Email updates

Keep up to date with the latest news and content from Critical Care and BioMed Central.

Highly Accessed Commentary

Non-invasive mechanical ventilation in hematology patients: let's agree on several things first

David Schnell12, Virginie Lemiale12 and Élie Azoulay12*

Author Affiliations

1 Assistance Publique - Hôpitaux de Paris, Hôpital Saint-Louis, Réanimation médicale, 1 avenue Claude Vellefaux, 75010 Paris, France

2 University Paris-7 Paris-Diderot, UFR de Médecine, 75010 Paris, France

For all author emails, please log on.

Critical Care 2012, 16:175  doi:10.1186/cc11830


See related research by Molina et al., http://ccforum.com/content/16/4/R133


The electronic version of this article is the complete one and can be found online at: http://ccforum.com/content/16/6/175


Published:19 November 2012

© 2012 BioMed Central Ltd.

Abstract

Acute respiratory failure is a dreaded and life-threatening event that represents the main reason for ICU admission. Respiratory events occur in up to 50% of hematology patients, including one-half of those admitted to the ICU. Mortality from acute respiratory failure in hematology patients depends on the patient's general status, acute respiratory failure etiology, need for mechanical ventilation and associated organ dysfunction. Non-invasive mechanical ventilation is clearly beneficial for chronic obstructive pulmonary disease exacerbation and cardiogenic pulmonary edema. These benefits are based mainly on the avoidance of invasive mechanical ventilation complications. Non-invasive mechanical has also been recommended in hematology patients with acute respiratory failure but its real benefits remain unclear in these settings. There is growing concern about the safety of non-invasive mechanical ventilation to treat hypoxemic acute respiratory failure overall, but also in hematology patients. Prophylactic non-invasive mechanical ventilation in patients with acute respiratory failure but not respiratory distress seems to be effective in hematology patients with a reduced rate of intubation. However, curative non-invasive mechanical ventilation should be restricted to those patients with isolated respiratory failure, with fast improvement of respiratory distress under non-invasive mechanical ventilation, and with rapid switch to intubation to avoid deleterious delays in optimal invasive mechanical ventilation.

Commentary

In a previous issue of Critical Care, Molina and colleagues provide the results of a large multicenter Spanish observational cohort study of hematology patients with acute respiratory failure (ARF) [1]. Their main findings are that non-invasive mechanical ventilation (NIV) failure is an independent risk factor for ICU mortality. Indeed, NIV patients exhibited higher mortality rates compared with patients who were intubated early. Not surprisingly, cardiogenic pulmonary edema was associated with reduced proportion of NIV failure.

The observational design does not actually allow any firm conclusion about NIV efficacy in hematology patients. The poorer prognosis associated with NIV failure could simply result from patient selection, clinicians being less keen to intubate patients without lifespan-expanding therapy or those who were older or sickest. Late intubation would thus only be a surrogate marker of poor prognosis. Nevertheless, this study is along the line of other studies in the literature that show early intubation to be associated with lower mortality [2,3]. In hematology patients with hypoxemic ARF, therefore, the questionable benefit from NIV supports the dilemma of intubation timing faced by clinicians managing these patients.

ARF occurs in up to 50% of hematology patients and is the leading reason for ICU admission in this population. Despite significant improvement in the last years [4,5], ARF still carries a high mortality rate of 50% overall, with even higher rates in patients needing mechanical ventilation [4,6,7]. The high incidence of cancer together with the use of a highly intensive curative regimen will increase the number of patients at risk of respiratory complications, and physicians will be asked to manage these patients more and more.

NIV is now recognized as the first-line therapy for patients with ARF due to chronic obstructive pulmonary disease exacerbation or cardiogenic pulmonary edema [8]. The clear benefit of NIV in these patients relies on the reduced rate of complications from invasive mechanical ventilation. NIV has also been recommended for hypoxemic ARF in immunocompromised patients [9]. In the subgroup of hematology patients, invasive mechanical ventilation has been associated with the worse prognosis of ARF [4,6,7] and NIV may therefore be particularly beneficial to these patients. However, published studies have inconsistently found a benefit from NIV in these patients [1,4,6,10-12].

Several factors may explain these discordant results. First, studies did not control the timing of NIV implementation and evaluated together prophylactic NIV (in patients with hypoxemia but no respiratory distress) and curative NIV (in patients with established respiratory distress) [10,13]. Second, the unit where NIV was performed - the hematology ward or the ICU - differed between studies [11,12]. Early ICU admission and the opportunity for tight monitoring probably positively impacted the results, whereas delayed ICU admission for patients treated in the hematology ward may have worsened prognosis with delayed intubation and treatment of associated organ failures [13]. Third, studies included patients with ARF from various etiologies, some of which may better respond to NIV. Finally, studies did not take into account associated organ dysfunctions that may have hampered NIV efficacy.

The overall lack of actually proven benefit from NIV in hypoxemic ARF of hematology patients therefore raises safety concerns for its use in patients who may benefit from early intubation and mechanical ventilation [14]. The recent advances in life-sustaining therapies and the better outcome of hematology patients admitted to the ICU in the last years strengthen these concerns [4,5].

Taken together, studies evaluating NIV in hematology patients highlight the deleterious effects of NIV failure and late intubation, as does the study by Molina and colleagues [1,10,13]. Improving NIV results in these patients will probably derive from tailor-made management based on the lessons we have learned from these studies (Figure 1 and Table 1). In our belief, this relies on the three following points: improved patient selection, careful identification of ARF etiology [7], and early assessment of NIV efficacy. Available evidence supports the use of prophylactic NIV performed in the ICU in hematology patients [10]. These benefits may result from improved oxygenation and reduced work of breathing that alleviate respiratory load. Prophylactic NIV may also help to secure diagnostic procedures such as fiberoptic bronchoscopy and bronchoalveolar lavage [15]. In opposition, we believe the reason why NIV may be effective for hypoxemic ARF in hematology patients and not in other settings is highly questionable. We therefore recommend the cautious use of curative NIV only in patients with isolated ARF and with an early assessment of its efficacy. Curative NIV should be discouraged in patients with an associated extra-respiratory organ failure and should be contraindicated in those with two or more extra-respiratory failures.

thumbnailFigure 1. Propositions for the use of non-invasive mechanical ventilation in hematology patients with acute respiratory failure. ARF, acute respiratory failure; NIV, non-invasive mechanical ventilation; RRT, renal replacement therapy.

Table 1. Situations in which NIV should be encouraged or avoided in hematology patients

Ultimately, clinicians must be aware that the identification of a rapidly reversible etiology of ARF probably constitutes the key factor for the success of curative NIV. When no rapid improvement is obtained, invasive mechanical ventilation must be considered early to ensure the highest chance of survival for hematology patients with hypoxemic ARF [13].

Abbreviations

ARF: acute respiratory failure; NIV: non-invasive mechanical ventilation.

Competing interests

The authors declare that they have no competing interests.

Authors' contributions

All authors contributed equally to the manuscript.

Acknowledgements

This study was supported by a grant from the Assistance-Publique Hôpitaux de Paris (AOM 04139) and by the French Society for Intensive Care Medicine.

References

  1. Molina R, Bernal T, Borges M, Zaragoza R, Bonastre J, Granada RM, Rodriguez-Borregan JC, Nunez K, Seijas I, Ayestaran I, Albaiceta GM, EMEHU Study Investigators: Ventilatory support in critically ill hematology patients with respiratory failure.

    Crit Care 2012, 16:R133. PubMed Abstract | BioMed Central Full Text OpenURL

  2. Depuydt PO, Benoit DD, Vandewoude KH, Decruyenaere JM, Colardyn FA: Outcome in non-invasively and invasively ventilated hematologic patients with acute respiratory failure.

    Chest 2004, 126:1299-1306. PubMed Abstract | Publisher Full Text OpenURL

  3. Groeger JS, White P, Nierman DM, Glassman J, Shi W, Horak D, Price K: Outcome for cancer patients requiring mechanical ventilation.

    J Clin Oncol 1999, 17:991-997. PubMed Abstract | Publisher Full Text OpenURL

  4. Azoulay E, Alberti C, Bornstain C, Leleu G, Moreau D, Recher C, Chevret S, Le Gall JR, Brochard L, Schlemmer B: Improved survival in cancer patients requiring mechanical ventilatory support: impact of non-invasive mechanical ventilatory support.

    Crit Care Med 2001, 29:519-525. PubMed Abstract | Publisher Full Text OpenURL

  5. Khassawneh BY, White P, Anaissie EJ, Barlogie B, Hiller FC: Outcome from mechanical ventilation after autologous peripheral blood stem cell transplantation.

    Chest 2002, 121:185-188. PubMed Abstract | Publisher Full Text OpenURL

  6. Azoulay E, Thiery G, Chevret S, Moreau D, Darmon M, Bergeron A, Yang K, Meignin V, Ciroldi M, Le Gall JR, Tazi A, Schlemmer B: The prognosis of acute respiratory failure in critically ill cancer patients.

    Medicine (Baltimore) 2004, 83:360-370. PubMed Abstract | Publisher Full Text OpenURL

  7. Azoulay E, Mokart D, Lambert J, Lemiale V, Rabbat A, Kouatchet A, Vincent F, Gruson D, Bruneel F, Epinette-Branche G, Lafabrie A, Hamidfar-Roy R, Cracco C, Renard B, Tonnelier JM, Blot F, Chevret S, Schlemmer B: Diagnostic strategy for hematology and oncology patients with acute respiratory failure: randomized controlled trial.

    Am J Respir Crit Care Med 2010, 182:1038-1046. PubMed Abstract | Publisher Full Text OpenURL

  8. Brochard L: Non-invasive ventilation for acute respiratory failure.

    JAMA 2002, 288:932-935. PubMed Abstract | Publisher Full Text OpenURL

  9. Antonelli M, Conti G, Rocco M, Bufi M, De Blasi RA, Vivino G, Gasparetto A, Meduri GU: A comparison of non-invasive positive-pressure ventilation and conventional mechanical ventilation in patients with acute respiratory failure.

    N Engl J Med 1998, 339:429-435. PubMed Abstract | Publisher Full Text OpenURL

  10. Azoulay E, Lemiale V: Non-invasive mechanical ventilation in hematology patients with hypoxemic acute respiratory failure: a false belief?

    Bone Marrow Transplant 2012, 47:469-472. PubMed Abstract | Publisher Full Text OpenURL

  11. Hilbert G, Gruson D, Vargas F, Valentino R, Gbikpi-Benissan G, Dupon M, Reiffers J, Cardinaud JP: Non-invasive ventilation in immunosuppressed patients with pulmonary infiltrates, fever, and acute respiratory failure.

    N Engl J Med 2001, 344:481-487. PubMed Abstract | Publisher Full Text OpenURL

  12. Wermke M, Schiemanck S, Hoffken G, Ehninger G, Bornhauser M, Illmer T: Respiratory failure in patients undergoing allogeneic hematopoietic SCT - a randomized trial on early non-invasive ventilation based on standard care hematology wards.

    Bone Marrow Transplant 2012, 47:574-580. PubMed Abstract | Publisher Full Text OpenURL

  13. Adda M, Coquet I, Darmon M, Thiery G, Schlemmer B, Azoulay E: Predictors of non-invasive ventilation failure in patients with hematologic malignancy and acute respiratory failure.

    Crit Care Med 2008, 36:2766-2772. PubMed Abstract | Publisher Full Text OpenURL

  14. Truwit JD, Bernard GR: Non-invasive ventilation - don't push too hard.

    N Engl J Med 2004, 350:2512-2515. PubMed Abstract | Publisher Full Text OpenURL

  15. Gruson D, Hilbert G, Valentino R, Vargas F, Chene G, Bebear C, Allery A, Pigneux A, Gbikpi-Benissan G, Cardinaud JP: Utility of fiberoptic bronchoscopy in neutropenic patients admitted to the intensive care unit with pulmonary infiltrates.

    Crit Care Med 2000, 28:2224-2230. PubMed Abstract | Publisher Full Text OpenURL