Obstetric emergencies

Classification of Caesarean sections according to urgency

Category 1    Requiring immediate delivery - A threat to maternal or foetal life

Category 2    Requiring urgent delivery – Maternal or foetal compromise that is not immediately life-threatening.

Category 3    Requiring early delivery – But no maternal or foetal compromise.

Category 4    Elective delivery – At a time suited to the woman and maternity staff.

Category 1 sections should be delivered within 15 minutes and category 2 sections within 30 minutes.

From a medico-legal point of view, meticulous attention to chronological documentation is essential. It is important to record the time you were called, the category given by the obstetrician, the time of delivery and the reasons for any delays.


Category 1, Caesarean sections represent an immediate threat to maternal or foetal life.
Some examples of possible causes are listed below:

1. Major haemorrhage
2. Profound and persistent foetal bradycardia
3. Prolapsed cord
4. Shoulder dystocia
5. Uterine rupture

Massive obstetric haemorrhage

Massive obstetric haemorrhage is a major cause of maternal death and morbidity. It is variably defined as: blood loss >1500 ml; a decrease in haemoglobin >4 g/dl; or acute transfusion requirements >4 units.
The gravid uterus receives up to 12 % of the cardiac output, thus obstetric haemorrhage can be unexpected and rapidly become life threatening.

Classification of Obstetric haemorrhage:

Antepartum haemorrhage (APH)
This is bleeding after 24 weeks gestation and before delivery.

Causes include:
Placental abruption
Placenta praevia 
Trauma
Uterine rupture

Primary postpartum haemorrhage (PPH)
This is defined as blood loss within 24 hours of delivery, which is >500 ml following a vaginal delivery and >1000 ml following a Caesarean section.

Causes include:
Uterine atony
Retained products of conception
Genital tract trauma
Clotting defects
Inverted uterus

Secondary postpartum haemorrhage
This is blood loss greater than 24 hours after delivery.

Causes include:
Retained products of conception
Puerperal sepsis 

AnaesthesiaUK - Emergency treatment of massive obstetric haemorrhage

References:

[i] CEMACH - Haemorrhage

[ii] SCOTTISH OBSTETRIC GUIDELINES AND AUDIT PROJECT: The Management of Postpartum Haemorrhage

[iii] BJACEACCP - Massive haemorrhage in pregnancy

[iv] Emergency Caesarean section: best practice; Review article; D. M. Levy; Anaesthesia Volume 61 Page 786 - August 2006