Local Anesthetics Overview and Applications

Which local anesthetic can be administered via the intravenous route?

In which of the following nerve blocks should the administration of adrenaline be avoided to prevent potential complications?

Which of the following local anesthetics is linked by an ester bond?

What is the typical composition used for achieving analgesia without complete anesthesia during labor?

Below which intervertebral space can the spinal needle be inserted for a patient undergoing hemorrhoidectomy under spinal anesthesia?

Which anesthetic drug overdose can cause symptoms of extreme drowsiness, slurred speech, pallor, tachycardia, tachypnea, and jerky limb movements?

What is the presumptive diagnosis when an 18-year-old woman in active labor complains of circumoral numbness after receiving epidural lidocaine?

What is the correct order of absorption for local anesthetics from fastest to slowest?

Which statement about EMLA cream is true?

What is the primary rationale for adding dextrose to spinal anesthesia?

Local Anesthetics Overview

Prilocaine and lidocaine are commonly used local anesthetics; lidocaine can be administered intravenously.
Bupivacaine and ropivacaine are used for nerve blocks but are not suitable for intravenous administration.

Adrenaline Use in Nerve Blocks

Adrenaline (epinephrine) enhances the effects of local anesthetics.
It should be avoided in penile nerve blocks to prevent complications such as ischaemia.

Chemical Structure of Local Anesthetics

Cocaine is linked by an ester bond, unlike lidocaine, bupivacaine, and dibucaine, which are amides.

Analgesia during Labor

Bupivacaine 0.125% combined with fentanyl is commonly used for analgesia without full anesthesia during labor.

Spinal Anesthesia Procedure

For spinal anesthesia, the needle can be inserted below the L3–L4 intervertebral space, considering the patient's medical history.

Local Anesthetic Overdose Symptoms

Symptoms of overdose from anesthetics like articaine and mepivacaine include extreme drowsiness and pallor.

Epidural Injection Reactions

Circumoral numbness and apprehension after lidocaine epidural injection may indicate systemic toxicity rather than an allergy.

Absorption Rates of Local Anesthetics

Route of absorption from fastest to slowest: endotracheal, intercostal block, lumbar epidural, subcutaneous.

EMLA Cream Composition

EMLA cream is a eutectic mixture of local anesthetics with a 1:1 ratio of lidocaine to prilocaine.

Dextrose in Spinal Anesthesia

Dextrose is added to spinal anesthesia to create hyperbaric solutions, enhancing effectiveness and duration.

Local Anesthesia for Percutaneous Coronary Intervention

For patients with STEMI, local anesthesia is used for procedures like PCI, allowing immediate coronary angiography without general anesthesia.

General Anesthesia Summary

General anesthesia provides amnesia, analgesia, and sedation, creating a controlled reversible state of unconsciousness for surgeries.

Epidural Anesthesia Context

Epidural anesthesia is a regional technique that blocks pain in specific body areas and can be combined with general anesthesia for enhanced analgesic effects.

This quiz covers the essential aspects of local anesthetics, including commonly used types like lidocaine and bupivacaine, their mechanisms, and applications in medical procedures such as spinal anesthesia and labor analgesia. Additionally, it addresses the chemical structure and overdose symptoms associated with these anesthetics.