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Fiber-Optic Bronchoscopy
C H A P T E R
1 Fiber-Optic Bronchoscopy Adrian Crutu, Amir Hanna and Pierre Baldeyrou Interventional Bronchoscopy Unit, Division of Thoracic Surgery and Lung Transplantation, Marie Lannelongue Hospital, Paris, France
The complementary information collected through bronchoscopy, in addition to the physical and radiological examination, is very important that it has become an essential tool in the diagnosis and evaluation of the majority of bronchopulmonary pathologies. The role of bronchoscopy has and will continue to increase over the coming years, but semiology is the same, whether we use flexible or rigid bronchoscope. An optimal semiological analysis will lead to the most appropriate therapeutic intervention with the adapted instruments. Technical and equipment-based constraints of bronchoscopy have become significantly easier. Many good references mentioned here are worth reading and must be used. Some technical aspects enhanced by our experience will be further discussed.
A. FIBER-OPTIC BRONCHOSCOPY EXAMINATION It all starts by the examination of the larynx, which is natural and easy with the fiber-optic bronchoscope; it is important for the pulmonologist to know the anatomy as well as the examination of the upper airways, as this could be very useful for the etiological diagnosis of certain pathologies (e.g., cough-induced gastroesophageal reflux). However, an ENT specialist may be referenced for the specificities of this anatomic area, and it will not be discussed here.
Normal and Pathological Bronchial Semiology DOI: https://doi.org/10.1016/B978-0-12-815795-4.00001-2
3
© 2019 Elsevier Inc. All rights reserved.
4
1. FIBER-OPTIC BRONCHOSCOPY
Endobronchial examination, along with the laryngo tracheo bronchial axis, is influenced by the practical conditions in which it is performed. General anesthesia is nowadays more often proposed, as it provides high comfort to both the patient and the operator; however, some information may be missing, for example, the upper respiratory tract, cough reflex, and trachea bronchial dynamics. Yet a lot of diagnostic fiberoptic bronchoscopies are still being conducted under local anesthesia. Sedative premedication 30 60 minutes before endoscopy is rarely useful, except for certain very anxious patients; in this case, it is better to propose the exam under mild sedation anesthesia with nitrous oxide gas mixtures, or strong sedation with midazolam or propofol, with no need for monitoring by anesthetist. Saliva aspiration during endoscopies induces cough reflex, it follows the endoscope and descends in the airways, Atropine may sometimes be used as premedication to decrease salivation. Hypnosis has been recently described in literature; its use is interesting, but requires the presence of hypnotherapist and therefore might not be adapted for fiber-optic endoscopies. Semi-seated position facing the operator is the most commonly used patient position in fiber-optic bronchoscopies performed under local anesthesia. This position makes it easier to provide explanations and reassurance during the examination, but this position does not work if the specialist or the patient does not feel comfortable. Flexible bronchoscopy is most often administered through the nose, which is the most permeable, and willingly if possible through the nostril on the opposite side from where the specialist is standing as the patient has tendency to tilt his head to the opposite side of the nasal orifice through which the bronchoscope is introduced. In case of small nasal passages, painful introduction, bleeding, or deformation due to old trauma or tumor obstruction of the nasopharynx, passage through the oral cavity using an endoscopic protector or mouth opener, despite salivation, will be more significant. Dorsal decubitus position is indispensable in endoscopy under local anesthesia; this position favors fluid accumulation in the dependent parts of the airways. Most specialists prefer the semi-seated position as it favors the effect of the local anesthesia in the divisions of the basal segments. In all cases, the upper lobes are re-anesthetized once the bronchoscope is introduced into the bronchus. Local anesthesia is deemed perfect when lidocaine installation no longer causes a cough and sound of bronchial crepitant paced by ventilatory movements.
NORMAL AND PATHOLOGICAL BRONCHIAL SEMIOLOGY
B. LOCAL ANESTHESIA
5
The optical quality of equipment produced nowadays is excellent; even small flexible bronchoscope provides better image quality than those used in the early 1970s. Colors rendered are not exactly those obtained with naked eye. Power source and contrast settings of video bronchoscopies make the interpretation of colors sensitive. However, color and appearance differences among various levels of the respiratory system to be noted and retained. During the examination, we need to take into account any potential minor traumatic injury of the mucous membranes caused by the bronchoscope during cough and suction. Every element in particular is important because it could often be a source of error; when the image viewed is not perfectly axial, the perspectives and architectural aspects will be misleading, for instance; appearance of the oval image must not be interpreted as narrowing if the bronchoscope and its lens are not within the axis. Finally, fiber-optic bronchoscopy is used mostly for sampling and diagnostic purposes, whereas rigid bronchoscopy is mainly used as a therapeutic tool. Fiber-optic bronchoscopy is used concomitantly with rigid bronchoscopy to explore the distal bronchi and the nonaxial divisions. However, interventional rigid bronchoscopy should be performed only in units where, institutionally, operators master the practice of flexible and rigid bronchoscopy.
B. LOCAL ANESTHESIA Imaging evaluation will be performed before bronchoscopy. Hemostasis laboratory tests are not systematic in the absence of pathological history or bleeding risk, which is properly checked during anamnesis; they must be adapted to the procedure scheduled. Laboratory evaluation does not preclude follow-up in case of complications. Digital monitoring of SpO2 and heart rate is important. Bronchoscopy room must be equipped for emergency care in case of respiratory distress, and the examination chair reclines and even changes into a bed during an emergency. Many articles describe different procedures of local anesthesia and it will not be developed here the best of them. Lidocaine is the most widely used local anesthesia. Lidocaine allergies are extremely rare and such an occurrence requires prior allergy investigation. Each institution and each endoscopist develop their own methodology when it comes to local anesthesia. After a few ground rules, the result is the only one that counts, and this result is evaluated, on one hand, by the comments of the patients who were examined by our colleagues, and, on the other hand, by the resistance of the patients to
NORMAL AND PATHOLOGICAL BRONCHIAL SEMIOLOGY
6
1. FIBER-OPTIC BRONCHOSCOPY
whom a second bronchoscopy would be suggested. Adequate communication and good explanations before the examination, attentive staff who reassure the patient, and a team focused exclusively on the procedure contributes to the best outcome, when vasovagal syncope is identified as the first unexpected event. The amount of lidocaine administered, recommended by the good practices of 2007, is a limited dose of 9 mg/kg of lidocaine for an adult weighing 70 kg, but one must take into account the concentration of the product, the way it is administered, the duration of its deposition time, the amount spat and swollen, hepatic functions, age and weight of the patient. Lidocaine absorbed in the gastrointestinal (GI) tract is metabolized very fast in the liver, while absorption by the pharyngolaryngeal and respiratory mucous membranes may greatly raise its serum concentration. Intralipid is proposed as an antidote in case of complication due to lidocaine; however, this requires venous access and vital care prevails over the initiation of this injection. Lidocaine is rarely toxic in local anesthesia. It most often occurs within 30 60 minutes from the end of the examination; the state of psychomotor agitation is one of the least known aspects of toxicity. The risk of toxicity justifies keeping the patients in the on-call room after the procedure. Neurological and cardiac toxicities are the most common. It is essential to be able to distinguish them from transient ischemic attacks. Although pneumothorax is usually suspected in case of transbronchial lung biopsies, air embolism is extremely rare, but it should also be considered. Fever spike and shivers may potentially occur in 5% of endoscopies, 8 12 hours after the procedure, caused by various rhino-sinusal and pharyngeal fluids and related pyrogen molecules that penetrate the bronchi up to the parenchyma, along with the bronchoscope. Paracetamol may prevent this transient fever. Patients need to be warned. However, prolonged fever is not normal and requires further investigation. In all cases, complete and bilateral exploration of the bronchial tree to check the permeability of the bronchi and exclude a contralateral pathology.
C. SAMPLES COLLECTION Bronchial aspiration of secretions is usually contaminated by saliva, upper airway and GI secretions, and anesthesia fluid. We will try to limit these contaminating factors as much as possible before sending an aspiration sample to the bacteriology virology mycology examination. Brushing of lesions suspected to be tumors is no longer used because it is poor in material.
NORMAL AND PATHOLOGICAL BRONCHIAL SEMIOLOGY
C. SAMPLES COLLECTION
7
Forceps biopsies have the highest diagnosis. Forceps manipulation requires training; it must be first introduced through the working channel and seen in the field of vision of fiber-optic bronchoscope before asking the assistant to open it to protect the working channel. The extremity of the forceps remains close to the extremity of the bronchoscope, and the combined movements of the spreader and the bronchoscope that bring the forceps to the area to be sampled; another technique is to stand away from the lesion and advance the forceps toward the lesion. After closing the forceps on the lesion, the traction effort causes a tactile sensation that we must estimate and we should account for. This traction of the forceps closed on the lesion may be accompanied by a small but powerful lateral movement of the bronchoscope spreader to increase the size of the biopsy. Several biopsies, five for the majority of authors, are recommended for one lesion. The first biopsy is a good predictor of the local risk of bleeding. Local adrenaline injection before biopsies can reduce the risk of bleeding. Transbronchial biopsies (TBLB) collect samples from the lung parenchyma; forceps is pushed progressively and gently toward the distal section into a bronchus whose lumen is aligned on the bronchoscope until resistance. Next, the forceps are retracted between 10 and 20 mm. After opening the forceps, they will be firmly pushed opened and then closed. Gentle traction will then be applied; if too much resistance maneuver should be stopped, loosen the forceps and then retract and restart. Too strong traction will pose a bleeding risk if it is not perfectly distal in the subpleural area. The distance between the lumen of the proximal bronchus and the distal parenchyma is quite variable, according to the pulmonary segment. It is long for the posterolateral bronchus of the lower lobe or the middle lobe divisions and very short for the anterobasal bronchus of the lower lobe. A fast or strong insertion of the forceps in the subpleural area for a TBLB may be very painful, and biopsies should not be done at the painful site. Bronchoalveolar lavage is performed to examin distal cellularity of lung parenchymal compartment and any potential infectious agents. Procedures vary from one institution to another; in all cases, one bronchus is chosen where the fiber-optic endoscope is wedged and whose lumen is viewed perfectly in front of the device. After fluid injection, slow aspiration, often the first return, deemed a proximal bronchial lavage, is not kept. The injected volume varies according to the pathology; it will be low in patients with respiratory failure, and it is recommended to always perform lavage under nasal oxygen therapy and oximetry.
NORMAL AND PATHOLOGICAL BRONCHIAL SEMIOLOGY
8
1. FIBER-OPTIC BRONCHOSCOPY
Selective cytohistological distal sample collections oriented toward a focal pathology will be best performed under an image intensifier. However, certain semi-proximal localized opacities, located just beyond the exploration field of the fiber-optic bronchoscopy and well tracked by imaging in the presence of the bronchus sign leading to opacity, may be performed by catheter-guided aspiration biopsy and by carefully guided biopsies without strong traction. Although it is useful, aspiration biopsies using a small flexible catheter for lesions with a diameter more than 2 cm are not used nowadays. It is a simple, rapid, less-invasive, and efficient diagnostic tool that may avoid CT-guided biopsy. Under these special circumstances, an ultrafine bronchoscope used by pediatric pulmonologists, anesthetists, and surgeons may gain a few orders of bronchial division, for divisions globally remaining in the segmental axis. They may make it possible to view lesions on which a careful biopsy will be subsequently performed by changing the endoscope. Today, electronavigation and mini-probe ultrasound make it possible to perform biopsies from distal lesions under better control.
NORMAL AND PATHOLOGICAL BRONCHIAL SEMIOLOGY
1 Fiber-Optic Bronchoscopy Adrian Crutu, Amir Hanna and Pierre Baldeyrou Interventional Bronchoscopy Unit, Division of Thoracic Surgery and Lung Transplantation, Marie Lannelongue Hospital, Paris, France
The complementary information collected through bronchoscopy, in addition to the physical and radiological examination, is very important that it has become an essential tool in the diagnosis and evaluation of the majority of bronchopulmonary pathologies. The role of bronchoscopy has and will continue to increase over the coming years, but semiology is the same, whether we use flexible or rigid bronchoscope. An optimal semiological analysis will lead to the most appropriate therapeutic intervention with the adapted instruments. Technical and equipment-based constraints of bronchoscopy have become significantly easier. Many good references mentioned here are worth reading and must be used. Some technical aspects enhanced by our experience will be further discussed.
A. FIBER-OPTIC BRONCHOSCOPY EXAMINATION It all starts by the examination of the larynx, which is natural and easy with the fiber-optic bronchoscope; it is important for the pulmonologist to know the anatomy as well as the examination of the upper airways, as this could be very useful for the etiological diagnosis of certain pathologies (e.g., cough-induced gastroesophageal reflux). However, an ENT specialist may be referenced for the specificities of this anatomic area, and it will not be discussed here.
Normal and Pathological Bronchial Semiology DOI: https://doi.org/10.1016/B978-0-12-815795-4.00001-2
3
© 2019 Elsevier Inc. All rights reserved.
4
1. FIBER-OPTIC BRONCHOSCOPY
Endobronchial examination, along with the laryngo tracheo bronchial axis, is influenced by the practical conditions in which it is performed. General anesthesia is nowadays more often proposed, as it provides high comfort to both the patient and the operator; however, some information may be missing, for example, the upper respiratory tract, cough reflex, and trachea bronchial dynamics. Yet a lot of diagnostic fiberoptic bronchoscopies are still being conducted under local anesthesia. Sedative premedication 30 60 minutes before endoscopy is rarely useful, except for certain very anxious patients; in this case, it is better to propose the exam under mild sedation anesthesia with nitrous oxide gas mixtures, or strong sedation with midazolam or propofol, with no need for monitoring by anesthetist. Saliva aspiration during endoscopies induces cough reflex, it follows the endoscope and descends in the airways, Atropine may sometimes be used as premedication to decrease salivation. Hypnosis has been recently described in literature; its use is interesting, but requires the presence of hypnotherapist and therefore might not be adapted for fiber-optic endoscopies. Semi-seated position facing the operator is the most commonly used patient position in fiber-optic bronchoscopies performed under local anesthesia. This position makes it easier to provide explanations and reassurance during the examination, but this position does not work if the specialist or the patient does not feel comfortable. Flexible bronchoscopy is most often administered through the nose, which is the most permeable, and willingly if possible through the nostril on the opposite side from where the specialist is standing as the patient has tendency to tilt his head to the opposite side of the nasal orifice through which the bronchoscope is introduced. In case of small nasal passages, painful introduction, bleeding, or deformation due to old trauma or tumor obstruction of the nasopharynx, passage through the oral cavity using an endoscopic protector or mouth opener, despite salivation, will be more significant. Dorsal decubitus position is indispensable in endoscopy under local anesthesia; this position favors fluid accumulation in the dependent parts of the airways. Most specialists prefer the semi-seated position as it favors the effect of the local anesthesia in the divisions of the basal segments. In all cases, the upper lobes are re-anesthetized once the bronchoscope is introduced into the bronchus. Local anesthesia is deemed perfect when lidocaine installation no longer causes a cough and sound of bronchial crepitant paced by ventilatory movements.
NORMAL AND PATHOLOGICAL BRONCHIAL SEMIOLOGY
B. LOCAL ANESTHESIA
5
The optical quality of equipment produced nowadays is excellent; even small flexible bronchoscope provides better image quality than those used in the early 1970s. Colors rendered are not exactly those obtained with naked eye. Power source and contrast settings of video bronchoscopies make the interpretation of colors sensitive. However, color and appearance differences among various levels of the respiratory system to be noted and retained. During the examination, we need to take into account any potential minor traumatic injury of the mucous membranes caused by the bronchoscope during cough and suction. Every element in particular is important because it could often be a source of error; when the image viewed is not perfectly axial, the perspectives and architectural aspects will be misleading, for instance; appearance of the oval image must not be interpreted as narrowing if the bronchoscope and its lens are not within the axis. Finally, fiber-optic bronchoscopy is used mostly for sampling and diagnostic purposes, whereas rigid bronchoscopy is mainly used as a therapeutic tool. Fiber-optic bronchoscopy is used concomitantly with rigid bronchoscopy to explore the distal bronchi and the nonaxial divisions. However, interventional rigid bronchoscopy should be performed only in units where, institutionally, operators master the practice of flexible and rigid bronchoscopy.
B. LOCAL ANESTHESIA Imaging evaluation will be performed before bronchoscopy. Hemostasis laboratory tests are not systematic in the absence of pathological history or bleeding risk, which is properly checked during anamnesis; they must be adapted to the procedure scheduled. Laboratory evaluation does not preclude follow-up in case of complications. Digital monitoring of SpO2 and heart rate is important. Bronchoscopy room must be equipped for emergency care in case of respiratory distress, and the examination chair reclines and even changes into a bed during an emergency. Many articles describe different procedures of local anesthesia and it will not be developed here the best of them. Lidocaine is the most widely used local anesthesia. Lidocaine allergies are extremely rare and such an occurrence requires prior allergy investigation. Each institution and each endoscopist develop their own methodology when it comes to local anesthesia. After a few ground rules, the result is the only one that counts, and this result is evaluated, on one hand, by the comments of the patients who were examined by our colleagues, and, on the other hand, by the resistance of the patients to
NORMAL AND PATHOLOGICAL BRONCHIAL SEMIOLOGY
6
1. FIBER-OPTIC BRONCHOSCOPY
whom a second bronchoscopy would be suggested. Adequate communication and good explanations before the examination, attentive staff who reassure the patient, and a team focused exclusively on the procedure contributes to the best outcome, when vasovagal syncope is identified as the first unexpected event. The amount of lidocaine administered, recommended by the good practices of 2007, is a limited dose of 9 mg/kg of lidocaine for an adult weighing 70 kg, but one must take into account the concentration of the product, the way it is administered, the duration of its deposition time, the amount spat and swollen, hepatic functions, age and weight of the patient. Lidocaine absorbed in the gastrointestinal (GI) tract is metabolized very fast in the liver, while absorption by the pharyngolaryngeal and respiratory mucous membranes may greatly raise its serum concentration. Intralipid is proposed as an antidote in case of complication due to lidocaine; however, this requires venous access and vital care prevails over the initiation of this injection. Lidocaine is rarely toxic in local anesthesia. It most often occurs within 30 60 minutes from the end of the examination; the state of psychomotor agitation is one of the least known aspects of toxicity. The risk of toxicity justifies keeping the patients in the on-call room after the procedure. Neurological and cardiac toxicities are the most common. It is essential to be able to distinguish them from transient ischemic attacks. Although pneumothorax is usually suspected in case of transbronchial lung biopsies, air embolism is extremely rare, but it should also be considered. Fever spike and shivers may potentially occur in 5% of endoscopies, 8 12 hours after the procedure, caused by various rhino-sinusal and pharyngeal fluids and related pyrogen molecules that penetrate the bronchi up to the parenchyma, along with the bronchoscope. Paracetamol may prevent this transient fever. Patients need to be warned. However, prolonged fever is not normal and requires further investigation. In all cases, complete and bilateral exploration of the bronchial tree to check the permeability of the bronchi and exclude a contralateral pathology.
C. SAMPLES COLLECTION Bronchial aspiration of secretions is usually contaminated by saliva, upper airway and GI secretions, and anesthesia fluid. We will try to limit these contaminating factors as much as possible before sending an aspiration sample to the bacteriology virology mycology examination. Brushing of lesions suspected to be tumors is no longer used because it is poor in material.
NORMAL AND PATHOLOGICAL BRONCHIAL SEMIOLOGY
C. SAMPLES COLLECTION
7
Forceps biopsies have the highest diagnosis. Forceps manipulation requires training; it must be first introduced through the working channel and seen in the field of vision of fiber-optic bronchoscope before asking the assistant to open it to protect the working channel. The extremity of the forceps remains close to the extremity of the bronchoscope, and the combined movements of the spreader and the bronchoscope that bring the forceps to the area to be sampled; another technique is to stand away from the lesion and advance the forceps toward the lesion. After closing the forceps on the lesion, the traction effort causes a tactile sensation that we must estimate and we should account for. This traction of the forceps closed on the lesion may be accompanied by a small but powerful lateral movement of the bronchoscope spreader to increase the size of the biopsy. Several biopsies, five for the majority of authors, are recommended for one lesion. The first biopsy is a good predictor of the local risk of bleeding. Local adrenaline injection before biopsies can reduce the risk of bleeding. Transbronchial biopsies (TBLB) collect samples from the lung parenchyma; forceps is pushed progressively and gently toward the distal section into a bronchus whose lumen is aligned on the bronchoscope until resistance. Next, the forceps are retracted between 10 and 20 mm. After opening the forceps, they will be firmly pushed opened and then closed. Gentle traction will then be applied; if too much resistance maneuver should be stopped, loosen the forceps and then retract and restart. Too strong traction will pose a bleeding risk if it is not perfectly distal in the subpleural area. The distance between the lumen of the proximal bronchus and the distal parenchyma is quite variable, according to the pulmonary segment. It is long for the posterolateral bronchus of the lower lobe or the middle lobe divisions and very short for the anterobasal bronchus of the lower lobe. A fast or strong insertion of the forceps in the subpleural area for a TBLB may be very painful, and biopsies should not be done at the painful site. Bronchoalveolar lavage is performed to examin distal cellularity of lung parenchymal compartment and any potential infectious agents. Procedures vary from one institution to another; in all cases, one bronchus is chosen where the fiber-optic endoscope is wedged and whose lumen is viewed perfectly in front of the device. After fluid injection, slow aspiration, often the first return, deemed a proximal bronchial lavage, is not kept. The injected volume varies according to the pathology; it will be low in patients with respiratory failure, and it is recommended to always perform lavage under nasal oxygen therapy and oximetry.
NORMAL AND PATHOLOGICAL BRONCHIAL SEMIOLOGY
8
1. FIBER-OPTIC BRONCHOSCOPY
Selective cytohistological distal sample collections oriented toward a focal pathology will be best performed under an image intensifier. However, certain semi-proximal localized opacities, located just beyond the exploration field of the fiber-optic bronchoscopy and well tracked by imaging in the presence of the bronchus sign leading to opacity, may be performed by catheter-guided aspiration biopsy and by carefully guided biopsies without strong traction. Although it is useful, aspiration biopsies using a small flexible catheter for lesions with a diameter more than 2 cm are not used nowadays. It is a simple, rapid, less-invasive, and efficient diagnostic tool that may avoid CT-guided biopsy. Under these special circumstances, an ultrafine bronchoscope used by pediatric pulmonologists, anesthetists, and surgeons may gain a few orders of bronchial division, for divisions globally remaining in the segmental axis. They may make it possible to view lesions on which a careful biopsy will be subsequently performed by changing the endoscope. Today, electronavigation and mini-probe ultrasound make it possible to perform biopsies from distal lesions under better control.
NORMAL AND PATHOLOGICAL BRONCHIAL SEMIOLOGY