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Critical Care
Published in: Critical Care 1/2016

Open Access 01-12-2016 | Review

Strategies to optimize respiratory muscle function in ICU patients

Authors: Willem-Jan M. Schellekens, Hieronymus W. H. van Hees, Jonne Doorduin, Lisanne H. Roesthuis, Gert Jan Scheffer, Johannes G. van der Hoeven, Leo M. A. Heunks

Published in: Critical Care | Issue 1/2016

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Abstract

Respiratory muscle dysfunction may develop rapidly in critically ill ventilated patients and is associated with increased morbidity, length of intensive care unit stay, costs, and mortality. This review briefly discusses the pathophysiology of respiratory muscle dysfunction in intensive care unit patients and then focuses on strategies that prevent the development of muscle weakness or, if weakness has developed, how respiratory muscle function may be improved. We propose a simple strategy for how these can be implemented in clinical care.
Literature
1.
Jaber S, Petrof BJ, Jung B, Chanques G, Berthet J-P, Rabuel C, et al. Rapidly progressive diaphragmatic weakness and injury during mechanical ventilation in humans. Am J Respir Crit Care Med. 2011;183:364–71.CrossRefPubMed
2.
Demoule A, Jung B, Prodanovic H, Molinari N, Chanques G, Coirault C, et al. Diaphragm dysfunction on admission to ICU: prevalence, risk factors and prognostic impact—a prospective study. Am J Respir Crit Care Med. 2013;188:213–9.CrossRefPubMed
3.
4.
Hooijman PE, Beishuizen A, de Waard MC, de Man FS, Vermeijden JW, Steenvoorde P, et al. Diaphragm fiber strength is reduced in critically ill patients and restored by a troponin activator. Am J Respir Crit Care Med. 2014;189:863–5.CrossRefPubMedPubMedCentral
5.
Adler D, Dupuis-Lozeron E, Richard JC, Janssens JP, Brochard L. Does inspiratory muscle dysfunction predict readmission after intensive care unit discharge? Am J Respir Crit Care Med. 2014;190:347–50.CrossRefPubMed
6.
Petrof B, Jaber S, Matecki S. Ventilator-induced diaphragmatic dysfunction. Curr Opin Crit Care. 2009;16(1):19–25.CrossRef
7.
Jaber S, Jung B, Matecki S, Petrof BJ. Clinical review: ventilator-induced diaphragmatic dysfunction—human studies confirm animal model findings! Crit Care. 2011;15:206.CrossRefPubMedPubMedCentral
8.
Jubran A, Tobin MJ. Pathophysiologic basis of acute respiratory distress in patients who fail a trial of weaning from mechanical ventilation. Am J Respir Crit Care Med. 1997;155:906–15.CrossRefPubMed
9.
Demoule A, Morelot-Panzini C, Prodanovic H, Cracco C, Mayaux J, Duguet A, et al. Identification of prolonged phrenic nerve conduction time in the ICU: magnetic versus electrical stimulation. Intensive Care Med. 2011;37:1962–8.CrossRefPubMed
10.
Levine S, Nguyen T, Taylor N, Friscia ME, Budak MT, Rothenberg P, et al. Rapid disuse atrophy of diaphragm fibers in mechanically ventilated humans. N Engl J Med. 2008;358:1327–35.CrossRefPubMed
11.
Hooijman PE, Beishuizen A, Witt CC, de Waard MC, Girbes AR, Spoelstra-de Man AM, et al. Diaphragm muscle fiber weakness and ubiquitin-proteasome activation in critically ill patients. Am J Respir Crit Care Med. 2015;191:1126–38.CrossRefPubMed
12.
Hussain SNA, Mofarrahi M, Sigala I, Kim HC, Vassilakopoulos T, Maltais F, et al. Mechanical ventilation-induced diaphragm disuse in humans triggers autophagy. Am J Respir Crit Care Med. 2010;182:1377–86.CrossRefPubMed
13.
Bloch S, Polkey MI, Griffiths M, Kemp P. Molecular mechanisms of intensive care unit-acquired weakness. Eur Respir J. 2012;39:1000–11.CrossRefPubMed
14.
Shanely RA, Van Gammeren D, Deruisseau KC, Zergeroglu AM, McKenzie MJ, Yarasheski KE, et al. Mechanical ventilation depresses protein synthesis in the rat diaphragm. Am J Respir Crit Care Med. 2004;170:994–9.CrossRefPubMed
15.
Thomas D, Maes K, Agten A, Heunks L, Dekhuijzen R, Decramer M, et al. Time course of diaphragm function recovery after controlled mechanical ventilation in rats. J Appl Physiol. 2013;115:775–84.CrossRefPubMedPubMedCentral
16.
van Hees HWH, Schellekens W-JM, Andrade Acuña GL, Linkels M, Hafmans T, Ottenheijm CAC, et al. Titin and diaphragm dysfunction in mechanically ventilated rats. Intensive Care Med. 2012;38:702–9.CrossRefPubMedPubMedCentral
17.
Callahan LA, Nethery D, Stofan D, DiMarco A, Supinski G. Free radical-induced contractile protein dysfunction in endotoxin-induced sepsis. Am J Respir Cell Mol Biol. 2001;24:210–7.CrossRefPubMed
18.
Powers SK, Hudson MB, Nelson WB, Talbert EE, Min K, Szeto HH, et al. Mitochondria-targeted antioxidants protect against mechanical ventilation-induced diaphragm weakness. Crit Care Med. 2011;39:1749–59.CrossRefPubMed
19.
Supinski GS, Callahan LA. Hemin prevents cardiac and diaphragm mitochondrial dysfunction in sepsis. Free Radic Biol Med. 2006;40:127–37.CrossRefPubMed
20.
Friedrich O, Reid MB, Van den Berghe G, Vanhorebeek I, Hermans G, Rich MM, et al. The sick and the weak: neuropathies/myopathies in the critically ill. Physiol Rev. 2015;95:1025–109.CrossRefPubMed
21.
Doorduin J, van Hees HWH, van der Hoeven JG, Heunks LMA. Monitoring of the respiratory muscles in the critically ill. Am J Respir Crit Care Med. 2012;185:90–5.CrossRefPubMed
22.
23.
Laghi F, Tobin MJ. Disorders of the respiratory muscles. Am J Respir Crit Care Med. 2003;168:10–48.CrossRefPubMed
24.
American Thoracic Society/European Respiratory Society. ATS/ERS Statement on respiratory muscle testing. Am J Respir Crit Care Med. 2002;166(4):518–624.CrossRef
25.
Caruso P, Friedrich C, Denari SD, Ruiz SA, Deheinzelin D. The unidirectional valve is the best method to determine maximal inspiratory pressure during weaning. Chest. 1999;115:1096–101.CrossRefPubMed
26.
Truwit JD, Marini JJ. Validation of a technique to assess maximal inspiratory pressure in poorly cooperative patients. Chest. 1992;102:1216–9.CrossRefPubMed
27.
28.
Akoumianaki E, Maggiore SM, Valenza F, Bellani G, Jubran A, Loring SH, et al. The application of esophageal pressure measurement in patients with respiratory failure. Am J Respir Crit Care Med. 2014;189:520–31.CrossRefPubMed
29.
30.
Goligher EC, Laghi F, Detsky ME, Farias P, Murray A, Brace D, et al. Measuring diaphragm thickness with ultrasound in mechanically ventilated patients: feasibility, reproducibility and validity. Intensive Care Med. 2015;41:642–9.CrossRefPubMed
31.
Kim WY, Suh HJ, Hong SB, Koh Y, Lim CM. Diaphragm dysfunction assessed by ultrasonography: influence on weaning from mechanical ventilation. Crit Care Med. 2011;39:2627–30.CrossRefPubMed
32.
Matamis D, Soilemezi E, Tsagourias M, Akoumianaki E, Dimassi S, Boroli F, et al. Sonographic evaluation of the diaphragm in critically ill patients. Technique and clinical applications. Intensive Care Med. 2013;39:801–10.CrossRefPubMed
33.
Grosu HB, Lee YI, Lee J, Eden E, Eikermann M, Rose K. Diaphragm muscle thinning in mechanically ventilated patients. Chest. 2012;142:1455–60.CrossRefPubMed
34.
Jung B, Nougaret S, Conseil M, Coisel Y, Futier E, Chanques G, et al. Sepsis is associated with a preferential diaphragmatic atrophy: a critically ill patient study using tridimensional computed tomography. Anesthesiology. 2014;120(5):1182–91.CrossRefPubMed
35.
Sinderby C, Navalesi P, Beck J, Skrobik Y, Comtois N, Friberg S, et al. Neural control of mechanical ventilation in respiratory failure. Nat Med. 1999;5:1433–6.CrossRefPubMed
36.
Liu L, Liu S, Xie J, Yang Y, Slutsky AS, Beck J, et al. Assessment of patient-ventilator breath contribution during neurally adjusted ventilatory assist in patients with acute respiratory failure. Crit Care. 2015;19:43.CrossRefPubMedPubMedCentral
37.
Sinderby C, Liu S, Colombo D, Camarotta G, Slutsky AS, Navalesi P, et al. An automated and standardized neural index to quantify patient-ventilator interaction. Crit Care. 2013;17:R239.CrossRefPubMedPubMedCentral
38.
Sassoon CSH, Zhu E, Caiozzo VJ. Assist-control mechanical ventilation attenuates ventilator-induced diaphragmatic dysfunction. Am J Respir Crit Care Med. 2004;170:626–32.CrossRefPubMed
39.
Papazian L, Forel J-M, Gacouin A, Penot-Ragon C, Perrin G, Loundou A, et al. Neuromuscular blockers in early acute respiratory distress syndrome. N Engl J Med. 2010;363:1107–16.CrossRefPubMed
40.
Hudson MB, Smuder AJ, Nelson WB, Bruells CS, Levine S, Powers SK. Both high level pressure support ventilation and controlled mechanical ventilation induce diaphragm dysfunction and atrophy. Crit Care Med. 2012;40:1254–60.CrossRefPubMedPubMedCentral
41.
Colombo D, Cammarota G, Alemani M, Carenzo L, Barra FL, Vaschetto R, et al. Efficacy of ventilator waveforms observation in detecting patient-ventilator asynchrony. Crit Care Med. 2011;39:2452–7.CrossRefPubMed
42.
Campbell EJ, Gandevia SC, Killian KJ, Mahutte CK, Rigg JR. Changes in the perception of inspiratory resistive loads during partial curarization. J Physiol. 1980;309:93–100.CrossRefPubMedPubMedCentral
43.
Illi SK, Held U, Frank I, Spengler CM. Effect of respiratory muscle training on exercise performance in healthy individuals: a systematic review and meta-analysis. Sports Med. 2012;42:707–24.CrossRefPubMed
44.
Hill K, Jenkins SC, Philippe DL, Cecins N, Shepherd KL, Green DJ, et al. High-intensity inspiratory muscle training in COPD. Eur Respir J. 2006;27:1119–28.CrossRefPubMed
45.
Cader SA, Vale RG, Castro JC, Bacelar SC, Biehl C, Gomes MC, et al. Inspiratory muscle training improves maximal inspiratory pressure and may assist weaning in older intubated patients: a randomised trial. J Physiother. 2010;56:171–7.CrossRefPubMed
46.
Martin AD, Smith BK, Davenport PD, Harman E, Gonzalez-Rothi RJ, Baz M, et al. Inspiratory muscle strength training improves weaning outcome in failure to wean patients: a randomized trial. Crit Care. 2011;15:R84.CrossRefPubMedPubMedCentral
47.
Condessa RL, Brauner JS, Saul AL, Baptista M, Silva AC, Vieira SR. Inspiratory muscle training did not accelerate weaning from mechanical ventilation but did improve tidal volume and maximal respiratory pressures: a randomised trial. J Physiother. 2013;59:101–7.CrossRefPubMed
48.
Elkins M, Dentice R. Inspiratory muscle training facilitates weaning from mechanical ventilation among patients in the intensive care unit: a systematic review. J Physiother. 2015;61:125–34.CrossRefPubMed
49.
Agten A, Maes K, Smuder A, Powers SK, Decramer M, Gayan-Ramirez G. N-Acetylcysteine protects the rat diaphragm from the decreased contractility associated with controlled mechanical ventilation. Crit Care Med. 2011;39:777–82.CrossRefPubMed
50.
Betters JL, Criswell DS, Shanely RA, Van Gammeren D, Falk D, Deruisseau KC, et al. Trolox attenuates mechanical ventilation-induced diaphragmatic dysfunction and proteolysis. Am J Respir Crit Care Med. 2004;170:1179–84.CrossRefPubMed
51.
Supinski GS, Vanags J, Callahan LA. Eicosapentaenoic acid preserves diaphragm force generation following endotoxin administration. Crit Care. 2010;14:R35.CrossRefPubMedPubMedCentral
52.
Travaline JM, Sudarshan S, Roy BG, Cordova F, Leyenson V, Criner GJ. Effect of N-acetylcysteine on human diaphragm strength and fatigability. Am J Respir Crit Care Med. 1997;156:1567–71.CrossRefPubMed
53.
Nathens AB, Neff MJ, Jurkovich GJ, Klotz P, Farver K, Ruzinski JT, et al. Randomized, prospective trial of antioxidant supplementation in critically ill surgical patients. Ann Surg. 2002;236:814–22.CrossRefPubMedPubMedCentral
54.
Heyland D, Muscedere J, Wischmeyer PE, Cook D, Jones G, Albert M, et al. A randomized trial of glutamine and antioxidants in critically ill patients. N Engl J Med. 2013;368:1489–97.CrossRefPubMed
55.
Hermans G, Casaer MP, Clerckx B, Guiza F, Vanhullebusch T, Derde S, et al. Effect of tolerating macronutrient deficit on the development of intensive-care unit acquired weakness: a subanalysis of the EPaNIC trial. Lancet Respir Med. 2013;1:621–9.CrossRefPubMed
56.
Casaer MP, Mesotten D, Hermans G, Wouters PJ, Schetz M, Meyfroidt G, et al. Early versus late parenteral nutrition in critically ill adults. N Engl J Med. 2011;365:506–17.CrossRefPubMed
57.
van Hees HWH, Li Y-P, Ottenheijm CAC, Jin B, Pigmans CJC, Linkels M, et al. Proteasome inhibition improves diaphragm function in congestive heart failure rats. Am J Physiol Lung Cell Mol Physiol. 2008;294:L1260–8.CrossRefPubMedPubMedCentral
58.
Agten A, Maes K, Thomas D, Cielen N, van Hees HWH, Dekhuijzen RPN, et al. Bortezomib partially protects the rat diaphragm from ventilator-induced diaphragm dysfunction. Crit Care Med. 2012;40:2449–55.CrossRefPubMed
59.
Balstad TR, Kaasa S, Solheim TS. Multimodal nutrition/anabolic therapy for wasting conditions. Curr Opin Clin Nutr Metab Care. 2014;17:226–35.CrossRefPubMed
60.
Chikani V, Ho KK. Action of GH on skeletal muscle function: molecular and metabolic mechanisms. J Mol Endocrinol. 2014;52:R107–23.CrossRefPubMed
61.
Takala J, Ruokonen E, Webster NR, Nielsen MS, Zandstra DF, Vundelinckx G, et al. Increased mortality associated with growth hormone treatment in critically ill adults. N Engl J Med. 1999;341:785–92.CrossRefPubMed
62.
Schols AM, Soeters PB, Mostert R, Pluymers RJ, Wouters EF. Physiologic effects of nutritional support and anabolic steroids in patients with chronic obstructive pulmonary disease. A placebo-controlled randomized trial. Am J Respir Crit Care Med. 1995;152:1268–74.CrossRefPubMed
63.
Creutzberg EC, Wouters EF, Mostert R, Pluymers RJ, Schols AM. A role for anabolic steroids in the rehabilitation of patients with COPD? A double-blind, placebo-controlled, randomized trial. Chest. 2003;124:1733–42.CrossRefPubMed
64.
Taylor BE, Buchman TG. Is there a role for growth hormone therapy in refractory critical illness? Curr Opin Crit Care. 2008;14:438–44.CrossRefPubMed
65.
Follath F, Cleland JGF, Just H, Papp JGY, Scholz H, Peuhkurinen K, et al. Efficacy and safety of intravenous levosimendan compared with dobutamine in severe low-output heart failure (the LIDO study): a randomised double-blind trial. Lancet. 2002;360:196–202.CrossRefPubMed
66.
Kass DA, Solaro RJ. Mechanisms and use of calcium-sensitizing agents in the failing heart. Circulation. 2006;113:305–15.CrossRefPubMed
67.
van Hees HWH, Dekhuijzen PNR, Heunks LMA. Levosimendan enhances force generation of diaphragm muscle from patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 2009;179:41–7.CrossRefPubMed
68.
Doorduin J, Sinderby CA, Beck J, Stegeman DF, Van Hees HW, van der Hoeven JG, et al. The calcium sensitizer levosimendan improves human diaphragm function. Am J Respir Crit Care Med. 2012;185:90–5.CrossRefPubMed
69.
Ochala J, Radell PJ, Eriksson LI, Larsson L. EMD 57033 partially reverses ventilator-induced diaphragm muscle fibre calcium desensitisation. Pflugers Arch. 2010;459:475–83.CrossRefPubMed
70.
Schellekens W-JM, van Hees HW, Kox M, Linkels M, Acuña GL, Dekhuijzen PR, et al. Hypercapnia attenuates ventilator-induced diaphragm atrophy and modulates dysfunction. Crit Care. 2014;18:R28.CrossRefPubMedPubMedCentral
71.
Van Hees HW, Schellekens W-JM, Linkels M, Leenders F, Zoll J, Donders R, et al. Plasma from septic shock patients induces loss of muscle protein. Crit Care. 2011;15:R233.CrossRefPubMedPubMedCentral
72.
Reid MB, Lännergren J, Westerblad H. Respiratory and limb muscle weakness induced by tumor necrosis factor-alpha: involvement of muscle myofilaments. Am J Respir Crit Care Med. 2002;166:479–84.CrossRefPubMed
73.
Maes K, Stamiris A, Thomas D, Cielen N, Smuder A, Powers SK, et al. Effects of controlled mechanical ventilation on sepsis-induced diaphragm dysfunction in rats. Crit Care Med. 2014;42:e772–82.CrossRefPubMed
74.
Schellekens W-JM, van Hees HWH, Vaneker M, Linkels M, Dekhuijzen PNR, Scheffer GJ, et al. Toll-like receptor 4 signaling in ventilator-induced diaphragm atrophy. Anesthesiology. 2012;117:329–38.CrossRefPubMed
75.
Okazaki T, Liang F, Li T, Lemaire C, Danialou G, Shoelson SE, et al. Muscle-specific inhibition of the classical nuclear factor-κb pathway is protective against diaphragmatic weakness in murine endotoxemia. Crit Care Med. 2014;42:e501–9.CrossRefPubMed
76.
Divangahi M, Demoule A, Danialou G, Yahiaoui L, Bao W, Xing Z, et al. Impact of IL-10 on diaphragmatic cytokine expression and contractility during Pseudomonas infection. Am J Respir Cell Mol Biol. 2007;36:504–12.CrossRefPubMed
77.
78.
Akira S, Uematsu S, Takeuchi O. Pathogen recognition and innate immunity. Cell. 2006;124:783–801.CrossRefPubMed
79.
Opal SM, Laterre P-F, Francois B, LaRosa SP, Angus DC, Mira J-P, et al. Effect of eritoran, an antagonist of MD2-TLR4, on mortality in patients with severe sepsis: the ACCESS randomized trial. JAMA. 2013;309:1154–62.CrossRefPubMed
80.
Maes K, Testelmans D, Cadot P, Deruisseau K, Powers S, Decramer M, et al. Effects of acute administration of corticosteroids during mechanical ventilation on rat diaphragm. Am J Respir Crit Care Med. 2008;178:1219–26.CrossRefPubMedPubMedCentral
81.
Dekhuijzen PN, Decramer M. Steroid-induced myopathy and its significance to respiratory disease: a known disease rediscovered. Eur Respir J. 1992;5:997–1003.PubMed
82.
Sassoon CSH, Zhu E, Pham HT, Nelson RS, Fang L, Baker MJ, et al. Acute effects of high-dose methylprednisolone on diaphragm muscle function. Muscle Nerve. 2008;38:1161–72.CrossRefPubMed
83.
Maes K, Agten A, Smuder A, Powers SK, Decramer M, Gayan-Ramirez G. Corticosteroid effects on ventilator-induced diaphragm dysfunction in anesthetized rats depend on the dose administered. Respiratory Res. 2010;11:178.CrossRef
84.
De Jonghe B, Sharshar T, Lefaucheur JP, Authier FJ, Durand-Zaleski I, Boussarsar M, et al. Paresis acquired in the intensive care unit: a prospective multicenter study. JAMA. 2002;288:2859–67.CrossRefPubMed
85.
Sprung CL, Annane D, Keh D, Moreno R, Singer M, Freivogel K, et al. Hydrocortisone therapy for patients with septic shock. N Engl J Med. 2008;358:111–24.CrossRefPubMed
86.
Steinberg KP, Hudson LD, Goodman RB, Hough CL, Lanken PN, Hyzy R, et al. Efficacy and safety of corticosteroids for persistent acute respiratory distress syndrome. N Engl J Med. 2006;354:1671–84.CrossRefPubMed
87.
Glickman MH, Ciechanover A. The ubiquitin-proteasome proteolytic pathway: destruction for the sake of construction. Physiol Rev. 2002;82:373–428.CrossRefPubMed
88.
Richardson PG, Barlogie B, Berenson J, Singhal S, Jagannath S, Irwin D, et al. A phase 2 study of bortezomib in relapsed, refractory myeloma. N Engl J Med. 2003;348:2609–17.CrossRefPubMed
89.
Whidden MA, Smuder AJ, Wu M, Hudson MB, Nelson WB, Powers SK. Oxidative stress is required for mechanical ventilation-induced protease activation in the diaphragm. J Appl Physiol. 2010;108:1376–82.CrossRefPubMedPubMedCentral
90.
Smuder AJ, Hudson MB, Nelson WB, Kavazis AN, Powers SK. Nuclear factor-kappaB signaling contributes to mechanical ventilation-induced diaphragm weakness. Crit Care Med. 2012;40:927–34.CrossRefPubMedPubMedCentral
91.
Supinski GS, Wang W, Callahan LA. Caspase and calpain activation both contribute to sepsis-induced diaphragmatic weakness. J Appl Physiol. 2009;107:1389–96.CrossRefPubMedPubMedCentral
92.
Supinski GS, Vanags J, Callahan LA. Effect of proteasome inhibitors on endotoxin-induced diaphragm dysfunction. Am J Physiol Lung Cell Mol Physiol. 2009;296:L994–L1001.CrossRefPubMedPubMedCentral
Metadata
Title
Strategies to optimize respiratory muscle function in ICU patients
Authors
Willem-Jan M. Schellekens
Hieronymus W. H. van Hees
Jonne Doorduin
Lisanne H. Roesthuis
Gert Jan Scheffer
Johannes G. van der Hoeven
Leo M. A. Heunks
Publication date
01-12-2016
Publisher
BioMed Central
Published in
Critical Care / Issue 1/2016
Electronic ISSN: 1364-8535
DOI
https://doi.org/10.1186/s13054-016-1280-y

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