HELLP syndrome

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HELLP syndrome is a life-threatening complication of pre-eclampsia. Both conditions occur during the latter stages of pregnancy, or sometimes after childbirth.

HELLP is an abbreviation of the main findings:

• Hemolytic anemia
• Elevated Liver enzymes and
• Low Platelet count

Signs and symptoms

Often, a patient who develops HELLP syndrome has already been followed up for pregnancy-induced hypertension (gestational hypertension), or is suspected to develop pre-eclampsia (high blood pressure and proteinuria). Up to 8% of all cases present after delivery.

There is gradual but marked onset of headaches (30%), blurred vision, malaise (90%), nausea/vomiting (30%), "band pain" around the upper abdomen (65%) and tingling in the extremities. Oedema may occur but its absence does not exclude HELLP syndrome. Arterial hypertension is a diagnostic requirement, but may be mild. Rupture of the liver capsule and a resultant hematoma may occur. If the patient gets a seizure or coma, the condition has progressed into full-blown eclampsia.

Patients who present symptoms of HELLP can be misdiagnosed in the early stages, increasing the risk of liver failure and morbidity (Padden, 1999).

Diagnosis

In a patient with possible HELLP syndrome, a batch of blood tests is performed: a full blood count, liver enzymes, renal function and electrolytes and coagulation studies. Often, fibrin degradation products (FDPs) are determined, which can be elevated. Lactate dehydrogenase is a marker of hemolysis and is elevated (>600 U/liter). Proteinuria is present but can be mild.

Classification

The platelet count has been found to be moderately predictive of severity: under 50 million/L is class I (severe), between 50 and 100 is class II (moderately severe) and >100 is class III (mild). This system is termed the Mississippi classification (Martin et al 1990).

Pathophysiology

The exact cause of HELLP is unknown, but general activation of the coagulation cascade is considered the main underlying problem. Fibrin forms crosslinked networks in the small blood vessels. This leads to a microangiopathic hemolytic anemia: the mesh causes destruction of red blood cells as if they were being forced through a strainer. Additionally, platelets are consumed. As the liver appears to be the main site of this process, downstream liver cells suffer ischemia, leading to periportal necrosis. Other organs can be similarly affected. HELLP syndrome leads to a variant form of disseminated intravascular coagulation (DIC), leading to paradoxical bleeding, which can make emergency surgery a serious challenge.

Treatment

The only effective treatment is delivery of the baby, preferably by cesarean section. Several medications have been investigated for the treatment of HELLP syndrome, but evidence is conflicting as to whether magnesium sulfate decreases the risk of seizures and progress to eclampsia. The DIC is treated with fresh frozen plasma to replenish the coagulation proteins, and the anemia may require blood transfusion. In mild cases, corticosteroids and antihypertensives (labetalol, hydralazine, nifedipine) may be sufficient. Intravenous fluids are generally required.

Epidemiology

Its incidence is reported as 0.2-0.6% of all pregnancies. Of women with (pre)eclampsia, 4-12% also develop signs of a "superimposed" HELLP syndrome. Mortality is 7-35% and perinatal mortality of the child may be up to 40%. HELLP usually begins after the third trimester, and usually in Caucasian women over the age of 25. (Padden, 1999.) Rarely, cases have been reported as early as 23 weeks gestation.

History

HELLP syndrome was identified as a distinct clinical entity (as opposed to severe preeclampsia) by Dr Louis Weinstein in 1982.

See also

• Acute fatty liver of pregnancy

References

• Martin JN Jr, Blake PG, Lowry SL, Perry KG Jr, Files JC, Morrison JC. Pregnancy complicated by preeclampsia-eclampsia with the syndrome of hemolysis, elevated liver enzymes, and low platelet count: how rapid is postpartum recovery? Obstet Gynecol 1990;76:737-41. PMID 2216215.
• Weinstein L. Syndrome of hemolysis, elevated liver enzymes, and low platelet count: a severe consequence of hypertension in pregnancy. Am J Obstet Gynecol 1982;142:159-67. PMID 7055180.
• Padden MO. "HELLP Syndrome: Recognition and Perinatal Management." Am Fam Physician. 1999 Sep 1;60(3):829-36, 839. PMID: 10498110