DAANCE - Dental Anesthesia Assistant National Certification Examination Office Anesthesia Emergencies Questions and Answers 1 — Questions and Answers
Question 1: A patient under deep sedation suddenly develops a high-pitched inspiratory stridor, exhibits paradoxical chest movement (a "rocking" pattern), and has a rapidly decreasing oxygen saturation. These signs are most characteristic of which airway emergency?
- Bronchospasm
- Laryngospasm (Correct answer)
- Aspiration of foreign body
- Hyperventilation
Correct answer: Laryngospasm
The classic signs of laryngospasm, a protective reflex closure of the vocal cords, include inspiratory stridor (a high-pitched 'crowing' sound), paradoxical chest/abdominal movements as the patient struggles to breathe against a closed glottis, and rapid oxygen desaturation. Definitive treatment, if positive pressure ventilation fails, involves administering succinylcholine to paralyze the laryngeal muscles.
Question 2: While monitoring a sedated patient with a history of asthma, the dental anesthesia assistant notes the capnography waveform has changed from its normal rectangular shape to one resembling a "shark fin." This change is most indicative of what respiratory event?
- Partial airway obstruction by the tongue
- Esophageal intubation
- Bronchospasm (Correct answer)
- Apnea
Correct answer: Bronchospasm
A "shark fin" shaped capnogram is a classic sign of bronchospasm. The obstruction in the smaller airways causes a prolonged and uneven emptying of the alveoli, resulting in a slow, sloped upstroke on the waveform instead of the normal sharp, vertical rise.
Question 3: Minutes after IV drug administration, a patient develops diffuse hives, respiratory distress, and a blood pressure drop to 70/40 mmHg. Which medication is the most critical and immediate first-line treatment for this condition?
- Intravenous Diphenhydramine 50 mg
- Intramuscular Epinephrine 0.3-0.5 mg (Correct answer)
- Intravenous Dexamethasone 8 mg
- Albuterol inhaler, 2 puffs
Correct answer: Intramuscular Epinephrine 0.3-0.5 mg
The patient is exhibiting signs of anaphylaxis, a severe, life-threatening allergic reaction. Intramuscular epinephrine is the essential first-line treatment that must be administered immediately to reverse bronchoconstriction and severe hypotension (cardiovascular collapse). While antihistamines, corticosteroids, and bronchodilators are used as adjunctive therapies, they are not the primary life-saving intervention.
Question 4: A patient undergoing general anesthesia with sevoflurane develops masseter muscle rigidity, tachycardia, and a sudden, sustained rise in end-tidal CO2 that does not respond to increased ventilation. Which of the following emergencies should be suspected?
- Anaphylaxis
- Adrenal crisis
- Thyroid storm
- Malignant Hyperthermia (Correct answer)
Correct answer: Malignant Hyperthermia
The triad of tachycardia, muscle rigidity, and especially an abrupt, unexplained rise in end-tidal CO2 (hypercarbia) are the earliest and most specific signs of a malignant hyperthermia (MH) crisis. MH is a hypermetabolic state triggered by certain anesthetic agents in susceptible individuals. While a high fever is a hallmark sign, it is often a later development.
Question 5: Shortly after receiving several injections of local anesthetic, a conscious patient becomes agitated and complains of tinnitus, a metallic taste, and circumoral numbness. These are classic early signs of which systemic emergency?
- Local Anesthetic Systemic Toxicity (LAST) (Correct answer)
- Vasovagal Syncope
- An allergic reaction to epinephrine
- Hyperventilation syndrome
Correct answer: Local Anesthetic Systemic Toxicity (LAST)
The initial signs of Local Anesthetic Systemic Toxicity (LAST) often involve the central nervous system (CNS). Prodromal symptoms include agitation, confusion, tinnitus (ringing in the ears), a metallic taste, and numbness around the mouth (circumoral numbness). Recognizing these early signs is crucial for stopping the administration of the anesthetic and preventing progression to more severe symptoms like seizures and cardiovascular collapse.
Question 6: A sedated diabetic patient who took their morning insulin but was NPO for a procedure becomes tachycardic, diaphoretic, and confused. If this patient is unable to take anything by mouth, what is the most appropriate immediate intervention?
- Administering a rapid IV fluid bolus of normal saline
- Administering supplemental oxygen via a non-rebreather mask
- Checking a finger-stick blood glucose and administering IV dextrose or IM glucagon (Correct answer)
- Administering an anti-anxiety medication like midazolam
Correct answer: Checking a finger-stick blood glucose and administering IV dextrose or IM glucagon
The signs of tachycardia, diaphoresis (sweating), and confusion in a fasting diabetic patient are highly suggestive of hypoglycemia (low blood sugar). The immediate priority is to confirm the diagnosis with a glucometer reading and correct the low blood sugar. Since the patient cannot take oral glucose, intravenous dextrose (D50) or intramuscular glucagon is the indicated treatment.
