endosonographic procedures , including endobronchial ultrasound ( ebus)-guided transbronchial needle aspiration ( tbna ) and endoscopic ultrasound ( eus)-guided fine - needle aspiration ( fna ) are routinely used for accessing mediastinal and hilar lymph nodes and masses . in patients with hypoxemia , excessive cough , raised intracranial tension , or with central airway obstruction due to lesions compressing the trachea ; eus - fna may be safer than ebus - tbna as it employs the esophageal route . however , patients with central airway obstruction requiring mechanical ventilation are often managed in respiratory care units , where eus - fna may not be available . in this situation , the pulmonologist can use the ebus scope for performing a technique known as eus ( with an echobronchoscope)-guided fna ( eus - b - fna ) . this procedure has been reported to have a good diagnostic performance in the evaluation of mediastinal lesions . herein , we describe a patient with respiratory failure due to airway obstruction by a mediastinal tumor , who was being mechanically ventilated . a 50-year - old man presented to the emergency department with stridor of 1-week duration . there was a significant reduction in appetite and he had lost 5 kg of his body weight . on admission to our facility , physical examination revealed an afebrile patient with a heart rate of 120 beats / min , respiratory rate of 38 breaths / min , and blood pressure of 80/50 mmhg . contrast - enhanced computed tomography ( ct ) of his chest revealed the presence of a mass in the subcarinal region encasing the lower trachea and main bronchi and consolidation in the right upper lobe [ figure 1 ] . mass in the subcarinal region encasing both the main bronchi and causing compression of the pulmonary vessels the patient was intubated with an endotracheal tube ( 7.0 mm internal diameter ) and mechanically ventilated . he was initiated on intravenous co - amoxiclav ( 1.2 g thrice a day ) . however , the patient could not be weaned off the ventilator over the next 5 days . on the 6 day , eus - b - fna of the subcarinal mass was performed . cytological examination showed loosely cohesive clusters and dispersed population of small - sized tumor cells with hyperchromatic nuclei showing focal nuclear molding suggestive of small cell carcinoma of the lung [ figure 2 ] . photomicrograph of the aspirate from the mediastinal mass obtained by endoscopic ultrasound ( with an echobronchoscope)-guided fine - needle aspiration showing loosely cohesive clusters and dispersed population of small - sized tumor cells with hyperchromatic nuclei showing focal nuclear molding suggestive of small cell carcinoma . background shows nuclear debris ( h and e , 40 ) the final clinicoradiological stage was iiib ( t4 n3 m0 ) , but the patient had a poor performance status ( eastern cooperative oncology group score of 4 ) . placement of a metallic tracheobronchial y - stent was considered but was not performed as the patient 's legal representative refused consent . chemotherapy with cisplatin 100 mg ( 85% of 60 mg / m of body surface area [ bsa ] ) and irinotecan 160 mg ( 90% of 100 mg / m of bsa ) were administered . after a week , the patient was successfully weaned off the ventilator and was discharged to home care . however , the disease progressed and the patient succumbed to his illness 3 months after the diagnosis . the index case illustrates the utility of eus - b - fna in accessing mediastinal lesions in mechanically ventilated patients , where ebus - tbna may be technically difficult or not feasible . a diagnosis of advanced lung cancer was made and the administration of palliative chemotherapy enabled liberation from mechanical ventilation . mediastinal or hilar lesions in critically ill patients can be approached endoscopically by the pulmonologist through the airway using tbna that can be performed with or without ebus guidance . both conventional and ebus - guided tbna have been described in patients with respiratory failure , who are mechanically ventilated through an endotracheal tube ; however , they are not performed frequently . this is because a small - sized endotracheal tube does not allow the entry of the echobronchoscope ( insertion tube diameter , 6.9 mm ) . further , as the procedure requires a few minutes , significant hypoxia may occur in patients with a poor respiratory reserve . the index patient was being ventilated with a small - sized endotracheal tube ( internal diameter of 7.0 mm ) and he had significant hypoxemia . eus may be useful in such patients as the access is through the esophagus , thus not compromising ventilation . eus offers access to lymph node stations 5 ( para - aortic ) , 8 ( paraesophageal ) , and 9 ( pulmonary ligament ) in addition to stations 4 l ( left lower paratracheal ) and 7 ( subcarinal ) . however , this procedure is usually performed by gastroenterologists and many respiratory intensive care units may not have easy access to this technology , especially at the bedside . eus - b - fna , which is performed by the pulmonologist with the same echobronchoscope used to perform ebus - tbna overcomes this limitation . moreover , the introduction of the ebus scope ( 6.9 mm in diameter ) may be easier than the introduction of the eus scope ( 1214 mm in diameter ) in patients who also have esophageal narrowing . due to these reasons , ct - guided fna was not employed as it would have entailed a high risk of pneumothorax due to the central location of the mass . a systematic review of the pubmed database using the search string : ( ebus or  endobronchial ultrasound  or transbronchial needle aspiration  ) and ( icu or  intensive care unit  or  critically ill  or mechanical ventilation *  or  mechanically ventilated  or intubated or  endotracheal tube  ) yielded 10 reports ( 62 patients ) of endoscopic interventions ( conventional tbna , ebus - tbna , eus - fna , or eus - b - fna ) for mediastinal / hilar lesions in critically ill patients [ table 1 ] . forty - six patients could be diagnosed successfully resulting in an overall yield of 74.2% ; there were no major complications . moreover , the diagnostic information obtained from the procedure led to a change in the treatment decision in most of these patients ( 49/62 ; 79% ) . in our case , eus - b - fna allowed institution of appropriate chemotherapy and facilitated liberation of our patient with advanced lung cancer from mechanical ventilation , an event not commonly encountered in clinical practice . published reports of endoscopic diagnostic interventions for accessing mediastinal / hilar lesions in critically ill patients the index case demonstrates that eus - b - fna is a valuable addition to the armamentarium of the pulmonologist for diagnosing mediastinal lesions in critically ill patients , including situations such as respiratory failure , which preclude a diagnostic bronchoscopy and ebus - tbna .