Oxygen insufflation through the bronchoscope channel for sedation-induced hypoxia: safe and effective

Objectives: To evaluate both efficacy and safety parameters for insufflation through the bronchoscope as a method of recovery from sedation-induced hypoxia. To explore parameters applicable to use in human beings using an animal model. Materials and methods: Two adult pigs were sedated enough to depress respiratory drive. The effects of insufflation at 15 l/min (the upper limits of flow that might be used clinically) were then evaluated. Pressure and volume responses to bronchoscopy during intubation and without an endotracheal tube in place were recorded. Several assays were performed for each scenario, with each animal acting as its own control. Recovery from hypoxemia using insufflation was compared with recovery using mechanical ventilation. Results: Insufflation was effective, with rapid increases in fraction of inspired oxygen (FIO 2 ), saturation, and partial pressure of arterial oxygen (PaO 2 ). The rate of recovery using insufflation was faster than that from institution of mechanical ventilation. Insufflation in an intubated animal with cuff inflated led to a rapid and dangerous rise in pressure. With balloon deflated, there were no adverse pressure consequences from insufflation via the endotracheal tube at a rate of 15 l/min. Conclusion: Insufflation through the bronchoscope for episodes of sedation-induced hypoxia should be safe and effective as long as not delivered within a closed system

A novel technique of needle setting for curvilinear endobronchial ultrasound: Improved efficiency with no cost

Background: Standard instructions for biopsy using the convex curvilinear endobronchial ultrasound scope include visualization and adjustment of the sheath housing the biopsy needle before every puncture. In our practice, we pre-set this relationship before inserting the endobronchial ultrasound scope and leave it fixed for every puncture. Objective: We postulated that this approach is more efficient than repeated re-adjustment and aimed to show that it would not increase the frequency of endobronchial ultrasound scope damage. Methods: Retrospective review of every biopsy using the endobronchial ultrasound scope over a 6-year period with documentation of damages and costs. Results: There were 15 scope damages out of 1792 procedures (0.8%). Eight damages were determined to be due to needle damage, one due to patient bite, three due to Williams airway abrasions, and three were camera failures. All damages occurred during the first 5 years of the study. Costs totaled US$138,725, for an average of US$23,120 per year. This rate of damages appears to be similar to or lower than that reported when standard instructions are followed. Conclusion: Pre-setting of the biopsy needle when the endobronchial ultrasound scope is used leads to greater efficiency and no increase in scope damages

Endobronchial valves for bronchopleural fistula: pitfalls and principles

Background: Placement of endobronchial valves for bronchopleural fistula (BPF) is not always straightforward. A simple guide to the steps for an uncomplicated procedure does not encompass pitfalls that need to be understood and overcome to maximize the efficacy of this modality. Objectives: The objective of this study was to discuss examples of difficult cases for which the placement of endobronchial valves was not straightforward and required alterations in the usual basic steps. Subsequently, we aimed to provide guiding principles for a successful procedure. Methods: Six illustrative cases were selected to demonstrate issues that can arise during endobronchial valve placement. Results: In each case, a real or apparent lack of decrease in airflow through a BPF was diagnosed and addressed. We have used the selected problem cases to illustrate principles, with the goal of helping to increase the success rate for endobronchial valve placement in the treatment of BPF. Conclusions: This series demonstrates issues that complicate effective placement of endobronchial valves for BPF. These issues form the basis for troubleshooting steps that complement the basic procedural steps

Evaluation of technetium pertechnetate as a radionuclide marker of pulmonary aspiration of gastric contents in rabbits

At present, there is no sensitive and specific test to confirm the clinical impression that a respiratory disorder is due to aspiration of gastric contents. Since intravenous technetium pertechnetate (99mTcO4-) has been shown to be safe, actively concentrated in the gastrointestinal tract, and secreted into gastric juice, we sought to determine whether 99mTcO4-, when given intravenously, is suitable to detect pulmonary aspiration of small amounts of gastric contents in rabbits. Biodistribution studies over 24 h revealed that 99mTcO4- persistently appeared in the stomach, thyroid, and salivary glands and did not appear in the lungs. Pharmacokinetic studies showed that 99mTcO4- was rapidly picked up by the stomach wall and secreted promptly into the stomach lumen and that the stomach wall persistently secreted 99mTcO4- into stomach contents for 24 h. By injecting 99mTcO4- through an intratracheal catheter in order to simulate aspiration, the radioactive threshold for imaging intrapulmonary 99mTcO4- was determined to range between less than 0.5 microCi and 2 microCi, depending on the amount of background activity in the blood pool. By measuring the radioactivity in stomach contents (microCi/g), over 24 h after intravenous injection of 2 mCi of 99mTcO4-, we were able to calculate the amount of aspirated stomach contents that our technique should reveal at various time points. We concluded from this preliminary feasibility study that 99mTcO4-, when given intravenously, is suitable to detect pulmonary aspiration of small amounts (less than or equal to 4 ml for 8 h after an intravenous dose of 2 mCi) of gastric contents in human patients. Since our biodistribution studies show that saliva as well as stomach contents are potential sources for any aspirated 99mTcO4-, how to distinguish aspiration of oropharyngeal from stomach contents remains to be determined. It also remains to be determined how long 99mTcO4- remains in the lungs after it has been instilled; clearance that is too rapid significantly decreases the ability of this agent to reveal aspiration

A bronchoscopic approach to benign subglottic stenosis

Objectives: Subglottic stenosis is an abnormal narrowing of the tracheal lumen at the level of subglottis (the area in between the vocal cords and the cricoid cartilage). It can cause significant symptoms due to severe attenuation of airflow. We describe our experience in alleviating symptoms by addressing the stenosis using fibreoptic bronchoscopic methods. Methods: We report all concurrent cases performed between September 2015 and July 2016. We use a combination of balloon dilation, electro-surgery knife to dilate and incise stenotic segments followed by steroid injection to modulate healing. Results: We treated 10 patients in the study period, 8 of which were women. A total of 39 procedures were performed on these patients during this period. Gastro-esophageal reflux was the most common comorbidity associated with stenosis. The majority of the patients required more than 2 therapeutic procedures, but none required more than 4 procedures. There were no complications. Conclusion: Tracheal stenosis and in particular subglottic stenosis is a recurrent process and its management requires extensive collaboration amongst treating specialties. Our technique of steroid injection after dilation of the stenosis was effective in symptom control and decreased the number of repeat procedures