You are called to see a 39 year old female driver in the Emergency Department who has been brought in by ambulance after a motor vehicle crash (head on collision). She is eight months pregnant (first pregnancy), and is complaining of abdominal pain.
(c) Please discuss the expected physiological changes associated with pregnancy and how they would impact on her management.
Multiple factors: consider the following:
Cardiovascular: vasodilated state with lower baseline BP, higher baseline HR, and higher cardiac output. Masking of initial hypovolaemia, risking foetal circulation, best monitored by foetal heart rate. Large intra-abdominal mass (uterus) puts patient at risk of supine hypotensive syndrome: need to displace uterus or position in left lateral position.
Respiratory: diagphragms pushed up, decreased FRC (need to insert ICCs higher); respiratory alkalosis (expected CO2 30, with HCO3 20): need to keep in mind when assessing blood gases and if ventilating patient. Swollen airway, larger breasts: intubation often difficult.
Gastrointestinal: decreased gastric emptying, and weakened lower oesophageal sphincter: increased risk of aspiration.
Haematological: hypercoagulable state, risk of Rh incompatibility with foetus: potential for Rhesus isoimmunisation.
Foetus: benefits from supplemental oxygen; avoid tetracyclines, quinalones, NSAIDs (premature ductal closure), etc.
The management of the pregnant poly-trauma patient is discussed elsewhere. The answer prepared for Question 3 from the first paper of 2007 is very similar: "Outline the special considerations involved in the care of a pregnant patient involved in multi-trauma.".
In summary:
Airway changes
Bag-mask ventilation becomes more difficult:
Laryngoscopy becomes more difficult:
Less time is available for intubation:
Intubation is more risky
Respiratory changes
Circulatory changes
Electrolyte and endocrine changes
Renal changes
Gastrointestinal and nutritional changes
Oh's Intensive Care manual: Chapter 64 (pp. 684) General obstetric emergencies by Winnie TP Wan and Tony Gin
Soar, Jasmeet, et al. "European Resuscitation Council Guidelines for Resuscitation 2010 Section 8. Cardiac arrest in special circumstances: Electrolyte abnormalities, poisoning, drowning, accidental hypothermia, hyperthermia, asthma, anaphylaxis, cardiac surgery, trauma, pregnancy, electrocution." Resuscitation 81.10 (2010): 1400-1433.
Mattox, Kenneth L., and Laura Goetzl. "Trauma in pregnancy." Critical care medicine 33.10 (2005): S385-S389.
DROST, THOMAS F., et al. "Major trauma in pregnant women: maternal/fetal outcome." Journal of Trauma-Injury, Infection, and Critical Care 30.5 (1990): 574-578.