1. Prof. Sadqa Aftab Consultant anesthetist cardiac surgery dept CHK
Thyroid storm/crisis
Prof. Sadqa Aftab
Consultant anesthetist cardiac surgery dept CHK

2. A 18 yr old women 78 Kg was diagnosed as Graves disease and treated with propylthiouracil 250mg and propranolol 40mg twice daily. After one year she was planned for elective thyroidectomy, she had also history of asthma with occasional use of Inhaled Albuterol. On examination Thyroid was slightly enlarged and Her labs were within normal limit

3. On morning of surgery vitals and labs were
BP 134/74 mmHg
HR 100/min
Temp 37 C
Hb 11.4gm/dl
ECG sinus tachycardia
No history of previous anesthesia or surgery
All medication were withheld in morning on advice of surgeon and tachycardia attributed to anxiety before surgery
Premedication's midazolam,

4. Induction
Propofol, fentanyl and Rocuronium
Maintenance
O2/N2O/isoflurane
Thirty mins after incision during dissection around thyroid gland HR increases to 110 to 120/min
Additional bolus of fentanyl was given
Sweating started with temp of 39 but end tidal tidal CO2 was 30mmHg and soda lime absorber does not indicate undue warmth

5. Management
Metopropolol 1mg given while proponolol avoided because of asthma
Cooling measures with cooling and cold IV fluids started & urinary catheter was inserted
Then Temp decrease to 38 C, SPO2 97%, BP /40-50 mmHg, HR 110/min

6. Metopropolol was repeated on interval and total of 10 mg was administered along with repeated doses of fentanyl and Rocuronium during surgery
Subtotal thyroidectomy completed with minimum blood loss
Patient transferred to ICU

7. ICU management
One hr later with vitals BP 145/65 mmHg, HR 108/min, Temp 37 C, R/R 23/ min, SPO2 98%,
ABG PH 7.28, PaO2 209 mmHg ,
PCO2 48 mmHg, HCO3 22, BD -5 with 40% Fio2 on spontaneous mode
Reversal done with neostigmine and glycopyrolate
Patient was responsive to verbal command and extubated after T piece trail
Propylthiouracil was started HR came down to 100/min, patient was discharge to ward on next day

8. Discussion
Thyroid storm/crisis in surgical patients
Surgery
Infection
Trauma
Overdose of thyroid replacement medication
Usually occur 6-18 hrs postoperatively in unprepared or inadequately prepared patients
But can happen intraoperatively mimicking malignant hyperthermia

9. Clinical presentation fever, tachycardia, profuse sweating, systolic hypertension and widened pulse pressure, atrial fibrillation. Restlessness and agitation, CCF
Differential diagnosis include anaphylactic reaction, malignant hyperthermia, pheochromocytoma, neuroleptic malignant syndrome (Unlike MH, not associated with muscle rigidity, elevated CPK, or marked degree or lactic or respiratory acidosis)

11. Treatment if crisis occurs
ABC’s
General supportive measures cooling, cold IV fluid, treatment of hypovolemia
IV propanolol (.5mg increments)/esmolol to control heart rate until less than 100. (Diminish metabolic effect of thyroid hormones Proponolol drug of choice)
Propylthiouracil 250mg Q6 hours orally or by NG tube Reducing secretion and production of thyroid hormone
Sodium Iodide 1 gram over 12 hours

12. 6. Treat underlying illness e
6. Treat underlying illness e.g correction of any precipitating events (infection)
7. Cortisol is recommended if there is any coexisting adrenal gland suppression
8. Treatment of possible thyroid crisis should not await the arrival of confirmatory thyroid function test
9. Mortality rate is approximately 20%

13. In Our case
Preoperatively
Possibly patient was undertreated because of absence of obvious sign and symptoms
Antithyroid medications and beta-blockers should be continued through the morning of surgery.
On day of surgery BP 134/74 mmHg, HR 100/min, Temp 37 C, Hb 11.4gm/dl
Monitor shows ECG sinus tachycardia

14. Crisis precipitated
With stress of anesthesia and surgery
To Differentiate from malignant hyperthermia (normal End tidal CO2, absence of arrhythmias, skin flushing, ABG with normal PaCO2, and absence of Hypoxemia
Crisis managed
Early intervention with B blocker prevented disaster

15. Lesson to learn
Thyroid storm is uncommon but occur in unprepared and inadequately treated patients
Be careful especially in day case surgery for hyperthyroid patient undergoing non thyroid surgery
Brief period to assess and formulate plan of anesthesia does not serve the patient well
Anesthetist should meticulously assess euthyroid state of patient