Life-Threatening Haemorrhage Following Thyroid Surgery

1. Life-Threatening Haemorrhage Following Thyroid Surgery Randall Morton, Terina Pollock Counties-Manukau District Health Board Auckland University • CMDHB General & Thyroid Surgeons • Alain Vandal, Statistician Acknowledgements:

2. Post-Thyroidectomy Haemorrhage 870/ 65,962 (1.3%) Promberger et al Br J Surg (2012) 519/30,142 (1.7%) “no definite perioperative risk factor has been identified to predict occurrence of cervical haematoma” CMDHB audit 2000-2002 4/94 (4.25%) 274/ 32,160 (0.8%) Bononi M, et al. “Incidence and circumstances of cervical hematoma complicating thyroidectomy …” Head Neck 2010; 32:1173-1177

3. Post-Thyroidectomy Haemorrhage CMDHB Thyroid Surgery 2002-08 7/406 (1.7%) 7 cases of RTT matched from contemporaneous controls for: Gender; Ethnicity; Operation; Pathology; Campus; Age • Logistic regression: • post-op systolic BP >150 mmHg • (p = 0.005) MSC 1/241 (0.4%) MMH 6/165 (3.6%)

4. Post-Thyroidectomy Haemorrhage • Questions: • What is the profile for systolic BP after thyroid surgery ? • How many thyroidectomies have high BP and not bleed ? • What factors* are associated with/ lead to high systolic BP ? • Is there a “safe” level of post-thyroidectomy systolic BP ? • What is it about MMH that leads to the higher risk of bleeding? * pain; nausea/vomiting; untreated HTN …

5. Post-Thyroidectomy Haemorrhage HQSC Cohort Analysis Jan 2002 - Apr 2012 n = 621

6. Post-Thyroidectomy Haemorrhage HQSC Cohort Analysis Jan 2002 - Apr 2012 Observations on Thyroid Surgery post-operative bleeds: 15/621 (2.4%)

7. Post-Thyroidectomy Haemorrhage Univariate Analysis CMDHB data ASA status n.s. Wound Drain n.s. Surgical Time n.s. Surgical team 0.13 Ethnicity 0.024 BMI 0.022 Location of Surgery 0.013 Highest post-op BP 0.007 Gland Weight 0.001

8. Post-Thyroidectomy Haemorrhage Regression Analysis Highest post-op Systolic BP p = 0.016, [OR: 1.39 (per 10 mmHg)] 95% CI=1.09-1.76 Thyroid Size (weight) p = 0.0072 [OR 1.05 (per 10 gms)] 95% CI = 1.01 - 1.09

9. Post-Thyroidectomy Haemorrhage Regression Analysis Highest post-op Systolic BP p = 0.016, [OR: 1.39 (per 10 mmHg)] 95% CI=1.09-1.76 Thyroid Size (weight) p = 0.0072 [OR 1.05 (per 10 gms)] 95% CI = 1.01 - 1.09 Statistical Issues • Thyroid Weight: non-normal distribution skewed to larger thyroids • weight loses significance when data log-transformed • [OR: 1.44 (each doubling of weight) CI = 0.91-2.29] Campus (MMH/MSC): confounding between campus and surgical team Surgical Team: there is some statistical effect of surgical team - inclusion improves the fit for the statistical model

10. Post-Thyroidectomy Haemorrhage Highest Systolic BP Thyroid Weight [log-scale]

11. Post-Thyroidectomy Haemorrhage

12. Post-Thyroidectomy Haemorrhage

13. Post-Thyroidectomy Haemorrhage SUMMARY • Post-thyroidectomy haematoma is a life-threatening risk, but the risk should be ~ 1% or less • Post-Anaesthetic Systolic Blood pressure is associated with bleeding in CMDHB (but not necessarily causative) • CMDHB is making some progress (esp in MSC) in reducing our risk • Controlling systolic blood pressure may help reduce the risk of post-op haemorrhage

14. Post-Thyroidectomy Haemorrhage IMPLICATIONS FOR CMDHB • Introduce SPC* methodology for Thyroid Surgery • Agree BP management from time of booking surgery • Agreement for post-op management protocols • Methodology to capture process information • Monitor at least 2 years … Include other DHBs ? *Statistical Process Control Sources of variation Campus BMI Systolic BP Ethnicity Surgical Team Gland Weight

15. Post-Thyroidectomy Haemorrhage

16. n = 30,142 Br J Surg2012;99: 373 – 379 Rate range: 0.4 - 2.8% 519 (1.7%)

17. CMDHB Br J Surg2012;99: 373 – 379 (4/994) 519 (1.7%) Rate range: 0.4 - 2.8% (9/318)

18. Post-Thyroidectomy Haemorrhage Highest Systolic BP 2 cases - bled before PACU (no pre-bleed systolic BP recorded) 2 cases - late bleeds (drains*2) Thyroid Weight [log-scale]

19. Post-Thyroidectomy Haemorrhage Robert Liston (1794-1847) “… You could not cut the thyroid gland out of a living body in its sound condition without risking the death of the patient from hemorrhage…” While Intra-operative Mortality risk has “disappeared”, Post-operative Haemorrhage remains life-threatening Liston R“Lectures on the operations of surgery and on diseases and accidents requiring operations.”Lea and Blanchard, Philadelphia, 1846; pp 318-326.

20. Post-Thyroidectomy Haemorrhage Statistical Issue • Thyroid Weight: non-normal distribution skewed to larger thyroids • weight loses significance when data log-transformed • OR: 1.44 (each doubling of weight) CI = 0.91-2.29

21. Post-Thyroidectomy Haemorrhage What factors can we influence to try to avoid post-operative Haematoma formation? • Hospital/Surgeon Volume • Vessel Management (Surgeon) • Trendelenburg/ Valsalva (Surgeon) • Surgical Drains (Surgeon) • Nausea/ Vomiting control (Anaesthetist) • NSAIDs/ pain relief (Anaesthetist) • Other (Patient/Disease); - BMI/ Gland size/ Medication/ etc

22. Post-Thyroidectomy Haemorrhage Arch Surg. 2009;144(12):1167-1174 • Technology has allowed: • Better control of bleeding during thyroid surgery • General reduction in surgical blood loss While Intra-operative Mortality risk has “disappeared”, Post-operative Haemorrhage remains life-threatening

23. Post-Thyroidectomy Haemorrhage 870/ 65,962 (1.3%) Promberger et al Br J Surg (2012) 519/30,142 (1.7%) “no definite perioperative risk factor has been identified to predict occurrence of cervical haematoma” CMDHB audit 2000-2002 4/94 (4.25%) 274/ 32,160 (0.8%) Bergenfelz et al. Lang Arch Surg (2008): 77/3660 (2.1%) Bononi M, et al. “Incidence and circumstances of cervical hematoma complicating thyroidectomy …” Head Neck 2010; 32:1173-1177