Create
Learn
Share

Pulmonology Quiz 3a

rename
eem8u's version from 2016-11-21 21:16

**** Pulmonary Vascular Disease

Question Answer
mean pulmonary arterial pressure14
mean pulmonary capillary pressure10
mean pulmonary venous pressure8
mean systemic artery pressure93 (120/80)
***V=IR in pulmonary systemPpa-Pla = co x pvr (P difference between pulm artery and left atrium
resistance/compliance in pulmonary vessels (why?)Low R / High C —> less muscle and elastin than systemic
explain capillary recruitment effectcapillaries are collapsed at rest —> dilate with increased blood flow = ****DECREASED resistance (b/c can increase blood volume by at least 3)
memorize

 

****causes of pulmonary hypertension
Question Answer
***defined Ppa of HTN≥ 25 mmHg
calculate PpaPpa = (CO x PVR) + PLa —— (derived from above V=IR)
WHO group 1PAH - including idiopathic, heritable, drug/toxin-induced, **HIV, portal hypertension, congenital heart disease, schistomiasis
WHO group 2Left heart disease
WHO group 3Lung disease (COPD, interstitial, etc) & HYPOXIA (sleep disorder, hypoventilation disorder, high altitude chronic….)
WHO group 4thromboembolic —> causing chronic pulmonary HTN
WHO group 5“other” - *chronic hemolytic anemia / sarcoid / metabolic disorders /tumors /renal failure
memorize

 

PAH (WHO group 1) Pathology
Question Answer
****PAH affects arteries _____ um in diameterMUSCULAR arteries < 500 μm
***4 lesions seen in PAHmedial smooth muscle (tunica media) hypertrophy/ in situ thrombosis / tunica intima thickening AND endothelia cell growth >> PLEXIFORM lesion (separate, but both can lead to obliteration) see 18.12
***endothelin pathway in PAHUP // endothelin > vasoconstriction & smooth muscle proliferation
***nitric oxide pathway in PAHDOWN // L-arginine to L citruline makes NO > increase cGMP > vasodilation & anti proliferation
****prostacyclin pathwayDOWN // arachidonic acid >> prostaglandin I2 >> increase cAMP >> vasodilation & anti proliferation
***germ
line mutation assc w/ heritable PAH (and risk)
BMPR2 — 20% will develop
congenital heart disease pathologyhigh pressure and flow >> endothelial dysfunction
portal hypertension pathologysplanchnic blood bypasses liver >> systemic venous overload
2 most common WHO 1 subgroups1- associative PAH 2- idiopathic IPAH
5 causes of associate PAHCT disorders (including lupus, systemic sclerosis) , congenital, portal hypertension, HIV, schistosomiasis
***leading causes of associated PAHcollagen vascular disease / CT disease
PAH with best and worst survival ratesCongenital-best / worst - HIV and collagen vascular disease
memorize

 

Right ventricular failure in PAH
Question Answer
RV vs LV- free wall2-3mm vs 8-11 mm
RV vs LV- fibersRV lacks circumferential constrictors (LV has more contractile force)
RV vs LV- complianceRV is greater — like floppy ballon
RV vs LV-SV and after load (WHY?)RV is GREATLY Decreased SV w/ increased after load (b/c of system that it pumps into)
define interventricular dependencedilation of RV compromises LV fx >> RAPID decompensation
symptoms of R heart congestionabdominal pain/fullness and peripheral edema (from venous pooling)
symptoms of low CO/perfusiondyspnea/fatigue/ chest pain/ palipitaitons/lighthead / syncope
***PE - heart sounds & cardioRV heave/ split S2/ S3 / S4 /regurigitaiton >>> sounds of R heart failure // JVD and increased venous pressure
PE- vitalshypoxemia, hypotension, tachycardia
PE-peripherycool extremities/ lower edema
***PE-GI(signs of right-sided congestion) = ascites, hepatomegaly, pulsatile liver
**No significant Rales* in pure PAH - WHY?(b/c assc w/ Left-side heart failure/fluid overload, WHO II)
memorize

 

****PAH Diagnosis
Question Answer
mPAP at rest≥ 25 mmHG
pulmonary capillary wedge pressure measures(approx) Left atrium — ballot —> static column of fluid hasta L.atrium
high PCWP (wedge pressure) consistent withWHO II (b/c left-atria high —> Left heart disease)
****PCWP threshholdPCWP > 15 mm Hg — WHO II // PCWP ≤ 15 mm Hg — pre capillary (WHO I/III/IV)
if CO maintains constant, but PVR increases, what happensPAP also increases! Pap = (CO x PVR) + PLA
memorize

 

****PAH treatment
Question Answer
prostanoids - pathway & mechanism prostacyclin pathway > stimulate adenylate cyclase > UP cAMP > vasodilation, antiproliferation, platelet aggregation inhibition **-prost-**
Epoprostenol- mechanism & administration(aka prostacyclin) prostanoid / continuous IV (w/ two IV’s) b/c half life 3-5 mins
Treprostinill- mechanism & administration(prostacyclin analogue) IV/ Sub Q (2-4 hours)
***Selexipag - mechanism & administration(prostacyclin IP AGONIST) **little effect on other Prostanoid receptors*** / oral 2x/day
Endothelin Receptor Antagonist - mechanismgoal - block ETA (and not ETB) / both responsible for vasoconstriction and smooth muscle prolif/ ETB also cellars ET and induces NO/prostacyclin production (This is good)
bosentan - class & administrationendothelin receptor antagonist (22:1 ratio for A>B) , PO
ambrisentan - class & administrationendothelin receptor antagonist (77:1), PO
macitentan - class & administrationendothelin receptor antagonist (50:1), PO
Phosphodiesterase-5 inhibitors- pathway & mechanismNO pathway - inhibit phosphodiesterase specific to cGMP “-afil”
sildenafil - class & administrationPPD-5 inhibitor >> increase cGMP (NO pathway), PO/IV
tadalifil - class & administrationPPD-5 inhibitor (cGMP pathway, increases cGMP) PO
****Riociguat - class & administration(NO pathway) stimulates SOLUBLE GUANYLATE CYCLASE >> more CGMP
4 considerations w/ pulmonary vasodilatorswill also decrease SVR (caution in hypotensive) / rebound PULMONARY HYPERTENSION w/ abrupt withdrawal (esp epoprostenol), **worsen V/Q match > hypoxemia, pulmonary edema
explain risk of pulmonary edema (and when this is a risk)vasodilator > more blood through capillaries > increased capillary pressure > possibility of edema ***In LEFT Heart Disease when PLa is already elevated
***medication w/ SE of liver toxicitybosentan
****medication w/ SE of teratogenERA’s
***medication w/ SE of jaw painprostenoids
only pulmonary medications with proven survival benefitepoprostenol
pulmonary trhmboendarectomy for which WHO group4 (PE clot)
memorize

 

**REVEW 18.31 RV vicious cycle

Pulmonary Thromboembolism

Question Answer
coursemovement of blood clot from systemic vein > heart > pulmonary circulation
___% of hospital deaths attrib to PE5-10%
Virchow’s Triadhypercoagulability (altered coagulability) // STASIS or stagnation // endothelial injury
****factor V Leiden - mutation, mechanism of thrombophiliaArg —> glut / factor Va (of coagulation cascade) resistant to protein C (usually keeps it in check)
****heritable prothrombin - mutation, mechanism of thrombophiliaG20210A, increase prothrombin (thrombin precursor, converts fibrinogen —> fibrin)
***3 anticoagulant deficienciesprotein C / protein S / anti thrombin III
acquired causes of hyper coagulability (name 5)bone fracture, ortho surg, estrogen, AFTER birth, foreign body, cancer (esp brain tumor)
major cause of stasis**prolonged travel!
memorize

 

Hemodynamics & V/Q in PE
Question Answer
2 factors impairing gas exchange1) mechanical obstruction of vessel 2) platelet mediators are BRONCHOconstrctive (serotonin /thromboxane A2)
***normal PAP / PVR with obstruction range ____% (why)< 20% — vessel recruitment & dilation
obstruction of 30-40 % causesincreased PAP and modest RAP( b/c after load up)
obstruction over 50 % causesrapid CO drop and rapid RAP elevation
***in otherwise healthy patients, maximum PAP generated by RV is40 mmHG (greater in patients with chronic RV hypertrophy)
alveolar gas 02/co2 in pure shunt (such as mucous plug)02 - 40 / co2 46 (same as venous blood)
***alveolar gas 02/co2 in pure dead space (such as PE)02 - 150 / co2 - 0 (same as inhaled air)
*** alveolar gas 02/co2 in normal alveolus02- 100 / co2 - 40
***actual co2 levels in increased dead-space ventiatlionHYPOcapnia b/c of compensatory increase in minute ventilation
memorize

 

****hypoxemia in PE
Question Answer
role of dead space**Does NOT cause hypoxemia***
role of PVRincreased perfusion to poorly ventilated areas — low V/Q units
role of COdecreased CO > b/ higher percentage of delivered o2 consumed > lower venous o2 (so blood starts at lower sat)
role of surfactantafter 24 hours of occlusion >> loss >> atelectasis /edema >> hypoxemia *WIth partial thrombus resolution ** (b/c lung collapse)
role (and cause) of bronchoconstrictionplatelet mediators cause - low V/Q (wheezing heard)
memorize

 

clinical PE
Question Answer
***most common symptomcute onset dyspnea — ventilate more to comp for DEAD SPACE
BP changehypotension
lung soundsmaybe normal (b/c this is CV problem) / crackles (due to atelectasis/infarct) / wheeze (if bronchoconstriction)
cardiac soundsindication of Right dilation (RV heave, split S2, loud P2) also TR and PR murmurs, RV s3- sign of R heart failure!
CXR - possible findingsnormal! or Hampton’s hump (w/ infarction), west mark’s sign
review hampton’s humpslide 16
***westmark’s signdecreased vascular marking, cloud indicate clot (crude sign)
***how will a ventilation/perfusion sign show PE (and how to conduct)areas of VENTILATIOn w/o PERFUSION (perfusion- inject albumin / ventilation - inhale xenon radioisotope)
Lower extremity ultrasoundlook for NON-compressed vein >> DVT
positive Dimer test indicates in vivo formation and degration of FIBRIN clot (nonspecific for lungs)
how are D-dimers formedfibrinogen > cleaved by thrombin into fibrin polymers >> cross linked by FACTOR XIIIa >> digestion by plasmin > > fragments include DD dimer (detected by antibodies)
PE causing pulmn HTN is what categoryWHO IV
memorize

 

Treatment
Question Answer
first line txanticoagulation (heparin and warfarin) — to prevent new clots (as body is naturally taking care of old clots)
prophylactic tx (and indication)anticoagulation (heparin and warfarin) - hospitalization and surgery
risk of thrombolysis*bleed
3 thrombolyticsTpA, strotokinase, urokinase
indications of IVC filtercannot use anticoagulants or thromboembolus recurrence despite anticoagulation
memorize

PATH of pulmonary vascular disease

Pulmonary Embolism
Question Answer
Trousseau's is risk factor forPE/DVT
cor pulmonale & PEdilation of right heart due to local increased resistance
*****gross path of MASSIVE embolismNo parenchymal changes - -b/c died too quick!
explain hemorragic infarctsdue to DUAL blood supply (occlusion in pulmonary a / re-supplied by bronchial system)
lines of zahn indicatePREMORTEM formation -- thrombus was organized in vein
saddle embolismlocation
be able to differentiate PE from plexiform lesion20.16 vs. slide 20.29
PE risk factorshypercoagulable state, carcinoma, Trousseau's syndrome, ORAL contraception, pregnancy, inactivity
memorize

 

Pulmonary Hypertension
Question Answer
key histo finding in PAHPLEXIFORM LESION
demographic assc of PAHyoung women (also assc w/ collagen vascular disease)
grade IV lesion/ Vplexiform lesion
grade III lesion"onion ring appearance
Plexiform lesion would show ____ stainELASTIC
early vs late pulm HTNmuscular hyperterophy >>> intimal thickening (and potential obliteration)
memorize

 

***Vasculitic Disorders:
Question Answer
assc w/ C-ANCA (antineutrophillic cytoplasmic antibody)GPA / wegener's
GPA / wegener's - classic tradsinus / lung / renal (usually multiple lung nodules)
GPA / wegener's - demographic50 y/o /male
GPA / wegener's - histoparenchymal necrosis -- ATYPICAL granuloma w/ vasculitis of smaller vessels
assc w/ N-ANCA (antineutrophillic cytoplasmic antibody)Churg-Strauss, **microscopic polyangiitis
Churg-Strauss - triadasthma / eosinophilia / vasculitis (w/ any cell type) +++ cardiac and nasal involvement
Churg-Strauss- CXRmultifocal infiltrates
Churg-Strauss - histoasthmatic bronchitis + eosinophillic penumonia _ GRANULOMAS (palisaded histiocytes around central necrosis )
Microscopic polyangiitis- definepauci-immune vasculities - in SMALLEST vessels
Microscopic polyangiitis - systemic manifestationsglomerulonephritis***, fever, myalgia/arthralgia
Microscopic polyangiitis- histodiffuse AVEOLAR hemorrage w/ neutrophilic capillaritis (and no immunoglobulin seen)
key clinical fea. of diffuse alveolar hemmorrahgeHEMOPTYSIS
memorize
*****