Abdominal Pain OSCE - Ectopic Pregnancy

Case Overview

• Age/Sex: 29-year-old female
• Occupation: Office administrator
• Setting: Emergency Department (walk-in via ambulance after collapse at work)
• Chief complaint: "Severe lower abdominal pain"

Patient Script

Who I Am

I'm 29, I work in an office doing admin, and I live alone in a flat nearby.

What Brings Me In

I came because I've had really bad tummy pain since this afternoon and I felt faint twice at work.

My Story

It started suddenly about 4 hours ago with a sharp, stabbing pain in my lower belly on the left side. I'd had mild crampy pains off and on for 2 days before that. I noticed some light spotting yesterday and my period is 6 weeks late — I haven't had a period in about six weeks. This afternoon the pain got much worse, I felt sweaty and dizzy, and I fainted once briefly when standing up; my colleague called an ambulance. I also feel a bit sick and I have a pain under my left shoulder when I take deep breaths. I had some indigestion after a spicy takeaway last night but this pain is nothing like that — it's much worse and sharp. I have an old scar from an appendectomy when I was a teen but that hasn't bothered me for years.

My Medical Background

• Past medical history: treated chlamydia infection about 4 years ago; appendectomy at age 16
• Medications: none regularly, took ibuprofen at home earlier today
• Allergies: none known
• Social: smokes about 5 cigarettes/day, drinks socially (about 4 units/week), works long hours and under stress
• Obstetric/gynecologic: LMP about 6 weeks ago (normally regular 28–30 day cycles); no previous pregnancies; inconsistent condom use with a new partner for ~3 months

What I Think & Worry About

• I think maybe it could be something I ate or a pulled muscle from yoga I started last week.
• I'm really worried I might be having a miscarriage or something that could make me pass out again.
• I expect you to check me over quickly, stop the pain, and tell me if I need an operation or if this can be treated another way.

If You Ask Me About Other Symptoms...

• Vaginal bleeding: "Just light spotting since yesterday, not a heavy flow like a period."
• Nausea/vomiting: "I feel a bit sick but haven't vomited."
• Urinary symptoms: "No burning or change when I pee."
• Bowel: "I had some constipation last week but nothing today."
• Fever/chills: "No fever, but I felt clammy when I fainted."
• Contraception/sexual: "I haven't been using a reliable method — condoms sometimes; new partner about 3 months."
• Previous similar pain: "I've had painful periods before but this is much worse and on one side."
• Medications/treatments tried: "I took ibuprofen an hour ago but it didn’t help."

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Clinical Summary

Examination

• General: pale, diaphoretic, appears anxious
• Vital signs: HR 120 bpm (tachycardic), BP 90/60 mmHg (borderline low), RR 22/min, SpO2 98% on air, Temp 36.7°C
• Abdominal: lower abdominal tenderness greatest on the left; guarding and rebound in the left lower quadrant; mild abdominal distension
• Pelvic: vaginal bleeding noted in the vault; cervical motion tenderness; left adnexal tenderness to bimanual exam; small, tender adnexal fullness palpable on the left
• Other: mild shoulder-tip pain on inspiration (left), capillary refill slightly delayed

Investigations

• Urine pregnancy test: positive (pregnant)
• Serum beta-hCG: 1,800 IU/L (below or around the ultrasound discriminatory zone; lower than expected for an intrauterine pregnancy at 6 weeks)
• Full blood count: Hb 9.0 g/dL (low — suggests blood loss), WBC 14 x10^9/L (mild leukocytosis), platelets 260 x10^9/L
• Blood group and Rh: pending (send urgently) (needed for anti-D if indicated)
• Serum electrolytes & creatinine: Na 138 mmol/L, K 4.0 mmol/L, creatinine 70 µmol/L (renal function acceptable)
• Crossmatch: 2 units packed RBCs ordered (pending)
• Transvaginal pelvic ultrasound: no intrauterine gestation identified; complex adnexal mass on the left measuring ~3.5 cm consistent with likely ectopic; moderate free fluid in the pouch of Douglas and peritoneal cavity (suggests intraperitoneal bleeding)

Diagnosis

• Primary diagnosis: Ruptured left tubal ectopic pregnancy

  • Evidence: positive pregnancy test with missed period 6 weeks, sudden severe unilateral lower abdominal pain, vaginal spotting, hemodynamic instability (tachycardia, hypotension), shoulder-tip pain, transvaginal ultrasound showing no intrauterine pregnancy, left adnexal complex mass, and moderate free intraperitoneal fluid; falling hemoglobin suggesting significant bleeding.

• Important differentials to consider:

  • Ruptured ovarian cyst (can cause acute pain and free fluid) — less likely given positive pregnancy test and adnexal complex mass consistent with ectopic.
  • Threatened/complete/incomplete miscarriage of an intrauterine pregnancy — ultrasound shows no intrauterine pregnancy and adnexal findings point away from this.
  • Acute appendicitis — typically right-sided pain, less likely to cause positive pregnancy test findings or adnexal mass and large free fluid volume.
  • Pelvic inflammatory disease with tubo-ovarian abscess — usually febrile, more subacute, and not associated with a positive pregnancy test.

Management

• Immediate resuscitation: establish two large-bore peripheral IV lines; start aggressive IV crystalloid boluses while preparing blood products.
• Urgent gynaecology/obstetrics review and transfer to theatre: this presentation is consistent with a ruptured ectopic and requires emergency surgical management (laparotomy or laparoscopy depending on instability and local resources) — likely salpingostomy or salpingectomy.
• Transfusion: crossmatched blood ready; transfuse as indicated (Hb 9.0 with ongoing hemodynamic instability and ongoing bleeding) per institutional protocol.
• Analgesia and antiemetic: IV opioid analgesia titrated to effect; ondansetron PRN.
• Investigations/actions: urgent bedside focused transvaginal ultrasound if not already done; continuous monitoring of vital signs; send urgent blood group for Rh status and give anti-D immunoglobulin if patient is Rh-negative.
• Antibiotics: not routinely required for isolated ectopic rupture unless contamination suspected; give per local perioperative guidelines if surgical intervention planned.
• Consent and counselling: explain likely diagnosis, need for emergency surgery, risks (blood transfusion, fertility considerations), offer psychological support and contact for partner/next of kin; arrange postoperative contraception counselling and STI screening.
• Documentation: record events, bleeding, informed consent, and discuss plans with the patient and family in clear, empathetic language.

Key Learning Points

• Always perform a pregnancy test in any woman of childbearing age with abdominal pain — this is critical and can change immediate management.
• Correlate beta-hCG levels with transvaginal ultrasound findings: absence of an intrauterine pregnancy with an adnexal mass and free fluid in a woman with pain and vaginal bleeding strongly suggests an ectopic pregnancy, and haemodynamic instability implies possible rupture requiring urgent surgical intervention.
• Rapid resuscitation (ABC), prompt gynaecology involvement, blood typing/crossmatch, and preparation for operative management are priorities in suspected ruptured ectopic pregnancy.