Nitrous oxide for applying local anesthesia in nasal operations: a randomized placebo-controlled single-blinded study.
CONCLUSIONS
In our study setting nitrous oxide (N(2)O) did not show any clinical benefit in discomfort experienced when applying local anesthesia for nasal operations. Further studies with longer inhalation times are needed to elucidate the role of N(2)O in application of local anesthesia in nasal surgery.


OBJECTIVE
N(2)O inhalation reduces the discomfort experienced in various medical procedures. The objective of this study was to assess the suitability of N(2)O inhalation before application of local anesthesia for nasal procedures in outpatient surgery.


METHODS
This was a prospective, randomized, single-blinded, placebo-controlled study at the Helsinki University Central Hospital, Finland. Ninety patients were randomly divided into three groups. Group A inhaled 10 breaths of 50% N(2)O/50% O(2) through a nasal mask with a Porter 2000 MXR scavenging system before application of local nasal anesthesia, group B inhaled room air through the same mask and group C received only local anesthesia. A visual analog scale was used to assess pain, nausea, and discomfort related to the application of nasal anesthesia.


RESULTS
The N(2)O inhalation was easy to perform and well tolerated. The N(2)O inhalation before applying local anesthesia for nasal operations did not show any significant additional benefit in reducing pain or discomfort.
Department of Otorhinolaryngology, Helsinki University Central Hospital, Helsinki, Finland.
Marit
M
Starck
Pekka
P
Tarkkila
Antti A
AA
Mäkitie
Jukka S
JS
Ylikoski
Leif J J
LJ
Bäck
D000293:Adolescent; D000328:Adult; D000368:Aged; D000772:Anesthesia, Local / Q000295:instrumentation*; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009609:Nitrous Oxide / Q000008:administration & dosage*; D009668:Nose Diseases / Q000601:surgery*; D013517:Otorhinolaryngologic Surgical Procedures / Q000379:methods*; D010147:Pain Measurement; D011446:Prospective Studies; D016037:Single-Blind Method
D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide