McCarter Ryan N, Moayedi Siamak, Witting Michael D
University of Maryland School of Medicine, Baltimore, Maryland.
Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, Maryland.
J Emerg Med. 2018 Jul;55(1):29-33. doi: 10.1016/j.jemermed.2018.04.011.
The Easy IJ procedure involves placement of a 4.8-cm intravenous catheter into the internal jugular (IJ) vein using ultrasound guidance. It is not known whether this needle length has the potential to cause a pneumothorax.
The objective of this study was to determine if a radiographic "safe margin" exists. We hypothesized that an average margin of ≥2 cm would exist between the catheter tip and the pleura.
Operators used a central approach to the IJ vein. We reviewed radiographic images taken immediately after the Easy IJ procedure. Using digital software, we measured the distance from the catheter tip to the closest point of the pleura and from the catheter tip to the level of the lung apex. We defined distances exceeding the margin of safety-either passing the pleura or ending inferior to the apex-as negative for the purpose of calculating an average. We used the t distribution to calculate 95% confidence intervals (CIs) for average values.
Radiographs showing the catheter tip were available from 62 patients. The mean needle-to-pleura distance was -0.1 cm (95% CI -0.7 to 0.5 cm). The mean vertical distance to the apex was -0.2 cm (95% CI -0.8 to 0.3 cm), with a standard deviation of 2.25 cm.
Radiographic analysis failed to show a margin of safety for the Easy IJ procedure. Postprocedure imaging may still be necessary to exclude pneumothorax.
简易颈内静脉穿刺术是在超声引导下将一根4.8厘米的静脉导管置入颈内静脉。尚不清楚这种针的长度是否有导致气胸的可能性。
本研究的目的是确定是否存在影像学上的“安全 margin”。我们假设导管尖端与胸膜之间平均 margin≥2厘米。
操作者采用中心入路穿刺颈内静脉。我们回顾了简易颈内静脉穿刺术后立即拍摄的影像学图像。使用数字软件，我们测量了导管尖端到胸膜最近点的距离以及导管尖端到肺尖水平的距离。为了计算平均值，我们将超过安全 margin 的距离（即穿过胸膜或在肺尖下方结束的距离）定义为负数。我们使用t分布计算平均值的95%置信区间（CIs）。
有62例患者的X线片显示了导管尖端。针到胸膜的平均距离为-0.1厘米（95%CI -0.7至0.5厘米）。到肺尖的平均垂直距离为-0.2厘米（95%CI -0.8至0.3厘米），标准差为2.25厘米。
影像学分析未能显示简易颈内静脉穿刺术的安全 margin。术后影像学检查可能仍有必要以排除气胸。
