Pulmonary Rehabilitation in Patients with Neuromuscular Disease

In neuromuscular disease (NMD) patients with progressive muscle weakness, respiratory muscles are also affected and hypercapnia can increase gradually as the disease progresses. The fundamental respiratory problems NMD patients experience are decreased alveolar ventilation and coughing ability. For these reasons, it is necessary to precisely evaluate pulmonary function to provide the proper inspiratory and expiratory muscle aids in order to maintain adequate respiratory function. As inspiratory muscle weakening progresses, NMD patients experience hypoventilation. At this point, respiratory support by mechanical ventilator should be initiated to relieve respiratory distress symptoms. Patients with adequate bulbar muscle strength and cognitive function who use a non-invasive ventilation aid, via a mouthpiece or a nasal mask, may have their hypercapnia and associated symptoms resolved. For a proper cough assist, it is necessary to provide additional insufflation to patients with inspiratory muscle weakness before using abdominal thrust. Another effective method for managing airway secretions is a device that performs mechanical insufflation-exsufflation. In conclusion, application of non-invasive respiratory aids, taking into consideration characterization of respiratory pathophysiology, have made it possible to maintain a better quality of life in addition to prolonging the life span of patients with NMD

Different Methods to Improve the Monitoring of Noninvasive Respiratory Support of Patients with Severe Pneumonia / ARDS Due to COVID-19: An Update.

The last guidelines for the hospital care of patients affected by coronavirus disease-2019 (COVID-19)-related acute respiratory failure have moved towards a widely accepted use of noninvasive respiratory support (NIRS) as opposed to early intubation at the pandemic onset. The establishment of severe COVID-19 pneumonia goes through different pathophysiological phases that partially resemble typical acute respiratory distress syndrome (ARDS) and have been categorized into different clinicalradiological phenotypes. These can variably benefit on the application of external positive end-expiratory pressure (PEEP) during noninvasive mechanical ventilation, mainly due to variable levels of lung recruit ability and lung compliance during different phases of the disease. A growing body of evidence suggests that intense respiratory effort producing excessive negative pleural pressure swings (Ppl) plays a critical role in the onset and progression of lung and diaphragm damage in patients treated with noninvasive respiratory support. Routine respiratory monitoring is mandatory to avoid the nasty continuation of NIRS in patients who are at higher risk for respiratory deterioration and could benefit from early initiation of invasive mechanical ventilation instead. Here we propose different monitoring methods both in the clinical and experimental settings adapted for this purpose, despite further research is required to allow their extensive application in clinical practice. We reviewed the needs and available tools for a clinical-physiological monitoring that aims at optimizing the ventilatory management of patients affected by acute respiratory distress syndrome due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection

Change in pulmonary mechanics and the effect on breathing pattern of high flow oxygen therapy in stable hypercapnic Chronic Obstructive Pulmonary Disease

Chronic hypercapnic respiratory failure (CHF) represents a major issue in stable chronic obstructive pulmonary disease (COPD). Non-invasive Ventilation (NIV) improves pulmonary gas exchange function with decrease in PaCO2 and rise in pH. Long-term NIV reduces mortality in these patients and time to first exacerbations, but adherence to ventilatory therapy is poor. High Flow Oxygen Therapy (HFOT) could counterbalance the effect of intrinsic Positive End Expiratory Pressure (PEEPi) and optimize Ventilation/Perfusion ratio through the modification of breathing pattern; then, HFOT could be an appealing alternative to home NIV. Therefore, in order to assess HFOT effects on respiratory work of breathing, compared to NIV as gold standard, we studied the consequences of these two form of non-invasive respiratory support on: inspiratory effort, as assessed by measuring transdiaphragmatic pressure; breathing pattern; gas exchange. Fourteen patients with hypercapnic stable COPD underwent five 30-min trials, in a random order: HFOT at two flow rates (20 L/min and 30 L/min), both with open and closed mouth, and NIV. After each trial, standard oxygen therapy was reinstituted for ten min. Compared with baseline, HFOT and NIV significantly improved breathing pattern, although to different extents, and reduced inspiratory effort; however, arterial carbon dioxide oxygen tension decreased but not significantly. These results indicate a possible role for HFOT in the long-term management of patients with hypercapnic stable COPD, because of no rise in PaCO2, and improved respiratory mechanic

An investigation into the effects of commencing haemodialysis in the critically ill

<b>Introduction:</b> We have aimed to describe haemodynamic changes when haemodialysis is instituted in the critically ill. 3 hypotheses are tested: 1)The initial session is associated with cardiovascular instability, 2)The initial session is associated with more cardiovascular instability compared to subsequent sessions, and 3)Looking at unstable sessions alone, there will be a greater proportion of potentially harmful changes in the initial sessions compared to subsequent ones. <b>Methods:</b> Data was collected for 209 patients, identifying 1605 dialysis sessions. Analysis was performed on hourly records, classifying sessions as stable/unstable by a cutoff of >+/-20% change in baseline physiology (HR/MAP). Data from 3 hours prior, and 4 hours after dialysis was included, and average and minimum values derived. 3 time comparisons were made (pre-HD:during, during HD:post, pre-HD:post). Initial sessions were analysed separately from subsequent sessions to derive 2 groups. If a session was identified as being unstable, then the nature of instability was examined by recording whether changes crossed defined physiological ranges. The changes seen in unstable sessions could be described as to their effects: being harmful/potentially harmful, or beneficial/potentially beneficial. <b>Results:</b> Discarding incomplete data, 181 initial and 1382 subsequent sessions were analysed. A session was deemed to be stable if there was no significant change (>+/-20%) in the time-averaged or minimum MAP/HR across time comparisons. By this definition 85/181 initial sessions were unstable (47%, 95% CI SEM 39.8-54.2). Therefore Hypothesis 1 is accepted. This compares to 44% of subsequent sessions (95% CI 41.1-46.3). Comparing these proportions and their respective CI gives a 95% CI for the standard error of the difference of -4% to 10%. Therefore Hypothesis 2 is rejected. In initial sessions there were 92/1020 harmful changes. This gives a proportion of 9.0% (95% CI SEM 7.4-10.9). In the subsequent sessions there were 712/7248 harmful changes. This gives a proportion of 9.8% (95% CI SEM 9.1-10.5). Comparing the two unpaired proportions gives a difference of -0.08% with a 95% CI of the SE of the difference of -2.5 to +1.2. Hypothesis 3 is rejected. Fisher’s exact test gives a result of p=0.68, reinforcing the lack of significant variance. <b>Conclusions:</b> Our results reject the claims that using haemodialysis is an inherently unstable choice of therapy. Although proportionally more of the initial sessions are classed as unstable, the majority of MAP and HR changes are beneficial in nature

Effects of reduced rebreathing time, in spontaneously breathing patients, on respiratory effort and accuracy in cardiac output measurement when using a partial carbon dioxide rebreathing technique: a prospective observational study

INTRODUCTION: New technology using partial carbon dioxide rebreathing has been developed to measure cardiac output. Because rebreathing increases respiratory effort, we investigated whether a newly developed system with 35 s rebreathing causes a lesser increase in respiratory effort under partial ventilatory support than does the conventional system with 50 s rebreathing. We also investigated whether the shorter rebreathing period affects the accuracy of cardiac output measurement. METHOD: Once a total of 13 consecutive post-cardiac-surgery patients had recovered spontaneous breathing under pressure support ventilation, we applied a partial carbon dioxide rebreathing technique with rebreathing of 35 s and 50 s in a random order. We measured minute ventilation, and arterial and mixed venous carbon dioxide tension at the end of the normal breathing period and at the end of the rebreathing periods. We then measured cardiac output using the partial carbon dioxide rebreathing technique with the two rebreathing periods and using thermodilution. RESULTS: With both rebreathing systems, minute ventilation increased during rebreathing, as did arterial and mixed venous carbon dioxide tensions. The increases in minute ventilation and arterial carbon dioxide tension were less with 35 s rebreathing than with 50 s rebreathing. The cardiac output measures with both systems correlated acceptably with values obtained with thermodilution. CONCLUSION: When patients breathe spontaneously the partial carbon dioxide rebreathing technique increases minute ventilation and arterial carbon dioxide tension, but the effect is less with a shorter rebreathing period. The 35 s rebreathing period yielded cardiac output measurements similar in accuracy to those with 50 s rebreathing

The Perception of Skills for Maximizing Patient Comfort During Non-Invasive Ventilation Among Respiratory Therapists at KFSH&RC

Background: Noninvasive ventilation (NIV) is a modality that supports patient breathing through different types of face ‏interfaces, such as a full-face mask and nasal mask. Noninvasive Ventilation modalities have proven to improve morbidity and mortality rates for patients suffering from respiratory failure in the hospital setting and Outpatient. It also helped prevent escalating the treatment to more advanced methods such as invasive ventilation. However, several elements are required for optimizing the therapy, including Health care providers\u27 training in operating the different brands of NIV, equipment availability, cost, and appropriate adjustment to the settings according to patient response. Purpose: This study aims to assess the level of perception of maximizing patient comfort during non-invasive ventilation devices among respiratory therapists at KFSH&RC by utilizing specific features of NIV. For instance, ramp, Flex, humidification, and auto-adjusting pressure. In addition, how RTs perceive mask selection and other contributing factors that contribute to maximizing patients\u27 comfort. Methods: The study used an online, cross-sectional survey with 20 questions were sent to Respiratory therapists at KFSH&RC. In this survey, data collected from targeted population regarding their perceptions of skills for maximizing patient comfort during non-invasive ventilation will be analyzed using the Statistical Package for the Social Sciences (SPSS). Result: The findings indicated that respiratory therapists at KFSH&RC generally hold a positive view about utilizing various aspects of NIV, such as auto-adjusting pressure, noise reduction, humidification, and specific NIV settings, to maximize patient comfort. They also recognized the importance of effective communication, patient encouragement, and addressing patient comfort before and after initiating NIV therapy. The study found that demographic factors like gender, country of graduation, years of experience, and age did not significantly impact the therapists\u27 attitudes, except for therapists working in respiratory care community services (RCCS), who placed greater emphasis on maximizing patient comfort during NIV (P=.019). Conclusion: This research conducted at King Faisal Specialist Hospital & Research Centre (KFSH&RC) concluded that respiratory therapists demonstrated positive perception about utilizing different elements of NIV to maximize patient comfort during therapy. Majority of therapists believed that features such as auto-adjusting pressure, noise reduction, humidification, and the utilization of certain NIV settings such as the FLEX and RAMP have significance for enhancing patient comfort

Technology Development Standardization and Evaluation in Pulmonary Medicine

book chapterBiomedical Informatic

Effects of the components of positive airway pressure on work of breathing during bronchospasm

INTRODUCTION: Partial assist ventilation reduces work of breathing in patients with bronchospasm; however, it is not clear which components of the ventilatory cycle contribute to this process. Theoretically, expiratory positive airway pressure (EPAP), by reducing expiratory breaking, may be as important as inspiratory positive airway pressure (IPAP) in reducing work of breathing during acute bronchospasm. METHOD: We compared the effects of 10 cmH(2)O of IPAP, EPAP, and continuous positive airwaypressure (CPAP) on inspiratory work of breathing and end-expiratory lung volume (EELV) in a canine model of methacholine-induced bronchospasm. RESULTS: Methacholine infusion increased airway resistance and work of breathing. During bronchospasm IPAP and CPAP reduced work of breathing primarily through reductions in transdiaphragmatic pressure per tidal volume (from 69.4 ± 10.8 cmH(2)O/l to 45.6 ± 5.9 cmH(2)O/l and to 36.9 ± 4.6 cmH(2)O/l, respectively; P < 0.05) and in diaphragmatic pressure–time product (from 306 ± 31 to 268 ± 25 and to 224 ± 23, respectively; P < 0.05). Pleural pressure indices of work of breathing were not reduced by IPAP and CPAP. EPAP significantly increased all pleural and transdiaphragmatic work of breathing indices. CPAP and EPAP similarly increased EELV above control by 93 ± 16 ml and 69 ± 12 ml, respectively. The increase in EELV by IPAP of 48 ± 8 ml (P < 0.01) was significantly less than that by CPAP and EPAP. CONCLUSION: The reduction in work of breathing during bronchospasm is primarily induced by the IPAP component, and that for the same reduction in work of breathing by CPAP, EELV increases more