title: Topical ethyl chloride fine spray. Does it have any antimicrobial activity?
abstract: OBJECTIVE
  The aim of this study was to assess whether ethyl chloride fine spray (Cryogesic) has antimicrobial activity.
  
  
  METHODS
  Blood agar plates supplemented with 5% horse blood were inoculated with five different organisms, coagulase-negative staphylococci (CNS), methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Streptococcus pyogenes and Enterococcus faecalis. The plates were assessed for growth inhibition at 24 and 48 h by the microbiologist and compared with the non-sprayed control plates.
  
  
  RESULTS
  The model showed a highly significant (p<0.0001) reduction in bacterial count for the plates treated with fine ethyl chloride spray. The estimate of the percentage of bacteria remaining after spraying with ethyl chloride was 42.7%, with a 95% confidence interval of 35.9-50.9%. There was no evidence that the effect of ethyl chloride fine spray was different for the different organisms (p=0.49).
  
  
  CONCLUSIONS
  The use of ethyl chloride shows bacterial count reduction but the clinical implication of this needs to be determined. The authors postulate that any statistically significant reduction can only be helpful in reducing the infection rates. This coupled with the already proven local anaesthetic effects of ethyl chloride will make it an important tool for procedures like arthrocentesis and venepunctures.
authors.affiliation: Department of Clinical Radiology, Southmead Hospital, Westbury on Trym, Bristol, UK. kburney@doctors.org.uk
authors.forename: K
authors.initials: K
authors.lastname: Burney
authors.forename: K
authors.initials: K
authors.lastname: Bowker
authors.forename: R
authors.initials: R
authors.lastname: Reynolds
authors.forename: M
authors.initials: M
authors.lastname: Bradley
mesh_terms: D000287:Administration, Topical; D000336:Aerosols; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D015169:Colony Count, Microbial; D013293:Enterococcus faecalis / Q000187:drug effects; D005018:Ethyl Chloride / Q000008:administration & dosage*; D006095:Gram-Positive Cocci / Q000187:drug effects*; D006801:Humans; D016106:Methicillin Resistance; D012881:Skin Temperature; D013210:Staphylococcus / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects; D013297:Streptococcus pyogenes / Q000187:drug effects
chemical_list: D000336:Aerosols; D000900:Anti-Bacterial Agents; D005018:Ethyl Chloride