Postpartum Haemorrhage Flashcards
Definition of primary postpartum haemorrhage (PPH)
The most common form of major obstetric haemorrhage. Defined as the loss of 500l or more blood from the genital tract within 24 hours of giving birth. In women with lower body mass (less than 60Kg), a lower level of blood loss may be clinically significant.
Definition of primary postpartum haemorrhage (PPH)
The most common form of major obstetric haemorrhage. Defined as the loss of 500ml or more blood from the genital tract within 24 hours of giving birth. In women with lower body mass (less than 60Kg), a lower level of blood loss may be clinically significant.
How can PPH be classified
- Minor PPH (500-1000ml)
- Major PPH (more than 1000ml), which can be further subdivided as moderate (1001-2000ml) and severe (more than 2000ml).
- Secondary PPH- abnormal or excessive bleeding from the birth canal between 24hours and 12 weeks postnatally.
- Obstetric haemorrhage remains one of the major causes of maternal death in both developed and developing countries (13 deaths in the UK per year)
Causes of PPH
- Tone (uterine atony- the most common cause of PPH)
- Trauma (e.g perineal tear)
- Tissue (retained placenta)
- Thrombin (bleeding disorder)
Risk factors for PPH
-
Tone- Multiple pregnancy, previous PPH, Foetal macrosomia, Failure to progress in second stage, Prolonged third stage of labour, general anaesthesia, fever, prolonged ROM
Generally, atony results from over distension of the uterus (macrosmoia, polyhydramnios etc.), intra-amniotic infection, muscle fatigue from delivery - Tissue- Retained placental tissue, blood clots, placenta accreta
- Trauma- Placental laceration, episiotomy,
- Thrombin- Pre-eclampsia, gestational thrombocytopenia, HELLP, pre-existing (haemophilia, ITP, VWD)
How should women with risk factors for PPH be managed
Should only be delivered in a hospital with a blood bank on site. Additionally antenatal anaemia should be investigated and treated appropriately as this may reduce morbidity associated with PPH.
Pathophysiology of atony
- The uterus is a muscular organ which contracts during labour for dilatation and effacement of the cervix.
- After delivery, the myometrium continues to contract. This squeezes down on the placental arteries at the point of attachment to the uterine wall and clamps the arteries shut and reduces uterine bleeding.
- These contractions normally continue for a few weeks following delivery. However, in uterine atony, the myometrium fails to contract after delivery leading to excessive bleeding
Presentation of PPH
- Women may present with anxiety, thirst, nausea, cold and pain
- Additional signs include rising fundus, peritonism, reduced urine output, tachycardia, tachypnoea, narrow pulse pressure.
How can PPH be prevented
- Antenatal anaemia should be investigated and treated appropriately as this may reduce the morbidity associated with PPH
- Uterine massage is of NO BENEFIT in the prophylaxis of PPH
- Prophylactic uterotonics (10IU oxytocin IM) should be routinely offered in the management of the third stage of labour, especially those with risk factors for PPH.
- For women delivered by C-section, 5IU by slow IV injection should be used to encourage uterine contraction and decrease blood loss
- Ergometrine-oxytocin may be used in the absence of HTN in women at increased risk of haemorrhage since it reduces the amount of minor PPH.
- Should consider the use of IV tranexamic acid (0.5-1.0g), in addition to oxytocin at caesarean section
How can postpartum blood loss be estimated
Visual estimation of PPH is inaccurate and often underestimates blood loss. Clinical signs and symptoms should be used in combination with visual estimation (signs of hypovolaemia are less sensitive in pregnancy)
* In pregnancy, pulse and blood pressure are usually maintained in the normal range until blood loss exceeds 1000 ml;
* Tachycardia, tachypnoea and a slight recordable fall in systolic blood pressure occur with blood loss of 1000–1500 ml
* A systolic blood pressure below 80 mmHg, associated with worsening tachycardia, tachypnoea and altered mental state, usually indicates a PPH in excess of 1500 ml
When should the MDT be alerted to PPH
When women presents with minor PPH (500-1000ml) without clinical shock
Measures for minor PPH
- Intravenous access (one 14-gauge cannula)
- Urgent venepuncture for: group and save, FBC, coagulation screen, including fibrinogen
- Pulse, respiratory rate and blood pressure recording every 15 minutes
- Commence warmed crystalloid infusion
Measures for major PPH
- ABCDE assessment- A high concentration of oxygen (10-15L) should be administered, regardless of maternal saturation
- Position the patient flat
- Keep the woman warm and transfuse as soon as possible, if clinically required (group O, RhD-negative, K-negative units)
- Until blood is available- Infuse up to 3.5L of warmed clear fluids, initially 2L of warmed isotonic crystalloid
When should FFP be administered in PPH
- If prothrombin time (PT) or activated partial thromboplastin time (APTT) are prolonged (more than 1.5x) and haemorrhage is ongoing, administer 12–15 ml/kg of FFP.
- If haemorrhage continues after 4 units of red blood cells (RBCs) and haemostatic tests are unavailable, administer 4 units of FFP
When should platelet concentrates be given in PPH
Administer 1 pool of platelets if haemorrhage is ongoing and platelet count less than 75
Causes and risk factors for the four Ts
Summary of management of PPH
