Effects of Bolus Holding on Respiratory–Swallow Coordination in Parkinson's Disease

Purpose: The aim of this study was to examine the effects of bolus holding on respiratory–swallow coordination (RSC) in people with Parkinson's disease (PD). Method: People with PD were prospectively recruited to undergo RSC assessment using simultaneous respiratory inductive plethysmography and flexible laryngoscopy. During RSC assessment, participants swallowed 5-ml thin liquid boluses during held and nonheld swallowing tasks. Measures of RSC were analyzed for each swallow, which included respiratory pause duration, lung volume at swallow initiation, respiratory phase patterning, and the presence of paradoxical respiratory movements. Multilevel statistical modeling was used to determine if differences in RSC were present between the held and nonheld tasks. Results: Thirty-three participants were enrolled. When compared to the nonheld swallows, the held swallows exhibited shorter respiratory pauses ( p = .001, R 2 = .019), lower lung volumes at swallow initiation ( p < .001, R 2 = .116), more frequent exhale–swallow–exhale patterns ( p < .001, OR = 4.30), and less frequent paradoxical respiratory movements ( p = .001, OR = 0.43). Conclusions: Findings from this study revealed that bolus holding significantly influences RSC in people with PD. This demonstrates that bolus holding may be an efficacious strategy to immediately improve RSC in PD. However, clinicians and researchers should consider avoiding bolus holding during swallowing evaluations if attempting to assess RSC behaviors that are most typical for the examinee.

Cardiopulmonary coupling analysis using smart wearables and mobile computing

Cardiopulmonary coupling (CPC) analysis links heart and respiration rates to assess sleep-related parameters. Typically, the CPC is measured using multi-lead electrocardiography (ECG) and ECG-derived respiration (EDR). Novel textile shirts with embedded ECG sensors offer convenient and continuously monitored sleep at home. We investigate the feasibility of a shirt with textile sensors (Pro- Kit, Hexoskin, Quebec, Canada) for CPC analysis by mobile computing. ECG data is continuously transmitted from the shirt to a smartphone via Bluetooth Low Energy (BLE). We customize a CPC algorithm and use twelve whole-night recordings from four volunteers to perform qualitative and quantitative analysis. We compare EDR with respiratory inductive plethysmography (RIP). In average, EDR and RIP differ 17.22%. After one night, the batteries are reduced to approx. 70% (shirt) and 90% (smartphone). The run time for CPC processing is approx. 3 min. Hence, smart wearables in combination with mobile computing show technical feasibility for CPC analysis. Eventually, this could yield a useful solution for sleep analysis of non-expert users in a private environment.

An Exploration of Lung Volume Effects on Swallowing in Chronic Obstructive Pulmonary Disease

Purpose Chronic obstructive pulmonary disease (COPD) limits respiration, which may negatively impact airway safety during swallowing. It is unknown how differences in lung volume in COPD may alter swallowing physiology. This exploratory study aimed to determine how changes in lung volume impact swallow duration and coordination in persons with stable state COPD compared with older healthy volunteers (OHVs). Method Volunteers ≥ 45 years with COPD (VwCOPDs; n = 9) and OHVs ( n = 10) were prospectively recruited. Group and within-participant differences were examined when swallowing at different respiratory volumes: resting expiratory level (REL), tidal volume (TV), and total lung capacity (TLC). Participants swallowed self-administered 20-ml water boluses by medicine cup. Noncued (NC) water swallows were followed by randomly ordered block swallowing trials at three lung volumes. Estimated lung volume (ELV) and respiratory–swallow patterning were quantified using spirometry and respiratory inductive plethysmography. Manometry measured pharyngeal swallow duration from onset of base of tongue pressure increase to offset of negative pressure in the pharyngoesophageal segment. Results During NC swallows, the VwCOPDs swallowed at lower lung volumes than OHVs ( p = .011) and VwCOPDs tended to inspire after swallows more often than OHVs. Pharyngeal swallow duration did not differ between groups; however, swallow duration significantly decreased as the ELV increased in VwCOPDs ( p = .003). During ELV manipulation, the COPD group inspired after swallowing more frequently at REL than at TLC ( p = .001) and at TV ( p = .002). In conclusion, increasing respiratory lung volume in COPD should improve safety by reducing the frequency of inspiration after a swallow.

TIME TO LUNG VOLUME STABILITY AFTER PRESSURE CHANGE DURING HIGH-FREQUENCY OSCILLATORY VENTILATION

ABSTRACTObjectivesClinicians have little guidance on the time needed before assessing the effect of a mean airway pressure (PAW) change during high-frequency oscillatory ventilation (HFOV). We aimed to determine 1) time to stable lung volume after a PAW change during HFOV and, 2) the relationship between time to volume stability and the volume state of the lung.MethodsContinuous lung volume measurements (respiratory inductive plethysmography) after 1-2 cmH2O PAW changes made every 10 minutes during an open lung strategy (n=13 infants) were analysed with a bi-exponential model. Time to stable lung volume (extrapolated to maximum 3600s) was calculated if the model R2 was >0.6.Results196 PAW changes were made, with no volume change in 33 (17%) occurrences. 125 volume signals met modelling criteria for inclusion; median (IQR) R2 0.96 (0.91, 0.98). The time to stable lung volume was 1131 (718, 1959)s (PAW increases) and 647 (439, 1309)s (PAW decreases), with only 17 (14%) occurring within 10 minutes and time to stability being longer when the lung was atelectatic.ConclusionsDuring HFOV, the time to stable lung volume after a PAW change is variable, often requires more than 10 minutes and is dependent on the preceding volume state.Impact StatementIn infants without preterm respiratory distress syndrome the time to achieve lung volume stability after a PAW change during HFOV is usually greater than 10 minutes.The volume state of the lung at the time of PAW change influences the time required to achieve a stable new lung volume; being shorter when the lung is well recruited and longer when the lung is already atelectatic.Clinicians should be aware that it may require least 10 minutes before assessing the clinical response to a change in PAW during HFOV

Respiratory–Swallow Coordination Training Improves Swallowing Safety and Efficiency in a Person With Anoxic Brain Injury

Purpose The aim of this study was to assess the effects of respiratory–swallow coordination training (RSCT) on respiratory–swallow coordination (RSC), swallowing safety (penetration/aspiration), and swallowing efficiency (pharyngeal residue) in a person with anoxic brain injury. Method A 68-year-old man with anoxic brain injury, tachypnea, and severe dysphagia was recruited to participate in a prospective AABAA single-subject experimental design. RSC, swallowing safety, and swallowing efficiency were measured at each assessment using respiratory inductive plethysmography and flexible endoscopic evaluations of swallowing. Data were analyzed descriptively using Cohen's d effect size. Outcome measures were compared pre-RSCT to post-RSCT, and pre-RSCT to a 1-month retention assessment. Results Improvements in RSC were observed immediately post-RSCT ( d = 0.60). These improvements were maintained upon retention assessment 1 month later ( d = 0.60). Additionally, improvements in swallowing safety ( d = 1.73), efficiency ( d = 1.73), and overall dysphagia severity ( d = 1.73) were observed immediately post-RSCT and were maintained upon retention assessment 1 month later ( d = 1.73). Conclusions Clinically meaningful improvements in RSC were observed following four sessions of RSCT, which were subsequently associated with large improvements in swallowing safety and efficiency. RSCT may be an efficacious, clinically feasible skill-based exercise for people with anoxic brain injury, suboptimal RSC, and dysphagia. Future work is needed to expand these findings in a larger cohort of people with dysphagia.

Respiratory Rates Derived From Arterial Blood Pressure Waveforms in Telemetered Dogs

The objective of this study was to extract low frequency respiratory “artifacts” from a standard arterial blood pressure (ABP) waveform to simultaneously derive reliable breathing rates (BR). Arterial blood pressure derived BR values were characterized against respiratory rates simultaneously obtained from the Respiratory Inductive Plethysmography (RIP) system (EMKA). Reference compounds were introduced to evaluate responsiveness of the derived measures to respiratory depressants and stimulants. Male beagle dogs (n = 3) were instrumented with minimally invasive telemetry devices for measurements of ABP and heart rate. The RIP system was utilized simultaneously to collect respiratory rate, tidal volume, and minute volume of each animal following pharmacological challenges. Early results revealed the derived BR’s from ABP waveforms did not correlate well with those measured from the RIP system. Post study X-ray visualization revealed suboptimal catheter positioning, causing poor concordance of BR tallied from the ABP waveforms. Follow-up evaluations were conducted using additional animals instrumented with the ABP catheter tip placement advanced proximal to the thoracic diaphragm. Preliminary data from this subset of animals significantly improved the correlation of BR derived from ABP and respiratory rates recorded by the RIP. This proof of concept investigation was intended to evaluate an algorithm designed to extract additional data from routine cardiac waveforms. We clearly demonstrated that with optimal blood pressure catheter placement and acquisition algorithm, a reliable breathing rate can also be extracted from safety studies without the need for additional studies/animals to capture those respiratory end points.

Respiratory–Swallow Coordination Training and Voluntary Cough Skill Training: A Single-Subject Treatment Study in a Person With Parkinson's Disease

Purpose Airway protective disorders are common in Parkinson's disease (PD), yet effective methods to rehabilitate these life-threatening impairments are limited. This study examined the effects of two skill-based treatments aimed at improving swallowing and cough in a severely dysphagic person with PD: respiratory–swallow coordination training (RSCT) and voluntary cough skill training (VCST). It was hypothesized that (a) RSCT would improve respiratory–swallow coordination and swallowing safety and efficiency and (b) VCST would improve reflex and voluntary cough effectiveness. Method An 81-year-old man with midstage PD and severe dysphagia was recruited for study participation. The study utilized a multiple-baseline ABACA experimental design with a 2-month delayed retention assessment. Measures of respiratory–swallow coordination, swallowing safety and efficiency, and cough effectiveness were collected at each assessment using respiratory inductive plethysmography, flexible endoscopic evaluations of swallowing, and spirometry. Data were analyzed descriptively using baseline corrected tau and standard mean difference effect sizes ( d ). Results Large effect sizes were observed immediately following RSCT for respiratory–swallow coordination ( d = 9.17), penetration–aspiration ( d = 12.88), vallecular residue ( d = 1.75), piriform residue ( d = 4.15), and overall dysphagia severity ( d = 1.83). Large effect sizes were also observed immediately following VCST for single voluntary cough ( d = 4.30), sequential voluntary cough ( d = 3.28), and reflex cough ( d = 5.58). Improvements were maintained 2 months later for all outcome measures except single voluntary cough. Discussion This is the first study to examine the effects of RSCT and VCST in a person with PD. Robust improvements in respiratory–swallow coordination and swallowing safety and efficiency were achieved following four sessions of RSCT, and significant improvements in reflex and voluntary cough strength were seen following four sessions of VCST. Future work is needed to study these treatments in larger cohorts of people with PD.

Altered Causal Coupling Pathways within the Central-Autonomic-Network in Patients Suffering from Schizophrenia

The multivariate analysis of coupling pathways within physiological (sub)systems focusing on identifying healthy and diseased conditions. In this study, we investigated a part of the central-autonomic-network (CAN) in 17 patients suffering from schizophrenia (SZO) compared to 17 age–gender matched healthy controls (CON) applying linear and nonlinear causal coupling approaches (normalized short time partial directed coherence, multivariate transfer entropy). Therefore, from all subjects continuous heart rate (successive beat-to-beat intervals, BBI), synchronized maximum successive systolic blood pressure amplitudes (SYS), synchronized calibrated respiratory inductive plethysmography signal (respiratory frequency, RESP), and the power PEEG of frontal EEG activity were investigated for 15 min under resting conditions. The CAN revealed a bidirectional coupling structure, with central driving towards blood pressure (SYS), and respiratory driving towards PEEG. The central-cardiac, central-vascular, and central-respiratory couplings are more dominated by linear regulatory mechanisms than nonlinear ones. The CAN showed significantly weaker nonlinear central-cardiovascular and central-cardiorespiratory coupling pathways, and significantly stronger linear central influence on the vascular system, and on the other hand significantly stronger linear respiratory and cardiac influences on central activity in SZO compared to CON, and thus, providing better understanding of the interrelationship of central and autonomic regulatory mechanisms in schizophrenia might be useful as a biomarker of this disease.