Supine Hypotension Syndrome (Aortocaval Compression)
Pathophysiology & Risk Factors
The gravid uterus compresses the inferior vena cava and aorta when the patient is supine (especially >20 weeks). This reduces venous return, cardiac output and uterine perfusion.
- Risks: Late pregnancy, supine/sitting position, varicose veins
- Why a problem in ambulances? Stretchers and transport positions exacerbate compression.
Pre-hospital Management
- Left lateral tilt (15–30°) or manual left uterine displacement (LUD)
- Exaggerated Sims position for transport if tilt not possible
- High-flow oxygen, IV fluids if hypotensive
- Rapid transport – monitor maternal BP and fetal movements
Note: Efficacy of left lateral displacement confirmed since 1972; avoid full supine position at all costs.
Breech Presentation
Types & Incidence
Foetus lies longitudinally with buttocks in the lower pole of the uterus. Occurs in 3% of births.
| Type | Description | Incidence |
|---|---|---|
| Frank (extended legs) | Buttocks first, legs extended | 70% |
| Complete | Buttocks + flexed knees | ~10% |
| Footling | Foot/leg first | ~20% |
Pre-hospital Management – “Hands Off the Breech”
- Position mother sitting up or on back if imminent
- Allow spontaneous delivery of legs and torso
- Ensure back rotates uppermost
- Once axillae visible: Modified Mauriceau-Smellie-Veit (MSV) for head OR Lovset manoeuvre for arms (NSW Ambulance assisted shoulder protocol)
- Prepare for neonatal resuscitation
Never pull – hands-off unless arms/head need assistance.
Complications
- Fractures (humerus, clavicle), Erb’s palsy, intracranial haemorrhage, spinal damage, fetal hypoxia
Cord Prolapse
Pathophysiology & Red Flags
Umbilical cord lies in front of or beside presenting part after membrane rupture → cord compression → fetal hypoxia. TIME CRITICAL – ~9% perinatal mortality.
Indications: Sudden ROM + change in fetal movement or meconium.
Pre-hospital Management (Time-Critical)
- Knee-chest position (or exaggerated Sims for transport)
- Minimal cord handling – cover with warm saline/dry pad
- If cord pulsation stops and delivery NOT imminent: Push presenting part off cord (two fingers or mother-assisted)
- Continue manual relief until handover to obstetric team
- Rapid transport + pre-alert for emergency caesarean
- Prepare neonatal resuscitation
Note: Not standard NSW Ambulance guideline – requires patient consent and service authorisation.
Shoulder Dystocia
Recognition (“Turtle Sign”)
Head delivers but shoulders fail to follow. Anterior shoulder impacted behind pubic symphysis. EMERGENCY – fetal hypoxia develops rapidly.
HELPERR Mnemonic (NSW Ambulance aligned)
- H – Call for Help + time the head-to-body interval
- E – Episiotomy (if needed)
- L – Legs (McRoberts position + suprapubic pressure)
- P – Posterior arm delivery (Rubin or Woods screw)
- E – Enter (rotate shoulders 180°)
- R – Roll to all-fours (Gaskin manoeuvre)
- R – Remove (last resort – symphysiotomy/clavicle fracture in extremis)
Nuchal Cord
Management
Common (up to 30% of births). Gently check for loose loop after head delivery.
- Loose: Slip over head or shoulders
- Tight: Clamp and cut (only if delivery obstructed)
- Do NOT pull head – allow spontaneous delivery
Postpartum Haemorrhage (PPH)
4 T’s
- Tone (uterine atony – most common)
- Trauma (lacerations)
- Tissue (retained placenta)
- Thrombin (coagulopathy)
Pre-hospital Management
- Fundal massage + bimanual compression
- Oxytocin 10 IU IM (if per local protocol)
- IV fluids, oxygen, rapid transport
- Inspect placenta for completeness
Pre-eclampsia & Eclampsia
Classic Triad (after 20 weeks)
- Hypertension (≥140/90)
- Proteinuria
- Oedema / headache / visual changes
Management
- Magnesium sulfate for seizures (per protocol)
- Left lateral position, oxygen, urgent transport
- Avoid bright lights / stimulation
Antepartum Haemorrhage (Placenta Praevia / Abruptio)
Praevia vs Abruptio
| Praevia | Abruptio | |
|---|---|---|
| Pain | Painless | Severe abdominal pain |
| Bleeding | Bright red, visible | Dark, may be concealed |
| Uterus | Soft | Hard / woody |
Management (Post 24 weeks)
Do NOT perform vaginal exam. Left lateral, oxygen, large-bore IV, rapid transport to obstetric unit.
Uterine Inversion / Rupture
Inversion
Fundus protrudes through cervix. Replace immediately (Johnson manoeuvre) + oxytocin after replacement.
Rupture
Sudden severe pain, cessation of contractions, shock. Immediate laparotomy required – rapid transport.
Multiple Pregnancy
Key Risks
- Preterm labour, cord prolapse, malpresentation, PPH
Pre-hospital Care
Prepare for two (or more) resuscitations. Deliver each baby as normal, clamp cords separately, rapid transport for third-stage complications.