Pre-operative prediction of 'dry taps'.
OBJECTIVE
The treatment of children with 'glue ear' often presents surgeons with the question of whether or not to insert a grommet when myringotomy reveals no fluid in the middle ear. We present a study designed to assess which factors contribute to the presence of a 'dry tap'.


METHODS
We prospectively gathered data from a cohort of 280 children (504 myringotomies). The cohort included two subgroups, one received halothane and nitrous oxide anaesthesia, and the other received enflurane anaesthesia.


METHODS
The ENT department of a district general hospital.


METHODS
Children (aged less than 17 years) requiring myringotomy.


METHODS
The presence of a 'glue' or dry tap at myringotomy was documented. We also recorded data on the following: pre- and post-induction tympanometry; age; season; anaesthetic type; and the delay from listing to actual operation.


RESULTS
A non type B pre-induction tympanogram and delay to operation were strong indications of finding a dry tap at surgery.


CONCLUSIONS
In our study population, the proportion of dry taps at myringotomy was 18 per cent. The presence of a dry tap was rarely due to the induction of anaesthesia. Multivariate analysis revealed that the combination of factors most likely to predict a dry tap were non type B tympanogram and delay to operation.
Henney
S
S
Department of Otolaryngology Head & Neck Surgery, Cumberland Infirmary, Carlisle, UK. scott.henney@doctors.org.uk
Counter
P
P
Mirza
S
S
Gedling
P
P
Watson
C
C
D000293:Adolescent; D018685:Anesthetics, Inhalation / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D004432:Ear, Middle / Q000601:surgery*; D004737:Enflurane / Q000009:adverse effects; D006221:Halothane / Q000009:adverse effects; D006801:Humans; D008876:Middle Ear Ventilation / Q000379:methods*; D015999:Multivariate Analysis; D009225:Myringoplasty / Q000379:methods*; D009609:Nitrous Oxide / Q000009:adverse effects; D010034:Otitis Media with Effusion / Q000175:diagnosis* / Q000601:surgery; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012075:Remission, Spontaneous; D014432:Tympanic Membrane / Q000601:surgery*
D018685:Anesthetics, Inhalation; D004737:Enflurane; D009609:Nitrous Oxide; D006221:Halothane