TABLE 116.2 Causes of Alveolar Hemorrhage |
Physical Examination
The physical examination may provide clues to the diagnosis of massive hemoptysis. A saddle nose deformity and/or septal perforation suggest Wegener granulomatosis. Stridor or unilateral wheezing indicates a possible laryngeal tumor, tracheobronchial tumor, or airway foreign body. Pulmonary embolism should be considered in patients with tachypnea, a pleural friction rub, and lower extremity phlebitis. Diffuse rales on examination raises the possibility of diffuse alveolar hemorrhage, diffuse parenchymal lung disease, or cardiac disease as the cause of the hemoptysis. The presence of telangiectasias of the skin or mucous membranes suggests hereditary hemorrhagic telangiectasia or a connective tissue disease as the cause. Ecchymoses or petechiae suggest a hematologic abnormality or coagulopathy. Clubbing of the fingers may be a sign of a lung carcinoma, bronchiectasis, and cystic fibrosis. The finding of pulsation of the tracheostomy tube is of concern for the development of a tracheoinnominate fistula.
Laboratory Studies
Laboratory studies, including a complete blood count (CBC), coagulation studies, urinalysis, and chest radiograph, should be obtained in all patients. The CBC may suggest an infectious process or hematologic disorder as the cause of hemoptysis and indicate the need for blood transfusion. Coagulation studies may provide evidence for a hematologic disorder as the cause for the hemoptysis, or may identify a coagulopathy that is causing or contributing to the bleeding from another disease. Hematuria may be noted on urinalysis, which suggests the diagnosis of Goodpasture syndrome, Wegener granulomatosis, or another systemic vasculitis.
Chest Radiograph
The chest radiograph is an important study to identify the cause and side of bleeding. The chest radiograph may demonstrate abnormalities such as lung masses, cavitary lesions, atelectasis, focal infiltrates, and diffuse infiltrate. Single or multiple pulmonary cavities suggest neoplasm, tuberculosis, fungal disease, lung abscess, septic pulmonary emboli, parasitic infection, or Wegener granulomatosis as the cause for hemoptysis. The presence of a mass within a cavitary lesion indicates a possible mycetoma (aspergilloma). The appearance of a new air–fluid level in a cavity or infiltrate around a cavity is suggestive of the site of bleeding. A solitary pulmonary nodule that has vessels going toward the nodule may be an arteriovenous malformation. Diffuse pulmonary infiltrates suggest diffuse alveolar hemorrhage (Table 116.2), bleeding from coagulopathy, lung contusions from blunt chest trauma, hemorrhage with multiple areas of aspiration, or pulmonary edema with a cardiac cause for hemoptysis. Chest radiographs may be normal or nonlocalizing in 20% to 45% of patients (25,26). Therefore, in patients presenting with hemoptysis, a negative CXR warrants other diagnostic studies.
Computed Tomography
Computed tomography (CT) represents a noninvasive and highly useful imaging tool in the clinical context of hemoptysis, allowing a comprehensive evaluation of the lung parenchyma, airways, and thoracic vessels by using contrast material. Multidetector CT (MDCT) may identify the bleeding site in 63% to 100% of patients with hemoptysis (27); the role of CT in the management of massive hemoptysis is however somewhat controversial. CT may demonstrate abnormalities that are not visible on the chest radiograph. It is helpful in the diagnosis of bronchiectasis (28), although abnormalities from bronchiectasis can usually be appreciated on the chest radiograph. CT with contrast may detect pulmonary emboli, thoracic aneurysms, or arteriovenous malformations. CT scans may also demonstrate cavitation with a surrounding infiltrate, the halo sign, which suggests a necrotizing infection such as aspergillosis or mucormycosis (29,30). Some studies have noted that CT scanning before bronchoscopy may increase the yield of bronchoscopy (31). In one retrospective study of 80 patients with large or massive hemoptysis, chest CT was superior to chest radiograph or bronchoscopy in determining the cause of bleeding, and was similar to bronchoscopy in successfully localizing the site of bleeding (32). CT is useful to create a detailed and accurate map of the thoracic vasculature that may guide further treatment, depicting the number and origin of bronchial arteries and the coexistence of an additional nonbronchial arterial supply. CT can thus assist in choosing ectopic vessels amenable to embolization, preventing recurrence after initial successful embolization, reducing angiography procedure time, fluoroscopy radiation dose, contrast load, and decreasing iatrogenic complications (12). Some authors have argued that transport of the potentially unstable patient with massive hemoptysis may not be judicious, however; thus, the patient should be adequately stabilized prior to obtaining a chest CT.
Angiography
Angiography can determine the site of bleeding in 90% to 95% of cases. However, in one case series, routine use of diagnostic angiography provided a diagnosis not identified on bronchoscopy in only 4% of patients (33). Angiography can be helpful in detecting a pseudoaneurysm that has formed after healing of a pulmonary artery tear from pulmonary artery catheterization (34). As previously noted, the bronchial arteries and other collateral systemic arteries account for the source of bleeding in most cases with massive hemoptysis. Pulmonary angiography is usually performed only when there is suspicion for pulmonary aneurysms, arteriovenous malformations, and pulmonary embolism. Technetium labeled red blood cell or colloid studies rarely provided any information that is not obtained by bronchoscopy and chest CT. The use and timing of bronchoscopy will be discussed in a subsequent section.
Bronchoscopy
Bronchoscopy, performed with either a rigid or flexible endoscope, is helpful for identifying active bleeding and for checking the airways in patients with massive hemoptysis. The capability and success of bronchoscopy in localizing the bleeding site may vary according to the rate and severity of the hemorrhage. Hirshberg et al. (4) found that bronchoscopy was more effective in finding the bleeding site in patients with moderate to severe hemoptysis (64% and 67%) than in those with mild hemoptysis (49%). Bronchoscopy has an overall lower sensitivity than MDCT in detecting the underlying causes of bleeding (25,27,31). Nevertheless, bronchoscopy yields additional information on endobronchial lesions and allows samples for tissue diagnosis and microbial cultures.
Other Studies
Depending on the suspected causes of massive hemoptysis, additional studies may be indicated. Echocardiography may be performed if a cardiac cause is considered. If diffuse alveolar hemorrhage syndromes are suspected, laboratory testing, including antiglomerular basement membrane antibody, antineutrophilic cytoplasmic antibody, antinuclear antibody, rheumatoid factor, complement levels, cryoglobulins, and antiphospholipid antibodies, should be performed, depending on the causes that are being considered. Transbronchial lung biopsy, open lung biopsy, or kidney biopsy may be indicated in some cases of alveolar hemorrhage to establish a diagnosis.
MANAGEMENT OF MASSIVE HEMOPTYSIS
Airway Protection and Stabilization
Once the diagnosis of massive hemoptysis is established, the initial priorities are to protect the airway and stabilize the patient. In general, the patient with massive hemoptysis should be monitored in the ICU setting, even if intubation and mechanical ventilation are not required. Large bore IV access should be established and supplemental oxygen provided. Blood should be drawn for a CBC, arterial blood gas analysis, coagulation studies, electrolytes, renal function tests, and liver function tests. The patient should be type and cross-matched for blood, with 4 to 6 units of packed red blood cells always available. Correction of thrombocytopenia and coagulopathy, if present, with appropriate blood products should be considered. Attempts to lateralize the site of bleeding should be made in anticipation of steps to prevent aspiration into the nonbleeding lung; the patient may be positioned in a lateral decubitus position with the bleeding lung down.
Airway patency must be ensured in patients with massive hemoptysis, as deaths from this process are predominantly due to asphyxiation. Most patients with ongoing massive hemoptysis will require intubation and mechanical ventilation, although select patients who are not hypoxemic and are able to keep the airway clear on their own may not require intubation. Although intubation generally preserves oxygenation and facilitates blood removal from the lower respiratory tract, the ET can become obstructed by blood clots, leading to the inability to oxygenate and ventilate the patient. The largest possible ET should be inserted to allow the use of bronchoscopes with a 2.8- to 3.0-mm working channel for more effective suctioning and to allow for better ventilation with the bronchoscope in the airway for prolonged periods of time. In severe cases, the mainstem bronchus of the nonbleeding lung can be selectively intubated under bronchoscopic guidance to preserve oxygenation and ventilation from the normal lung.
Some authors have recommended the use of a double-lumen ET to isolate the normal lung and permit selective intubation. Although double-lumen ETs have been used successfully in the airway management of massive hemoptysis, there are several potential pitfalls. First, placement of a double-lumen ET is difficult for less experienced operators, particularly with a large amount of blood in the larynx and oropharynx. Second, the individual lumens of the ET are significantly smaller than a standard ET and are at significant risk of being occluded by blood and blood clots. Last, positioning of the double-lumen ET and subsequent bronchoscopic suctioning of the distal airways require a small pediatric bronchoscope with working channels of 1.2 to 1.4 mm. Adequate suctioning of large amounts of blood and blood clots through such bronchoscopes is extremely problematic. In one series of 62 patients with massive hemoptysis, death occurred in four of seven patients managed with a double-lumen ET due to loss of tube positioning and aspiration (35). In general, we do not recommend the use of double-lumen ETs for airway management in massive hemoptysis. As an alternative to selective mainstem bronchial intubation or intubation with a double-lumen ET, an ET that incorporates a bronchial blocker, such as the Univent tube, may be used.
Localization of Source and Cause of Hemoptysis
Once the patient is stabilized and airway patency is achieved, the source of bleeding should be localized as precisely as possible, and the cause of bleeding determined. Identification of the cause and location of the bleeding potentially allows for more specific therapy. Methods of localization include patient history, physical examination, chest radiograph, chest CT, bronchoscopy, and angiography. In one study of 105 patients with hemoptysis, patients themselves were able to localize the side of bleeding in 10% of cases, but with an accuracy of 70% when able to do so (36); localization by a physical examination performed by a physician was possible in 43% of patients. Chest radiographs were able to localize bleeding in 60% of cases. Bronchoscopy was accurate in localizing the source of bleeding in 86% of patients. In another study, 9 of 24 patients were able to accurately localize the side of their bleeding (37). Chest radiographs should be routinely obtained to help localize the source of bleeding and determine the cause. As discussed earlier, chest CT may provide additional information beyond the chest radiograph, and may be more accurate in localizing the bleeding and determining the cause, although concerns about transporting a potentially unstable patient out of the ICU exist (7,38). Bronchoscopy and angiography remain the modalities for localizing the source of hemoptysis and offer potential therapeutic intervention.
Early—rather than delayed—bronchoscopy should be performed to increase the likelihood of localizing the source of bleeding. Bronchoscopy performed within 48 hours of bleeding onset successfully localized bleeding in 34% to 91% of patients, depending on the case series, as compared to successful localization in 11% to 52% of patients if delayed bronchoscopy was performed (39). Bronchoscopy performed within 12 to 24 hours may provide an even higher yield. Bedside flexible bronchoscopy should not be performed to establish a diagnosis of a tracheoarterial fistula such as a tracheoinnominate fistula (21,40).
Bronchoscopic Therapies to Control Hemoptysis
Rigid bronchoscopy is the most efficient means of clearing the airways from blood clots and secretions, ensuring effective tamponade of the bleeding airway and safe isolation of the nonaffected lung, thereby preventing asphyxia and preserving ventilation. However, it requires a trained bronchoscopist, who is not always readily available. A variety of maneuvers can be performed with the flexible bronchoscope to control bleeding.
Balloon Tamponade
Endobronchial tamponade via flexible bronchoscopy can prevent aspiration of blood into the contralateral lung and preserve gas exchange in patients with massive hemoptysis. Endobronchial tamponade can be achieved with a 4-Fr Fogarty balloon-tipped catheter. The catheter may be passed directly through the working channel of the bronchoscope, or the catheter can be grasped with biopsy forceps placed though the working channel of the bronchoscope prior to introduction into the airway of the bronchoscope and catheter. The catheter is held in place adjacent to the bronchoscope by the biopsy forceps, and both are then inserted as a unit into the airway. The catheter tip is inserted into the bleeding segmental orifice, and the balloon is inflated. If passed through the suction channel, the proximal end of the catheter is clamped with a hemostat, the hub cut off, and a straight pin inserted into the catheter channel proximal to the hemostat to maintain inflation of the balloon catheter. The clamp is removed, and the bronchoscope is carefully withdrawn (41–43). The catheter can safely remain in position between 15 minutes and 1 week, until hemostasis is ensured by surgical resection of the bleeding segment or bronchial artery embolization. It should be deflated for a few minutes three times a day, in order to preserve mucosal viability and to check for bleeding recurrence. Right heart balloon catheters have been used in a similar fashion (44). A modified technique for placement of a balloon catheter has been described using a guidewire for insertion. A 0.035-in soft-tipped guidewire is inserted through the working channel of the bronchoscope into the bleeding segment. The bronchoscope is withdrawn, leaving the guidewire in place. A balloon catheter is then inserted over the guidewire and placed under direct visualization after reintroduction of the bronchoscope (45). The use of endobronchial blockers developed for unilateral lung ventilation during surgery may hold promise for management of massive hemoptysis in tamponading bleeding and preventing contralateral aspiration of blood (46). The Arndt endobronchial blocker is placed through a standard ET and directly positioned with a pediatric bronchoscope. Suctioning and injection of medications can be performed through the lumen of the catheter after placement. The Cohen tip deflecting endobronchial blocker is also placed through a standard ET and directed into place with a self-contained steering mechanism under bronchoscopic visualization. At this time, there is limited published experience with these blockers in the setting of massive hemoptysis, although the author has successfully used them for this application.
Other Bronchoscopic Techniques
Additional bronchoscopic techniques may be useful as temporizing measures in patients with massive hemoptysis. Bronchoscopically administered topical therapies, such as iced sterile saline lavage or topical 1:10,000 or 1:20,000 epinephrine solution, may be helpful (47). Direct application of a solution of thrombin or a fibrinogen–thrombin combination solution has been used (48). The use of bronchoscopy-guided topical hemostatic tamponade therapy using oxidized regenerated cellulose mesh has recently been described (49). Endobronchial placement of a silicone spigot can prove adequate for temporary control of bleeding, allowing patients to stabilize before endovascular embolization (50). Successful tamponade and isolation of the bleeding site in patients with massive hemoptysis can be achieved by the placement of covered self-expanding airway stents blocking the orifice of the bleeding airway (51). Although anecdotal, the author has had success with topical application of a sodium bicarbonate solution.
For patients who have hemoptysis due to endobronchial lesions, particularly endobronchial tumors, hemostasis may be achieved with the use of neodymium:yttrium aluminum garnet (Nd:YAG) laser phototherapy, electrocautery, argon plasma coagulation (APC), or cryotherapy via the bronchoscope.
Angiography and Embolization
Angiography can identify the bleeding site in more than 90% of cases. As noted, the bronchial arteries are the most frequent source of bleeding in massive hemoptysis. In some cases, systemic vessels other than the bronchial arteries can be the source of bleeding (52). The pulmonary arteries may be the source for massive hemoptysis in 8% to 10% of cases (53). Visualization of extravasated dye from a vessel is relatively uncommon. Signs suggesting a particular vessel is the source of bleeding include vessel tortuosity, increased vessel diameter, and aneurysmal dilatation.
Bronchial artery embolization has been widely used to control massive hemoptysis, as a temporary measure to stabilize patients before surgical resection or medical treatment (antibiotics/antituberculous drugs) or as a definitive therapeutic approach in patients who refuse surgery, who are not considered as candidates for surgery (poor lung function, bilateral pulmonary disease, comorbidities), or patients in whom surgery is contraindicated. Bronchial artery embolization is considered the most effective nonsurgical modality for treatment of massive hemoptysis. The immediate success rates from bronchial artery embolization range from 51% to 100% (3,9,37,54–66). This wide range of success rates across multiple studies can be partially attributed to heterogeneity with regard to analysis of results with some series, including patients in whom bronchial artery cannot be canalized or that spinal artery was seen coming off the bronchial vessel preventing embolization in the final analysis (61). Embolization has been performed with Gelfoam, polyurethane particles, polyvinyl alcohol particles, and vascular coils. Sclerosing agents may cause subsequent lung necrosis and should be avoided. Recurrence of bleeding, although usually nonmassive, has been noted in 16% to 46% of patients (9,54). Recurrence of hemoptysis may be due to incomplete embolization of the bronchial vessels, recanalization of the embolized arteries, presence of nonbronchial systemic arteries, or development of collateral circulation in response to continuing pulmonary inflammation (60,67). Repeat embolization may be required in some patients (37,59,63,68). Complications include chest pain, fever, vessel perforation and intimal tears, and embolization of material to mesenteric and extremity arteries. The most serious complication is embolization of the anterior spinal artery, which may arise from the bronchial artery, with subsequent spinal artery infarction and paraparesis; the risk of this occurrence is less than 1%.
Rupture of the Pulmonary Artery
The pulmonary artery may potentially be ruptured from right heart catheterization. This complication should be suspected in patients who develop hemoptysis with a pulmonary artery catheter in place. Balloon tamponade and contralateral selective intubation should be performed (69). The catheter should be withdrawn 5 cm with the balloon deflated, and the balloon then reinflated with 2 mL of air and allowed to float back into the ruptured vessel to occlude it. Patients who stop bleeding should undergo angiographic evaluation to localize the tear and identify the formation of a pseudoaneurysm (34,70). If a pseudoaneurysm is identified, embolization of the affected vessel should be considered to prevent subsequent hemorrhage.
Surgery
Emergency surgery for control of massive hemoptysis is performed less often due to the advent of bronchial artery embolization. Mortality rates for surgical management of massive hemoptysis range from 1% to 50% (3,71–76). Surgical resection of the source of bleeding offers definitive treatment as long as the lesion can be completely resected and the patient is able to tolerate resectional surgery. It is often difficult to accurately determine if these patients will be able to tolerate surgery, as they are often too ill to undergo pulmonary function tests, or are intubated and thus unable to perform pulmonary function tests. Surgical resection may be considered in patients when bronchial artery embolization is unavailable, if bleeding continues despite embolization, or if the cause of the hemoptysis is unlikely to be controlled with embolization.
Surgery also remains the strategy of choice for the management of massive hemoptysis caused by diffuse and complex arteriovenous malformations, iatrogenic PA rupture, chest trauma, and mycetoma not responding to other therapeutic strategies, or associated with recurrent life-threatening hemoptysis as outlined above. Bronchovascular fistulae—with ensuing massive bleeding, is most often encountered following surgery, local infection, associated with vascular aneurysms and, less frequently, following lung transplantation surgery—are also managed by surgical repair once the patient is stabilized (1).
Diffuse Alveolar Hemorrhage
Patients with diffuse alveolar hemorrhage syndromes are not candidates for bronchial artery embolization or surgery; treatment for these groups of patients is pharmacologic. Corticosteroids are typically used and are effective for a wide range of the alveolar hemorrhage syndromes (77). Doses of 1 to 2 mg/kg/day of methylprednisolone have been most commonly used. For life-threatening alveolar hemorrhage, initial doses of 500 to 1,000 mg/day of methylprednisolone have been recommended. For Goodpasture disease, granulomatosis polyangiitis, and other vasculitides, adjunctive cytotoxic therapy or plasmapheresis may be considered.
PROGNOSIS
Factors associated with high mortality in patients with massive hemoptysis include a bleeding rate of at least 1,000 mL within a 24-hour period, aspiration of blood in the contralateral lung, massive bleeding requiring single lung ventilation, and bronchogenic carcinoma as an underlying etiology (3,6). Patients seem to fare better when tuberculosis, bronchitis, or bronchiectasis are responsible for the massive hemoptysis. Patients who experience recurrent bleeding following embolization for massive hemoptysis have significantly higher mortality (78). Overall mortality rates for massive hemoptysis range from 9% to 38% (58,61,79), with significant reduction in mortality in recent years since bronchial artery embolization is considered as first-line therapy.
INTERVENTIONAL BRONCHOSCOPY
Interventional bronchoscopy is a field that utilizes minimally invasive techniques for the management of a variety of tracheobronchial disorders. There are a number of circumstances for which interventional bronchoscopy has application in the ICU. The most common need for such procedures arises from central airway obstruction (CAO), both malignant and benign in etiology. Other potential situations that interventional bronchoscopy may be of benefit include management of hemoptysis and management of persistent airleaks.
Malignant Airway Obstruction
CAO from malignancy may arise from endoluminal tumor, submucosal tumor infiltration, extrinsic compression by a tumor mass, extrinsic compression by malignant mediastinal adenopathy, or a combination of these pathologies. Bronchogenic carcinoma is the most common cause of malignant airway obstruction. The exact prevalence of airway obstruction in patients with lung cancer is not clear although it has been estimated that 20% to 30% of patients will develop large airway obstruction (80). Patients with other malignancies may also develop endobronchial metastases. Cancers of the thyroid, colon, breast, kidney, and esophagus as well as melanoma have been most commonly noted to cause endobronchial metastases. As a result of the airway obstruction, patients may experience respiratory distress, hypoxemia, or frank respiratory failure requiring mechanical ventilation. Postobstructive pneumonia may also occur.
Benign Airway Obstruction
Patients may develop tracheal stenosis or tracheal webs following endotracheal intubation. The reported incidence ranges from 10% to 22%, although only 1% to 2% of patients are symptomatic or have severe stenosis (81). Most stenoses occur at the site of the ET cuff, thought to be due to decreased regional blood flow as a result of pressure of the cuff on the tracheal wall. A similar incidence has been reported following tracheostomy tube placement (82). While patients may develop stenoses or webs at the site of the tracheostomy tube cuff, tracheal stenosis following tracheostomy tube placement typically occurs around the tracheal stomal site. This is thought secondary to abnormal wound healing with excess granulation tissue formation around the tracheal stoma (81). In addition, patients may develop focal tracheomalacia at the level of the stoma secondary to cartilaginous damage (dynamic A-shaped tracheal stenosis) (83). Patients may also develop airway obstruction secondary to granulation tissue above the tracheostomy tube and at the tip of the tracheostomy tube. Finally, patients may also develop tracheal or bronchial stenosis as a consequence of systemic disease, such as granulomatous polyangiitis (Wegener granulomatosis), relapsing polychondritis, sarcoidosis, and tracheobronchial amyloidosis. In about 3% to 5% of cases of tracheal stenosis, there is no known inciting process for the development of the stenosis and such cases are labeled idiopathic (84).
Expiratory central airway collapse—comprises two separate entities: tracheobronchomalacia (TBM), characterized by weakness of the airway cartilages, and excessive dynamic airway collapse (EDAC)—which is defined as excessive bulging of the posterior membrane into the airway lumen during expiration without cartilage collapse—may produce significant airway obstruction (85). Focal tracheomalacia may result from prolonged intubation, tracheostomy tube placement, vascular abnormalities such as vascular rings, and space occupying lesions of the mediastinum such as a large thyroid goiter. Focal tracheomalacia and bronchomalacia can occur following radiation therapy; diffuse TBM can result from relapsing polychondritis, and EDAC is associated with COPD, asthma, and obesity.
History and Evaluation
Symptoms depend on the location and degree of airway narrowing as well as concurrent thoracic pathology. Dyspnea is the most common symptom. Dyspnea on exertion typically occurs when the tracheal diameter is reduced to 8 mm; stridor may be noted when the tracheal diameter decreases to 5 mm (86). Airway narrowing of this degree increases susceptibility to acute obstruction from mucus plugs or blood clots. This is thought to be the reason why 50% of these patients present with acute respiratory distress. CT may be used as the initial evaluation modality for tracheobronchial obstruction. MDCT with thin collimation (0.6–1.5 mm) over the entire chest during a single breath hold at full inspiration allows acquisition of volumetric high resolution data sets. Reconstruction of axial overlapped thin slices permits multiplanar reformations of high quality. CT is useful for diagnosing the nature of the obstruction, identifying the precise anatomical location, the characteristics of the lesion, and the extent of disease, including distal airway patency and local vascular anatomy (87,88). Multiplanar reformations in sagittal, coronal, or oblique planes eliminate the known limitation of axial images including detection of subtle airway stenoses, underestimation of the longitudinal extent of narrowing, inadequate evaluation of the airways oriented obliquely to the axial plane, and the difficulty in displaying complex three-dimensional anatomy of the airways. In addition, virtual bronchoscopy imaging can be performed using CT images constructed during postprocessing. Flexible bronchoscopy can be used as a diagnostic modality although ideally bronchoscopy, either flexible or rigid, is performed in conjunction with a bronchoscopic therapeutic intervention. Caution should be taken in performing bronchoscopy in high-grade tracheal or bilateral mainstem obstruction if an interventional pulmonologist/thoracic surgeon is not available as a diagnostic bronchoscopy may precipitate acute, complete airway occlusion.
Interventional Bronchoscopy Techniques
Various interventional bronchoscopy modalities are available to manage malignant or benign CAO. Mechanical debulking and dilatation may be performed with a rigid bronchoscope to relieve obstruction from endoluminal tumor as well as benign stenoses. Rigid bronchoscopy may also be used in conjunction with other ablative modalities, and has some advantages over interventions performed via flexible bronchoscopy including the ability to ventilate the patient through the rigid bronchoscope, use of larger suction catheters to manage blood in the airway, and use of larger forceps to remove tumor and debris.
A variety of ablative techniques are available for relieving obstruction from endoluminal tumor (Table 116.3). Laser, electrocautery, and APC utilize heat thermal energy for tissue destruction. Microdebriders have been used in conjunction with rigid bronchoscopy for mechanical debulking; these debriders are composed of a serrated blade rotating at 1,000 to 3,000 rpm attached to a hollow suction tube (89). These modalities, as well as mechanical debulking with the rigid bronchoscope, have the advantage of achieving immediate airway patency. Either silicone or self-expanding metal stents will often be placed to maintain airway patency once the airway is de-obstructed. Other techniques such as standard cryotherapy, brachytherapy, and photodynamic therapy have the disadvantages of not achieving immediate airway patency and thus would not be the procedures of choice for patients in the ICU with CAO. A modification of the method of cryotherapy, referred to as cryorecanalization, is able to achieve immediate airway patency, however (90).
TABLE 116.3 Comparison of Ablative Modalities | |||