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

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

4. 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 ? * pain; nausea/vomiting; untreated HTN …  What is it about MMH that leads to the higher risk of bleeding? Post-Thyroidectomy Haemorrhage

5. HQSC Cohort Analysis Jan 2002 - Apr 2012 n = 621 Mean Age (SD) 48.3(+14.5) Median BMI (IQR) 29.2(9.8) ASA 1/2 50982% Smoker 20132.4% Pre-existing HTN 18632.3% Female gender 52585% European 18229% Maori 17528% Pacific Is 11518.5% Post-Thyroidectomy Haemorrhage

6. Observations on Thyroid Surgery Total Thyroidectomy 36058% Mean (SD) Thyroid weight (gm) 91.9(+96.5) Median (range) Thyroid weight (gm) 52.7(4-520) Benign disease 48778% Surgery @ MSC 41367% Number w post-op Systolic BP >150 mmHg 26547% Median (range) High Systolic BP post-op 15098 - 230 post-operative bleeds: 15/621 (2.4%) HQSC Cohort Analysis Jan 2002 - Apr 2012 Post-Thyroidectomy Haemorrhage

7. 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 Univariate Analysis CMDHB data European (182) Pacific (115) Maori (175) Asian (149) 2.2% 1.7% 6.1% 0% Post-Thyroidectomy Haemorrhage

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

9. Regression Analysis Thyroid Size (weight) p = 0.0072 [OR 1.05 (per 10 gms)] 95% CI = 1.01 - 1.09 Highest post-op Systolic BP p = 0.016, [OR: 1.39 (per 10 mmHg)] 95% CI=1.09-1.76 Statistical Issues Surgical Team: there is some statistical effect of surgical team - inclusion improves the fit for the statistical model 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 Post-Thyroidectomy Haemorrhage

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

13. 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 Post-Thyroidectomy Haemorrhage

14. 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 CampusBMI Systolic BP Ethnicity Surgical TeamGland Weight Post-Thyroidectomy Haemorrhage

16. n = 30,142 Br J Surg 2012; 99: 373 – 379 519 (1.7%) Rate range: 0.4 - 2.8%

17. Br J Surg 2012; 99: 373 – 379 Rate range: 0.4 - 2.8% 519 (1.7%) (4/994) (9/318) CMDHB

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

19. 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…” Liston R “ Lectures on the operations of surgery and on diseases and accidents requiring operations.” Lea and Blanchard, Philadelphia, 1846; pp 318-326. While Intra-operative Mortality risk has “disappeared”, Post-operative Haemorrhage remains life-threatening Post-Thyroidectomy Haemorrhage

20. 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 Statistical Issue Post-Thyroidectomy Haemorrhage

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

22. 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 Arch Surg. 2009;144(12):1167-1174 Post-Thyroidectomy Haemorrhage

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