Related Experiment Video

Updated: Jul 16, 2026

Electrophysiological Methods to Assess Peripheral Pain Block in an Anesthetized Rat
08:05

Electrophysiological Methods to Assess Peripheral Pain Block in an Anesthetized Rat

Published on: November 21, 2025

The effects of clonidine on postoperative analgesia after peripheral nerve blockade in children

Giovanni Cucchiaro1, Arjunan Ganesh

  • 1Department of Anesthesiology and Critical Care Medicine, The Children's Hospital of Philadelphia and the University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA. cucchiaro@email.chop.edu

Anesthesia and Analgesia
|February 22, 2007
PubMed

Insights

Adding clonidine to local anesthetics significantly extends sensory and motor block duration in pediatric peripheral nerve blocks. This enhances postoperative analgesia but may increase the incidence of prolonged numbness.

Area of Science:

  • Anesthesiology
  • Pediatric Regional Anesthesia

Background:

  • The impact of clonidine on the duration of sensory blockade following peripheral nerve blocks remains debated.
  • This study aimed to clarify clonidine's effects on sensory and motor blockade and analgesia in pediatric patients.

Purpose of the Study:

  • To evaluate the efficacy of clonidine as an adjunct to local anesthetics in pediatric peripheral nerve blocks.
  • To determine the influence of clonidine on the duration of sensory and motor blockade and postoperative analgesia.

Main Methods:

  • A retrospective review of a regional anesthesia database at The Children's Hospital of Philadelphia (October 2002 - December 2005).
  • Analysis of data from children undergoing various peripheral nerve blocks (infraclavicular, lumbar plexus, femoral, fascia iliaca, sciatic) for postoperative analgesia.
  • Prospective follow-up of patients post-nerve block.

Main Results:

  • Patients receiving local anesthetic plus clonidine (LAC) showed significantly longer sensory block duration (17.2 ± 5 h) compared to local anesthetic alone (LA) (13.2 ± 5 h).
  • Motor block duration was also significantly longer in the LAC group (9.6 ± 5 h) versus the LA group (4.3 ± 4 h).
  • The observed increases in block duration were independent of the specific nerve block, local anesthetic, or surgical procedure.

Conclusions:

  • Clonidine addition to bupivacaine or ropivacaine effectively extends sensory block duration in pediatric peripheral nerve blocks.
  • The use of clonidine also increases the incidence and duration of motor blockade.
  • While generally safe, prolonged numbness was observed in a small percentage of patients.
Abstract

Related Concept Videos

Parenteral Anesthetics: Overview01:24

Parenteral Anesthetics: Overview

Intravenous anesthetics are drugs administered parenterally to induce anesthesia or sedation. Propofol is a widely used agent formulated as a 1% emulsion in soybean oil, glycerol, and egg phosphatide. It induces rapid anesthesia primarily due to its rapid distribution from the bloodstream to target tissues and is metabolized in the liver. However, it can cause significant pain on injection and hypertriglyceridemia. Fospropofol, a water-based prodrug of propofol, lacks these adverse effects.
Local Anesthetics: Differential Sensitivity of Nerve Fibers01:24

Local Anesthetics: Differential Sensitivity of Nerve Fibers

Local anesthetics (LAs) block the sodium channels of nerve trunks, sensory nerve endings, and neuromuscular junctions. Although LAs can block all kinds of nerves, the sensitivity of nerve fibers differs according to nerve types and structures. LAs are known to block myelinated fibers faster than unmyelinated ones. Also, they block pain or sensory neurons at low concentrations without affecting the motor neurons involved in muscle contractions. This helps relieve labor pain without affecting the...
Local Anesthetics: Clinical Application as Epidural Anesthesia01:29

Local Anesthetics: Clinical Application as Epidural Anesthesia

Epidural anesthetics are administered in the fat-filled epidural space, the outermost part of the spinal canal. This technique is commonly employed for pain management and anesthesia during lower abdomen and pelvis surgeries or labor and delivery.
Since epidural anesthetics can be infused through an epidural catheter, all types of drugs, including short-acting ones, can be administered. Chloroprocaine and lidocaine are examples of short and long-duration anesthetics, respectively. Bupivacaine...
Local Anesthetics: Pharmacokinetics01:13

Local Anesthetics: Pharmacokinetics

The potency and duration of action of local anesthetics (LAs) are determined by their pharmacokinetics. Pharmacokinetics describes how LAs are absorbed, distributed, metabolized, and eliminated from the body. When administered to the vascular tissues, LAs are quickly absorbed and enter the systemic circulation, reducing their localized effects. Adding vasoconstrictors such as epinephrine to LAs reduces their absorption into the systemic circulation, making them clinically effective. The...
General Anesthesia: Overview01:24

General Anesthesia: Overview

Anesthesia is a medical procedure that uses drugs for CNS suppression to enable painless surgeries and procedures. The selection of anesthetics is influenced by their pharmacokinetic properties, side effects, and patient characteristics. Various types of anesthesia include general, local, regional, spinal, and inhalational.
General anesthesia induces unconsciousness in the whole body, while the others target specific areas or sensations. It is administered to minimize adverse effects, maintain...
Local Anesthetics: Clinical Application as Intravenous Regional Anesthesia01:16

Local Anesthetics: Clinical Application as Intravenous Regional Anesthesia

Intravenous regional anesthesia or the Bier block technique is used to anesthetize a specific limb or extremity. It uses exsanguinated or blood-drained vessels to transport local anesthetics or LAs to the peripheral nerve trunks. Lidocaine without vasoconstrictors like epinephrine is most commonly used for this technique. Other drugs used are prilocaine, ropivacaine, and chloroprocaine. Bupivacaine is not recommended for this technique due to its high cardiac toxicity.
One of the advantages of...