Postpartum haemorrhage lacks a standard defintion and most of the international guidelines disagree on basic elemsnts of its management. Most of the time, people define in in terms of volume, that being 500ml in the 24 hours following delivery.  Standard peripartum management should include some uterotonic, be it oxytocin, ergometrin or misoprostol. Management of PPH starts with these drugs, moves on to add tranexamic acid and massive 1:1:1 transfusion (maybe even Factor VIIa) and continues through to mechanical compression strategies such as balloon tamponade. Ultimately, definitive management techniques can range from angioembolisation and "stepwise uterine devascularisation" by ligation and finally hysterectomy.

Question 17 from the second paper of 2017 was the first time anybody ever got asked about postpartum haemorrhage in the CICM exam. The examiners wanted to know about the advantages and disadvantages of all the various methods of controlling it. The next time this topic emerged was Question 17 from the second paper of 2018, where the focus shifted to causes and management. Fortunately, with at least one past paper SAQ raising awareness of the candidates, the pass rate had improved from 40.8% to 67.2%.

As far as published sources go, Chapter 24 from Oh's Manual ("General obstetric emergencies") by Winnie TP Wan and Tony Gin has a brief blurb on "severe obstetric haemorrhage" which offers a short introduction to the subject. What's there is probably not enough to answer Question 17 up to the level of a passing grade. Therefore, even the time-poor candidate will need to read widely. The most comprehensive recent review is probably by the WHO (Recommendations for the prevention and treatment of postpartum haemorrhage, 2012). That's over 40 pages for two SAQs, which does not seem to be a favourable marks-per-effort ratio. A shorter article by Mousa et al (2014) list many treatments, but do not go deeply into the advantages and disadvantages, which basically also fails to answer the question. Weeks (2015) wrote a nice review which does discuss the pros and cons, but fails to cover everything.  Unfortunately the author of this summary has had to compile this table of advantages and disadvantages without any one specific reference to recommend to the candidates. 

Definition of postpartum haemorrhage

Traditionally, it is the loss of more than 500ml of blood in the 24 hours following delivery. Pretty much nobody agrees with this traditional WHO definition, because:

• PV blood losses are usually underestimated
• None of the authors can seem to agree on the exact volume cutoff.
• There does not seem to be any scientific reason to limit the time frame to 24 hours
• The blood loss during a caesarian can often exceed this defined volume (some have proposed 1000ml blood loss as the cutoff)

Dahlke et al (2015) looked at four international guidelines and found that they each had a different definition of PPH. The more disturbing variation was in the recommendations for things like balloon tamponade and hysterectomy, where there were no clear guidelines in the guidelines. Each statement made different recommendations on the basis of the same evidence.

Causes of postpartum haemorrhage

The college answer to Question 17 from the second paper of 2018 recommends to classify the possible causes in the "4 T's" tone, trauma, tissue and thrombin, where:

• Tone: uterine atony 
• Trauma: surgery or injury
• Tissue: retained tissue (placenta) and/or membranes  
• Thrombin: any coagulation defect.

That may represent the minimum expected of a hastily scribbled CICM SAQ answer. For those playing at home (eg. doing these SAQs under exam conditions), some hasty scribbles may not match the college model answer, yet still remain accurate. In those cases it would help to have a  broader range of causes.

Thus:

• Uterine atony
  • Prolonged labor
  • Polyhydramnios
  • Multiple gestations
  • Chorioamnionitis
  • Oxytocin augmentation of labor
• Peripartum uterine trauma
  • Instrumental delivery
  • Surgical mishap
  • Laceration during labour (including episiotomy)
  • Uterine rupture
• Postpartum retained products
  • Placenta 
  • Membranes
• Coagulopathy
  • DIC
  • Amniotic fluid embolism
  • Sepsis 
  • Intrauterine foetal demise
  • HELP
  • Massive transfusion
• Placental abnormality
  • Placenta previa
  • Placental abruption

At some stage, the college may ask for a list of risk factors. One such list is provided by Sheiner et al (2005); this specifically refers to early PPH (i.e. within 24 hours of delivery):

• Retained placenta
• Failure to progress, 2nd stage
• Placenta accreta or praevia
• Lacerations
• Instrumental deliveries
• Large neonate for gestational age
• Hypertensive disorders
• Induction of labor
• Oxytocin augmentation

For extra credit, the trainees were expected to mention the WOMAN trial (Shakur et al, 2017). Bleeding PPH patients were randomised to receive 1g of tranexamic acid (and another 1g if needed). A whopping 20,060 patients were enrolled. The difference in death from haemorrhage was 1.5% vs 1.9%, in favour of tranexamic acid by 0.4% of absolute risk reduction - a difference which only achieved statistical significance because the numbers were massive and because the sample size was increased by 5000 patients mid-study. The number needed to treat are 267. 

Structured management of postpartum haemorrhage

This structure and a lot of the components are borrowed from the RANZCOG statement C-Obs 43.

Resuscitation

• A: either secure the airway if unprotected,  or prepare to do so with appropriate expertise (i.e. get an anaesthetist)
• B: preoxygenate with high flow oxygen
• C: establish IV access and give a fluid bolus; avoid hypothermia and use fluid warmers
• D: reassure patient and ensure analgesia is adequate
• E: correct ionised calcium (essential component of clotting); corrrect acidosis
• F: monitor fluid resuscitation efficacy by observing urine output
• G: fast the patient in preparation for surgery
• H: correct coagulopathy and commence transfusion
  • Activate massive transfusion protocol: the college answer to Question 17 from the second paper of 2018 mentions the National Blood Authority's obstetric guidelines, which are endoresed by CICM. The guidelines recommend:
    • FFP: 15 mL/kg
    • platelets: 1 adult therapeutic dose
    • cryoprecipitate: 3–4 g
  • Fibrinogen is all-important- the same NBA guidelines recommend a fibrinogen level of > 2.0 as a therapeutic  target
  • Tranexamic acid is also known to be beneficial (WOMAN trial -Shakur et al, 2017) - to be given within 3 hours of haemorrhage
• I: antibiotics are not routinely indicated for primary PPH outside of the scenario of septic abortion or endometritis. 

Specific management

• Uterine massage
• Bimanual compression
• Manual aortic compression
• Oxytocin
• Ergometrine
• Carboprost
• Misoprostol
• Gause pack or balloon tamponade
• Angioembolisation
• Brace sutures
• Ligation of the uterine artery
• Hysterectomy