Case of the Month #9

Tarni Duhre

You are called urgently to A&E to assist with a patient who is 36 weeks pregnant with a low GCS. She collapsed in front of her husband after complaining of severe abdominal pain.

He reports she had been complaining of a headache and some epigastric pain for the preceding 24 hours. She is P3+1, 41 years old, obese, a smoker and has been treated for high blood pressure during her pregnancy.  On arrival her observations include:

  • SpO2 99% on 15L trauma mask 
  • HR 135bpm, BP 72/38, RR 28
  • GCS: E2, V2, M5.

What is your differential diagnosis? 

  • Pulmonary embolism  
    • (Leading cause of direct maternal deaths during or up to 6 weeks postpartum in the UK) 
  • Pre eclampsia  
  • Amniotic fluid embolism  
  • Haemorrhage – Including concealed e.g abruption, praevia, uterine rupture 
    • (Leading cause of maternal death worldwide) 
  • Cardiac disease  
    • (Leading cause of indirect maternal deaths in UK)
  • Sepsis  
  • Drug toxicity/overdose  
    • (Suicide is the leading cause of direct deaths occurring within a year of pregnancy in UK) 

On examination you find she is cool peripherally with increased capillary refill time. She has a tense, hard abdomen. A venous blood gas reveals Lactate 3.1, H+ 59, Hb 63.  

What is your immediate management? 

  • A-E assessment 
  • Ensure left lateral tilt/manual displacement of uterus and head down. 
  • Call for extra help early – midwife/obstetrician. Assess fetal wellbeing, but your main priority is the mother. 
  • Large bore IV access 
  • Fluid resuscitation 
  • Alert haematologist and organise blood products/major haemorrhage call 
  • Consider tranexamic acid 
  • If cardiac arrest, aim for uterine evacuation within 5 minutes. You may also need to deliver the fetus to control massive bleeding. 

How do physiological and anatomical changes in pregnancy impact resuscitation?  

  • Aortocaval compression 
    • From 20 weeks the gravid uterus reduces venous return in the supine position by up to 30-40% 
  • Respiratory  
    • Changes in lung function, diaphragmatic splinting, decreased Functional Residual Capacity and increased oxygen consumption make ventilation more difficult and hypoxia more rapid.  
  • Intubation 
    • Increased breast size, laryngeal odema and weight gain in pregnancy can make intubation more difficult. Along with an increased risk of aspiration due to a progesterone mediated decrease in Lower Oesophageal Sphincter tone and increased intra-abdominal pressure. 
  • Cardiovascular 
    • Increased plasma volume by up to 50% causes dilutional anaemia. Decreased Systemic Vascular Resistance and increased Heart Rate and Cardiac Output increases circulation demands. Uterine blood flow is approximately 10% of Cardiac Output at term resulting in potential for massive haemorrhage.  

This patient experienced a major placental abruption with associated severe concealed antepartum haemorrhage. She had risk factors including increasing age, smoking and pre-eclampsia. Following emergency delivery of the fetus to control bleeding she is taken to intensive care for ongoing management of hypovolaemic shock, coagulopathy and pre-eclampsia. 

What are the pathophysiological effects of pre-eclampsia? 

  • Cardiovascular 
    • Increased Systemic Vascular Resistance, reduced plasma volume, increased Left Ventricular work, Reduced Cardiac Output  
  • Respiratory 
    • Pulmonary odema 
  • Renal 
    • Reduced Glomerular Filtration Rate, Reduced urate clearance  
  • CNS 
    • Loss of cerebral blood flow autoregulation, cerebral odema, leading to seizures 
  • Hepatic 
    • Raised transaminases, peri-portal necrosis, subcapsular swelling and rupture 
  • Haematological 
    • Thrombocytopenia, coagulopathy, haemolysis  
  • Fetal 
    • Intra-Uterine Growth Restriction, premature delivery, placental abruption, intrauterine death 

What is the management of severe pre-eclampsia/eclampsia? 

  • Control BP, aim < 160/110 
    • Labetalol 
    • Nifedipine 
    • Hydralazine 
  • Give IV magnesium sulphate to severe pre-eclamptic women or those with seizures.  
  • Do not use diazepam, phenytoin or other anticonvulsants as alternatives 
  • Limit fluids to 80ml/hr, unless other ongoing losses 
  • Do not routinely use volume expansion 
  • As the pathophysiology is thought to be linked to the placenta, uncontrollable pre-eclampsia may require early delivery. However, symptoms may continue up to 24 hours post delivery.  

Take home messages 

  • Remember the key differences in resuscitation of pregnant women: physiological changes, left lateral tilt, potential benefit of early delivery.
  • Your primary concern is sustaining the life of the mother. 
  • Get multidisciplinary team involvement early. 
  • Pre-eclampsia can develop and progress even after delivery of the fetus. Magnesium for treatment of seizures

Further reading

RCOG Green-top Guideline No. 56: Maternal Collapse in Pregnancy and the Puerperium  

RCOG Green-top Guideline No. 63: Antepartum Haemorrhage

NG 133 Hypertension in pregnancy: diagnosis and management

MBRRACE-UK Update: Key messages from the UK and Ireland Confidential Enquiries into Maternal Death and Morbidity 2018