Anesthesiology

Resection of Mediastinal Mass

What the Anesthesiologist Should Know before the Operative Procedure

The anesthesiologist should know about the exact location and extent of the mediastinal mass, its effect on adjacent anatomical structures, as well as its potential for hormonal activity. It is also important to know the goals of the planned surgical procedure, may they be diagnostic, curative or palliative.

The mediastinal cavity is defined anatomically by the following structures:

  • anterior: sternum

  • posterior: vertebral column

  • superior: superior thoracic opening

  • inferior: diaphragm

  • lateral: right and left pleura

Figure 1

Figure 1.

Right neck with PAC/introducer and percutaneous SVC cannula in-situ.

The mediastinal cavity is arbitrarily further divided into three regions: antero-superior, middle and posterior. Mediastinal masses are a heterogeneous collection of benign and malignant tumors and they are usually designated as located in the anterior, middle or posterior mediastinum:

Anterior:

  • Thymoma, Thymic cyst, Thymic hyperplasia, Thymic carcinoma

  • Cystic hygroma

  • Thyroid carcinoma

  • Seminoma

  • Mixed germ cell

  • Lymphoma

Middle:

  • Benign adenopathy

  • Cysts

  • Hiatal hernia

  • Cardiac/vascular structure (eg. aneurysm, myxoma, pericardial fluid,...)

  • Lymphoma ( most common adult diagnosis)

  • Metastasis

  • Esophageal mass or cancer

  • Thyroid carcinoma

Posterior:

  • Neurofibroma

  • Schwannoma

  • Chemodectoma

  • Foramen of Bochdalek hernia

  • Neuroblastoma

The most concerning location of a mediastinal mass for an anesthesiologist is in the antero-superior mediastinum as it has the greatest potential for airway and cardiovascular compromise. Extrinsic compression reducing the diameter of the airway or pulmonary vascular trunk can cause hypoxemia, hypotension leading to cardiopulmonary arrest. The patient’s symptoms (positional dyspnea, orthopnea and stridor) should alert the anesthesiologist as to the increased risk of perioperative complications. Triggering factors for hemodynamic imbalance include the induction of general anesthesia, the supine position on the operating table, the administration of muscle relaxants and the initiation of positive-pressure ventilation.

Issues affecting perioperative management

1. SVC Syndrome

a.Venous obstruction caused by tumor compression of the superior vena cava (SVC),

Superior vena cava syndrome has profound implications for perioperative management. The SVC is particularly vulnerable as it has low intravascular pressure, thin vessel walls and is in close proximity to solid structures such as lymph nodes and bronchi. Therefore there is increased risk of thrombus formation, impaired venous drainage from the head and neck, reduced preload of the right ventricle, decreased cardiac output and increased central venous pressure, which in turn causes interstitial edema and retrograde collateral flow. The most common site of compression is the right side (4:1) above the confluence of the azygos vein. Venous congestion can cause severe laryngeal edema, acute airway obstruction and airway difficulties during induction or emergence of anesthesia.

b. In patients with superior vena cava syndrome, the intracranial pressure can rise so much as to cause neurologic symptoms due to the impaired outflow of the upper body. Patients are at increased risk of TIA and CVA. Use of anticoagulation has implications for use of regional anesthesia and intraoperative bleeding.

c. Signs and symptoms: dizziness, syncope (especially supine or with Valsalva maneuver), orthopnea, dyspnea, pallor (with sudden change of body position), plethora of the head and neck, prominent cutaneous venous congestion, papilledema, periorbital edema, breast edema (similar to gynecomastia), laryngeal edema (inspiratory stridor, dyspnea), jugular/arm/thoracic venous dilatation (absent venous collapse upon lifting of the arm above the level of the heart), or neurologic symptoms (headache, mental status changes, nausea, vomiting, neurologic deficits).

d. Perioperative considerations: place intravenous access in femoral vein or lower extremity, consider positioning as a factor that will exacerbate airway edema and bleeding.

2. Compression of the tracheal or bronchial airways

a. Mass-related airway collapse can occur at any moment of the peri-operative period. A mediastinal mass is more likely to have a compressive effect on the small, flexible airway structures and chest cavity of children.

b. Children are more susceptible to perioperative complications related to anatomy, types of tumors and symptomatology. Smaller airways and lack of reserve contribute to the increased risk. A mediastinal mass is more likely to have a compressive effect on the small and flexible airway structures and chest cavity of children. After induction of anesthesia, spontaneous ventilation should be continued whenever possible, avoiding muscle relaxation and positive-pressure ventilation (especially in symptomatic children in which respiratory issues can be anticipated).

c. Signs and symptoms: cyanosis (especially supine), dizziness, syncope (especially supine or with Valsalva maneuver), orthopnea, dyspnea, pallor (with sudden change of body position), laryngeal edema (inspiratory stridor, dyspnea), hoarseness, headache, mental or status changes.

d. Postoperative respiratory complications are related to the degree of tracheal compression as noted on CT scan.

3. Cardiovascular compromise

a. Risk of perioperative cardiac complications has been related to presence of pericardial effusions and compression of pulmonary artery.

b. Signs and symptoms:chest pain, cyanosis (especially supine), dizziness, syncope (especially supine or with Valsalva maneuver), orthopnea, dyspnea, pallor (with sudden change of body position), pulsus paradoxus, blood pressure fluctuations, edema of face/neck/chest/limb, hypotension or cardiac arrest.

4. Associated Morbidities

a. Patients having a Thymoma are often associated with Myasthenia gravis. In some cases, thymectomy can provide temporary improvement of symptoms. It is important to avoid or limit the use neuromuscular blockers and continue preoperative pyridostigmine (Mestinon) for controlling symptoms (see musculoskeletal comorbidities below for more details).

b. Lymphoma: the most common adult mediastinal tumor. Symptoms include: fever, night sweats, weight loss, and dyspnea.

1. What is the urgency of the surgery?

What is the risk of delay in order to obtain additional preoperative information?

The risk of delaying surgery in order to obtain additional preoperative information must balance the possible incremental benefit against the risk of acute event or worsening symptoms.

i. Emergent- The patient is showing obvious signs of airway obstruction, cardiovascular collapse or impending distress directly related to the mediastinal mass.

ii.Urgent- The patient is becoming increasingly symptomatic or is requiring increasing support in terms of cardiovascular or respiratory decompensation. Also, the mass may become increasingly difficult or impossible to resect surgically if allowed to grow any further

iii.Elective- The patient is coping well or is asymptomatic but the mass has a negative impact on quality of life. The mass may be manageable with other treatments prior to surgical resection including medical, radiation and/or chemotherapy

Controversy over empiric therapy

1. Some clinicians have advocated the patients at high risk of airway obstruction or hemodynamic compromise could benefit from pretreatment with steroids, empiric chemotherapy and or radiation.

2. Except in extreme circumstances, a tissue diagnosis is much preferred before initiating any preoperative therapy.

2. Preoperative evaluation

Depending on the patient age, the nature and location of the mass as well as presence or absence of symptoms, the associated co-morbidities will vary greatly.

Cancer patients should be evaluated for the 4 "M":

  • Mass effect (eg. compression of tracheobronchial tree, pulmonary artery, SVC or esophagus, obstructive pneumonia, lung abscess, pancoast syndrome, recurrent laryngeal nerve or phrenic nerve paresis),

  • Metabolic abnormalities (eg. Lambert-Eaton syndrome, hypercalcemia, hyponatremia, Cushing syndrome , Myasthenia Gravis)

  • Metastases (eg. to brain, bone, liver and adrenal)

  • Medications (eg. bleomycin, mitomycin C, doxorubicin, cisplatin...)

3. What are the implications of co-existing disease on perioperative care?

Medically unstable conditions warranting further evaluation and optimization include esophageal obstruction include COPD, DM, CRI, CAD and recent CVA, as in any other surgical procedure.

Delaying surgery may be indicated if: the additional preoperative testing changes anesthetic management or the pre-operative optimization will improve the post-operative course.

Some of the surgical patients have undergone chemotherapy; the thorough history of chemotherapeutic agents administered and assessment of end organ dysfunction is important.

  • Patients having a history of receiving Adriamycin, Daunorubicin, or Doxorubicin, all of which cause potential cardiac toxicity, need an assessment of cardiac function (echocardiogram).

  • Bleomycin is associated with pulmonary toxicity resulting in pulmonary fibrosis and can exacerbate oxygen induced lung toxicity.

a. Cardiovascular system

Cardiac complications represent the second most common cause of perioperative morbidity and mortality of the thoracic surgical population.

Perioperative evaluation:

  • Comorbid cardiovascular ischemia: Beyond the standard cardiac evaluation, noninvasive testing is indicated for patients having major (unstable ischemia, recent infarction, severe valvular disease, significant arrhythmia) or intermediate (stable angina, remote infarction, previous congestive failure or diabetes) clinical predictors of myocardial risk. Therapeutic interventions must be considered on a case by case basis balancing the benefit and the urgency of the surgery.

  • Comorbid arrhythmia: Several factors correlate with an increased incidence of perioperative arrhythmias: extent of resection, intrapericardial dissection, intraoperative blood loss, age of the patient and increased sympathetic stimuli related to pain.

Anesthetic precautions and risk reduction strategies:

  • The use of prophylactic beta-blockers reduces the risk of perioperative risk of arrhythmias and ischemia in surgical patients with known or suspected coronary artery disease.

  • Plan for thoracic epidural analgesia as it was shown to decrease incidence and severity of arrhythmias.

b. Pulmonary

Respiratory complications are a major concern. Risk associated with pre-existing pulmonary disease would further increase the risk of morbidity and mortality related to the mediastinal mass.

Perioperative evaluation:

  • Patient having chronic pulmonary disease should be should be evaluated to optimize medical and bronchodilator therapies.

  • Postoperative analgesia should be discussed with both the surgeon and the patient.

Anesthetic precautions and risk reduction strategies:

  • A perioperative program of intensive chest physiotherapy for patients with COPD should be instituted to help decrease postoperative pulmonary complications (eg cough and deep breathing, incentive spirometry, PEEP, CPAP).

  • Smoking cessation should be encouraged: postoperative carboxyhemoglobin concentrations decrease if smoking is stopped more than 12hrs, pulmonary complications are decreased if smoking is stopped for more than 4 weeks.

  • Use local or regional techniques whenever possible with anterior mediastinal masses in particular.

c. Renal

A pre-existing renal insufficiency may worsen post-operatively (acute on chronic).

Signs and symptoms:

Fluid retention, cardiac arrhythmias (from electrolyte imbalance).

Perioperative evaluation:

  • Physical exam: evaluate the patient for signs of edema, neurologic symptoms and arrhythmias.

  • History of previous chemotherapy treatment (ie. , cisplatin) may increase the risk of postoperative renal dysfunction.

  • Laboratory date: measure creatinine, blood urea nitrogen and potassium pre-operatively for baseline values.

Anesthetic precautions and risk reduction strategies:

  • Avoid nonsteroidal anti-inflammatory medications in patients having renal insufficiency.

  • Careful fluid administration.

  • In patient having significant renal dysfunction, avoid medications that require preserved renal function for elimination (eg morphine)

d. Gastrointestinal

Signs and symptoms of esophageal obstruction:

Dysphagia, GERD, failure to thrive or weight loss, regurgitation of undigested food, chest pain

Perioperative evaluation:

  • does the patient present with active signs of GERD or obstruction?

  • is the patient taking any medications to treat GERD?

Anesthetic precautions and risk reduction strategies:

  • GERD prophylaxis

  • Consider induction of general anesthesia using cricoid pressure

e. Neurologic:

The patient may have pre-existing neurological symptoms with an etiology unrelated to the mediastinal mass or may exhibit neuropathies as part of a paraneoplastic syndrome or metastatic disease.

Signs and symptoms:

Depending on the location and etiology of the neurological issue, signs and symptoms may vary greatly.

Perioperative evaluation:

  • Perform a full neurologic exam and record any unusual findings pre-operatively.

f. Endocrine:

The mediastinal mass may in some cases secrete endocrine or endocrine-like substances.

Signs and symptoms:

  • Secretion of adrenocorticotropic hormone can cause Cushing syndrome

  • Secretion of parathormone can cause hypercalcemia

  • Secretion of antidiuretic hormone may cause hyponatremia and SIADH

  • Carcinoid

  • Others: ectopic gonadotropic secretion, hypoglycemia,...

Perioperative evaluation:

  • Evaluate for metabolic abnormalities and potential systemic involvement.

Anesthetic precautions and risk reduction strategies:

  • Correct electrolyte abnormalities pre-operatively

h. Musculoskeletal

Signs and symptoms:

  • Rare, usually related to pre-existing co-morbidities (eg Myasthenia gravis) or pain (eg associated with bone metastasis) or weakness resulting from neurological involvement (eg previous CVA or SVC syndrome with cerebral edema). Short-term immunotherapy with transient improvement of symptoms but increased risks of infection, hypotension and PE (plasmapheresis and immunoglobulins)

  • Myasthenia gravis

    • Signs and symptoms:

      • Ptosis and diplopia

      • bulbar muscle weakness (pharyngeal and laryngeal muscles) causing high risk for pulmonary aspiration of gastric content.

      • skeletal muscle showing increasing weakness with exercise.

    • Precipitating factors: infections, electrolyte abnormalities, pregnancy, emotional stress, surgery and certain antibiotics (eg aminoglycosides).

    • Medical management:

      • cholinesterase inhibitors (eg pyridostigmine) although high doses can increase skeletal muscle weakness (“cholinergic crisis”)

      • immunosuppressants (corticosteroids, azathioprine, cyclosporine)

      • short-term immunotherapy with transient improvement of symptoms but increased risks of infection, hypotension and PE (plasmapheresis and immunoglobulins)

Perioperative evaluation:

  • Thymomas are associated with Myasthenia gravis. In some cases, thymectomy can provide temporary improvement of symptoms or induce remission. The mechanism by which a thymectomy improves clinical symptoms is uncertain but it has been shown to decrease the levels of acetylcholine receptor antibodies in the postoperative period.

  • Preoperative period: optimize patient strength (especially the respiratory function)

    • continue anti-cholinesterase treatment perioperatively,

    • avoid immunosuppression which increases the risk of infection and

    • perform plasmapheresis if the vital capacity is less than 2 liters

  • Intraoperative period: a median sternotomy allows the removal of all thymic tissue but a cervical mediastinoscopy allows for a smaller incision and therefore less postoperative pain.

  • Neuraxial analgesia decreases postoperative pain and therefore enhances postoperative breathing.

Anesthetic precautions and risk reduction strategies:

  • Preoperative period: use opioids with caution as patients often require postoperative ventilation support (criteria that correlate with increased likelihood of for controlled ventilation postoperatively include a duration of the disease for more than six years, the presence of COPD unrelated to MG, daily doses of pyridostigmine exceeding 750mg and a preoperative vital capacity below 2.9 liters)

  • Muscle relaxants:

    • antibodies decrease the number of functional acetylcholine receptors which increases their sensitivity to non-depolarizing muscle relaxants (therefore, titrate dose while monitoring train-of-four)

    • pyridostigmine also inhibits the plasma cholinesterase which can increase the sensitivity to succinylcholine and

    • corticosteroids may produce resistance to non-depolarizing muscle blocking effects of steroidal muscle relaxants such as vecuronium

  • Induction often does not require muscle relaxation, especially if using volatile anesthetics.

  • Maintenance: Volatile anesthetics may decrease or eliminate the necessity for muscle relaxants and opioids may have prolonged effects, especially on ventilation.

  • Postoperative period: leave the endotracheal tube in place until the patient demonstrates an ability to MAINTAIN adequate levels of ventilation as skeletal muscle strength may initially seem adequate in early stages after anesthesia and surgery, only to deteriorate a few hours later. It is therefore important to anticipate the need to support ventilation during the postoperative period.

4. What are the patient's medications and how should they be managed in the perioperative period?

a. What should be recommended with regard to continuation of medications taken chronically?

i. Cardiac: continue all cardiac medications especially beta-blocker therapy. Some clinicians would advocate for discontinuing diuretic therapy and ACE inhibitors.

ii.Pulmonary: continue bronchodilator therapy as well as steroids during the perioperative period.

iii. Renal: no changes.

iv. Neurologic: continue regular neurologic medication regimen and take into account any interactions with anesthesia medications (eg. phenytoin may increase neuromuscular blocking agent requirement)

v. Anti-platelet: evaluate risks versus benefits of interrupting anti-platelet therapy in time to allow for neuraxial anesthesia (eg stop clopidogrel 7-10 days prior to epidural placement)

vi. Psychiatric: continue all psychiatric medications.

b. How To modify care for patients with known allergies

Avoid all medications to which the patient has a known allergy.

c. Latex allergy

If the patient has a sensitivity to latex (eg. rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.

5. What laboratory tests should be obtained and has everything been reviewed?

Common laboratory normal values will be same for all procedures, with a difference by age and gender. Some laboratory tests that are performed on all preoperative patients are especially relevant to the evaluation of a patient with a mediastinal mass.

Some laboratory tests that are performed on all preoperative patients are especially relevant to the evaluation of a patient with a mediastinal mass.

a. Hemoglobin levels: Depending on the patient's age, cardiovascular and respiratory co-morbidities, the patient's tolerance for anemia may vary.

b. CBC: leukocytosis may indicate active infection (pulmonary or other).

c. Electrolytes: Obtain a full metabolic panel with particular emphasis on potassium, calcium, BUN and creatinine levels.

d. Coagulation panel: A bleeding diathesis is especially important in patients having a SVC syndrome or if neuraxial blocks are considered.

e. Chest x-ray: At a minimum, the anesthesiologist should look at a patient's chest x-ray to evaluate the location of the mediastinal mass and its relationship to other anatomical structures.

f. CT scan of the chest is often helpful, especially is there is concern for tracheobronchial or vascular compression). Such a study will provide information as to the location and relative risk of pulmonary or cardiac complication. CT scan of neck and thorax will permit:

a. Assessment of difficulty of lung isolation

b. Assessment of risk of hypoxemia during one lung ventilation

c. Evaluation of difficulty of endotracheal/endobronchial intubation (eg due to previous radiotherapy, infection, pulmonary or airway surgery, mass effect…)

g.CT scan of the head or a neurology consult may be considered for documentation of possible pre-existing deficits (eg. prior CVA).

h.Cardiovascular system evaluation: ECG, echocardiography, Cardiac ultrasound can diagnose pericardial effusions, vascular compromise and cardiac dysfunction teat may reflect the extent of the cardiovascular system involvement (eg. extent of SVC obstruction, compression of the heart or extent of deep venous thrombosis in the upper body). Compression of cardiac and vascular structures can impede diastolic filling resulting in systemic hypotension.

i. Other tests: Flow Volume Loops are commonly ordered, but have poor correlation with the degree of airway obstruction and perioperative complications. Request additional laboratory data if the mediastinal mass is suspected to have hormonal activity (eg. measure a TSH level if this is a thyroid carcinoma).

Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?

Depending on the patient's history and physical examination (see preoperative evaluation for optimization) as well as the type of procedure planned, the anesthetic management will change dramatically. Always discuss exact surgical procedure extent and goals preoperatively with the surgeon as well as post-operative pain management options with the patient.

Types of procedures in the mediastinal cavity:

  • Cervical mediastinoscopy

  • Medial sternotomy and resection

  • Anterior mediastinoscopy

  • Thoracotomy and resection

  • Thoracoscopy

  • VATS - Video assisted thoracic surgery

  • Cervical mediastinal exploration

  • Extrathoracic lymph node biopsy

  • Upper GI endoscopy (diagnostic vs. esophageal stent placement)

  • Bronchoscopy (diagnostic vs. endobronchial stent placement vs. laser debulking)

a. Regional anesthesia

  1. Neuraxial

    1. Benefits: thoracic epidural analgesia is the current gold standard for post-thoracotomy analgesia.

      • Provides excellent post-operative pain management if the surgical incision is included in the area covered (eg. thoracic epidural for thoracotomy)

      • Associated with much improved post-operative respiratory function and accelerated recovery from thoracic procedures

      • Decreased intra-operative anesthetic requirements (less intraoperative narcotics may accelerate post-operative respiratory recovery)

    2. Drawbacks

      • Potential for epidural hematoma (especially in patients with coagulation disorders or who are anti-coagulated for arrhythmias or DVTs in SVC syndrome)

      • Potential for epidural abscess (especially in patients prone to infection)

      • The high block necessary for adequate analgesia when using local anesthetics is associated with systemic hypotension, bradycardia and decreased cardiac output as a result of the consequent sympathectomy. Epidural opioids produce less hypotension but increase the risk of respiratory depression.

  2. Peripheral Nerve Block

    1. Benefits:

      • paravertebral blocks (uni- or bilateral) may replace neuraxial blockade with decreased risk of epidural hematoma (eg in a patient who could not interrupt his anti-platelet therapy).

    2. Drawbacks:

      • requires an experienced anesthesia provider in the regional technique employed

b. General Anesthesia

a. Benefits: Establishing a secure airway that may bridge stenotic or compressed portions of an airway, to enable a preferred surgical approach or intervention (supine positioning for bronchoscopy or mediastinoscopy or lateral decubitus position for thoracotomy). A secure airway also reduces the potential for aspiration in patients who may be more at risk than the general population, especially if there is esophageal compression.

b.Drawbacks: The induction of general anesthesia in the supine position with the use of muscle relaxants and initiation of positive pressure ventilation as well as the turbulent post-stenotic airway flow may lead to:

  • Reduced lung volumes

  • Smooth muscle relaxation leading to increased compression of airways

  • decreased gas exchange

  • increased arterial-venous mismatching,

  • increased shunting formation,

  • impaired expiration,

  • increased airway resistance,

  • compression of the airway related to extrinsic compression

  • hypoxemia.

c. Optimization:

  • Some clinicians advocate awake intubation to preserve spontaneous ventilation.

  • Sitting position during induction of anesthesia until secure airway is in place,

  • Maintenance of spontaneous ventilation after endotracheal tube placement.

  • Halogenated drugs and Ketamine are preferred for their bronchodilating properties and permit administration of 100% oxygen, the use of Dexmedetomidine has also been advocated by some clinicians.

  • A heliox mixture (30% O2 and 70% Helium) may be helpful to lessen airway resistance in turbulent airway flow and therefore improve gas exchange (although at the expense of lower FiO2),

d. In case of intraoperative difficulties; discuss/consider possible rescue strategies preoperatively.

  • Airway compromise is often related to extrinsic compression and may benefit from resumption of spontaneous ventilation or changing position (raise head of bed, lateral decubitus positioning).

  • Airway collapse: consider endobronchial intubation to maintain patency (use of double lumen tube, rigid bronchoscopy) or stent placement. Preoperative CT scan should prepare clinicians as to location of obstruction and success of stenting.

  • In case of hemodynamic compromise, consider compression of the cardiac chambers or the pulmonary artery. Changing position may reduce extrinsic compression and improve blood flow.

  • Use of extracorporeal circulatory support is often mentioned but rarely used (adults rarely require it implementation). The time required for setup and instituting support would make this therapeutic option ineffective for emergent events. Few case reports have mentioned its use for pediatric population.

c. Local anesthesia and Monitored Anesthesia Care

a. Benefits: safest option for the simplest procedures (ie. biopsy for diagnosis).

  • Continuing spontaneous ventilation without the necessity to administer muscle relaxants or institution of positive pressure ventilation markedly reduces the risk of airway compromise.

  • Avoids risks of hemodynamic instability.

b. Drawbacks:

a. Increased risk of aspiration.

b. Limitations in patient positioning related to respiratory or cardiovascular symptoms.

c. Limitation of surgical approach and intervention that may reduce the chance of success.

d. May not be applicable for pediatric patients.

6. What is the author's preferred method of anesthesia technique and why?

  • Communication: discuss the patient, operative approach and contingency plans (rigid bronchoscopy, stent placement, even availability of extracorporeal circulatory support) with surgeon and other operating room staff.

  • In cases of SVC obstruction, venous access should be secured in the lower extremity or femoral vein.

  • Use local or regional techniques whenever possible, especially with symptomatic patients having anterior mediastinal masses.

  • Obtain a good preoperative history playing special attention to severity of symptoms and personally review the CT scan.

  • If general anesthesia is deemed necessary, spontaneous ventilation should be used whenever possible, avoiding muscle relaxation and positive-pressure ventilation (especially in symptomatic children in which respiratory issues can be anticipated).

  • If controlled ventilation is required, consider a slow transition from spontaneous to controlled ventilation and optimize positioning to minimize respiratory or hemodynamic perturbations.

  • In cases of general anesthesia, an arterial line for blood pressure monitoring and sampling would supplement the standard monitoring.

  • If a mediastinoscopy is planned, place an arterial line in the right radial artery to diagnose compression of the innominate artery or hemodynamic instability.

b. If the patient is intubated, are there any special criteria for extubation?

After the surgical procedure is completed, the head of the bed should be raised to facilitate drainage lessening edema. Muscle relaxants should be reversed and spontaneous assisted ventilation should be resumed. If extubation is considered, the anesthesia team should be vigilant and prepared to secure the airway in case of problems post extubation.

Patients should be considered candidates for extubation immediately after the procedure. However, airway edema related to positioning, surgical trauma and SVC syndrome or risk of airway compromise related to tracheomalacia may markedly increase the risk of postoperative respiratory complications. The decision to extubate should be discussed with the surgeon and must take into consideration the following factors: anticipated airway edema, severity of preoperative respiratory symptoms, surgical trauma and if procedure relieved extrinsic tumor compression.

If the patient has a double lumen tube in place but is deemed not to be a candidate for extubation, the tube should be changed for a single lumen endotracheal tube. If bronchial compression is a consideration, tube exchange for a single lumen tube could trigger airway compromise. A current alternative is the option of placing a bronchial or tracheal stent for patients having extrinsic tracheobronchial compression.

c. Postoperative management

  1. What are common postoperative complications, and ways to prevent and treat them?

    • Cardiovascular- Hemorrhage, extrinsic compression of heart or great vessels.

    • Pulmonary- airway edema, airway compression, and pneumothorax,

    • Neurologic- anterior mediastinal tumors may invade phrenic or recurrent laryngeal nerves. Surgical intervention may cause a temporary or permanent injury. Recurrent laryngeal nerve injury, phrenic nerve injury, autonomic reflexes from compression or stretching of the trachea/vagus nerve/great vessels

    • Other- Infection, tumor implantation in the wound, esophageal injury

  2. What analgesic modalities can I implement? Post-operative pain management for thoracotomies will significantly benefit from use a thoracic epidural analgesia, permitting earlier ambulation, tolerating chest physiotherapy (including incentive spirometry). In case of a mediastinoscopy, adequate analgesia can be achieved using intravenous narcotics and infiltrating the site using local anesthetics.

  3. Patient positioning: patient should be kept in a head up position peri-operatively to minimize venous engorgement and to facilitate drainage of edema related to intraoperative management.

  4. Fluid management: the minimize edema by avoiding aggressive fluid resuscitation especially in patients having SVC syndrome.

  5. Pulmonary function: administer supplemental oxygen, raise head of bed, incentive spirometry, bronchodilator therapy.

  6. What level bed acuity is appropriate? The decision must take into consideration preoperative symptoms, extent of surgery, and risk of postoperative respiratory events.

    • floor: low risk patient having no intra-operative complications and patient meets PACU discharge criteria.

    • telemetry: moderate risk patient but had an uneventful operative course.

    • step-down: moderate risk patient having a complicated intra-operative course but has remained cardiovascularly stable.

    • ICU: if the patient remains intubated, is deemed at high risk of respiratory compromise, shows hemodynamic instability, experienced significant intra-operative complications or if the surgery was very extensive and the patient needs close monitoring for at least 24hrs post-operatively.

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