Mark R. Bowling

The effect of general anesthesia versus intravenous sedation on diagnostic yield and success in electromagnetic navigation bronchoscopy.

Background:Navigational bronchoscopy is utilized to guide biopsies of peripheral lung nodules and place fiducial markers for treatment of limited stage lung cancer with stereotactic body radiotherapy. The type of sedation used for this procedure remains controversial. We performed a retrospective chart review to evaluate the differences of diagnostic yield and overall success of the procedure based on anesthesia type. Methods:Electromagnetic navigational bronchoscopy was performed using the superDimension software system. Once the targeted lesion was within reach, multiple tissue samples were obtained. Statistical analysis was used to correlate the yield with the type of sedation among other factors. A successful procedure was defined if a diagnosis was made or a fiducial marker was adequately placed. Results:Navigational bronchoscopy was performed on a total of 120 targeted lesions. The overall complication rate of the procedure was 4.1%. The diagnostic yield and success of the procedure was 74% and 87%, respectively. Duration of the procedure was the only significant difference between the general anesthesia and IV sedation groups (mean, 58 vs. 43 min, P=0.0005). A larger tumor size was associated with a higher diagnostic yield (P=0.032). All other variables in terms of effect on diagnostic yield and an unsuccessful procedure did not meet statistical significance. Conclusions:Navigational bronchoscopy is a safe and effective pulmonary diagnostic tool with relatively low complication rate. The diagnostic yield and overall success of the procedure does not seem to be affected by the type of sedation used.

Pulmonary Extramedullary Hematopoiesis

Extramedullary hematopoiesis (EMH) is the formation and development of blood cells outside of the bone marrow. Of particular interest to chest physicians and radiologists is the occurrence of EMH in the lungs and pleura. There have been several reports of patients presenting with pulmonary EMH published in the literature and the majority are due to a secondary process, such as myeloproliferative disorders, hemolytic anemias, hereditary spherocytosis, and Gaucher disease. We present a case report of pulmonary EMH and a review of the literature concentrating on the etiology, clinical presentation, pathophysiology, diagnosis, and therapy for this uncommon disorder.

Current Management of Salicylate-Induced Pulmonary Edema:

Salicylate-induced pulmonary edema (SIPE) can occur in both acute and chronic users of aspirin or salicylate products. The medical history, especially when it reveals the use of salicylates, is critical when considering this diagnosis. Unfortunately, the neurologic and systemic effects of salicylate toxicity may hinder the ability to obtain a reliable medical history. SIPE should be considered in patients who present with pulmonary edema and neurological changes, anion-gap metabolic acidosis, or possible sepsis. Some patients may be treated for “pseudosepsis” or other conditions, thereby delaying the diagnosis of salicylate intoxication. Misdiagnosis and possibly delayed diagnosis of SIPE can lead to a significant increase in morbidity and mortality. Serum and urine alkalinization by administration of intravenous sodium bicarbonate are commonly utilized therapeutic strategies. Finally, hemodialysis is a therapy which should be considered early in the course of treatment. The objective of this review was to emphasize the importance of rapid diagnosis and appropriate treatment in patients with SIPE, and summarize the current literature as it relates to the adult population.

Endobronchial ultrasound in the evaluation of lung cancer: a practical review and cost analysis for the practicing pulmonologist.

Flexible bronchoscopy remains an important tool in the staging, diagnosis, and treatment of primary and metastatic lung malignancies. Endobronchial ultrasound is a new technology utilized with bronchoscopy that has been shown to identify bronchial wall invasion by malignant tumors, aid in the fine needle aspiration of peripheral lung lesions and mediastinal/hilar lymph nodes, and determine the course of treatment in patients with pulmonary carcinoma in situ. The decision to invest both time and money in this technology is determined by several factors such as the cost of the equipment, reimbursement for the procedure, availability of training, the number of bronchoscopies one performs in a year, and access to endoscopic ultrasound and mediastinoscopy. This article reviews the literature to determine the utility of endobronchial ultrasound in the management of patients with lung cancer and to provide information to practicing pulmonologists that may aid in determining whether and where this technology fits into their clinical armamentarium.

Perception versus Reality: The Measuring of Pleural Fluid pH in the United States

Background: Pleural fluid pH measured by a blood gas analyzer is the only recommended method of pH measurement to guide management for patients with parapneumonic pleural effusions. Not all hospitals use blood gas analyzers for pleural fluid pH determination and it is unknown if physicians are aware of this problem. Objective: To determine if a discrepancy exists between the modality used for measuring pleural fluid pH and how physicians believe it is measured. Methods: We surveyed pulmonologists randomly across the USA by e-mail inquiring how they thought pleural fluid pH was measured at their laboratory. We then independently contacted the laboratory and asked how pleural fluid pH was actually measured. Results: Two hundred and sixty-seven pulmonologists completed the survey. Eighty-six percent of the pulmonologists use pleural fluid pH to manage complicated parapneumonic effusions. Forty-three percent did not recognize blood gas analyzer solely as the most accurate and validated method. Thirty-nine percent of the physicians who use pleural pH to manage effusions and believe that blood gas analyzers are the most accurate were wrong in their assumption that their laboratory was using this tool for pleural pH measurement. Conclusions: Whether it is due to inaccurate knowledge or a perception of how pleural fluid pH is tested, a significant number of pulmonologists, when treating complicated parapneumonic effusions, may be making management decisions based on erroneous information.

Methemoglobinemia in bronchoscopy: a case series and a review of the literature.

Background:Methemoglobinemia results from oxidation of ferrous iron to ferric iron within the hemoglobin molecule. This molecule cannot bind oxygen and increases the affinity of normal hemoglobin for oxygen, which results in decreased oxygen offloading in peripheral tissues. At elevated levels, methemoglobinemia can cause dyspnea, cyanosis, and even death. Common local anesthesia agents have been correlated with methemoglobinemia. Bronchoscopy is a commonly performed clinical procedure which uses topical application of these anesthetics to provide patient comfort. Methylene blue is an agent thought to help reverse the effects of methemoglobinemia by facilitating the methemoglobin reductase system. Methods:Using multiple search engines including PubMed and the Cochrane Database, available data on cases of methemoglobinemia after bronchoscopy were pooled. Adult and pediatric cases were considered. Results:Eleven cases were identified. Cases occurred from 1977 until present. Data gathering was complicated by the fact that a consistent reporting system was not used across cases. Arterial blood gas data and CO-oximetry reported levels of methemoglobin were reported where available. No patients died from methemoglobinemia. The most common finding across all patients was decreased peripheral oxygen saturation. Cyanosis was also frequently reported. There was a disparity between the low peripheral oxygen saturation which was reported and the pO2 on the arterial blood gas. Dose and type of anesthetic agent varied widely across studies. Conclusions:Using topical anesthetic during bronchoscopy appears relatively safe. No fatalities from methemoglobinemia after bronchoscopy have been reported. A high suspicion for methemoglobinemia is required in patients who develop hypoxia or cyanosis postprocedurally. Access to CO-oximetry can confirm the diagnosis but the clinical picture is often sufficient to proceed with methylene blue treatment or observation, based on how severely the patient is affected. Patients who return to baseline can be considered for discharge home.

Bronchoscopy in the Diagnosis of Wegener Granulomatosis

Wegener granulomatosis (WG) is the most common antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Diagnosis often relies on a combination of clinical and histologic findings, with open lung biopsy considered the gold standard for confirmation of pulmonary involvement. We review the existing literature to determine whether fiberoptic bronchoscopy with endobronchial biopsy or transbronchial lung biopsy is an acceptable alternative to this invasive procedure in establishing the diagnosis of Wegener granulomatosis.

The Utility of Bronchoscopy for the Placement of Fiducial Markers for Stereotactic Body Radiotherapy

Stereotactic body radiotherapy is a common method to treat early-stage lung cancer in nonoperable patients. Many of these devices rely on fiducial markers to help guide the therapy and must be placed in or around the target lesion. This review will focus on the utility of bronchoscopy for placing these markers.

Going Off Road: The First Case Reports of the Use of the Transbronchial Access Tool With Electromagnetic Navigational Bronchoscopy.

The ability to reach the peripheral pulmonary nodule/mass with bronchoscopy has improved greatly over the past several years with the use of Electromagnetic navigational bronchoscopy; however, many of these lesions are unable to be adequately sampled due to their location outside the bronchial airways. We report the first use of the transbronchial access tool that creates a pathway from the bronchial airway through the lung parenchyma into the targeted lung abnormality.

Updates in Advanced Diagnostic Bronchoscopy: Electromagnetic Navigational Bronchoscopy Chasing the Solitary Pulmonary Nodule

Evaluation of the solitary pulmonary nodule has been limited with standard bronchoscopic approaches. The addition of advanced imaging, endobronchial ultrasound and virtual bronchoscopy has improved the bronchoscopic assessment of these lesions. Electromagnetic navigational bronchoscopy is one of the newer devices that creates a 3-dimensional reconstruction of the patient’s anatomy based on a computed tomography scan of the chest, which with electromagnetic technology can combine the virtual image with the patient’s actual anatomy at the time of the procedure and thus guide tissue collection from the pulmonary nodule. This review focuses on the utility of electromagnetic navigational bronchoscopy in the evaluation of the pulmonary nodule, examines all available literature, and discusses the various types and differences between the navigational systems.