When the “piston” is Nonfunctioning

A 62-year-old woman with a history of hypertension, hypothyroidism, diabetes mellitus type 2, endometrial cancer after hysterectomy, and OSA underwent an elective total knee replacement. Her postoperative course was complicated by an esophageal food impaction requiring intubation for endoscopy, after which the patient developed postextubation bradycardia and hypoxemia in the setting of atrioventricular block and concern for flash pulmonary edema. The patient underwent a transthoracic echocardiogram, which revealed findings suggestive of acute cardiomyopathy with a negative ischemic workup. The ICU admission was complicated by recurrent left-sided atelectasis caused by mucous plugging resulting in multiple extubation failures despite aggressive pulmonary hygiene. Despite diuresis for pulmonary edema, the patient continued to report orthopnea and weak cough with inability to expectorate her sputum, and she continued to require supplemental oxygen. Further history obtained from the patient revealed progressive decline in her motor strength, worsening myalgias, and gait instability over the weeks preceding her initial admission. Neurologic examination was significant for proximal muscle weakness in the bilateral upper and lower extremities and hyperreflexia of the lower extremities. In the setting of suspected concurrent myopathy, the cardiomyopathy was attributed to myocarditis, and the patient received a permanent pacemaker for high-degree atrioventricular block. Laboratory evaluation revealed an erythrocyte sedimentation rate of 124 mm/h (normal, < 27 mm/h), C-reactive protein level of 17.7 mg/L (normal, 0-4.0 mg/L), and a creatine kinase level of 1,036 U/L (normal, 25-170 U/L). A bedside diaphragm ultrasound was performed (Videos 1, 2, 4, and 5). Question: What is the abnormality shown on the bedside diaphragm ultrasound (Videos 1 and 2 compared with Videos 4 and 5), and what is the most likely etiology of the recurrent unilateral mucous plugging and respiratory failure in this patient? Answer: The diaphragm ultrasound demonstrates weakness of the left hemidiaphragm, as evidenced by lack of exertion with both tidal and deep breathing in this patient (Videos 1 and 2), compared with a normal right hemidiaphragm (Videos 4 and 5). Use of M mode allows measurement of amplitude of excursion and calculation of diaphragm velocity, which are both markedly reduced. The bedside thoracic ultrasound is significant for unilateral left-sided diaphragmatic weakness with a large, simple pleural effusion. Based on the patient's clinical examination and history of progressive proximal muscle weakness, recent diagnosis of cardiomyopathy, and serologic evidence of muscle injury and systemic inflammation, a clinical diagnosis of inflammatory myopathy was made. Given the degree of involvement of the diaphragm and heart, the patient was empirically treated with high-dose corticosteroids and IV immunoglobulin. Results of further serologic testing revealed an antinuclear antibody titer of 1:1,280 and positive anti-Ku antibodies. The patient was ultimately diagnosed with connective tissue disease (CTD)-polymyositis overlap syndrome. Interestingly, she also developed recurrent left-sided exudative pleural effusion attributed to myositis and required placement of an indwelling pleural catheter. She had significant overall improvement in muscle weakness following initiation of therapy and was eventually titrated off supplemental oxygen therapy. Inflammatory myopathies are a heterogeneous group of CTD that can present with both muscular and extramuscular involvement. They can affect multiple organs, present in overlap syndromes, and have a wide range of severity. Myopathy in these patients with overlap syndromes may be subclinical or mild.1Tanboon J. Uruha A. Stenzel W. Nishino I. Where are we moving in the classification of idiopathic inflammatory myopathies?.Curr Opin Neurol. 2020; 33: 590-603Crossref PubMed Scopus (48) Google Scholar Pulmonary involvement in inflammatory myopathies is variable, and the frequency of involvement depends on the clinical entity. Interstitial lung disease is the most common manifestation of pulmonary involvement, although pleural and pulmonary vascular manifestations of disease have been described in the literature.2Lega J.C. Reynaud Q. Belot A. Fabien N. Durieu I. Cottin V. Idiopathic inflammatory myopathies and the lung.Eur Respir Rev. 2015; 24: 216-238Crossref PubMed Scopus (105) Google Scholar Anti-Ku antibodies are a type of myositis-associated autoantibodies implicated in multiple CTDs, including systemic sclerosis, systemic lupus erythematosus, mixed CTD, Sjogren syndrome, rheumatoid arthritis, undifferentiated CTD, and overlap syndromes.3Spielmann L. Nespola B. Severac F. et al.Anti-Ku syndrome with elevated CK and anti-Ku syndrome with anti-dsDNA are two distinct entities with different outcomes.Ann Rheum Dis. 2019; 78: 1101-1106Crossref Scopus (44) Google Scholar The presence of anti-Ku autoantibodies is most associated with undifferentiated CTD and overlap syndromes such as polymyositis, systemic sclerosis, and systemic lupus erythematosus. A higher frequency of interstitial lung disease has been observed in patients with anti-Ku autoantibodies and inflammatory myopathies-CTD. Patients with anti-Ku autoantibodies are more likely to fail to respond to corticosteroid treatments and require additional treatment with immunomodulating agents. Thus, anti-Ku autoantibodies can also be used for prognostication and prediction of treatment response. Involvement of the respiratory muscles and pleura is rare in inflammatory myopathies. Exudative pleural effusions can also occur in these patients. Although bilateral effusions may be attributable to this patient's concomitant cardiomyopathy, the exudative nature of the effusion suggests that the fluid may be inflammatory in nature. Moreover, the left-sided effusion was larger and rapidly reaccumulated, suggestive of an inflammatory cause for the effusion that correlates with left hemidiaphragm weakness. Cardiac involvement in dermatomyositis and polymyositis has been described, with an estimated prevalence between 9% and 72%.4Zhang L. Wang G.C. Ma L. Zu N. Cardiac involvement in adult polymyositis or dermatomyositis: a systematic review.Clin Cardiol. 2012; 35: 686-691PubMed Google Scholar Congestive heart failure due to left ventricular dysfunction is the most common clinical presentation and may result in pulmonary edema. Myocarditis can also occur and typically presents in conjunction with active muscular disease. Patients may also develop significant conduction blocks, supraventricular arrhythmias, or ventricular arrhythmias. Cardiac involvement in polymyositis and dermatomyositis has been reported as a poor prognostic factor, with increased mortality in both the acute and recovery phases of treatment. Ultrasound is a powerful tool for diagnosing underlying causes of respiratory failure through evaluation of the thoracic and cardiac systems. This evaluation begins with the phased array probe on the anterior chest, noting an A-line or B-line pattern. The phased array probe is next moved to the posterolateral alveolar and/or pleural syndrome (PLAPS) point.5Lichtenstein D.A. BLUE-protocol and FALLS-protocol: two applications of lung ultrasound in the critically ill.Chest. 2015; 147: 1659-1670Abstract Full Text Full Text PDF PubMed Scopus (356) Google Scholar At the PLAPS point, the diaphragm is noted on the right portion of the image with the lung located to the left of the image. The PLAPS point is where many pulmonary pathologies such as effusions, consolidations, and/or diaphragmatic dysfunction can be observed. Following completion of the lung ultrasound, a cardiac ultrasound is performed at the parasternal long axis, parasternal short axis, apical four chamber, and subcostal with inferior vena cava views. This combined lung and cardiac ultrasound can lead to more rapid diagnosis and treatment of etiology of respiratory failure in the critically ill with greater accuracy than traditional methodologies.6Wang X. Liu D. He H. et al.Using critical care chest ultrasonic examination in emergency consultation: a pilot study.Ultrasound Med Biol. 2015; 41: 401-406Abstract Full Text Full Text PDF PubMed Google Scholar Diaphragmatic function can be analyzed with ultrasound using both the B and M modes and either the phased or linear array transducers. Global evaluation of diaphragmatic excursion is usually screened at the PLAPS point by using the phased array transducer. A normally functioning diaphragm will contract with respiration, a term called diaphragmatic excursion. In this patient, there is reduction in diaphragmatic excursion on the left during tidal breathing (Video 1), and this reduction in diaphragmatic excursion persists during deep inspiration (Video 2). In contrast, there is normal diaphragmatic excursion on the right (Video 4). Diaphragmatic thickness is measured at end-inspiration and at end-expiration. The accepted lower limit of normal at end-expiration for diaphragmatic thickness is 1.3 mm in men and 1.1 mm in women.7Boussuges A. Rives S. Finance J. et al.Ultrasound assessment of diaphragm thickness and thickening: reference values and limits of normality when in a seated position.Front Med (Lausanne). 2021; 8742703Google Scholar M-mode evaluation of the diaphragm allows for measurement of thickness during the phases of respiration and calculation of velocity of contraction. Velocity of contraction is calculated as excursion of the diaphragm divided by the time to reach maximal excursion.8Turton P. Aidarous S.A.L. Welters I. A narrative review of diaphragm ultrasound to predict weaning from mechanical ventilation: where are we and where are we heading?.Ultrasound J. 2019; 11: 2Crossref Scopus (24) Google Scholar In this patient, M-mode evaluation of the diaphragm allows measurement of velocity of contraction at 4.0 cm per second on the left (Video 1, Part 2). In comparison, use of M mode on the right diaphragm allows measurement of velocity of contraction at 6.3 cm per second (Video 4, Part 2). A more detailed evaluation of diaphragmatic anatomy and function can be assessed by using the linear array transducer. The linear transducer is a higher-frequency transducer and is therefore ideal for a focused evaluation of diaphragm function. Higher resolution imaging permits measurement of thickness and function using both B and M modes. Grossly, B mode using the linear transducer demonstrates lack of movement of the left diaphragm (Video 3) compared with the right diaphragm (Video 5). Percent change in diaphragmatic thickness, or thickening fraction, is a described method to evaluate diaphragmatic function.9McCool F.D. Oyieng'o D.O. Koo P. The utility of diaphragm ultrasound in reducing time to extubation.Lung. 2020; 198: 499-505Crossref PubMed Scopus (9) Google Scholar Thickening fraction is calculated as end-inspiration thickness minus end-expiration thickness divided by the end-expiration thickness multiplied by 100. A thickening fraction < 20% to 30% is concerning for significant diaphragmatic dysfunction. M-mode evaluation of the diaphragm allows for measurement of thickness during the phases of respiration. Measurement of diaphragmatic thickness on the left (Video 3, Part 2) using M mode reveals a thickening fraction of 7.5, which was significantly reduced compared with the right (not shown). For the current study patient, a unifying diagnosis of inflammatory myositis was made in the presence of diaphragmatic weakness, recurrent inflammatory pleural effusion, cardiomyopathy, and proximal muscle weakness. The prognosis following initiation of therapy is favorable in these patients. Most patients have improvement or recovery of respiratory muscle function, as reported in longitudinal follow-up of a case series of patients with polymyositis/dermatomyositis.10Selva-O'Callaghan A. Labrador-Horrillo M. Munoz-Gall X. et al.Polymyositis/dermatomyositis-associated lung disease: analysis of a series of 81 patients.Lupus. 2005; 14: 534-542Crossref PubMed Scopus (0) Google Scholar Use of ultrasonography has a role in the identification of diaphragmatic weakness or paralysis and may be an important finding in critically ill patients. See Narration Video for a detailed explanation of Videos 1-5. 1.Use of ultrasonography to evaluate diaphragmatic function can be performed quickly at the bedside and allows for early recognition of diaphragmatic weakness or paralysis, which is underdiagnosed due to its nonspecific presentation.2.In patients with acute respiratory failure and evidence of inflammatory myopathies, evaluation of the diaphragmatic function may reveal weakness of the respiratory muscles.3.Point-of-care echocardiography can reveal evidence of cardiac involvement in inflammatory myopathies, a finding that has both treatment and prognostic implications. None declared. Other contributions: CHEST worked with the authors to ensure that the Journal policies on patient consent to report information were met. Additional information: Videos for this case are available under "Supplementary Data." eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiIxNzFhMjk3ZWRiZWExZTM2NTZiMGQwMWE0NmQzNjk4NSIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjg2MjM0MTM2fQ.mqhaqbtdlIN8t7ou7-VSxMBiUV1W_9DZcGoCl2sD34K-LF7MF_s1iIx3ElcRJRa1BjgwVXlednl3sqRw4E-Yi_lSgLI-5dtRUVRnteTSz8GqR2PB7lKDEvvfdARSYZWz-WfBMT5LYRiXTroL1gDm_tR2y6yTiLpv1YETmFtyRkMhWY1-UUsl7UaTMY_QShMBUXq7doO5L_7YdW4-x6jwPXyH0g_2xZL0RAdAAlqiRdKNenZHb2qMO42YNBPNLkp_7_gKJlH0X3UASYOJzE1ID5L0h6xwoxlO6jDHD6OzIWeUGzfJQ-sdXW86KMyAwXBqf2x0OBpW_Q83Wj6KjvU8rQ Download .mp4 (63.68 MB) Help with .mp4 files Video 1Left diaphragm tidal breathing. Part 1: The diaphragm ultrasound demonstrates significant weakness of the left hemidiaphragm, as evidenced by lack of excursion during normal breathing. Part 2: Use of M-mode through the left diaphragm allows for measurement of diaphragm velocity (A) equaling 4.0 cm per second.eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiJjYjVjYjkxZDkzNjdjMWExNjNlZjZmNDZmNTcyYmY0ZCIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjg2MjM0MTM2fQ.FsTqccRCc7Adg1bUPvD4vKOc8IAeuwnyUkpgZVUwdaA2fb7htECKr7PoeymOm2DV2aSNHdjBooby7qqI94rdl15RVa6dKZ1MU-9UbCsx6gz9J9Mb_ZcjSsSq-_LtZBtzCmZ6C8j1QdxdqXZGwi2Dx8POjlOnDloLrpnsrwhnapTiGK4Q0jpSwhkElWHELSSyOcaWXCuKVe6_LdJwn5w7q7W7XUSAbJYJV7zw-S3bAJM7Q3xetjL1EJxZhzLAk6WGxxu0SZbRsT9koJz9pLITRBp-E8RTrYG4ICjJA_AWxm2Cj7uhbH4s2wpDlLkNybTnCmLs5w2RKEdAauB2E80WAQ Download .mp4 (5.65 MB) Help with .mp4 files Video 2Left diaphragm deep breathing. The diaphragm ultrasound demonstrates weakness of the left hemidiaphragm with lack of excursion during deep breathing. Also visualized are the spleen, left kidney, and left ventricular cardiac contraction.eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiIzOWE2Y2QwZjVjMjJiZDRlYzE5ZGZkMTBmZDIzNzFiZSIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjg2MjM0MTM2fQ.akxunLWaaMbtCTciMzO-3AZiVIWFYb_vSRd4ku4b2aeaQSljoiLnJNuxgTy2GxEKKAU4ut9gPRqHLcZEPcJFOdIblad4On4gvXMZNo431TxWtpJIz9eidzl7FlrOquf54Y6gNlqmqcXKfr6YMMIGuweOFjUZ2lIH_cOyOsXVEqURHLFUpkP_yAJSneIBTcKOTcz4xZ2joY78e7wfKxkL0DmjChD0FczI_tVZyiCOSquWcLgMmQ_5A5aZb3vlt_puRwE4T58zC9q93H4WRrbJxuSdFjrqAWvUbzJem961a3BVHifuY_UYLGTwl-aR4SAmosbfPFf2ujCz38wX5xJEGA Download .mp4 (1.01 MB) Help with .mp4 files Video 3Left diaphragm detailed view and M mode. Part 1: Ultrasound of the left diaphragm demonstrates the presence of three distinct layers, with two echogenic layers of peritoneum and pleura on either side of the hypoechoic layer of muscle within. Again demonstrated is a lack of excursion with breathing. Part 2: Use of M mode through the left diaphragm allows for measurement of diaphragmatic thickness and determination of change of thickness during inspiration (A) and expiration (B). As shown, diaphragmatic thickness is noted to be 0.57 cm at end-inspiration and 0.53 cm at end-expiration, demonstrating no respiratory variation.eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiI0ZTRkNmU1NzhlNGZkNzUwMzk0M2IwYzhkZmFmNzJlZSIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjg2MjM0MTM2fQ.DfbZ33-VBQH10u7iaALozrDggFN1n8Hqpiao9CDd5Lmx0bCNl3EA6YsUxeLAcUpMVeEqUxdXSb7GoxP_QNsqPXYWPpQuN-ozXgGxWznRSYpRK-QudGrUCOUPZVAS7Dz2A-yjamr91irBrPBsiOH25RBRF7mftSfS6PL4d5Q2f-C3ujO2-tf5qgv0IEW5P240OD49KC4lNyc-XrKF0e6vkYIaV_iAxgMVKvRo_8ht3klnbXemNvUnUMQKRW2c5vAfF9ILx6KjGZSgZlSOIOKlxgZXKLZL4Z5va2X7YzO_GUbIpnmFJm4MWFZAIUC8lIQicxU_ZyBkZRqaIh5-RV48UA Download .mp4 (0.99 MB) Help with .mp4 files Video 4Right diaphragm tidal breathing. Part 1: Right hemithorax ultrasound demonstrates the presence of a moderate, simple pleural effusion with consolidated lung and normal diaphragmatic excursion with passive respiration. Part 2: Use of M mode through the right diaphragm allows for measurement of diaphragm velocity (A) equaling 6.3 cm per second.eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiI3ODM0YzMxOTJhZjlmNDY3NThkODhjZDg4MzQxM2ZkYiIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjg2MjM0MTM2fQ.lro37NZx8cSnAC3DISCnV2oS21J58hZbvaxEfvAiqScVCvuuf7xewP4ZHCvo9VwN2hB3PDmhaB5CxLEMMFi0nVY59jsPt8-_EWvbIa8I8av_Or_71Ec7jhxgsGrqVQTyZt73lK7DHcyeCnbJw1UFxlXy5Oc_SNBtZJZzay2Ut4V3gZ53aXszs5h2Eo4rSK9r6-Px6No6qo2J1TXXOUe7TL29dbsDD2x4WuGpYvwZKjt-a1Twd_JeiRzno3z934kMNWOFOUahIBdnAcYBPJtwmpyCHs-U43L2p1W9coN1Jg63dj-ip8orKUtvyfdR6Py7fi8BE-0WywsAUDvlF7mgDQ Download .mp4 (2.01 MB) Help with .mp4 files Video 5Right diaphragm detailed view. Contrast this video with Video 3. Ultrasound of the right diaphragm demonstrates again the presence of two echogenic layers with a central hypoechoic layer of muscle within and clear excursion of the diaphragm with passive breathing.eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiJkNTRjZTA4MTgyYTVkNTg2NTg4NTExM2UxNWE3ZmRjNyIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjg2MjM0MTM2fQ.h-yCvNNFWFv9IarwWB7wgRUgM-lmObHOpEGsJplzM_t8c5tH3MZrugaQwUOSSyyoXJxJnrv-g5RwVokIG-GQAcRWkD2KIl4H02PkkpuejWN42db6-kgZs57WQeWQM92P4cXwt-qetKcS1cSWgjA15UFTxPy4249INvRnCQBIZA-eAPKAuyQ1Ms_wobeqC2k7BLRejSOeD3SmgTq2HnVQnl6KDYb9erNdcXGrU8TPgEJiLArnrgOJ5Yk3epeNAjrKurZSyS6HuOA31PaW2FnQypzi1JSB27ZlIhOBgiGfGe-ZCRPfvqoriIQnyHLuYctjV5ie3qfnGwJxXhGdwsIM3A Download .mp4 (1.06 MB) Help with .mp4 files Video 6Discussion video.