Thursday, September 16, 2021

Postpartum Hemorrhage Case File

Posted By: Medical Group - 9/16/2021 Post Author : Medical Group Post Date : Thursday, September 16, 2021 Post Time : 9/16/2021
Postpartum Hemorrhage Case File
Eugene C. Toy, MD, Edward Yeomans, MD, Linda Fonseca, MD, Joseph M. Ernest, MD

Case 10
A 24-year-old G1P0 at 39 weeks’ gestation was admitted to the hospital for induction of labor secondary to Class A2 gestational diabetes. Diabetes was diagnosed at 28 weeks when all four values on a 3-hour oral glucose tolerance test were elevated. She was initially treated with glyburide, but due to persistent fasting hyperglycemia she was placed on a traditional split-mixed insulin regimen. The estimated fetal weight on admission was 3600 g and the cervix was long and closed. After three doses of misoprostol the examination had changed to fingertip and 50% effaced. A Foley catheter was inserted into the cervix and left in place for 12 hours. When it was removed, the cervix was 2 cm dilated and still 50% effaced. Presentation was confirmed by ultrasound to be vertex and oxytocin was initiated at 8 o’clock on hospital day 2. Membranes were artificially ruptured 12 hours later and over the next 8 hours, the patient reached complete dilation. After 3 hours of pushing, the fetal head delivered spontaneously. One minute later the shoulders were delivered with a combination of McRoberts maneuver and suprapubic pressure. There was a fourth-degree extension of her midline episiotomy. The infant had Apgar scores of 5 and 7 and weighed 4050 g. The placenta was manually extracted, following which the fundus was noted to be markedly atonic. Unusually heavy bleeding necessitated immediate measures to control. Estimated blood loss prior to treatment was 1000 mL.

➤ What is the diagnosis?
➤ What are the important precipitating factors?
➤ What are the primary and secondary measures that might be used to control bleeding?


ANSWER TO CASE 10:
Postpartum Hemorrhage

Summary: This is a primigravid woman with gestational diabetes who underwent medically indicated induction of labor. The induction was long, but did culminate in vaginal delivery. The delivery was complicated by heavy bleeding and a fourth-degree extension of a midline episiotomy.

Diagnosis: Postpartum hemorrhage.
Important precipitating factors: Uterine atony is by far the most important cause of postpartum hemorrhage. Risk factors for atony present in this case include induction of labor, prolonged labor, and possibly uterine overdistention by a large fetus. Other risk factors for atony not present in this case include polyhydramnios, multiple gestation, rapid labor, chorioamnionitis, and a history of atony with a previous delivery. Besides atony, there is the potential for retained products of conception after manual extraction of the placenta. Also, blood loss can be increased by bleeding from the episiotomy site.
Primary and secondary measures to control bleeding: These will be explained in greater detail in the clinical approach section that follows. Measures can be grouped as medical (compression, oxytocin, methylergonovine, other uterotonic agents), surgical (uterine compression sutures, vessel ligation, hysterectomy), and other (vessel embolization, packing).


ANALYSIS
Objectives
  1. Anticipate the likelihood of postpartum hemorrhage in light of risk factors present before delivery.
  2. Develop an organized approach to the management of postpartum hemorrhage.
  3. Outline appropriate blood volume replacement.

Considerations
In this chapter, the term “postpartum hemorrhage” is restricted to bleeding caused by and/or: uterine atony, genital tract lacerations, and retained products of conception (placenta or membranes). Uterine inversion, placenta accreta, and amniotic fluid embolism are uncommon obstetrical conditions that are associated with postpartum bleeding, but these conditions are not included in the discussion of postpartum hemorrhage in this chapter. Antepartum hemorrhage includes placental abruption, placenta previa, and most cases of rupture of both scarred and unscarred uteri, as well as causes of bleeding like abortion, ectopic, and hydatidiform mole that are most often encountered in the first trimester; all of these antepartum complications are likewise excluded from consideration here. The majority of cases of postpartum hemorrhage that complicate vaginal delivery can be managed medically. Disseminated intravascular coagulation (DIC) can incite bleeding de novo, but more often it enhances bleeding due to any of the conditions mentioned above. The possibility of DIC must be kept in mind by all obstetricians managing postpartum hemorrhage due to the three causes discussed in this chapter.


APPROACH TO
Postpartum Hemorrhage

DEFINITIONS

POSTPARTUM HEMORRHAGE (PPH): Several definitions are used in the literature (need for transfusion, drop in hematocrit more than 10%), but none are completely satisfactory.1 For ease of understanding, PPH is defined herein as estimated blood loss after vaginal delivery more than 500 cc or after cesarean delivery more than 1000 cc. Using these definitions the approximate incidence is 5%.

UTERINE ATONY: Failure of uterine smooth muscle fibers in the myometrium to contract after delivery. Normally myometrial contraction constricts the spiral arterioles supplying especially the placental bed, but with atony, this mechanism does not function properly. Because uterine blood flow at term is approximately 600 mL/min, atony can lead to rapid loss of a large volume of blood, eventually leading to hemorrhagic shock and death if not managed expeditiously.

DISSEMINATED INTRAVASCULAR COAGULATION (DIC): This diagnosis is suspected clinically when blood fails to clot, diffusely oozing from cut or raw surfaces and usually does not respond to surgical measures to control bleeding. The mechanism producing DIC may be either consumption of coagulation factors or dilution secondary to volume replacement with fluids that contain no coagulation factors, or often both. Laboratory indicators of DIC include three or more of the following: platelet count less than 100,000/mm3, increased prothrombin time, increased partial thromboplastin time, decreased fibrinogen, increased fibrin degradation products, or increased D-dimer (bearing in mind that pregnancy itself may falsely elevate D-dimer level).

CLINICAL APPROACH
Because of the inaccuracy of visual estimates of blood loss, the diagnosis of postpartum hemorrhage is often not identified until the patient develops hypovolemic shock. In other words, the early recognition of significant hemorrhage requires vigilance. Multiple investigators have shown that early recognition and intervention leads to better clinical outcomes including less transfusions, less need for surgical management, and less blood loss as determined by drop in hemoglobin. The identification of hypovolemia is a clinical diagnosis. Physician and nurse skill in patient volume assessment are important to facilitate timely intervention.

The most common etiology for postpartum hemorrhage is uterine atony, and risk factors2 have been well documented (Table 10–1). Hence, in those patients with multiple risk factors, the physician should be prepared for postpartum hemorrhage; nevertheless, serious hemorrhage often occurs in the absence of risk factors.

There are some investigators that promote active management of the third stage of labor to decrease the likelihood of PPH. Maneuvers such as massage of the uterus and judicious traction of the cord even prior to separation may enhance the onset of uterine contractions and decrease the incidence of uterine atony. These measures are certainly important in developing countries where pharmacological agents or blood products are not widely available. In the United States, active management of the third stage should be balanced against the possibility of uterine inversion.

Immediately after delivering the placenta the uterine fundus should be palpated through the abdominal wall. Assessment of vaginal bleeding and a systematic review of the clinical parameters for volume status are paramount at this stage. If the uterine fundus is soft and boggy, bimanual compression and a call for help should be initiated simultaneously. Oxytocin should be infused

Table 10–1 RISK FACTORS FOR UTERINE ATONY
 
Uterine overdistention
Multiple gestations
Polyhydramnios
Macrosomia
Grand multiparity
Abnormal labor
Rapid labor
Prolonged labor
Prolonged use of oxytocin
Chorioamnionitis
General anesthesia
Past history of postpartum hemorrhage



briskly intravenously and the situation should be reevaluated. If the uterus has not become firm, additional measures should be implemented. These may include placing another large-bore IV line, inserting a Foley catheter in the bladder, exploring the uterine cavity to rule out retained placenta or membranes, and inspecting for lacerations.3

The obstetrician should assess whether the vaginal bleeding is arising from the cervix, distal to the cervix, or above the level of the cervix. Pressure or ring forceps should be placed on lacerations if identified, but the operator continues to assess for further bleeding. In other words, sometimes patients will have significant uterine bleeding in addition to a cervical or vaginal laceration.

During the initial 2 to 3 minutes of postdelivery assessment, early postpartum atony or lacerations should be quickly identified and aggressively addressed. Rapid laboratory tests including hemoglobin, hematocrit, coagulation profile, and especially cross-matching blood are not critical at this juncture (see the section that follows on blood transfusion).

With persistent atony and ongoing bleeding, two other, interrelated considerations arise: which additional uterotonic agent(s) to try and whether to begin transfusing blood. In the absence of hypertension, Methergine (methylergonovine) 0.2 mg IM is a suitable choice and can be repeated once. 15-Methyl prostaglandin F2 alpha (Hemabate) 250 μg IM is usually tried next. There is no theoretical or practical advantage gained by intramyometrial injection. Up to eight doses can be given, but rarely is this done in practice. If one or two doses do not improve uterine tone and decrease bleeding, most obstetricians would take the next step in the algorithm. Moreover, Hemabate is expensive. Some investigators recommend the use of rectal (preferred) or oral misoprostol in doses up to 1000 μg, but the published experience is relatively small. Finally, if at the initial examination of the fundus it is found to be firm, the uterine cavity should be explored for retained products and the possibility of uterine rupture. The vagina and cervix should be carefully inspected for lacerations and, if found, appropriately repaired. Retained products and genital tract lacerations together contribute around 20% of cases of postpartum hemorrhage. The woman in the case presented had a fourth degree perineal laceration which likely added to her blood loss.

Decision to Transfuse
Adequate uterine perfusion is a requirement for delivery of all uterotonic agents to their site of action. Blood transfusion may therefore be required; transfusion may be chosen earlier in the management scheme if bleeding is very heavy or hypotension is present.

The decision to transfuse is a crucial one. Lack of recognition of hemorrhagic shock until late, delaying transfusion until the patient is hypotensive and suffering from tissue ischemia, is one of the leading reasons for maternal mortality. Yet, requesting blood products from the blood bank in unwarranted circumstances is costly, and can lead to unindicated transfusions. The issues that the obstetrician should take into account in deciding whether to transfuse include (1) patient’s starting hemoglobin level, (2) rapidity of the bleeding, (3) estimated blood loss and clinical volume status based on systematic assessment, (4) response to therapy, (5) etiology of bleeding and likelihood of remedy, and (6) availability of blood products and time required to obtain blood. There is no blood test or single parameter that gives the answer to the question: “Should this patient be transfused?” There is likely no other circumstance that relies more on physician judgment and training than the patient assessment, ongoing monitoring, and timely management of hemorrhage.

If packed red blood cells are to be given, transfusion may be started with either typed and screened or O-negative blood. Waiting for blood to be cross matched is not advisable for most cases of obstetrical hemorrhage and trying to anticipate which women may require transfusion and cross matching blood in advance is both impractical and costly. If multiple units of packed cells are transfused, for example with an estimated blood loss more than 2 L, it may be indicated to transfuse fresh frozen plasma (FFP) to ensure adequate coagulation factors are present to prevent dilutional DIC. FFP contains about 700 mg of fibrinogen in 250 mL. Cryoprecipitate contains 200 mg fibrinogen in 15 mL, but the need for multiple units would expose the recipient to many donors. A recent report from Parkland Hospital (Alexander et al)4 describes transfusion of whole blood (which obviously contains coagulation factors) for massive hemorrhage cases, but whole blood is not available at many centers.

If medical management of uterine atony fails, subsequent steps may be influenced by a woman’s desire for future fertility. When sterilization is requested, the threshold to proceed with hysterectomy in the setting of severe hemorrhage requiring transfusion is often lower.

Two nonsurgical options have been championed by a few investigators in the recent literature. The first is balloon tamponade5, with several different types of “balloons” recommended. Currently popular is the Bakri balloon which holds up to 500 cc, puts uniform pressure on the uterine cavity (possibly an improvement over the old method of packing the uterus with gauze), and allows for egress of blood through a channel in the middle of the balloon.

The second nonsurgical option is to have interventional radiology embolize the uterine arteries. This option is severely limited by the requirement for expertise and availability of radiology personnel. Until recently, the procedure was considered relatively safe. The report by Maassen et al6 cited in the references describes two significant complications related to the procedure: development of vesicovaginal fistula in one woman and migration of gelfoam particles to the external iliac artery compromising blood flow to the woman’s leg! Given that the entire series of women undergoing embolization numbered only 11, these two complications take on added significance.

Surgical Management
If medical management of uterine atony fails, subsequent steps may be influenced by a woman’s desire for future fertility. When sterilization is requested, the threshold to proceed with hysterectomy in the setting of severe hemorrhage requiring transfusion is often lower. Once the abdomen is open (for
example, at the time of cesarean delivery), the first step in surgical control of hemorrhage is bilateral uterine artery ligation. Next would be a compression suture like the B-Lynch stitch (see Figure 10–1) or multiple squares. An infrequent intervention could be administration of recombinant activated factor VII. This is only considered for very serious hemorrhage when other measures have failed. An appropriate dose is 90 μg/kg intravenously. The “court of last resort” is hysterectomy, which is described more fully in Case 6.

In conclusion, the approach to a woman with postpartum hemorrhage requires the implementation of a clinical algorithm that is well designed and carefully executed, analogous to the algorithm for managing shoulder dystocia.


Postpartum Hemorrhage

Figure 10–1. The B-lynch stitch is used to form an external compression of the
uterus using suture. (Reproduced, with permission, from DeCherney AH, Nathan L,
Goodwin TM, et al. Current Diagnosis & Treatment: Obstetrics & Gynecology. 10th ed.
New York,NY: McGraw-Hill; 2007:483.)


Keeping in mind that uterine blood flow is 600 cc/min, the management must also be expeditious. Contemporary obstetric practice requires immediate access to a blood bank. Postpartum hemorrhage remains one of the leading causes of maternal death, both nationally and worldwide.


Comprehension Questions

10.1 With regard to the management of postpartum hemorrhage, which of the following statements is true?
A. The most common and most effective route of administration of Hemabate (15-methyl prostaglandin F2 alpha) is intramyometrial.
B. Methergine (methylergonovine) is no longer indicated in an algorithm for managing uterine atony.
C. Uterine artery embolization involves negligible maternal morbidity.
D. Use of the Bakri balloon appears to be a reasonable step before resorting to hysterectomy for uterine atony.

10.2 Which of the following blood components contains the most fibrinogen per unit volume?
A. Packed red blood cells
B. Fresh frozen plasma (FFP)
C. Cryoprecipitate
D. Platelet concentrates

10.3 When all other reasonable measures to control hemorrhage have failed, what is the appropriate intravenous dose of recombinant activated factor VII to give to a woman weighing 70 kg?
A. 6 μg
B. 6 mg
C. 60 mg
D. 6 g


ANSWERS

10.1 D. The Bakri balloon, despite relatively few reported experiences, appears to be a good alternative to packing the uterus with gauze. In a woman who desires preservation of fertility, use of the balloon is a reasonable step before resorting to hysterectomy. As for the other choices, Hemabate is more commonly given intramuscularly, methylergonovine is only contraindicated if the patient is hypertensive, and there are serious risks reported with uterine artery embolization.

10.2 C. Cryoprecipitate contains 200 mg of fibrinogen in 15 mL. The next best answer, FFP, contains 700 mg in 250 mL.

10.3 B. This question requires a little arithmetic. The recommended dose of recombinant factor VIIA is 90 μg/kg. Multiplying by 70 gives a dose of 6300 μg or 6.3 mg. The other choices are obviously too little or too much.


Clinical Pearls

See US Preventive Services Task Force Study Quality levels of evidence in Case 1
➤ Whether at vaginal or cesarean delivery, the value of bimanual compression (not massage) is underemphasized. For vaginal delivery, the operator’s fist is placed in the anterior vaginal fornix and the abdominal hand folds the fundus forward. At cesarean delivery, a reasonably long (5-10 min) trial of bimanual compression should precede any attempt to place uterine compression sutures (B-Lynch). Such sutures will often prove unnecessary after pressure is released (Level III).
➤ If vaginal bleeding persists despite a well-contracted fundus,undiagnosed genital tract laceration (including uterine rupture) should be suspected. Thorough inspection of the birth canal, especially of the cervix, and manual exploration of the uterine cavity should be performed (Level II-3).
➤ In performing bilateral uterine artery ligation, the operator should take care not to place the stitch too low on the lower uterine segment, nor too wide into the broad ligament. Ureteral injury may result (Level II-2).
➤ When serious hemorrhage is encountered, and medical measures appear to be unsuccessful, keep in mind that drugs must be delivered to the site of action. Restoration of circulating blood volume is crucial (Level II-3).
➤ Peripartum hysterectomy for hemorrhage should not be undertaken unless the patient has been transfused first with blood. This advice is a corollary to the preceding pearl (Level III).

REFERENCES

1. Postpartum hemorrhage. ACOG Practice Bulletin. 2006;108:1039-1047. 

2. Sosa CG, Althabe F, Belizan JM, Buekens P. Risk factors for postpartum hemorrhage in vaginal deliveries in a Latin-American population. Obstet Gynecol. 2009; 113:1313-1319. 

3. Yeomans ER, Gilstrap LC. Postpartum hemorrhage. In: Gibbs RS, Karlan BY, Haney AF, Nygaard I (eds). Danforth’s Obstetrics and Gynecology. 10th ed. Philadelphia, PA: Lippincott Williams & Wilkins, 2008;452-461. 

4. Alexander JM, Sarode R, McIntire DD, Burner JD, Leveno KJ. Whole blood in the management of hypovolemia due to obstetric hemorrhage. Obstet Gynecol. 2009;113:1320-1326. 

5. Georgiou C. Balloon tamponade in the management of postpartum haemorrhage: a review. BJOG. 2009;116:748-757. 

6. Maassen M, Lambers M, Tutein Nolthenius R, van der Valk P, Elgersma O. Complications and failure of uterine artery embolization for intractable postpartum haemorrhage. BJOG. 2009;116:55-61.

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