Anatomy & Embryology
At how many weeks does surfactant production start, and at what point is surfactant production adequate for independent breathing?
28 weeks and 34 weeks, respectively
This is because CO = HR x SV. Inotropy increases SV, increasing CO. Volume increase will increase venous return and increase SV (t/f increasing CO) as well as RAP. Independently, these have no impact on each other. Increasing TPR decreases inotropy, venous return, and CO without changing RAP. This makes sense, because increased resistance of arterioles makes it harder for blood to flow through the arterial system to the capillaries and through to the venous system. This also increases the amount of pressure that the heart has to overcome to pump blood out.
What are the three options for treating outpatient bacterial pneumonia?
amoxicillin, macrolide (azithromycin or clarithromycin), doxycycline
Why is proper nutrition so difficult to maintain in patients with COPD and other chronic respiratory diseases?
COPD and chronic respiratory disease lead to shortness of breath and decreased appetite, especially with how exhausting eating can be with such poor oxygen levels. This leads to weight loss, as well as loss of muscle strength over time. It can be difficult for these patients to feel ready to exercise.
What is the FEV1/FVC ratio in obstructive lung disease?
Bonus 100 points: What about restrictive?
< 0.7 (70%); restrictive FEV1/FVC is normal due to proportional decreases
What is the most common cause of infective endocarditis?
Staphylococcus
What happens to the V/Q ratio as a result of a pulmonary embolism?
A PE would cause a disruption in blood flow. This would decrease Q, and therefore increase the V/Q ratio.
What is the function of the posterior cricoarytenoid muscle?
pivot the vocal cords laterally, i.e. abduct the vocal cords to let air out of the respiratory tract while breathing.
A 57 year-old patient with COPD comes into clinic complaining of new symptoms after having started a new medication for COPD maintenance. The patient has recently been experiencing bitter taste, dry mouth, and throat irritation. Which drug must this patient be taking?
Bonus 100 points: What is the mechanism of action of this drug?
Tiotropium & Ipratropium.
These are SAMAs and LAMAs, respectively. They are antimuscarinics that bind the M3 receptor to block ACh binding. When the receptor is blocked, cGMP decreases and smooth muscle contraction is decreased, allowing for bronchodilation.
What type of epithelium is present in the terminal bronchioles, and what are the surfactant-producing cells of this area called?
clara cells; ciliated simple columnar epithelium → becomes simple cuboidal
What is the most common form of emphysema, and what area(s) of the acinus does it impact?
Centriacinar; heavily a/w smoking; most common/pronounced in upper lobes
What are the JONES criteria, and what are they indicative of?
Acute rheumatic fever!
Joints (arthritis)
O → heart (pancarditis)
Nodules
Erythema marginatum
Sydenham’s chorea
What acid-base disturbance would be expected at high altitude? Include pH, CO2 level, and bicarb level.
Bonus 100 points: Why??
One would expect to see a respiratory alkalosis.
This is because there is less oxygen in the atmosphere and we breathe faster to oxygenate better. This breathes off more CO2 (low CO2), leading to an alkalosis that originates in the lungs. Le chatelier's principle dictates that more H+ and bicarb will try to compensate for this loss via the blood buffer, leading to a corrective decrease in bicarb (low bicarb) and decrease in H+ ions (alkalosis).
A 5 year-old patient presents with a midline mass in the neck. It is painless, but it elevates with tongue protrusion and moves with swallowing. What did the tissue that makes up the mass originate?
Bonus 100 points: What structure(s) do/does the third pharyngeal pouch become?
1st pharyngeal pouch
2nd pharyngeal cleft
3rd pharyngeal arch
3rd pharyngeal pouch
Tongue
4th pharyngeal pouch
4th pharyngeal arch
E, originates in the tongue
Becomes the thymus and the inferior parathyroid glands
A 35 year-old female presents to your emergency department with dyspnea, poor oxygenation and hypotension. CXR reveals lobar pneumonia. The patient is admitted and begins to improve with supportive care, but will also require antibiotic treatment. Sputum culture demonstrates methicillin sensitive strains. What is the appropriate treatment for nonsevere, inpatient, community-acquired pneumonia?
Azithromycin only
Doxycycline only
Levofloxacin only
Ciprofloxacin only
Azithromycin + levofloxacin
piperacillin/tazobactam + gentamicin + vancomycin
C, levofloxacin only. CAP treated OP can be treated with amoxicillin, macrolides, or doxycycline (though amoxicillin won’t cover atypicals). Nonsevere, inpatient CAP can be treated with a respiratory fluoroquinolone (not cipro) or a combo of beta-lactam plus a macrolide. Severe, inpatient CAP can be treated with a beta-lactam plus [either azithromycin or a respiratory fluoroquinolone]. Nosocomial pneumonia is treated with a PSA-covering agent like P/T, cefepime, etc. plus [an aminoglycoside, resp fluoroquinolone, or aztreonam] plus [vancomycin or linezolid].
A 7 year-old male patient presents to the emergency department with acute-onset respiratory distress one evening. The grandparent expresses that the child has been sick for the past few days, but is just now experiencing a great deal of distress. The patient is in tripod position with notable retractions and inspiratory stridor. A ‘barking’ cough is noted. Which of the following is true of the most likely pathogen?
Cough, coryza & conjunctivitis; negative sense
Gram negative; epiglottitis
Gram positive; sepsis
Negative sense; steeple sign
Positive sense; meningitis
DNA virus; pharyngitis
D; this is a classic case of parainfluenza, which is a negative sense virus in the paramyxoviridae family. It classically presents with steeple sign on CXR.
Your patient has had insidious onset of dyspnea for 2 years. Pulmonary exam shows normal FEV1/FVC ratio. CXR shows hilar and mediastinal lymphadenopathy with sparse calcification and high serum calcium levels. Skin exam is notable for erythema nodosum. Eye exam is notable for uveitis. What might you expect to find upon biopsy of the lymph nodes?
Caseating granulomas
Eosinophilia and lymphocytosis
Abnormal lamellar bodies
Asteroid and Schaumann bodies
Ferruginous bodies and dense collagen banding
D; sarcoidosis has non-caseating granulomas, asteroid bodies, and schaumann bodies.
A 38 year-old male presents to your outpatient clinic due to 6 months of episodic erythema, flushing, diarrhea, and shortness of breath. CXR identifies a lung mass, and biopsy is performed. Which of the following, if found, would be most helpful in confirming the diagnosis?
C-KIT mutation
MYCN mutation
Squamous keratin pearls
Zellballen appearance
Positive mucicarmine stain
Bonus 100 points: What is one of the two paraneoplastic syndromes commonly associated with this type of lung cancer?
D; this is a carcinoid tumor, which is a type of small cell lung cancer. Carcinoid tumors have a zellballen appearance.
The two possible paraneoplastic syndromes for small cell lung cancers (that you have learned this far) are ADH- and ACTH-secreting tumors.
A patient enrolls in a research study investigating the physiology of respiration. The patient is instructed to move as much air as they can during the phase of the respiratory cycle where the diaphragm relaxes. Which of the following details the nervous system pathway utilized to follow the researcher’s instructions?
Intermediate VRG → caudal VRG → spinal cord → muscles of expiration
Rostral VRG → caudal VRG → spinal cord → muscles of expiration
Caudal VRG → rostral VRG → spinal cord → muscles of expiration
CN IX → NTS of DRG → intermediate VRG
CNX → NTS of DRG → phrenic n.
CN X → caudal VRG → spinal cord → muscles of expiration
Bonus 100 points: How heavy are Dr. Wright’s dumbbells?
B. The intermediate VRG and DRG are involved in inspiration. The rostral and caudal VRG are involved in expiration when there is greater respiratory drive. The rostral VRG has interneurons that drive expiration, and the caudal VRG houses the premotor neurons that travel in the spinal cord.
They are 8 pound dumbbells!
A 65 year-old male patient with a history of lung cancer is scheduled to have both the tumor and a few enlarged anterior cervical lymph nodes removed. Both the tumor and lymph nodes for removal are on the left side. Two days later, the patient presents with dyspnea. CXR reveals pleural effusion. What structure was most likely injured?
The patient has a chylothorax due to perforation of the thoracic duct. The thoracic duct travels through the mediastinum on the left and drains into the venous system between the left subclavian vein and left internal jugular vein. It kind of wraps up and behind the jugular.
A patient with idiopathic pulmonary fibrosis presents to your outpatient clinic and wishes to start a medication that will slow the progression of her disease. You would like to start her on a tyrosine kinase inhibitor. Before prescribing this medication, what two contraindications must be considered?
This is nintedanib. Nintedanib has contraindications of moderate to severe liver dysfunction and pregnancy.
A 31 year-old female presents to the emergency department in active labor. She has not received prenatal care. The parent has a history of diabetes and primary hypertension. She does not drink or use illicit substances. The baby is in acute respiratory distress, and lung sounds are absent on the left and severely diminished on the right. Unfortunately, the baby subsequently dies. Exam is also notable for flat nasal bridge, low set ears, bowed legs and clubbed feet. Presentation is consistent with oligohydramnios. What is the likely origin of the pulmonary symptoms? Half points for a partially correct answer.
Oligohydramnios and potter sequence are frequently due to renal agenesis. Renal agenesis is frequently due to placental malperfusion from maternal diabetes and maternal hypertension. The developing fetus prioritizes the brain and heart, leaving the kidneys underperfused. The lack of amniotic fluid production leads to failed expansion of lungs.
A 47 year old male presents to your outpatient clinic with persistent cough w/ sputum production for 4 months. He recalls this happening last spring as well. The patient reports a 30 pack-year history of smoking. He does not use alcohol or illicit substances. His fingers are clubbed and dusky in appearance. BP 131/82, HR 77, RR 20, SpO2 92%. FEV1/FVC ratio is 0.5. What is the Reid index, and what Reid index level might be expected on biopsy of this patient’s lungs?
Reid index is ratio thickness gland layer to thickness wall btw
A 55 year-old female presents with fever, fatigue, progressive shortness of breath, and a 20 pound weight loss over 8 months. The patient has a 35 pack-year smoking history. CXR reveals a peripheral lung mass in the apex of the left lung. Biopsy stains positively for KRAS mutation and mucicarmine stain. What symptom might the patient expect to experience from a paraneoplastic syndrome that characteristic of this type of lung cancer?
This is your classic adenocarcinoma, which is a type of non-small cell lung cancer. These characteristics are also often attributed to squamous cell carcinoma–another type of non-small cell lung cancer. Pancoast tumor is usually associated with non-small cell carcinoma. This patient will experience shoulder pain in the ulnar distribution with typical C8-T2 involvement.
A 26 year-old female presents to the clinic with a year of progressive shortness of breath and dry cough. The patient cannot walk around the block anymore without becoming out of breath. The patient also has cyanosis and clubbing. CXR reveals increased interstitial markings more prominent in the bases. What effect will the patient’s most likely ailment have on the volume of gas transferred per unit time?
This patient has idiopathic pulmonary fibrosis. Pulmonary fibrosis increases the thickness of the alveoli and decreases gas exchange. Vx = D*A*deltaP / deltaX. This will increase deltaX and therefore decrease Vx, i.e. the volume of gas transferred per unit time.