Trauma in pregnancy and the ED delivery

1. Trauma in pregnancy and the ED delivery Rebecca Burton-MacLeod Oct 30, 2003

2. Background • Trauma in 6-7% of pregnancies • accounts for nearly half deaths in pregnancy (46.3%) • most commonly due to MVC (>50%), assault, fall

3. 10 physiological changes….[that exam question!] • Dec BP first trimester (dec sys 2-4mmHg, dec dias 5-15mmHg) • inc HR (by 10-15bpm) • CVP 4cm (instead of 7.5cm) • blood volume inc 48-58% • CO inc 40% • inc clotting factors • FRC dec by 20% • oxygen consumption inc by 15% • dec gastric motility • inc gastric acid production

4. 10 anatomical changes….[that other question!] • diaphragm rises 4cm with rib flaring resulting • inc size uterus • bladder displaced upwards • bowel displaced and modified peritoneal irritation signs • sympheseal distraction (7.7-7.9cm) • ureteral dilation • dec gastroesophageal sphincter response • supine hypotensive syndrome • blood flow to uterus inc 10x • inc peripheral venous pressure

5. Case • 28 y.o. female G1P0 30wks GA. MVC. Unconscious when arrives in ED. Sats 88%. Decreased A/E right side • Airway/breathing management…what considerations in pregnant patient?

6. Airway/Breathing • Oxygen promptly (dec oxygen reserve, inc consumption) • RSI (high risk of aspiration) • adjust mechanical respirators (inc TV) • Chest tube insertion 1-2 IC spaces above normal (raised diaphragm)

7. Case cont’d • Circulation issues in pregnancy? • High index of suspicion for shock (inc blood volume, but uterine blood flow compromised first) • avoid vasopressors, if possible (dec uterine blood flow even more) • use RL (more physiologic and less acidotic) • tilt pt 15-30 degrees, or elevate right hip

8. Secondary survey • Complete hx • obstetrical hx • physical exam • evaluating/monitoring fetus

9. Obstetrical hx • LMP • EDC • problems/complications of current pregnancy • problems/complications past pregnancies • determination of fetal GA (uterine size) • GA >24wks, wt >500gm (survival 20-30%)

10. Estimation of GA • Rough estimate--any fundus palpable above umbilicus is viable!

11. Physical exam • Rectal exam • pelvic exam: • speculum for signs of vaginal trauma, cervical dilation, source of vaginal fluid…do swabs for GBS, chlamydia/gonorrhea if leakage of amniotic fluid, slide for ferning of amniotic fluid • bimanual exam for bony pelvic trauma, advanced labour

12. Fetal evaluation • FHR and Fetal movement!!! • If <24wks then intermittent FHR monitoring • if >24wks then continuous external FHR monitoring

13. FHR strips • A--accelerations • B--baseline (120-160bpm), beat to beat variability (loss indicates fetal distress) • C--contractions • D--decelerations (late decels indicates fetal hypoxia)

14. FHR strips • Variability • Decelerations

15. Labs • Routine trauma bloodwork • blood type and Rh status • coagulation studies if abruption suspected • ABG for maternal hypoxia and acidosis

16. Imaging questions • What options exist for diagnostic imaging modalities?

17. Imaging options • Plain films • CT/MRI • U/S

18. Imaging questions • Any concerns with radiation exposure?

19. Radiography • Major effects of exposure to radiation for fetus: • congenital malformations (small risk b/w 2-15wks GA if rads>100 mrad) • growth retardation (15% risk of small head size) • postnatal neoplasia (0.2-0.8% for CT pelvis) • death(<1% during first 2wks after conception)

20. Low exposure group (<1 mrad): head c-spine s-spine extremities chest High exposure group: l-spine (204-1260 mrad) pelvis (190-357 mrad) hip (124-450 mrad) IVP (503-880 mrad) UCG (1500 mrad) KUB (200-503 mrad) Radiography exposure1000 mrad = 1 rad

21. Radiography • exposure of <5-10 rad causes no significant increases in fetal complications • take precautions--shield abdomen, focus beams • naturally occurring rad during 9mos is 50-100 mrad

22. CT scans • Head/chest CT-- <1 rad • abdo above uterus -- <3 rad • pelvic -- 3-9 rad • spiral CT reduce radiation exposure by 14-30% • fetal assessment--CT will NOT show fetal injury, but will show uterine rupture, placental separation, placental ischemia

23. U/S • Best modality for assessment of mother and fetus (GA, placental location, fetal demise) • sensitivity 83-88%, specificity 98-99% • similar ability to detect intraperitoneal fluid in pregnant pts as compared to non-pregnant • less sensitivity for evaluating kidneys / pancreas / bowel / biliary tree than CT • safe for fetus, therefore firstline imaging

24. Imaging questions • Will this affect what studies are ordered?

25. Imaging • Bottom line: radiation deemed necessary for maternal evaluation should not be withheld on basis of potential problems for fetus

26. Other procedures • Kleihauer-Betke test • FMH (8-30% after trauma) • complications--Rh sensitization, fetal anemia, fetal distress, or fetal death from exsanguination • acid elution on maternal blood--adult cells colourless, fetal cells purple; ratio calculated

27. Kleihauer-Betke test • only sensitive for over 5ml, but as little as 1ml can sensitize 70% of Rh neg mothers • thus, all Rh neg mothers should receive one 300 mcg Rhogam within 72h • KB test only done on pts at risk for massive FMH which would require more than one dose of Rhogam (>30ml FMH) • less than 1% trauma, and 3.1% major trauma pts • KB not necessary <16wk GA as circulating blood volume <30ml

28. Types of trauma • Blunt • penetrating • fetal injury • placental injury • uterine injury

29. Blunt trauma • MVC, abuse, falls • Seatbelt use--no belts inc fetal death 4.1x, 3-point belt best as long as positioned correctly • physical abuse--4-17% (perpetrator usually known to pt); only 3% of pts tell MD what happened • falls--2% of pts fall more than once during pregnancy

30. Penetrating trauma • Organs most likely involved if upper abdomen affected (dec order): sm bowel, liver, colon, stomach • uterus almost exclusively during third trimester (fetal injury 60-90%) • GSW--maternal mortality 7-9%, fetal mortality 70%

31. GSW: above uterus injuries require exploration laparotomy for uterine wounds Stab: if above uterus then operative intervention based on clinical findings/imaging results laparotomy for uterine wounds Penetrating trauma

32. Fetal injury • Leading causes fetal death: maternal death, maternal shock/hypoxia, placental abruption, direct fetal injury (intracranial hemorrhage, skull #)

33. Predictors fetal death: Higher Injury Severity Scores (ISS>25, 50% incidence fetal death) lower GCS lower admitting maternal pH low serum bicarbonate FHR <110 bpm Predictors preterm birth: ROM placental abruption not associated with abdo tenderness or uterine contractions Predictors of fetal death/preterm birth

34. Placental injury • Abruption occurs 2-4% minor trauma, 38% major trauma • can occur with no signs of inj to abdominal wall • s/s--vaginal bleeding, abdominal cramps, uterine tenderness, amniotic fluid leakage, maternal hypovolemia, or a change in FHR • also associated uterine contractions--if less than 1/10min then unlikely abruption • U/S only accurate in <50% of cases • best indicator--fetal distress (60% of cases), thus FHR monitoring immediately

35. Abruption • If mother/fetus stable--expectant mgmt if <32wk GA, otherwise, C/S delivery recommended • 54x more likely to have coagulopathies if abruption • DIC directly proportional to amount of abruption

36. Uterine injury • 27y.o. 33wk GA had fall. Presents with contractions. Cx long, hard, posterior. • Use of tocolytics indicated? • Not routinely as 90% stop spontaneously and those that do not are often pathological in origin and tocolytics contraindicated

37. Uterine rupture • Caused by severe MVC, penetrating injuries • s/s--maternal shock, abdominal pain, easily palpable fetal anatomy, fetal demise • mgmt--either suture tear or hysterectomy

38. Disposition

39. Mother/fetus stable • Minimum 4h continuous FHR monitoring • if >3 uterine contractions/hour, persistent uterine tenderness, abnormal FHR strip, vaginal bleeding, ROM, any serious maternal injury (ejections, motorcycle/ped collisions, no seatbelts) = 24h minimum monitoring • all pts settled and d/c within 24h had live births!

40. Monitoring • One survey showed FHR monitoring often does not take place during first hour of maternal work-up (68%) • in survey only 15% of departments had adequate FHR monitoring equipment • often inadequate FHR monitoring despite fact fetal distress without overt clinical signs!

41. Mother stable/ fetus unstable • If GA >24wks and FHR unstable = C/S stat • If FHR present and GA >26wks then 75% survive • other indications for C/S--uterine rupture, fetal malpresentation during premature labor, and uterus mechanically limits maternal repair

42. Mother unstable/ fetus unstable • 32y.o. 30wk GA by dates. MVC. P110, BP 80/45. FHR 72. Splenic rupture. Which first--operative splenic mgmt or C/S? • Mother before fetus! • Repair of injuries that are life/limb saving for mother first • then if fetus still viable, consider C/S

43. Maternal arrest/ fetus unstable • Within 4min of maternal arrest, if no response to advanced cardiac life support consider perimortem C/S • Potential for fetal and maternal survival • No MD in US ever found liable for performing perimortem C/S • GA >24wks by best estimate • 70% of fetus that survive are delivered within 5min of ED arrival • 4min for maternal resuscitation, 1min for C/S!!

44. Perimortem C/S • Call for help (obs, peds) • continue CPR during procedure, consider thoracotomy with OCM • midline vertical incision from epigastrium to symphysis pubis through all layers to peritoneal cavity, using large scalpel • vertical incision through anterior uterus from fundus to bladder reflection, using large scalpel/scissors; if bladder encountered, rupture • if placenta encountered on opening uterus, it should be incised to reach fetus • clamp and cut cord after delivery of fetus

45. ED deliveries • ED suboptimal location • Consider transfer if in periphery and pt not in active labour • Call for obstetrical help if available • Perinatal mortality 8-10% for ED deliveries • ED selected by pts with complications (hemorrhage, PROM, eclampsia, PTL, abruptions, precipitous delivery, psychosocial complicating factors)

46. Stages of labour

47. First stage • Latent phase—slow cx dilation up to 4cm • Active phase—rapid dilation • Lasts 8h in primip, 5h in multip • Examine cx for effacement, dilation, position, station, presentation

48. Second stage • Full dilation of cx and urge to push with contractions • 50min primip, 20min multip • FHR monitoring and U/S useful—viability, lie, presentation

49. Delivery • Equipment:Sterile gloves, Towels, Cord clamps (2), Hemostats, Placenta basin, Surgical scissors, Rubber bulb syringe, Neonatal airways, Syringes, needles (small gauge), Gauze sponges • Lithotomy position • Once crowning, finger sweep to ensure cord not wrapped around neck • Modified Ritgen manoeuver used for delivery of head

50. Delivery cont’d • Suction nares/mouth • Downward traction on head for delivery of anterior shoulder • Upward pull subsequently will allow posterior shoulder to pass • Clamp cord and cut