Little Adult: A child with a grown up problem Interesting Case Rounds March 8, 2007 James Huffman Emergency Medicine Resident, PGY-1

Objectives β-hCG review Travsvaginal Ultrasound review Characteristics of the tests (urine/serum) Interpretation of results Travsvaginal Ultrasound review Role Logistics of ordering

Case 0037h 0120h Triage: 16♀ with low abdo pain, N/V, Vag bleed Pediatrician: Abdo pain x 6days w/ vomiting, no diarrhea Vaginal bleeding – light flow/spotting x 4-5 days LMP: ended 9/52 ago Postitive home preg test 2/52 ago

Case On Exam: Looks well Eyes N, Ears N, Throat N Chest: good A/E, CVS N Abdo: soft/mildly tender RLQ, No invol guarding, no mass, no organomegally “Her belly was as soft as a cucumber. Well, a rotten one”.

Case Booked for Abdominal U/S ?Miscarriage vs Gastroenteritis CBC: N U/A: cloudy with few epithelial cells, nil else Urine β-hCG: Neg, SG=1.020 (N ≤ 1.030) Serum β-hCG: <2 (N 0-5) Booked for Abdominal U/S ?Miscarriage vs Gastroenteritis

Case – return visit 1505h 38.3, 126/59, 82, 18, 96% On Exam: ↑RLQ pain, ↓nausea, vaginal bleeding stopped Denies passing clots/tissue On Exam: Minimal distress, moves easily Exquisitely tender RLQ, +invol guarding, +Rovsing’s sign Vaginal exam deferred as no bleeding currently

Case – return visit Abdo U/S: Repeat Labs: No signs of inflammation Appendix not seen Ovaries N Repeat Labs: No changes from previous LFTs N, Lipase N

Quick summary 16♀ with mild fever, RLQ pain, ?early signs of peritoneal irritation and vaginal bleeding Backgroud of positive home preg test 2/52 ago (now neg urine and serum x2) Normal labs and nil acute seen on abdominal U/S

DDx Inevitable/incomplete abortion Dysfunctional uterine bleeding Ruptured ovarian cyst PID Endometritis Appendicitis Mesenteric adenitis Early UTI (Ectopic pregnancy)

Case Transferred to FMC for TV ultrasound/pelvic exam Pt left without being seen. Saw WIC, vaginal swabs done:  Negative, as per pt Out patient TV ultrasound done Wednesday:  Results pending

Pregnancy Tests!? But this is a children’s hospital!

Trivia Youngest person to give birth? Lina Medina 5 years, 7 months Peru 1939

β-hCG Glycoprotein consisting of 2 linked subunits α-subunit is similar in shape to LH, FSH and TSH No studies specifically looking at pediatric pts Home Pregnancy Tests: Introduced in 1975 Immunometric assay of hCG in the urine Sensitivities vary, but 97% of pregnancies are picked up by 1/52 after first day of missed menses

β-hCG Limitations of urine testing: Sensitivity is affected by timing/user characteristics Elevated lipids, high Ig levels and low serum protein can interfere with results Dilute urine raises the threshold for hCG detection (CHR recommends SG ≥ 1.020) False positives occur with nonviable intrauterine pregnancy, ectopic, gestational trophoblastic disease and some ovarian tumours

β-hCG - serum Serum hCG levels rise soon after implantation (7-11 days after ovulation) Doubling time is 29-53 hrs for days 1-30 Rule of thumb: 10 IU/L @ time of missed menses 100 000 IU/L @ 10 weeks (peak) 10 000 IU/L @ term *Range is large – hCG levels should not be used for dates

β-hCG - serum Low levels suggest: Higher than expected levels suggest: Ectopic, abortion, (wrong dates) Higher than expected levels suggest: Multiple gestation, molar pregnancy, trisomy 21, some ovarian tumors, (wrong dates)

Ultrasound Discriminatory Zone: The hCG titer at which an intrauterine sac can be seen with transvaginal (TV) ultrasound CHR – 1200-1500 mIU/L (4-5 weeks) Abdo U/S – 6500mIU/L (6-8 weeks) TV ultrasound has become the gold standard for non-surgical diagnosis of ectopic pregnancy If hCG is above DZ level and IUP is not visualized on TVUS, liklihood of ectopic is >90% (*multiple gestation)

Ultrasound Logistics: The ACH diagnostic imaging department does not perform TV ultrasound Foothills will, however, they will not directly accept patients Therefore, you will need to transfer your pt to the FMC ED and have a physician there order the study

Take Home Points Obstetrical problems not isolated to adult realm Home pregnancy tests are reasonably sensitive by 1/52 after first day of missed menses, and false positives are rare Rule of thumb for serum hCG levels Transvaginal ultrasound if hCG levels are not what are expected for dates