PDF(Pubmed)
Abstract：
Intracranial pressure (ICP) burden or pressure time dose (PTD) is a valuable clinical indicator for pending intracranial hypertension, mostly based on threshold exceedance. Pulse frequency and waveform morphology (WFM) of the ICP signal contribute to PTD. The temporal resolution of the ICP signal has a great influence on PTD calculation but has not been systematically studied yet. Hence, the temporal resolution of the ICP signal on PTD calculation is investigated. We retrospectively analysed continuous 48 h ICP recordings with high temporal resolution obtained from 94 patients at the intensive care unit who underwent neurosurgery due to an intracranial haemorrhage and received an intracranial pressure probe (43 females, median age: 72 years, range: 23 to 88 years). The cumulative area under the curve above the threshold of 20 mmHg was compared for different temporal resolutions of the ICP signal (beat-to-beat, 1 s, 300 s, 1800 s, 3600 s). Events with prolonged ICP elevation were compared to those with few isolated threshold exceedances. PTD increased for lower temporal resolutions independent of WFM and frequency of threshold exceedance. PTDbeat-to-beat best reflected the impact of frequency of threshold exceedance and WFM. Events that could be distinguished in PTDbeat-to-beat became magnified more than 7-fold in PTD1s and more than 104 times in PTD1h, indicating an overestimation of PTD. PTD calculation should be standardised, and beat-by-beat PTD could serve as an easy-to-grasp indicator for the impact of frequency and WFM of ICP elevations on ICP burden.
摘要：
颅内压（ICP）负荷或压力时间剂量（PTD）是一个有价值的临床指标，为即将发生的颅内高压，主要基于阈值超标。ICP信号的脉冲频率和波形形态(WFM)有助于PTD。ICP信号的时间分辨率对PTD计算有很大影响，但尚未进行系统研究。因此，研究了ICP信号在PTD计算中的时间分辨率。我们回顾性分析了从重症监护病房的94例因颅内出血而接受神经外科手术并接受颅内压探头的患者（43例女性，平均年龄：72岁，范围：23至88年）。对于ICP信号的不同时间分辨率（搏动到搏动，1s,300s,1800s,3600秒)。将ICP升高时间延长的事件与孤立阈值超标的事件进行比较。对于较低的时间分辨率，PTD增加，与WFM和阈值超标的频率无关。PTDbeat-to-beat最好地反映了阈值超标频率和WFM的影响。在PTDbeat-to-beat中可以区分的事件在PTD1中放大了7倍以上，在PTD1h中放大了104倍以上，表明PTD的高估。PTD计算应标准化，和逐次搏动PTD可以作为ICP升高的频率和WFM对ICP负担的影响的易于掌握的指标。
