Case Scenario: Perioperative Airway Management of a Patient with Tracheal Stenosis

Abstract

TRACHEAL stenosis is a rare but a life-threatening condition and is caused by congenital problems, postintubation injury, trauma, tracheal tumor, and compression of the trachea by tumor. Although accurate prevalence of this condition is unknown, an incidence of 4.9 cases per million per year is estimated for postintubation tracheal stenosis.1A stenosis commonly occurs at the cuff of the tube (intrathoracic trachea) or at the level of the tracheostomy stoma (extrathoracic trachea).Anesthesia of a patient with tracheal stenosis is challenging for anesthesiologists. Depending on the severity and location of the stenosis and the type of surgical procedure, there may be a variety of choices for perioperative airway management such as a facemask, laryngeal mask airway,2an tracheal intubation tube,3,4cardiopulmonary bypass,5and extracorporeal membrane oxygenation.6The American Society of Anesthesiologists practice guidelines for management of the difficult airway primarily focus airway problems caused at the extrathoracic airway and may not be helpful, particularly for managing patients with intrathoracic tracheal stenosis.7In this case scenario, we present a patient with severe intrathoracic tracheal stenosis, who required surgery for a lumbar fracture in the prone position. Various airway management strategies and the actual management used are discussed.A 38-yr-old obese man (height, 172 cm; weight, 95 kg; body mass index, 32 kg/m2) was scheduled to have a thoracolumbar laminectomy and fixation for a burst fracture of the first lumbar vertebra. Surgery was to be performed in the prone position. The operation duration and blood loss were preoperatively estimated to be 4 h and 500 ml. He had a history of prolonged intubation when he suffered a traumatic brain injury at 8 yr of age. He had epilepsy treated with phenobarbital but had no impairment of neurologic development and was cooperative. Despite undergoing tracheal resection and plasty for severe postintubation tracheal stenosis at 17 yr of age, he had relatively loud inspiratory and expiratory stridor while awake. Spirometry in the sitting position revealed reduced forced expiratory volume in the first second (FEV1= 1.95 l, 53%-predicted) and peak expiratory flow rates (PEF = 180 l/min, 30% predicted). Arterial blood gas analysis indicated mild impairment of oxygenation but normal ventilation (Fio2= 0.2, pH = 7.43, Pao2= 71 mmHg, Paco2= 33 mmHg). A flow-volume loop showed a typical upper airway obstruction pattern (fig. 1). Three-dimensional computed tomography (CT) of the trachea revealed severe intrathoracic tracheal stenosis more than 3 cm in length. In cross-section, the stenotic lesion was elliptical with a minor axis of 0.5 cm and a major axis of 1.5 cm (fig. 2). Despite the tracheal stenosis, he had no dyspnea during daily activities and was otherwise healthy. Nurses in the ward witnessed loud snoring and occasional apnea during sleep. Preoperative airway examination revealed Mallampati class 3, normal thyromental distance, and no limitation of neck or mandible movements. The orthopedic surgeons considered that neither conservative therapy nor surgery with regional anesthesia was appropriate because of his neurologic symptoms and the estimated operational duration and invasiveness of the surgery.Only the preoperative information with the figures described above was initially sent to both Drs. Asai and Cook. They were selected because of their previous reports of similar cases.3,4The following are their airway management plans for this patient.I follow an algorithm for anesthetic management of patients with tracheal stenosis based on its pathophysiology (fig. 3). Although the patient had relatively loud inspiratory and expiratory stridor and apnea during sleep, he had no dyspnea during daily activities. Therefore, I consider that spontaneous breathing or mechanical ventilation is likely to be possible through the stenosis with general anesthesia. Nevertheless, severe airway obstruction may occur during induction of general anesthesia, and thus the appropriate backup method will be required to prevent disaster.There are three possible methods for airway management of this case: (1) the use of a supraglottic airway alone, (2) the use of a supraglottic airway and a tube-exchange catheter, and (3) the use of a supraglottic airway, an endotracheal tube, and a tube-exchange catheter such as Cook Airway Exchange Catheter (Cook Medical, Bloomington, IN; 2.7 mm internal diameter [ID]). The choice of method would depend on both the risks of airway obstruction or dislodgement of the selected airway device and accessibility of the airway for reinsertion of the device.In this case, the airway might be managed with a supraglottic airway alone, but there are two major potential problems with this method: airway obstruction after induction of anesthesia and dislodgement of the supraglottic airway (particularly when the patient is turned to prone position from the supine position). One possible solution is to place the patient in the prone position and insert a supraglottic airway while the patient is still awake, and then induce anesthesia with increasing concentrations of sevoflurane while maintaining spontaneous breathing. Although the presence of the supraglottic airway would prevent airway obstruction above the vocal cords, worsening of the tracheal stenosis and hence severe airway obstruction may develop during inhalational induction with sevoflurane. In such a case, administration of sevoflurane should be terminated and the patient should be woken up. If inadvertent dislodgement of the airway device in the prone position is a risk, safety would be increased by prior insertion of a tube-exchange catheter, because this would enable both the maintenance of oxygenation until reinsertion of the supraglottic airway and the tracheal intubation through it.4,8Alternatively, a more conservative but a safer approach, which I consider the most appropriate in this case, is tracheal intubation with the two backup methods of the use of both a supraglottic airway and a tube-exchange catheter. In this case, the narrowest caliber of the trachea is 5 mm, and thus the largest size of an endotracheal tube, which can be passed through the stenosis, would be 4.0 mm ID, and ventilation may not be sufficient. Therefore, it would be necessary to insert a larger endotracheal tube with its tip proximal to the stenosis. Three-dimensional CT indicates that the stenosis is in the mid to lower trachea, and thus it would only be possible to insert the distal 3-4 cm of the endotracheal tube into the trachea, necessitating backup plans, in case of tube dislodgement. In such an event, either the supraglottic airway or the exchange catheter could then be used for maintaining oxygenation and reinserting the endotracheal tube. I would prepare for jet ventilation through the exchange catheter.After preoxygenation of the patient in the supine position, I would allow the patient to breathe increasing concentrations of sevoflurane in oxygen, and then assist ventilation manually via a facemask. After injection of a neuromuscular blocking agent, I would insert a Cook airway exchange catheter into the trachea under direct laryngoscopy, and then insert either the ProSeal Laryngeal Mask Airway ™ (PLMA ™; Laryngeal Mask Company, Henley-on-Thames, United Kingdom) #5 or i-gel (Intersugical Ltd., Wokingham, Berkshire, United Kingdom), another supraglottic airway, while the exchange catheter is placed outside the supraglottic airway. With the aid of a fiberoptic bronchoscope, I would pass a reinforced endotracheal tube through the supraglottic airway into the trachea so that the tip of the endotracheal tube is approximately 1-2 cm proximal to the stenosis. I would not inflate the endotracheal tube cuff, because it would be positioned at the glottis. Wrapping adhesive tape around the endotracheal tube at the connecter of the supraglottic airway would prevent both dislodgement of the endotracheal tube and gas leakage through the supraglottic airway. I would then adjust the position of the exchange catheter so that its tip is beyond the tracheal stenosis. After the patient is turned to the prone position, I would confirm (using a fiberscope) the appropriate positions of both endotracheal tube and exchange catheter. I would maintain the tidal volume as low as possible allowing hypercapnia to prevent excessive peak airway pressure. When possible, spontaneous breathing would be resumed. After surgery, I would remove the supraglottic airway once the patient has recovered from general anesthesia and is responsive to verbal commands, but would leave the tube exchange catheter in place, until it becomes certain that the patient can maintain a clear airway.This is a truly difficult patient. I would first reiterate to the surgeons that perioperative airway complications are a potential risk to the patient's life. The options of conservative treatment or transfer to a center with facility for combined tracheal reconstructive and trauma surgery must be explicitly considered.Assuming neither is possible I would premedicate the patient with a proton pump inhibitor 12 h before anesthesia. Two experienced anesthetists and an experienced anesthetic assistant would be required and briefed. I would start by placing a narrow gauge cricothyroid cannula specifically a 13-gauge Ravussin cannula (VBM Medizintechnik, Sulz, Germany) with local anesthesia and confirm its position by feeling expired gas, seeing gas exit through a bubble of saline and with capnography. If there was concern about the position of the Ravussin cannula, I would perform awake fiberoptic inspection to confirm its position before proceeding. Next, I would place a PLMA ™. If the patient was cooperative, I would do this during topical anesthesia. If he was not I would place it during general anesthesia. I would preoxygenate the patient fully with continuous positive airway pressure performed with at least 25 degrees head up position to increase lung volumes and maximize the apnea period before hypoxemia develops. I would administer a modest dose of opioid (e.g. , fentanyl 100 μg titrated in > 2-3 min) and propofol by target-controlled infusion. I would start with a low propofol effect site target (1-1.5 μg/ml) and increase this in steps of 0.5 μg/ml for every 1-3 min while maintaining spontaneous ventilation. At the point of eye closure, but before full anesthesia, I would assess ease of assisted ventilation. If ventilation was difficult or impossible, I would abandon this attempt and allow the patient to wake up. After confirmation of adequate mask ventilation, I would then paralyze with rocuronium, increase the depth of anesthesia, and insert a PLMA ™, using a bougie-guided technique.9,10After placement of the PLMA ™, I would then intubate the trachea through it. If the PLMA ™ was placed awake, I would induce anesthesia after PLMA ™ placement. For intubation, I would use a 4.2-mm fiberscope on which an Aintree Intubating Catheter (AIC; Cook Medical, Bloomington, IN) was mounted. After passage of the AIC, I would railroad a 6.5-mm ID intubating Laryngeal Mask Airway ™ (LMA ™) endotracheal tube over it. If the AIC passed easily, I that the intubating ™ endotracheal tube would If the AIC was I would pass a Cook airway exchange catheter through the AIC and railroad a ID tube over the airway exchange catheter. I would then confirm position of the endotracheal tube beyond the stenosis. If the AIC could not pass I would until was may be to its to and of and then wake up the patient. surgery, I would administer of to of the stenotic At the of surgery, I would exchange the endotracheal tube for a Cook airway exchange catheter and a PLMA ™. I would then assess ease of ventilation with the patient still I would then allow the patient to wake and remove the PLMA ™, but not the exchange catheter. If there was of trauma during the intubation or concern about at the of I would the patient to for h of ventilation, and to allow airway to history of tracheal surgery and stridor a tracheal at the stenotic allowing insertion of an endotracheal tube with mm that only mm ID the tracheal considered that positive pressure ventilation with such a diameter tube might be difficult in this obese patient during surgery in prone position. traumatic insertion and prolonged placement of a larger diameter tube were considered to be because of the potential for development of and of the trachea after tracheal Therefore, we not to intubate the trachea, but to use the PLMA ™ for positive pressure ventilation. The patient with this after we its potential and risks to of symptoms and body potential we performed , the of by or more the level per Although an than 5 of the was 3 this the of the continuous positive airway pressure was because this could maintain tracheal both for treatment of his snoring and in case of at the tracheal stenosis after The patient this treatment anesthesia was with administration of and and a PLMA ™ was by a was with sevoflurane and an of With ventilation during surgery inspiratory pressure cm positive pressure cm 8 inspiratory expiratory through the PLMA ™, we no of airway or limitation such as low tidal volume or of of an on volume mmHg). The surgery was The PLMA ™ was when the patient was fully was by injection of and a continuous of After the patient on the continuous positive airway pressure with was and was for three was in both snoring and stridor during not of dyspnea after surgery and was fully that preoperative and anesthesia management of the case described are and with and preoperative during and was and the of the stenotic with CT of the trachea in to were may be to a safer anesthesia management that the and can be Nevertheless, may be because the of airway obstruction during not that there will be no airway obstruction during anesthesia. have reports of airway obstruction in patients with preoperative of airway this case, the CT and preoperative that airway obstruction is but it might have safer to induce anesthesia by of increasing concentrations of a anesthetic as and then to a neuromuscular blocking after that no airway obstruction has may be two major possible problems with the anesthesia management performed by Drs. and may occur beyond the stenosis, when the ventilation is can be reduced by the is increasing the expiratory In this case, because the stenosis had a the ventilation and ventilation volume was breathing might have a choice ventilation had during possible is that the use of the PLMA ™ might have difficult not likely in this the device had or airway obstruction at the stenotic had If there are about to the patient's or about a prolonged operation I would use a backup method of a tube-exchange catheter beyond the stenosis and an endotracheal tube with its tip proximal to the continuous positive airway to airway was for three tracheal intubation not the choice of continuous positive airway pressure than of a tube to the trachea after possible solution that is potential complications I will to the following I do not plans would Drs. and have the of their plans In most in this case is not A but the plans to A or is for the to have a as a before induction of first is that of this patient's at the of supraglottic and problems to both difficult mask ventilation and difficult will be and severe the airway is in this obese patient who will have a of a tube beyond his tracheal may be the most there are two patient that I the that the tracheal only 5 mm in its minor is mm in its major diameter to that it will a larger endotracheal tube than with an diameter of 5 The trachea is a and and who has tracheal will confirm that it will a larger diameter tube than its the that the patient no limitation to his daily activities indicates that gas flow is than of the patient's consider use of the PLMA ™ as the airway anesthesia. The PLMA ™ is airway and I have with it for both difficult airway is in it that I have use of the ™ Mask because I that its and safety is to that of the PLMA ™. Despite I its use for this case because I was that it with the patient in the prone position, would be and might with not consider the of use of PLMA ™ with an airway exchange catheter in place through the vocal in case was is and a level of Despite I was required to this patient I would still tracheal intubation before a in the prone position. I have used the PLMA ™ in approximately patients in the prone position and I that it has used in of patients in the prone the patients in were at low risk and the largest is airway obstruction in three patients In the patient in this case has an increased risk of problems with both ventilation and degrees of and airway during surgery in the prone position would likely to airway If airway obstruction in this would likely be and airway is likely difficult to in the supine position in Despite I would be that problems in the prone position, would be so difficult to that the patient's would be at Despite the by intubation I would tracheal intubation in this spontaneous breathing induction of anesthesia, for a With the of I have a for use of a dose of target-controlled while maintaining spontaneous ventilation. are only of this of target-controlled of propofol over induction is that spontaneous ventilation is The has over propofol that the of anesthesia. increasing depth of anesthesia is of the patient's ventilation. of increase of the depth of anesthesia to be titrated by the than by the that is the anesthesia to the patient to anesthesia via an airway that was and has airway are so increased and the complications to during induction are In patients will ventilation when still responsive to verbal confirmation of to or of increasing and airway (e.g. , are and than during the to to problems with the airway PLMA ™ is a device with a in management of the difficult there is in PLMA ™ it is that insertion can be more difficult than for supraglottic airway insertion enable a insertion with the PLMA ™ of lower than that for the is that the use of a first pass with the PLMA ™, increasing to increase in in I consider first to be I insert the PLMA ™ over a the type of is to the risk of AIC is the tube to use to intubate via a supraglottic airway and intubate narrow has the diameter than of endotracheal tube that will over a size fiberscope and its ID that it not during on the use via the and PLMA ™ in difficult airway management is in two placed it oxygenation and on placement of a larger endotracheal tube over or a an airway exchange catheter through by the minor diameter of the trachea the of with ventilation or If ventilation becomes at after induction or intubation with an AIC is not possible, is before another are before have I would at an endotracheal tube, tracheal the of loss of the airway, with will be ventilation using a (VBM Medizintechnik, Sulz, the a so that the may only the pressure to the the risk, and of would be via the Ravussin cannula, placed before induction of anesthesia. and a is not an to place a cricothyroid cases of difficult airway management which to of cases with and in of cases a surgical airway was but was placed to and ventilation performed in were with a incidence of Although cases are by the is for and a patient before is a The of insertion of a cricothyroid cannula for difficult airway management has is a of management of patients with airway is performed in the awake is and is the catheter would be placed under as this position and in this case that may not be is more when the is before difficult that may I to use the cricothyroid cannula I would not with but would be to that full had over or before the placing a on the patient's and is a to confirm would to severe in anesthesia, there may be no or appropriate The airway airway management strategies for this patient. this not airway through this case scenario, of the is that we that ventilation would be possible during anesthesia Despite we airway management strategies and in plans in case of this is either because preoperative of airway size and may be in ease of ventilation during general anesthesia or because the airway management and for managing tracheal stenosis is in patients with severe tracheal stenosis, normal gas exchange is by Therefore, the presence of hypercapnia in preoperative patients indicates the potential for of both spontaneous and mechanical ventilation during general anesthesia. In the to breathing through a narrow airway is during general anesthesia and than that during because such as and are and is and breathing through a of mm ID and cm in or mm ID and cm in reduced the ventilation by and during general anesthesia, were and The by and and confirm that the through which patients can breathe an increase in mm for breathing through a is by the with of both inspiratory and expiratory and the increase in Although the patient's or during assisted and ventilation, size of the stenosis for breathing may not be by the I that no has the stenosis for mechanical ventilation in and patients and the to be in the can we assess and severity of tracheal with mild to tracheal stenosis have symptoms such as patients with severe tracheal stenosis may present stridor and dyspnea during breathing symptoms may not be for severity of tracheal assess the severity of the stenosis. have for the presence and the severity of an airway stenosis. CT the airway information the and of the airway and the the such as CT and can more airway and the airway a fiberoptic for the and the the and the of stenotic of the trachea in patients who trachea surgery were to be mm in and mm, of the and of the stenotic airway by the of the tracheal stenosis on breathing during general anesthesia is difficult to by the size is by the pressure the airway and its A extrathoracic airway during and during because the pressure during and during In the airway caliber and is in the intrathoracic airway. Therefore, limitation not occurs in the extrathoracic airway during and in the intrathoracic airway during airway is during forced expiratory and inspiratory particularly when of the airway caliber is In this may be for the site of airway and airway that the during a of forced expiratory and inspiratory were in 12 patients with extrathoracic airway than of normal Two patients with intrathoracic had than which increased to more than after of the and insertion of tracheal In two patients with tracheal stenosis, both and were but not from normal to the flow-volume loop in patient had in both and and a normal airway stenosis and for of the airway Nevertheless, is required for of the because can be by patient a direct the tracheal by the CT and in with but in the supine position with the sitting position and in after mass airway obstruction after induction of anesthesia in with than tracheal the patient with a trachea by lower and tracheal should not have general anesthesia before the airway. In may be for tracheal and for the risk of airway after induction of anesthesia, but are the airway is the severity of limitation is by airway the a and the of the airway stenosis, and might be used as a for airway size of the of the of stenotic and airway to airway may have over information as an for upper airway that was than in patients with upper airway to a normal breathing through an of than mm diameter (fig. through a in mechanical ventilation during general anesthesia, increased the to more than In patient with 3 cm tracheal stenosis with of is as = The is than that in normal and to breathing through at to 8 mm Therefore, this possible breathing or mechanical ventilation during general anesthesia, airway of the tracheal stenosis can information for perioperative airway management strategies (fig. 1). of more than to 4 mm may a potential of mechanical ventilation after induction of general anesthesia, this to be and should be considered in we anesthetic management of a patient with tracheal stenosis and airway management strategies of and accurate of airway and breathing during general anesthesia in the patient with tracheal stenosis to be the for the airway management For patients with difficult in preoperative airway as a is when with the in airway management and Cook United United and United with of the case assisted in of and of the of for his with of this