Endobronchial ultrasound–guided transbronchial needle aspiration (EBUS-TBNA) has emerged as the initial diagnostic modality of choice in sampling mediastinal lymph nodes of varied etiology.1 Its use has emerged from staging of lung cancer to being a diagnostic modality of choice for evaluation of mediastinal lymphadenopathy due to extrathoracic malignancies and benign etiologies.2,3 Within a decade of its inception, the minimal invasive procedure has become available worldwide, including in the developing nations. EBUS-TBNA is also performed in institutions with an academic setting in all parts of the world and is now incorporated in pulmonology training programs worldwide.4,5 The extensive use of EBUS-TBNA has facilitated further understanding of the procedural characteristics in terms of its anesthetic technique, diagnostic yields, and complications.
Moderate sedation in diagnostic flexible bronchoscopy is encouraged in all patients unless contraindicated or refused by the patient.6 It is safe and increases patient satisfaction.6,7 A practice of moderate sedation achieved with short-acting benzodiazepine and an opioid to achieve moderate sedation is currently recommended, with propofol being a reasonable alternative to combined sedation with benzodiazepine and opioid in flexible bronchoscopy.6,8 Bronchoscopist-guided sedation in flexible bronchoscopy is an accepted form of practice in which an anesthesiologist is not available.6 The sedation practices in EBUS-TBNA, to a certain extent, have been extrapolated from flexible bronchoscopy procedures.
Flexible bronchoscopy and EBUS-TBNA are typically performed in an outpatient setting. Anesthesia for EBUS-TBNA is more diverse and is an area for active research compared with flexible bronchoscopy. EBUS-TBNA has been reported to be performed under moderate sedation, deep sedation, or general anesthesia with artificial airways.9–11 The patient satisfaction scores have been similar for EBUS-TBNA with different levels of sedation.11,12 The sedation practices in EBUS-TBNA vary widely among institutions on the basis of local practices.11 Large prospective studies on the impact of anesthesia on diagnostic yield and complications of EBUS-TBNA are still lacking.
Bronchoscopist-guided sedation in EBUS-TBNA and its impact on diagnostic yield has not been reported earlier. The large retrospective study by Dhooria and colleagues highlight the feasibility, safety, and impact of bronchoscopist-guided moderate sedation on the diagnostic yield of EBUS-TBNA in a tertiary teaching center in a resource-limited setting.13 The anesthetic agents were administered by a trained technician as guided by the bronchoscopist. The study reports a similar complication rate as the large AQuIRE study and an acceptable diagnostic yield of EBUS-TBNA.13,14 The operators were at different phases of their learning curves as the procedures were also performed by pulmonary fellows.13 The diagnostic yield was lower in patients who suffered complications.13 The unavailability of an anesthesiologist in their high-volume bronchoscopy suite is cited as the reason for their practice pattern.13 This study highlights the safety and feasibility for smaller centers to perform EBUS-TBNA in which the limitation of anesthesiologists’ unavailability is a concern. The study raises questions on certain unconventional practices that have been reported. Moderate sedation was achieved by midazolam and pentazocine based on their institutional formulary in the study.13 Pentazocine is an approved opioid additive in surgical anesthesia. There is a lack of data on the usage of pentazocine during sedation for bronchoscopy. The unavailability of the Ramsay score in the majority of study patients is a major limitation.13 It raises a concern of monitoring and scoring by bronchoscopists in the absence of an anesthesiologist. The study reports the safety of premedication with an injectable anticholinergic as routine practice to reduce airway secretions in the EBUS-TBNA.13 However, the complication of arrhythmia is also mentioned in 3 patients without a predisposing cause.13 The British Thoracic Guidelines do not recommend the use of anticholinergic premedication before bronchoscopy.6
The type of personnel administering sedative drugs is as varied as the grades of sedation in EBUS-TBNA. Nurse-administered anesthesia has been shown to be safe for pulmonary endoscopies.8,15 Bronchoscopist-guided nurse-administered propofol infusion in EBUS-TBNA is also reported; however, separate protocols and training may be required.15,16 In the study by Dhooria et al,13 a trained technician administered anesthesia under the guidance of an additional bronchoscopist in the suite. This can be a challenge in situations in which an additional bronchoscopist or a technician is unavailable. The technician who assists in EBUS-TBNA may not be able to administer sedative drugs simultaneously. Also, even an experienced bronchoscopist may not be able to monitor, guide anesthesia, and perform the EBUS-TBNA procedure simultaneously because of a phenomenon called “bronchoscopist’s hypnosis.”17
The disadvantages of anesthesiologist-guided sedation are the increasing cost of an otherwise inexpensive procedure and the nonavailability of an anesthesiologist.18 However, there are more advantages to this practice pattern. Monitoring of the patient, sedation administration, and airway management in case of refractory hypoxemia define the valuable role of an anesthesiologist during bronchoscopy. The study conducted by Dhooria and colleagues describes a common scenario in a tuberculosis endemic country where EBUS-TBNA is predominantly used as a diagnostic tool in the evaluation of mediastinal lymphadenopathy than for staging of lung cancer.5,13,19 In this setting, this procedure may not last as long as lung cancer staging with EBUS-TBNA, as it requires sampling of multiple lymph node stations. Bronchoscopist-guided sedation during EBUS-TBNA performed for lung cancer staging is not yet described. Sedation requirements and risk stratification may vary in the elderly and in patients with comorbidities such as renal and hepatic affection. The sedation requirements are higher in transplant recipients, intravenous drug abusers, patients with HIV, and those already on opioids, benzodiazepines, or rifampin.7,20,21 In their study, Dhooria et al13 do not describe the comorbidities of their study population.
There are advantages and disadvantages to both anesthesiologist-guided and bronchoscopist-guided sedation. The standardization of the type of sedation and impact of usage of artificial airways remain the unmet needs in EBUS-TBNA. The clinical condition of the patient, the duration of the procedure, and operator comfort should be considered before the choice of sedation is made. Apart from costs and availability, anesthesiologist-guided sedation has potential advantages for patient safety and operator comfort. The bronchoscopist-guided sedation in EBUS-TBNA offers hope to pulmonologists in secondary centers where availability of an anesthesiologist is uncertain; however, a trained technician is nevertheless required. Thus, the pitcher can be a hitter, but if one is playing a major league game utilizing a designated hitter instead of the pitcher could be a safer bet!
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