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RenalMain81-90Q1A66-year-oldmancomestotheclinicforafollow-upforhypertension.TwomonthsagoThehadhighbloodpressure(165/95mmHg)duringaroutineofficevisit,andsincethenhashad2follow-upvisits,bothdocumentinghighbloodpressure.Thepatientstatesthathecurrentlyhasnosymptomsandhasneverbeendiagnosedwithhypertension,buthedoeshavetype2diabetesmeliitusandhyperlipidemia.Heunderwentastentplacementforperipheralvasculardisease2yearsago.Thepatientisaformercigarettesmokerwitha25-pack-yearhistory.Currently,hisbloodpressureis162/93mmHg;andhisheartrateis73/minandregular.HisBMIis31kg/㎡,andphysicalexaminationisunremarkable.Serumcreatinineis0.3mg/dLCTangiographyreveals80%atheroscleroticnarrowingoftherightrenalartery.Inadditiontoantihyperlipidemictherapy,whichofthefollowingisthebestnextstepinmanagementofthispatient?A.DoxazosinB.LisinoprilC.LoopdiureticD.RenalarterystentingE.SurgicalrevascularizationA1Correctanswer:BRenalarterystenosis(RAS)isacommonfindinginolderpatients,withahighprevalenceinthosewithseverehypertensionorperipheralarterialdisease.Mostpatientswithhypertensionhaveessentialhypertension.However,renovascularhypertensionisthemostcommoncorrectablecauseofsecondaryhypertensionandshouldbesuspectedinailpatientswithresistanthypertensionanddiffuseatherosclerosis.PatientswithRASandrenovascularhypertensionshouldbemanagedwithaggressiveriskfactorreduction(aspirin,optimaldiabetesandhyperlipidemiacontrol,smokingcessation)topreventcardiovasculardisease.PatientswithhypertensionshouldbemanagedInitiallywithangiotensin-convertingenzymeinhibitors(ACEls)orangiotensinIIreceptorblockers(ARBs).Additionalantihypertensivetherapyshouldbeinstitutedasneededforoptima!bloodpressurecontrol.RAScausesdecreasedrenalbloodflow(RBF)andactivationoftherenin-angiotensinsystem,resultinginhypertension.ACE!therapyreducesangiotensinIIlevels,dilatingtheglomerularefferentarterioles.WithunilateralRAS,thestenotickidneyexperiencesreducedRBFandaresultantfallInglomerularfiltrationrate(GFR).However,theunaffectedkidneycompensatesforthisfallinGFRasitisnolongersubjecttoangiotensinll-inducedrenalvasoconstriction.WithbilateralRAS,thefallinGFRgenerallyleadstoariseinserumcreatinine(acceptableriseis30%);Inthissetting.ACEIsaresometimescontraindicatedbutcanstillbeusedwithcloserenalfunctionmonitoringduetotheirlong-termnephroprotectiveeffects.(ChoicesAandC)SeveralantihypertensiveagentsareusedinconjunctionwithACEisorARBsforadequatebloodpressurecontrol.Theseincludecalciumchannelblockers(eg,amiodipine,feiodipine,diitiazem),thiazidediuretics(eg,chlorthalidone),betablockers(eg,metoprolol,atenolol,labetalol),andmineralocorticoidreceptorantagonists(eg,spironolactone).However,doxazosinorloopdiureticsarenotrecommendedasafirst-lineagentforhypertension.(ChoicesDandE)Revascularization(surgicalorpercutaneousangioplastywithstenting)hasnotbeenprovensuperiortomedicaltherapyforoptimalbloodpressurecontrolorreductionofcardiovascularoutcomesinpatientswithunilateralorbilateralRAS.Itisreservedforselectedpatientswhoareintolerantorfailtoachieveadequatebloodpressurecontrolwithoptimalmedicaltherapyandforthosewithrecurrentflashpulmonaryedemaand/orrefractoryheartfailureduetoseverehypertension.Educationalobjective:Angiotensin-convertingenzymeinhibitorsorangiotensinlireceptorblockersareindicatedforinitialtherapyinpatientswithhypertensionandrenalarterystenosis.Renalarterystentingorsurgicalrevascularizationisreservedforpatientswithresistanthypertensionorrecurrentflashpulmonaryedemaand/orrefractoryheartfailureduetoseverehypertension.Q2A26-year-oldmancomestotheemergencydepartmentbecauseofasuddenonsetofsevereright-sidedflankpain.Thepainiscolickyandradiatesfromtheflanktothescrotum.Healsohasnausea,vomitinganddark-coloredurine.Hehasneverhadthesesymptomsbefore.Histemperatureis37°C(98.6°F),bloodpressureis126/70mmHg,pulseis90/min，andrespirationsare18/min.Examinationshowsnoabnormalities.Heisgivenadequateanalgesia.Non-contrasthelicalCTshowsa4mmradiopaquestoneintherightupperureter.Laboratorystudiesshowserumcalciumof9.8mg/dL,serumcreatinineof0.9mg/dLrandBUNof15mg/dL.Urinalysisshowshematuriabutnocasts.Whichofthefollowingisthemostappropriatenextstepinmanagement?A.24hrurinecollectionformetabolicevaluationB.ReassuranceC.Fluidintakegreaterthan2L/dayD.intakeofpotassiumcitrateE.RestrictionofdietaryoxalateA2Correctanswer:CThispatienthastheclassicclinicalpresentationofnephrolithiasis.Thefollowingareimportantconceptsinthemanagementofsuchpatients.1.Imagingstudy-CTscanoftheabdomenwithoutcontrastistheInvestigationofchoicebecauseofitshighsensitivityandspecificity.Ithastheadvantageovertheplainabdominalx-ray(KUB)indetectingtheradiolucentstones.2.NarcoticsandNSAIDs-Theseareequallyeffectiveinrelievingthepainofacuterenalcolic;however,inpatientswithnormalrenalfunction,NSAIDsarepreferredovernarcoticsbecausethelattercanexacerbatenauseaandvomiting.3.Sizeofthestone-Stonesmeasuringlessthan5mmindiametertypicallypassspontaneouslywithconservativemanagement.Thisincludesafluidintakeofgreaterthan2Ldaily.Increasedhydrationincreasestheurinaryflowrateandlowerstheurina