Vasudevan Arumugam, Srinivasan Suganya, Vinayagam Stalin, Ramkumar Govindarajalou, Senthilnathan Muthapillai
Department of Anesthesiology and Critical Care, Jawaharlal Institute of Postgrauate Medical Education and Research, Puducherry, India.
Department of Radiodiagnosis, Jawaharlal Institute of Postgrauate Medical Education and Research, Puducherry, India.
Saudi J Anaesth. 2018 Oct-Dec;12(4):606-611. doi: 10.4103/sja.SJA_240_18.
Rapid sequence induction and intubation (RSII) with application of "Cricoid pressure" and avoidance of "facemask ventilation" (FMV) is believed to minimize the risk of pulmonary aspiration of gastric contents during general anesthesia. However, some patients may be at risk of developing hypoxemia and may benefit from FMV during RSII. The purpose of this study was to assess the effectiveness of "cricoid pressure" in preventing gastric insufflation during FMV using gastric ultrasonography.
Eighty-four adult patients were randomized to receive cricoid pressure (CP) or no cricoid pressure (NCP), during FMV after induction of general anesthesia. Gastric antral cross-sectional area (CSA) was measured with ultrasonography before and after FMV in supine and right lateral decubitus positions (LDP). Appearance of "comet tail" artifacts created by acoustic shadows of gas in the gastric antrum was noted.
The incidence of insufflation indicated by "comet tail" artifacts during FMV was lower in group CP (17 vs 71%; < 0.001). The lowest at which gastric insufflation occurred was higher in group CP (20 vs 14 cmHO). The change in mean gastric antral CSA was significantly lower in group CP than in group NCP in supine (0.02 vs 0.36 cm, = 0.012) and right LDP (0.03 vs 0.67 cm, < 0.001).
Cricoid pressure is effective in preventing gastric insufflation during FMV at less than 20 cmHO. Observation of comet tail artifacts in gastric antrum along with measurement of change in antral CSA on ultrasound examination is a feasible and reliable method to detect gastric insufflation.
快速顺序诱导插管（RSII）联合应用“环状软骨压迫法”并避免“面罩通气”（FMV）被认为可将全身麻醉期间胃内容物肺误吸的风险降至最低。然而，一些患者可能有发生低氧血症的风险，在RSII期间可能受益于FMV。本研究的目的是使用胃超声评估“环状软骨压迫法”在FMV期间预防胃内气体充盈的有效性。
84例成年患者在全身麻醉诱导后接受FMV时被随机分为接受环状软骨压迫（CP）组或不接受环状软骨压迫（NCP）组。在仰卧位和右侧卧位（LDP）进行FMV前后，用超声测量胃窦横截面积（CSA）。记录胃窦内气体声影产生的“彗尾”伪像的出现情况。
FMV期间由“彗尾”伪像提示的气体充盈发生率在CP组较低（17%对71%；<0.001）。发生胃内气体充盈的最低气道压在CP组较高（20cmH₂O对14cmH₂O）。仰卧位（0.02cm²对0.36cm²，P = 0.012）和右侧LDP位（0.03cm²对0.67cm²，P<0.001）时，CP组胃窦平均CSA的变化显著低于NCP组。
在气道压低于20cmH₂O的FMV期间，环状软骨压迫法可有效预防胃内气体充盈。超声检查时观察胃窦内的彗尾伪像并测量胃窦CSA的变化是检测胃内气体充盈的一种可行且可靠的方法。
