Brunetti Domenico Junior, Leonardis Francesca, Frisardi Francesca, Dauri Mario, Deana Cristian, Aspide Raffaele, Cammarota Gianmaria, Pisani Luigi, Adorno Rossella, Polidoro Roberto, Tiseo Marco, Sergi Paola Giuseppina, Vetrugno Luigi, Mascia Luciana, Biasucci Daniele Guerino
Intensive Care Unit, Tor Vergata' University Hospital, Rome, Italy.
Department of Clinical Science and Translational Medicine, 'Tor Vergata' University of Rome, Rome, Italy.
Neurocrit Care. 2025 Mar 25. doi: 10.1007/s12028-025-02240-1.
Prone positioning is recommended in acute respiratory distress syndrome (ARDS) to ensure adequate gas exchange. However, it may lead to an increase in intracranial pressure (ICP), mostly due to a reduction of venous return from the brain. ICP can be noninvasively estimated with transcranial color-coded Doppler (TCCD) using methods based on the relationships between the pulsatility index (PI) and ICP or methods based on the estimate of cerebral perfusion pressure (eCPP) and estimate of ICP (eICP). This study was aimed at assessing the effects of a 30° reverse Trendelenburg ('head up') prone position on two noninvasive estimators of ICP (eICP and PI).
This is a cross-over, longitudinal, physiological study conducted on a cohort of adult patients fulfilling Berlin definition criteria for moderate to severe ARDS without brain injury but with clinical indication to prone positioning. We registered TCCD parameters of cerebral hemodynamic and systemic hemodynamic parameters, blood gas exchange data, and respiratory mechanics parameters in a horizonal supine position, in a 30° semirecumbent supine position, in the standard prone position, and, finally, in the 30° 'head up' prone position, obtained by tilting the entire bed to a reverse Trendelenburg position. One-way repeated measures analysis of variance was used to analyze data.
In 20 patients included, switching from a supine position to the standard prone position resulted in a significant increase in mean ± SD PI (from 0.99 ± 0.22 to 1.29 ± 0.25, p < 0.01) and eICP (from 12.5 ± 3.8 to 17.5 ± 4.1, p < 0.01), whereas moving from this latter position to the 'head up' prone position resulted in a decrease in the mean ± SD PI (from 1.29 ± 0.25 to 1.0 ± 0.23, p < 0.01). Hemodynamic and respiratory mechanics parameters did not differ.
The 30° 'head up' prone position may limit the increase in PI in moderate to severe ARDS without brain injury. As a noninvasive estimator of ICP, PI may allow detection of changes in ICP when moving from the 'head up' semirecumbent supine position to the standard prone position and from this latter position to the 'head up' prone position.
对于急性呼吸窘迫综合征（ARDS）患者，推荐采用俯卧位以确保充分的气体交换。然而，这可能会导致颅内压（ICP）升高，主要原因是脑静脉回流减少。可以使用基于搏动指数（PI）与ICP之间关系的方法或基于脑灌注压（eCPP）和ICP估计值（eICP）的方法，通过经颅彩色编码多普勒（TCCD）对ICP进行无创估计。本研究旨在评估30°反向头低脚高位（“头高位”）俯卧位对两种ICP无创估计指标（eICP和PI）的影响。
这是一项针对符合中度至重度ARDS柏林定义标准、无脑损伤但有俯卧位临床指征的成年患者队列进行的交叉、纵向生理学研究。我们记录了水平仰卧位、30°半卧位仰卧位、标准俯卧位以及最后通过将整个床倾斜到头低脚高位获得的30°“头高位”俯卧位下的脑血流动力学TCCD参数、全身血流动力学参数、血气交换数据和呼吸力学参数。采用单向重复测量方差分析来分析数据。
纳入的20例患者中，从仰卧位转换到标准俯卧位导致平均±标准差PI显著升高（从0.99±0.22升至1.29±0.25，p<0.01）以及eICP升高（从12.5±3.8升至17.5±4.1，p<0.01），而从后者位置转换到“头高位”俯卧位导致平均±标准差PI降低（从1.29±0.25降至1.0±0.23，p<0.01）。血流动力学和呼吸力学参数无差异。
30°“头高位”俯卧位可能会限制无脑损伤的中度至重度ARDS患者PI的升高。作为ICP的无创估计指标，PI可能有助于检测从“头高位”半卧位仰卧位转换到标准俯卧位以及从后者位置转换到“头高位”俯卧位时ICP的变化。
