The exact underlying pathomechanism of central sleep apnea with Cheyne-Stokes respiration (CSA-CSR) is still unclear. Recent studies have demonstrated an association between cerebral white matter changes and CSA. A dysfunction of central respiratory control centers in the brainstem was suggested by some authors. Novel MR-imaging analysis tools now allow far more subtle assessment of microstructural cerebral changes. The aim of this study was to investigate whether and what severity of subtle structural cerebral changes could lead to CSA-CSR, and whether there is a specific pattern of neurodegenerative changes that cause CSR. Therefore, we examined patients with Fabry disease (FD), an inherited, lysosomal storage disease. White matter lesions are early and frequent findings in FD. Thus, FD can serve as a “model disease” of cerebral microangiopathy to study in more detail the impact of cerebral lesions on central sleep apnea.
People sometimes experience a strong emotional response to artworks. Previous studies have demonstrated that the peak emotional experience of chills (goose bumps or shivers) when listening to music involves psychophysiological arousal and a rewarding effect. However, many aspects of peak emotion are still not understood. The current research takes a new perspective of peak emotional response of tears (weeping, lump in the throat). A psychophysiological experiment showed that self-reported chills increased electrodermal activity and subjective arousal whereas tears produced slow respiration during heartbeat acceleration, although both chills and tears induced pleasure and deep breathing. A song that induced chills was perceived as being both happy and sad whereas a song that induced tears was perceived as sad. A tear-eliciting song was perceived as calmer than a chill-eliciting song. These results show that tears involve pleasure from sadness and that they are psychophysiologically calming; thus, psychophysiological responses permit the distinction between chills and tears. Because tears may have a cathartic effect, the functional significance of chills and tears seems to be different. We believe that the distinction of two types of peak emotions is theoretically relevant and further study of tears would contribute to more understanding of human peak emotional response.
High-flow nasal cannula oxygen (HFNC) is a relatively new therapy used in adults with respiratory failure. Whether it is superior to conventional oxygen therapy (COT) or to noninvasive mechanical ventilation (NIV) remains unclear. The aim of the present study was to investigate whether HFNC was superior to either COT or NIV in adult acute respiratory failure patients.
Background and study aims: Drugs administered during gastrointestinal procedures cause increased collapsibility of the upper airway, which may lead to respiratory impairment. We evaluated the ability of continuous negative external pressure (cNEP) to lessen respiratory impairment during screening colonoscopy. Patients and methods: The initial 24 patients served as controls, while the next 30 received cNEP. cNEP was delivered by a soft silicone collar placed over the anterior neck. The primary endpoint was the frequency of respiratory impairment, defined as either: (i) a decline from baseline of > 4 % in oxygen saturation, or (ii) apnea lasting ≥ 20 seconds. Results: Mean respiratory impairment episodes were 3.50 in the no-cNEP group vs. 1.92 in the cNEP group, a reduction of 45 % (P = 0.022). Apneas ≥ 20 seconds occurred in 74 % of the no-cNEP group and 28 % of the cNEP group (P = 0.002). While 42 % of the no-cNEP group required increased supplemental oxygen, this was true for only 10 % of the cNEP group (P = 0.01). cNEP adverse events were minimal. Conclusions: During screening colonoscopy, sedation-related respiratory impairment is significantly reduced by cNEP.ClinicalTrials.gov NCT01895062.
Shewanella oneidensis couples oxidation of lactate to respiration of many substrates. Here we report that llpR (l-lactate-positive regulator, SO_3460) encodes a positive regulator of l-lactate utilization distinct from previously studied regulators. We also demonstrate d-lactate inhibition of l-lactate utilization in S. oneidensis, resulting in preferential utilization of the d isomer.
Abstract Objective: The aim of the study is to evaluate the application of Neurally Adjusted Ventilatory Assist (NAVA) in the respiratory weaning of patients affected by congenital diaphragmatic hernia (CDH). Methods: We analyzed the NAVA weaning in 12 neonates affected by CDH, relating the effectiveness of the electrical activation of the diaphragm (EAdi) signal to the type of CDH repair (with or without patch), the size of the patch, the stomach and His angle position, and the trend evaluation of some cardio-respiratory parameters with NAVA compared to pressure-support-ventilation (PSV). Results: 5 neonates submitted to primary repair showed a regular EAdi signal and were successfully weaned with NAVA. Of the 7 patients submitted to patch repair, 5 operated with patch limited to the diaphragmatic postero-lateral area had an active EAdi signal that permitted weaning with NAVA. Only in 2 neonates with hemidiaphragm agenesis was NAVA not feasible due to the impossibility to capture the EAdi signal. Compared to PSV, NAVA allows a significant improvement of oxygenation-linked indexes and paCO(2), while PIP is reduced. Conclusion: Neonatal CDH with a postero-lateral diaphragmatic defect allows the NAVA catheter to obtain a correct EAdi signal and develop a viable NAVA ventilation. The lower risk of lung injury in NAVA appears compatible with current ventilatory strategies considered useful in CDH.
The Effects of Different Oxygen Concentrations on Recruitment Maneuver During General Anesthesia for Laparoscopic Surgery
- Surgical laparoscopy, endoscopy & percutaneous techniques
- Published almost 5 years ago
Recruitment maneuvers (RMs), which aim to ventilate the collaborated alveolus by temporarily increasing the transpulmonary pressure, have positive effects in relation to respiration, mainly oxygenation. Although many studies have defined the pressure values used during RM and the application period, our knowledge of the effects of different oxygen concentrations is limited. In this study, we aimed to determine the effects of different oxygen concentrations during RM on the arterial oxygenation and respiration mechanics in laparoscopic cases.
A UWB Radar Signal Processing Platform for Real-Time Human Respiratory Feature Extraction Based on Four-Segment Linear Waveform Model
- IEEE transactions on biomedical circuits and systems
- Published about 4 years ago
This paper presents an ultra-wideband (UWB) impulse-radio radar signal processing platform used to analyze human respiratory features. Conventional radar systems used in human detection only analyze human respiration rates or the response of a target. However, additional respiratory signal information is available that has not been explored using radar detection. The authors previously proposed a modified raised cosine waveform (MRCW) respiration model and an iterative correlation search algorithm that could acquire additional respiratory features such as the inspiration and expiration speeds, respiration intensity, and respiration holding ratio. To realize real-time respiratory feature extraction by using the proposed UWB signal processing platform, this paper proposes a new four-segment linear waveform (FSLW) respiration model. This model offers a superior fit to the measured respiration signal compared with the MRCW model and decreases the computational complexity of feature extraction. In addition, an early-terminated iterative correlation search algorithm is presented, substantially decreasing the computational complexity and yielding negligible performance degradation. These extracted features can be considered the compressed signals used to decrease the amount of data storage required for use in long-term medical monitoring systems and can also be used in clinical diagnosis. The proposed respiratory feature extraction algorithm was designed and implemented using the proposed UWB radar signal processing platform including a radar front-end chip and an FPGA chip. The proposed radar system can detect human respiration rates at 0.1 to 1 Hz and facilitates the real-time analysis of the respiratory features of each respiration period.
The locus coeruleus (LC) has established functions in both attention and respiration. Good attentional performance requires optimal levels of tonic LC activity, and must be matched to task consistently. LC neurons are chemosensitive, causing respiratory phrenic nerve firing to increase frequency with higher CO2 levels, and as CO2 level varies with the phase of respiration, tonic LC activity should exhibit fluctuations at respiratory frequency. Top-down modulation of tonic LC activity from brain areas involved in attentional regulation, intended to optimize LC firing to suit task requirements, may have respiratory consequences as well, as increases in LC activity influence phrenic nerve firing. We hypothesize that, due to the physiological and functional overlaps of attentional and respiratory functions of the LC, this small neuromodulatory nucleus is ideally situated to act as a mechanism of synchronization between respiratory and attentional systems, giving rise to a low-amplitude oscillation that enables attentional flexibility, but may also contribute to unintended destabilization of attention. Meditative and pranayama practices result in attentional, emotional, and physiological enhancements that may be partially due to the LC’s pivotal role as the nexus in this coupled system. We present original findings of synchronization between respiration and LC activity (via fMRI and pupil dilation) and provide evidence of a relationship between respiratory phase modulation and attentional performance. We also present a mathematical dynamical systems model of respiratory-LC-attentional coupling, review candidate neurophysiological mechanisms of changes in coupling dynamics, and discuss implications for attentional theory, meditation, and pranayama, and possible therapeutic applications.
Panic disorder (PD) is associated with hyperventilation. The efficacy of a brief respiratory feedback program for PD has been established. The aim of the present study was to expand these results by testing a similar program with more clinically representative patients and settings. Sixty-nine adults with PD received 4 weeks of Capnometry Guided Respiratory Intervention (CGRI) using Freespira, which provides feedback of end-tidal CO2 (PETCO2) and respiration rate (RR), in four non-academic clinical settings. This intervention is delivered via home use following initial training by a clinician and provides remote monitoring of client adherence and progress by the clinician. Outcomes were assessed post-treatment and at 2- and 12-month follow-up. CGRI was associated with an intent-to-treat response rate of 83% and a remission rate of 54%, and large decreases in panic severity. Similar decreases were found in functional impairment and in global illness severity. Gains were largely sustained at follow-up. PETCO2 moved from the slightly hypocapnic range to the normocapnic range. Benchmarking analyses against a previously-published controlled trial showed very similar outcomes, despite substantial differences in sample composition and treatment settings. The present study confirms prior clinical results and lends further support to the viability of CGRI in the treatment of PD.