Anterior Mediastinal Mass

Question 1

What are causes of SOB with anterior mediastinal mass?

Answer 1

• mass compression airways
• mass compression heart or great vessels
• mass induced V/Q mismatch
• mass induced post-obstructive PNA
• SVC syndrome —> venous obstruction causing engorgement of airways and mucosal edema
• cardiac defecits a/w downs
• myasthenia gravis a/w thymoma (a common anterior mediastinal mass)

Question 2

What are signs and symptoms of having myasthenia gravis

Answer 2

dyspnea 
diplopia (blurred vision) 
ptosis 
dysphagia 
difficulty chewing 
dysarthria 
muscle weakness

Question 3

diagnosis for Myathenia Gravis?

Answer 3

tensilon test = first line = giving edrophonium increases muscle strength (will worsen pt if having cholinergic crisis)
nerve stimulation
antibody immunoassays

Question 4

What’s a common source of MG?

Answer 4

thymoma
one of the most common anterior mediastinal masses
30- 65% of patients with thymoma develop MG

Question 5

What is bulbar sympamotology?

Answer 5

weakness in CNs 5. 7, 9 - 11 
facial weakness 
difficulty chewing 
dysphagia 
dysarthria (difficulty speaking)

Question 6

What’s the pathophys of MG?

Answer 6

autoimmune disorder
destruction of post-synaptic nicotinic ACh receptors

less receptors in NMJ –> muscle weakness

Question 7

What are airway concerns with Down’s Syndrome?

Answer 7

macroglossia 
subglottic stenosis 
micrognathia 
atlanto-axial instability 
bradycardia occurs in 50% of downs patients who get inhalational induction 

could complicate mask ventilation, laryngoscopy, ETT placement

Question 8

would you use anticholinergic drugs in MG?

Answer 8

anticholinergic drugs can increase muscle weakness and bulbar symptomatology

Question 9

What’s the cutoff for atlanto-axial instability?

Answer 9

• anterior atlantodental interval > 4-5mm in lateral view
• H&P
• identify S/S of cord compression (gait abn, clumsiness, fatigue with ambulation, numbness, weakness)

Question 10

what are common paraneoplastic syndromes associated with cancer (mediastinal mass)

Answer 10

• SIADH: produces vasopressin –> hyponatremia, euvolemic
• Cushing’s : increased ACTH or CRH –> low K, alkalosis, HTN, psychosis
• Lambert - Eaton Myasthenic Syndrome: a/w small cell lung cancer, antibodies to pre-junctional voltage gated Ca channels –> less ACh released to motor end-plate
• humoral hypercalcemia –> parathyroid hormone related peptides –> muscle weakness, arrhythmias, N/V, renal failure

Question 11

what is a known complication when doing mediastinoscopy?

Answer 11

innominate artery compression
monitor by having R pulse ox to monitor pleth, have L art line (know it won’t be obstructed if innominate artery compression happens)

Question 12

What are the blood pressure classification ranges?

Answer 12

normal SBP < 120 / < 80
preHTN SBP 120 - 139 / 80 - 89
stage 1 HTN SBP 140 - 159 / 90 - 99
stage 2 HTN SBP > 160 / DBP > 100