The diagnosis of intraoperative thyroid storm or thyrotoxic crisis is suggested by tachycardia, hypertension, hyperthermia, and widened pulse pressure. The diagnostic dilemma lies in the fact that these signs are nonspecific and occurring with other intraoperative emergencies such as malignant hyperthermia (MH) and sepsis. Once other possibilities are eliminated, intraoperative management is aimed at curbing the hemodynamic responses via use of IV thionamides, iodide, β-blockers, and occasionally steroids and vasoactive medication to treat recalcitrant hemodynamic instability. One must confirm diagnosis by laboratory evaluation of triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone levels.
Written consent for publication of this case report was obtained from the patient’s mother.
A 15-year-old cognitively normal male with mild spastic cerebral palsy presented after sustaining a 15-foot fall from a tree house. He had landed on his right shoulder and did not experience any loss of consciousness. After the fall, he walked back into his house and his parents brought him to the emergency room for evaluation. Imaging revealed cervical spine fractures, and the patient was placed in a c-collar and transferred to the pediatric intensive care unit. Subsequent imaging revealed a posteriorly displaced dens fracture, a C1 anterior arch fracture, ligamentous injury, and mild spinal cord contusion. The patient denied weakness, tingling, or numbness of his extremities. He was scheduled for halo traction placement in the operating room (OR) 3 days after his initial presentation after considerable planning and discussion among the orthopedic surgery, neurosurgery, and pediatric intensive care unit teams to determine whether fixation of the fracture versus halo traction placement and observation was a better option for this patient.
His medical and surgical history included several uncomplicated general anesthetics for orthopedic procedures and Botox injections in his lower extremities. He took no medications at home and had no known drug allergies. His vital signs were axillary temperature 37.5°C to 38.0°C, heart rate 120 to 137 bpm, arterial; blood pressure 125 to 144/69 to 102 mm Hg, respiratory rate 17 to 27 breaths per minute, with oxyhemoglobin saturation between 94% and 98% on room air. He was 171.6 cm tall and 47.7 kg (body mass index 16.2). Physical examination revealed a slim adolescent male in a c-collar in no acute distress. Other than sinus tachycardia, no other abnormalities were noted. Besides a mildly increased white blood cell count of 11,300 mcgL, all other laboratory studies were normal.
On the morning of surgery, the anesthesia team reevaluated the patient, this time with his mother present. Physical examination revealed an anxious and tremulous teenager who lay in his bed with his gown pushed down to his waist, explaining that he felt hot. His precordial cardiac impulse was clearly visible. The patient was irritable and difficult to engage in conversation, and his mother was asked about his level of anxiety. She reported having taken her son to see his outpatient physician the day before his injury because of symptoms of nervousness and inability to gain weight. The patient’s mother also noted that she did not want her son to have an additional venipuncture to repeat thyroid function tests before the surgery. The anesthesia team decided that because the surgery was urgent given his multiple cervical fractures and soft tissue injuries, they would proceed with the surgery and aggressively treat the patient for presumed thyrotoxicosis while also sending confirmatory laboratory tests.
In the OR, general anesthesia was induced with sevoflurane, nitrous oxide, and oxygen, followed by ketamine and fentanyl boluses to facilitate intubation. While maintaining in-line neck stabilization, the trachea was intubated using a video laryngoscope (Glidescope, Verathon, Inc., Bothell, WA). During induction and especially after intubation, the patient’s systolic blood pressure increased to 150 mm Hg and his heart rate increased from 120 to 150 to 160 bpm. Additional venous access was secured, a radial arterial catheter was inserted, and blood for thyroid function tests sent to the laboratory. Infusions of dexmedetomidine and remifentanil were begun and the patient’s arterial blood pressure decreased to 100/50 mm Hg and his heart rate decreased to 100 to 110 bpm over the next several hours. His temperature remained 37.5°C to 37.7°C. The intraoperative laboratory work revealed an undetectable thyroid-stimulating hormone level, T3 508 ng/dL (nl 60–228 ng/dL) and T4 30.5 mcg/dL (nl 4.9–10.5 mcg/dL). At the conclusion of surgery, sevoflurane and dexmedetomidine were both discontinued and the remifentanil infusion decreased. An esmolol infusion was also started before emergence because the patient’s arterial blood pressure increased with systolic blood pressure higher than 160 mm Hg and his heart rate returning to 120 to 140 bpm. The trachea was extubated while maintaining remifentanil (0.1 mcg/kg/min) and esmolol (50–150 mcg/kg/min) infusions before leaving the OR.
Postoperatively, the esmolol infusion was transitioned to propranolol, methimazole, and saturated solution of potassium iodide per nasogastric tube. His vital signs became normal as his symptoms improved, and he was discharged home on postoperative day 6 receiving oral methimazole and propranolol with plans for an endocrinology follow-up as an outpatient.
Our experience highlights some important aspects of the perioperative management of thyroid crisis. The incidence of thyroid storm in the pediatric population has been reported as 0.1 to 3/100,000 hospitalized patients.1,2 In retrospect, further questioning of the patient and his mother revealed additional signs and symptoms suggesting the presence of hyperthyroidism many months before his presentation. The patient’s mother had noticed that her son was suffering from increased fatigue and anxiety, worsening performance in school, increased appetite and food intake without weight gain, heat intolerance, headaches, and poor sleep habits over several months. She also volunteered a personal history of Graves disease that was in remission.
Although the patient had been in the hospital for 3 days and this was not a true surgical emergency or urgency, it was decided that this case needed to proceed to minimize the risk of the patient having a worse outcome if not corrected sooner. However, it is tempting to speculate that had the relevant questions been asked preoperatively, the anesthetic may have been modified to mitigate the crisis, for example, with β-adrenergic blockade and thionamides initiated on the day before surgery. This raises the question of whether our usual preoperative evaluation is likely to focus on such questions. By the time the mother revealed the above history, the diagnosis was already strongly suspected, and questioning was directed at this diagnosis. Absent this knowledge gained in hindsight, any further information uncovered preoperatively may have been assumed to be nonspecific.
The most common signs and symptoms in children presenting with thyroid storm are fever, diaphoresis, widened pulse pressure, diarrhea, hypertension, and tachycardia.3,4 In an anesthetized patient, however, thyroid storm would be more difficult to diagnose, especially since tachycardia, hypertension, and fever may also suggest MH, pheochromocytoma, neuroleptic malignant syndrome, sepsis, ectopic atrial tachycardia, inadequate anesthesia, and anaphylactic reactions. MH can often be excluded by the absence of increasing end-tidal carbon dioxide, muscle rigidity, acidosis, and masseter spasm. Thyroid storm has been shown to be precipitated by such events as surgery, pregnancy, trauma, infection, seizures, and emotional stress.5–9
Treatment of these patients is centered on treating the hyperthyroid state, maintaining hemodynamic stability, and addressing the inciting event if possible. Intravenous thionamides (propylthiouracil and methimazole) continue to be the mainstays of therapy for controlling increased thyroid hormone levels. Other treatments are centered on acutely decreasing temperature, controlling hemodynamic responses with β-blockers and opioids, and corticosteroid supplementation as necessary for possible adrenal insufficiency, as well as inhibiting peripheral conversion of T4 to T3.10 The decision to stop or postpone a surgical procedure will ultimately depend on the child’s hemodynamics as well as the comfort level of the anesthesiologist and surgeon to proceed and the emergency/urgency of the procedure. The risks of proceeding with the surgery included worsening of the thyrotoxicosis, further provoking an episode of thyroid storm or even coma and/or death. Had the thyroid function tests been available before the operative case, we admit that an endocrine consult would have been requested and the increased hormone levels would have been acutely treated, either with IV thionamides or β-blockers. Intraoperative management would have been unchanged, however, because the patient would have remained at increased risk for development of thyroid storm until many weeks after therapy had begun, and the patient’s unstable cervical fracture required more immediate attention. Delay of at least 1 to 2 days would have been helpful and likely would have reduced his anesthetic risk considerably.
Whether this patient actually had thyroid storm versus thyrotoxicosis is also debatable. Thyrotoxicosis is defined as an elevation of circulating thyroid hormone levels, regardless of the cause, hyperthyroidism being a cause secondary to increased thyroid function. Thyroid storm is an extreme manifestation of thyrotoxicosis, usually precipitated by some event or underlying condition. The scoring system by Burch and Wartofsky4 could have indicated an event highly suggestive of thyroid storm if in this patient points were added for mild preoperative agitation. Otherwise, his score would only suggest impending thyroid storm. More recent diagnostic criteria developed by Akamizu et al.3 would also depend on identifying his symptoms of restlessness, agitation, or lethargy, along with tachycardia and thyrotoxicosis diagnosed by laboratory values drawn at the time of diagnosis. Postoperatively, the endocrinology consultants were unconvinced that this was a case of thyroid storm. They labeled his presentation as thyrotoxicosis and severe hyperthyroidism. Regardless of the semantics of classifying various levels of severe thyroid hyperfunction, the child was fortunate that no further or permanent harm occurred. That the diagnosis was made expeditiously and that treatment begun quickly can only serve as a reminder of the dangers of thyrotoxicosis and the urgent need for prompt diagnosis.
The diagnosis of intraoperative thyroid storm or thyrotoxicosis should be considered in the presence of tachycardia and hypertension even in children and adolescents while excluding alternative diagnoses including MH. Initial treatment is usually directed at controlling hyperthermia, hypertension, and tachycardia. Depending on the severity of the presentation and the response to initial measures, antithyroid medications are then initiated even before the laboratory results are available. This case illustrates the extremely rare circumstance of intraoperative hyperthyroidism in a pediatric patient that was successfully managed and resulted in no permanent sequelae.
1. Birrell G, Cheetham T. Juvenile thyrotoxicosis; can we do better? Arch Dis Child. 2004;89:745–50
2. Franklyn J. Thyrotoxicosis. Clin Med. 2003;3:11–5
3. Akamizu T, Satoh T, Isozaki O, Suzuki A, Wakino S, Iburi T, Tsuboi K, Monden T, Kouki T, Otani H, Teramukai S, Uehara R, Nakamura Y, Nagai M, Mori MJapan Thyroid Association. . Diagnostic criteria, clinical features, and incidence of thyroid storm based on nationwide surveys. Thyroid. 2012;22:661–79
4. Burch HB, Wartofsky L. Life-threatening thyrotoxicosis. Thyroid storm. Endocrinol Metab Clin North Am. 1993;22:263–77
5. Morrison MP, Schroeder A. Intraoperative identification and management of thyroid storm in children. Otolaryngol Head Neck Surg. 2007;136:132–3
6. Lawless ST, Reeves G, Bowen JR. The development of thyroid storm in a child with McCune-Albright syndrome after orthopedic surgery. Am J Dis Child. 1992;146:1099–102
7. Grimes CM, Muniz H, Montgomery WH, Goh YS. Intraoperative thyroid storm: a case report. AANA J. 2004;72:53–5
8. Aslan IR, Baca EA, Charlton RW, Rosenthal SM. Respiratory syncytial virus infection as a precipitant of thyroid storm in a previously undiagnosed case of Graves’ disease in a prepubertal girl. Int J Pediatr Endocrinol. 2011;2011:138903
9. Lee HS, Hwang JS. Seizure and encephalopathy associated with thyroid storm in children. J Child Neurol. 2011;26:526–8
10. Landgraf L, Grubina R, Chinsky J. Altered mental status in a 16-year-old girl: the calm before the storm. Clin Pediatr (Phila). 2008;47:720–4