Specialist level OSCE answers and discussion

Chapter 6 Specialist level OSCE answers and discussion

MRANZCOG OSCE E

E1

Q1

History

• 26-year-old woman, nulliparous

• End-stage renal failure at 18 years old secondary to reflux nephropathy

• Was on haemodialysis until 23 years of age, when she received a kidney transplant from her brother

• Transplant has been reasonably successful over the last 2 years (1 episode of attempted rejection averted 3 years ago)

• Serum creatinine stable at 130 μmol/L

• Current immunosuppressive regime: Prednisolone, Azathioprine (ceased mycophenelate 18 months ago)

• Mild hypertension, controlled with atenolol

• No urinary tract infections last 12 months

• Periods 28–32 days apart, not heavy or painful; was amenorrhoeic until 6 months after transplant

• No past gynaecological history of note; uses condoms for contraception

• Last Pap smear 3 years ago, normal

• Not on folate/Elevit; has not had rubella checked

• Medical history: nil apart from above

• Surgical history: Re-implantation of ureters at 6 years old (only partially successful)

• Renal transplant surgery 3 years ago

• No family history of note

• Social Hx: Married 2 years ago, good relationship, wish to try for a baby soon

• Non-smoker, non-drinker, works in retail

Q2

• No change to the history

• On examination, BP 120/85, otherwise unchanged

• As long as she understands the potential risks to herself and her baby, she may start trying

Q4

Examination

• Drowsy, BP 170/110, urinalysis ++++protein

• Abdominal Ex: SFH=19 cm; fetal heart heard (150 bpm)

• Vaginal Ex: closed, long cervix

Investigation/management

• Transfer to labour ward for hydralazine to control BP, and close observation

• IV access, and send off bloods:

– FBE Hb 75, WCC 12.0, platelets 38

– U+E+Cr creatinine 260 μmol/L

– LFTs ALT 460, AST 320, ALP 50, albumin 30

• Patient is developing HELLP syndrome complicating severe pre-eclampsia

• She requires immediate delivery by caesarean section (likely to need classical C/S: will necessitate elective LUSCS for any future pregnancies)

• Contact haematologist – need platelets and 4–6 units of blood

• Will need general anaesthetic (not safe for spinal anaesthetic, due to thrombocytopaenia)

• Fetus is unlikely to survive given severe IUGR and severe prematurity – must counsel patient with sensitivity regarding this

• Needs hydrocortisone/steroid cover during caesarean section (long-term prednisolone)

• Will need close monitoring of renal function after delivery, in case of further decline (involve renal team)

20 marks total

Discussion

This case requires the candidate to display a knowledge of appropriate pre-pregnancy counselling for a renal transplant patient, as well as the management of pregnancy in such a patient. Two of the most common complications in renal transplant patients are pre-eclampsia (more common in transplant patients where there is renal impairment or pre-existing hypertension, of which this patient has both), and intra-uterine growth retardation.

The candidate should be able to assess the patient in Q4 to discover severe pre-eclampsia, complicated by HELLP syndrome. The fetus must be delivered due to overwhelming risk to the mother, despite the likelihood of fetal demise. This is an emergency situation, but must still be dealt with tactfully/sensitively when counselling the mother.

E2

Encounter 1

History

• Mrs M, 62 years old

• Periods ceased at 54 years old, never used hormone therapy

• Has had several episodes of irregular vaginal bleeding over the last 3 months

• G3P3, 3 NVDs, 6 grandchildren

• Last Pap smear last year, no history of abnormal Pap smears; mammogram last year normal (has them at around same time as Pap smears)

• Hypertension, takes 2 antihypertensives (unsure what tablets she takes)

• Type 2 diabetes, treated with metformin, BSLs not well controlled. Her GP is considering changing her to insulin

• Past surgery: laparoscopic cholecystectomy, appendicectomy, right total knee joint replacement

• Strong family history of cardiovascular disease and diabetes

• Non-smoker, non-drinker; lives with her husband and loves to look after her grandchildren

• NKA medications: antihypertensives and metformin

Encounter 3

There is an abnormally thickened endometrium for a postmenopausal woman (it should be </= 5 mm). This means that we need to perform a hysteroscopy and endometrial curettage for pathological diagnosis.

• Endometrial hyperplasia/carcinoma needs to be ruled out.

• The hysteroscopy uses either fluid or CO₂ gas to distend the potential endometrial cavity. The cavity is examined for irregular features or a polyp. Curettings are taken for histopathology and any polyps are removed.

• Risks of surgery: anaesthetic risks, infection, bleeding, perforation of the uterus (0.5%), gas embolism (rare, and only if CO₂ gas used).

Prior to surgery, will need a physician review with regards to the cardiovascular risk and diabetes. Needs a cholesterol/triglyceride check.

HbA1C is elevated at 10%. This means that for the previous 10 weeks the average glucose level was 13 mmol/L. The blood sugar levels need to be reviewed by a physician with a view to starting the patient on insulin therapy.

Serum creatinine is elevated, and need to consider diabetic renal damage (check 24-hour creatinine clearance and 24-hour protein excretion).

The patient is obese, and weight control by diet and exercise needs to be considered to decrease the associated health risks.

Discussion

This represents a straightforward case of endometrial carcinoma, with the complication of obesity and poorly controlled diabetes in the patient. Diabetes and obesity are both risk factors for endometrial carcinoma.

An examination candidate at specialist level would be expected to perform well at this station.

E3

Encounter 1

The history and examination should be brief in this station (labour ward emergency).

Examination

• BP 140/80, PR 100, T 37˚C

• Term fundus, no head palpable above the pelvic brim

• VE – fully dilated, cephalic, position OA, station 1 cm below ischial spines, moderate moulding, some caput, some descent with pushing

• The candidate is expected to perform immediate delivery of the baby due to fetal distress and prolonged second stage. If a vacuum/ventouse is asked for, it is not available/broken.

PROMPT: “Please describe how you would perform a Neville-Barnes forceps delivery.”

N.B. For both this part (performance of forceps) and station 2 (Mx of shoulder dystocia) some examinations may involve a model so that the manoeuvres can be physically demonstrated to the examiner.

• Call for assistance (senior midwife), to assess for contractions (already determined in Hx/Ex: adequate station and position, no head above the brim)

Some candidates may request a trial of forceps in the operating theatre (acceptable)

• Place patient in lithotomy, in stirrups

• Empty bladder

• Adequate analgesia: pudendal nerve block

• Apply first the left, then the right blade of the forceps, with obstetric cream for lubrication, inserting between contractions

• Check positioning of the blades – posterior fontanelle should be midway between the forcep blades

• Exert gentle traction in direction of the birth canal during contractions, with a maximum of three pulls/contractions. If undelivered after three pulls, failed instrumental delivery and requires immediate emergency caesarean section

• Extension of head after occiput passes under the symphysis

• Perform right mediolateral episiotomy once the head is on the perineum

Encounter 2

The candidate is expected to run through the management of shoulder dystocia.

The baby will be delivered in good condition at the point that the candidate removes the posterior arm – until then, if the candidate asks, the baby remains undelivered.

• Call for additional help (most experienced midwifery and obstetric staff available)

• One midwife to commence documentation and call out timing at regular intervals

• Stop patient pushing

• Move patient’s buttocks to the edge of the bed (bladder already empty, and episiotomy already cut from forceps delivery)

• Perform McRobert’s manoeuvre (extreme flexion/abduction of the maternal hips)

• Supra-pubic pressure downward and lateral for up to 30 seconds (Rubin I)

Encounter 4

The patient is distressed due to her baby’s injury. The candidate should explain the following points in a sensitive manner:

• The injury is due to stretching of the nerves of the brachial plexus during the delivery. Without effecting timely delivery of the baby, far worse injury to the baby (e.g. hypoxic brain injury) may have resulted.

• The nerve injury may take up to 6–12 months to fully resolve. However, in more than 90% of cases there is no permanent injury.

• The paediatric team will be involved in assessment/management of the baby.

• The main issue for any further pregnancies is the appropriate mode of delivery.

• The risk of shoulder dystocia in the next pregnancy is increased compared with the general population (1–16% recurrence).

The options for the patient include:

• caesarean section for future pregnancies

• attempted vaginal birth, if estimated fetal weight by ultrasound at 36/40 gestation is <4 kg. Emergency caesarean section if intrapartum risk factors for recurrent shoulder dystocia are present (e.g. slow progress of labour, need for induction of labour). Experienced accoucher to be present at the birth.

Either option is reasonable.

20 marks total

Discussion

This station must be conducted in such a fashion as to simulate the urgency of the real-life labour ward emergencies represented.

For encounter 1, if a ventouse/vacuum is the preferred method of instrumental delivery the examiner may allow the description of a vacuum delivery. In this case, the management is the same as for forceps delivery, except:

• optimal cup placement is 3 cm anterior to the posterior fontanelle (in OA position), placed between contractions

• a check is made that no maternal tissues or vaginal wall are trapped between the cup and the baby’s head

• pressure of the vacuum is gradually increased to –0.8 kg/cm²

• once ‘chignon’ has developed (wait 1–2 minutes) traction is applied at right angles to fetal head, with one hand pulling the vacuum device and the other inside the introitus with one finger on the fetal head and one on the cup to monitor force of contraction and anticipate cup detachment

• again, allow only three pulls during three separate contractions

• it is not always necessary to cut an episiotomy with a vacuum delivery.

For the management described in encounter 2, the ‘HELPERR’ mnemonic from the Advanced Life Support in Obstetrics course may be useful:

H – Call for help

E – Evaluate for episiotomy

L – Legs (McRoberts)

P – Suprapubic pressure

E – Enter manoeuvres (internal manoeuvres)

R – Remove posterior arm

R – Roll the patient (all-fours position)

Shoulder dystocia occurs in approximately 0.6% of births, with the majority of cases not having any predisposing risk factors (e.g. fetal macrosomia, maternal diabetes, PHx shoulder dystocia, prolonged first or second stage labour, maternal obesity). All labour ward staff should reasonably be expected to know how to manage this obstetric emergency well.

Although in this case the shoulder is delivered after removal of the posterior arm, if this manoeuvre had failed the further courses of action would include repeating the internal manoeuvres with the patient rolled from the lithotomy position onto all-fours, and then manoeuvres of last resort. Manoeuvres of last resort include (in no particular order):

• Zavanelli manoeuvre – pushing the fetal head back into the birth canal and performing a caesarean section

• cleidotomy – deliberate fetal clavicular fracture by upward pressure on mid-portion

• general anaesthesia – to relax uterine muscle

• maternal symphysiotomy – dividing the maternal symphysis after a local anaesthetic.

In encounter 3, the initial management of a transfusion reaction is expected from the candidate.

In encounter 4, the candidate is expected to show concern for the mother’s fears regarding the brachial plexus injury, and to gently reassure with the information in the above answer. Any reasonable approach, emphasising patient choice after carefully imparting the appropriate information regarding risk of recurrence, is acceptable. The authors accept that different approaches to mode of delivery may be employed in different obstetric units.

E4

Encounter 1

History

• Married for 5 years and ceased using the combined oral contraceptive pill 5 years ago in order to become pregnant

• 28 years old and nulliparous

• Has 28–30 day cycles and the periods last 4 days with primary dysmenorrhoea

• Her last Pap smear was 1 year ago

• No past gynaecological history of note. No past STDs/PID

• He is 28 years old and has never fathered any children

• No injuries/surgery to testes. No STDs. No past history of mumps orchitis

• Both healthy with no other personal history of note

• Sex 2–3 times a week, occasional dyspareunia

• They have no family history of note

• Non-smokers and occasionally drink alcohol. She is taking folic acid supplementation at a dose of 1 mg/day

• She is a primary school teacher and he is a secondary school teacher

• They are both very frustrated and anxious about their inability to become pregnant

Discussion

The candidate is expected to take a relevant history from both partners, to examine both partners, to discuss the diagnostic tests for infertility and discuss relevant treatment options, given the aetiology of the infertility.

Principles of both surgery for severe endometriosis, as well as IVF treatment are assessed in this OSCE.

E5

Encounter 1

History

• Mrs M, currently 36 weeks pregnant

• 3 previous pregnancies (6-year-old daughter, 4-year-old and 2-year-old sons)

• All deliveries were by caesarean section. The first was at 28 weeks with a breech presentation and an APH. The second two were elective and uncomplicated

• This pregnancy, persistent bleeding beginning at 23 weeks’ gestation. Mrs M has been an in-patient since 23 weeks, with small vaginal blood-loss 2–3 times per week since her admission. No large bleeds

• No gestational diabetes or hypertension during this pregnancy

• Medical problems: mild asthma

• Surgical Hx: appendicectomy at 14 y.o. (open, not ruptured)

• Allergic to penicillin (facial swelling and shortness of breath)

• Interior designer, husband is a builder; supportive parents, with mother and father currently staying to help look after the 3 children at home

Encounter 2

• Urea, electrolytes and creatinine

• Urinalysis – looking for blood suggestive of bladder invasion

• Coagulation profile

• Group and hold, cross-match of minimum 4 units of blood

• Ultrasound of uterus + placental site

• MRI of uterus and placental site (N.B. Although often ordered, the role of MRI in diagnosing/managing placenta percreta is still to be determined)

Encounter 3

• Could leave the placenta in situ and treat the patient with methotrexate.

• Could perform arterial embolisation following delivery.

Encounter 4

1. Divide the pelvic peritoneum parallel to the infundibulopelvic ligament to enter the retroperitoneal space.

2. Identify the external iliac artery and vein laterally, and the ureter medially.

3. Retract the ureter medially to expose the common iliac artery.

4. Identify the internal iliac artery as it branches from the common iliac artery.

5. Expose the internal iliac artery. Identify the internal iliac vein as it runs below the artery.

6. Ligate it distal to the posterior division, either by:

– using a right angle clamp to divide the tissue between the internal iliac artery and the internal iliac vein and pass a ligature around the artery. Secure this.

– a surgical clip may be applied across the artery.

7. Care must be taken to avoid damage to the internal iliac vein.

8. Before ligating the internal iliac artery re-identify the external iliac vessels and the ureter to ensure the correct vessel is ligated.

Discussion

With rising caesarean section rates, the numbers of cases of placenta accreta, increta and percreta have also risen. The highest risk of placenta percreta is in a woman with multiple previous caesarean sections and an anterior low-lying placenta over the area of the previous scar. In such patients it is necessary to have a high index of suspicion, so that appropriate investigations and management are carried out. If suspected, transfer the patient to a tertiary obstetric hospital with appropriately experienced surgeons, should it occur.

E6

Encounter 1

History

• Mrs B, 80 years old

• Vulval pruritis for the last 30 years

• Her local doctor has prescribed Canesten cream, Ovestin cream, and a mild corticosteroid cream at various times, but none of these treatments have worked. He has never examined her.

• More recently, Mrs B has noticed bleeding from the vulva on and off, and “I can feel a lump”. Bleeding is only with wiping, and associated with the lump.

• G7P4, 4 NVDs, 3 miscarriages, 10 grandchildren, 2 greatgrandchildren

• Menopause at 50 years old, no hormone therapy used

• No postmenopausal bleeding until the past 4 months

• She has never had a Pap smear, but has regular mammograms (last one last year, normal)

• No past surgical history

• Hypertension, treated with Atenolol 50 mg oral daily, well controlled

• No family history of note

• Non-smoker; drinks a glass of brandy each night before dinner, sometimes a glass of wine

• Lives with her 82-year-old husband, both fit and well, still drives, opens her bowels once per week, plays bingo on Thursday evenings

Encounter 4

The patient needs to be referred to a gynaecological oncologist for definitive management.

Encounter 5

The patient is referred because data shows that overall survival is improved with management by a gynaecological oncologist, as this is an uncommon gynaecological malignancy.

Management will be wide local excision, with 1 cm skin margins around the tumour and deep excision of tissue to the level of the deep fascia.

It is a lateral lesion, so right groin node dissection is necessary, OR sentinel lymph node procedure. (The candidate should be aware of the use of sentinel lymph node biopsy in vulvar cancer.)

Discussion

This patient presents with a stage II vulval SCC (tumour confined to the vulva/perineum, > 2 cm diameter, with no clinical evidence of groin node involvement). The prognosis, if treated appropriately with a gynaecological oncologist, is good, with an overall 5-year survival of 70–80%.

The candidate is expected to be aware of recent literature regarding use of sentinel lymph node dissection in the treatment of early stage vulvar cancer (Van der Zee et al. 2008). It has been reported that using radioactive tracer and blue dye to identify the sentinel groin node, groin dissection can be limited to the sentinel node only in stage I–II vulvar cancer. If the node is negative, no further groin node dissection is necessary, reducing the incidence of serious post-operative complications associated with extensive groin node dissection.

The lichen sclerosus that Mrs B has suffered from is a risk factor for the development of vulval SCC.

Reference

Van der Zee A G J, Oonk M H, De Hullu J A et al 2008 Sentinel node dissection is safe in the treatment of early-stage vulval cancer. Journal of Clinical Oncology 26:884–889

E7

Encounter 1

History

• 25 years old

• Menarche 14 years

• Regular periods until 2 years ago. Periods were every 28–30 days, lasting 5 days with no problems. For the past 2 years periods increasingly irregular, every 3–4 months and now no period for 6 months. Periods now last 5 days but often can have light bleeding for weeks at a time

• Single, sexually active for 5 years. Using condoms. Pap smear normal 6 months ago

• Acne as a teenager and has recurred in the past 2 years. Using cosmetic measures which are not helping

• Hirsutism on chin (plucks hair), around nipples (no treatment), on abdomen (waxes) and waxes legs every week. Problem has occurred over the past 2 years and is causing embarrassment. Some hair loss, which is mild, occurring on scalp generally

• No voice deepening, change to body shape, clitoral enlargement

• Now size 20. Started to gain weight 2 years ago (20 kg total weight gain). No exercise and eats poorly

• No past history – medical or surgical

• Mother has type II diabetes, father has hypertension

• No allergies, no medications, non-smoker, occasional alcohol

Investigations

• FSH, LH, prolactin, testosterone, DHEAS, TSH and/or FAI, SHBG

• Pelvic ultrasound

Encounter 3

The GTT is normal and will need repeating in 2 years.

The lipid profile is abnormal (increased LDL/HDL ratio) and will need repeating in 6–12 months once lifestyle changes have occurred.

Lifestyle changes including seeing a dietitian, and exercise either by joining a gym or in an organised exercise program.

Treatment for Miss B’s hirsutism include cosmetic measures, as well as hormonal, as it will take at least 6 months for hormone treatment to be effective.

• Cosmetic measures: shaving, depilatory creams, electrolysis

• Hormonal treatment: oral contraceptive pill with an antiandrogen (Yasmin or Diane 35) ± antiandrogen such as aldactone

The oral contraceptive pill will have the added benefit of regulating the menstrual period.

In the future, if she wishes to conceive, Miss B may require ovulation induction therapy such as clomiphene citrate, gonadotrophins or laparoscopic ovarian drilling (‘golf-balling’), but she is not ready to start a family at present.

20 marks total

Discussion

The expectation is that the candidate will take an adequate history such that PCOS is suspected and that the investigations are appropriate for diagnosing the problem and excluding other causes for the history. With the history it will be apparent that the patient is concerned about hirsutism and appropriate treatment will be discussed. In addition to treatment for the medical problems, as this patient is significantly overweight, lifestyle measures need to be discussed. Marks will not be awarded for investigations that are not appropriate.

E8

Q1

History

• 32-year-old primigravida at 8/40 gestation by early ultrasound

• Dizygotic twins by early ultrasound

• Planned pregnancy by IVF. Required 6 cycles to achieve pregnancy. Had a double embryo transfer for her last cycle of treatment (previously having single embryo transfers)

• Reason for IVF: male factor infertility (low sperm count)

• Mild hyperemesis gravidarum and breast tenderness

• Was on folate at time of pregnancy, and rubella immune (checked by IVF specialist)

• Has not had any antenatal testing yet

• Regular cycle 28 days, periods not heavy or painful; no intermenstrual or post-coital bleeding

• No history of STDs/PID. Last Pap smear 1 year ago (normal, always normal)

• No medical history of note

• No past surgical history

• No family history of note

• Married (good relationship). Non-smoker, non-drinker, no recreational drugs. Works as a marketing manager for a superannuation company.

Intrapartum

• Increased need for operative delivery (forceps, breech extraction of second twin, caesarean section), with increased risk of trauma to mother and baby

Q3

Had CVS of both twins without complication. Currently 14/40 gestation

Options

1. Termination of both twins by either suction curette/dilatation and evacuation of uterus, or by medical termination with misoprostol vaginally. Will need anti-D.

2. Selective feticide of affected twin by intracardiac injection of potassium chloride, as a dizygotic pregnancy, without a shared circulation. Safe for non-affected twin (<5% unintended loss of non-affected twin), but still increased risk of premature delivery of the remaining twin.

Can plan to deliver the remaining twin vaginally as long as cephalic presentation, and no other contra-indications to vaginal delivery.

3. Expectant management, if does not wish to undergo termination of pregnancy of either twin. Second twin has increased risk of FDIU, especially if co-existent congenital abnormalities, but FDIU of affected twin will not cause increased risk of cerebral palsy/FDIU of unaffected twin as long as no shared circulation (as appears to be the case in this patient).

20 marks total

Discussion

The incidence of twins and triplets has increased in Australia and New Zealand with the use of assisted reproductive technologies such as IVF. The difficulty of maternal serum screening for Down syndrome in these patients is that the result is not fetus specific, and that a raised result in one twin may be masked by a normal result in the other. Therefore, the best screening test available, which is fetus specific and non-invasive, is the measurement of nuchal translucency by ultrasound in the first trimester. The addition of first trimester maternal serum screening may increase the sensitivity of nuchal translucency measurement.

The candidate in this OSCE is expected to counsel the patient about the management of a twin pregnancy, and to demonstrate an understanding of Down syndrome screening in a twin pregnancy. The second part of the OSCE tests the candidate’s ability to counsel and manage a patient, first with a high-risk screening result and then with an anomalous Down syndrome dichorionic twin pregnancy.

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Tags: Practice OSCEs in Obstetrics & Gynaecology

Jun 15, 2016 | Posted by admin in GYNECOLOGY | Comments Off

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