sensitivity of a sequential model based on a questionnaire (STOP-Bang vs Dixon) and nocturnal pulse oximetry for screening obstructive sleep apnea in patients with morbid obesity candidates for bariatric surgery

IntroductionObstructive sleep apnea (OSA) has a high incidence in patients with morbid obesity (MO) who are candidates for bariatric surgery (BS). Adequate screening would decrease the number of respiratory polygraphies (RPs). ObjectiveTo analyze the value of a sequential model consisting of a questionnaire (modified Dixon (DXM VS STOP-Bang) and nocturnal pulse oximetry (POX) in patients who were candidates for BS. MethodsA prospective study was conducted from July 1, 2014 to July 1, 2015 on candidates for BS, excluding those who have already undergone RP. Variables: questionnaires (Epworth, STOP-Bang, and DXM), anthropometric measurements, RP, and blood and gas tests. The sample was divided into patients with no or mild OSA (no OSA) and those with moderate to severe OSA (AHI>15). ResultsA total of 70 patients were analyzed, 46 (65.7%) of them females. Moderate to severe OSA was diagnosed in 26 (37.1%) patients. STOP-Bang and DXM were compared using ROC curves, and greater area under the curve (AUC) was found for the latter (0.873(0.74−0.930) vs 0.781(0.673−0.888)). STOP-Bang had greater sensitivity, 100%, as compared to 73.1% for DXM. ODI3% showed greater diagnostic yield (AUC=0.982 (0.970-1). Use of the sequential model with STOP-Bang>3, DXM>5, and DXM>3 would have avoided 41 (58.5%), 50 (71.4%), and 41 (58.5%) RPs and 0, 7 (10%), and 0 false negatives respectively. ConclusionUse of a sequential model based on the STOP-Bang and nocturnal POX is a useful tool for screening OSA in patients with MO candidates for BS, decreasing the number of RPs.