Laboratory Tests

• The unstimulated serum cortisol and rapid ACTH stimulation tests are useful in the diagnosis of adrenal crisis (Table 45-2). The insulin tolerance test is contraindicated due to pre-existing hypoglycemia. The metyrapone test is also contraindicated since metyrapone inhibits cortisol production.

Note: Due to the life-threatening nature of this condition, empiric treatment should be started before laboratory confirmation in patients who present with the clinical picture of an acute adrenal crisis.

Table 45-2 Tests for Diagnosing Adrenal Insufficiency

Test

Protedure

Rationale

FJndFng In Adrenal Intuffldency

Comments imct ni ng and D lagnistk Test j for Adrenal Iniuff k leiKy yrmimulaied tit um ttiimJ moJiitfCiiiCiH

ftjptd Ai.ni stlntailalkm res! (JIMJ wllefl ctHym ropin mrmiadM

insulin «Heran«

test llnudin injjc«) hypoqtywriU led

Mfuyjie Strum «yiliol iÖ-öj nwHjbcs JII:L"I rtrinliteflnj fosyntropln KOmftjIV

Administer In^jRnJV to Induce liytwgll^tmiJ mwvure scrum found

VHumcnfirvH level paAiai [he wrty mo<nin(t inc«»4cd CjOI riiCJ wcirtkvi in normal individuals

In <«(WTiKiC> ACTH si imulatlon tXll nut Irl idrcfdl

Insufficiency

(vulmfos abilityof tiiliif Hi'A jxis w respond to streu (liypoglytcfmd)

Serum rcmisnl nie.irei liun 16 mctjAil W97 nrinil/|) is nCKrti.ll Serum roinsol less l Inn S mitpUl (Si mnoi/L} is indn-iciue of 3(Jl*nl Insuflktency ierurm cexüvoi concofaralion less tlun IILmC9ML.(M7 rirnoVL)

Serum toMiaoi «MeHtticri kiH than IH mcgAA (-ID/ r»rtiSt/U is indkitm: Of s«orKiiay Imuffcieney

Used ssa ffcneffll inlrial vrwriiij teic for (he presence ufl adrerul iroufk »¡cy. tvj&j jie iHui in coniuiK (¡Oft wii h those ijom Iheothet lests

Liwd ¿s He («*) JUrtUiO wir ibf dtigfKKiiritj fiifiury adrenal irrtiifinTii >■ Fdlsii nuidtlvx1 results mdy occut if (twi ACTH dlfclinOf ll ef «CP* Oftj^ Ktt tlun I month} Mliöuyh no I wkJ.^ jiiOuDCtl. J kw ttwe [I mcc|) ACTl H Stimulation lest has Leen uselrf ior lhe diagnosis of pdi1>al üdlifUl Insufficiency If moaned vmm cuvtisol mncwKlraiicn is kw, mwyjte pldsma ACTH, Jtixiwtxv. JiX) rtnln to drfüerenluäle between primary .md vtmxiiryui lerlijry ocMeml Insufficiency (Me tvt>«)

li It*.1 lesultoi the rjpid ttll H stimulation («1 bnonnJ.tt(hw iMj c* lhe overnlghl nvtyrapone lest Is slill rn-Tdttl lötvdluMS ic SttöKldry AiiifyJinsuHiCPtirRy lheInsulin (oterante Ies1 kconwJwed the ii.jhl

[>emlghi metyraporu WE

during

^ympinmatlc hypoglycemia (confirm Uiat blood glucose ü kfis tfidii flOmg/KIL \2-22 mrnol/ljf

Administer metyTapcr» at inkJiiighH Chen measure itrum Cortisol it&jwthc new day f^eryrsporif- Inhibits Cortisol synthesis. Lis adrnmliltaL iun IqkJs to-rise in levels of ACTIi aod thepfKuisoof aJctfed, Paiieras y.-n h adrenal insufllcientydo rat exhibit this

Nor mal reippnw I? a decrease In serum Cortisol 1o Ich 1f»an S mtgrtJL (136 mrnolvl) and an ¡rKie.ne inllie Cortisol (ireairKir to monfThsfi 1 mccydL 4193 nmol/li flesfcnse not seen in secondary adrenal insufltiency

Plasma ACTH cjoncontrison

Measure plasma ACfH

In primary adrenal prriufiici^rtty, hypoccfiöJism IWJS ro elcufid plasma AjCTH concerHraticin via positive HPAaxfc foodlMCk

Primary adrenal insufficient y: tfcvdWd plasma ftCTH Secondary or terrify adrenal Insufüclency: plasma ACTH tow a inappropnately normal

Ptasma jfcJovlfiox-cnncvntranlcn

Plasma renin ttXKinträiiön Of XlHrtty

Measure plasma

Patients with

Pmmaiy adrenal

JKbtWiOiV

primary jdiervji

in^yffii isrtiy: lijw

from same

insufficiency

plasma aldosterone

NtxxJ

may (Bdjciianca

Secondary or tt*Hary

iimples ,TL

.1 nfitVif linn in

■fcliin.ll imicHli ifTH' y:

those used

aldosterone

aldosterone

In flCTH

prOduitiOfi

COfiCiMiilioii Ii usually

stimulation

rn.yni.il Dgieatrt 1han a

test

equal to S n^VJL

|li9pmol/l|)

Measure

Mlnerabcortkokd

PjTtsiy adrenal

pi«™ ienin

deitkiKyOCCtuS

insuffcieiitf elevated

concentration

In piiinaryddrcftil

pl~1<jTl.l KHKil

or activity

Insullkiency but k

Secondary or to liary

USuillytvji rwwnt

XliOrtil inSn/ilcietXy;

In secondary or

p4asma renin

(t«lijry jdienal

LUrwI'diO" or

Insufficiency

activity is usually

Contrgiodlcired In patient* with a seizure hi-iccwy. older than (iiJ yeais, of with cardiovascular oi ceictxovasculdr disease

RBfjjiiesibse inidtai yjpwrtston

ContrjindicatMl iriiclienal CiiSiS

Distinguishes between normal Individuals and patients with sec ondai y adianil insufficiency

Centra ^idkaltt) inadicnal uisis

Tests for Differential Diagnosis of Primary, Secondary, and Tertiary Adrenal Insufficiency

Evaluate resu'1 of test in combination wirh lhost from Hie plasmd akfcweBnaand plaiffia renin lttts

Evaluate result <J test ¿lcombiriaLiori With tlvjie'r<?m the 11■ J-I in I II jm £ plasma mm Inn

Evaluate ruiult of lest rnconlwvifiori with ih«e irotift rhe ptäirini a£Th mki piauna flklosfletijne concentration Tpsti

^TH. adicnocorticcHropic liormono-or corticotropin; CHH, codicotropiri releasing hormone; HltMrypotfulamic-piluilary ¿JrenJ. Fiom fiefs. J, S.

Table 45-3 Pharmacologic Characteristics of Commonly Used Glucocorticoids

f tlim*[(d Ponnty RrliH»r lo H.ydr$(UJl<njn(

Glucocorticoid iAnti-lnfl^mmatorv)

Mlneralocertkoid liodium-

Equivalent Daie

Glucocorticoid Activity

flttjinmgl Activity

fmq>

Short Acting ftUtf-Lrt* Leu (hwi U houri)

HydracaUBcrw 1

1

20

Cofii«ne

ftfl

Intermediate Acting 1 Half-Life 12-16 hour:)

fYedni-Lone 4

425

s

p^dnisotonc 4

(125

i

MethylptednKolone 5-

Less ttunfluEH

4

Tiiaircinokw

Lp-k rtun i)(lt

4

Long Actl ng [Half- Life Greater Than 48 hourc}

Qeiameitwöne is

LeK rtun am

OetameDwjone 30-40

L«4 trwiiacn

Your Heart and Nutrition

Your Heart and Nutrition

Prevention is better than a cure. Learn how to cherish your heart by taking the necessary means to keep it pumping healthily and steadily through your life.

Get My Free Ebook


Post a comment