Respiratory Involvement In Patients Research Articles

Sound-based cough peak flow estimation in patients with neuromuscular disorders.

Cough impairment is common in individuals with neuromuscular disorders and is associated with respiratory infections and shorter survival. Cough strength is assessed by measuring cough peak flow (CPF) using a flow meter, but this method requires a complex device setup and trained staff. The aim of the study is to evaluate the reliability of a smartphone app to estimate CPF based on cough sounds in a cohort of individuals with neuromuscular disorders. Individuals with neuromuscular disorders underwent CPF measurement with a flow meter and a smartphone app. A CPF <270 L/min was considered abnormal. Of the 50 patients studied, 26 had amyotrophic lateral sclerosis (52%), 15 had hereditary myopathies (30%), and 9 had myasthenia gravis (18%). The intraclass correlation coefficient (ICC) between the CPF measured with a flow meter and CPF estimated with cough sounds was 0.774 (p < .001) even if the patients had orofacial weakness (ICC = 0.806, p < .001). The smartphone app had 94.4% sensitivity and 100% specificity to detect patients with CPF of less than 270 L/min. Our findings suggest that sounds measured with a smartphone app provide a reliable estimate of CPF in patients with neuromuscular disorders, even in the presence of with orofacial weakness. This may be a convenient way to monitor respiratory involvement in patients with neuromuscular disorders, but larger studies of more diverse patient cohorts are needed.

Pulmonary Involvement in Neuromuscular Diseases: A Review.

Neuromuscular diseases (NMDs) affect muscle function directly or indirectly by affecting nerves or neuromuscular junctions. One of the leading causes of death in patients with NMD is respiratory muscle weakness (RMW). Respiratory involvement in patients with NMD can manifest widely, from mild failure that may initially affect only sleep to severe failure that can be life-threatening. Care approaches include arranged and precise clinical follow-ups of signs of sleep-disordered breathing, daytime hypoventilation, coughing, and swallowing disturbances. This manuscript will review the mechanisms and abnormalities of respiratory function in patients with NMD and help optimize NMD management.

Peak expiratory flow and the single-breath count test as markers of respiratory function in patients with myasthenia gravis

IntroductionMyasthenia gravis (MG) is an antibody-mediated autoimmune disease characterised by fluctuating, fatigable muscle weakness, frequently involving bulbar and respiratory muscles. Considering the severity of respiratory involvement in MG, routine evaluation of respiratory function is essential. The aim of this study was to identify a useful clinical marker of respiratory involvement in patients with MG. MethodsWe performed an observational study of patients with MG. All cases were evaluated with the single-breath count test, peak expiratory flow (PEF), a modified Medical Research Council dyspnoea scale (mMRC), and a neck strength assessment. The results of these parameters were correlated with forced vital capacity (FVC), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP). ResultsThe study included 45 patients with MG: 2 patients classified as grade I on the Myasthenia Gravis Foundation of America classification at the time of evaluation, 35 classified as grade II, 7 classified as grade III, and one classified as grade IV. Positive correlations were found between single-breath count test scores and FVC values (r = 0.57, P = .000), and between PEF and FVC values (r = 0.76, P = .000). Severity of dyspnoea according to the mMRC scale showed a negative correlation with FVC values (r = -0.31, P = .03). PEF also showed a significant correlation with MEP (r = 0.51, P = .002). ConclusionsPEF, the single-breath count test, and the mMRC scale are useful measures for evaluating respiratory function in patients with MG.

Outcomes of patients presenting with Guillain-Barre Syndrome at a tertiary care center in India

BackgroundThe Guillain-Barre Syndrome (GBS), also known as acute idiopathic polyneuritis, is a critical acquired condition associated with preceding nonspecific infection or triggering factors like trauma, surgery, or vaccination. GBS is currently the most frequent cause of acute flaccid paralysis in India. This study evaluates the short-term and in-hospital outcomes in different subtypes of GBS.MethodsA prospective observational study was conducted at V.S. Hospital, Ahmedabad, from September 2015 to December 2017. Patients above the age of 12 were included. Patients having other underlying neurological conditions, as well as immunodeficiency disorders, were excluded. The patients were classified into different subtypes of GBS, and functional outcomes were recorded on admission and discharge according to Hughes Scoring System. All statistical analyses were performed by using SPSS software.ResultsOut of 50 patients, 35 (70%) were males. The mean age was of 37.18 +/− 18.35 years. 25 (50%) patients had a preceding infection. 88% of patients presented with cranial nerve (CN) involvement had a Hughes Score of >/= 3 (p = 0.0087). They had less improvement of Hughes Score on discharge (0.13 +/− 0.04) as compared to the patients without cranial nerve involvement (0.38 +/− 0.08) (p = 0.008). Respiratory involvement was associated with a higher Hughes Score (p = 0.005) on admission. 85% of patients diagnosed with an axonal subtype of GBS had a Hughes Score of >/= 3 (p = 0.06) compared to 74% patients with demyelinating subtype. Axonal subtype required double period (11 +/− 2.34) to show improvement as compared to demyelinating subtype (6 +/− 1.2) (p = 0.020). Irrespective of the subtypes, in two different treatment cohorts (PLEX vs IVIG), there was no difference in short term functional outcomes measured by improvement in the Hughes scores (p = 0.89).ConclusionsEarly cranial nerve and respiratory involvement in patients presenting with GBS are associated with poor outcomes warranting immediate critical care involvement. In our study, amongst all the subtypes, axonal had poor clinical outcomes. Further clinical trials on the Indian subpopulation will help us evaluate the impact of different treatment modalities on this disease.

Recurrent Pneumothoraces in a Patient with Emery Dreifuss Syndrome: A Case Report and Review of the Literature.

Emery Dreifuss Muscular Dystrophy (EDMD) is an inherited disorder which leads to progressive worsening of muscular function. In this report, we present a case of a 29 years old woman with EDMD who presented with sudden left anterior chest pain and was diagnosed with recurrent pneumothoraces. We will highlight how a patient with EDMD-related pneumothoraces can develop rapidly worsening ventilatory function resulting in acute hypercapnic respiratory failure. Patients with muscular dystrophies require a high level of acuity on part of the physician to predict. Physician should be on high alert when treating patients with EDMD and pneumothorax given the potential for rapid respiratory deterioration and the requirements of immediate ventilation support. Having the ability to predict the severity of respiratory involvement in patients with EDMD is a key for favorable outcomes, besides prognostication, it also allows physicians to develop an earlier interventional plan for management of potential respiratory failure. In this report, we also provide in-depth review regarding the approach to the assessment of respiratory function in patients with EDMD and the current literature on the management of respiratory complications seen in patients with EDMD, a highly vulnerable population.

El pico flujo espiratorio y la cuenta máxima son marcadores del compromiso respiratorio en la miastenia gravis

IntroductionMyasthenia gravis (MG) is an antibody-mediated autoimmune disease characterised by fluctuating, fatigable muscle weakness, frequently involving bulbar and respiratory muscles. Considering the severity of respiratory involvement in MG, routine evaluation of respiratory function is essential.The aim of this study was to identify a useful clinical marker of respiratory involvement in patients with MG. MethodsWe performed an observational study of patients with MG. All cases were evaluated with the single-breath counting test, peak expiratory flow (PEF), a modified Medical Research Council dyspnoea scale (mMRC), and a neck strength assessment. The results of these parameters were correlated with forced vital capacity (FVC), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP). ResultsThe study included 45 patients with MG: 2 patients classified as grade I on the Myasthenia Gravis Foundation of America classification at the time of evaluation, 35 classified as grade II, 7 classified as grade III, and one classified as grade IV. Positive correlations were found between single-breath counting test scores and FVC values (r = 0.57, p = .000), and between PEF and FVC values (r = 0.76, p = .000). Severity of dyspnoea according to the mMRC scale showed a negative correlation with FVC values (r = -0.31, p = .03). PEF also showed a significant correlation with MEP (r = 0.51, p = .002). ConclusionsPEF, the single-breath counting test, and the mMRC scale are useful measures for evaluating respiratory function in patients with MG.

Coronavirus Disease 2019 and the Cerebrovascular-Cardiovascular Systems: What Do We Know So Far?

The severe acute respiratory syndrome coronavirus 2 pandemic of 2019 to 2020 has resulted in multiple hospitalizations, deaths, and economic hardships worldwide. Although respiratory involvement in patients with coronavirus disease 2019 (COVID‐19) is well known, the potential cardiovascular and cerebrovascular manifestations are less understood. We performed a PubMed and Google Scholar search and reviewed relevant literature on COVID‐19 and cardiovascular system involvement. Severe acute respiratory syndrome coronavirus 2 possesses high affinity for angiotensin‐converting enzyme 2 receptor, which is highly concentrated in the lungs and cardiovascular tissue, thereby provoking concern for cardiovascular involvement in COVID‐19 cases. Preexisting cardiovascular and cerebrovascular disease has been shown in previous reports to be a risk factor for severe infection. On the basis of our review of published studies, COVID‐19 patients may be more likely to experience acute cardiac injury, arrhythmia, coagulation defects, and acute stroke and are likely to have poorer outcomes as a result. As the COVID‐19 pandemic continues, more data about potential cardiovascular and cerebrovascular manifestations of the disease are required.

Compensatory Plasticity of Breathing in Patients with Neuromuscular Disease

Neuromuscular diseases are comprised of variable, often inherited conditions and characterized by muscular (e.g. Duchenne muscular dystrophy), neural (e.g. amyotrophic lateral sclerosis) or a mixed neuromuscular (e.g. Pompe disease) dysfunction. While individual neuromuscular disorders differ in the underlying mechanism and exhibit a unique disease presentation, the consistently leading cause of morbidity and mortality is respiratory failure. Loss of breathing function is literally a “life‐or‐death" issue for patients. Clinical management of breathing relies upon pulmonary function tests to estimate the degree of respiratory involvement in patients, but standard pulmonary function test results can be biased by learning, cognition, or poor effort. This presentation will discuss compensatory neuromuscular adaptations to preserve breathing in the face of worsening disease, including changes in neural drive, neuromuscular junction plasticity, and a greater reliance on less‐affected respiratory motor pools. Detection of these adaptations is needed for prescribing supportive therapies with greater precision and identifying clinically meaningful changes in response to treatments. Citing natural history studies from our team and others, this presentation will feature clinical approaches to objectively evaluate respiratory motor control and gain mechanistic insights into neuromuscular disease. The control of breathing will then be discussed in the context of clinical trials, with an emphasis on current and emerging treatments directed toward improvements in ventilation. Examples will highlight basic‐clinical collaborations that promote new therapeutic frontiers for patients with neuromuscular disease.Support or Funding InformationThis work is supported by National Institutes of Health awards R21 HD090752 and U01 HL121842.

Respiratory Involvement in Patients with Neuromuscular Diseases: A Narrative Review.

Respiratory muscle weakness is a major cause of morbidity and mortality in patients with neuromuscular diseases (NMDs). Respiratory involvement in NMDs can manifest broadly, ranging from milder insufficiency that may affect only sleep initially to severe insufficiency that can be life threatening. Patients with neuromuscular diseases exhibit very often sleep-disordered breathing, which is frequently overlooked until symptoms become more severe leading to irreversible respiratory failure necessitating noninvasive ventilation (NIV) or even tracheostomy. Close monitoring of respiratory function and sleep evaluation is currently the standard of care. Early recognition of sleep disturbances and initiation of NIV can improve the quality of life and prolong survival. This review discusses the respiratory impairment during sleep in patients with NMDs, the diagnostic tools available for early recognition of sleep-disordered breathing and the therapeutic options available for overall respiratory management of patients with NMDs.

1676. Incidence and Outcomes of Pulmonary Involvement in Patients with Scrub Typhus: A Clinical Study from India

BackgroundScrub typhus is a tropical fever caused by orrientia tsutsugamushi and is probably the most under-recognized of all the febrile illnesses leading to hospitalization, especially in India. Although the most common presenting symptoms are fever, myalgia, lymphadenopathy and rash, a significant percentage of patients also present with respiratory complaints.MethodsDecember 2018 at a tertiary care center, in Delhi, India. The primary objective was to determine the incidence of respiratory involvement in patients with scrub typhus on the basis of radiological findings. Secondary objective was to compare the length of hospital stay, clinical presentation, and severity of illness as indicated by transaminitis, thrombocytopenia, inotropic requirement, and lactate levels. Also compared was the difference in mortality between the two groups.ResultsPulmonary involvement was seen in 28.9% (22/76) patients which included varied radiological pictures. 5 patients required mechanical and 2 noninvasive ventilation. Eschar was seen in 44.7% out of which 20 had pulmonary involvement. Patients with pulmonary involvement had a significantly greater length of hospital stay (5.82 days vs. 2.56, P < 0.001), more severe transaminitis (P < 0.001), thrombocytopenia (P < 0.001), hyperlactatemia (P < 0.001), higher ionotropic requirement (P < 0.001) and mortality (P = 0.006).ConclusionPulmonary involvement was seen in almost one-third of the patients with scrub typhus and was associated with higher morbidity and mortality. These patients were sicker, often required intensive care admissions, inotropic support, noninvasive and invasive mechanical ventilation and a significantly prolonged hospitalization. Chest radiographs should be a part of routine evaluation of all patients suspected to have scrub typhus. With such high pulmonary involvement, scrub typhus forms an important differential diagnosis in patients with lung infection residing in endemic areas and in those with a history of travel to such areasDisclosures All authors: No reported disclosures.

Diaphragm sniff ultrasound: Normal values, relationship with sniff nasal pressure and accuracy for predicting respiratory involvement in patients with neuromuscular disorders

BackgroundIn patients with neuromuscular disorders, assessment of respiratory function relies on forced vital capacity (FVC) measurements. Providing complementary respiratory outcomes may be useful for clinical trials. Diaphragm sniff ultrasound (US) is a noninvasive technique that can assess diaphragm function that may be affected in patients with neuromuscular disorders.PurposeWe aimed to provide normal values of sniff diaphragm ultrasound, to assess the relationship between sniff diaphragm US, vital capacity (VC) and sniff nasal pressure. Additionally, we aimed to evaluate the diagnostic accuracy of sniff diaphragm US for predicting restrictive pulmonary insufficiency.Materials and methodsWe included patients with neuromuscular disorders that had been tested with a sniff diaphragm US and functional respiratory tests. Healthy subjects were also included to obtain normal diaphragm sniff ultrasound. We performed diaphragm tissue Doppler imaging (TDI) and time movement (TM) diaphragm echography combined with sniff maneuver.ResultsA total of 89 patients with neuromuscular diseases and 27 healthy subjects were included in our study. In patients, the median age was 32 years [25; 50] and the median FVC was 34% of predicted [18; 55]. Sniff diaphragm motion using TM ultrasound was significantly associated with sniff nasal pressure, both for the right hemidiaphragm (r = 0.6 p <0.0001) and the left hemidiaphragm (r = 0.63 p = 0.0008). Right sniff peak TDI velocity was also significantly associated with FVC (r = 0.72, p<0.0001) and with sniff nasal pressure (r = 0.66 p<0.0001). Sniff diaphragm ultrasound using either TM mode or TDI displayed significant accuracy for predicting FVC<60% with an area under curve (AUC) reaching 0.93 (p<0.0001) for the right sniff diaphragm ultrasound in TM mode and 0.86 (p<0.001) for right peak diaphragm TDI velocity.ConclusionSniff diaphragm TM and TDI measures were significantly associated with sniff nasal pressure. Sniff diaphragm TM and TDI had a high level of accuracy to reveal respiratory involvement in patients with neuromuscular disorders. This technique is useful to assess and follow up diaphragm function in patients with neuromuscular disorders. It may be used as a respiratory outcome for clinical trials.

ID 210 – Overlapping respiratory neuromuscular dysfunction in a case of Lambert–Eaton syndrome

Background Respiratory failure is a multifactorial and common complication among patients with small cell lung cancer (SCLC). Phrenic nerve injury secondary to local invasion or diaphragmatic neuromuscular junction (NMJ) disorder associated to Lambert–Eaton Syndrome (LES) may occasionally be involved. Objective To report a case of diaphragmatic dysfunction secondary to combined phrenic nerve injury and presynaptic NMJ transmission failure in a 50-year-old man with SCLC. Methods/Results The electrophysiological findings fulfilled the criteria of and P/Q-type VGCC antibodies were highly positive (343 pmol/l). On admission, the phrenic nerve conduction studies disclosed a markedly reduced CMAP amplitude with postactivation facilitation on the right side. The response was absent on the left with profuse spontaneous activity on diaphragmatic needle EMG. Follow-up study reported favorable response to treatment with 3,4-diaminopyridin on the right side. No changes were observed on the left, suggesting a persistent phrenic nerve injury. Conclusions Respiratory electrophysiological studies are invaluable tools to distinguish between many possible causes of respiratory dysfunction in patients with lung cancer and should be routinely included as part of a diagnostic work up. Key message Neuromuscular respiratory involvement in patients with SCLC may be overlooked. Abnormally very low diaphragm CMAP amplitudes should arise suspicion for presynaptic NMJ disorder.

Longitudinal course of lung function and respiratory muscle strength in spinal muscular atrophy type 2 and 3

BackgroundSpinal muscular atrophy (SMA) is a common genetic disorder that causes severe hypotonia and weakness, and often fatal restrictive lung disease. The aim of the study was to describe the natural history of the respiratory involvement in patients with SMA type 2 and 3 in order to assess the relevance of the clinical classification and identify the parameters associated with the earliest and most rapid decline over time. MethodsThirty-one patients aged 3–21 years were followed over a 10-year period. Lung function, blood gases, respiratory mechanics and muscle strength with recording of oesogastric pressures were measured during routine follow-up. ResultsAt least two measurements were available in 16 patients (seven type 2 and nine type 3). Among all the volitional and non-volitional, invasive and non-invasive tests, forced vital capacity (FVC) and sniff nasal inspiratory pressure (SNIP) were shown to be the most informative parameters, showing lower values in SMA type 2, with however a similar rate of decline in patients with SMA type 2 and 3. ConclusionOur results confirm an earlier decline in lung and respiratory muscle function in patients classified as SMA type 2 as compared with patients classified as type 3. This decline can be assessed by two simple non-invasive tests, FVC and SNIP, with the last maneuver being feasible and reliable in the youngest children, underlying its interest for the monitoring of children with SMA.

24. The prevalence and characterization of respiratory involvement in patients with Hunter syndrome in the Hunter Outcome Survey

24. The prevalence and characterization of respiratory involvement in patients with Hunter syndrome in the Hunter Outcome Survey

Respiratory electrophysiological studies in Guillain-Barré syndrome.

Respiratory failure is a common and potentially life threatening complication in patients with Guillain-Barré syndrome. The incidence of phrenic nerve involvement and the predictive value of phrenic nerve conduction and diaphragmatic needle EMG were studied in 40 patients with Guillain-Barré syndrome within the first three days of admission to hospital. The negative peak onset latency of the diaphragmatic compound muscle action potential (CMAP), and its amplitude, duration, and area were abnormal in 83%. The need for ventilation was correlated with diaphragmatic CMAP amplitude (P = 0.005), and area (P = 0.001), but not with latency or duration. Abnormalities in diaphragmatic needle EMG were found in 45%, mainly a decreased number of motor unit potentials. The abnormalities correlated with the need for ventilation (P = 0.013). Of the 40% who required ventilation, all had either abnormal phrenic conduction, abnormal diaphragmatic needle EMG, or both. Eighty one per cent of the ventilated patients had abnormal forced vital capacity on the day of the electrophysiological examination. The results indicate that phrenic nerve conduction studies and diaphragmatic EMG are useful in detecting respiratory involvement in patients with Guillain-Barré syndrome and in identifying those at risk of respiratory failure.

The Lung in Inflammatory Bowel Disease†

Respiratory involvement in patients with inflammatory bowel disease (IBD) has been reported mainly since 1976. This form of involvement should clearly be separated from interstitial lung disease due to sulfasalazine or mesalamine, although the distinction may be difficult in some cases. We report the data of an ongoing Registry containing 33 cases (23 cases receiving no drug therapy) with ulcerative colitis or, less often, Crohn's disease, who developed varied bronchopulmonary problems. In several cases, the exact diagnosis and the relation of the bronchopulmonary disease to IBD had not been established for many years, thus delaying effective treatment with steroids. In most cases (28/33), respiratory involvement followed the onset of IBD (8 of these 28 cases were postcolectomy), and in the remainder, respiratory manifestations predated the IBD. Patterns of involvement included: 1) Airway inflammation, in the form of subglottic stenosis, chronic bronchitis, severe chronic bronchial suppuration, bronchiectasis, and chronic bronchiolitis. In cases with large airway involvement, endoscopy showed exuberant inflammatory tissue in the airways and narrowing of tracheal and/or bronchial lumen. Histologically, airways were heavily infiltrated by a dense aggregate of inflammatory cells, and there were mucosal ulcerations. 2) Varied patterns of interstitial lung disease, mainly bronchiolitis obliterans with organizing pneumonia, and pulmonary infiltrates and eosinophilia. (3) Miscellaneous other forms of involvement including striking neutrophilic necrotic parenchymal nodules (corresponding histologically to sterile aggregates of neutrophils), and serositis. Steroids were very effective in the majority of cases. Inhaled steroids were of durable benefit in patients with chronic bronchitis, but less often so in those with chronic bronchial suppuration, bronchiectasis, or chronic bronchiolitis. Steroids administered orally led to marked improvement in patients with interstitial lung disease and necrotic nodules, but lacked effectiveness in several patients with severe airway inflammation or chronic bronchiolitis. Intravenous steroids were required in the initial management of life-threatening complications such as asphyxiating subglottic stenosis or extensive interstitial lung disease. Bronchial lavages with methylprednisolone were effective in some patients with severe airway inflammation. Patients with IBD can develop varied inflammatory complications in the lung, and a sizable fraction of these complications is steroid-sensitive.