A. Cervin et S. Lindberg, CHANGES IN MUCOCILIARY ACTIVITY MAY BE USED TO INVESTIGATE THE AIRWAY-IRRITATING POTENCY OF VOLATILE ANESTHETICS, British Journal of Anaesthesia, 80(4), 1998, pp. 475-480
We have examined the short-term effects of th ree volatile anaesthetic
s, halothane, isoflurane and desflurane, on mucociliary activity in th
e rabbit maxillary sinus in vivo. Mucociliary activity was recorded ph
otoelectrically and the signal processed by fast Fourier transformatio
n. Administration of 1.0 MAC of halothane, isoflurane or desflurane ca
used a temporary increase in mucociliary activity, with mean peak resp
onses of 47.8 (SEM 13.0)%, 44.0 (9.6)% and 45.1 (23.7)% (n=6), respect
ively. The response to all three compounds was biphasic; an initial pe
ak was observed within 2 min and a second peak at 3-8 min. The second
response was not significant for halothane. In contrast, desflurane pr
oduced a significant second peak while the first was small and failed
to reach significance. Halothane displayed an initial peak within 2 mi
n which was blocked by atropine but not by the neurokinin 1 (NK1) rece
ptor antagonist CP-99. The second peak at 3-5 min was less pronounced
for halothane than for isoflurane or desflurane. The second peak was n
ot affected by atropine pretreatment, but was blocked by pretreatment
with CP-99. A combination of atropine and CP-99 pretreatment abolished
the mucociliary response to halothane. Atropine pretreatment did not
affect, whereas CP-99 significantly reduced, the response to desfluran
e. We conclude that the NK1-mediated response was most pronounced for
desflurane which is considered the most airway irritating compound of
the three. It is likely that the size of the NK1-mediated response ref
lects the airway-irritating properties of the volatile anaesthetic use
d.