Adult and paediatric size bronchoscopes for bronchoalveolar lavage in mechanically ventilated patients: yield and side effects

An evolving role for endobronchial ultrasonography in the intensive care unit

Endobronchial ultrasound (EBUS) bronchoscopy is an established minimally-invasive modality for visualization, characterization, and guidance of sampling of paratracheal and parabronchial structures and tissues. In the intensive care unit (ICU), rapidly obtaining an accurate diagnosis is paramount to the management of critically ill patients. In some instances, diagnosing and confirming terminal illness in a critically ill patient provides needed closure for patients and their loved ones. Currently available data on feasibility, safety, and yield of EBUS bronchoscopy in critically ill patients is based on single center experiences. These data suggest that in select ICU patients convex and radial probe-EBUS bronchoscopy can serve as useful tools in the evaluation of mediastinal lymphadenopathy, central airway obstruction, pulmonary embolism, and peripheral lung lesions. Barriers to the use of EBUS bronchoscopy in the ICU include: (I) requirement for dedicated equipment, prolonged procedure time, and bronchoscopy team expertise that may not be available; (II) applicability to a limited number of patients and conditions in the ICU; and (III) technical difficulty related to the relatively large outer diameter of the convex probe-EBUS bronchoscope and an increased risk for adverse cardiopulmonary consequences due to intermittent obstruction of the artificial airway. While the prospects for EBUS bronchoscopy in critically ill patients appear promising, judicious patient selection in combination with bronchoscopy team expertise are of utmost importance when considering performance of EBUS bronchoscopy in the ICU setting.

Wall-mounted Versus Handheld Syringe Suction for Pediatric Bronchoalveolar Lavage: A Randomized Controlled Trial

BACKGROUND

Bronchoalveolar lavage (BAL) via flexible bronchoscopy is a valuable diagnostic technique in children. The quality of BAL is directly related to the volume of the fluid recovered. Continuous wall suctioning and handheld syringe suctioning are the 2 commonly used methods, but they are rarely compared in children. We aimed to compare the above 2 suctioning techniques for BAL in the pediatric age group.

METHODS

This randomized controlled study enrolled children from 1 month to 18 years of age undergoing flexible bronchoscopy and BAL. We compared continuous wall suctioning and the handheld syringe suctioning technique. The primary outcome was the percentage of BAL fluid recovery in 2 different suctioning techniques. Secondary outcomes included technical acceptable BAL and yield of various diagnostic tests in BAL.

RESULTS

The study included 73 children (48 boys) with a median (interquartile range) age of 30 (8, 108) months. There were 37 children in the wall mount group and 36 children in the syringe suction group. Baseline characteristics of the groups were similar. The wall mount suction had more recovery of BAL fluid compared with the syringe method (43.6±8.4% vs. 37.8±8.5%, P=0.004). The proportion of BAL having a fluid recovery of ≥40% was also high in the wall mount suction [31 (83.8%) vs. 17 (47.2%); P=0.001]. There was no difference in diagnostic yield between the groups.

CONCLUSION

Wall mount suction had better BAL fluid recovery compared with handheld syringe suction in children undergoing flexible bronchoscopy. The diagnostic yield was similar in both groups.

Guidelines for diagnostic flexible bronchoscopy in adults: Joint Indian Chest Society/National College of chest physicians (I)/Indian association for bronchology recommendations

Flexible bronchoscopy (FB) is commonly performed by respiratory physicians for diagnostic as well as therapeutic purposes. However, bronchoscopy practices vary widely across India and worldwide. The three major respiratory organizations of the country supported a national-level expert group that formulated a comprehensive guideline document for FB based on a detailed appraisal of available evidence. These guidelines are an attempt to provide the bronchoscopist with the most scientifically sound as well as practical approach of bronchoscopy. It involved framing appropriate questions, review and critical appraisal of the relevant literature and reaching a recommendation by the expert groups. The guidelines cover major areas in basic bronchoscopy including (but not limited to), indications for procedure, patient preparation, various sampling procedures, bronchoscopy in the ICU setting, equipment care, and training issues. The target audience is respiratory physicians working in India and well as other parts of the world. It is hoped that this document would serve as a complete reference guide for all pulmonary physicians performing or desiring to learn the technique of flexible bronchoscopy.

The use of bronchoscopy in critically ill patients: considerations and complications

INTRODUCTION

Flexible bronchoscopy has been well established for diagnostic and therapeutic purposes in critically ill patients. Areas covered: This review outlines the clinical evidence of the utility and safety of flexible bronchoscopy in the intensive care unit, as well as specific considerations, including practical points and potential complications, in critically ill patients. Expert commentary: Its ease to learn and perform and its capacity for bedside application with relatively few complications make flexible bronchoscopy an indispensable tool in the intensive care unit setting. The main indications for flexible bronchoscopy in the intensive care unit are the visualization of the airways, sampling for diagnostic purposes and management of the artificial airways. The decision to perform flexible bronchoscopy can only be made by trade-offs between potential risks and benefits because of the fragile nature of the critically ill. Flexible bronchoscopy-associated serious adverse events are inevitable in cases of a lack of expertise or appropriate precautions.

Continuous ventilation during intubation through a supraglottic airway device guided by fiberoptic bronchoscopy: a observational assessment

INTRODUCTION

supraglottic airway devices remain, despite advances in video laryngoscopy, important tools in the management of unexpected difficult airways. Intubation through a functioning supraglottic airway device with the aid of a fiberoptic bronchoscope is a well-known technique usually performed in apnoea. With a simple modification, the patient can be ventilated during this procedure.

METHODS

In this observational study, Tracheal intubation Assisted by Bronchoscopy And Sad during Continuous Oxygenation (TABASCO) was performed as part of department training routine in 26 elective, fasted patients. A supraglottic airway device was used as a conduit for an endotracheal tube.

RESULTS

All patients were easily intubated and ventilation was maintained during the procedure. The gap between the outer diameter of the fiberoptic bronchoscope and the inner diameter of the endotracheal tube was more than 2 mm in 25 of 26 patients. Effective ventilation was confirmed by clinical signs, capnography and pressure-volume curves. No signs of airtrapping occurred.

DISCUSSION

No adverse events were observed during this form of airway management in this small series of elective and fasted patient when performed by an anaesthesiologist experienced in fiberoptic intubation. A gap between fiberoptic bronchoscope and endotracheal tube inner lumen seems to be prerequisite for easy ventilation through the supraglottic airway. In trained hands, this technique can be a means to secure an airway with an intubating bronchoscope without pausing ventilations. A prerequisite for this is a well-functioning supraglottic airway device.

Percutaneous dilatational tracheostomy with a double-lumen endotracheal tube: a comparison of feasibility, gas exchange, and airway pressures

OBJECTIVE

Gas exchange and airway pressures are markedly altered during percutaneous dilatational tracheostomy (PDT). A double-lumen endotracheal tube (DLET) has been developed for better airway management during PDT. The current study prospectively evaluated the in vivo feasibility, gas exchange, and airway pressures during PDT with DLET compared with a conventional endotracheal tube (ETT).

METHODS

According to eligibility criteria, patients were divided into a case group (those receiving PDT with DLET) and a control group (those receiving PDT with a conventional ETT). The Ciaglia single-dilator technique was used for PDT in both groups. The primary end point of this study was the feasibility of tracheostomy with DLET. The secondary end points were a comparison of gas exchange, airway pressures, minute volume, and tidal volume before, during, and after PDT performed with DLET and conventional ETT.

RESULTS

Ten patients meeting the inclusion criteria were assigned to each group. PDTs were performed without difficulties in nine patients in the DLET group and 10 patients in the conventional ETT group. During PDT, gas exchange, airway pressures, and minute ventilation remained more stable in the DLET group and were significantly different from those in the conventional ETT group.

CONCLUSIONS

PDT with DLET can be performed safely without difficulties limiting the technique. Furthermore, during PDT, the use of the DLET resulted in more stable gas exchange, airway pressures, and ventilation than PDT with a conventional ETT.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01691222; URL: www.clinicaltrials.gov.

Tumor necrosis factor-alpha and angiostatin are mediators of endothelial cytotoxicity in bronchoalveolar lavages of patients with acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is characterized by an extensive alveolar capillary leak, permitting contact between intra-alveolar factors and the endothelium. To investigate whether factors contained in the alveolar milieu induce cell death in human lung microvascular endothelial cells, we exposed these cells in vitro to bronchoalveolar lavage fluid (BALF) supernatants from control patients, patients at risk of developing ARDS, and patients with early- and late-phase ARDS. In contrast to BALF from control patients, a significant cytotoxicity was found in BALF from patients at risk of developing ARDS, with late-phase ARDS, and especially from patients with early-phase ARDS. Subsequently, we determined the levels of factors known to exert cytotoxicity in endothelial cells, i.e., tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, and angiostatin. BALF from patients at risk of developing ARDS, with early-phase ARDS, and with late-phase ARDS, contained increased levels of TNF-alpha and angiostatin, but not of TGF-beta1, as compared with BALF from control patients. Whereas inhibition of TGF-beta1 had no effect in this setting, neutralization of TNF-alpha or angiostatin inhibited the cytotoxic activity on endothelial cells of part of the early-phase ARDS BALF. These results indicate that TNF-alpha and angiostatin may contribute to ARDS-related endothelial injury.

Effects of fiberoptic bronchoscopy during mechanical ventilation in a lung model

STUDY OBJECTIVES

To evaluate the effects of fiberoptic bronchoscopy (FOB) on delivered volumes and pressures during mechanical ventilation, utilizing a lung model.

DESIGN

Bench study.

SETTING

Laboratory.

MATERIALS AND METHODS

Using varying-sized endotracheal tubes (ETTs), we ventilated a lung model at two levels of compliance utilizing different modes and parameters of ventilation. After establishing baseline measurements, the bronchoscope was inserted and measurements repeated.

MEASUREMENTS AND RESULTS

During controlled mechanical ventilation (CMV) with a preset high-pressure limit (HPL), tidal volumes (VTs) were reduced from 700 mL to 0 to 500 mL following insertion of the bronchoscope. Increasing the HPL to 120 cm H(2)O resulted in a VT of 40 to 680 mL. Changing from square to decelerating flow waveform resulted in no consistent difference in VT. Auto-positive end-expiratory pressure (auto-PEEP) of 0 to 41 cm H(2)O was present under most conditions. Higher rates and lower peak inspiratory flows were associated with higher levels of auto-PEEP. In the pressure-control (PC) mode, using a preset inspiratory pressure level (IP), VT was reduced from 700 mL to 40 to 280 mL following insertion of the bronchoscope. Maximum IP (100 cm H(2)O) increased VT to 260 to 700 mL. Auto-PEEP was less in the PC mode.

CONCLUSIONS

Extreme care must be taken when bronchoscopy is performed on a patient receiving mechanical ventilation. Extremely low VT and significant auto-PEEP may develop unless flow, respiratory rate, mode, and ETT size are carefully selected. The PC mode delivered more volume than did the CMV mode. When performing FOB during mechanical ventilation, the inside diameter of the ETT should be > or = 2.0-mm larger than the outside diameter of the bronchoscope to maintain volume delivery and minimize the development of auto-PEEP.

Induction of interleukin-8 release by lung epithelium with cystic fibrosis epithelial lining fluid is marginally affected by inhibitors of interleukin-1beta

Interleukin-1beta (IL-1beta) and neutrophil elastase (NE) are present in the epithelial lining fluid (ELF) of patients with cystic fibrosis (CF). Both factors activate surrounding cells including lung epithelial cells, causing release of IL-8, a potent chemoattractant for neutrophils. Previous studies showed up-regulation of IL-8 release by lung epithelial cells as a function of NE in CF; however, few studies addressed the relationship between IL-1beta and activation of lung epithelial cells in CF lungs. Confluent layers of A549 cells, a type II-like human lung epithelial cell line, were incubated overnight with IL-1beta (0-5 ng/ml) or NE (100 nM), and supernatants were analyzed for IL-8 by enzyme-linked immunosorbent assay (ELISA). Both IL-1beta and NE led to a significant increase in IL-8: 12.8 +/- 2.8 ng/ml and 0.8 +/- 0.3 ng/ml, respectively. Next, bronchoalveolar lavage (BAL) samples were obtained from one healthy adult volunteer and six patients with CF and measured for IL-8 and IL-1beta concentrations by ELISA. Both IL-8 (range 169.00 +/- 56.57 to 1742.04 +/- 338.98 pg/ml) and IL-1beta (range 0-24.26 +/- 0.52 pg/ml) were detected in CF specimens, whereas neither was detected in the volunteer's specimen. Normal and CF BALs then were incubated overnight at a 1:10 dilution with confluent A549 cells. Analysis by ELISA of cell-free supernatants revealed increased IL-8 production from cells stimulated with CF BALs only. Similar experiments were performed with BAL supernatants that had been incubated with soluble IL-1 type II receptor, soluble IL-1 receptor antagonist, or a peptide inhibitor of NE. Addition of IL-1 inhibitors had a marginal effect on the amount of IL-8 release after incubation with CF BAL samples, whereas inhibition of NE had no effect. Our results indicate that other factors present in ELF in CF account for IL-8 release from lung epithelial cells.

Quality assessment through patient self-report of symptoms prefiberoptic and postfiberoptic bronchoscopy

STUDY OBJECTIVE

To apply the principles of quality improvement to measure the frequency and severity of symptoms that result from fiberoptic bronchoscopy (FOB), and to identify opportunities to improve FOB practice by identifying factors about patients and the process of care that predict these symptoms.

DESIGN

Concurrent longitudinal cohort study.

PATIENTS

Four hundred ninety-three adult patients who underwent FOB.

MEASUREMENTS AND RESULTS

Patients completed questionnaires just prior to FOB and again at 48 h postprocedure. Patients were asked to rate the severity of nose pain, throat pain, swallowing pain, and chest pain, and the frequency of coughing, hemoptysis, phlegm, shortness of breath, wheezing, difficulty swallowing, fever, and chills. Symptom severity was reported on a four-point ordinal scale.

FINDINGS

Significant worsening was found for nose pain, throat pain, swallowing pain, and hemoptysis. Shorter patients experienced more throat pain and hemoptysis, and longer procedure time predicted nose pain and hemoptysis.

CONCLUSIONS

Bronchoscopy causes nose pain, throat pain, swallowing pain, and hemoptysis to a larger extent than previously has been recognized. There are opportunities to improve the patient experience with bronchoscopy by using smaller bronchoscopes in shorter patients, shortening the procedure length, and reanesthetizing the nares in longer procedures.