Hyperthyroidism and Blunt Multi-System Trauma

Abstract

We report a case of multi-system trauma after a motor vehicle collision with documented hyperthyroidism. Intensive care was required including a tube thoracostomy and a tracheostomy. Elevated thyroid function tests were noted and the patient responded to anti-thyroid medication. The patient was decannulated prior to discharge to home.

48 year-old male driver was involved in a rollover motor vehicle collision with ejection. He was intubated in the field and transported to a Level 1 trauma center. At the time of admission his blood pressure was 184/132 with a pulse of 118 and a respiratory rate of 24. The initial abdominal ultrasound was negative and the pelvis was stable on exam.

The chest x-ray revealed a moderate right pneumothorax with 1^st and 2^nd rib fractures. A right chest tube was inserted. An admission arterial blood gas revealed a PH of 7.11, PC02 of 63 and a Pa02 of 134 with a bicarbonate of 20 and a base deficit of 9. A CT survey revealed thyromegaly with surrounding blood and a spleen laceration with a blush. Intensive care unit observation ensued and no further therapy for the spleen injury was required. The patient remained hypertensive and tachycardic. Thyroid function tests were obtained. Free T4 and T3 were both elevated and TSH was very low. He appeared toxic and a presumptive diagnosis of thyrotoxicosis was made with impending thyroid storm.

Methimazole was initiated along with beta-blockade (propranolol). The thyroid function tests remained elevated and he was switched to Propylthiouracil. His vital signs stabilized and he was eventually extubated. Post-extubation stridor developed and a tracheostomy was performed. He was weaned and eventually decannulated. He was discharged to home in satisfactory condition on daily anti-thyroid medication.

Discusssion

The clinical presentation of any trauma victim mandates that the Advanced Trauma Life Support principles are followed [1]. The airway is secured, breathing assessed along with circulation and balanced resuscitation is initiated. All acute life-threatening injuries are detected during the primary survey and a complete head to toe evaluation is performed during the secondary survey. For the patient described above, the airway was secured in the field with an endotracheal tube. A right pneumothorax was detected on the primary survey and treated with a chest tube. Profound acidosis (respiratory and metabolic) was evident and hypertension and tachycardia were noted on admission. Trauma patients may be hypertensive because of pain and pre-existing essential hypertension that has been poorly controlled. If they are hypotensive on admission it is most often related to blood loss or profound tissue injury. In the patient described above the spleen injury was a potential site of hemorrhage but proved to be clinically inconsequential with close monitoring. No transfusions were required during the monitoring phase. Hyperthyroidism was suspected based on the persistent tachycardia and the thyroid enlargement noted on initial imaging. Thyroid function tests confirmed the over activity and appropriate treatment was implemented. Graves disease is the most common cause of hyperthyroidism overall. Toxic multinodular goiter and toxic adenoma are additional causes. Amiodarone has been recognized as a cause of hyperthyroidism in populations that are iodine deficient. Graves disease usually presents at a young age (between 20 and 40 years) in a typical pattern including heat intolerance, agitation, palpitations, tachycardia, hypertension and often altered mentation [2]. Exophthalmos may be present. Increased thyroid hormone production is the hallmark. Thyroid stimulating hormone is suppressed. Free T4 is elevated and Free T3 may be increased as well. Thyrotropin receptor antibodies (Trab) act as a TSH receptor agonist. Trab can be used to monitor progress and possibly predict prognosis regarding remission. The principles of clinical management include; decreasing thyroid hormone production and blocking the adrenergic effects of thyroid hormone excess. Methimazole is a mainstay in this regard along with propylthiouracil. Methimazole inhibits the conjugation

of monotiodtyrosine with di-iodotyrosine to form thyroxine. This shuts down synthesis. When combined with beta blockade, usually in the form of propranolol, clinical improvement is often seen. Propylthiouracil offers the advantage of inhibiting the conversion ofT4 to T3 peripherally [3].

The patient described was started on methimazole but rapid clinical improvement did not occur and the thyroid function tests did not decrease. Once he was switched to propylthiouracil, clinical improvement ensued. Proopylthiouracil may be preferred in the management of patients with thyroid storm because of the peripheral effects.

Thyroid storm can be defined with the Burch-Wartofsky point scale [4]. The seven domains of this scale define the clinical presentation. These domains include thermoregulatory dysfunction, cardiovascular manifestations – tachycardia, the presence of atrial fibrillation, the presence of congestive heart failure, GI-hepatic dysfunction, central nervous system disturbance and precipitating history. If the total score is above 45 points – thyroid storm is present.

25-44 points reflects impending storm and less than 2S points means storm is unlikely (Table 1). Precipitating history may include abrupt cessation of anti-thyroid drug therapy, thyroidectomy or non-thyroidal surgery in a patient with undiagnosed hyperthyroidism. For the patient described, trauma may have been a precipitating cause. His clinical manifestations included; marked tachycardia, hypertension and altered mental state. Impending storm was likely. One can only speculate if the hyperthyroidism in this case contributed to the motor vehicle collision.

  

    
Pirameters
    
Scoring sirstem
  
  

    
Thermoregulatory dysfunction
  
  

    
Oral Temperature (F)
  
  

    
99-99.9 
    
5
  
  

    
100-100.9 
    
10 
  
  

    
101-101.9 
    
1S 
  
  

    
102-102.9 
    
20 
  
  

    
103-103.9 
    
25 
  
  

    
104 
    
30 
  
  

    
Cardiovascular dysfunction
  
  

    
Tachycardia 
  
  

    
90-109 
    
5 
  
  

    
110-119 
    
10 
  
  

    
120-129 
    
15 
  
  

    
130-139 
    
20 
  
  

    
>140 
    
25 
  
  

    
Congestive heart failure
  
  

    
Absent 
    
0
  
  

    
Mild (pedal edema)
    
5
  
  

    
Moderate (bibasal rales)
    
10 
  
  

    
Severe (pulmonary oedema)
    
15 
  
  

    
Atrial fibrillation
    

  
  

    
Absent 
    
0
  
  

    
Present 
    
10 
  
  

    
Central nervous system symptoms
  
  

    
Absent 
    
0
  
  

    
Mild agitation
    
10
  
  

    
Moderate (Delirium, psychosis, extreme lethargy)
    
20
  
  

    
Severe (Seizure, coma)
    
30 
  
  

    
Gastrointestinal /hepatic dysfunction
  
  

    
Absent 
    
0
  
  

    
Moderate (Diarrhea, nausea, vomiting, abdominal pain)
    
10 
  
  

    
Severe (Unexplained jaundice)
    
20 
  
  

    
Precipitating event
  
  

    
Absent 
    
0
  
  

    
Present 
    
10 
  
  

    
Burch    HB, Wartosfsky L. Endocrinol Metab Clinics North America. 1993; 22: 263-277. 
  

Table 1: Burch and Wartofsky's scoring system.