OB/Critical Care (need to know) Flashcards
What is the leading cause of postpartum hemorrhage? Other causes?
The leading cause of postpartum hemorrhage is uterine atony
Other less common causes include trauma due to lacerations, uterine rupture, surgical incision bleeding, and coagulopathy. Coagulopathy during pregnancy or delivery may be associated with HELLP syndrome (hemolysis, elevated liver enzymes, low platelets), amniotic fluid embolism, placental abruption, or preeclampsia
What is the definition of postpartum hemorrhage?
- Cumulative blood loss ≥1000 mL, or
- Bleeding associated with signs and/or symptoms of hypovolemia within 24 hours of the birth process, regardless of delivery route (vaginal delivery or cesarean section)
Risk factors for postpartum hemorrhage?
These include the following: history of chorioamnionitis, magnesium sulfate exposure, macrosomia of the fetus, prior history of atony, multiple gestations, and multiparity. The patient above has several of these risk factors, placing her at an increased risk for uterine atony.
What is the treatment for postpartum hemorrhage?
Uterine atony is the leading cause of postpartum hemorrhage and should be treated initially with intravenous oxytocin and simultaneous uterine massage.
Typically, the uterus will feel soft, enlarged, and boggy; this is due to loss of tone in the uterine musculature. Prior to diagnosis, the physician will also explore the lower genital tract as well as inspect the placenta and send out clotting tests to rule out other causes. In uterine atony, the uterus fails to contract; therefore, the blood vessels that were once feeding a quite-vascular placenta are not compressed, leading to hemorrhage. Strong uterine massage with simultaneous administration of oxytocin helps the uterus to contract down and become firm.
Once treatment with uterine massage and oxytocin has failed, typically the 4 “T’s” are assessed. The 4 T’s are uterine tone, trauma, tissue, and thrombin (clotting). This patient has no retained products of conception (tissue) and has not sustained trauma (no lacerations seen), and clotting times have been sent. Uterine tone must be addressed. The next best temporizing measure to address tone, after fundal massage and oxytocin with the addition of a second uterotonic medication (methylergonovine in this case), is balloon tamponade.
General flow steps for uterine atony treatment?
There are no randomized controlled trials on the treatment of uterine atony. The following should be tried, generally in order of least to most invasive, while the patient undergoes appropriate resuscitation with blood products and fluid. If the patient is unstable and temporizing measures fail, the patient should go immediately for hysterectomy.
Oxytocin, then add a second uterotonic medication
Uterine massage
Repair any lacerations
Consider tranexamic acid
Balloon tamponade or intrauterine packing
Laboratory evaluation of prothrombin time/partial thromboplastin time, hemoglobin, electrolytes, fibrinogen
Compression sutures and devascularization (uterine artery ligation); would only be done if cesarean delivery and the patient is still open
Appropriate blood products to treat underlying coagulopathy and IVF
Aortic compression
Uterine artery embolization
Hysterectomy
What is HELLP syndrome? Diagnosis and treatment?
HELLP syndrome is a complication that occurs late in pregnancy and that is defined by hemolysis, elevated liver-enzyme levels, and low platelet counts; all three conditions must be present to make the diagnosis of HELLP syndrome.
This patient already has laboratory evidence of hemolysis in the form of her low hemoglobin level, the presence of schistocytes on peripheral blood smear, and her low platelet count (less than 100,000/μL). Therefore, to be diagnosed as HELLP syndrome, this patient’s condition needs evidence of an elevated level of liver enzymes, defined as aspartate- or alanine-transaminase (AST/ALT) concentrations that are twice the upper limit of the normal range.
The clinical scenario in a case of HELLP syndrome often is similar to that of preeclampsia (proteinuria and elevated blood pressure), but these findings are not required for diagnosis. HELLP syndrome likely represents a severe form of preeclampsia; however, the association is still controversial. The etiology is unknown, but clinical manifestations are explained by vasospasm, which leads to hemorrhage and organ necrosis. Risk factors include nulliparity, African-American ethnicity, extremes of age (younger than 20 or older than 35 years), multiple gestation, molar pregnancy, renal disease, previous HELLP or preeclampsia, and chronic hypertension.
The cornerstone of treatment is prompt delivery after maternal stabilization. In some clinical situations, delivery can be deferred by 48 hours to allow for administration of corticosteroids for fetal lung maturity (in pregnancies of less than 34 weeks of gestation). Additionally, magnesium-sulfate therapy should be initiated for seizure prophylaxis, and any severe-range blood pressures should be controlled.
Nifedipine use in pregnancy?
Nifedipine is a tocolytic that is given to patients in preterm labor prior to 34 weeks’ gestation to help delay delivery until after a course of steroids has been administered. In the setting of preeclampsia with severe features and HELLP syndrome, delivery after 34 weeks is indicated, and therefore, a tocolytic would be contraindicated. It is reasonable to administer betamethasone for fetal lung maturity; however, it would be inappropriate to delay delivery to do so.
What is one contraindication to mag sulfate use?
Myasthenia gravis is a contraindication to giving a patient magnesium sulfate. Myasthenia gravis is an autoimmune disorder that leads to fluctuating muscle weakness and fatigue. These patients have circulating antibodies that block acetylcholine receptors. Magnesium sulfate works by allowing magnesium to compete with calcium channels. Therefore, this medication will have deleterious effects on neuromuscular transmission.
In patients who meet criteria for pre-eclampsia with severe features how do we manage them?
This patient has persistent severe range blood pressures requiring IV antihypertensives, therefore she meets criteria for preeclampsia with severe features. In patients in whom blood pressures can be controlled with IV and oral antihypertensive therapy and with reassuring fetal status, inpatient expectant management with antenatal corticosteroid course and delivery at 34 weeks gestation may be undertaken.
What is the initial management of Pre-eclampsia?
This patient has signs and symptoms concerning for severe preeclampsia (blood pressure greater than 160/100 mmHg and dipstick with 5+ proteinuria as well as progressive renal failure) at 37 weeks. Preeclampsia is characterized by elevated blood pressure with proteinuria or evidence of end-organ injury in pregnant patients at >20 weeks gestation without pre-existing hypertension or renal disease. Patients at term and with severe preeclampsia should be promptly managed with hydralazine (or labetalol) to lower the blood pressure and magnesium sulfate to prevent progression to eclampsia. Once initial stabilization has been obtained, delivery should be carried out.
Delivery is recommended for all preeclamptic patients when they reach 37 weeks gestation or earlier for those who develop features of severe disease or fetal compromise (e.g., fetal growth restriction). Delivery before these endpoints is not recommended to avoid complications associated with prematurity unless the patient is not able to be managed medically.
