FACILITATION OF FIBEROPTIC OROTRACHEAL INTUBATION WITH A FLEXIBLE TRACHEAL TUBE

Advancement of a tracheal tube (TT) over a flexible fiberoptic broncho scope (FOB) is often impeded by obstruction at the arytenoid cartilage or epiglottis. We tested the hypothesis that the use of a flexible, s piral-wound TT, rather than the standard, preformed TT would facilitat e tube passage into the trachea over the FOB. Forty patients scheduled to undergo general anesthesia with tracheal intubation were randomize d to two groups. Then the trachea was intubated with a FOB, followed b y passage of either a standard, preformed TT or a flexible, spiral-wou nd TT over the FOB. Ease of TT advancement over the FOB into the trach ea was graded on a 1 (easy) to 3 (difficult) scale, and differences be tween the two groups were compared with chi2 analysis. The overall sco res were compared with Wilcoxon's ranked sum test. Statistical signifi cance was defined as P < 0.05. In patients randomized to the regular T T, only 35% (7/20) of first attempts to advance the TT over the FOB we re successful. In the patients randomized to the spiral-wound TT, 95% (19/20) of first attempts were successful (P < 0.0001). Of the 13 regu lar TTs that were not successfully advanced on the first attempt, seve n could not be passed after the second or third attempt (necessitating the use of the cross-over spiral-wound TT). In the only instance in w hich a spiral-wound tube was not successfully passed into the trachea on the first attempt, passage also was not achieved after the second o r third attempt. The median scores for ease of tracheal passage (and 2 5-75 percentiles) were 2 (1-3) when the initial attempt was with the r egular TT and 1 (1-1) when the initial attempt was with the spiral-wou nd TT (P < 0.0002). The authors conclude that a spiral-wound, wire-rei nforced TT is less likely to encounter obstruction on glottic structur es than its preformed counterpart. We attribute this difference to the greater side-to-side flexibility of the spiral-wound tube when compar ed with the preformed tube. This increased flexibility allows the spir al-wound tube to bend more easily and thus conform to the acute angle which the stenting FOB may develop in the posterior pharynx. An additi onal advantage may be conferred by the more obtuse angle of the wire-r einforced TT's distal end, making it less likely to impinge on pharyng eal soft tissue during its advancement into the trachea.