Case Presentation

1. Case Presentation Matt Dickson Respiratory ST3

2. Can you review a patient on the labour ward?

3. Presentation to A&E • 37 year old female • 31/40 pregnant • Gravida 1 Para 0 • 2 week history of palpitations and gradually worsening breathlessness on exertion • Sent to NSECH by community midwife on 2.12.15

4. Patient background • Normal pregnancy • Never smoked • No illicit drug/alcohol use • Severe anxiety and depression • Suicide attempt in early pregnancy • Sertraline 150mg OD • Chlorpromazine 75mg ON • Lives with partner

5. Initial assessment • Appeared well • Denied chest pain, cough, fever, ankle swelling • HR 140bpm, normotensive, no respiratory compromise • Heart sounds normal • Chest clear • Abdomen soft; gravid uterus • No calf swelling

6. Investigations • Bloods: • Hb 115, WCC 16.6, CRP 7, electrolytes normal • Urine dip +ve for nitrites • ECG sinus tachycardia, normal axis • Ultrasound doppler lower limbs negative for DVT • CXR normal • Went on to have CTPA

7. Initial management • Treated for UTI • Telemetry • Given treatment dose tinzaparin to cover for PE • Referred to on call medical registrar

8. PE in Pregnancy

9. Pulmonary Embolism in Pregnancy • Risk of PE in antenatal period is 4-5 times greater than non-pregnant women of same age1 • 1 in 1000 pregnancies • Percentage of those investigated for PE who have PE is 2-6%2-4 • Puerperium most likely period for PE • Typical symptoms of PE, however lower abdominal pain also symptom reflecting extension of clot to pelvic vessels • If DVT remains untreated, 15-24% will develop PE • PE in pregnancy fatal in 15%; 66% of these die within first 30 minutes5,6

10. Investigating DVT in Pregnancy • If suspicion strong, treat with LMWH while investigations ongoing • Compression duplex ultrasound for suspected DVT • If test negative, but clinical suspicion high: • Not for anticoagulation • Repeat duplex ultrasound on day 3 and 7 • Strategy evaluated in prospective cohort study of 221 pregnant women with suspected DVT7 • Sensitivity of serial duplex scans was 94.1% (95% CI 69.2-99.7%) • Negative predictive value 99.5% (95% CI 96.9-100%) • Consider MR venography if duplex US negative and iliac vein thrombosis suspected

11. Investigating PE in Pregnancy • ECG: • Greater diagnostic value in pregnancy, abnormal in 41%8 • T wave inversion (21%) • S1Q3T3 pattern (15%) • RBBB (18%) • ABG: • Limited diagnostic value, low incidence of hypoxia • 10% have pO2 level below 8kPa • 3% have O2 sats below 90% • D-dimer: • Should not be performed in pregnancy

12. Investigating PE in Pregnancy (2) • Chest X-ray • Exclude other pulmonary disease • Normal in over 50% with proven PE8 • Radiation dose to foetus is negligible • Lower limb compression duplex ultrasound • If positive for DVT, no need to investigated further • If negative, for further investigation • Ventilation-Perfusion Scan if Chest X-ray normal • CTPA if Chest X-ray abnormal

13. Chest Imaging in Pregnancy Chest X-ray: • Radioactive exposure negligible to foetus (<0.01mSv) • Exposure to mother is 0.1mSv • Equivalent to 1-2 weeks of background radiation (average annual worldwide radiation exposure is 2.4mSv)

14. Chest Imaging in Pregnancy Ventilation – Perfusion Scan • Nuclear Medicine Scan measuring airflow and blood flow • Performed in two parts: • Radioactive gas (Xenon/Technetium) inhaled • Tc99m-MAA injected intravenously Interpretation • Normal: no perfusion deficit – PE excluded • Low probability (<20%): perfusion deficit with matched ventilation deficit • Intermediate probability (20-80%): perfusion deficit corresponding to parenchymal abnormality on CXR • High probability (>80%): Segmental perfusion deficits with normal ventilation

15. Chest Imaging in Pregnancy • CTPA: • More readily available • Can identify other pathology • Contrast injection can cause unwanted reactions to mother • Crosses placenta, but not known to be harmful

16. Comparisons of VQ/CTPA9 • VQ: • Ventilation component can often be omitted • Comparative negative predictive values • Similar/marginally higher radiation dose to foetus • Lower radiation dose to mother (0.28mSv to breast tissue) • CTPA: • More readily available • Identify other pathology • Low radiationdose to foetus (1-2mSv) • Higher radiation dose to breast tissue (10-70mSv)

17. Counselling and consenting • No significant risk of teratogenicity, foetal death or growth restriction with both techniques • Slightly increased risk of fatal childhood cancers up to age of 15 (0.003%) in both • Increased risk of breast cancer with CTPA: • Radiation dose varies dependent on breast size, and age of woman • Greater risk of cancer in younger women • Background risk of 25 year old developing Breast Ca over next 10 years is 0.1% (1 in 1000) • CTPA increases risk by 14% • Equates to an additional risk of 0.014%, total risk of 0.114% (11 in 10,000)10

18. Back to our patient… Over 2 days: • CTPA negative! Not a PE • Telemetry: sinus tachycardia, average of 130bpm • Echocardiogram: Small pericardial effusion, normal valves and function • Foetal USS: Normal • Bloods normal including TSH, slightly raised WCC • Urine metanephrines sent • Reviewed by medical registrar, commenced on colchicine for possible pericarditis

19. Next day • No change, feels well • Reviewed again by medical registrar • Colchicine stopped, no convincing evidence of pericarditis (also teratogenic) • Urine metanephrines pending • Discharged with advice

20. Differential diagnoses • Multifactorial sinus tachycardia: • Physiological response of pregnancy • Anxiety • Sertraline use • Pregnancy related pericardial effusion • Possible (but incredibly unlikely!) phaeochromocytoma

21. Pregnancy related tachycardia • Palpitations common in pregnancy • Resting heart rate increases by 25% • Ectopic beats/non-sustained arrhythmias present in 50% of those investigated for palpitations11 • Sustained tachycardias less common (2-3/1000)

22. Causes of tachycardia in pregnancy • Structural heart disease (congenital or acquired) • Accessory pathways/conduction defects • Metabolic • Drugs • Infection, PE, haemorrhage, inflammation • As pregnancy progresses, even minor arrhythmias can present with associated symptoms

23. Following discharge… • Urine and plasma metanephrines elevated!! • But is this significant?....

24. Breakdown of results • Metanephrine normal (metabolite of adrenaline) • Normetanephrine increased (metabolite of noradrenaline • Taking SSRI (also inhibits noradrenaline reuptake) • Hence, normetanephrine levels can be raised with SSRIs

25. Phaeochromocytoma in Pregnancy • Catecholamine secreting tumours • 2-8 per 1,000,000 per year • Episodic headache, sweating and tachycardia • Can cause paradoxical supine hypertension • Difficult to distinguish from pre-eclampsia • Mortality rate in pregnancy is high (hypertensive crises, malignant arrhythmias, multiorgan failure) • Alpha and beta blockade • Aim to deliver via Caesarean section

26. Over the coming weeks…. • Urine and plasma normetanephrines high • Sample repeated several times • MR adrenals – normal • Normal vaginal delivery, no complications • Heart rate decreased post partum • Chromogranin A pending • Discussed with psychiatrist re: stopping SSRI and retesting metaneprines

27. The End

28. References • 1. Heit JA, Kobbervig CE, James AH, Petterson TM, Bailey KR, Melton LJ 3rd. Trends in the incidence of venous thromboembolism during pregnancy or postpartum: a 30-year population-based study. Ann Intern Med 2005;143:697–706 • 2. Hull RD, Raskob GE, Carter CJ. Serial impedance plethysmography in pregnant patients with clinically suspected deep-vein thrombosis. Clinical validity of negative findings. Ann Intern Med 1990;112:663–7 • 3. Chan WS, Ray JG, Murray S, Coady GE, Coates G, Ginsberg JS. Suspected pulmonary embolism in pregnancy: clinical presentation, results of lung scanning, and subsequent maternal and pediatric outcomes. Arch Intern Med 2002;162:1170–5. • 4. Shahir K, Goodman LR, Tali A, Thorsen KM, Hellman RS. Pulmonary embolism in pregnancy: CT pulmonary angiography versus perfusion scanning. AJR Am J Roentgenol 2010;195:W214–20. • 5. Rutherford SE, Phelan JP. Deep venous thrombosis and pulmonary embolism in pregnancy. ObstetGynecolClin North Am 1991;18:345–70. • 6. Gherman RB, Goodwin TM, Leung B, Byrne JD, Hethumumi R, Montoro M. Incidence, clinical characteristics, and timing of objectively diagnosed venous thromboembolism during pregnancy. ObstetGynecol1999;94:730–4 • 7. Chan WS, Spencer FA, Lee AY, Chunilal S, Douketis JD, Rodger M, et al. Safety of withholding anticoagulation in pregnant women with suspected deep vein thrombosis following negative serial compression ultrasound and iliac vein imaging. CMAJ 2013;185:E194–200 • 8. Blanco-Molina A, Rota LL, Di Micco P, Brenner B, TrujilloSantos J, Ruiz-Gamietea A, et al.; RIETE Investigators. Venous thromboembolism during pregnancy, postpartum or during contraceptive use. ThrombHaemost 2010;103:306–11. • 9. Azdaki N, Maleki MH, Kazemi T, Moezi SA, Moghaddam HRM. V/Q scans and computerized tomography pulmonary angiography in pulmonary emboli in pregnancy: Superiority for fetal or mother. Journal of Research in Medical Sciences : The Official Journal of Isfahan University of Medical Sciences. 2014;19(7):683-684. • 10.Cutts BA, Dasgupta D, Hunt BJ. New directions in the diagnosis and treatment of pulmonary embolism in pregnancy. Am J Obstet Gynecol. 2013;208:102–8. • 11. Adamson DL, Nelson‐Piercy C. Managing palpitations and arrhythmias during pregnancy. Heart. 2007;93(12):1630-1636. doi:10.1136/hrt.2006.098822