Bronchoscopy, Mediastinoscopy, and Thoracoscopy



Bronchoscopy, Mediastinoscopy, and Thoracoscopy


Alessia Pedoto

Paul M. Heerdt

Fun-Sun F. Yao





A. Medical Disease and Differential Diagnosis



  • How is the diagnosis of lung carcinoma made? What is your prediction for the most likely type of malignancy?


  • What are the less common manifestations of bronchogenic carcinoma?


  • The patient has a long history of cigarette smoking. What is the significance of this finding?


B. Preoperative Evaluation and Preparation



  • How would you evaluate the patient prior to surgery?


  • What are the pulmonary function guidelines that indicate an increased risk for morbidity and mortality?


C. Intraoperative Management



  • How would you premedicate, monitor, and anesthetize this patient?


  • How many types of bronchoscopes are available and what are the intraoperative considerations of each one?


  • What are the indications for cervical mediastinoscopy? Are there potential complications?


  • The decision was made to proceed with a thoracoscopic right middle lobectomy. How would this alter your management?


  • What are the indications for single-lung ventilation and how is it accomplished?


  • What are the contraindications to the use of double-lumen endotracheal tubes (DLTs)?


  • Would you use a right- or left-sided DLT?


  • How do you know that the tube is in the correct position?


  • How many types of bronchial blockers are available? What are the advantages and disadvantages of bronchial blockers?


  • How will systemic oxygenation be monitored during single-lung ventilation? What is the mechanism of pulse oximetry?


  • The patient was placed in the lateral decubitus position. Describe the effects of lateral positioning on pulmonary blood flow and respiration.


  • What is hypoxic pulmonary vasoconstriction (HPV)?



  • What are the effects of anesthetic agents on HPV and their clinical implications?


  • Discuss pulmonary blood flow distribution, shunt flow, and PaO2 (FIO2 = 1.0) during single-lung ventilation in the lateral position.


  • How could you improve oxygenation during single-lung ventilation?


  • A right middle lobectomy was performed. Would you extubate the trachea at the end of the procedure?


D. Postoperative Management



  • What are the immediate life-threatening complications that follow lobectomy or pneumonectomy?


  • Why is it important to control postoperative pain? How would you achieve this?


A. Medical Disease and Differential Diagnosis


A.1. How is the diagnosis of lung carcinoma made? What is your prediction for the most likely type of malignancy?

The initial presenting symptoms in patients with lung cancer are constitutional and nonspecific, mainly related to metastatic disease. Nonproductive cough, dyspnea, hemoptysis, and chest pain, along with an unresolved lung infiltrate on chest radiography, should suggest carcinoma. In the attempt to make early diagnosis, the American Cancer Society has issued preliminary guidelines for screening high-risk patients using low-dose computed tomography imaging. Recommended candidates include “apparently healthy” subjects aged between 55 and 74 years with a smoking history of at least 30 packs per year, who are current smokers or quit within the past 15 years. The main limitation of this test is the 23.3% incidence of false-positive results, which may lead to further testing including surgical biopsy. Biomarkers from large airway epithelial cells or buccal mucosal biopsies are being investigated and may represent early diagnostic options in the future. At the present time, the initial diagnostic and staging procedures are done in the operating room under general anesthesia. This includes flexible bronchoscopy with airway washings and brush biopsy, possibly followed by ultrasound-guided transbronchial biopsy (endobronchhial ultrasound [EBUS]) of the mediastinal lymph nodes. Additional areas for biopsy include palpable lymph nodes in the neck or axilla, needle aspiration biopsy, mediastinoscopy, and possibly exploratory thoracoscopy or thoracotomy. An extensive evaluation must be performed to exclude metastases which would contraindicate major surgery.

Cancers of the lung account for 16% of all malignancies and nearly 27% of cancer-related deaths worldwide. Bronchogenic carcinomas represent the vast majority of lung cancers in patients requiring surgical resection and can be classified into four major types: small cell, large cell, squamous cell, and adenocarcinoma. For surgical purposes, lung tumors are classified as non-small cell or small cell. The former are amenable to surgical resection, while the latter tend to be nonresectable and are treated medically.

The TNM classification is used in the staging of bronchogenic carcinomas and helps to predict the response to therapy. T designates tumor site, size, and local extent; N, the presence and location of regional lymph node involvement; and M, the presence of distal metastases beyond the ipsilateral hemithorax. In general, small cell carcinomas that spread beyond possible resection by the time of presentation are primarily managed with chemotherapy, with or without radiation, and lead to a 5-year survival of approximately 20%. In contrast, non-small cell cancers found to be localized at the time of presentation should be considered for primary resection. The 5-year survival can be as high as 85% for small tumors without regional lymph node involvement or metastases (stage I). Approximately 45% of patients present with circumscribed extrapulmonary disease or lymphatic spread to the ipsilateral mediastinal or subcarinal lymph nodes (stage IIIa). Their 5-year postresection survival is less than 20%.



Kasper DL, Fauci AS, Hauser S, et al, eds. Harrison’s Principles of Internal Medicine. 19th ed. New York: McGraw-Hill; 2015:506-522.


Kathuria H, Gesthalter Y, Spira A, et al. Updates and controversies in the rapidly evolving field of lung cancer screening, early detection, and chemoprevention. Cancers (Basel). 2014;6:1157-1179.

Spiro SG, Gould MK, Colice GL. Initial evaluation of patients with lung cancer: symptoms, signs, laboratory tests, and paraneoplastic syndromes: ACCP evidence-based clinical practice guidelines (2nd edition). Chest. 2007;132:149S-160S.

Wender R, Fontham ET, Barrera E Jr, et al. American Cancer Society lung cancer screening guidelines. CA Cancer J Clin. 2013;63:107-117.


A.2. What are the less common manifestations of bronchogenic carcinoma?

Other manifestations of lung tumors are primarily related to mass effects or altered metabolism. In addition to bronchial obstruction and possible postobstructive pneumonia, mass effects include invasion into the chest wall and pleura, compression of great vessels (e.g., superior vena cava syndrome) and heart, tracheobronchial displacement, paresis of the recurrent laryngeal or phrenic nerves and of the sympathetic chain. Pancoast syndrome can present with pain and upper extremity weakness secondary to invasion of the brachial plexus as well as the first and second thoracic and eighth cervical nerve roots. Recognized metabolic manifestations of small cell lung tumors include symptoms that resemble those of Cushing syndrome (from ectopic adrenocorticotropic hormone production), carcinoid syndrome, hypercalcemia and hypophosphatemia (resulting from ectopic parathyroid hormone or parathyroid hormone-related peptides), hypokalemia (caused by ectopic adrenocorticotropic hormone secretion), and hyponatremia (from inappropriate secretion of antidiuretic hormone and possibly atrial natriuretic factor). Neurologic paraneoplastic syndromes include Lambert-Eaton myasthenic syndrome, peripheral neuritis involving both motor and sensory components, cerebellar degeneration, retinopathy, limbic encephalopathy, and autonomic neuropathy. An autoimmune process has been suggested for these findings, and it seems to be more common in patients with limited disease.

Extrathoracic spread of the tumor can affect the bones, liver, adrenal glands, intra-abdominal and subcutaneous lymph nodes, brain, and spinal cord, contributing to the nonspecific presentation of the cancer.



Kasper DL, Fauci AS, Hauser S, et al, eds. Harrison’s Principles of Internal Medicine. 19th ed. New York: McGraw-Hill; 2015:506-522.

Spiro SG, Gould MK, Colice GL. Initial evaluation of patients with lung cancer: symptoms, signs, laboratory tests, and paraneoplastic syndromes: ACCP evidence-based clinical practice guidelines (2nd edition). Chest. 2007;132:149S-160S.


A.3. The patient has a long history of cigarette smoking. What is the significance of this finding?

Cigarette smoking still remains the leading cause of lung cancer in the United States. Tobacco exposure leads to chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema, and is strongly associated with an increased incidence of stroke, myocardial infarction, and cancer (lung, oral cavity, larynx, and esophagus). Pulmonary hypertension from chronic hypoxemia and subsequent cor pulmonale may also occur.

Eight percent to 17% of patients with lung cancer who are scheduled for surgical resection are still smoking at the time of surgery. Current tobacco use increases the risk of postoperative respiratory failure, pneumonia, aspiration, air leak, atelectasis, as well as 1-year mortality. Preoperative smoking cessation is strongly recommended, but it is unclear how long is needed to see a significant reduction in postthoracotomy complications. Carboxyhemoglobin concentrations decline substantially within 12 hours of smoking cessation. In patients undergoing thoracic surgery, the benefits of smoking cessation must be balanced with the risk of local tumor growth and metastatic spread, which may preclude resectability. Four weeks has been suggested as an acceptable time by several studies in this population. A combined approach including counseling and polypharmacology has been shown to increase the success rate and decrease relapses after hospital discharge.



Carson KV, Usmani ZA, Robertson TA, et al. Smoking cessation interventions for lung cancer patients. Lung Cancer Manage. 2013;2:61-74.

DeHoyos A, DeCamp M. Preoperative smoking cessation for lung resection patients. In: Ferguson MK, ed. Difficult Decision in Thoracic Surgery: An Evidence-Based Approach. 3rd ed. London: Springer-Verlag; 2014:85-98.


Kathuria H, Gesthalter Y, Spira A, et al. Updates and controversies in the rapidly evolving field of lung cancer screening, early detection, and chemoprevention. Cancers (Basel). 2014;6:1157-1179.

Mason DP, Subramanian S, Nowicki ER, et al. Impact of smoking cessation before resection of lung cancer: a Society of Thoracic Surgeons General Thoracic Surgery Database study. Ann Thorac Surg. 2009;88:362-370.

Pedoto A, Heerdt PM. Postoperative care after pulmonary resection: postanesthesia care versus intensive care unit. Curr Opin Anaesthesiol. 2009;22:50-55.

Wong J, Lam DP, Abrishami A, et al. Short term preoperative smoking cessation and postoperative complications: a systematic review and meta-analysis. Can J Anaesth. 2012;59:268-279.


B. Preoperative Evaluation and Preparation


B.1. How would you evaluate the patient prior to surgery?

Preoperative evaluation should investigate cardiac risks in case of perioperative cardiac disease, lung function, gas exchange capacity, and cardiopulmonary reserve. The main goal is to identify in advance those at risk for major postoperative complications and optimize their functional status. The first step should include a complete history, physical examination, and laboratory tests (e.g., complete blood count, basic metabolic profile, coagulation study, electrocardiogram, chest radiography, and computed tomographic imaging). A positive smoking history, especially if current, cough, sputum production, orthopnea, and dyspnea should be further investigated. An abnormal exercise tolerance, such as the inability to climb at least three flights of stairs or walk for 6 minutes, may indicate a patient with compromised cardiorespiratory function and unable to tolerate the stress of anesthesia and surgery. A brief review of symptoms, physical limitations, interval changes, and airway anatomy is usually performed before entering the operating room.

In addition to routine preoperative testing, patients scheduled for lung resection usually undergo pulmonary function testing to help define the relative risks of the planned resection. Respiratory function can be assessed by:



  • Respiratory mechanics: evaluated via forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and the ratio between residual volume and total lung capacity (RV/TLC). Flow-volume loops may be helpful to document the location of the obstruction (small vs. large airway) and its severity. Post bronchodilator FEV1 and FEV1/FVC paired with clinical symptoms are used to determine the severity of COPD.


  • Cardiopulmonary reserve: evaluated with maximal oxygen uptake (VO2 max), stair climbing, 6-minute walk, and shuttle walk. VO2 max is the gold standard for aerobic capacity and cardiorespiratory fitness. Patients with VO2 max value less than 10 mL/kg/min are at increased risk for postoperative morbidity and mortality.


  • Lung parenchymal function: Diffusing lung capacity for carbon monoxide (DLCO), partial pressure of oxygen in the arterial blood (PaO2), and partial pressure of arterial carbon dioxide (PaCO2). Predicted postoperative DLCO and FEV1 less than 40% to 44% are significant independent predictors for increased postoperative morbidity and mortality.



Brunelli A, Kim AW, Berger KI, et al. Physiologic evaluation of the patient with lung cancer being considered for resectional surgery: diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest. 2013;143(suppl 5):e166S-e190S.

Licker M, Triponez F, Diaper J, et al. Preoperative evaluation of lung cancer patients. Curr Anesthesiol Rep. 2014;4:124-134.

Ravenel JG, ed. Lung Cancer Imaging. New York: Springer Science; 2013:69-78.


B.2. What are the pulmonary function guidelines that indicate an increased risk for morbidity and mortality?

The reported mortality from lung resection is between 2% and 4%, mainly as a result of pneumonia, respiratory failure, bronchopleural fistula, empyema, and pulmonary embolism. Respiratory insufficiency occurs in approximately 5% of patients following lung resection
and is associated with a 50% mortality rate. Advanced age and the increased incidence of concomitant nonpulmonary disease seem to contribute to this outcome. An increased risk of postoperative complications can be predicted by the following:








TABLE 2.1 Minimal Pulmonary Function Test Criteria for Various-Sized Pulmonary Resections















































TEST


UNIT


NORMAL


PNEUMONECTOMY


LOBECTOMY


BIOPSY OR SEGMENTAL


MBC


L/min


>100


>50


>40


>25


MBC


Percentage predicted


100%


>50%


>40%


>25%


FEV1


Liters


>4


>2.1-1.7


>1.2-1.0


>0.6-0.9


FEV1


Percentage


>80% FVC


>50% FVC


>40% FVC


>40% FVC


FEV25%-75%


Liters


>2


>1.6


>0.6-1.6


>0.6


FEV1, forced expiratory volume in first second; FEV25%-75%, forced expiratory volume from 25% to 75% of forced vital capacity; FVC, forced vital capacity; MBC, maximum breathing capacity.




  • Spirometry: Spirometric parameters, such as FEV1/FVC ratio and FEV1 (reflective of the degree of airway obstruction), as well as static volumes (such as inspiratory and TLC), are used to define the severity of COPD. Several studies have indicated a strong correlation between predicted postoperative FEV1 and DLCO and a respective increase in morbidity and mortality, especially for open procedures and extensive dissection. Concerning values are summarized in Table 2.1.


  • Arterial blood gases: Historically, hypercapnia (PaCO2 greater than 45 mm Hg) was considered an exclusion criterion for lung resection. However, no independent correlation has been found with an increased mortality. Patients who are hypercapnic often have a low predicted postoperative FEV1 and an abnormal exercise capacity, which preclude surgery. Preoperative hypoxemia (PaO2 less than 50 mm Hg, and percentage of available hemoglobin saturated with oxygen [SaO2] less than 90%) has been associated with an increased risk of postoperative complications. However, baseline hypoxemia can be the result of ventilatory mismatch caused by obstructive tumors that once resected may theoretically improve gas exchange.

Other factors influencing outcome include patient comorbidities and functional status, the extent and location of the proposed surgical resection, and whether the patient has undergone preoperative induction chemotherapy. An improvement in both surgical and anesthetic techniques has broadened the criteria for surgical respectability. As evident from lung volume reduction studies, patients with severely impaired pulmonary function (e.g., FEV1 less than 1 L) can still undergo surgical resection under general anesthesia without prohibitive risk for postoperative complications. Moreover, the development of minimally invasive surgical techniques has raised the question of whether standard selection criteria should always be adopted.

Emphasis has been directed toward integrating multiple aspects of the preoperative evaluation (e.g., respirometry, ventilation-perfusion scanning, extent of planned resection, patient functional status) into the estimate of postoperative function. Better postoperative analgesia techniques, early ambulation, and thromboprophylaxis have all contributed to improve outcomes after major lung resection in patients at high risk.



Boffa DJ, Allen MS, Grab JD, et al. Data from The Society of Thoracic Surgeons General Thoracic Surgery database: the surgical management of primary lung tumors. J Thorac Cardiovasc Surg. 2008;135:247-254.

Matsubara Y, Takeda S, Mashimo T. Risk stratification for lung cancer surgery: impact of induction therapy and extended resection. Chest. 2005;128:3519-3525.

Miller RD, ed. Miller’s Anesthesia. 10th ed. New York: Churchill Livingstone; 2015:1942-2006.

Pedoto A, Heerdt PM. Postoperative care after pulmonary resection: postanesthesia care versus intensive care unit. Curr Opin Anaesthesiol. 2009;22:50-55.



C. Intraoperative Management


C.1. How would you premedicate, monitor, and anesthetize this patient?

Current practice in most institutions dictates that patients arrive at the hospital the day of surgery; thus, traditional oral or parenteral premedication before transport to the operating room is largely obsolete. Bronchoscopy and mediastinoscopy are generally ambulatory procedures, necessitating a relatively rapid hospital discharge. Because lung resection in this patient is only a possibility, intravenous midazolam immediately on entry into the operating room would seem appropriate for anxiolysis and subsequent amnesia. If not contraindicated, a small intravenous dose (0.2 mg) of glycopyrrolate can be considered as an antisialagogue, particularly in patients who smoke.

EBUS-guided lymph node biopsy has become more popular in the past decade, as a minimally invasive highly accurate alternative to cervical mediastinoscopy for staging of lung cancer. It can be performed either via the esophagus or the trachea under sedation or general anesthesia. The former is indicated for a limited number of biopsies, whereas the latter works better in case of complete staging of the mediastinum. On-site cytologic exam is usually performed during the procedure. Mediastinal, hilar, lobar, and interlobar lymph nodes are accessible with this technique with a complication rate of 1.4%. Coughing (if the airway is not adequately topicalized) and bronchospasm are potential intraoperative complications. The incidence of pneumothorax is rare and depends on the location of the lymph node to biopsy rather than the type of anesthesia and the ventilation modality. Bleeding is also a rare instance, therefore not requiring aggressive reversal of anticoagulation as for mediastinoscopy.

Cervical mediastinoscopy is now reserved for small lymph nodes not readily accessible via EBUS. During mediastinoscopy, intermittent compression or occlusion of the innominate artery can occur. Therefore, the blood pressure cuff should be placed on the left arm and the pulse oximeter on the right hand. In the case of innominate artery compression, a damping of the pulse oximetry trace will be evident while blood pressure measurements will remain accurate. Although rare, injury to vascular structures (such as the azygos veins and innominate artery) can occur, potentially necessitating sternotomy. Patient positioning and placement of electrocardiography leads should be considered accordingly. Arterial access is not routinely used for this procedure unless the patient has clinical indications for continuous hemodynamic monitoring. In this case, the catheter should be placed in the left radial artery as well to avoid falsely low readings related to innominate artery compression. Body temperature should be monitored, and a warming blanket applied. Despite the potential of being a short procedure, hypothermia can occur, especially in the elderly patients. Induction, maintenance of anesthesia, and muscle relaxation can be achieved with relatively short-acting agents. Propofol is usually used for induction of general anesthesia followed by rocuronium, vecuronium, or cisatracurium to facilitate tracheal intubation via a singlelumen endotracheal tube (ETT). Anesthesia can be maintained with a potent inhalational agent in oxygen or air, if oxygen saturation tolerates it. Two to 3 µg per kg of fentanyl often provides sufficient analgesia for the procedure. Local anesthetic can be infiltrated in the wound by the surgeon at the beginning or at the end of the procedure. Nonsteroidal antiinflammatory drugs (NSAIDs) are used by some providers as adjuvant agents; nevertheless, the potential for bleeding in a closed space in ambulatory patients should be considered. Finally, many clinicians choose to avoid the use of nitrous oxide because of the potential for the mediastinoscope to enter the pleural space and create a pneumothorax.



Eapen GA, Shah AM, Lei X, et al. Complications, consequences, and practice patterns of endobronchial ultrasound-guided transbronchial needle aspiration: results of the AQuIRE registry. Chest. 2013;143:1044-1053.

Harris CL, Toloza EM, Klapman JB, et al. Minimally invasive mediastinal staging of non-small-cell lung cancer: emphasis on ultrasonography-guided fine-needle aspiration. Cancer Control. 2014;21:15-20.

Molins L, Fibla JJ, Pérez J, et al. Outpatient thoracic surgical programme in 300 patients: clinical results and economic impact. Eur J Cardiothorac Surg. 2006;29:271-275.

Rami-Porta R, Call S. Invasive staging of mediastinal lymph nodes: mediastinoscopy and remediastinoscopy. Thorac Surg Clin. 2012;22:177-189.

Slinger P, ed. Perioperative lung injury. In: Slinger P, ed. Principle and Practice of Anesthesia for Thoracic Surgery. New York: Springer; 2011:201.



C.2. How many types of bronchoscopes are available and what are the intraoperative considerations of each one?

Four types of bronchoscopes are currently in use: flexible fiberoptic, bronchoscopy (EBUS), rigid ventilating, and rigid Venturi.

The flexible fiberoptic bronchoscope can be used either in sedated patients under local anesthesia (allowing examination of vocal cords movements) or under general anesthesia with a supraglottic airway or an ETT. For the awake or sedated examination, viscous lidocaine can be gargled to anesthetize the upper airway, and a 2% or 4% lidocaine solution inhaled via nebulizer mask to reach the lower airway. Bilateral superior laryngeal nerve blocks or transtracheal block can be added, however, not as popular as in the past due to the potential complications. Intravenous sedation can be achieved with 0.5-mg increments of midazolam, 10 µg of remifentanil boluses or a propofol infusion. Alternatively, dexmedetomidine (as a bolus of 0.5 to 1 µg per kg over 10 minutes followed by a continuous infusion of 0.2 to 1.5 µg/kg/hr) can also be used; its main advantage consisting of amnesia and vagolysis without impaired ventilation. When compared to propofol, the main disadvantage seems to be the prolonged recovery time, limiting its use in the ambulatory setting. If the oropharynx is adequately anesthetized, a supraglottic airway can be inserted without discomfort in sedated patients and used to assist ventilation at higher FIO2 concentrations.

EBUS can be done with either sedation or general anesthesia, depending on the number and locations of the lymph nodes to biopsy. Good topical anesthesia is paramount to prevent coughing and bronchospasm, independently of the technique used. The EBUS bronchoscope is a 6.9-mm outer diameter flexible bronchoscope with a latex balloon tip, coupled with a 7.5-MHz convex ultrasound probe. When the balloon is inflated with normal saline, it allows a tight adhesion to the airway wall facilitating ultrasound identification of the lymph nodes. A 21-gauge needle is used through a dedicated channel of the bronchoscope for real time biopsy. Color Doppler is available to differentiate the lymph nodes from vascular structures. In the sedated patient, or if a supraglottic airway device is used, particular attention should be used to avoid vocal cord trauma due to the positioning of the optical view at a 30-degree angle. Intravenous steroids may be used to prevent inflammation and edema. In nonintubated patients, local anesthetic toxicity may result from larger doses used to tolerate the longer procedure and abolish the cough reflex. If ETT is used, an 8.5 mm internal diameter (ID) ETT is recommended to accommodate the bronchoscope and ventilate. In the presence of precarinal lymphadenopathy, the ETT may need to be placed high in the trachea, leaving the balloon between vocal cords. Trauma may occur in case of prolonged procedures and in the absence of paralysis. Other complications include pneumo- and hemomediastinum, pneumothorax, mediastinitis, and bacteremia.

Rigid bronchoscopy usually necessitates general anesthesia. Although spontaneous ventilation has been used, the risk of tracheal trauma is high with coughing. If not contraindicated, muscle relaxation is usually used. The rigid ventilating bronchoscope has a side-port adapter that can be attached to either the anesthesia machine or the jet ventilator, allowing the delivery of a high flow rate. A variable air leak usually exists around the bronchoscope, so high flow rates of inspired gases or packing of the oropharynx are needed. Significant loss of volatile anesthetic into the operating room environment needs to be considered; thus, the use of total intravenous technique is a good alternative.

The rigid Venturi-effect bronchoscope relies on an intermittent high-flow (20 to 60 L per minute), high-pressure (50 psi) oxygen jet to entrain air and insufflate the lungs. The jet is delivered through a reducing valve (25 psi) into a 16- or 18-gauge needle inside and roughly parallel to the lumen of the bronchoscope. Major disadvantages of this bronchoscope are the lack of control of the inspired oxygen concentration and the inability to administer inhaled anesthetics. Accordingly, anesthesia should be maintained by intravenous techniques. Inadequate ventilation can result in hypercapnia.

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Mar 18, 2021 | Posted by in ANESTHESIA | Comments Off on Bronchoscopy, Mediastinoscopy, and Thoracoscopy

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