| HELLP syndrome | |
|---|---|
| Classification and external resources | |
| ICD-10 | O14.1 |
| ICD-9 | Not assigned |
| DiseasesDB | 30805 |
| MedlinePlus | 000890 |
| eMedicine | ped/1885 |
| MeSH | D017359 |
HELLP syndrome is a life-threatening obstetric complication usually considered to be a variant of pre-eclampsia. Both conditions usually occur during the later stages of pregnancy, or sometimes after childbirth.
HELLP is an abbreviation of the main findings:[1]
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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 paresthesia (tingling in the extremities). Edema 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 has a seizure or coma, the condition has progressed into full-blown eclampsia.
Disseminated intravascular coagulation is also seen in about 20% of all women with HELLP syndrome,[2] and in 84% when HELLP is complicated by acute renal failure.[3]
Patients who present symptoms of HELLP can be misdiagnosed in the early stages, increasing the risk of liver failure and morbidity.[4] Rarely, post caesarean patients may present in shock condition mimicking either pulmonary embolism or reactionary haemorrhage.
HELLP syndrome can be difficult to diagnose due to the variability of symptoms among patients (frequently patients have no symptoms other than general abdominal pain), and early diagnosis is key in reducing morbidity. If not treated in a timely manner, a mother can become critically ill or die due to liver rupture/hemorrhaging or cerebral edema.
Vitamin B12 deficiency should be ruled out by testing for it directly, not relying on a complete blood count. Elevated homocysteine levels are strongly suspicious of vitamin B12 deficiency, which is masked by folic acid supplementation in prenatal vitamins. http://www.jhoonline.org/content/1/1/26 http://www.ncbi.nlm.nih.gov/pubmed/19304410
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.
A positive D-dimer test in the presence of preeclampsia has recently been reported to be predictive of patients who will develop HELLP syndrome.[4] D-dimer is a more sensitive indicator of subclinical coagulopathy and may be positive before coagulation studies are abnormal.
The platelet count has been found to be moderately predictive of severity: under 50,000/mm3 is class I (severe), between 50,000 and 100,000 is class II (moderately severe) and >100,000 is class III (mild). This system is termed the Mississippi classification.[5]
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.
The only effective treatment is prompt delivery of the baby. 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. Hepatic hemorrhage can be treated with embolization as well if life-threatening bleeding ensues.
Its incidence is reported as 0.2-0.6% of all pregnancies, and 10-20% of women with comorbid preeclampsia. HELLP usually begins during 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. The outcome for mothers with HELLP syndrome is generally good. With treatment, maternal mortality is about 1 percent. However complications have been observed, including placental abruption, acute renal failure, subcapsular liver hematoma, and retinal detachment.[2]
HELLP syndrome was identified as a distinct clinical entity (as opposed to severe preeclampsia) by Dr Louis Weinstein in 1982.[1]
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