Profitability of high risk bronchoscopes with non-invasive ventilatory support

Introduction: Respiratory complications are very frequent in immunosuppressed patients, being one of its main causes of morbimortality. For the diagnosis, it is very useful to take samples by Fiberoptic bronchoscopy (FB), but in many cases the severe respiratory compromise implies a very high vital risk. Some studies in this area have been carried out although they are still low.

Material and methods: Descriptive and observational study of 20 immunocompromised patients with severe respiratory compromise. It was performed a FB in the presence of opportunistic infection. The ventilatory support was made with the Philips Respironic V60 Ventilator. Clinical, radiological and ventilatory data, complications and results were collected.

Results: Of the 20 patients (13 women). Mean age 57 years. 6 cases had a solid neoplasm, 5 hematologic (4 hematopoietic transplant), 3 solid organ transplant, 2 HIV and 4 other immunosuppression. Radiologically 18 had diffuse pulmonary infiltrates. The estimated mean PaFi (PaO₂/FiO₂) was 137 (77 – 238), in 2 cases there was hypercapnia. Before beginning the bronchoscopy, the respiratory situation was optimized with non invasive mechanical ventilation (NIMV): IPAP 16 cmH₂O (10 – 22), EPAP 8 cmH₂O (5 – 10), mean FiO₂ 0.62 (0.5 to 1), and mean SatO₂ 95% (94 – 99). Sedation was performed with intravenous midazolam (2 – 4 mg) and in one case, in addition, fentanyl. BAS and BAL samples were taken in all cases, and occasionally brushing and bronchial biopsy. The ventilatory parameters were modified during the procedure to maintain an adequate tidal volume and oxygen saturation. Gasometry after the FB was pH 7.38 (7.28 – 7.45), pCO₂ 42 (28 – 62), HCO₃ 24 (19 – 29).

In 17 cases there were no complications; 1 patient suffered a pneumothorax; 2 had severe deterioration, one immediately, another 48 hours later, both needed admission in the Intensive Unit Care.

Microbiologically, the overall profitability was 80% (16 positive results): 1 Acinetobacter, 2 Aspergillus, 4 Cytomegalovirus, 3 P. jirovecii, 4 CMV + PCP, 1 Aspergillus + CMV, 1 alveolar hemorrhage.

Conclusions: The NIMV is useful to be able to carry out a diagnostic fiberbronchoscopy in very high risk patients quite safely, which together with its high profitability make the combination of both techniques an option to take into account in this type of patients.