Case Title: Thyroid Storm in a Patient Presenting for Laparoscopic Appendectomy
Patient Name: Marcy Marshfield
Scenario Name: Thyroid Storm
Simulation Developers: Ann Willemsen-Dunlap, CRNA, PhD, Paul Leonard, MD, PhD, and Johann Cutkomp, BLS
Dates of Development: May to July, 2010
Target Learners—Anesthesia Trainees
Thyroid storm is a rare, life-threatening complication of poorly controlled or uncontrolled hyperthyroidism. The mortality rate ranges between 10% and 30% with treatment and may increase to 75% if left untreated.1 This condition classically occurred during the early postoperative period in hyperthyroid patients who were prepared for thyroidectomy with potassium iodide alone. Such patients were often not euthyroid and would not be considered by contemporary standards to have been adequately prepared for surgery.2 Improved patient management practices in the period preceding thyroidectomy have greatly decreased the number of cases attributed to surgical resection of the thyroid gland.2 Thyroid storm may also be precipitated by a number of physiologic stressors, including infection, physical and emotional stress, surgery, trauma, diabetic ketoacidosis, and childbirth.3 Anesthesia providers routinely care for patients who may be predisposed to developing thyroid storm due to each of these stressors and should be familiar with measures for early treatment and stabilization.
Clinicians in various settings may encounter patients experiencing severe exacerbation of hyperthyroidism; thus, healthcare providers in many specialties should be familiar with diagnosis and early treatment of this condition. In addition, caring safely and effectively for the patient experiencing amedical crisis such as thyroid storm represents a dynamic situation that requires good communication and effective use of other teamwork skills. This scenario may be modified into one appropriate for interprofessional groups of healthcare providers on general medical and surgical floors as well as in medical and surgical intensive care units. It may also be developed into a scenario requiring patient transfer between medical and surgical floors and intensive care units. The latter scenario offers an opportunity for healthcare providers to rehearse key teamwork skills with particular emphasis on communication and patient handoff.
These general competencies from the Accreditation Committee of Graduate Medical Education (ACGME) will be met in the following ways:
- Medical knowledge: At the conclusion of this scenario, learners will be able to identify signs and symptoms of thyroid storm as well as be able to list several precipitating causes of the condition. They will be able to discuss the pathophysiology of thyroid storm, including the feedback loop(s) that normally control thyroid function. They will be able to describe the rationale and pharmacology relating to early treatment of this condition. Learners will be able to verbalize rationale for initiating supportive care without waiting for confirmatory laboratory results. With the guidance/assistance of the faculty member facilitating the simulation, learners will manage a patient with thyroid storm.
- Patient care: At the conclusion of this scenario, learners will be able to discuss strategies for managing a disinhibited patient with compassion and care.
- Practice-based learning and improvement: Learners will practice forming a differential diagnosis that includes both common and rare elements of thyroid storm as well as practicing pattern recognition of common and rare elements of this disease. The learner will also rehearse the initiation of supportive care for the patient in thyroid storm. Learners will be able to discuss and implement safe and compassionate care of a disinhibited patient.
- Interpersonal and communication skills: During debriefing, learners will be able to discuss three strategies to help enable effective teamwork and patient care during a medical crisis.
- Professionalism: During the scenario, learners will rehearse professional behavior during a medical crisis that presents both clinical and interpersonal challenges by managing a patient who is disinhibited due to a critical pathologic condition. During debriefing, learners will practice treating each other with respect while contributing to the creation and maintenance of a safe learning environment.
- Systems-based practice: The learner will discuss strategies for identifying resources needed as well as recruiting adequate and appropriate help during a medical crisis.
Guided Study Questions
- Describe the feedback loop(s) that control thyroid function.
- Discuss the key intracellular and mechanism(s) responsible for the action of thyroid hormone.
- Identify signs and symptoms of thyroid storm, and how it may be differentiated from malignant hyperthermia and other processes.
- List five precipitating causes of thyroid storm.
- Describe immediate treatment priorities and their rationale.
- Discuss management options and their indications for the severely agitated and disinhibited patient.
When the desired learning objectives are chiefly pathophysiology and treatment, debriefing may be done by pausing the mannequin to discuss key points during the course of the scenario (an interrupted flow model). The simulation then resembles a problem-based learning discussion (PBLD), although the simulation environment encourages awareness of patient status and mechanics of implementing interventions. When objectives related to the full set of ACGME competencies that are desired, the scenario runs from start to completion followed by debriefing, but clues and directions to encourage eventual correct diagnosis may be provided by the instructor via headset link to a confederate (a continuous flow model).
Experience With the Scenario
Our laboratory began using this scenario in 2006. Consistent with the older presentation of perioperative thyroid storm, the case stem was that of a middle-aged patient who had undergone a partial thyroidectomy. Approximately 40 trainees, all student registered nurse anesthetists and anesthesia residents, experienced this scenario in groups of various sizes. Diagnostic considerations other than thyroid storm identified by trainees included malignant hyperthermia, sepsis, myocardial infarction, and cerebrovascular accident. The faculty facilitator frequently needed to direct attention to the nature of the surgery, available diagnostic tests, and review the time course of postthyroidectomy thyroid storm. Conversely, when trainees quickly identified thyroid storm as a causative agent, they most often did so to the exclusion of all other diagnoses. In the majority of cases, trainees needed significant help in deciding on and delivering treatments.
When adding the additional objectives to this scenario in mid-2010, the presentation was updated to relate to stress from another surgery. We have less experience with participant behavior in this version of the scenario. Early performance supports our expectation that trainees’ ability to formulate the correct diagnosis and begin appropriate treatment is highly dependent on their understanding that the processes observed in the postanesthesia care unit (PACU) actually began before the patient’s admission for surgery.
METI HPS (Table 1).
Intrascenario Laboratory Results
7.45/33/93/HCO3 = 22, H&H = 12 and 36, glucose = 120.
Set-up time for the scenario is approximately 15 minutes. The prebriefing requires approximately 5 minutes. The simulation itself requires 15 to 20 minutes to run as a team exercise. Debriefing a team exercise generally requires two to three times longer than the scenario itself. Conducting the exercise as a team scenario will increase the likelihood that all of the ACGME competencies are addressed. If the simulation is run as an exercise for one or two learners using an interrupted flow model, the scenario and debriefing together will require approximately 30 to 35 minutes.
The patient is a 38-year-old woman who underwent an emergency laparoscopic appendectomy. The patient’s medical record reveals that she is 5 ft 9 in and 53 kg. She has a latex allergy secondary to occupational exposure. She has no known drug allergies. Her medical and surgical history is insignificant except for mild exercise-induced asthma. The patient had been training for half marathons until her present illness. The preoperative anesthesia assessment states that her asthma has not been a problem for several years. The patient reported sudden onset of periumbilical pain approximately 24 hours ago that was followed by multiple episodes of vomiting. The pain continued until this morning, at which time she presented to an urgent care clinic. The patient was subsequently referred to this hospital. Preoperative laboratory values were significant for a white blood cell (WBC) of 17,000. The H&H were 13.9 and 40. A urine pregnancy test was negative.
Preoperative vital signs on admission to Day of Surgery Admissions (DOSA): temperature, 38.2°C; heart rate (HR), 122; BP, 115/80; respiratory rate, 22; and SpO2, 98% on room air. The DOSA nursing note says the patient reported being very anxious about the surgery, had not been sleeping well for the last month, and that she has had an unintentional 2.5 kg weight loss over the past 2 to 3 weeks. A fine tremor, mild hyperreflexia, dry skin, and oral mucosa were noted on the preoperative nursing assessment. Patient has been nothing per os (NPO) since 2 AM this morning. Her last emesis occurred at 8 AM.
The anesthesia team started an 18 peripheral IV (PIV) in the right hand and administered a 250 mL lacted ringers (LR) bolus in the preoperative holding area. The patient received 2 mg of midazolam at that time. She started to become disinhibited on the way to the operating room (OR). Preinduction vitals in the OR were HR of 115, BP of 140/88, and SpO2 of 98% on room air. The PACU nurse reported that the patient received an additional 2 mg of midazolam and 100 μg of fentanyl in the OR with a subsequent increase in agitation. The patient received 100 mg of propofol and 40 mg of rocuronium at induction with a precipitous drop in blood pressure to 50/28. The hypotension was responsive to 300 μg of phenylephrine administered in divided doses. She was intubated without difficulty. Maintenance anesthesia included oxygen and air at 0.30 FiO2, sevoflurane 1.6%, 30 mg of ketamine, and 30 mg of ketorolac each before incision; 8 mg of Decadron, also at the beginning of the case; and rocuronium boluses to maintain one twitch in a train of four. Reversal of neuromuscular blockade at the end of the case was accomplished with 0.6 mg of glycopyrrolate and 3 mg of neostigmine. Ondansetron (4 mg) was administered before emergence. The patient was extubated and admitted to PACU breathing spontaneously and responsive to verbal stimuli. She has since become very agitated and has been requiring manual restraint. The PACU nurse is present with the patient.
Learner and Faculty/Coordinator Information
Faculty, operator, and trainee need to clarify ahead of time whether there will be an actor as voice of patient or whether faculty will be voice of patient while standing at the bedside. If there is no actor, faculty will also need to describe the actions of the patient, eg, “The patient has become confused and agitated in the PACU and is thrashing in bed.” Alternatively, faculty may describe to trainees both what the patient is doing and saying eg, “the patient is in PACU thrashing in bed and confused. She says she needs to get out of there. She is oriented to person only.” Faculty will instruct learners during the prebriefing whether or not he or she will be expected to initiate infusions of simulated drugs, and whether they will be using a live defibrillator or a training model. Trainees will generally be required to administer simulated bolus doses of medications. Facilitators may also consider using an actress for this scenario, provided appropriate precautions are taken. Such precautions include using only defibrillator trainers with a live actress, realistically taping intravenous (IV) tubing in place, then using extensions to divert infusions into a container under the bed, and securing IV training pads to the actress’s arms to provide a place for additional IV insertions and drawing labs. Specific precautions will be shared with the learners during the presimulation briefing.
Script for PACU registered nurse if a confederate: When asked, the nurse provides information he or she received from the anesthesia provider who cared for the patient in the OR. This information will reiterate what the learner read in the case stem: “Patient is a 38-year-old female who had a laparoscopic appendectomy. She was very anxious and agitated before she went to the OR. She received a total of 4 mg of midazolam, 100 μg of fentanyl, and 100 mg of propofol. After the propofol, her blood pressure dropped to 52/28, but she recovered after she received a total of 300 μg of phenylephrine and some fluid. In fact, the anesthesia team bolused her with 250 mL of lactated Ringers before induction. She did OK otherwise through the case, but she’s been absolutely wild since she woke up. The preop note from Day of Surgery Admissions says she was unusually anxious as they were getting her ready to go to the OR.”
Faculty/Operator Information (Not to Be Shared With Learner)
This scenario may be done with either a mannequin patient or an actress.
Faculty and operator agree ahead of time on the definition of effective therapy for atrial fibrillation with rapid ventricular response.
Two methods of helping the team determine the correct diagnosis: establishing a one-way communication link by having a participant or a confederate wear a headset allows the scenario director or operator to provide additional facts or direction that will move the scenario forward. Asking the PACU nurse (confederate or learner) to remind everyone that symptoms started before surgery may encourage participants consider diagnoses in addition to malignant hyperthermia and sepsis. Facilitators may also debrief the challenge of diagnosing a rare condition as a teamwork issue as participants are all responsible for putting forth both their ideas and their concerns during the scenario. Such an approach is frequently successful in eliciting different pieces of information that allows the team to arrive at the diagnosis during the debriefing.
PATIENT BACKGROUND AND BASELINE STATE
A 38-year-old woman with likely appendicitis underwent a laparoscopic appendectomy. Patient began having abdominal pain approximately 24 hours ago, followed by onset of vomiting. Patient described the pain as coming on very suddenly. Abdominal ultrasound revealed a thickened appendix wall without evidence of appendolith. Patient has a history of exercise-induced asthma, for which she uses an unknown inhaler. She denied problems over the past 2 to 3 years.
Exercise-induced asthma. Quiescent for past several years.
Normal spontaneous vaginal delivery (NSVD) × 1.
Cesarean section × 1 under spinal anesthetic.
Married, two children, aged 9 and 6 years, no tobacco, occasional glass of wine with dinner, and no illicit drugs. Patient is a hair stylist, currently working part-time.
Preoperative Review of Systems
Central nervous system: anxious and agitated; oriented ×3. Fine tremor and mild hyperreflexia present. Negative for stroke, migraine, paresthesia, and weakness.
Cardiovascular: negative for hypertension, coronary artery disease, valvular disease, and hypertension.
Pulmonary: history of exercise-induced asthma. No problems for several years. Negative for recent upper respiratory infection (URI) and shortness of breath (SOB).
Renal/hepatic: negative for renal failure, cirrhosis, and jaundice.
Gastrointestinal: nausea and vomiting for past 24 hours, diffuse abdominal pain that localizes to McBurny’s point.
Endocrine: negative for diabetes.
Hematology and coagulation: Negative for easy bruising or bleeding. H&H: 13.9 and 40; WBC, 17,000.
Reproductive: negative pregnancy test.
Current Medications and Allergies
Latex allergy due to occupational exposure from wearing gloves.
No known drug allergies (NKDA).
Birth control pills.
Preoperative Physical Examination
General: thin, slightly flushed, anxious-appearing female.
Weight/height: 5 ft 9 in /53 kg.
Vital signs: preoperative admission vital signs—temperature, 38.2°C; HR, 122; BP, 115/80; respiratory rate, 22; and SpO2, 98%.
Airway: native dentition intact, Mallampati class I, three fingerbreadths thyromental distance, and full range of motion in neck.
Lungs: clear to auscultation.
Heart: regular rate and rhythm, no gallops, murmurs, or rub. Tachycardia to 120 beats per minute.
Abdomen: mild distension with diffuse abdominal pain that localizes to right.
Preoperative Laboratory, Radiology, and Other Relevant Studies
Hemoglobin and hematocrit (H&H): 13.9 and 40, WBC 17,000.
Chest X-ray (CXR): none.
Electrocardiogram (EKG): none.
Ultrasound evidence of appendolith. Negative urine pregnancy test.
Baseline Simulator State: What Underlying Alterations in Physiology Will This Patient Have?
Vitals in the PACU: neuro—very agitated, requires constant supervision because of restlessness and agitation; not oriented to place or time; and minimally cooperative. Moves all extremities, pupils equal, and reactive to light.
Respiratory: clear to auscultation.
Cardiovascular: tachycardic, irregular rhythm.
Gastrointestinal: mild abdominal distension with dry, intact dressing on right lower quadrant.
Genitourinary: no Foley catheter.
Metabolic: respiratory alkalosis on arterial blood gas (ABG) if one is obtained in PACU.
Environmental: N/A (Table 2).
- Medical knowledge
- a. Signs and symptoms of thyroid storm include tachycardia, increased temperature, extreme anxiety and agitation, possible cardiac dysrhythmias, and hypotension.
- b. Differential diagnoses in patients with postoperative confusion, tachycardia, and elevated temperature in the PACU.
- i. Hypoxia, hypovolemia, pain, sepsis, central nervous system, serotonin syndrome, cholinergic and adrenergic crisis, neuroleptic malignant syndrome, and malignant hyperthermia.
- ii. Importance of blood gas in distinguishing thyroid storm for malignant hyperthermia.
- 1. In malignant hyperthermia, both respiratory and metabolic acidosis are typically more profound than in thyroid storm.
- iii. Importance of confirming patient history with special attention to medications taken.
- c. Precipitating causes of hyperthyroidism include undiagnosed or incompletely treated hyperthyroidism, infection, surgery, emotional stress, trauma, manipulation of the thyroid gland, exogenous intake of T3 or T4, and cessation of antithyroid drugs.
- d. Pathophysiology of hyperthyroidism.
- e. Pharmacology of drugs used for immediate treatment of hyperthyroidism; expected treatment after patient stabilization.
- f. Indications for electrical therapy to treat dysrhythmias induced by hyperthyroidism.
- i. Management of atrial fibrillation in a patient with heart rate >150 bpm and who has progressed from a stable condition to an unstable condition as defined by American Heart Association algorithms.
- g. Signs and symptoms of high-output cardiac failure induced by hyperthyroidism and thyroid storm.
- h. Rationale for proceeding with treatment for thyroid storm without waiting for confirmatory laboratory tests.
- i. Indications for physical restraint in the acute care setting.
- j. Choosing between sedation and physical restraint in the acute care setting (Figure 1).
Interpersonal and communication skills.
- a. Signs and symptoms considered in forming a differential diagnosis for this case.
- b. Similarities and differences between malignant hyperthermia, sepsis, and hypoxia.
- c. Rehearsal of initiating care for the patient in thyroid storm and rehearsal of managing the disinhibited patient.
- a. Was a team leader designated?
- b. Were roles clearly assigned?
- c. Did the team develop and maintain a shared mental model of the situation?
- d. Was there a complete and effective patient handoff between primary nurse and clinician(s) entering the scenario?
- e. Was communication between team members both issued and received by the necessary individuals? Was the loop closed between team members?
- f. Did team members treat one another with respect and professionalism during both the scenario and debriefing?
- g. How did team members interact with a disinhibited patient?
- a. The patient in this scenario could become so agitated that she requires physical or chemical restraint. What are your institution’s guidelines for institution such measures?
- b. Where does one find such policies at your institution?
- c. What considerations are there in making the decision to physically or chemically restrain a patient?