title: Diagnostic strategy in cancer patients with acute respiratory failure.
abstract: OBJECTIVE
  Nearly 15% of cancer patients experience acute respiratory failure (ARF) requiring admission to the intensive care unit, where their mortality is about 50%. This review focuses on ARF in cancer patients. The most recent literature is reviewed, and emphasis is placed on current controversies, most notably the risk/benefit ratio of fiberoptic bronchoscopy and BAL in patients with severe hypoxemia.
  
  
  BACKGROUND
  Fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) is the cornerstone of the causal diagnosis. However, the low diagnostic yield of about 50%, related to the widespread use of broad-spectrum antimicrobial therapy in cancer patients, has generated interest in high-resolution computed tomography (HRCT) and primary surgical lung biopsy. In patients with hypoxemia, bronchoscopy and BAL may trigger a need for invasive mechanical ventilation, thus considerably decreasing the chances of survival.
  
  
  CONCLUSIONS
  The place for recently developed, effective, noninvasive diagnostic tools (tests on sputum, blood, urine, and nasopharyngeal aspirates) needs to be determined. The prognosis is not markedly influenced by cancer characteristics; it is determined chiefly by the cause of ARF, need for mechanical ventilation, and presence of other organ failures. Although noninvasive ventilation reduces the need for endotracheal intubation and diminishes mortality rate, its prolonged use in patients with severe disease may preclude optimal diagnostic and therapeutic management. The appropriateness of switching to endotracheal mechanical ventilation in patients who fail noninvasive ventilation warrants evaluation.
  
  
  CONCLUSIONS
  This review discusses risks and benefits from invasive and non invasive diagnostic and therapeutic strategies in critically ill cancer patients with acute respiratory failure. Avenues for research are also suggested in order to improve survival in these very high risk patients.
authors.affiliation: Service de Réanimation Médicale, Hôpital Saint-Louis et Université Paris 7, Paris, France. elie.azoulay@sls.ap-hop-paris.fr
authors.forename: Elie
authors.initials: E
authors.lastname: Azoulay
authors.forename: Benoît
authors.initials: B
authors.lastname: Schlemmer
mesh_terms: D003422:Critical Care; D003937:Diagnosis, Differential; D005602:France; D006801:Humans; D009369:Neoplasms; D012128:Respiratory Distress Syndrome