Reply from David P. Burns, Eric F. Lucking and Ken D. O'Halloran: Auxiliary compensation for diaphragm dysfunction in dystrophic disease

Keratoconus is a dystrophic disease of the cornea, when it is thinned with the formation of a conus-like protrusion (protrusion of the cornea). This disease belongs to the group of keratectasia, it has a multifactorial nature and occurs in approximately 25 % of all corneal pathologies. The disease can be either primary, which is based on dystrophic changes in the cornea, or secondary, which develops against the background of prenatal keratitis. Keratoconus of iatrogenic origin, which develops as a result of refractive eye microsurgery, has become widespread during the last 20 years. Most often primary keratoconus manifests during puberty, progresses to 30–40 years, after which its development slows down. An early clinical manifestation of this corneal pathology is a progressive decrease in visual acuity, development of double vision (binocular diplopia) with the development of a strong headache against this background. Monocular polyopia — images and symbols with multiple contours — develops subsequently. Severe dry eyes, itching, photophobia appear in advanced stages. Diagnosis of keratoconus in some cases can be a significant difficulty, since the use of conventional research methods only allow to suspect refractive errors in the form of myopia or astigmatism. It is necessary to take into account the impossibility of correcting visual impairment using conventional methods — glasses or contact lenses — to make correct diagnosis. As a rule, diagnosis of keratoconus requires use of expanded spectrum of instrumental research methods.

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Ventilator Weaning

10.2310/tywc.8364 ◽

2018 ◽

Author(s):

Brian Brajcich ◽

Ann Hwalek ◽

Joseph Posluszny

Keyword(s):

Respiratory Mechanics ◽

Spontaneous Breathing Trial ◽

Clinical Status ◽

Ventilator Weaning ◽

Evidence Based ◽

Airway Patency ◽

Diaphragm Dysfunction ◽

Complex Process ◽

Abcde Bundle ◽

Based Medicine

Ventilator weaning/liberation is a complex process that requires focus on a patient’s respiratory mechanics, strength, awareness, airway patency, and secretions while also keeping in mind a patient’s overall clinical status and critical illness. The recommendations in the chapter are based on evidence-based medicine when available. When no clear data can definitively guide patient management, clinical guidelines and accepted practices are described. Our hope is that the reader finds this chapter as a reliable and safe way to approach ventilator liberation. This review contains 4 figures, 6 tables and 77 references Key Words: ABCDE bundle, diaphragm dysfunction, negative inspiratory force, reintubation, RSBI, sedation, spontaneous breathing trial, tracheostomy, ventilator liberation, ventilator weaning

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Ventilator-induced diaphragm dysfunction in critical illness

Experimental Biology and Medicine ◽

10.1177/1535370218811950 ◽

2018 ◽

Vol 243 (17-18) ◽

pp. 1331-1339 ◽

Cited By ~ 3

Author(s):

Yung-Yang Liu ◽

Li-Fu Li

Keyword(s):

Oxidative Stress ◽

Mechanical Ventilation ◽

Muscle Atrophy ◽

Structural Damage ◽

Molecular Mechanisms ◽

Substantial Reduction ◽

Mechanical Stretch ◽

Janus Kinase ◽

Diaphragm Muscle ◽

Diaphragm Dysfunction

Mechanical ventilation is an essential intervention for intensive care unit patients with acute lung injury. However, the use of controlled mechanical ventilation in both animal and human models causes ventilator-induced diaphragm dysfunction, wherein a substantial reduction in diaphragmatic force-generating capacity occurs, along with structural injury and atrophy of diaphragm muscle fibers. Although diaphragm dysfunction, noted in most mechanically ventilated patients, is correlated with poor clinical outcome, the specific pathophysiology underlying ventilator-induced diaphragm dysfunction requires further elucidation. Numerous factors may underlie this condition in humans as well as animals, such as increased oxidative stress, calcium-activated calpain and caspase-3, the ubiquitin–proteasome system, autophagy–lysosomal pathway, and proapoptotic proteins. All these alter protein synthesis and degradation, thus resulting in muscle atrophy and impaired contractility and compromising oxidative phosphorylation and upregulating glycolysis associated with impaired mitochondrial function. Furthermore, infection combined with mechanical stretch may induce multisystem organ failure and render the diaphragm more sensitive to ventilator-induced diaphragm dysfunction. Herein, several major cellular mechanisms associated with autophagy, apoptosis, and mitochondrial biogenesis—including toll-like receptor 4, nuclear factor-κB, Src, class O of forkhead box, signal transducer and activator of transcription 3, and Janus kinase—are reviewed. In addition, we discuss the potential therapeutic strategies used to ameliorate ventilator-induced diaphragm dysfunction and thus prevent delay in the management of patients under prolonged duration of mechanical ventilation. Impact statement Mechanical ventilation (MV) is life-saving for patients with acute respiratory failure but also causes difficult liberation of patients from ventilator due to rapid decrease of diaphragm muscle endurance and strength, which is termed ventilator-induced diaphragmatic damage (VIDD). Numerous studies have revealed that VIDD could increase extubation failure, ICU stay, ICU mortality, and healthcare expenditures. However, the mechanisms of VIDD, potentially involving a multistep process including muscle atrophy, oxidative loads, structural damage, and muscle fiber remodeling, are not fully elucidated. Further research is necessary to unravel mechanistic framework for understanding the molecular mechanisms underlying VIDD, especially mitochondrial dysfunction and increased mitochondrial oxidative stress, and develop better MV strategies, rehabilitative programs, and pharmacologic agents to translate this knowledge into clinical benefits.

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ORTHOPAEDIC ASPECTS OF SURGICAL TREATMENT OF PATIENTS WITH DEGENERATIVE-DYSTROPHIC DAMAGE OF THE LUMBOSACRAL SPINE

Hirurgiâ pozvonočnika ◽

10.14531/ss2005.3.61-70 ◽

2005 ◽

pp. 061-070

Author(s):

Vladimir Mikhailovich Shapovalov ◽

Aleksandr Kaisinovich Dulaev ◽

Yury Alekseyevich Shulev ◽

Vladimir Petrovich Orlov ◽

Konstantin Alekseyevich Nadulich ◽

...

Keyword(s):

Treatment Outcome ◽

Clinical Practice ◽

Surgical Treatment ◽

Spinal Stenosis ◽

Functional Results ◽

Surgical Approaches ◽

Lumbosacral Spine ◽

Suggested Approach ◽

Modern Level ◽

Dystrophic Disease

Objective. On the basis of clinical and anatomico-functional results of surgical treatment of patients with degenerativedystrophic disease of the lumbosacral spine to develop and introduce into clinical practice orthopaedic surgical approaches aimed mainly to the correction and stabilization of the spine. Materials and Methods. The results of surgical treatment of 340 patients operated on for degeneconventionally and by the technique proposed by authors with the account for orthopaedic factors rative-dystrophic disease of the lumbosacral spine were analyzed. Results. The treatment outcome was mainly influenced by the following factors: spinal stenosis, instability and lumbosacral shape (balance) disturbance. The pattern of preopreative planning was developed on the basis of the introduced comprehensive methods of diagnosis. The suggested approach to surgical treatment has gone through clinical approbation resulted in recommendations for its application in practice. The paper presents the advantages of use of modern neuroorthopaedic technologies for various forms of spinal stenosis, and orthopaedic correction techniques in patients with discogenic radiculopathy associated with instability and deformity of the lumbosacral spine. Conclusion. The modern level of neuroorthopaedic care suggests new approaches to diagnosis and surgical management of patients with degenerative-dystrophic disease of the lumbosacral spine.

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Attenuation of ventilation-induced diaphragm dysfunction through toll-like receptor 4 and nuclear factor-κB in a murine endotoxemia model

Laboratory Investigation ◽

10.1038/s41374-018-0081-0 ◽

2018 ◽

Vol 98 (9) ◽

pp. 1170-1183 ◽

Cited By ~ 9

Author(s):

Li-Fu Li ◽

Yung-Yang Liu ◽

Ning-Hung Chen ◽

Yen-Huey Chen ◽

Chung-Chi Huang ◽

...

Keyword(s):

Nuclear Factor Κb ◽

Nuclear Factor ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Diaphragm Dysfunction ◽

Endotoxemia Model

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Ventilator-induced diaphragm dysfunction: the clinical relevance of animal models

Applied Physiology in Intensive Care Medicine 2 ◽

10.1007/978-3-642-28233-1_20 ◽

2012 ◽

pp. 197-206

Author(s):

Theodoros Vassilakopoulos

Keyword(s):

Animal Models ◽

Clinical Relevance ◽

Diaphragm Dysfunction

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Comparative Efficacy of Angiotensin II Type 1 Receptor Blockers Against Ventilator‐Induced Diaphragm Dysfunction in Rats

Clinical and Translational Science ◽

10.1111/cts.12916 ◽

2020 ◽

Author(s):

Stephanie E. Hall ◽

Bumsoo Ahn ◽

Ashley J. Smuder ◽

Aaron B. Morton ◽

J. Matthew Hinkley ◽

...

Keyword(s):

Angiotensin Ii ◽

Comparative Efficacy ◽

Diaphragm Dysfunction ◽

Receptor Blockers

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Assessment of diaphragm dysfunction during cardiac rehabilitation after heart surgery: the role of ultrasound imaging

European Heart Journal ◽

10.1093/ehjci/ehaa946.3086 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

F Maranta ◽

V Rizza ◽

I Cartella ◽

S Pellegrino ◽

A Bonaccorso ◽

...

Keyword(s):

Cardiac Surgery ◽

Functional Recovery ◽

Heart Surgery ◽

Respiratory Cycle ◽

Invasive Technique ◽

Valve Repair ◽

Combined Surgery ◽

Diaphragm Dysfunction ◽

Diaphragm Function ◽

The Right

Abstract Background Diaphragm dysfunction is a frequent and underdiagnosed complication of cardiac surgery. It can cause dyspnoea, decreased exercise performance and, in more severe cases, respiratory failure. Ultrasonography (US) is a valuable, non-invasive technique for the assessment of diaphragm function. Only few trials have been conducted using US to evaluate diaphragm functional recovery after cardiovascular rehabilitation (CR). Purpose The aim of the study was to assess with US the incidence of diaphragm dysfunction after heart surgery and to define the impact of an inpatient CR programme on diaphragm functional recovery. Methods We performed a single-centre prospective cohort study, enrolling 185 patients hospitalized in our CR unit: 99 patients underwent mitral valve repair or replacement, 28 tricuspid valve repair or replacement, 53 aortic valve replacement, 30 coronary artery bypass grafting, 59 combined surgery and 14 other surgical procedures. Diaphragm US was performed at admission and after 10 rehabilitative sessions. We assess the following parameters on quiet breathing: excursion, time of inspiration, time of a respiratory cycle and contraction velocity (slope) in M-mode on the right anterior subcostal projections and thickening fraction (TF) in B-mode on the right intercostal projections. TF was defined as [(thickness at end inspiration–thickness at end expiration)/thickness at end expiration]. Results The median excursion at admission was 1.6 cm. Patients with excursion <2 cm (lower limit for the general population) were considered with diaphragm dysfunction. Following cardiac surgery, the incidence of diaphragm dysfunction was 70.8%. Patients with excursion <2 cm at admission gained an important benefit from CR, with a significant improvement in TF (p<0.001), excursion (p<0.001), time of inspiration (p<0.001), time of a respiratory cycle (p<0.001) and slope (p<0.001). Conversely, in patients with excursion ≥2 cm there was no significant improvement in slope (p=0.539) and excursion (p=0.179). At the final assessment, diaphragm function recovered in 50.5% of the patients, whilst 49.5% had a failure of recovery (excursion relative change between admission and discharge <33%). The multivariate analysis identified combined surgery (OR 3.08; 95% CI 1.59–5.99, p=0.001) and post-surgical pneumothorax (OR 3.05; 95% CI 1.23–7.55, p=0.036) as independent predictors of failure of diaphragm function recovery. Conclusions US might be a valuable tool for initial and follow-up assessment of patients after cardiac surgery. CR has been shown to be an effective strategy to improve diaphragm parameters in patients with post-surgical dysfunction. Patients undergoing combined surgery or developing post-surgical pneumothorax might benefit from a personalised rehabilitation programme to improve diaphragm function. Funding Acknowledgement Type of funding source: None

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