Nursing Interventions for Potential
Complications After Thyroidectomy

Ann McKennis, RN, CNOR, CORLN
Carolyn Waddington, BSN, RN, CORLN
1995 SOHN 2nd Place Literary Award Winner

INTRODUCTION

While complications following surgical removal of the thyroid gland are rare, their consequences can often be life-threatening. The location of the thyroid gland in relation to the airway and the gland's abundant vascularity are primary reasons the nurse must be alert to early changes seen in the post-operative thyroidectomy patient. An understanding of both the anatomy and physiology of the thyroid gland, as well as the surgical approach itself, can help the nurse to detect potential complications postoperatively. The patient can then receive early intervention to minimize the chance of life-threatening consequences.

HISTORY OF THYROID SURGERY

Surgery on the thyroid gland was first performed around 500 A.D. (Coffey & Petti, 1993). Albucosi was credited with successfully removing goiter in 1000 A.D. (Coffey & Petti, 1993). By the 1880s, Bilroth had performed numerous thyroidectomies, but nearly half of his patients died; the most common cause of death after thyroid surgery was tetany (Coffey & Petti, 1993). This morbidity was secondary to removal of the parathyroid glands, whose function was not well understood at that time.

The greatest contribution to the understanding of thyroid surgery was made by Theodore Kocher, who by 1912 had performed over 5,000 thyroidectomies (Coffey & Petti, 1993). He realized the problems associated with parathyroid gland removal, and advocated subtotal removal of the thyroid gland. Since then, knowledge of the anatomy and function of the thyroid gland has allowed for further refinement of thyroid surgery, resulting in a subsequent decrease in documented postoperative complications.

ANATOMY AND PHYSIOLOGY OF THE THYROID GLAND

Location. The thyroid gland lies in the anterior neck, below the larynx (see Figure 1). It is a highly vascular organ, and consists of two lobes that are connected by an isthmus, which is usually positioned at the level of the upper three tracheal rings. The superior pole of each lobe of the thyroid gland covers the lateral aspects of the thyroid cartilage. The thyroid gland is attached to the trachea by a dense connective tissue inferior to the cricoid cartilage.

FIGURE 1: Illustration of the thyroid and parathyroid glands and their relationship to the larynx and trachea. From Anatomy and Physiology (3rd ed.) (p.558), by G.A. Thibodeau and K.T. Patton, 1996, St. Louis: Mosby-Year Book, Inc. Copyright 1996 from Mosby-Year Book, Inc. Reprinted with permission.

Blood and Lymphatic Supply. Blood is supplied to the thyroid gland from paired superior thyroid arteries that arise from the external carotids, and two inferior thyroid arteries that stem from the thyrocervical trunk. Most individuals possess a fifth vessel called the thyroid ima, which originates from the aortic arch and enters the isthmus inferiorly (Litwack-Saleh, 1992). The thyroid gland is drained by three pairs of vessels: the superior, middle and inferior thyroid veins. These veins extend from a plexus formed on the surface of the gland. The lymphatic drainage of the thyroid gland is by way of the isthmus and Delphian (prelaryngeal) node medially and the paratracheal and deep cervical nodes laterally.

Nerve Supply. The thyroid gland receives its innervation primarily by the superior laryngeal nerves (SLN) and the recurrent laryngeal nerves (RLN). The posterior lateral portions of each lobe of the thyroid gland lie in extreme close proximity to each RLN. The SLNs lie in close proximity to the superior thyroid artery and bifurcate into the internal and external branches. The internal branch of the SLN is sensory and supplies sensation to the larynx above the level of the vocal cords. The SLN also has branches to the base of the tongue. The external branch of the SLN innervates the cricothyroid muscles, which tense the vocal cords.
The path of the RLN follows a different course on each side of the body (Linder, 1989). On the right, the RLN exits the right vagus nerve and loops under the right subclavian vein, travels through the tracheoesophageal groove, and pierces the cricothyroid membrane posteriorly. Conversely, the left RLN is a branch of the left vagus nerve; it loops around the aorta and courses along the tracheoesophageal groove, entering the larynx through the posterior cricothyroid membrane. Because of its longer course, the left RLN is more vulnerable to disease and traumatic injury than the right RLN. The RLNs supply motor innervation to the intrinsic laryngeal muscles. These muscles assist in changing the position of the cricoid, arytenoid, and thyroid cartilages, thus affecting both the tension and length of the vocal cords. The RLN also supplies sensory innervation to the larynx below the level of the vocal cords.

Secretory Function. The primary function of the thyroid gland is to secrete two hormones, thyroxine (T4) and triiodothyronine (T3) (Johnson, 1995). Figure 2 illustrates the secretory function of the thyroid and associated organs. These thyroid hormones serve several purposes that include (a) regulating carbohydrate and lipid metabolism, (b) stimulating oxygen consumption by cells, and (c) controlling growth and development. The production and secretion of thyroid hormones by the thyroid gland are controlled by the thyroid stimulating hormone (TSH) produced by the pituitary gland. TSH is, in turn, regulated by the thyroid-releasing hormone (TRH) secreted from the hypothalamus. Iodine is necessary to synthesize thyroid hormones. Ingested iodine is absorbed into the circulatory system and stored in the thyroid before being converted into thyroid hormones.

FIGURE 2: Regulation of the thyroid gland's secretory function.

Parathyroid Glands. The parathyroid glands are small pieces of reddish-brown tissue that lie on both sides of the thyroid gland. While most individuals possess four parathyroid glands, two superior and two inferior, total numbers of parathyroid glands vary among individuals. These glands are responsible for producing parathyroid hormone, which, along with vitamin D, regulate calcium and phosphorus concentrations in the body. Compromise of the vascular system to the parathyroids during thyroid surgery may result in ischemia and subsequent transient hypocalcemia. Since the inadvertent removal of the parathyroid glands may result in severe tetany and death, care must be taken by the surgeon to identify and preserve the parathyroid glands during surgery.

ADVANCES IN DIAGNOSIS AND MEDICAL TREATMENT

Surgical management of the thyroid disease has changed significantly over the course of the twentieth century. Advances in the development of tests used to diagnose thyroid disease have provided for adequate treatment and control of functional problems of the thyroid. Various blood tests, imaging studies, scans, and needle aspirations have greatly facilitated the diagnosis and treatment of patients with thyroid disease.

Advances have also occurred in the medical treatment of thyroid disease. For instance, radioactive iodine and antithyroid medications are now used instead of surgery to treat hyperthyroidism, and thyroxine is used to treat hypothyroidism or goiter in the euthyroid patient (Johnson, 1995). As a result, surgery is usually performed because of structural problems, such as benign or malignant nodules of the thyroid gland, or large obstructing goiters. Surgery may also be indicated in patients diagnosed with hyperthyroidism who are not suitable for or responsive to medical control of their condition.

POTENTIAL COMPLICATIONS AFTER THYROID SURGERY

Numerous complications may arise following surgical removal of the thyroid gland. These problems often result from either the surgical technique or from metabolic disturbances. Although the incidence of these complications is low, some problems are seen more frequently than others (Netterville & Ossoff, 1990). Primary complications associated with thyroid disease include recurrent laryngeal nerve injury, parathyroid deficit, and post-operative bleeding. Problems less frequently seen are thyroid storm, infection, sympathetic nerve injury, and chylous fistula. While prevention of these complications is a primary goal during thyroid surgery, early recognition and management by the health care team is essential for the safe recovery of the patient.

Laryngeal Nerve Injury
Injury that results from severing, clamping, compressing, or stretching either the RLN or SLN during thyroid surgery may result in severe untoward sequelae for the patient. Varying degrees of symptoms result depending on the combination of SLN and RLN injury. Bilateral RLN injury is a severe life-threatening complication that results in airway obstruction and requires immediate attention. In this condition, both vocal cords remain in a median or paramedian position. As a result, the patient exhibits inspiratory stridor, dyspnea, tachypnea, and nasal flaring, although the voice is near normal.
Unilateral RLN injury causes the ipsilateral vocal cord to remain in the median or paramedian position. The voice may be hoarse and breathy. The patient's cough is weak, and aspiration may occur. Aspiration is more likely to be a problem when combined with SLN injury (Fredrickson & Paniello, 1993). Damage to the SLN affects voice pitch. Since the cord is unable to lengthen and tense, the voice is low in pitch and breathy in quality. Combinations of RLN and SLN injury may occur with varying degrees of severity of symptoms.

Parathyroid Deficit
Hypoparathyroidism is another complication that may occur following thyroid surgery. Injury to the parathyroid glands may result from excision of the gland(s) during surgery, devascularization of the glands, or destruction from capsular hematoma. This complication manifests itself as hypocalcemia and is usually transient. While the patient may be initially asymptomatic after surgery, symptoms eventually occur 24 to 72 hours post-operatively (Litwack-Saleh, 1992). The patient may complain of numbness and tingling of the hands, feet, and lips. If calcium levels are not restored, seizures and laryngeal stridor are imminent.

Postoperative Bleeding
Postoperative hemorrhage may result from vascular abnormalities of the patient, or a loosened tie around a ligated vessel. If not controlled, bleeding in the neck space may lead to tracheal compression and subsequent airway obstruction. To minimize this complication, a drain is usually placed in the surgical site and is removed once oozing from the site has stopped and the risk of hemorrhage has decreased.

Infrequent Postoperative Complications
Some postoperative complications, such as sympathetic nerve injury, chylous fistula, infection, and thyroid storm, have decreased in incidence over the past several years. The decrease is associated with a better understanding of thyroid anatomy, as well as advances in the medical treatment of thyroid disease (Netterville & Ossoff, 1990). Regardless of their incidence, the nurse must be aware of symptoms early in the postoperative phase of recovery.

Injury to the sympathetic chain from stretching or compression during thyroid surgery may result in the development of Horner's syndrome. This condition is characterized by such symptoms as contraction of the pupil, partial ptosis of the eyelid, and anhydrosis of the ipsilateral side.

Damage to the thoracic duct during thyroid surgery may result in a chylous fistula. This complication manifests itself by the presence of profuse and continuous drainage of chyle (a milky or opaque fluid) from the operative wound.

With advances in the development of antibiotics, the incidence of postoperative infection is rarely seen following thyroid surgery. However, if infection does occur, appropriate antibiotic therapy and increased wound care would be implemented.

Thyroid storm is considered a toxic state resulting from hyperactivity of the thyroid gland. It occurs from surgical manipulation of the thyroid gland that is subjected to stress, and/or thyroid activity that has not been controlled preoperatively with medications. Intraoperatively, the patient develops fever and tachycardia. An awake patient may display agitation, disorientation, frequent watery stools, and congestive heart failure. If not medically treated, thyroid storm may progress to coma and death.

NURSING ASSESSMENT AND INTERVENTIONS
Preoperative Nursing Care
A thorough understanding of the potential complications following thyroid surgery can provide the nurse with a focus during the initial nursing assessment as well as the postoperative period. It is vital that patient teaching begin prior to hospital admission, following the initial diagnosis by the physician. The preoperative assessment should include an anesthesia consult as well as the evaluation of all diagnostic tests conducted on the patient. During this time the surgeon should review the risks of thyroid surgery with the patient; informed consent must be obtained.

The nurse should conduct a thorough nursing assessment on the patient. This assessment consists of detailed data describing both physical and psychosocial aspects of the patient. Essential information should include the patient's cardiac and respiratory status, muscle strength, emotional state, elimination pattern, skin condition, weight history, and voice quality.

Often, patients diagnosed with hyperthyroid conditions have been evaluated and treated medically with successful control of thyroid hormone levels and their metabolic state. Characteristics of a hypermetabolic state may include such symptoms as the following: increased pulse and blood pressure, palpitations, weakness, nervousness and agitation, frequent watery stools, find moist skin, and weight loss.

Patients diagnosed with thyroid disease may experience anxiety preoperatively related to their anticipation of the surgical procedure. Some patients may express concern about the cosmetic impact of the surgery. Whatever the concern, the nurse should discuss these feelings with the patient preoperatively and provide appropriate interventions to help reduce stress.

Preoperatively, the nurse should carefully assess the condition of the patient's skin, as well as the voice quality. Patients diagnosed with a hyperthyroid state may have thin, textured skin and edema of the lower extremities. Such problems may place these patients at risk for injury intraoperatively and for problems with wound healing and infection postoperatively. In addition, preoperative assessment of voice quality is essential postoperatively in detecting early evidence of nerve injury, such as hoarseness.

Various degrees of airway obstruction and dysphagia may be present preoperatively in patients diagnosed with thyroid problems. An enlarged thyroid gland may compress the structures in the neck and interfere with their function. Preoperatively, the nurse should document any enlargement noted in the patient's neck, and/or complaints made by the patient concerning difficulty swallowing or breathing. The anesthesia care provider will need to evaluate the patient's airway for expected difficulties with intubation that may be the result of tracheal compression or deviation. Assessment for evidence of cervical spine injury or disease is also necessary to prevent complications related to positioning in the operating room. Hyperextension of the neck using a shoulder roll and head rest allows the surgeon optimal visualization of the surgical field. This is generally the standard position for thyroid surgery, but may present a risk for injury to the cervical spine if precautions are not taken.

Finally, diagnostic test results should be reviewed and included in the preoperative assessment. Possible laboratory tests include a complete blood count, thyroid hormone levels, and serum calcium and phophorus concentrations. The results of other tests, such as imaging studies and a fine needle aspiration (FNA) biopsy, often performed on patients with thyroid nodules, allow the nurse to evaluate the thyroid diagnosis preoperatively and to anticipate potential problems that may occur postoperatively.

Postoperative Nursing Care
The postoperative phase begins when the patient arrives in the postanesthesia care unit. The nurse must be alert to postanesthetic priorities, carefully monitoring the patient's cardiopulmonary status, neurological status, comfort level, surgical wound condition, and metabolic state. The nurse should monitor the patient's level of consciousness, vital signs, EKG, and pulse oximetry. The nurse should assess the patient's pain level and provide individualized management as ordered.

Airway obstruction in the thyroidectomy patient immediately following surgery may be the result of several conditions. These include laryngospasm, laryngeal edema due to surgical manipulation, laryngeal obstruction due to bilateral vocal cord paralysis, or tracheal compression from hematoma formation. The nurse should continually assess and document the patient's airway patency, oxygen saturation levels, and respiratory status. Bleeding should be carefully noted, both on the patient's dressing and from the surgical drains. The nurse should document the presence of drains, the amount and consistency of drainage, and the functioning status of the equipment. The nurse should monitor the patient's dressing for changes in drainage and tightness. The nurse should also note the presence of neck swelling (edema) around the edge of the neck dressing. A progressively enlarging mass noted in the neck of a thyroidectomy patient without a dressing may suggest the formation of a hematoma. The presence of hypotension and tachycardia may also signify bleeding. The availability of and quick access to a tracheostomy tray are vital.

The nurse should also observe the thyroidectomy patient for evidence of metabolic disturbances, such as thyroid storm and hypocalcemia. Thyroid storm, described above, usually occurs intraoperatively or up to 18 hours postoperatively (Litwack-Saleh, 1992). Treatment is directed toward identification and control of symptoms.

Hypocalcemia symptoms are usually manifested 24 to 72 hours after thyroid surgery (Litwack-Saleh, 1992). The nurse should assess the patient for any numbness or tingling around the lips or hands. Neuromuscular irritability, indicating hypocalcemia and potential tetany, may be demonstrated in the patient by two tests, the Trousseau and Chvostek. A positive Trousseau's sign is carpal spasm induced by arterial occlusion of the arm with a blood pressure cuff (Figure 3), and a positive Chvostek's sign is facial nerve irritability/spasms elicited by tapping the nerve (Figure 4). Since severe hypocalcemia can lead to laryngeal stridor and convulsions, the nurse should immediately report any symptoms to the physician. Serum calcium level measurements are usually ordered daily, especially if the patient is symptomatic. Tetany is usually relieved with calcium replacements, such as 10% calcium gluconate solution administered intravenously.

Because of the potential for laryngeal nerve damage intraoperatively, the nurse should evaluate the patient's voice quality and swallowing postoperatively. Any change in voice or problems with aspiration should be reported to the physician and documented. If needed, flexible laryngoscopy at the bedside or in the office can assist the physician in determining vocal cord function and possible treatment.

Discharge Teaching
Discharge teaching for the patient following a thyroidectomy should include information regarding the signs and symptoms of potential complications as previously described. It is also important to include information about how and when to contact the physician, plus written and verbal information regarding medications, wound care, nutrition, and follow-up visits with the physician. The nurse must be sure that the patient demonstrates an understanding of all aspects of home care. The family and significant others should be included in discharge teaching.

CONCLUSION
It is imperative that patients undergoing thyroid surgery be informed through all stages of the surgical experience. Teaching provided by the nurse should begin at the time of diagnosis and continue throughout the postoperative period to discharge. A well-informed patient, combined with an astute ORL nurse, can facilitate a positive outcome, thereby helping to meet the goal of cost-effective, quality patient care.

REFERENCES

• Coffey, A., & Petti, G. (1993), Endocrinology. In B. Bailey, J. Johnson, R. Kohut, H. Pillsbury, & M. Tardy (Eds.), Head and neck surgery-otolaryngology (pp.135-148). Philadelphia: J. B. Lippincott Co.
• Fredrickson, J., & Paniello, R. (1993). Neoplasms of the thyroid. In C. Cummings, J. Fredrickson, L. Haiker, C. Krause & D. Schuler (Eds.), Otolaryngology-head and neck surgery (pp. 2436-2451). Philadelphia: W. B. Saunders. Co.
• Johnson, J. (1995). Thyroid and parathyroid surgery. In M. Meeker & J. Rothrock (Eds.), Alexander's care of the patient in surgery (pp. 548-558). St. Louis: Mosby-Year Book.
• Linder, H. H. (1989). The thyroid gland. Clinical anatomy (pp. 132-140). East Norwalk, Connecticut: Appleton & Lang.
• Litwack-Saleh, K. (1992). Practical points in the care of the patient post-thyroid surgery. Journal of Post Anesthesia Nursing, 7, 404-406.
• Netterville, J., & Ossoff, R. (1990). Evaluation and treatment of complications of thyroid and parathyroid surgery. Otolaryngologic Clinics of North America, 23, 529-551.
• Thibodeau, G. A. & Patton, K. T. Anatomy and Physiology (p. 558). St. Louis: Mosby-Year Book.

ABOUT THE AUTHORS
Ann McKennis, RN, CNOR, CORLN, and Carolyn Waddington, RN, BSN, CORLN are both experienced Staff Nurses in the Otolaryngology Operating Rooms, The Methodist Hospital, Houston, Texas. Ann received her nursing diploma from Harper School of Nursing in Detroit, Michigan. Carolyn obtained her BSN from Texas Women's University. Both authors are certified ORL Nurses.

ABOUT THE CONTINUING EDUCATION FEATURE EDITOR
Joan Such Lockhart, PhD, RN, CORLN, CE Feature Editor, is currently an Associate Professor and Chair of the BSN Program at Duquesne University School of Nursing in Pittsburgh, PA. She received her PhD, MNEd, and BSN from the University of Pittsburgh School of Nursing, and diploma from Presbyterian-University Hospital School of Nursing. Joan also has a minor in curriculum and supervision from the School of Education.