Pulmonary Diagnostic Procedures in the Critically Ill

Electromagnetic navigation bronchoscopy-guided fine needle aspiration for the diagnosis of lung lesions

Many peripheral lung lesions are beyond the reach of conventional bronchoscopes, and require percutaneous CT-guided or open surgical biopsy, which carry increased risks to the patient. Electromagnetic navigation bronchoscopy (ENB) is a relatively new technique, which uses an image guided localization system to direct steerable bronchoscopic tools to predetermined points within the bronchial tree. This technology allows improved access to peripheral lesions in particular. We investigated the sensitivity and specificity of ENB-guided fine needle aspiration (FNA) in the diagnosis of lung lesions. All ENB-guided FNAs performed at one institution were included in the study. The superDimension i-Logic System™ was used in all cases. Pathologic reports of the ENB-guided FNAs, as well as all other pulmonary sampling performed simultaneously with the FNA and within 1 year of the ENB-guided FNA were reviewed. Patients with a positive ENB-guided FNA or malignancy within the same lobe within the follow-up period were considered positive for malignancy. Patients with an atypical diagnosis but no definitive malignancy were considered negative for malignancy for statistical purposes. Ninety-one patients underwent 95 ENB-guided FNAs over a 3-year period. Thirty-five patients (38%) were positive for malignancy. ENB-guided FNA had a sensitivity of 63% for the detection of malignancy. The sensitivity for the detection of malignancy using all ENB-guided sampling methods, including FNA, bronchoscopic biopsy, and bronchial brushing was 83%. Pathologists and cytotechnologists should be aware of ENB-guided FNA as an emerging technology with a relatively high sensitivity for the diagnosis of peripheral lung lesions.

Indications and Efficacy of Fiberoptic Bronchoscopy in the ICU: Have They Changed Since Its Introduction in Clinical Practice?

Purpose. We describe characteristics, utility, and safety of fiberoptic bronchoscopy (FOB) in an intensive care unit (ICU). Methods. Prospective and descriptive cohort of patients admitted to a respiratory ICU from March 2010 to June 2012. Results. A total of 102 FOBs were performed in 84 patients among 580 patients that were admitted to the ICU. Mean age was 48±17 years. FOB was useful in 65% of diagnostic procedures and 83% of therapeutic procedures, with an overall utility of 75%. Indications and utility according to indication were pneumonia in 31 cases, utility of 52%; percutaneous tracheostomy guidance in 26 cases, utility of 100%; atelectasis in 25 cases, utility of 76%; airway exploration in 16 cases, utility of 75%; hemoptysis in two cases, utility of 100%; and difficult airway intubation in two cases, utility of 100%. A decrease in oxygen saturation (SpO2) of >5% during FOB was present in 65% of cases, and other minor complications were present in 3.9% of cases. Conclusions. Reasons for performing FOB in the ICU have remained relatively stable over time with the exception of the addition of percutaneous tracheostomy guidance. Our series documents current indications and also the utility and safety of this procedure.

Effect of Bronchoalveolar Lavage on Gas Exchange in Patients with Diffuse Lung Disease and Respiratory Failure

The effect of fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) on arterial oxygenation was examined in 22 patients with acute respiratory failure requiring mechanical ventilatory support. Arterial blood gases were determined immediately prior to BAL and at 15, 60, 120, and 360 minutes following BAL. PaO2/FIO2 decreased at 15 minutes and continued to decrease to approximately 33% below the baseline value at 2 hours. PaO2/FIO2 then remained constant over the remainder of the 6-hour study period. No substantial changes in FIO2, level of positive end-expiratory pressure, or intravenous pressor requirements occurred during the period of observation. Patients with lower pre-BAL PaO2/FIO2 ratios showed the least reduction in PaO2/FiO2 following BAL The BAL was diagnostic in 9 of 22 (41%) patients ( Pneumocystis carinii pneumonia in 5, bacterial pneumonitis in 2, and neoplastic involvement of the lung in 2). BAL was associated with mild deterioration of gas exchange but did not require significant changes in ventilatory or hemodynamic support for the 6-hour interval studied.

Bronchoscopy in the intensive care unit

The development of the flexible, fiberoptic bronchoscope has made bronchoscopic examinations possible in ICU patients undergoing mechanical ventilation. Over the years, the number of such procedures has greatly increased, with both diagnostic and therapeutic objectives, such as performing difficult intubation, management of atelectasis and hemoptysis, diagnosis of nosocomial pneumonia in ventilated patients, and early detection of airway lesions in selected situations, such as high-frequency ventilation. The complication rate can be kept low if the endoscopist has a precise knowledge of the many pathophysiological and technical facets particular to bronchoscopy under these difficult conditions. This article reviews some of these aspects, in the light of our personal experience.

Bronchoscopy in the critical-care unit

To determine the diagnostic and therapeutic usefulness as well as safety of flexible fiberoptic bronchoscopy (FFB) in patients admitted to the critical-care unit (CCU), we conducted a review of all such procedures done in our CCU from 1985 to 1988. A total of 129 patients underwent 198 FFB, of which 76% were in mechanically ventilated patients. FFB was done for diagnostic purposes in 87, for therapeutic purposes in 93, and for both reasons in 18. Of the 71 diagnostic FFB performed for cultures, 27 (38%) were positive but only 18 (25%) influenced patient management. An additional 25 FFB were helpful in making therapeutic decisions even though the cultures were negative. Ten of 13 FFB performed for evaluation of airways and 1 of 3 done for hemoptysis were helpful. Of the 90 FFB done because of retained secretions, 37 (41%) showed mucous plugs or significant secretions, but clinical improvement was noted in only 17 (19%). Overall, FFB contributed substantially to patient management in 82 of the 198 procedures (41%). Seven patients had transient complications, but no deaths occurred. We conclude that FFB is safe and can be helpful in the CCU setting.