UBP 1.4 (Long Form): Pulmonary – Mediastinal Mass Flashcards
Secondary Subject -- Tobacco Use / Down Syndrome / Myasthenia Gravis / Atlanto-axial Instability / Bronchospasm / Laryngospasm / Flow Volume Loops / Cholinergic Crisis / Negative Pressure Pulmonary Edema
Intra-Operative Management:
How would you provide anesthesia for this case?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
I would perform this case under local anesthesia with little to no sedation if at all possible.
I have multiple concerns about proceeding with this case under general anesthesia, including the following:
- the occurrence of presyncope and dyspnea with supine positioning, FEV1 and PEF < 50% of expected, and 50% tracheal compression seen on CT all suggest significant risk of respiratory and/or cardiac compromise with the induction of general anesthesia
- (the cardiac dysfunction secondary to the congenital defects often associated with Down syndrome or the cardiac effects of myasthenia gravis could also contribute);
- the characteristic abnormalities often associated with Down’s syndrome, such as a macroglossia, sublottic stenosis, micrognathia, and atlanto-axial instability, could complicate mask ventilation, laryngoscopy, and endotracheal tube placement;
- her severe GERD, dysphagia, and the potential for difficulty laryngoscopy place her at increased risk for aspiration;
- her moderate-to-severe asthma increases her risk for bronchospasm; and
- her macroglossia and the soft tissue defects often associated with Down’s syndrome (hypotonic and redundancy), increase the risk of rapid airway obstruction and hypoxemia with the induction of anesthesia.
–
However, given the patient’s minimal cooperation, performing the procedure under local anesthesia may be difficult or impossible.
- Xtra Q – What are the effects of Down Syndrome on airway management?*
- –*
- Even if you think you won’t be allowed to do something (e.g. local, awake FOB), demonstrate knowledge anyway – Don’t skip steps.*
Intra-Operative Management:
The surgeon explains that the patient has absolutely refused to go through the procedure with just local anesthesia.
What would you do?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
Assuming there is no extrathoracic adenopathy, and that an intrathoracic biopsy is required (cervical and supraclavicular nodes can sometimes be biopsied instead of the mass),
I would make the surgeon, the patient, and her family aware of my concerns, and suggest chemo, radiation, or steroid therapy to reduce the size of the mass prior to performing any surgical procedure.
I would also make sure that the resolution of concerning symptomatology and successful reduction of the tumor was confirmed by CT or MRI prior to rescheduling the case.
While the rapid tumor lysis induced by pretreatment with radiation therapy, steroid administration, and chemotherapy can relieve mass compression of the airway and cardiovascular structures,
it can also affect the accuracy of future histological diagnosis,
potentially compromising the efficacy of subsequent treatment.
Even though there is some evidence to suggest that the histological evaluation of the tumor is unaffected if the biopsy is taken within 72 hours of initiating treatment, many surgeons remain unconvinced.
Therefore, in making a decision, the risk of proceeding without pretreatment must be weighed against the risk of diagnostic inaccuracy.
11:28 Commentary on Intra-Op – Xtra Q – Would you provide a general anesthetic? ** Practice answering this question – Wide River – Requires organization & chronological format & succinct answer.
Intra-Operative Management:
You suggest pretreatment with steroids, chemotherapy, or radiation therapy to reduce the size of the tumor prior to proceeding with the procedure.
The surgeon, however, says that it is vitally important to make an accurate tissue diagnosis and will not agree to this plan.
You subsequently determine that general anesthesia is required.
Would you administer an anticholinergic for aspiration prophylaxis?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
I would NOT utilize an anticholinergic drug for aspiration prophylaxis because –
these drugs reduce lower esophageal sphincter tone and have not been shown to reduce acidity or gastric volume in patients at increased risk for aspiration.
For these reason, the ASA guidelines no longer recommend their use in the prevention of aspiration.
An anticholinergic would potentially be useful in reducing –
- airway secretions (potentially improving intubating conditions and reducing airway inflammation) and
- airway hyperreactivity (secondary to reduced vagal tone and inhibition of muscarinic cholinergic receptors) in this patient with anticipated difficult airway management and asthma.
Moreover, since significant bradycardia occurs in up to 50% of Down’s syndrome patients being induced with inhaled sevoflurane, it would be potentially helpful to have an anticholinergic such as atropine readily available.
However, if I believed or learned that this patient did have myasthenia gravis, I would avoid the administration of anticholinergic drugs since they would potentially lead to increased muscle weakness and bulbar symptomatology.
Intra-Operative Management:
How would you evaluate her for atlanto-axial instability?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
I would begin by reviewing her previous anesthetic record (appendectomy) for any indication of difficult airway management and/or symptoms of atlanto-axial instability.
I would also review any existing neck radiographs for any evidence of subluxation, such as an anterior atlantodental interval > 4-5 mm in any lateral view
(many of these patients will have received screening radiographs based on the American Academy of Pediatrics recommendation that all Down’s syndrome patients be screened between the ages of 3-5 years).
Next, I would perform a thorough history and physical exam to identify any signs or symptoms of cord compression, such as:
- gait anomalies;
- a preference for the sitting position
- clumsiness;
- fatigue with ambulation;
- numbness, tingling, or weakness in the extremities;
- hyperreflexia (e.g. increased deep tendon reflexes), and/or
- signs of clonus.
Finally, assuming she was cooperative, I would have her perform full neck flexion and extension maneuvers to determine whether the signs or symptoms of cord compression could be elicited (e.g. pain and/or motor or sensory deficits).
If during this process she exhibited any signs or symptoms consistent with cord compression, I would delay the case and request repeat cervical imaging and a neurosurgical evaluation of her cervical spine.
- Note: Even if neck radiographs are negative, it may be a false negative.*
- Recall – this is NOT an emergent case, so if you can do anything to optimize, do it.*
Intra-Operative Management:
She has never undergone any cervical imaging to screen for instability.
Would you require imaging prior to surgery?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
While it would be reasonable to obtain cervical imaging in a patient with Down’s syndrome who has never been screen
(imaging would be utilized to identify an increased anterior atlantodental interval, the neural canal width, and any signs of atlantooccipital instability),
I would not necessarily require it for this case as long as the history and physical exam did not identify any signs or symptoms consistent with cervical instability.
I would, however, proceed with extreme caution, making every effort to avoid excessive flexion, rotation, or neck extension.
This would be of particular concern when intubating this patient with the potential for difficult airway management.
Intra-Operative Management:
You discover that you were misinformed and there are previous radiographs taken when she was 4 years old showing an anterior atlantodental interval (AADI) of 6 mm.
However, she has never been symptomatic.
Would you delay the case for repeat cervical spine radiographs?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
While it would be reasonable to repeat cervical imaging when past cervical spine radiographs showed an abnormal AADI (to identify any other signs of cervical instability and/or if there was an increase in the AADI as compared to previous films),
I would not delay this needed procedure unless her history and/or physical exam revealed symptomatology consistent with cord compression.
I would make this decision based on –
- the patient’s lack of symptomatology and
- an understanding that plain cervical films have proven to be very unreliable in predicting cord compression.
However, in proceeding, I would take every precaution to minimize head and neck movement during the case (especially laryngoscopy).
Intra-Operative Management:
She complains of numbness and tingling in her arm with full neck extension.
What would you do?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
Recognizing that this Down’s syndrome patient’s symptomatology is consistent with cervical spine instability,
I would delay this non-emergent procedure until she had received a full cervical spine evaluation by a surgical specialist.
In the case of a surgical procedure that could not be delayed,
I would proceed with the goal of minimizing neck flexion, extension, and rotation throughout the case.
Intra-Operative Management:
On further exam you decide that the numbness and tingling she was experiencing was due to blood pressure cuff inflation on the affected arm.
So, you decide to proceed with the case.
How will you intubate and induce this patient?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
(Practice this question 11:28-15:45 & 19:00 - on)
I would:
- optimize the patient’s asthmatic condition;
- provide aspiration prophylaxis (GERD and the impairment of protective airway reflexes that may occur with autoimmune-mediated bulbar palsy);
- administer an antisialogogue to decrease oral secretions and increase the effectiveness of topically applied local anesthetics (I would avoid this drug if I believed her to have myasthenia gravis); and
- ensure adequate intravenous access and the presence of fluids, inotropes, and vasopressors (possible mass-induced cardiac compression).
Given my concerns about potential difficult mask ventilation (mass compression and the tissue hypotonia and redundancy often associated with Down’s syndrome) and/or difficult laryngoscopy (macroglossia, subglottic stenosis, and cervical spine precautions), I would –
- have difficult airway equipment in the room, including a fiberoptic scope, armored endotracheal tubes, long endotracheal tubes, endobronchial tubes, and microlaryngeal tubes
- (a variety of endotracheal tubes – some with reduced diameter and some of longer length – should be available in order to facilitate passage through a compressed or stenotic airway and/or advance the tube beyond the area of mass compression; also endotracheal tubes with a reduced diameter would be helpful if this patient with Down syndrome had subglottic stenosis).
Moreover, I would –
- have the surgeon in the room with a rigid bronchoscope
- (may be useful in identifying the most patent mainstem bronchus, stenting the airway, and/or as a conduit for jet ventilation) and
- a sternal saw
- (in the case of cardiopulmonary collapse, it may become necessary to perform a sternotomy and relieve the mass compression by lifting the mass).
Additionally, I would –
- place the patient in the position in which she was most comfortable to minimize mass compression of her airways, heart, or great vessels
- (she would be positioned as to minimize dyspnea and/or presyncope);
- leave the patient’s cart next to the OR bed in case prone becomes necessary;
- cannulate the femoral arteries under local anesthesia with cardiopulmonary bypass pump on stand-by should it become necessary
- (some experts would suggest that cardiopulmonary bypass should be initiated prior to induction in high risk patients);
- provide adequate airway analgesia;
- evaluate the airway with the fiberoptic scope
- (determine the location and degree of airway compression; identify the most patent mainstem bronchus in case it became necessary to advance a breathing tube into one lung in order to bypass the area of mass compression);
- intubate the patient with the fiberoptic scope, using an appropriately sized armored endotracheal tube;
- perform an inhalational induction
- (keep in mind that bradycardia occurs in up to 50% of Down’s syndrome patients undergoing inhalational induction; and
- achieve a depth of anesthesia sufficient to prevent bronchospasm, while at the same time maintaining spontaneous ventilation, recognizing that the transpulmonary gradient created during spontaneous ventilation aids in maintaining airway patency in the presence of mass compression.
Intra-Operative Management:
Would an awake fiberoptic intubation be the best approach?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
- (note awake FOB may be an issue for an asthmatic patient)*
- –*
Assuming general anesthesia were required,
I believe a fiberoptic awake intubation would be the best approach to securing her airway.
The advantages of this approach for this patient with an anterior mediastinal mass, Down syndrome, and severe gastroesophageal reflux disease include:
- minimizing distraction of the cervical spine when there is potential atlanto-axial instability;
- minimizing the risk of aspiration by securing her airway prior to the initiation of general anesthesia;
- providing a means to assess the level and degree of tracheobronchial compression, identify the most patent mainstem bronchus (the latter is important information for planning subsequent rescue procedures), and facilitate intubation distal to the area of obstruction (which may require passage into the most patent mainstem bronchus); and
- minimizing the risk of mass-induced cardiopulmonary complications by utilizing a technique that is easily aborted, maintains spontaneous ventilation, and avoids the deleterious cardiopulmonary effects of general anesthesia (i.e. reduced preload and altered respiratory mechanics that favor airway collapse).
Intra-Operative Management:
The patient refuses an awake intubation. What will you do?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
I would attempt to explain the benefits of placing the ETT prior to induction and reassure her that I would do everything I could to make her comfortable during the awake intubation.
If she still refused, I would:
- optimize the patient’s medical conditions and ensure the appropriate difficult airway equipment was present, as previously discussed;
- have the surgeon in the room with a rigid bronchoscope and a sternal saw;
- take precautions to minimize head and neck movement (potential for atlanto-axial instability);
- place her in the position in which she is most comfortable to minimize mass compression of the airways, heart, or great vessels (i.e. sitting or lateral position);
- cannulate the femoral arteries under local anesthesia with cardiopulmonary bypass pump on stand-by should it become necessary
- administer an antisialogogue to reduce airway secretions; and
- induce the patient with a small dose of ketamine followed by a volatile agent.
Again, my goal would be to achieve a depth of anesthesia sufficient to prevent bronchospasm, while maintaining spontaneous respirations and avoiding pulmonary aspiration and excessive neck movement.
Once an adequate depth of anesthesia was achieved, I would –
- place an armored endotracheal tube.
Clinical Note:
- Inducing the patient with an inhalational agent, ketamine, or dexmedetomidine would be reasonable strategies when the maintenance of spontaneous ventilation is vital.
- In this case, the use of dexmedetomidine would probably not be appropriate considering the patient’s positional presyncope and the hypotension often associated with dexmedetomidine.
Intra-Operative Management:
Shortly after induction, but prior to placement of the ETT, airway movement ceases and you are unable to ventilate her. What will you do?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
Recognizing that this cessation of airway movement could be secondary to mass compression, bronchospasm (asthmatic patient, risk of aspiration during induction), soft tissue obstruction (macroglossia and the tissue hypotonia/redundancy associated with Down’s syndrome), or laryngospasm (GERD), I would:
- place an oropharyngeal airway and attempt to hand ventilate with 100% oxygen;
- auscultate the chest;
- place the patient in the position identified preoperatively that minimizes her dyspnea and presyncope (an attempt to minimize mass compression);
- take precautions to minimize head and neck movement (potential for atlanto-axial instability);
- perform laryngoscopy to identify any laryngospasm.
- If there were no apparent laryngospasm, I would – place an endotracheal tube and attempt to ventilate.
- If I were still unable to ventilate, I would – pass a fiberoptic bronchoscope through the endotracheal tube to identify any mass-induced obstruction.
- If there were no apparent obstruction, I would – consider that this asthmatic patient is likely experiencing severe bronchospasm and apply positive pressure ventilation, deepen her anesthetic, and administer albuterol and/or epinephrine (while bronchospasm usually presents with some airway movement and rhonchi, the spasm may be severe enough to result in negligible airway movement and, therefore, no rhonchi).
- However, if I confirmed or believed that my inability to ventilate this patient was secondary to mass-induced obstruction, and that there was insufficient time to wake the patient up, I would – attempt to advance the endotracheal tube or a rigid bronchoscope beyond the obstruction (when advancing the airway device beyond the carina, attempt to place it in the most patent bronchus) and
- consider repositioning the patient in the lateral or prone position to relieve mass compression (being careful to limit cervical spine movement in this patient with atlanto-axial instability).
- If none of these measures were successful, I would – ask the surgeon to perform emergency sternotomy and manually elevate the mass.
- At the same time, I would – ask the perfusionist to take the necessary steps to initiate cardiopulmonary bypass (via the femoral arteries).
Post-Operative Management:
You administer albuterol and epinephrine, and the bronchospasm abates.
The procedure is completed and the mass is identified as a thymoma.
Would you extubate this patient immediately following the procedure?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
Recognizing that the return of spontaneous ventilation and chest wall tone should help in maintaining airway patency,
I would consider removing the endotracheal tube with the patient in the reverse-trendelenburg position as soon as she met standard extubation criteria.
However, I would keep in mind that complications involving the airway may occur more frequently during emergence and in the postoperative period.
This is especially true following a biopsy procedure under general anesthesia, where tumor compression has not been relieved by debulking or excision, and compression of the airway or cardiovascular structures may be further exacerbated by airway edema, surgically-induced tumor edema and/or hemorrhage, and the residual effects of general anesthesia (i.e. reduced lung volumes; increased muscle weakness if she is suffering from myasthenia gravis – 30-65% of patients with thymoma develop myasthenia gravis, and her difficulty swallowing and shortness of breath are consistent with myasthenia gravis).
Given her risk of aspiration, the possibility that she suffers from myasthenia gravis, and recognizing that she remains at risk for airway compression from the mediastinal mass,
I would prepare for emergent re-intubation, delay extubation until she was uflly awake, and
administer an anticholinesterase if I believed her respiratory efforts were weaker than expected (an anticholinesterase should help with respiratory weakness resulting from myasthenia gravis).
Since an awake extubation places her at risk for bronchospasm, I would administer narcotics, a B2-agonist, and intravenous lidocaine prior to extubation in order to blunt any irritation of her airway.
Post-extubation, I would require vigilant monitoring of the patient.
Post-Operative Management:
You extubate the patient after administering a dose of pyridostigmine to treat any associated myasthenia gravis.
Following removal of the ETT, she develops laryngospasm and you are unable to ventilate.
What would you do?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
If she was experiencing laryngospasm (possibly secondary to aspirate or respiratory secretions irritating the vocal cords), I would:
- suction her airway to remove any debris, blood, and/or secretions (these can stimulate the superior laryngeal nerve with a subsequently exaggerated reflex glottic closure - laryngospasm);
- apply positive pressure mask ventilation, which may prove beneficial by acting as a pneumatic splint and helping to maintain airway patency;
- deepen her anesthetic by increasing the concentration of the volatile agent and
- administer intravenous lidocaine (1.0-1.5 mg/kg), with the goal of blunting any exaggerated glottic closure reflex
- (while propofol may also help to diminish this reflex, I would avoid it in this case due to the importance of maintaining spontaneous ventilation in the setting of a large anterior mediastinal mass); and
- initiate a forceful jaw thrust (being careful to avoid distraction of the cervical spine in this patient with potential atlanto-axial instability) with bilateral digital pressure on the body of the mandible just anterior to the mastoid process (Larson’s maneuver).
- In the case of persistent spasm and worsening hypoxia, I would – call for help and
- attempt to gently pass an ETT through the closed vocal cords.
I would avoid the use of succinylcholine or a nondepolarizing muscle relaxant, if at all possible, due to my concerns about the potential for airway collapse with the prolonged cessation of spontaneous ventilation (anterior mediastinal mass).
However, if I was unable to secure the airway and I believed muscle relaxation was required (to relax the laryngospasm and/or facilitate intubation), I would –
- administer a small dose of succinylcholine or a nondepolarizing muscle relaxant.
Clinical Notes:
- Patients with myasthenia gravis tend to be resistant to succinylcholine possibly due to the reduction in acetylcholine receptors at the post-synaptic neuromuscular junction (the 95% effective dose is 2.6 times higher, the 50% effective dose is 2.0 times higher).
- The appropriate dose for rapid sequence induction should be increased to 1.5-2.0 mg/kg. It is not necessary to double the dose since the usual dose in patients without myasthenia gravis is already 3-5 times the ED95.
- The duration of action of both succinylcholine and mivacurium may be prolonged when a patient with myasthenia gravis is receiving pyridostigmine to treat their condition. This is secondary to inhibition of pseudocholinesterase (plasma cholinesterase) by the cholinesterase inhibitor.
- In the case of severe laryngospasm with complete glottic closure, the application of positive-pressure mask ventilation could theoretically prove ineffective or even counter-productive. In this setting, the positive pressure you generate may press the aryepiglottic folds more firmly together, contributing to ongoing airway obstruction. When the laryngospasm results in incomplete glottic closure (usually associated with high pitched inspiratory stridor), positive pressure mask ventilation would be beneficial by acting as a pneumatic splint and helping to maintain airway patency.
Post-Operative Management:
You are unable to break the laryngospasm. There is no succinylcholine available.
Would you administer a nondepolarizer to break the spasm?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
Given my ongoing concerns about the potential for airway collapse with the cessation of spontaneous ventilation (anterior mediastinal mass),
I would only administer a nondepolarizer to this patient as a treatment of last resort.
Moreover, if she has myasthenia gravis (she has a thymoma and her difficulty swallowing and breathing may be partly or completely due to myasthenia gravis), she may be extremely sensitive to nondepolarizing muscle relaxants.
Therefore, I would consider administering a small dose of an intermediate-acting nondepolarizing muscle relaxant only if –
- her laryngospasm persisted despite other interventions,
- she was becoming hypoxic,
- intubation without muscle relaxation proved impossible, and
- succinylcholine was unavailable.
Clinical Notes:
- For patients with myasthenia gravis, the normal dose of nondepolarizing muscle relaxant should be reduced by one half to two thirds (some sources say one fifth).
- Chronic mass compression can lead to weakened airway wall structures whose patency is increasingly dependent upon the negative intrathoracic pressure created during spontaneous ventilation.
-
When muscle relaxation is required for a patient with an anterior mediastinal mass:
- attempt to pass breathing tube beyond the area of mass compression,
- make sure the patient tolerates manual positive pressure ventilation, and
- avoid long acting muscle relaxants.
Post-Operative Management:
You break the laryngospasm without needing to intubate her. Later, you are called because she has become dyspneic. What is your differential?
- (A 36-year-old female presents for biopsy of an anterior mediastinal mass.*
- PMH: The patient’s mother says that her daughter is a smoker, has Down syndrome, and gets short of breath at times. She has always attributed her shortness of breath to her smoking or asthma. The patient’s asthma is moderate to severe and she goes to the emergency room every few months with severe asthmatic attacks. For the past six months she has had occasional difficulty swallowing. Her mother says she has severe acid reflux and that her meds include Tums.*
- Anesth. Hx: The patient had an appendectomy 9 years ago without complication.*
- PE: VS: P = 87, BP = 110/70 mmHg, R = 12, T = 36.6 °C*
- General: The patient becomes lightheaded and dyspneic when placed in the supine position*
- Head/Neck: No signs of neck or facial edema*
- Airway: Mallampati II, large tongue*
- CV: RRR*
- Lungs: Expiratory wheezing*
- Lab: Normal*
- PFTs: FEV1 and PEF less than 50% of expected in the supine position*
- CT: Large anterior mediastinal mass with 50% tracheal obstruction at the level of the carina; no pericardial effusion noted.)*
My differential would include:
- mass obstruction, secondary to hemorrhage (occurring secondary to surgical manipulation of the tumor and/or surrounding soft tissue) or the tumor (positioning and/or swelling);
- bronchospasm, secondary to her asthma or aspiration;
- laryngospasm;
- upper airway obstruction, secondary to her macroglossia and the tissue hypotonia and redundancy associated with Down’s syndrome;
- negative-pressure pulmonary edema, occurring secondary to forceful inspiratory effort during severe laryngospasm;
- airway edema;
- tracheobronchomalacia;
- an exacerbation of myasthenia gravis in this patient with a thymoma (although myasthenia gravis has yet to be diagnosed);
- cholinergic crisis (recent administration of pyridostigmine);
- pneumothorax (a known complication associated with the biopsy of an anterior mediastinal mass)
- atelectasis;
- cardiogenic pulmonary edema, secondary to mass effects on the heart and/or an unrecognized or worsening congenital cardiac defect (up to 50% of Down’s syndrome patients have congenital heart disease);
- inadequate pain control (pain and anxiety can lead to dyspnea secondary to an associated increase in airflow velocity through a partially obstructed airway (airway resistance increases in direct proportion to gas flow);
- pulmonary embolism; and
- residual drug effects.
