ANESTHESIA

What is anesthesia?

The temporary loss of feeling or sensation.

What are anesthetics?

Drugs that produce a temporary loss of feeling.

What is the main purpose of a topical anesthetic?

To numb nerve endings at the injection site before an injection.

What are the forms of topical anesthetics?

Ointments, liquids/rinses, sprays, and patches.

What is the active ingredient in topical anesthetic ointment?

Benzocaine.

What concentration is benzocaine in topical anesthetic ointment?

20%.

What are topical anesthetic sprays commonly used for?

To control an overactive gag reflex.

What is a local anesthetic?

An injectable form of anesthetic.

What are the two chemical forms of local anesthetics?

Amides and esters.

How are amide anesthetics metabolized?

By the liver.

How are ester anesthetics metabolized?

Within the blood plasma.

Why is sodium chloride added to local anesthetics?

To make the solution isotonic with body tissues.

What is the main purpose of a vasoconstrictor in a local anesthetic?

To decrease anesthetic uptake by the bloodstream.

What is the main effect of a vasoconstrictor?

It constricts blood vessels at the injection site.

What are common vasoconstrictors?

Epinephrine, levonordefrin, and Neo-Cobefrin.

Which vasoconstrictor ratio lasts the longest?

1:20,000.

Which vasoconstrictor ratio lasts the shortest?

1:200,000.

What does a “No Epi” warning mean?

The patient should not receive anesthetic containing a vasoconstrictor.

What is induction?

The time from injection until anesthesia occurs.

What is duration?

The length of time the anesthesia lasts.

What is the duration of short-acting anesthesia?

60–180 minutes.

What is the duration of intermediate-acting anesthesia?

120–240 minutes.

What is the duration of long-acting anesthesia?

240–540 minutes.

What is local infiltration?

Anesthetic injected near a tooth's apex for single-tooth anesthesia.

What is a field block?

Anesthetic injected near a larger terminal nerve branch to numb 2–3 teeth.

What is a nerve block?

Anesthetic injected near a main nerve trunk to numb an entire quadrant.

What does a greater palatine nerve block numb?

The posterior portion of the hard palate.

What does a nasopalatine nerve block numb?

The anterior portion of the hard palate.

What does a mandibular/inferior alveolar nerve block numb?

An entire left or right mandibular quadrant.

What does a buccal nerve block numb?

Soft tissue buccal to the mandibular molars.

What does an incisive nerve block numb?

The anterior teeth on the left or right side.

What is paresthesia?

Numbness that continues after the anesthetic has worn off.

Where are contaminated anesthetic needles disposed of?

In a red sharps container.

What needle length is used for maxillary infiltration?

Short (1 inch).

What needle length is used for mandibular nerve blocks?

Long (1 5/8 inches).

What needle length is used for periodontal ligament injections?

Extra short (1/4 inch).

What is “white noise” in anesthesia?

An alternate stimulus that confuses the nerve.

What is the most common inhalation sedation used in dentistry?

Nitrous oxide/oxygen (N₂O/O₂).

What is the chemical name of N₂O?

Dinitrogen monoxide.

What stage of anesthesia does nitrous oxide produce?

Stage I anesthesia/analgesia.

Why is N₂O mixed with oxygen?

To prevent the patient from suffocating.

What color is a nitrous oxide tank?

Blue.

What color is an oxygen tank?

Green.

What is the purpose of the scavenger system?

To reduce nitrous oxide released into the operatory.

What does nitrous oxide administration begin with?

Pure oxygen.

What are antianxiety drugs also called?

Anxiolytics.

What are benzodiazepines?

Antianxiety drugs.

What is an example of a benzodiazepine?

Diazepam (Valium).

What is Stage I anesthesia?

Analgesia; the patient is conscious, relaxed, and can follow directions.

What is Stage II anesthesia?

Excitement; the patient may become less aware, nauseous, or unmanageable.

What is Stage III anesthesia?

General anesthesia; the patient is unconscious and feels no pain.

What is required for Stage III general anesthesia?

An anesthesiologist and a hospital setting.

What occurs during Stage IV anesthesia?

Respiratory and cardiac failure can occur.