UBP 3.4 (Long Form): Pulmonary – Mediastinoscopy

Question 1

Intra-Operative Management:

What special considerations would you have concerning monitoring?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 1

Given this patient’s increased risk for hemodynamic instability (poorly controlled hypertension, possible autonomic neuropathy, and the intraoperative hypotension associated with ACE inhibitors) and cerebral ischemia (carotid artery disease, poorly controlled hypertension, possible superior vena cava syndrome, potential for innominate artery compression during mediastinoscopy),

I would place a 5-lead ECG and a left radial arterial line to facilitate the rapid identification and treatment of any cardiac ischemia and/or significant hypotension.

Moreover, I would monitor the tracing of a pulse oximeter placed on his right upper extremity to quickly identify any compression of the innominate artery, recognizing that this is a known complication of mediastinoscopy.

I would also monitor the patient’s peak inspiratory pressure for signs of tracheal compression.

Since patients with autonomic neuropathy are at increased risk for intraoperative hypothermia (due to impaired peripheral vasoconstriction), I would closely monitor his temperature.

Finally, if muscle relaxation were required for the case, I would utilize a nerve stimulator, recognizing that patients with Lambert-Eaton myasthenic syndrome are very sensitive to both depolarizing and nondepolarizing muscle relaxants.

Clinical Note:

• Some form of monitoring of the right radial pulse is mandatory during mediastinoscopy due to the risk of innominate artery compression with subsequent cerebral ischemia.
• Methods that may be employed include:
  
  1. placement of a right radial arterial line,
  2. monitoring the plethysmographic tracing of a pulse oximeter on the right hand, or
  3. continuous palpation of the right carotid or right radial pulse.

Question 2

Intra-Operative Management:

Do you think this patient is experiencing superior vena cava syndrome?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 2

This patient’s worsening cough, shortness of breath, jugular venous distention, and opacification of upper extremity collateral veins on CT are all consistent with superior vena cava syndrome.

A definitive diagnosis could be established by venography.

Other signs and symptoms that may be present in a patient with superior vena cava obstruction would include:

1. headache;
2. facial neck, and upper limb edema;
3. chest pain;
4. dysphagia;
5. lightheadedness;
6. orthopnea;
7. hoarseness;
8. nasal stuffiness;
9. nausea;
10. pleural effusons;
11. papilledema;
12. visual disturbances;
13. mental confusion, and
14. facial cyanosis.

Question 3

Intra-Operative Management:

The surgeon confirms that the patient is suffering from superior vena cava syndrome.

Does this concern you?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 3

I have several concerns related to this patient’s superior vena cava syndrome including:

1. complicated airway management secondary to airway edema,
2. unreliable drug delivery through intravenous lines in the upper extremities (primarily in the setting of surgical damage to the vessel),
3. the potential for massive hemorrhage secondary to damage to any one of several major blood vessels in the surgical field (i.e. azygos vein, innominate artery, aorta, superior vena cava, and pulmonary artery),
4. compromised cerebral perfusion in this patient with carotid artery disease (impaired drainage of cerebral veins → increased cerebral venous pressure → increased ICP and impaired cerebral perfusion), and
5. an increased risk of postoperative respiratory complications, such as acute laryngospasm, bronchospasm, and airway obstruction (secondary to airway edema and/or mass compression).

Given these concerns, I would –

1. prepare for difficult airway management and minimize manipulation of the airway as much as possible to prevent exacerbating any airway edema (especially if there were concomitant tracheal compression, a.k.a. superior mediastinal syndrome);
2. place two large-bore intravenous catheters, with at least one of the lines inserted in his lower extremity (providing reliable delivery of drugs, fluids, and blood products even in the setting of a surgically damaged superior vena cava);
3. type and cross match blood to prepare for possible massive hemorrhage;
4. maintain the patient in the head up position to facilitate venous drainage and avoid increased airway edema and intracranial pressures;
5. employ cautious fluid management, recognizing that too much fluid would lead to venous engorgement and edema, while too little fluid would lead to decreased preload;
6. avoid coughing and bucking during emergence, recognizing that either could lead to exacerbated venous congestion and acute airway obstruction; and
7. maintain endotracheal tube placement and mechanical ventilation during the immediate post-operative period (unless the obstruction of the superior vena cava had been relieved).

Question 4

Intra-Operative Management:

Would general or local anesthesia be preferable for this case?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 4

Given the risk of increased airway edema and acute airway obstruction associated with superior vena cava syndrome,

I would prefer to avoid instrumentation of the airway and perform the procedure under local anesthesia (this is possible for anterior mediastinoscopy, but not for cervical mediastinoscopy, which is the most common approach).

Moreover, this technique would avoid exposing this patient with cerebrovascular disease and increased risk for hypotension (secondary to poorly controlled hypertension, possible autonomic neuropathy, SVC syndrome, and ACE inhibitor administration) to the hemodynamic instability associated with laryngoscopy, induction, and general anesthesia;

allow more reliable monitoring of neurologic function (i.e. an awake patient); and

avoid the increased risk of aspiration associated with general anesthesia in this patient with possible autonomic neuropathy (LES and malignancy are associated with autonomic neuropathy; this patient’s symptoms of constipation and orthostatic hypotension are consistent with this condition).

However, there are several advantages to performing the procedure under general anesthesia with controlled positive-pressure ventilation, including:

1. increased flexibility for surgical manipulations,
2. decreased risk of surgical trauma resulting from sudden patient movement,
3. reduced risk of air embolism (the tip of the mediastinoscope is intrathoracic, placing the patient at risk for venous air embolism in the presence of venous bleeding and the negative intrathoracic pressure created during spontaneous ventilation),
4. improved conditions for the management of a significant complication like massive hemorrhage, and
5. reduced risk of coughing during the procedure (coughing during the procedure can lead to venous engorgement with subsequent increased risk of surgical damage to local vessels).

Question 5

Intra-Operative Management:

Assume that you have decided to perform general anesthesia.

How will you induce and intubate the patient?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 5

Given this patient’s multiple comorbidities, I would:

1. ensure the presence of –
   
   • difficult airway equipment (airway edema associated with superior vena cava syndrome),
   • a radial arterial line (increased risk for hemodynamic instability, poorly controlled hypertension, carotid artery disease), and
   • adequate lower extremity intravenous access (increased risk for massive hemorrhage, superior vena cava syndrome);
2. provide aspiration prophylaxis (his constipation and orthostatic hypotension are consistent with autonomic neuropathy, a condition associated with both malignancy and LES);
3. position the patient in reverse trendelenburg to optimize cerebral drainage (SVC syndrome and carotid artery disease) and reduce airway edema (head up positioning helps to reduce the airway edema associated with SVC syndrome);
4. provide adequate airway analgesia to prevent a sympathetic response that may exacerbate his hypertension;
5. perform an awake intubation to secure the airway of this patient at increased risk for difficult airway management and aspiration prior to induction (the presence of SVC syndrome increases the risk of difficult airway management); and
6. induce him with narcotics and etomidate, with the goal of minimizing the risk of hypotension.

Question 6

Intra-Operative Management:

Would you administer a muscle relaxant as part of your anesthetic maintenance?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 6

While the administration of a depolarizer or nondepolarizer for muscle relaxation during the procedure would reduce the risk of surgical trauma secondary to coughing (coughing leads to venous engorgement, thereby increasing the risk of vascular trauma by the mediastinoscope) or sudden patient movement,

I would prefer to avoid administering either of these medications to this patient suffering from LES.

Not only are patients with LES extremely sensitive to both depolarizers and nondepolarizers, but also the reversal of neuromuscular blockade is less effective, particularly in patients being treated with 3,4-diaminopyridine or an anticholinesterase.

Since this patient is already at increased risk for postoperative respiratory complications due to his superior vena cava syndrome and LES,

I would prefer to avoid introducing any additional drugs that may further compromise his respiratory function.

Moreover, the muscle relaxation associated with volatile agents is often exaggerated in patients with LES, making the administration of nondepolarizing agents unnecessary.

If the administration of a nondepolarizer were deemed necessary, I would administer small doses, monitor his neuromuscular function carefully with a nerve stimulator, and evaluate his ventilatory function thoroughly prior to extubation.

Question 7

Intra-Operative Management:

The surgeon insists on muscle relaxation.

Shortly after induction, he is advancing the mediastinoscope when the right radial arterial line indicates a blood pressure drop from 145/90 mmHg to 90/65 mmHg.

What do you think is going on?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 7

There are a number of things that could be causing or contributing to his hypotension, including:

1. surgical compression of the innominate artery;
2. a vagal reflex resulting from manipulation of the trachea, great vessels, or vagus nerve;
3. anesthetic-induced cardiovascular depression;
4. autonomic neuropathy associated with the malignancy and/or LES
   
   • (patients with autonomic neuropathy may be unable to compensate for the cardiovascular depression associated with anesthesia due to impaired peripheral vasoconstriction and baroreceptor function);
5. reduced preload secondary to superior vena cava syndrome;
6. tension pneumothorax
   
   • (the pleural space may be entered unintentionally);
7. air embolism
   
   • (a known complication of mediastinoscopy, occurring when surgical-induced vascular trauma makes possible the venous entrainment of air);
8. perioperative ACE inhibitor use
   
   • (there is an increased risk of significant perioperative hypotension associated with perioperative ACE inhibitor administration);
9. infarction
   
   • (poorly controlled hypertension, decreased preload, vascular disease, autonomic neuropathy); and
10. arrhythmia
    
    • (his poorly controlled blood pressure predisposes him to perioperative arrhythmias).

Question 8

Intra-Operative Management:

The surgeon insists on muscle relaxation.

Shortly after induction, he is advancing the mediastinoscope when the right radial arterial line indicates a blood pressure drop from 145/90 mmHg to 90/65 mmHg.

WHAT WOULD YOU DO?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 8

In managing his hypotension, I would:

1. check the arterial line for accuracy;
2. check the blood pressure in the left arm, recognizing that a difference in pressures between the arms may indicate innominate artery compression;
3. ask the surgeon to rule out massive hemorrhage, innominate artery compression, and compression of other vascular structures;
4. ensure adequate ventilation;
5. look at my ECG tracing to rule out arrhythmia or cardiac ischemia;
6. auscultate the chest for bilateral breath sounds;
7. reduce my volatile agent;
8. quickly review all administered drugs;
9. administer fluids and vasopressors as indicated; and
10. temporarily place the patient in trendelenburg position to improve preload, recognizing that this could exacerbate the venous congestion associated with SVC syndrome.

If these interventions failed to resolve the problem, I would consider –

1. placing a central line in the femoral vein,
2. ordering a bedside ultrasound to better evaluate the patient for pneumothorax,
3. placing a precordial Doppler (sporadic roaring sounds would be consistent with air embolism), and
4. employing echocardiography to better evaluate cardiac function.

Question 9

Intra-Operative Management:

In managing his hypotension, would you consider utilizing nitrous oxide to allow for a reduction in volatile agent?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 9

While nitrous oxide would potentially allow for a reduction in the amount of volatile agent employed to maintain adequate depth of anesthesia (and thus reduce the degree of cardiovascular depression),

I would NOT use it for this case due to the risk of expanding an unrecognized pneumothorax or venous air embolism (spontaneous ventilation increases the risk of venous air embolism during mediastinoscopy).

Pneumothorax may occur when the pleural space is unintentionally entered during the procedure.

It is because of this known complication that a chest x-ray is required prior to discharge for patients who have undergone mediastinoscopy.

Question 10

Intra-Operative Management:

The surgeon says there is bleeding. Now, what will you do?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 10

In the case of hemorrhage, I would:

1. ask the surgeon to discontinue the surgery and pack the wound with surgical sponges,
2. call for help,
3. ensure adequate large-bore access in the lower extremities
   
   • (if the hemorrhage is resulting from a tear in the superior vena cava, medications and fluids utilized in resuscitation would be lost in the mediastinum),
4. initiate resuscitation with fluids and vasopressors,
5. have cross-matched blood brought to the operating room,
6. prepare for massive blood transfusion by notifying the blood bank and ensuring the presence of blood warmers, cell saver, and rapid infusers,
7. place a double-lumen tube or bronchial blocker if the surgeon believes a thoracotomy may be required,
8. place a precordial Doppler, recognizing that there is an increased risk for venous air embolism in the setting of vascular injury, and
9. convert to sternotomy or thoracotomy as necessary.

While deliberate hypotension and reverse-trendelenburg positioning are sometimes used to reduce bleeding and improve surgical visualization in this setting,

I would NOT employ these techniques in this case due to –

• the patient’s symptomatic cerebrovascular disease,
• potentially reduced preload (SVC syndrome),
• poorly controlled hypertension (rightward-shifting of the cerebral autoregulation curve), and
• possible autonomic neuropathy (may be unable to compensate for a change from supine to a head-up position).

Question 11

Intra-Operative Management:

The patient requires sternotomy and repair of a tear in his superior vena cava.

Would you extubate him immediately following the case?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 11

Given the increased risk of postoperative respiratory complications associated with LES (i.e. respiratory muscle weakness and residual neuromuscular blockade), superior vena caval obstruction (airway edema resulting from caval obstruction and possibly exacerbated by aggressive fluid resuscitation), and aggressive fluid resuscitation (in response to his caval tear),

I would leave the patient intubated and maintain mechanical ventilation during the immediate postoperative period.

I would delay extubation until any major fluid shifts had resolved and the patient demonstrated adequate ventilatory function.

Clinical Note:

• Patients can be extubated following mediastinoscopy and discharged on the same day after a chest x-ray is performed to rule out pneumothorax.
• However, this patient is at increased risk for post-operative respiratory complications.

Question 12

Post-Operative Management:

Postoperatively, he is extubated in the ICU and immediately becomes dyspneic.

What do you think may be going on?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 12

His stridor could be caused by:

1. laryngospasm, occurring secondary to superior vena cava syndrome or recent extubation. It could also be a result of:
2. an expanding hematoma,
3. significant airway edema (secondary to superior vena cava syndrome and/or aggressive fluid resuscitation),
4. recurrent laryngeal nerve injury (resulting in obstruction due to unopposed tension of the vocal cords by the cricothyroid muscle),
5. incomplete muscle relaxant reversal (patients with LES are more sensitive to nondepolarizers and reversal of neuromuscular blockade is often less effective),
6. an impaired ventilatory response to hypoxia and hypercapnia secondary to autonomic neuropathy (these patients are more susceptible to drug-induced respiratory depression), or
7. an allergic reaction.

• Clinical Note:*
• If worsening SVC obstruction is suspected during a case, steroids and diuretics may help.

Question 13

Post-Operative Management:

You visualize the vocal cords and note that they are not moving and are in the midline position.

What will you do?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 13

This is consistent with bilateral partial recurrent laryngeal nerve injury (injury affecting only the abductor fibers of the nerve), a known complication associated with mediastinoscopy.

If the airway obstruction were resulting in inadequate ventilation,

I would place an endotracheal tube and provide oxygen, positive pressure ventilation, and sedation as necessary.

I would then alert the surgeon and consult an otolaryngologist.

Clinical Note:

• Complications associated with mediastinoscopy include:
  
  1. tracheal compression or laceration,
  2. cerebrovascular events (secondary to innominate artery compression),
  3. right upper limb ischemia (also secondary to innominate artery compression),
  4. compression of the aorta leading to reflex bradycardia,
  5. pneumothorax,
  6. recurrent laryngeal or phrenic nerve injury,
  7. venous air embolism,
  8. mediastinal hemorrhage, and
  9. esophageal tear.

Question 14

Post-Operative Management:

You go by the ICU to see the patient later that evening and are just getting ready to leave when his pressure acutely drops from 140/88 mmHg to 75/38 mmHg.

What are you going to do?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 14

I would –

1. auscultate the chest,
2. check the ventilator settings,
3. ensure adequate oxygenation,
4. place the patient in trendelenburg position, and
5. administer fluids, vasoconstrictors, and inotropes as indicated.

Since the patient suffered at tear of the superior vena cava during the procedure, my differential would include massive hemorrhage or cardiac tamponade.

While attempting to identify the cause of his hemodynamic instability, I would –

1. ensure adequate intravenous access,
2. order an echocardiogram,
3. call for a surgeon, and
4. consider placing a central line.

Question 15

Post-Operative Management:

On exam you hear muffled heart sounds and notice jugular venous distension.

The blood prssure is now 52/31 mmHg.

What are you going to do?

• (A 62-year-old male with suspected lung cancer presents for mediastinoscopy for staging and diagnosis after sputum cytology and needle biopsy failed to provide a definitive diagnosis.*
• PMH: The patient says he has been smoking for over 40 years. Although he has had a cough for a long time, he became alarmed after coughing up blood 2 weeks ago. His medical history is significant for carotid artery disease with a 60% occlusion of the left carotid artery, and he had a transient ischemic attack 2 months ago, but the vascular surgeon has delayed surgical intervention until the patient’s suspected lung cancer is in remission. He says that he was diagnosed with hypertension two years ago, takes his blood pressure medicine occasionally, and often has high blood pressures at the doctor’s office. Finally, in the last 6 months he has been diagnosed with Lambert-Eaton myasthenic syndrome, and developed orthostatic hypotension, constipation, worsening cough, and increased shortness of breath.*
• Medications: Lisinopril, Hydrochlorothiazide, 3,4-diaminopyridine, and Azathioprine*
• PE: VS: P = 87; BP = 175/103; R = 10; T = 36.6 °C*
• Neck: Bruit heard over left carotid artery; jugular venous distention*
• Airway: Mallampati II*
• CV: RRR*
• Lungs: Clear to auscultation bilaterally*
• CT: Mediastinal mass; no tracheal compression or deviation noted; no apparent compression of the heart or great vessels; opacification of upper extremity collateral veins.*
• Lab: Na+ = 129 mEq/L)*

Answer 15

While the jugular venous distention was already present due to the obstruction of his superior vena cava,

the combination of this finding along with muffled heart sounds is consistent with cardiac tamponade and, if the diagnosis cannot be quickly confirmed by echo, should be treated as such.

Since the patient is intubated and sedated, the chest could be reopened in the intensive care unit, waiting to provide additional anesthesia until the pericardial constriction is relieved and the patient is more stable.

If the surgeon is not available, a pericardiocentesis should be performed to at least temporarily relieve the increasing pericardial pressure, improve diastolic filling, and improve cardiac output.

Once the chest is opened, the tamponade is relieved, and the patient is stable, I would administer anesthetic agents that preserve sympathetic tone (e.g. ketamine) while definitive surgical repair occurs.