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Purpose The study aims to prospectively validate the prognostic value of oximetry alone or combined in a two-step strategy with a questionnaire for the exclusion of obstructive sleep apnea (OSA) in primary care. Methods A total of 140 subjects with suspected OSA were included from 54 participating primary care practices. All subjects completed the Philips questionnaire and underwent one night of oximetry prior to referral to a sleep center. The prognostic value of two strategies was evaluated against the diagnosis of the sleep center as the gold standard: (1) assume OSA and subsequently refer to a sleep center if the oxygen desaturation index (ODI) is ≥ 5 and (2) assume OSA and refer to a sleep center if the Philips questionnaire score is ≥ 55% (regardless of the ODI) or if the Philips questionnaire score is

In this study, the hypercapnic ventilatory response (HCVR) was measured, defined as the ventilation response to carbon dioxide tension (PCO2). We investigated which method, rebreathing or steady-state, is most suitable for measurement of the HCVR in healthy subjects, primarily based on reproducibility. Secondary outcome parameters were subject experience and duration. 20 healthy adults performed a rebreathing and steady-state HCVR measurement on two separate days. Subject experience was assessed using numeric rating scales (NRS). The intraclass correlation coefficient (ICCs) of the sensitivity to carbon dioxide above the ventilatory recruitment threshold and the projected apnoea threshold were calculated to determine the reproducibility of both methods. The ICCs of sensitivity were 0.89 (rebreathing) and 0.56 (steady-state). The ICCs of the projected apnoea threshold were 0.84 (rebreathing) and 0.25 (steady-state). The steady-state measurement was preferred by 16 out of 20 subjects; the differences in NRS scores were small. The hypercapnic ventilatory response measured using the rebreathing setup provided reproducible results, while the steady-state method did not. This may be explained by high variability in end-tidal PCO2. Differences in subject experience between the methods are small., The hypercapnic ventilatory response measured by a rebreathing setup is reproducible, as opposed to a steady-state setup http://ow.ly/yGDg30hStIB

Obstructive Sleep Apnea (OSA) is recognized as an increasing health risk, leading to daytime sleepiness and various medical conditions, such as hypertension and heart failure. Polysomnography (PSG), the gold standard to diagnose OSA, is a resource-intensive and expensive investigation confined to the hospital.Portable home monitoring, i.e. pulse oximetry, may become an acceptable OSA screening method. The novel nasal pulse oximeter sensor (Xhale Alar) adds the possibility of combining pulse oximetry (SpO2) with airflow analysis by an integrated thermistor, which might increase the diagnostic accuracy.In the Alar pilot study, 39 adults were measured during an overnight PSG recording together with the Alar sensor. This study aims to investigate the additional value of an airflow signal compared to SpO2 analysis in OSA screening. Both time and spectral features were extracted from SpO2 and airflow signals recorded with the Alar sensor. Leave one out cross-validation was used to develop Random Forest models in screening for apnea-hypopnea index (AHI) thresholds 5 and 10. Using both AHI ≥ 5 and AHI ≥ 10 as the diagnostic cutoff, the airflow signal shows respectively an AUC of 89% and 80% compared to 78% and 77% with SpO2 analysis, showing a higher performance using an airflow signal in screening adults for OSA.

Introduction: Obstructive sleep apnea (OSA) is common, and diagnosis requires expensive and laborious testing to assess the apnea hypopnea index (AHI). We performed an analysis to explore the relationship between the oxygen desaturation index (ODI) as measured with pulse oximetry and the AHI in our large portable monitoring (PM) database to find an optimal cutoff value for the ODI in order to be able to exclude AHI ≥ 5 on PM. Methods: Three thousand four hundred thirteen PM recordings were randomly divided into a training set (N = 2281) and a test set (N = 1132). The optimal cutoff for the ODI to exclude an AHI ≥ 5 on PM was determined in the training set and subsequently validated in the test set. Results: Area under the curve of the ODI to exclude an AHI ≥ 5 on PM was 0.997 in the training set and 0.996 in the test set. In the training set, the optimal cutoff to predict an AHI < 5 was an ODI < 5. Using this cutoff in the test set provided a sensitivity of 97.7%, a specificity of 97.0%, a positive predictive value of 99.2%, and a negative predictive value of 91.4%. Conclusion: An ODI < 5 predicts an AHI < 5 with high sensitivity and specificity when measured simultaneously using the same oximeter during PM recording.

Summary Background The existing screening modalities for pulmonary embolism (PE), such as D-dimer and clinical prediction rules, have low positive predictive values. With its capability to indicate pulmonary vascular abnormalities, the ratio of the transfer factor of the lungs for nitric oxide and the transfer factor of the lungs for carbon monoxide (TL,NO/TL,CO) might be an additional discriminating parameter. Methods Carbon monoxide/Nitric oxide diffusion measurements were performed on unselected patients seen on the emergency department for which due to suspected PE a computed tomography pulmonary angiogram (CTPA) was ordered. Results A total of 28 patients were included, PE was found in 12 on CTPA. Median TL,NO/TL,CO ratio was 4·09 (interquartile range (IQR) 3·83–4·40) in the no PE group versus 4·00 (IQR 3·78–4·32) in the PE group (P = 0·959). Median alveolar volume was 77·1% of predicted in the no PE group versus 71·0% of predicted in the PE group (P = 0·353). Median TL,CO was 75·8% of predicted in the no PE group versus 68·8% of predicted in the PE group (P = 0·120). Median TL,NO was 69·3% of predicted in the no PE group versus 60·5% of predicted in the PE group (P = 0·078). Conclusion The presented data indicate that the TL,NO/TL,CO ratio cannot be used to exclude PE.

Contains fulltext : 165971.pdf (Publisher’s version ) (Open Access) A noncontact mapping system (EnSite) was used for electroanatomical mapping of the bladder simultaneously with pressure flow study in three women with lower urinary tract symptoms. We selected the periods of obvious detrusor activity. Data were processed to remove baseline drift, and an envelope of electrovesicography (EVG) data was created. The correlation coefficient for the correlation between between the EVG envelope and the detrusor pressure (Pdet) was calculated. Bladder geometry was successfully created in all 3 patients. Simultaneous recording of EVG and pressure flow data was successful in 1 patient. Scatter plots were made of the highest correlation coefficient, showing a positive correlation between the Pdet and the envelope, and negative correlation between abdominal pressure (Pabd) and the envelope. Minimal electrical activity could be observed. Significant weak to moderate correlation coefficients were found for the correlations between Pdet and EVG and between Pabd and EVG.

Volumetric capnography might be used to exclude pulmonary embolism (PE) without the need for computed tomography pulmonary angiography. In a pilot study, a new parameter (CapNoPE) combining the amount of carbon dioxide exhaled per breath (carbon dioxide production (VCO2)), the slope of phase 3 of the volumetric capnogram (slope 3) and respiratory rate (RR) showed promising diagnostic accuracy (where CapNoPE=(VCO2×slope 3)/RR). To retrospectively validate CapNoPE for the exclusion of PE, the volumetric capnograms of 205 subjects (68 with PE) were analysed, based on a large multicentre dataset of volumetric capnograms from subjects with suspected PE at the emergency department. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve and diagnostic accuracy of the in-pilot established threshold (1.90 Pa·min) were calculated. CapNoPE was 1.56±0.97 Pa·min in subjects with PE versus 2.51±1.67 Pa·min in those without PE (p, Retrospective validation in a large multicentre dataset shows that a novel volumetric capnography derived parameter (CapNoPE) is decreased in patients with PE but its diagnostic accuracy seems too low to use in clinical practice http://ow.ly/Ogpg30m0HuU

The analysis of the in expired air as a function of the exhaled volume (volumetric capnography) might result in a more specific exclusion tool for pulmonary embolism (PE) in addition to the Wells-score and D-dimer. A novel combination of volumetric capnography parameters () should be decreased in PE and could possibly be used to decrease the number of requested computed tomography pulmonary angiograms (CTPA). Volumetric capnography measurements were performed on consecutive patients seen in the emergency department for which, due to suspected PE (due to increased D-dimer level or Wells-score), a CTPA was ordered. A total of 30 subjects were included, of which in 13 PE was seen on CTPA. Median was 4.36 kPa (IQR 3.92–4.88) in the no PE group versus 4.07 kPa (IQR 3.37–4.39) in the PE group (p = 0.086). Median of the novel parameter was 1.85 min.kPa dl−1 (IQR 1.21–3.00) in the no PE group versus 1.18 min.kPa dl−1 (IQR 0.61–1.38) in the PE group (p = 0.006). Using a threshold for the new parameter of 1.90 min.kPa dl−1 or higher to exclude PE resulted in a negative predictive value of 100% (95% CI: 77%–100%) and would have potentially excluded PE in 47% (95% CI: 26%–69%) of the no PE group without the need for CTPA. This pilot study introduces a novel parameter which is significantly decreased in PE subjects. Future studies regarding validation and addressing aspects such as reproducibility and normalization after treatment are needed to confirm its usability in excluding PE in the emergency department.