Examination of the frequency of upward and downward fluctuations in the pressure obtained from the cuff pressure-time curve by continuous measurement of endotracheal tube cuff pressure during thyroid surgery: a case series

BACKGROUND: Few studies examined time-to-time changes of cuff pressure of an endotracheal tube during surgery. We retrospectively analyzed the changes of cuff pressure during thyroid surgery and examined its relationships with postoperative airway complications. CASE PRESENTATION: Cuff pressure was initially adjusted at 26 cmH(2)O and continuously measured in 61 patients. The cuff pressure-time curve dynamically fluctuated, and exceeded 30 cmH(2)O in all patients, whereas decreased to ≤ 20 cmH(2)0 in 42 (69%) patients. Ratio of the period with such an increase and decrease of cuff pressure to the total duration of surgery were 40% (28–66%) and 9% (0–21%), respectively (median, interquartile range). No patients showed symptoms of airway stenosis requiring treatment except one who developed recurrent laryngeal nerve palsy. No patients had lower respiratory tract infection. CONCLUSIONS: Cuff pressure dynamically fluctuated during thyroid surgery. Preventing an increase as well as decrease of cuff pressure is required.