Inspiratory Flow Rate Research Articles

REVIEW OF MODERN DEVICES FOR INHALATION THERAPY

Inhalation therapy is the introduction of a medicinal substance directly into the respiratory tract using special inhalers. To date, more than 200 devices for inhalation therapy have been developed. The purpose of the work is to review modern devices for inhalation therapy, to clarify their advantages and disadvantages. Interest in inhalation therapy can be explained by several reasons. Let's list them. First, you can inject the drug directly into the respiratory system. Secondly, the therapeutic effect comes quickly. Thirdly, the drug is almost not absorbed into the blood, so there are no systemic side effects. In addition, the patient can do inhalation independently at home. At the same time, inhalation therapy has several disadvantages. Sometimes it is difficult for the patient to understand how to use the inhaler. The doctor should show, explain and control inhalation. The particle size of the aerosol is very important, as is the patient's inspiratory flow rate.

Impact of Breathing exercise and Inhalation Technique on patient’s Quality of Life among Asthma and COPD patients

Around 4 million deaths each year are caused by respiratory disorders worldwide. These diseases are a persistent threat to India as well; the number of people in India who suffer from COPD and asthma has been estimated to be 14.84 million and 17.23 million, respectively.In the present prospective and observational study, a total of 120 patients were enrolled, among 38 patients were diagnosed with Asthma and 82 were COPD patients. All the patients were trained with breathing exercises and inhalation techniques. The patients who have been prescribed with DPI and MDI inhalation devices were checked for their correct usage. The checklist score (DPI and MDI) for Asthma patients, before trainingwas 2.9 and after training was 8.1(<0.001***) and checklist score for COPD patients, before training was 2.8 and after training was 8.5(<0.001***).The results indicate that there is a significant increase (<0.001***) in correct usage after training session, which influences the inspiratory flow rate on Respirometer. Asthma Patient’s QoLwas measured by using ACT score, before training was 9.3 and after training was 19.7(<0.001***) and AQLQ score before training was 35.6 and after training was 74.1 (<0.001***). For COPD Patient’s QoLwas measured by using CAT score, before training was 33.2 and after training was 12.1(<0.001***) and MMRC score before training was 3.6 and after training was 1.4(<0.001***). In the present study breathing exercises increases inhalation capacity and hands on training for inhalation techniques improves the efficacy of drugs, together influences the patient’s Quality of Life (QoL) which reduces the number of days of hospitalization and socio-economic burden.

Cough Correlates of Functional Swallow Outcomes in Atypical Parkinsonism.

Swallow and cough impairments lead to aspiration and reduced clearance of aspirate material. Both behaviors are impaired in Parkinson's disease, but it is unknown whether a similar relationship of dysfunction exists in forms of atypical Parkinsonism (APD). Elucidating this association in APD may lead to early, comprehensive airway protection treatment. We tested the hypotheses that swallow deficits in APD are associated with impaired cough and that airway protective dysfunction is associated with longer disease duration. Swallowing difficulty was described by 11 participants with APD. Penetration-Aspiration Scale (PAS) and DIGEST scores for thin liquid trials were extracted from medical records of videofluoroscopic swallow study reports. Voluntary and capsaicin induced-reflex cough measures of flow, volume, and timing were analyzed. While most participants did not have post-swallow residue, ~80% received abnormal PAS scores and reported swallowing difficulty. Those with abnormal PAS scores had lower voluntary cough expired volume (P = 0.037; mean rank difference = 5.0); lower reflex inspiratory flow rate (P = 0.034; mean rank difference = 5.5); and longer reflex expiratory flow rise time (P = 0.034; mean rank difference = 5.5). Higher PAS scores and reduced reflex cough volume acceleration were significantly correlated (r = -0.63; P = 0.04) and longer disease duration predicted larger voluntary cough expired volume (R2 = 0.72) and longer flow rise times (R2 = 0.47). As swallow safety worsens, so might the ability to clear the airways with effective cough in in APD; particularly with longer disease duration. Assessing cough in conjunction with swallowing is important for informing airway protection treatment plans in APD.

Successful Use of Easyhaler® Dry Powder Inhaler in Patients with Chronic Obstructive Pulmonary Disease; Analysis of Peak Inspiratory Flow from Three Clinical Trials.

There is increasing pressure to use environmentally friendly dry powder inhalers (DPI) instead of pressurized metered-dose inhalers (pMDI). However, correct inhalation technique is needed for effective inhaler therapy, and there is persistent concern whether patients with chronic obstructive pulmonary disease (COPD) can generate sufficient inspiratory effort to use DPIs successfully. The aims of this study were to find clinical predictors for peak inspiratory flow rate (PIF) and to assess whether patients with COPD had difficulties in generating sufficient PIF with a high resistance DPI. Pooled data of 246 patients with COPD from previous clinical trials was analyzed to find possible predictors of PIF via the DPI Easyhaler (PIFEH) and to assess the proportion of patients able to achieve an inhalation flow rate of 30 l/min, which is needed to use the Easyhaler successfully. The mean PIF was 56.9l/min and 99% (243/246) of the study patients achieved a PIF ≥ 30l/min. A low PIF was associated with female gender and lower forced expiratory volume in 1s (FEV1), but the association was weak and a statistical model including both only accounted for 18% of the variation seen in PIFEH. Based on our results, impaired expiratory lung function or patient characteristics do not predict patients' ability to use DPIs in COPD; 99% of the patients generated sufficient PIFEH for successful dose delivery. Considering the targets for sustainability in health care, this should be addressed as DPIs are a potential option for most patients when choosing the right inhaler for the patient. Two of three included trials were registered under numbers NCT04147572 and NCT01424137. Third trial preceded registration platforms and therefore, was not registered.

Effect of Sildenafil in Neonates with Persistent Pulmonary Hypertension: An Interventional Study

Introduction: Persistent Pulmonary Hypertension of the Newborn (PPHN) reflects a disruption of the normal perinatal circulatory transition and is characterised by high pulmonary artery pressure. Inhaled Nitric Oxide (iNO) is considered the mainstay of treatment for PPHN. However, many developing and resource limited countries do not have access to such expensive therapy. Therefore, sildenafil, due to its easy availability and low cost, becomes the most commonly used drug in the management of PPHN in such settings. Aim: To study the treatment response and outcomes of neonates who received sildenafil for the management of PPHN. Materials and Methods: The present hospital-based prospective interventional study was conducted in the Neonatal Intensive Care Unit (NICU), BJ Medical College, Civil Hospital, Ahmedabad, Gujarat, between May 1, 2020, and April 30, 2021. Study was conducted on neonates with meconium aspiration syndrome and/or severe birth asphyxia admitted to the NICU. A total of 48 neonates with Two Dimensional (2D) echocardiography-proven PPHN were enrolled. Baseline clinical parameters including heart rate, respiratory rate, preductal and postductal Saturation of Peripheral Oxygen (SpO2), Oxygenation Index (OI), Saturation Oxygen Distending Pressure Index (SOPI), and Non Invasive Blood Pressure (NIBP) were monitored every six hours. Neonates who were on invasive/ non invasive ventilation had their Fraction of Inspired Oxygen (FiO2), Positive End Expiratory Pressure (PEEP), Peak Inspiratory Pressure (PIP), respiratory rate and flow rate monitored every six hours. Data were statistically analysed using Analysis of Variance (ANOVA) test. Results: During the study period, a total of 1080 neonates were admitted with meconium aspiration syndrome and/or severe birth asphyxia, out of which 48 neonates showed findings suggestive of PPHN on 2D echocardiography. A statistically significant improvement in oxygenation after sildenafil treatment was indicated by a significant reduction in OI from 35.3±8.6 to 13.2±2.1 (p-value<0.001), a reduction in SOPI from 3.6±0.3 to 1.5±0.2 (p-value<0.001), a reduction in FiO2 (%) from 94.6±8.19 to 24.2±4.5 (p-value<0.001), an increase in Partial pressure of oxygen (PaO2) (mmHg) from 52±5.6 to 72±3.4 (p-value<0.001), and an increase in SpO2 (%) from 83.5±8.6 to 93.5±5.1 (p-value<0.001). Conclusion: The findings of the present study suggest that oral sildenafil can be successfully used to improve oxygenation in patients with PPHN, especially in a resource limited setting where facilities like Extracorporeal Membrane Oxygenation (ECMO) and iNO are not available, as demonstrated in the present study.

Comparative Analysis of Peak Inspiratory Flow Rate at Discharge and Three-month Follow-up in Severe Acute Exacerbation of COPD Patients using Metered Dose Inhalers versus Dry Powder Inhalers: A Prospective Observational Study

Introduction: Patients discharged following hospitalisation for Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) are prescribed Metered Dose Inhalers (MDI), Dry Powder Inhalers (DPI), or nebulisers. Drug dispersion from the inhaler and deposition in the lung depends on Peak Inspiratory Flow Rate (PIFR) among other factors. A low PIFR results in suboptimal drug delivery and is a risk factor for readmission. Aim: To estimate PIFR at discharge following AECOPD, assess the type of inhalers prescribed at discharge, and estimate the mean change in PIFR at three months follow-up in patients using MDI and DPI. Materials and Methods: A prospective observational study was conducted at a tertiary care hospital, Goa Medical College, Goa, India on 138 patients over 15 months from November 2018 to February 2020. A sample size of 138 was calculated, and the study duration was 15 months. Patients admitted with AECOPD were enrolled in the study after obtaining informed consent. At discharge, baseline characteristics and co-morbidities were recorded, and PIFR was measured using an in-check dial peak inspiratory flow meter without resistance. Inhalers prescribed by the treating physician were verified and checked for errors. PIFR was measured at three months of follow-up. Optimal PIFR was defined as PIFR of ≥60 L/min. Statistical analysis was performed using the Statistical Package for Social Science Programs (SPSS) version 24.0 (IBM Corp, SPSS Inc, Chicago, IL). A paired t-test assessed the change in PIFR at discharge and three months follow-up, and Pearson’s correlation test was used to assess the correlation between continuous variables. Results: Total 138 were enrolled with a mean age of 69.8±7.5 years, 87 (63%) were males. The mean PIFR at discharge was 58.9±24.7 L/min. 85 (61.6%) had suboptimal PIFR and were older {71.9±7.8 versus 66.3±5.6, p-value=0.01}. A total of 59 (69.4%) with suboptimal PIFR received MDI. At three months, the suboptimal PIFR group receiving MDI showed a mean change in PIFR of 18.6±7.7, p-value<0.001 while with DPI mean change was -3.8±6.3, p-value=0.005. Conclusion: 61.6% had suboptimal PIFR at discharge following hospitalisation with AECOPD. Patients with suboptimal PIFR receiving MDI showed improvement in PIFR at three months, while those with suboptimal PIFR using DPI showed significant deterioration. Identifying patients with suboptimal PIFR will aid appropriate prescription of inhaler devices.

Hypopharyngeal geometry impact on air-induced loads on the supraglottis

Exercise-induced laryngeal obstruction (EILO) describes paradoxical laryngeal closure during inspiration at high-intensity exercise. It is hypothesised that during intense activity, the air-induced loads on supraglottic walls overcome their internal stiffness, leading to the obstruction. Recent investigations have revealed that the air-induced loads on the supraglottic walls vary nonlinearly with increasing flow rate. It is, however, unclear whether certain geometric configurations of the hypopharynx and larynx may contribute to the predisposition to EILO. This study investigates the influence of hypopharyngeal and laryngeal geometry on upper respiratory tract airflow and air-induced forces. A computational fluid dynamics model is developed to study airflow through larynx. Four real, adult upper respiratory tracts with variable configurations are considered. Two steady, uniform inspiratory flow rates of 60 L/min and 180 L/min are considered. The analysis shows that geometries with a space lateral to the epiglottis (EpiS) and piriform fossae (PF) directs the hypopharyngeal and supraglottic pressure field to remain positive and increase with the flow rate. In geometries with EpiS and PF, pressure differential occurs around the aryepiglottic fold producing a net inward force over the region. The three-fold increase in flow rate induces near ten-fold increases in force over the region which may facilitate the closure. It is concluded that hypopharyngeal anatomy, particularly the piriform fossae, play a significant role in the obstruction of the supraglottic airway and should be considered in research and clinical assessment of EILO.

Chinese expert consensus on standardized inhaler device application in stable chronic airway diseases (2023)

Chinese expert consensus on standardized inhaler device application in stable chronic airway diseases (2023)

Understanding the effects of inhaler resistance on particle deposition behaviour – A computational modelling study

Background and objectiveUnderstanding the impact of inhaler resistance on particle transport and deposition in the human upper airway is essential for optimizing inhaler designs, thereby contributing to the enhancement of the therapeutic efficacy of inhaled drug delivery. This study demonstrates the potential effects of inhaler resistance on particle deposition characteristics in an anatomically realistic human oropharynx and the United States Pharmacopeia (USP) throat using computational fluid dynamics (CFD). MethodMagnetic resonance (MR) imaging was performed on a healthy volunteer biting on a small mockup inhaler mouthpiece. Three-dimensional geometry of the oropharynx and mouthpiece were reconstructed from the MR images. CFD simulations coupled with discrete phase modelling were conducted. Inhaled polydisperse particles under two different transient flow profiles with peak inspiratory flow rates (PIFR) of 30 L/min and 60 L/min were investigated. The effect of inhaler mouthpiece resistance was modelled as a porous medium by varying the initial resistance (Ri) and viscous resistance (Rv). Three resistance values, 0.02 kPa0.5minL−1, 0.035 kPa0.5minL−1 and 0.05 kPa0.5 minL−1, were simulated. The inhaler outlet velocity was set to be consistent across all models for both flow rate conditions to enable a meaningful comparison of models with different inhaler resistances. ResultThe results from this study demonstrate that investigating the effect of inhaler resistance by solely relying on the USP throat model may yield misleading results. For the geometrically realistic oropharyngeal model, both the pressure and kinetic energy profiles at the mid-sagittal plane of the airway change dramatically when connected to a higher-resistance inhaler. In addition, the geometrically realistic oropharyngeal model appears to have a resistance threshold. When this threshold is surpassed, significant changes in flow dynamics become evident, which is not observed in the USP throat model. Furthermore, this study also reveals that the impact of inhaler resistance in a geometrically realistic throat model extends beyond the oral cavity and affects particle deposition downstream of the oral cavity, including the oropharynx region. ConclusionResults from this study suggest that key mechanisms underpinning the working principles of inhaler resistance are intricately connected to their complex interaction with the pharynx geometry, which affects the local pressure, local variation in velocity and kinetic energy profile in the airway.

Effect of transient inhalation on powder evacuation and dispersion in a typical dual air inlet dry powder inhaler

An optically accessible research dry powder inhaler (DPI) was used to investigate the impact of initial acceleration during inhalation on the powder evacuation and drug dispersion processes. The inhaler featured a swirling chamber connected with two inlets, closely resembling commercial devices such as the Aerolizer® and Osmohaler®. The dimensions of the inhaler were kept similar to the commercial devices, mimicking their flow situations. High-speed microscopic imaging and an in-house developed image processing technique were used to extract relevant statistics. The current literature on DPI flow dynamics provides valuable insights into the correlation between inspiratory flow rate, peak inspiratory pressure, and inhaler performance. However, it lacks data correlating powder evacuation characteristics and deagglomeration mechanisms for transient inhalation conditions inside the DPIs. This paper is an attempt to fill this gap by investigating the evacuation pattern and deagglomeration mechanism for three different initial accelerations qualitatively representing asthma severity and steady-state inhalation conditions representing laminar, transitional, and turbulent channel flow, using both pure drug and carrier particles. The study's key findings revealed that powder evacuation progressed in two stages. The first stage was slow, with a slope ranging from 0.25 to 0.27. Also, the evacuation rate was independent of the initial inhalation acceleration. The second stage was rapid, with a slope ranging from 0.87 to 1.23, which led to faster and complete powder evacuation. The slow stage consumed approximately ∼60 % of the total evacuation time to evacuate only ∼20% of the loaded drug, while the rapid stage evacuated ∼80% of the powder in the remaining time. The data collected from these experiments advances the understanding of the DPI flow dynamics and provides high-quality data for validating computational models used in the analysis of such inhaler systems.

Investigating unsteady airflow characteristics in the human upper airway based on the clinical inspiration data

To enhance understanding of the airflow characteristics in the human respiratory system during realistic inspiration, we investigated the airflow field in a human upper airway model using large eddy simulation and the dynamic grid method, taking into account clinically measured inspiratory characteristics. The results reveal the following novel findings: (1) The laryngeal jet and recirculation zone exhibit significant unsteadiness, with their dynamic characteristics primarily influenced by the transient inspiration flow rate and glottis motion. This pattern holds true for other airflow characteristics as well. (2) Glottis expansion reduces the energy consumed during inhalation for both steady and unsteady inspiratory flow rates, with the degree of expansion being directly related to the reduction in energy. We can accurately predict power loss by considering the glottis area and inspiratory flow rate. (3) Analysis of spectral entropy clearly demonstrates that the flow transitions from the laminar to turbulence earlier when using clinical inspiration data. Turbulence intensity in the trachea increases when either glottis motion or the transient inspiratory is ignored. In conclusion, the airflow dynamics are significantly more unsteady compared to cases where we ignore either glottis motion or the transient inspiratory flow rate. A precise understanding of realistic respiratory airflow cannot be achieved by assuming either a rigid glottis or a steady inspiration pattern. Therefore, it is crucial to use accurate inspiratory data when studying the properties of airflow structures in the human respiratory system. Moreover, incorporating more physiological data is also essential to obtain realistic respiratory airflow characteristics.

Optimization of Vibrating Mesh Nebulizer Air Inlet Structure for Pulmonary Drug Delivery

The vibrating mesh nebulizer (VMN) has gained popularity for its compactness and noiselessness. This study investigates the impact of different air inlet structures on the deposition fraction (DF) of droplets generated by VMNs in an idealized mouth–throat (MT) airway model. Three homemade VMNs with semi-circular inlet, symmetrical four-inlet, and multiple-orifice inlet structures were evaluated through simulations and experiments. The changes in droplet DF of 0.9% w/v concentration of nebulized sodium chloride (NaCl) droplets as a function of inertial parameters were acquired under different inhalation flow conditions. Additionally, flow field distributions in models with different inlet structures were analyzed at a steady inspiratory flow rate of 15 L/min. The results indicate that optimizing the VMN’s air inlet structure significantly enhances droplet delivery efficiency. The multiple–orifice inlet structure outperformed the other designs, directing the airflow from the inlet position to the center of the mouthpiece and then into the oral cavity, achieving a DF of up to 20% at an inhalation flow rate of 15 L/min. The region of high airflow velocity between the mouthpiece and oral cavity proved to be a favorable VMN inlet optimization, reducing direct droplet–wall collisions and improving delivery efficiency. These findings offer insights for VMN design and optimization to enhance pulmonary drug delivery effectiveness and therapeutic outcomes.

Effects of vocal fold adduction on the particle deposition in the glottis: A numerical analysis and in vitro assessment

BackgroundThe efficacy of inhalation therapy depends on the drug deposition in the human respiratory tract. This study investigates the effects of vocal fold adduction on the particle deposition in the glottis. MethodsA realistic mouth-throat (MT) geometry was built based on CT images of a healthy adult (MT-A). Mild (MT-B) and great (MT-C) vocal fold (VF) adduction were incorporated in the original model. Monodisperse particles range in size from 3 to 12 μm were simulated at inspiration flow rates of 15, 30 and 45 L per minute (LPM). The regional deposition of drug aerosols was performed in 3D-printed models and quantified using high-performance liquid chromatography. ResultsBoth the numerical analysis and in vitro experiments show that most particles are deposited in the mouth, pharynx and supraglottis, while few are deposited in the glottis and subglottis. For most cases in MT-A, the particle quantity in glottis is lower than 0.02 N/mm2 at 15 and 30 LPM while they increase dramatically at 45 LPM. It peaked at 0.347 N/mm2 for 5-μm particles at 45 LPM in MT-B and 2.324 N/mm2 for 6-μm particles at 30 LPM in MT-C. The lowest drug mass faction in the glottis in vitro were found at 15 LPM for MT-A and MT-C, and at 30 LPM for MT-B, whereas it peaked at 45 LPM for all MT models, 0.71% in MT-A, 1.16% in MT-B, and 2.53% in MT-C, respectively. ConclusionBased on the results of this study, larger particles are more likely to be deposited in the oral cavity, oropharynx, and supraglottis than in the glottis. However, particle deposition in the glottis generally increases with VF adduction and greater inspiratory flow rates.

A novel experimental approach to measure nebulized droplet deposition pattern and deposition fraction in an idealized mouth-to-throat model

Accurate measurement of droplet/particle deposition fraction and spatial distribution is vital for understanding various inhalation processes, including nebulized therapy, inhalation of atmospheric pollutants, and exposure risk assessment to aerosols such as airborne SARS-COV-2-laden droplets. This paper presents a novel method to measure the deposition fraction and spatial distribution of the deposited particulate phase (i.e., deposition pattern) of droplets through a single experiment. The experiment employs an idealized mouth-to-throat model as a test platform for two vibrating mesh nebulizers to deposit droplets. By utilizing a nebulized solution of normal saline containing the fluorescein, the qualitative observation of droplet deposition pattern on the internal surfaces is achieved under ultraviolet excitation. Furthermore, through rinsing the experimental components and quantitatively determining the deposition fraction based on rinsate absorbance, experimental results indicate that the deposition fraction of nebulized droplets decreases initially and then increases with increasing inspiratory flow rate from 15 to 60 l/min. Additionally, the deposition hotspots gradually shift from the bottom of the oral cavity to the throat as the inhalation flow rate increases. In addition to providing validation data for the transport and deposition of high-concentration droplets, this experimental method has the potential for extension to research on aerosol transmission and exposure risk assessment. It offers valuable insight into the behavior of nebulized droplets, aiding in developing effective strategies for aerosolized therapies and mitigating transmission risks in various applications.

Evaluation of Peak Inspiratory Flow Rate in Hospitalized Palliative Care Patients with COPD.

Dry powder inhalers are an effective yet costly COPD medication-delivery device. Patients must possess a minimum peak inspiratory flow rate (PIFR) for inhaled medication to be properly deposited into the lungs. Hospitalized palliative-care patients with diminished lung function due to advanced COPD may not possess the minimum PIFR (30 L/min) for adequate drug delivery. This study aims to quantify PIFR values for hospitalized palliative-care patients with advanced COPD to evaluate whether these patients meet the minimum PIFR requirements. Hospitalized patients ≥18 years old with a palliative-care consultation were eligible if they had a diagnosis of advanced COPD (GOLD C or D). Patients were excluded if they lacked decision-making capacity or had a positive COVID-19 test within the previous 90 days. Three PIFR values were recorded utilizing the In-CheckTM device, with the highest of the three PIFR attempts being utilized for statistical analysis. Eighteen patients were enrolled, and the mean of the highest PIFR readings was 72.5 L/min (±29 L/min). Post hoc analysis indicated 99.9% power when comparing the average best PIFR to the minimum PIFR (30 L/min) but only 51.4% power when compared to the optimal PIFR (60 L/min). This study found that palliative-care patients possess the minimum PIFR for DPI drug delivery.

Large eddy simulation study of the airflow characteristics in a human whole-lung airway model

Studying airflow characteristics in the human respiratory system is important for understanding the properties of the aerosol transport and deposition. This study first constructed a human whole-lung airway model (WLAM) with random features extending from the mouth to the 13th generation bronchus. The large eddy simulation method is utilized to investigate the features of both the averaged airflow fields and flow unsteadiness under inspiratory flow rates of 15 and 30 l/min, respectively. The results reveal the following novel findings: (1) secondary flow strength is not monotonically changing throughout the respiratory tract, depending on the local flow state and geometry, which allows for strong secondary flow motion even in the G13 bronchial airway. (2) In the upper airway, the peak distribution of turbulent kinetic energy (TKE) is due to in-plane secondary flow shear and longitudinal flow shear; local kinetic energy plays a vital role in the persistence of unsteadiness throughout the bronchial tree, which allows instability to still exist even in the bronchial airway with low Reynolds number. (3) TI is more dependent on the local flow state and geometric structure than TKE. These findings indicate that secondary flow and airflow unsteadiness in the thin bronchial airway are far stronger than previously reported and cannot be neglected. Therefore, further studies should investigate airflow unsteadiness in the thin bronchial airway using a suitable WLAM instead of a segmented bronchial airway model.

Comparison of Effects of Liuzijue Exercise and Conventional Respiratory Training on Patients after Cardiac Surgery: A Randomized Controlled Trial.

To evaluate the feasibility and safety of Liuzijue exercise (LE) for the clinical effect in patients after cardiac surgery. Totally 120 patients who underwent cardiac surgery and were admitted to the Cardiothoracic Intensive Care Unit of Nanjing Drum Tower Hospital between July and Oclober, 2022 were allocated to the LE group, the conventional respiratory training (CRT) group, and the control group by a random number table at a ratio of 1:1:1; 40 patients in each group. All patients received routine treatment and cardiac rehabilitation. LE group and CRT group respectively performed LE and CRT once a day for 30 min for 7 days. Control group did not receive specialized respiratory training. The forced vital capacity, forced expiratory volume in 1 s, peak inspiratory flow rate, peak expiratory flow rate, maximum inspiratory pressure, maximum expiratory pressure, modified Barthel index (MBI), and Hamilton Rating Scale for Anxiety (HAM-A) were evaluated before, after 3 and 7 days of intervention. In addition, the postoperative length of hospital stay (LOS) and the adverse events that occurred during the intervention period were compared. A total of 107 patients completed the study, 120 patients were included in the analysis. After 3 days of intervention, the pulmonary function, respiratory muscle strength, MBI and HAM-A of all 3 groups improved compared with that before the intervention (P<0.05 or P<0.01). Compared with the control group, pulmonary function and respiratory muscle strength were significantly improved in the CRT and LE groups (P<0.05 or P<0.01). MBI and HAM-A were significantly improved in the LE group compared with the control and CRT groups (P<0.05 or P<0.01). On the 7th day after intervention, the difference was still statistically significant (P<0.01), and was significantly different from that on the 3rd day (P<0.05 or P<0.01). In addition, on the 7th day of intervention, the pulmonary function and respiratory muscle strength in the LE group were significantly improved compared with those in the CRT group (P<0.01). MBI and HAM-A were significantly improved in the CRT group compared with the control group (P<0.01). There were no significant differences in postoperative LOS among the 3 groups (P>0.05). No training-related adverse events occurred during the intervention period. LE is safe and feasible for improving pulmonary function, respiratory muscle strength, the ability to complete activities of daily living and for relieving anxiety of patients after cardiac surgery (Registration No. ChiCTR2200062964).

Ultrasound -guided erector spinae plane block (ESPB) versus intravenous opioids based analgesia in patients with rib fractures

ABSTRACT Background There has been a great interest in the erector spinae plane block (ESPB) to control pain in patients who are presented with rib fractures. ESPB has been shown to achieve adequate analgesia with little adverse effects, although its effectiveness in comparison to other analgesic alternatives has not been sufficiently studied. Aim of the study Our target was to compare the effectiveness of ESPB and opioid based analgesia in relieving pain in rib fractures patients. Methodology Fifty-two patients between 21 and 60 years old, divided into 2 equal groups, received either Ultrasound-guided (US) ESPB with 20 ml of bupivacaine 0.25% or intravenous (IV) morphine 0.1 mg/kg then IV Patient-controlled analgesia (PCA) containing morphine. Assessment of visual analogue scale (VAS) score before and after spirometer exercise at baseline, then at 30 minutes, 6 hours, and 12 hours after the intervention was done. Also Peak Inspiratory Flow Rate (PIFR) was measured by an incentive spirometer, first 12-hour morphine consumption as rescue analgesia was calculated, the incidence of complications was noted, and patients satisfaction was assessed. Results The VAS score was higher in morphine group compared to ESPB group before and after spirometry. PIFR was higher in ESPB group. Less opioid consumption and side effects, along with better patient satisfaction, were recorded in the ESPB group. Conclusion Erector spinae plane block provided superior analgesia and improved respiratory function for IV PCA morphine. Furthermore, ESPB was linked to fewer side effects, less opioid use, and better patient satisfaction.

Effect of Inhalation Profile on Delivery of Treprostinil Palmitil Inhalation Powder.

Treprostinil palmitil (TP), a prodrug of treprostinil, is being developed as an inhalation powder (TPIP) for the treatment of patients with pulmonary arterial hypertension (PAH) and pulmonary hypertension due to interstitial lung disease (PH-ILD). In ongoing human clinical trials, TPIP is administered via a commercially available high resistance (HR) RS01 capsule-based dry powder inhaler (DPI) device manufactured by Berry Global (formerly Plastiape), which utilizes the patient's inspiratory flow to provide the required energy to deagglomerate and disperse the powder for delivery to their lungs. In this study, we characterized the aerosol performance of TPIP in response to changes in inhalation profiles to model more realistic use scenarios, i.e., for reduced inspiratory volumes and with inhalation acceleration rates that differ from those described in the compendia. The emitted dose of TP for all combinations of inhalation profiles and volumes ranged narrowly between 79 and 89% for the 16 and 32 mg TPIP capsules at the 60 LPM inspiratory flow rate but was reduced to 72-76% for the 16 mg TPIP capsule under the scenarios at the 30 LPM peak inspiratory flow rate. There were no meaningful differences in the fine particle dose (FPD) at all conditions at 60 LPM with the 4 L inhalation volume. The FPD values for the 16 mg TPIP capsule ranged narrowly between 60 and 65% of the loaded dose for all inhalation ramp rates with a 4 L volume and at both extremes of ramp rates for inhalation volumes down to 1 L, while the FPD values for the 32 mg TPIP capsule ranged between 53 and 65% of the loaded dose for all inhalation ramp rates with a 4 L volume and at both extremes of ramp rates for inhalation volumes down to 1 L for the 60 LPM flow rate. At the 30 LPM peak flow rate, the FPD values for the 16 mg TPIP capsule ranged narrowly between 54 and 58% of the loaded dose at both extremes of the ramp rates for inhalation volumes down to 1 L. Based on these in vitro findings, the TPIP delivery system appears not to be affected by the changes in inspiratory flow profiles or inspiratory volumes that might be expected to occur in patients with PAH or PH associated with underlying lung conditions such as ILD.

Computational fluid dynamics model of laryngotracheal stenosis and correlation to pulmonary function measures

3D models of airway lumens were created from CT scans of 19 patients with laryngotracheal stenosis. Computational fluid dynamics (CFD) simulations were completed for each, and results were compared to measured peak inspiratory flow rate, grade of lumen constriction, and measures of airway geometry. Results demonstrate flow resistance and shear stress correlate with degree of lumen constriction and absolute cross-sectional area as well as flow rate. Flow recirculation depends on airway constriction but does not vary with flow rate. Resistance and wall shear stress did not correlate well with functional measures. Flow recirculation did differ between subjects with higher functional measures and subjects with lower functional measures. This analysis provides mathematical models to predict airway resistance, wall shear stress, and flow reversal according lumen constriction and inspiratory flow rate. It suggests aerodynamic factors such as flow recirculation play a role in differences in functional performance between patients with similar airway measures.