Anesthesiology. 2001 Nov;95(5):1120-4.
Anesthesiology. 2002 Sep;97(3):757; author reply 758.
Intracuff pressure and tracheal morbidity: influence of filling with saline
during nitrous oxide anesthesia.
Combes X, Schauvliege F, Peyrouset O, Motamed C, Kirov K, Dhonneur G,
Department of Anesthesia, Hopital Henri Mondor, Creteil, france.
BACKGROUND: Diffusion of nitrous oxide into the cuff of the endotracheal tube
results in an increase in cuff pressure. Excessive endotracheal tube cuff
pressure may impair tracheal mucosal perfusion and cause tracheal damage and
sore throat. Filling the cuff of the endotracheal tube with saline instead of
air prevents the increase in cuff pressure due to nitrous oxide diffusion. This
method was used to test whether tracheal morbidity is related to excess in
tracheal cuff pressure during balanced anesthesia. METHODS: Fifty patients with
American Society of Anesthesiologists physical status I or II were randomly
allocated to two groups with endotracheal tube cuffs initially inflated to 20-30
cm H(2)O with either air (group A) or saline (group S). Anesthesia was
maintained with isoflurane and nitrous oxide. At the time of extubation, a
fiberoptic examination of the trachea was performed by an independent observer,
and abnormalities of tracheal mucosa at the level of the cuff contact area were
scored. Patients assessed their symptoms (sore throat, dysphagia, and
hoarseness) at the time of discharge from the postanesthesia care unit and 24 h
after extubation on a 101-point numerical rating scale. RESULTS: Cuff pressure
increased gradually during anesthesia in group A but remained stable in group S.
The incidence of sore throat was greater in group A than in group S in the
postanesthesia care unit (76 vs. 20%) and 24 h after extubation (42 vs. 12%; P <
0.05). Tracheal lesions at time of extubation were seen in all patients of group
A and in eight patients (32%) of group S (P < 0.05). CONCLUSION: Excess in
endotracheal tube cuff pressure during balanced anesthesia due to nitrous oxide
diffusion into this closed gas space causes sore throat that is related to
tracheal mucosal erosion.
Anesth Analg. 1992 Jun;74(6):897-900.
Sore throat after endotracheal intubation.
Mandoe H, Nikolajsen L, Lintrup U, Jepsen D, Molgaard J.
Department of Anesthesia, Central Hospital, Herning, Denmark.
Nitrous oxide can diffuse into the cuff of an endotracheal tube during tracheal
intubation, and the cuff pressure against the tracheal wall may cause mucosal
damage. An endotracheal tube has been developed (Brandt Anesthesia Tube) that
effectively limits nitrous oxide-related intracuff pressure increases. We
determined whether the incidence of postoperative sore throat could be reduced
by using this tube. Forty-eight female patients, 18-50 yr of age, were included
in the study. Endotracheal intubation was performed with either a Brandt
Anesthesia Tube or a Mallinckrodt endotracheal tube. All patients were
interviewed postoperatively after 20-30 h by individuals who did not know which
tube was used. In the Mallinckrodt group, 12 of 20 patients had a sore throat
and 10 patients had intracuff pressures greater than 25 mm Hg. Only 3 of 20
patients in the Brandt group had a sore throat. We found that the incidence of
sore throats after intubation could be significantly reduced by using the Brandt
Anesthesia Tube (P less than 0.005).