低血鈣鑒別診斷與治療

目錄鈣磷代謝的調(diào)節(jié)低血鈣的臨床表現(xiàn)低血鈣的病因鑒別診斷治療第1頁/共37頁鈣磷代謝的激素PTH維生素D降鈣素第2頁/共37頁第3頁/共37頁第4頁/共37頁臨床表現(xiàn)急性神經(jīng)肌肉：麻木感，抽搐，喉痙攣，癲癇發(fā)作精神癥狀：焦慮，抑郁，記憶力下降，易激惹，精神病心血管:心悸，氣短，胸痛，頭暈第5頁/共37頁臨床表現(xiàn)慢性基底節(jié)鈣化皮膚毛發(fā)干燥，指甲易碎視乳頭水腫白內(nèi)障顱內(nèi)壓增加第6頁/共37頁體格檢查評價神經(jīng)肌肉興奮性(Chvostek‘s，Trousseau'ssigns)心血管：心律失常，心動過緩，低血壓，心衰頸部手術瘢痕其他內(nèi)分泌異常(如腎上腺功能不全)兒童生長發(fā)育障礙，先天異常，聽力障礙，智力障礙提示可能為遺傳病第7頁/共37頁病因低白蛋白血癥甲旁低維生素D相關疾病包括腎功能不全鈣結合改變骨吸收抑制第8頁/共37頁甲旁低PTH分泌減少PTH抵抗（假性甲旁低）分型1a（Albright'shereditaryosteodystrophy),1b,1c,and2

第9頁/共37頁PTH分泌減少甲狀腺、甲狀旁腺手術后(最常見原因）特發(fā)性(散發(fā))自身免疫性（單獨或自身免疫多內(nèi)分泌腺綜合癥1型）甲狀旁腺發(fā)育不良(DiGeorgesyndrome,hypoparathyroidism-deafness-renaldysplasia,Kenney-Caffeysyndrome)浸潤性疾病(地中海貧血，血色病，Wilsondisease,腫瘤轉移)頸部放療可逆性(低血鎂，高血鎂)

低血鎂原因：飲酒，藥物，腎臟疾病，代謝性酸中毒，糖尿病，腹瀉，吸收不良，營養(yǎng)不良一過性（新生兒）

第10頁/共37頁維生素D相關疾?。壕S生素D前體物質缺乏:

攝入減少紫外線照射不足吸收不良肝臟疾病異常肝腸循環(huán)藥物(phenytoin,phenobarbital)

腎病綜合癥活性代謝產(chǎn)物轉化下降VitaminD-dependentricketstype1(1alpha-hydroxylasedeficiency)作用抵抗

VitaminD-dependentricketstype2第11頁/共37頁鈣結合改變高血磷

枸櫞酸

呼吸性堿中毒急性嚴重疾?。〝⊙Y，燒傷，胰腺炎，中毒性休克）第12頁/共37頁骨吸收抑制降鈣素光輝霉素二磷酸鹽治療第13頁/共37頁實驗室檢查血清鈣，游離鈣PTH血磷血鎂腎功能第14頁/共37頁輔助檢查ECG：QT間期延長，心律失常第15頁/共37頁進一步實驗室檢查25(OH)vitaminD1,25(OH)2vitaminD

淀粉酶、脂肪酶ALP電解質24小時尿尿cAMP排泄試驗第16頁/共37頁第17頁/共37頁第18頁/共37頁治療靜脈輸注葡萄糖酸鈣①威脅生命：癲癇發(fā)作，手足搐搦，低血壓，心律失常②急性低血鈣癥狀第19頁/共37頁靜脈輸注110%葡萄糖酸鈣10~20毫升（10分鐘以上）緩慢靜脈推注（稀釋以后滴注：20毫升入100毫升5%葡萄糖10~15分鐘以上）之后持續(xù)靜脈滴注：0.5~2mg元素鈣/kg/小時4~6小時監(jiān)測血鈣（目標血鈣7~9mg/dL）1毫升10%葡萄糖酸鈣含9mg元素鈣1毫升10%氯化鈣含27mg元素鈣第20頁/共37頁靜脈輸注2單次短時間輸注離子鈣1-1.12mmol/L:20ml10%葡萄糖酸鈣入50-150mL（5%葡萄糖或0.9%

氯化鈉）2小時輸注.離子鈣<1mmol/L:40ml10%葡萄糖酸鈣入50-150mL4小時輸注.糾正電解質紊亂（低血鉀，低血鎂）第21頁/共37頁口服補鈣元素鈣1500~2000mg/日劑量更高（甲旁低）：起始元素鈣500~1000mgtid,多數(shù)終劑量1000~2000mgtid,目標血鈣正常低限，24小時尿鈣<1mmol/kg(4mg/kg），減少P攝入副反應：胃腸道反應（惡心，嘔吐，便秘）第22頁/共37頁第23頁/共37頁第24頁/共37頁第25頁/共37頁甲旁低X-linkedrecessive:NeonatalonsetAutosomal-dominantandautosomal-recessiveforms:Chromosome3q13:Activatingmutationsinthecalcium-sensingreceptor(CaSR)geneChromosome6p23-24:HomozygouslossoffunctionofGCMBgene(transcriptionfactorrequiredforparathyroidglandembryology)Chromosome10p15:GATA3genemutationscausedominantlyinheritedfamilialhypoparathyroidism,sensorineuraldeafnessandrenalanomaly([HDR]syndrome).Chromosome11p:MutationsinthePTHgeneChromosome22q11:DiGeorgesyndromeChromosome21q22(AIREgene):Type1polyglandularautoimmunediseaseChromosome20q13:Albrighthereditaryosteodystrophy第26頁/共37頁甲旁低Mitochondriadiseases:Kearns-Sayresyndrome(progressiveexternalophthalmoplegiabeforeage20yearsandpigmentaryretinaldegeneration,frequentlywithotherorgansysteminvolvementincludingcardiac,neurologic,andhypoparathyroidism)第27頁/共37頁分類1TransientFetalparathyroidsuppression:Maternalhypercalcemia,diabeticmotherHypomagnesemia:Directeffects(suppressedPTHsecretion,increasedPTHresistance)Alcoholintoxication第28頁/共37頁分類2CongenitalFamilial:X-linkedrecessive,autosomaldominant,autosomalrecessiveSporadicandisolatedDiGeorgesyndrome:Parathyroidglandhypoplasia,thymichypoplasia/aplasia,facialabnormalities,aorticarchandcardiacdefects第29頁/共37頁分類3Acquired:PostsurgicalPostirradiationFollowingsevereburnsType1polyglandularautoimmunedisease(Blizzardsyndrome):Hypoparathyroidismassociatedwithchronicmucocutaneouscandidiasisandautoimmuneadrenalinsufficiency;canalsohavediabetesmellitus,lymphocyticthyroiditis,hypogonadism,perniciousanemia,chronichepatitisIrondeposition:Thalassemia,hemochromatosisCopperdeposition:WilsondiseaseMetastaticcarcinomaMiliarytuberculosis第30頁/共37頁分類4Pseudohypoparathyroidism:ResistancetoPTH:Albrighthereditaryosteodystrophy:Gproteinmutation第31頁/共37頁病理生理DiminishedorabsentPTHactivityresultsin:HypocalcemiaandhyperphosphatemiaReducedvitaminDactivationto1,25(OH)2-vitaminDHypocalcemialeadstoincreasedneuralexcitability.第32頁/共37頁體格檢查Chvosteksign:Facialnervestimulation(tappinganteriorofexternalauditorymeatus)causescontractionoforbicularisoris,producingupperlipormouthtwitch.Trousseausign:InflationofBPcuffreducesthebloodflowtoperipheralmotornervesandtherebycanelicitcarpopedalspasminlatenttetany.CarpopedalspasmLaryngealstridorMentalstatuschangesIrritabilityPapilledemaCataractsBradycardia,hypotensionDryskin,coarsehair,brittlenailsAlbrighthereditaryosteodystrophy(pseudohypoparathyroidismtypeIa):Shortstature,roundface,thickneck,barrelchest,obesity,subcutaneouscalcifications,brachydactyly(short4thmetacarpalbones)第33頁/共37頁鑒別診斷Hypocalcemia:VitaminDdeficiencyVitaminD–dependentricketstypeIandIIHyperphosphatemiaPrematurityAcutepancreatitisMalignancy:Osteoblasticmetastases,tumorlysissyndromeMedication:Citratedbloodproducts,phenobarbital,dilantin,phosphate第34頁/共37頁維生素D治療1,25(OH)2-vitaminD:<1year:0.04–0.08mcg/kg/d;1–5years:0.25–0.75mcg/d;>6yearsandadults:0.5–2mcg/d第35頁/共37頁預后long-termou