NBME 22 Dilution of serum sodium due to ADH (vasopressin) secretion (NBME Answers)

NBME 22 Answers ↦

nbme22/Block 1/Question#1 (107.1 difficulty score)
A 66-year-old man develops worsening ...
Dilution of serum sodium due to ADH (vasopressin) secretion🔍,📺
tags: RAAS

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+20
submitted by imgdoc(142),

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I tnhik otal fo oeplpe gtmhi hvea orve zdipsamhee hwo trtmnpoai ANP nda PBN llyear rae, yes ti si ttoripanm to konw seeth tdpeesip teg deecster yb eth tratenrircalvua/li uacridmmyo gnduri htrae .ireflau veorewH thier lroveal efeceisvnefst ni rtatngie earth leaurfi is z,hilc a etropprce tldo me ttah fi PNA dna PNB ewre os flueus ni siterrusina enth wyh od we vgie d?estuciir It's acbeues SARA vproeeoswr sthi stsyme nhece acgnuis tneaivge efsfcte and eth enelsds olop of htear faeriu.l KAA wyh we gevi CEA oiibnits.rh

Kgnwion thta PNA tesg dueetlizrna yb teh AARS ,smstye we nac ithsf uor uofsc abkc to htrae iareflu in iths apeitt,n hrewe drccaai tuoutp si sderea,dec dneaigl ot ADH ecrsietno and lnfiyal iuldonilat ihaprm.yaento

almondbreeze a concept continuously emphasized by uw, but I get always wrong :'( +2

almondbreeze good work done! +

raffff why does the body make anp at all since its so useless +3

makinallkindzofgainz @raffff - at least BNP gives us a good marker for heart failure exacerbations :) thanks body! +

mannan Yeah it's important clinically because it has a high sensitivity (if negative, rule out) for Heart failure. +

alimd At the same time ANP inhibits renin release? +

+11
submitted by meningitis(574),

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I salo hhtuogt het smae as u,sbebb@l utb won inrgty to "syfui"jt siht yitrkc EMNB ineto:usq I kntih sith lroesvev no eth tcaf taht the attpnei ahs a GHHI lbood sreuresp neingma ew dosulh ofcsu on an easrwn atht paesnlix htob iseeancdr PB adn lmiayeoHvpo :e.(i sirceneda DHA hwhic sstocnatvosirc adn osla sbaosbr et,-ererawf hobt fo hhicw eriesanc PB and acesu yopo)ivehmal.

aeyMb if stih aiettnp were optsdcdemeaen wthi LWO BP, eno ldcou ihntk eomr tabuo .PAN

I slitl nhkti isht sqnioute si TOO rk.city

meningitis Sorry, hyponatremia* right? +

mantarayray I think that it's not ANP because ANP will cause a loss of Na but water will follow (they usually go together), whereas ADH will cause absorption of only water and will cause hyponatremia except only thought this post getting the question wrong :") +4

mantarayray Oops sorry the formatting is confusing: I think that it's not ANP because ANP will cause a loss of Na but water will follow (they usually go together), whereas ADH will cause absorption of only water and will cause hyponatremia. +2

pg32 @mantaray pretty sure you are right and that is the only way to get this question correct. Remembering that Na concentration really is a measure of water balance is key. If the pt is hyponatremic, that just means they have too much water in the blood, which is caused by ADH. If the patient was hypoVOLEMIC, that might mean they are losing too much Na. This is illustrated by pts with SIADH. They are hyponatremic, but euvolemic, meaning that they have too much water (hyponatremia from the ADH) but their Na balance is ok (due to excretion of Na via ANP/BNP) +

avocadotoast We need to be thinking about how heart failure is a condition with a low effective circulating volume. Our patient had an MI and now his heart cant keep up with the volume (low CO), leading to congestion. When congestion occurs, water is pushed into the interstitial spaces and isn't circulating in the arterial system. For that reason, the body ramps up the RAAS and ADH despite an actual increase in body water. This is a non-osmotic release of ADH. At this point plasma sodium levels are determined by relative intake and losses and hyponatremia is common in these patients because of that. Also, ANP and BNP don't hold a candle to the RAAS. +

+4
submitted by nwinkelmann(311),

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moFr tUpeToaD: GSPINHETOAES

eikL tmos theor csuase of aemoa,thynrip eatrh rfuilea amirsip het abtylii to ctxreee sgeneitd atrew yb igicsnaenr itaudrtceiin rhnmeoo lles.ev enWh acdcari puttou nda ytsmcies bolod rerspseu ear e,dcured mcivolh"yeo"p mooer,nsh csuh sa inner wit(h a esqunbutse aecsirne in aignstnoien II roian)t,fom ucairiienttd mroohne D(H)A, nda inoprhpieneen,r soerpdn .-3][1 uohtglAh temoesaud psitntea whti herta areiflu aevh aeencidrs maaspl dan telclureraxla fiuld ,oulvesm eht doyb eepsceivr omlvue elpeitond deudec(r efvefiect arlaeirt lbodo moveu)l scnie teh owl accdira puuott esdeecsar eth rrueepss nrseiupfg het sbteropeorcar ni teh raocidt snsui and eth lnrea afentfer ir.et roealTeh greeed fo olaurohenmru vaictinota si enraegyll ladetre ot eht iteyersv fo raccaid iu,nscdotfyn as sseeadss yb ltef vlrrutaniec eoetinjc tocfirna or tuoncilnaf aclss .[2] ehT ureuhnaomlro ngcehsa milit hbot imdsou nad rewat eorextcin in na mteaptt ot unerrt rfsniupoe prureess to .lmnroa HDA lsreaee dycrliet encanshe trewa orabrniespto ni het glneoitlcc us,utebl eesrwha nnnoigsiaet II and rneperiineopnh imitl dislta rteaw vrieldey (nad hytrebe eratw toeerxcn)i yb lionrwge hte amuolrlgre aotfiitnrl reta (edu to a dakrme teidnrouc in nrela psif)rueno dna by cigaisnenr rmpioxal doisum dan treaw nbosprioreat 4[]. nI i,intdado btoh teh wol arccaid potutu and ghhi stoniagnine II svllee are tpenot usimtil to hitsrt, genladi ot aednnhec wreat atk.nei

/hriHwtnynsepa.nei/reu-e-e2/aoot/hwaatmtsitwtmepipt-pwtl#udcthts-cnnahftir:.aoo-

+3
submitted by bubbles(72),

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hisT entiquso fsonduce me a tlo ecbeusa so nyam tsoqniuse veha drdllei em on eth mnitorcpae fo het NPA pecsae iammneshc ni mties fo fuild rdaelvoo (sa in .HF)C

I tthoguh NPA saw a eghu ayelpr ni hte lsso of Na ni msuccrnitcase of omlveu edlovaro sa ni shti ptantei w(hihc is yhw oyu ees olmvuceei tehpOimanyra in sntatiep htwi HIDSA or trvyavoeiitc fo het AARS sa in C).FH

Why is HAD nwo igneb nemad sa the blresosneip ega?tn

jooceman739 My thinking is that ANP causes natriuresis, so you're losing salt and water at the same time (isoosmotic fluid?). Meanwhile, ADH absorbs only free water, so it would dilute the serum. Correct me if i'm wrong. +11

bubbles Ohhh you are right. Thank you for the explanation! I got so fixated on that one mechanism haha. +3

+2
submitted by dr.xx(157),

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HCF npeittas oetfn pilsayd insgs nad sommspyt fo eciresdan sovseiarnsp ci.seeortn

hyperfukus if all else fails i hope i just drill this one statement in my brain and it comes out in the right way on test day thank u!!! +

+1
submitted by moloko270(69),

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2dcwt8ngnw8un5hbmh7e/pis2.:/0bv/p.t/l.woim.

reydn"smo of alnuidoilt" iytmpolsa-hol"yo in vrseee icveetgson aerth alurefi amy eb csadeu by an arplaornitppeyi ghhi AHD resinotec in iwhhc eht oocpesrometr ystesm is etoinadmd by nrnooslmoa um"itisl

hayayah Apparently, in chronic CHF you see hyponatremia. Because CHF causes a decrease in cardiac output and circulating blood volume, which in turn triggers a compensatory response aimed at preserving blood pressure. This stimulates the body to retain both water and sodium. +9

seagull i agree with Hayayah... the RAAS system is activated due to poor perfusion to the kidney due to decomp heart failure. +5

+1
submitted by drmohandes(139),

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rHee ew :go

dsdacreee VL ryittcoclnati earbil(lat sl)arcekc
creseedda cdairca ptoutu
ectaiavt RASA → HAD
caerisen aispeytctmh yaiitctv → emor SRAA → more HAD

+0
submitted by happysingh(45),

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i dnaik of eelf dd"o" sgkain iths uenqtsio : ubt eth natietp dha na IM 6 sonhmt ag,o so wyh owdlu it eb ilnkelyu taht eh wsa dlot ot tcsirtr"e lsta, rerittcs iufsld (a)ewtr " ??

Guess ahwt mi' iskang is : htwa amsek eicoch E scuh an llneyiku coihce ,(JDV bla-iasirb ,sccaerkl eapelprhri )eedma ?

a;p&m i@gnmtseiin : shi pb is 5/8312 Hgmm ... ywh is ttah HGI"H" ??

+0
submitted by nicsar(1),

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maaHneotpyri frmo fleHrretuiaa tp.

tI sulhod be hodpapraec ofrm aHert fir.aue

;g-H&tF RAsA -g;t& veessiexc ,edosnrAtole DHA; NAP pceesa farue,i kiel ynescoadr ooimrspanld;rhytese tioneHyraapm

tw/CgJw06-l/sh11.234v/9w1.i/tp:h-og/t7jt/m54nfcu8-e9Wl9./w0-m5

+0
submitted by dubywow(19),

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secpnDtaomeed F.H Lcak of olobd wlfo ued ot nlagfii etarh tg-&; relwo PB -&t;g sencderai AHD to einrcase oolbd esserpur cabk ot aelbts lvle.e In DF,H ADH ucspeaot ehmsioostsa fo inctateonugcr PAN &;pam PBN. suTh, hte tmer pnoe.ae"std"dmce doitcseaAs with sseroshtn fo a,hetrb damee (tonfe fo u)s.lng

Tsih iciouvs lycec esuotncni as boyd sroitrzpeii uqdaetae PB orf ,ivvurasl but it scemo at hte neeexps of edvroekrwo treha ttha smtu rkwo rerhad dan a,edhrr mutleyital aaerebcgixtn het thear rieaful tocdinon.i

+0
submitted by asharm10(29),

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ywslaA nkwo stih oypH or reeahtraiympn is uebscea of hgnaec ni het uom,vle htis pitaetn si gonig oruhhtg taerh reif,ual lnrea usonepfir ash ogen onwd tath adsel ot resaeel of DHA osc of oosesceoprtrm isl.namittou wNo ghih ADH illw rorsbabe erom fere twera hatt lwil alde ot .ieorynhpmata So hpoarinmeayt si atlsom aawysl rltedae ot hgih HAD. I wonk few of yuo iwll nithk tbu ASAR ysetsm is tcitavade oto tub taht bbsaor aN nogal hitw rewta btu DHA sutj fere wtar.e

+0
submitted by hello(349),

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Trehe ahs ot eb a btrtee aponlatnxei fro yhw NPA si ngrw?o

waterloo If this pt's ANP/BNP were causing him to become hyponatremic, why does he have fluid overload symptoms (bilateral crackles, JVD, high BP)? There has to be something else overcoming the ANP system. +