Physiological Changes with Pregnancy
– Uterus gets 20-30% of cardiac output.
– Volume and RBC expansion begins about 4 wks, peaks at 28-34 weeks, declines to delivery.
– Larger relative increase in plasma volume vs RBCs –> decrease in HCT to nadir 24-26 weeks.
– Lower peripheral vascular resistance, increased cardiac output.
– Delayed gastric emptying –> more likely to have food in stomach!
– Increased minute ventilation, so increase in PaCO2 very worrisome!
– Airway w C-spine – protect C-spine and ensure patent airway, place definitive airway in secondary survey.
– Breathing – rescue breaths, supplemental O2 and ventilation in secondary survey.
– Circulation – chest compressions, IV access, volume resuscitation in secondary survey.
– Do chest compressions with pt rolled to maternal L side (off IVC), human wedge, or…
– Keep patient supine and manually displace uterus to the left – optimal chest compression vectors.
– D: Defibrillate (mono 360J, biphasic 200J) and DDx: ; consider DDx (Hs and Ts) in secondary survey.
The Four-Minute Rule: Due to the avidity of fetal hemoglobin, the fetus has about 2 minutes of O2 reserves in a pulseless and apneic mother. Consider perimortem C-section after 4 minutes of unsuccessful resuscitation IF:
– Fetus viable (>23-24 weeks) AND
– Facilities to care for premature/sick neonate available.
** Perimortem C-section not only can save baby – can lead to improved chances for mom!
Amniotic Fluid Embolism
– Sudden, catastrophic syndrome of cardiac, pulmonary and inflammatory pathophysiology.
– DDX: massive PE, septic shock, acute MI with cardiogenic shock, eclampsia, bilateral PTX, uterine rupture
Motor vehicle accident:
– Proper seatbelt use should be encouraged – reduces traumatic injury.
– MONITORING POST-MVA: Monitor for contractions if >20 weeks (above umbilicus):
– If < 3/hour, monitor for 4 hours then D/C home if stable.
– If > 3/hour, monitor for 24 hours.
– DISCHARGE IF: no ROM, reassuring FHT, contractions resolve, no VB or uterine tenderness.
Active Management of the Third Stage of Labor:
– Oxytocin – with or soon after delivery, PRIOR to placental separation (breastfeeding if oxytocin refused!)
– Early cord clamping
– Gentle, continuous tension on cord WITH BRANDT MANEUVER (to avoid inversion)
– Uterine massage after placenta delivers
Systematic Review: 7 trials, 8427 women – reduced risk of severe PPH (>1000mL, RR 0.34) and blood loss >500mL (RR 0.34), anemia after delivery, need for transfusion or need for uterotonics in first 24 hours. Active management associated with DBP >90 mmHg, increased afterpains and use of analgesia (RR 2.53) and increase return to hospital with bleeding (RR 2.51).
TREAT LIKE A TRAUMA: ABCs, 2 large-bore IV, check CBC, type & cross 4-6 units pRBC, IVF 2 L NS or LR.
– Oxytocin 10 units IV or IM, 10-40 units in 1L NS at 250 cc/h
– Methergine (methylergonovine) 0.2 mg IM (NOT IN HTN)
– Hemabate (prostaglandin F2a) 0.25 mg IM or intermyometrial q 15 mins x 8 doses
– Misoprostol 800-1000 mcg PV/PR or 600 mcg PO/SL
– Pelvic Interventions
– Uterine massage
– Empty bladder
– Four Ts
– Tone – uterine atony (70%) – drugs and massage
– Trauma – cervical and vaginal lacerations (20%), inversion or rupture
– Tissue – retained placenta – sweep
– Thrombin – coagulopathy (ITP, TTP, vWB, DIC) – consider FFP, platelets
– Go to surgery if bleeding persists!