Post Partum Hemorrhage

District I ACOG Medical Student Teaching Module 2010

Post Partum Hemorrhage - Definition

Commonly defined as….

SVD > 500cc blood loss

C/S > 1000cc blood loss

*PPH generally refers to GA >20wks

Other Definitions

Hematocrit Change – defined as change > 10% but not useful in acute setting

Need for Transfusion – variable practiceHemodynamic stabilityTiming – early or lateSymptomatic

Relevance

One of top five causes of maternal mortality anywhere

#1 cause maternal mortality worldwideDeveloped countries 1/100 000 births

compared to 1/1000 births in developing countries

Incidence 5% - 10% deliveries (depends on defn)

Physiologic Adaptations of Pregnancy

plasma volume 40-50% RBC 20-30%

*in severe PIH - hemoconcentration

Normal Mechanism of Hemostasis

‘Living ligatures’ – Baskett 2000Intrinsic vasospasmLocal decidual hemostatic factors

including tissue factor & type 1 plasminogen activator inhibitor

clotting factors (except I and XI)

Zymogens of Serine Proteases

Activities

Factor XII binds to exposed collagen at site of vessel wall injury, activated by high-MW kininogen and kallikrein

Factor XI activated by factor XIIa

Factor IX activated by factor XIa in presence of Ca2+

Factor VII activated by thrombin in presence of Ca2+

Factor Xactivated on surface of activated platelets by tenase complex and by factor VIIa in presence of tissue factor and Ca2+

Factor II activated on surface of activated platelets by prothrombinase complex

Cofactors Activities

Factor VIII activated by thrombin; factor VIIIa is a cofactor in the activation of factor X by factor IXa

Factor V activated by thrombin; factor Va is a cofactor in the activation of prothrombin by factor Xa

Factor III (tissue factor) a subendothelial cell-surface glycoprotein that acts as a cofactor for factor VII

Fibrinogen Activity

Factor I cleaved by thrombin to form fibrin clot

Transglutaminase Activity

Factor XIII activated by thrombin in presence of Ca2+; stabilizes fibrin clot by covalent cross-linking

Regulatory and other proteins

Activities

von Willebrand factorassociated with subendothelial connective tissue; serves as a brigde between platelet glycoprotein GPIb/IX and collagen

Protein C activated to protein Ca by thrombin bound to thrombomodulin; then degrades factors VIIIa and Va

Protein S acts as a cofactor of protein C; both proteins contain gla residues

Thrombomodulin protein on the surface of endothelial cells; binds thrombin, which then activates protein C

Antithrombin III most important coagulation inhibitor, controls activities of thrombin, and factors IXa, Xa, XIa and XIIa

Blood Loss Estimation

All studies show gross underestimation of blood loss at delivery

Visual estimation especially unreliable for small and large amounts of blood loss

Prasertcheroensuk et al (2000)

- 228 women in 3rd stage

- >500cc : visual (5.7%) actual (27.63%)

- >1000cc: visual (.44%) actual (3.51%)

***Incidence underestimated 90%

Primary, Early or Acute PPH

Delivery - < 24h PP90% PPH casesAssociated with more bleeding

Secondary or Late PPH

24h – 12 weeks postpartumAffects 1-3% of all deliveriesCommon causes include: - infection

- RPOC

- Abnormal uterine involution

Etiology

4 T’s

-Tone

-Tissue

-Trauma

-Thrombin

Uterine Atony

75-90% PPHMostly associated with 10 PPH6% after c/sRisk factors after c/s incl multiples,

Hispanic ethnicity, induced/augmented labor, macrosomia, and chorioamnionitis

Tissue

Retained placenta 10% PPH cases10% placenta’s have fundal implantationPlacenta accreta 0.005% of all deliveries90% of accreta’s have PPH and 50% of

these have hyst

Trauma

10 cause PPH in 20% casesInjury to genital tract during delv OR 1.765% uterine inversions have PPH48% uterine inversions have bld

transfusion

Thrombin

1% cases of PPHKnown association with coagulation failure - abruption - PIH - sepsis - IUFD - incompatible blood - abortion

Risk Factors in PPHEtiology Process Clinical Risk Factors

Tone Overdistended Uterus Polyhydramnios, Multiple Gestation

Macrosomia

Uterine Muscle Fatigue Rapid Labor, Prolonged Labor

High Parity

Intra Amniotic Infection Fever, Prolonged ROM

Functional/Anatomic Distortion of the Uterus

Fibroid Uterus

Placenta Previa

Uterine Anomalies

Tissue Retained Products

Abnormal Placenta

Incomplete Placenta at Delivery

Previous Uterine Scar

High Parity

Retained Blood Clots Atonic Uterus

Trauma Lacerations Precipitous or Operative Delivery

Extensions at C/S Malposition, Deep Engagement

Uterine Rupture Previous Uterine Surgery

Uterine Inversion High Parity, Fundal Placenta

Thrombin Pre-existing Coagulopaties, Liver Disease

Acquired in Pregnancy ITP, DIC

Therapeutic Anti-coag History of clots

Factors Associated With PPH

Retained Placenta (OR 3.5)Failure to Progress 2nd Stage (OR 3.4)Placenta Accreta (OR 3.3)Lacerations (OR 2.4)Instrumental Delivery (OR 2.3)Large For GA Newborn (OR 1.9)Hypertensive Disorders (OR 1.7)Induction of Labor (OR 1.4)Augmentation of Labor With Oxytocin (OR 1.4)

Factors Associated With PPH

DM – 30-35% compared to 5-10%Inherited coagulopathies

– most common is VWB (1-3% prevalence)

- 70% have type 1 (↓ factor VIII, ↓ vW Ag,

↓ vW factor activity)

- risk PPH 22% with vWD & 18% hemophilia

Additional Risk Factors

Age > 35yAsian or Hispanic ethnicityObesityPost dates > 42 wksPrevious PPHPlacenta Previa

Key Management Issues

PreventionEarly RecognitionImmediate Appropriate Intervention

Blood Loss Signs & Symptoms

Blood Loss (%) Blood Pressure

Signs & Symptoms

500-1000ml (10-15) normal Palpitations, dizziness, tachycardia

1000-1500ml (15-25) Slightly low Weakness, sweating, tachycardia

1500-2000ml (25-35) 70-80 Restlessness, pallor, oliguria

2000-3000ml (35-45) 50-70 Collapse, air hunger, anuria

>2500cc blood loss – 50% mortality if not managed urgently & appropriately

Initial Management

ABC’sCall for helpMobilize team (staff, anesthesia, blood bank etc)IV accessFluid resuscitationExamine patient including fundal massage, dx

trauma/ inversion/ other etiologies, and fundal massage

Foley catheterBlood work (CBC, coag profile, cross match)Reverse coagulation abnormality

Uterotonic Medications

OxytocinErgotHemabateMisoprostolVasopressin

Drug Therapy For PPH

Drug Dose Side Effects ContraindicationsOxytocin 10 IU IM/IMM

5 IU iv bolus

10-40 IU/L

-Usually none

-ctx

-N&V

-water intoxication

-hypersensitivity

Ergot 0.25mg IM

0.125 mg IV

Q5mins X 5 doses

-peripheral vasospasm

-HTN

-N&V

-HTN

-peripheral disease

-Raynauld’s

-hypersensitivity

Hemabate

(PGF2α)

0.25 mg IM/IMM

Q15mins X 8 doses

-flushing

-diarrhea/N&V

-O2 desats

-bronchospasm

-restlessness

-hypersensitivity

-asthma

-active cardiac, pulmonary, renal, or hepatic disease

Misoprostol

(PGE1)

400-1000mcg PR/PV/PO X 1 dose

-pyrexia/flushing

-N&V/diarrhea

-abd pain

-HA

-hypersensitivity

-pregnancy

Vasopressin 20U/100ml saline

Inject 1ml at bleeding site

-acute HTN

-bronchospasm

-N&V/cramps

-HA, vertigo

-angina

-death if iv

-coronary artery disease

-hypersensitivity

Surgical Management

CurettageEmbolizationTamponade (Balloon, packing etc…)Compression suturesVessel ligationHysterectomy

Tamponade

Bakri Balloon

- Silicone balloon - 500cc capacityFoley catheter with 30cc balloonSengstaken-Blakemore BalloonVaginal packingSaline filled glove

B-Lynch Suture

Vessel Ligation

Vessel Ligation

Uterine - O’Leary Stitch

- Chromic 0 passed through lateral aspect of lower segment as close to cervix as possible and then through broad ligament lateral to vessels

Ovarian - distal to cornua by passing suture through myometrium medial to

vessels

Recombinant Activated Factor VIIa

Tx of bleeding disordersDose up to 120mcg/kg q2h until

hemostasisPromising but needs more studies$10,000/mgRisk thromboembolism

Step 1 – Initial Assessment

Resuscitation-Large bore iv’s-O2-Vitals-±foley catheter

Dx Etiology-explore uterus (tone/tissue)-explore genital tract (trauma)-review history (thrombin)-observe clots

Labs-CBC-coag profile-cross match

Step 2 – Directed Therapy

Tone-massage-compress-drugs

Tissue-manual removal-curettage

Trauma-correct inversion-repair laceration-identify rupture

Thrombin-reverse anticoagulation-replace factors

Step 3 – Intractable PPH

Get Help-OB/Surgery-Anesthesia-Lab/Blood Bank-ICU

Local Control-manual compression-±pack uterus-±vasopressin-±embolization

BP and Coagulation-crystalloids-blood products

Step 4 - Surgery

Repair Lacerations Ligate Vessels-uterines-ovarian-internal iliac

Hysterectomy

Step 5 – Post Hysterectomy Bleeding

Abdominal Packing Embolization

Secondary PPH

Generally less bleedingMostly related to infection or RPOCNo RCT’sAbx/uterotonics as appropriateEvacuation