Sensitivity of upper airway reflexes in cigarette smokers: effect of abstinence

Abstract

In two studies we have compared the upper airway reflex sensitivity (UARS) of chronic cigarette smokers with that of non-smokers and also the effect of different periods of abstinence on UARS in the smoking groups. UARS was measured by recording the threshold concentration of dilute ammonia vapour required to stimulate reflex glottic closure. The first study compared UARS in 20 non-smokers with 20 smokers, followed by another measurement in the smoking group after 24 h of abstinence. In study two, we measured UARS repeatedly over a period of 3-4 weeks in 16 smokers, half of whom had stopped smoking on day 0. Chronic cigarette smokers were found to have significantly greater UARS compared with non-smokers; the sensitivity was unaltered after 24 h of abstinence but was found to reduce over several days, the change commencing between 24 and 48 h, with most achieving a consistent change within 10 days.

Minimum alveolar sevoflurane concentrations required for insertion of the cuffed oropharyngeal airway and the laryngeal mask airway: a comparative study

“…Age-related changes in upper airway sensitivity, as well as a high proportion of smokers among our patients, do not seem to play a role in possibly overestimating the MAC LMA value in the elderly patients, since the upper airway sensitivity decreases linearly with advancing age and chronic smokers exhibit depressed upper airway sensitivity to chemical stimuli [15,16]. Whether the sensitivity of pharyngeal and supraglottic mucosa to mechanical stimulation is altered by these factors remains to be determined.…”

Effect of smoking on induction of anaesthesia with sevoflurane

“…The concern that this method may cause problems in patients with increased airway sensitivity led us to study inhalational induction in smokers. Smokers have an increased sensitivity of upper airway reflexes [11] and are more likely than non-smokers to suffer from laryngospasm, coughing, breath-holding and desaturation [12,13].…”

“…Isolated case reports of the use of sevoflurane induction in patients with difficult or potentially irritable airways have been published [7±9]; however, there have been no prospective studies on patients with potential irritable airways, an omission noted by Smith et al [10]. Smokers have an increased sensitivity of upper airway reflexes [11] and are more likely to suffer from adverse events such as coughing, breath holding and laryngospasm during induction of anaesthesia [12,13]. In addition, smokers are more likely to suffer cardiovascular complications during anaesthesia [14].…”

Implicações anestésicas do tabagismo

“…Em estudo avaliando a sensibilidade reflexa das vias aéreas a estímulos químicos e mecânicos, Erskine e col. observaram seu aumento em pacientes fumantes crônicos, que determinaria maior freqüência de episódios de laringoespasmo e obstrução das vias aéreas, com redução na saturação de oxigênio 27 . Aabstinência de 24 horas do uso de tabaco sobre o grupo de fumantes não produziu alteração significativa, porém houve redução progressiva da sensibilidade reflexa após 24-48 horas, observando-se mudanças consistentes após 10 dias.…”