Padayachy Llewellyn C, Rohlwink Ursula, Zwane Eugene, Fieggen Graham, Peter Jonathan C, Figaji Anthony A
Pediatric Neurosurgery, School of Child and Adolescent Health, Red Cross War Memorial Children's Hospital, University of Cape Town, Rondebosch 8001, Cape Town, South Africa.
Childs Nerv Syst. 2012 Nov;28(11):1911-8. doi: 10.1007/s00381-012-1837-2. Epub 2012 Jun 17.
The frequency of adverse events, such as cerebral ischemia, following traumatic brain injury (TBI) is often debated. Point-in-time monitoring modalities provide important information, but have limited temporal resolution.
This study examines the frequency of an adverse event as a point prevalence at 24 and 72 h post-injury, compared with the cumulative burden measured as a frequency of the event over the full duration of monitoring.
Reduced brain tissue oxygenation (PbtO(2) < 10 mmHg) was the adverse event chosen for examination. Data from 100 consecutive children with severe TBI who received PbtO(2) monitoring were retrospectively examined, with data from 87 children found suitable for analysis. Hourly recordings were used to identify episodes of PbtO(2) less than 10 mmHg, at 24 and 72 h post-injury, and for the full duration of monitoring.
Reduced PbtO(2) was more common early than late after injury. The point prevalence of reduced PbtO(2) at the selected time points was relatively low (10 % of patients at 24 h and no patients at the 72-h mark post-injury). The cumulative burden of these events over the full duration of monitoring was relatively high: 50 % of patients had episodes of PbtO(2) less than 10 mmHg and 88 % had PbtO(2) less than 20 mmHg.
Point-in-time monitoring in a dynamic condition like TBI may underestimate the overall frequency of adverse events, like reduced PbtO(2), particularly when compared with continuous monitoring, which also has limitations, but provides a dynamic assessment over a longer time period.
创伤性脑损伤（TBI）后诸如脑缺血等不良事件的发生率常常存在争议。即时监测方式能提供重要信息，但时间分辨率有限。
本研究旨在考察损伤后24小时和72小时不良事件的时点患病率，并与在整个监测期间该事件发生频率所衡量的累积负担进行比较。
选择脑组织氧合降低（脑组织氧分压[PbtO₂]<10 mmHg）作为待考察的不良事件。回顾性分析了100例接受PbtO₂监测的重度TBI连续患儿的数据，其中87例患儿的数据适合分析。利用每小时记录来确定损伤后24小时和72小时以及整个监测期间PbtO₂低于10 mmHg的发作情况。
PbtO₂降低在损伤早期比晚期更常见。在选定时间点，PbtO₂降低的时点患病率相对较低（损伤后24小时为10%的患者，损伤后72小时无患者）。这些事件在整个监测期间的累积负担相对较高：50%的患者有PbtO₂低于10 mmHg的发作，88%的患者有PbtO₂低于20 mmHg的发作。
在TBI这种动态情况下的即时监测可能会低估不良事件的总体发生率，如PbtO₂降低，特别是与连续监测相比时，连续监测虽也有局限性，但能在更长时间段内提供动态评估。
