title: Assessment of maxillary and infraorbital nerve blockade for rhinoscopy in sevoflurane anesthetized dogs.
abstract: OBJECTIVE
  To investigate the efficacy of maxillary and infraorbital nerve blocks for prevention of cardiovascular and qualitative responses to rhinoscopy, as well as response to skin clamping after assigned nerve block placement.
  
  
  METHODS
  Randomized, blinded, placebo-controlled cross-over experimental study.
  
  
  METHODS
  Eight random-source mixed breed dogs > 1 year old and weighing between 13 and 22 kg.
  
  
  METHODS
  Within three anesthetic episodes, separated by at least 3 days, dogs were assigned to receive either 1 mL lidocaine 2% maxillary nerve block (ML); 0.5 mL lidocaine 2% infraorbital nerve block (IOL); or equal amounts of saline for maxillary or infraorbital nerve block combined as control treatment (S). Monitoring included temperature, respiratory rate, end-tidal CO2 , ECG, heart rate (HR), systolic, diastolic and mean arterial pressure (SAP, DAP, MAP). Posterior (pR) and anterior rhinoscopies (aR) were performed and scored. Differences from baseline for outcome parameters HR, SAP, DAP, MAP were analyzed using repeated-measures anova, and results reported as mean ± SD. Binary scores for rhinoscopy were analyzed using logistic regression, and odds ratio was reported.
  
  
  RESULTS
  Changes from baseline for HR and SAP were significant for all treatments, besides ML for pR. Difference in changes from baseline among treatments was statistically significant for HR during pR with ML < S, and for SAP, DAP and MAP in right and left aR with ML < S and IOL > ML, except for DAP in left aR with only IOL > ML. Analysis of the binary score showed that the probability of a response for S and IOL treatments was nearly triple that of the ML treatment. None of the dogs, regardless of the treatments applied, responded to skin clamping.
  
  
  CONCLUSIONS
  Cardiovascular parameters do not seem to reflect the occurrence of adverse reactions during rhinoscopy. The maxillary nerve block is superior to the infraorbital nerve block, as applied in this study, in preventing adverse reactions during posterior rhinoscopy.
authors.affiliation: Animal Health Trust, Anaesthesia Department, Landwades Park, Kentford, Newmarket, UK. jeacremer@gmx.de
authors.forename: Jeannette
authors.initials: J
authors.lastname: Cremer
authors.forename: Steffen O
authors.initials: SO
authors.lastname: Sum
authors.forename: Christina
authors.initials: C
authors.lastname: Braun
authors.forename: Juliana
authors.initials: J
authors.lastname: Figueiredo
authors.forename: Carolina
authors.initials: C
authors.lastname: Rodriguez-Guarin
mesh_terms: D000818:Animals; D001794:Blood Pressure; D018592:Cross-Over Studies; D004285:Dogs; D004724:Endoscopy / Q000662:veterinary*; D006339:Heart Rate; D008738:Methyl Ethers / Q000494:pharmacology*; D009407:Nerve Block / Q000662:veterinary*; D010147:Pain Measurement; D000077149:Sevoflurane
chemical_list: D008738:Methyl Ethers; D000077149:Sevoflurane