Hypotension in Pregnancy
Cardiac output increases by 40% at the end of the first trimester. The heart rate increases 10-15 beats per minute. Systolic and diastolic pressures decrease about 10 mmHg in the second trimester. In late pregnancy, the supine position compresses the inferior vena cava causing a further decrease in blood pressure. The left lateral position relieves this effect.
Vaginal bleeding and hypovolemic shock in early pregnancy may occur from spontaneous abortion or ectopic pregnancy, and in late pregnancy from abruptio placentae or placenta previa. A postpartum hemorrhage may also occur. If a spontaneous abortion becomes inevitable with heavy vaginal bleeding, treatment is fluid resuscitation with normal saline, followed by dilatation and curettage.
An unstable ectopic pregnancy,
indicated by abdominal pain, vaginal bleeding, hypotension and a positive pregnancy test, is diagnosed by culdocentesis (the stable patient is diagnosed by ultrasound). Treatment:
2 IV lines are started, packed red cells are given for hemodynamic instability, and the patient is prepared for surgery.
or premature separation of the placenta in late pregnancy, is indicated by abdominal pain and vaginal bleeding. Treatment
includes fetal monitoring, IV normal saline and packed red cells as needed.
is painless bleeding in late pregnancy. Because the placenta lies over the cervical os, a cesarean section may be required. Treatment:
fetal monitoring, IV normal saline and packed red cells are administered
results from uterine atony and sometimes fromretained fetal tissue. Treatment
consists of IV normal saline, packed red cells as needed and oxytocin or methylergonovine 0.2 mg IM to contract the uterus and control bleeding. Curettage is performed to remove retained tissue.
The Dialysis Patient
Hypotension during or after dialysis is frequently seen because of fluid loss. Treatment consists of placing the patient in the Trendelenburg position and giving a fluid challenge of 200 cc of normal saline.