title: Determining the technical and clinical factors associated with pain for children undergoing botulinum toxin injections under nitrous oxide and anesthetic cream.
abstract: OBJECTIVE
  To determine technical and clinical factors associated with pain when using an analgesic protocol with 50% nitrous oxide/oxygen and anesthetic cream (lidocaine and prilocaine, Emla(®)) for children with cerebral palsy undergoing botulinum toxin injections.
  
  
  METHODS
  Monocentric prospective study including 50 children newly injected with a mean age of 6.6 years (± 4.32, range 1-18) and 199 injected muscles. Pain was evaluated using the Children's Hospital of Eastern Ontario Pain Scale (CHEOPS). The following variables were noted: gender, age, weight, Gross Motor Function Classification System, type of cerebral palsy (hemiplegic, diplegic, tetraplegic), muscles injected and severe cognitive impairment. The procedure was broken down into three phases for the purpose of pain evaluation: puncture, muscle localization using electrostimulation and injection of botulinum toxin.
  
  
  RESULTS
  The mean CHEOPS score was 8.16 (± 3.5) and 38% of scores were above the therapeutic threshold of 9. The injection phase was significantly more painful (6.77 ± 3.30) than the puncture (4.88 ± 2.03) and localization (5.46 ± 2.68) phases. The adductor muscles were less painful than other muscles. Children with more severe cognitive impairment seemed to perceive higher levels of pain than the others. Other clinical factors were not associated with pain score.
  
  
  CONCLUSIONS
  Clinical characteristics seem not strongly correlated to the success or failure of the 50% nitrous oxide/oxygen-Emla(®) protocol and this pain treatment protocol does not prevent equally all phases of botulinum toxin injections. Future research on the products and its dilution might help to reduce pain level.
authors.affiliation: Service de Médecine Physique et de Réadaptation, Centre Hospitalo-Universitaire Morvan, 5 avenue Foch, 29200 Brest, France. sylvain.brochard@chu-brest.fr
authors.forename: Sylvain
authors.initials: S
authors.lastname: Brochard
authors.forename: Virginia
authors.initials: V
authors.lastname: Blajan
authors.forename: Mathieu
authors.initials: M
authors.lastname: Lempereur
authors.forename: Ronan
authors.initials: R
authors.lastname: Garlantezec
authors.forename: Laetitia
authors.initials: L
authors.lastname: Houx
authors.forename: Philippe
authors.initials: P
authors.lastname: Le Moine
authors.forename: Sylviane
authors.initials: S
authors.lastname: Peudenier
authors.forename: Jérémie
authors.initials: J
authors.lastname: Lefranc
authors.forename: Olivier
authors.initials: O
authors.lastname: Rémy-Néris
mesh_terms: D000287:Administration, Topical; D000293:Adolescent; D000779:Anesthetics, Local / Q000008:administration & dosage; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000009:adverse effects*; D002547:Cerebral Palsy / Q000188:drug therapy*; D002648:Child; D002675:Child, Preschool; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007223:Infant; D007273:Injections, Intramuscular / Q000009:adverse effects / Q000379:methods; D008012:Lidocaine / Q000008:administration & dosage*; D008297:Male; D009465:Neuromuscular Agents / Q000008:administration & dosage / Q000009:adverse effects; D009609:Nitrous Oxide / Q000008:administration & dosage*; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010264:Paraplegia / Q000188:drug therapy*; D011318:Prilocaine / Q000008:administration & dosage; D011446:Prospective Studies
chemical_list: D000779:Anesthetics, Local; D009465:Neuromuscular Agents; D011318:Prilocaine; D008012:Lidocaine; D019274:Botulinum Toxins, Type A; D009609:Nitrous Oxide