The effect of different inflating volume on the measurement accuracy of the modified cuff pressure measurement method

To evaluate the effect of different inflation volume on the measurement accuracy of the modified cuff pressure measurement method in different shapes of cuffs, so as to provide reference for the correct monitoring of cuff pressure in clinic. In vitro study: The traditional cuff pressure measurement method (the cuff pressure gauge before measurement shows 0 cm H₂O) and the modified cuff pressure measurement method (the cuff pressure before measurement shows 25 cm H₂O, 28 cm H₂O, 30 cm H₂O or 32 cm H₂O) were used to measure cylindrical and tapered cuffs, and the effect of different inflation volume on cuff pressure was analyzed statistically. Clinical study: patients with the artificial airway established by orotracheal intubation or tracheotomy in Neuro-ICU were prospectively selected as subjects, and the measurement procedure was the same as in vitro study. In vitro study showed that the pressure loss values of cylindrical cuff and tapered cuff using the traditional cuff pressure measurement method were (3.75 ± 0.31) cm H₂O and (4.92 ± 0.44) cm H₂O, respectively, and clinical study showed that the pressure loss values were (5.07 ± 0.83) cm H₂O and (5.17 ± 0.93) cm H₂O, respectively. The actual measured values measured by the traditional cuff pressure measurement method of the two cuff shapes were compared with the corrected target value of 28 cm H₂O, and the differences were statistically significant (P < 0.000). Both in vitro and clinical study had shown that all differences between the actual measured value and the corrected target value using the modified cuff pressure measurement method (measured with 25 cm H₂O, 30 cm H₂O, 32 cm H₂O) were statistically significant (P < 0.000), and the range of overall differences was (0-1.23 ± 0.25) cm H₂O. In vitro study had shown that the pressure variation coefficient (CV) of the tapered cuff was greater than that of the cylindrical cuff, and the difference was statistically significant (3.08 ± 0.25 VS 2.41 ± 0.21, P < 0.000). The traditional cuff pressure measurement method can directly lead to the cuff pressure drop, which is easy to cause the leakage of secretions on the cuffs and the misjudgment of the cuff pressure by medical personnel. However, the modified cuff pressure measurement method can effectively reduce cuff pressure loss, and taking the actual cuff pressure value as the inflation volume is the highest measurement accuracy.The tapered cuff is more susceptible to air volume, so it is necessary to pay attention to its measurement and correction in clinical practice.