Average blood loss following a vaginal delivery is about 500 cc.
Bleeding that is significantly in excess of that is considered post partum hemorrhage.
Most cases of post partum hemorrhage are caused by the uterus not contracting firmly after delivery. In some cases, there is a mechanical obstruction to the uterus contracting, such as
- Retained blood clot inside the uterus which disallows a firm, tight contraction, or
- Retained placenta.
Manually expressing the blood clot by squeezing the fundus will usually control bleeding from this source, and uterine exploration with manual removal of any remaining placenta will resolve that problem.
For most cases of relative uterine atony, uterine massage is an immediate, simple, and often very effective treatment to stop the bleeding. Uterotonic agents can be added:
- Oxytocin 20 units in 1 liter of IV fluids, run briskly (wide open) for a few minutes will flood the mother with a strong uterotonic agent.
- Oxytocin 10 units IM will take longer to be effective, but will have a more sustained action and is immediately available without an IV.
- Methylergonovine maleate 0.2 mg IV or IM will firmly contract the uterus, but should be used cautiously if at all in women with pre-existing hypertension.
- Prostaglandin F-2-alpha.
Bimanual compression of the uterus is another effective way of slowing or stopping the bleeding associated with post partum hemorrhage.
The uterus is elevated out of the pelvis by the vaginal hand, and compressed against the back of the pubic bone by the abdominal hand.
This places the uterine arteries on stretch and kinks them, decreasing the blood flow to the uterus.
The direct compression of the uterus limits circulation through the placenta to the placental site.
In forward military settings, packing the uterus and/or vagina with gauze may be effective in stopping the bleeding, can buy some time for other resuscitative or MEDEVAC efforts to be successful, and can be accomplished by those with limited obstetrical experience.
To pack the vagina:
- Use some form of speculum or retractors to open the vagina.
- Use a long object (ring forceps, dressing forceps) to push gauze sponge material into the upper vagina. Usually, this is gauze tape, but any roller gauze can be used. If roller gauze is not available, open a bunch of 4 x 4’s and tie them end to end.
- The initial layers of gauze are placed somewhat loosely, but subsequent layers are packed relatively tightly.
- This packing is continued until the vagina is totally filled with a relatively tight packing of gauze (a mass about the size of a 16-inch softball.
A Foley catheter should be placed in the vagina as these women will not be able to urinate with the packing in place.
Control pain with narcotics. This will also slow the bowels (good in this situation, because with the vaginal packing in place, she won’t be able to move her bowels).
Leave the packing for several days, then remove it. The bleeding will usually not start up again.
This works for several reasons:
- The pelvic mass created by the packing elevates the uterus up and out of the pelvis, placing the uterine arteries on stretch and decreasing their perfusion pressure.
- The tight packing exerts direct pressure on at least some branches of the uterine arteries, decreasing blood flow to the uterus.
- By disallowing the escape of uterine blood loss out the vagina, the packing contributes to a back-up pressure that helps tamponade uterine bleeding.
- If there are any vaginal or cervical lacerations contributing to the postpartum hemorrhage, the vaginal packing exerts direct pressure on those lacerations to stop the bleeding.
Uterine packing may also be undertaken, but requires more obstetrical skills, and is only a little more helpful than vaginal packing. This packing is placed inside the uterine cavity in an attempt to apply direct pressure to the bleeding placental site. After uterine packing is completed, vaginal packing is usually also done, and it is probably the vaginal packing that is doing most of the hemostatic work.
Those with access to a Bakri Balloon and training in its’ use can successfully deploy it in this situation.
Blood Transfusion
In a non-pregnant patient, progressive hypovolemia is usually accompanied by the predictable signs of tachycardia, hypotension and tachypnea before confusion and loss of consciousness occur.
Women with immediate post partum hemorrhage do not necessarily follow that path and may look surprisingly well until they collapse.
Because of this, your decision to give or not give blood to these women should depend more on your estimated blood loss, clinical circumstances and likelihood of continuing blood loss, and less on her vital signs. Women who quickly lose half their blood volume (2500 out of 5000 ml) usually benefit from transfusion.
Elevating the patient’s legs will drain the pooled blood from them back into the general circulation. In a pregnant patient, this could amount to as much as 1 unit of blood that you have functionally added back into her system.
In civilian settings, banked blood is usually given. In many operational settings, standard blood banking procedures may not be applicable or available. In these cases, direct donor to victim transfusion can be life-saving.
Use a donor with O negative blood (“Universal Donor”). Don’t try to match, for example, a B+ victim to a B+ donor. While the accuracy of blood type records has improved, there is still a significant inaccuracy rate (as high as 5%) in the medical record laboratory reports, identification cards, and dog tags. If you try to match a B+ victim to a B+ donor (type-specific blood transfusion), you are twice taking a 5% risk of a mismatch. It is safer to take that risk only once. If the only available blood for a Rh negative victim is Rh positive blood, Rhogam may be used, in very large doses of 25-30, full-size, 300 microgram ampoules, IV, per unit of blood, to neutralize the Rh sensitizing effects of the Rh positive blood.
Arrange IV tubing so that there is a large-bore needle at each end. This is facilitated by use of a 3-way stopcock. If this is not available, you can simply cut off the tubing at the end and insert it into the hub of a needle. Sterile petroleum jelly can provide a seal and the needle is held tightly to the IV tubing with adhesive tape.
Position the donor about 3 feet higher than the victim. With the victim in a lower bunk, the donor would be in an upper bunk. With the victim on the floor or on the deck, the donor would be on a cot or packing crate.
Insert the IV into the donor and let the blood flow downhill through the tube until it reaches the other end. Clamp the tubing just long enough to insert the other end into the victims IV or vein.
Unclamp the tubing and allow time for about 1 unit (500 cc) of blood to flow into the victim. The exact amount of time would depend on the caliber of the tubing and needle, length of the tubing, height of the donor above the victim and doubtless other factors. In practice, allow about 10 minutes, but be prepared to stop it earlier if the donor becomes light-headed or dizzy.
Because fresh, whole blood has better oxygen-carrying capacity than banked units of packed RBCs, and it is prewarmed, and because it contains platelets, clotting factors and serum proteins, each unit has about twice the clinical impact of a unit of packed cells from the bank. If, based on your clinical experience, you believe a patient would benefit from two units of PRBCs from a blood bank, they will generally do well with a single unit of fresh, whole blood.
Medical Evacuation
After the patient is transferred to a definitive care facility, it will be easier for them to identify the true, native blood type (major and minor blood groups) if they have a sample of blood taken from the patient prior to any transfusions. If time permits and the tactical situation allows for it, try to draw a single red-topped tube of the victim’s blood prior to transfusion that you can send along with the MEDEVAC for use by blood banks further up the line.