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Pain and anxiety control · Oral Surgery · INBDE Patient Cases

Local Anesthesia & Sedation INBDE Patient Cases

By Dr. Isaac Sun, DDS

7 ADA INBDE-format patient cases on local anesthesia & sedation. Each case is a shared patient box (chief complaint, history, medications, allergies, exam) followed by linked multiple-choice questions with full distractor explanations. Practice the way the real exam is structured.

7 patient cases35 linked questionsADA INBDE formatFull distractor explanations

Seven ADA INBDE-format patient cases on local anesthesia and sedation in oral surgery: calculating the weight-based maximum dose for a small child and the cartridge milligram math, using a limited epinephrine dose in a cardiac patient on a nonselective beta-blocker, recognizing and managing local anesthetic systemic toxicity (CNS excitation then depression), methemoglobinemia from prilocaine and benzocaine treated with methylene blue, clarifying a reported anesthetic allergy (true allergy is uncommon and ester-related), a failed inferior alveolar nerve block with supplemental techniques and accessory innervation, and nitrous oxide minimal sedation with 100% oxygen to prevent diffusion hypoxia. Topics include local anesthetic agents and nerve blocks, maximum doses and toxicity, vasoconstrictors, the sedation continuum, and nitrous oxide.

Case Coverage Map
What each case is testing
Numbing a small child safely:
Weight-based maximum dose, why children are highest-risk for overdose, cartridge milligram math, early toxicity signs, and prevention.
Epinephrine in a patient with heart disease:
Limited (not zero) epinephrine, the cardiac dose limit, the nonselective beta-blocker interaction, aspiration, and why a limited dose is preferred.
A seizure shortly after injection:
Local anesthetic systemic toxicity (excitation then depression), likely causes, supportive management, and prevention.
Cyanosis that won't improve with oxygen:
Methemoglobinemia from prilocaine/benzocaine, oxygen-unresponsive cyanosis, methylene blue treatment, and the oxidized-hemoglobin mechanism.
A reported 'allergy' to a numbing agent:
True allergy is uncommon (ester PABA), reactions often vasovagal/epinephrine, amide choice if ester-allergic, and clarifying the history.
A lower molar that won't get numb:
Why mandibular teeth need an IAN block, numb-lip-but-sensitive-tooth, supplemental techniques, and accessory (mylohyoid) innervation.
Nitrous oxide for an anxious patient:
Minimal sedation with nitrous oxide, 100% oxygen to prevent diffusion hypoxia, the sedation continuum, and rapid titratable recovery.
Patient case: Numbing a small child safely
0 of 5 answered, 0 correct
Patient
Male, 5 years old
Chief Complaint
Several teeth to be treated under local anesthesia.
Background and/or Patient History
  • Small child (low body weight)
  • Multiple quadrants planned in one visit
  • Clinician calculating the anesthetic dose
Allergies
NKDA
Medications
  • None
Current Findings
  • Pediatric patient requiring multiple cartridges if not planned carefully
  • Weight-based maximum dose must be respected
  1. Question 1
    Moderate
    The maximum local anesthetic dose for this child is calculated based on:
  2. Question 2
    Moderate
    Children are the highest-risk group for local anesthetic overdose because:
  3. Question 3
    Hard
    If a 2% lidocaine cartridge contains about 36 mg, tracking the dose requires:
  4. Question 4
    Moderate
    If toxicity occurred, the earliest signs would be:
  5. Question 5
    Moderate
    The best prevention strategy in this child is to:

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Patient case: Epinephrine in a patient with heart disease
0 of 5 answered, 0 correct
Patient
Male, 66 years old
Chief Complaint
Extraction; has stable cardiovascular disease.
Background and/or Patient History
  • Stable coronary artery disease
  • Needs effective anesthesia for an extraction
  • Question of whether to use epinephrine
Allergies
NKDA
Medications
  • Beta-blocker
Current Findings
  • Cardiac patient requiring local anesthesia
  • Epinephrine dose and interactions to consider
  1. Question 1
    Moderate
    For this stable cardiac patient, epinephrine in the local anesthetic is generally:
  2. Question 2
    Hard
    The cardiac maximum epinephrine dose is commonly cited as about:
  3. Question 3
    Hard
    This patient's beta-blocker is relevant because nonselective beta-blockers plus epinephrine can cause:
  4. Question 4
    Moderate
    A key technique to reduce systemic epinephrine effect is to:
  5. Question 5
    Moderate
    The reason a limited epinephrine dose is preferred over none is that it:

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Patient case: A seizure shortly after injection
0 of 5 answered, 0 correct
Patient
Female, 30 years old
Chief Complaint
Became agitated then had a brief seizure soon after local anesthetic.
Background and/or Patient History
  • A large volume of anesthetic was given over a short time
  • Patient reported ringing in the ears and agitation, then a brief seizure
  • No prior seizure history
Allergies
NKDA
Medications
  • None
Current Findings
  • Signs consistent with local anesthetic systemic toxicity (CNS excitation)
  • Possible intravascular injection or exceeded dose
  1. Question 1
    Moderate
    Agitation, tinnitus, and a seizure shortly after injection are most consistent with:
  2. Question 2
    Moderate
    If untreated, the toxicity would be expected to progress to:
  3. Question 3
    Moderate
    Two likely contributing causes were:
  4. Question 4
    Moderate
    Immediate management centers on:
  5. Question 5
    Moderate
    Prevention of this event would have included:

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Patient case: Cyanosis that won't improve with oxygen
0 of 5 answered, 0 correct
Patient
Male, 40 years old
Chief Complaint
Turned bluish after anesthesia; oxygen did not help.
Background and/or Patient History
  • Received prilocaine (and topical benzocaine) during the procedure
  • Developed cyanosis (bluish discoloration)
  • Cyanosis did not improve with supplemental oxygen
Allergies
NKDA
Medications
  • None
Current Findings
  • Cyanosis unresponsive to oxygen after prilocaine/benzocaine
  • Pattern consistent with methemoglobinemia
  1. Question 1
    Hard
    Cyanosis that does not improve with oxygen after prilocaine or benzocaine suggests:
  2. Question 2
    Moderate
    The agents classically responsible are:
  3. Question 3
    Hard
    The specific treatment for significant methemoglobinemia is:
  4. Question 4
    Hard
    The reason oxygen alone does not correct the cyanosis is that:
  5. Question 5
    Moderate
    Prevention includes:

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Patient case: A reported 'allergy' to a numbing agent
0 of 5 answered, 0 correct
Patient
Female, 48 years old
Chief Complaint
Reports an allergy to a local anesthetic years ago.
Background and/or Patient History
  • Vague history of a reaction to a dental anesthetic in the past
  • Details suggest a possible ester or a vasovagal/epinephrine response, not confirmed amide allergy
  • Needs anesthesia for treatment
Allergies
Reported 'caine' reaction (unclear)
Medications
  • None
Current Findings
  • Unclear anesthetic allergy history requiring clarification
  • Planning safe anesthesia
  1. Question 1
    Moderate
    True local anesthetic allergy is:
  2. Question 2
    Moderate
    A reported reaction is often actually:
  3. Question 3
    Hard
    If a true ester allergy were confirmed, a reasonable choice is:
  4. Question 4
    Moderate
    The best next step for this unclear history is to:
  5. Question 5
    Easy
    This case illustrates that a documented anesthetic 'allergy' should be:

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Patient case: A lower molar that won't get numb
0 of 5 answered, 0 correct
Patient
Male, 38 years old
Chief Complaint
Lower molar still sensitive after an inferior alveolar nerve block.
Background and/or Patient History
  • Inferior alveolar nerve block given for a mandibular molar
  • Lip is numb but the tooth is still sensitive
  • Considering why the block is incomplete
Allergies
NKDA
Medications
  • None
Current Findings
  • Soft-tissue (lip) signs of a block but inadequate pulpal anesthesia
  • Mandibular molar requiring supplemental technique
  1. Question 1
    Moderate
    Mandibular posterior teeth typically require an IAN block (rather than infiltration) because:
  2. Question 2
    Hard
    A numb lip but a still-sensitive tooth suggests:
  3. Question 3
    Moderate
    A reasonable next step to achieve pulpal anesthesia is:
  4. Question 4
    Hard
    An accessory nerve sometimes implicated in failed mandibular anesthesia is the:
  5. Question 5
    Easy
    The general lesson is that effective anesthesia depends on:

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Patient case: Nitrous oxide for an anxious patient
0 of 5 answered, 0 correct
Patient
Female, 27 years old
Chief Complaint
Very anxious about an extraction; asks about laughing gas.
Background and/or Patient History
  • Healthy, anxious patient
  • Minimal sedation with nitrous oxide and oxygen planned
  • Discussing how it works and its safety
Allergies
NKDA
Medications
  • None
Current Findings
  • Candidate for nitrous oxide minimal sedation
  • Planning safe administration and recovery
  1. Question 1
    Moderate
    Nitrous oxide and oxygen provides:
  2. Question 2
    Hard
    After the procedure, the patient is given 100% oxygen for several minutes to:
  3. Question 3
    Moderate
    In minimal sedation, this patient should:
  4. Question 4
    Moderate
    Because sedation is a continuum, the clinician must still:
  5. Question 5
    Moderate
    A practical advantage of nitrous oxide for this anxious patient is that it:

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Keep studying
Local Anesthesia & Sedation core recall

Refresh the anatomy facts these cases depend on: nerve numbers, foramina, functions, and lesion findings.

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