Design of a Portable Venomanometer System for Episcleral Venous Pressure Measurement

Author(s):  
Tze Yeen Yap ◽  
Carl A. Nelson ◽  
Deepta Ghate ◽  
Vikas Gulati ◽  
Shan Fan ◽  
...  

Abstract Traumatic brain injury (TBI) has been considered a precarious health issue especially within the military population. Research has shown that early treatment of TBI could reduce possible neurocognitive injury. However, the nature of military triage has created challenges for early TBI detection. Intracranial pressure (ICP), which is used as a biomarker of outcomes in TBI, is not only expensive to measure but is also invasive and requires specialized surgical and procedural skills. Episcleral venous pressure (EVP) was proven to be a good alternative biomarker to ICP. However, the current technology in measuring EVP is not portable, and requires a skilled operator with a slit-lamp for testing. Moreover, the measurement is highly subjective and depends on the operator’s skill and technique. Therefore, there is a critical need for alternative technology for non-clinical TBI diagnosis. In this paper, we present an improved venomanometer design for measuring EVP in the field.

2020 ◽  
Author(s):  
Li Hong Peng ◽  
Lin Ying Ning ◽  
Cheng Zhi Hui ◽  
Qu Wei ◽  
Zhang Liu ◽  
...  

Abstract Background: Mechanical ventilation (MV) with positive end-expiratory pressure (PEEP) is commonly applied in patients with severe traumatic brain injury (sTBI). However, the individual responsiveness of intracranial pressure (ICP) to PEEP varies. Thus, identifying an indicator detecting ICP responsiveness to PEEP is of great significance. As central venous pressure (CVP) could act as an intermediary to transduce pressure from PEEP to ICP, we developed a new indicator, PICGap, representing the gap between baseline ICP and baseline CVP. The aim of the current study was to explore the relationship between PICGap and ICP responsiveness to PEEP. Methods: A total of 112 patients with sTBI undergoing MV were enrolled in this prospective cohort study. ICP, CVP, cerebral perfusion pressure (CPP), static compliance of the respiratory system (Cst), and end-tidal carbon dioxide pressure (PetCO2) were recorded at the initial (3 cmH2O) and adjusted (15 cmH2O) levels of PEEP. PICGap was assessed as baseline ICP - baseline CVP (when PEEP=3 cmH2O). The patients were classified into the ICP responder and non-responder groups based on whether ICP increment with PEEP adjusted from 3 cmH2O to 15 cmH2O was greater than 20% of baseline ICP. The above parameters were compared between the two groups, and prediction of ICP responsiveness to PEEP adjustment was evaluated by receiver operating characteristic (ROC) curve analysis. Results: Compared with the non-responder group, the responder group had lower PICGap (1.63±1.33 versus 6.56±2.46 mmHg; p<0.001), lower baseline ICP, and higher baseline CVP. ROC curve analysis suggested that PICGap was a stronger predictive indicator of ICP responsiveness to PEEP (AUC=0.957, 95%CI 0.918-0.996; p<0.001) compared with baseline ICP and baseline CVP, with favorable sensitivity (95.24%, 95%CI 86.91%-98.70%) and specificity (87.6%, 95%CI 75.76%-94.27%), at a cut off value of 2.5 mmHg. Conclusion: The impact of PEEP on ICP depends on the gap between baseline ICP and baseline CVP, i.e. PICGap. In addition, PICGap is a potential predictor of ICP responsiveness to PEEP adjustment in patients with sTBI.


Critical Care ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Daniel Agustin Godoy ◽  
Rafael Badenes ◽  
Paolo Pelosi ◽  
Chiara Robba

AbstractMaintaining an adequate level of sedation and analgesia plays a key role in the management of traumatic brain injury (TBI). To date, it is unclear which drug or combination of drugs is most effective in achieving these goals. Ketamine is an agent with attractive pharmacological and pharmacokinetics characteristics. Current evidence shows that ketamine does not increase and may instead decrease intracranial pressure, and its safety profile makes it a reliable tool in the prehospital environment. In this point of view, we discuss different aspects of the use of ketamine in the acute phase of TBI, with its potential benefits and pitfalls.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. Harrois ◽  
◽  
J. R. Anstey ◽  
F. S. Taccone ◽  
A. A. Udy ◽  
...  

Following publication of the original article [1], we were notified that the collaborators’ names part of the “The TBI Collaborative” group has not been indexed in Pubmed. Below the collaborators names full list:


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