HELLP syndrome

HELLP syndrome

Classification and external resources

SpecialtyObstetrics

ICD-10O14.2

ICD-9-CM642.5

DiseasesDB30805

MedlinePlus000890

eMedicineped/1885

Patient UKHELLP syndrome

MeSHD017359

HELLP syndromeis a life-threateningobstetriccomplication usually considered to be a variant or complication ofpre-eclampsia.[1]Both conditions usually occur during the later stages ofpregnancy, or sometimes afterchildbirth. "HELLP" is an abbreviation of the three main features of the syndrome:[2] Hemolysis ElevatedLiver enzymes LowPlatelet countContents[hide] 1Signs and symptoms 2Pathophysiology 3Diagnosis and classification 4Treatment 5Prognosis 6Epidemiology 7History 8See also 9ReferencesSigns and symptoms[edit]HELLP usually begins during the third trimester; rare cases have been reported as early as 21 weeks gestation. Often, a woman who develops HELLP syndrome has already been followed up forpregnancy-induced hypertension(gestational hypertension), or is suspected to developpre-eclampsia(high blood pressure andproteinuria). Up to 8% of all cases occurafterdelivery.Women with HELLP syndrome often "do not look very sick."[3]Early symptoms can include: In 90% of cases, eitherepigastricpain described as "heartburn" orright upper quadrantpain.[3][4] In 90% of cases,malaise.[4] In 50% of cases, nausea or vomiting.[4]There can be gradual but marked onset ofheadaches(30%), blurred vision, andparesthesia(tingling in the extremities).Edemamay occur but its absence does not exclude HELLP syndrome.Arterial hypertensionis a diagnostic requirement, but may be mild. Rupture of the liver capsule and a resultanthematomamay occur. If a woman has aseizureorcoma, the condition has progressed into full-blowneclampsia.Disseminated intravascular coagulationis also seen in about 20% of all women with HELLP syndrome,[5]and in 84% when HELLP is complicated byacute renal failure.[6]Pulmonary edemais found in 6% of all women with HELLP syndrome,[5]and in 44% when HELLP is complicated by acute renal failure.[6]A woman with symptoms of HELLP can be misdiagnosed in the early stages, increasing the risk of liver failure and morbidity.[7]Rarely, after a caesarean section surgery a woman may have signs and symptoms of a shock condition mimicking eitherpulmonary embolismor reactionary haemorrhage.Pathophysiology[edit]The exact cause of HELLP is unknown, but general activation of thecoagulation cascadeis considered the main underlying problem.Fibrinforms crosslinked networks in the smallblood vessels. This leads to amicroangiopathic hemolytic anemia: the mesh causes destruction ofred blood cellsas if they were being forced through a strainer. Additionally,plateletsare consumed. As theliverappears to be the main site of this process, downstream liver cells sufferischemia, leading to periportal necrosis. Other organs can be similarly affected. HELLP syndrome leads to a variant form ofdisseminated intravascular coagulation(DIC), leading to paradoxicalbleeding, which can make emergency surgery a challenge.An association has been demonstrated between long chain 3-hydroxyacyl-CoA-dehydrogenase deficiency (LCHAD deficiency) of the child and maternal HELLP andacute fatty liver of pregnancy(AFLP). This inherited, autosomal recessive abnormality of fatty-acid oxidation can result in significant morbidity and mortality in infants, if untreated. Treatment with dietary manipulation is possible. Approximately 80% of infants with LCHAD deficiency have been born after pregnancies complicated by AFLP or HELLP. However, what is not known is how many pregnancies complicated by AFLP or HELLP result in infants with LCHAD deficiency.[8]Diagnosis and classification[edit]HELLP syndrome can be difficult to diagnose due to the variability of symptoms among pregnant women (frequently a woman will have no symptoms other than general abdominal pain), and early diagnosis is key in reducing morbidity. If not treated in a timely manner, a woman can become critically ill or die due to liver rupture/hemorrhage or cerebral edema.In a woman with possible HELLP syndrome, a batch ofblood testsis performed: afull blood count, acoagulationpanel,liver enzymes,electrolytes, andrenal functionstudies. Often,fibrin degradation product(FDP) levels are determined, which can be elevated.Lactate dehydrogenaseis a marker of hemolysis and is elevated (> 600 U/liter).Proteinuriais present but can be mild.In one 1995 study, a positiveD-dimertest in the presence of preeclampsia was reported to be predictive of woman who will develop HELLP syndrome.[7][9]The diagnostic criteria for and subtypes of HELLP vary across studies, which "makes comparison of published data difficult."[1]The classifications include: Criteria developed at theUniversity of Tennessee:[4][10] HELLP is characterized by hemolysis onperipheral blood smearwith serumlactate dehydrogenase>600 IU/L; serumaspartate aminotransferase>70 IU/L; and platelet count