Real-Time models to predict the use of vasopressors in monitored patients

The needs of reducing human error has been growing in every field of study, and medicine is one of those. Through the implementation of technologies is possible to help in the decision making process of clinics, therefore to reduce the difficulties that are typically faced. This study focuses on easing some of those difficulties by presenting real-time data mining models capable of predicting if a monitored patient, typically admitted in intensive care, will need to take vasopressors. Data Mining models were induced using clinical variables such as vital signs, laboratory analysis, among others. The best model presented a sensitivity of 94.94%. With this model it is possible reducing the misuse of vasopressors acting as prevention. At same time it is offered a better care to patients by anticipating their treatment with vasopressors

Abnormal liver function tests in acute heart failure: relationship with clinical characteristics and outcome in the PROTECT study

Aims: Episodes of acute heart failure (AHF) unfavourably affect multiple organs, which may have an adverse impact on the outcomes. We investigated the prevalence and clinical consequences of abnormal liver function tests (LFTs) in AHF patients enrolled in the PROTECT study. Methods and results: The LFTs comprised serial assessment of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and albumin at baseline and during follow-up (daily until discharge, on days 7 and 14). The prevalence of abnormal LFTs (above upper limit of normal for AST and ALT or below lower limit of normal for albumin) was: at baseline AST 20%, ALT 12%, albumin 40%; and at day 14: AST 15%, ALT 9%, albumin 26%. Abnormal LFTs at baseline were associated with a higher risk of in-hospital death with odds ratios [95% confidence interval (CI)] of 3.5 (1.7–7.3) for AST, 3.9 (1.8–8.4) for ALT, and 2.8 (1.3–5.9) for albumin (all P < 0.01). Abnormal baseline and discharge LFTs had an unfavourable impact on 180-day mortality with hazard ratios (95% CI) for baseline AST, ALT, and albumin of 1.3 (1.0–1.7), 1.1 (1.0–1.2), 1.4 (1.1–1.8), respectively, and 1.5 (1.1–2.0), 1.5 (1.0–2.2), and 1.6 (1.2–2.1), for discharge AST, ALT, albumin, respectively (all P < 0.05). Analysis of LFTs trajectories (calculated as changes in LFTs over time) revealed that increasing AST and ALT on day 3 as well as decreasing albumin on day 4 were independent prognosticators of 180-day outcome (all P < 0.05). Conclusions: Abnormal LFTs are frequent in AHF at baseline and during hospital stay and predict worse outcomes. Whether this association is causal and what are the underlying mechanisms involved require further study

Pervasive patient timeline for intensive care units

This research work explores a new way of presenting and representing information about patients in critical care, which is the use of a timeline to display information. This is accomplished with the development of an interactive Pervasive Patient Timeline able to give to the intensivists an access in real-time to an environment containing patients clinical information from the moment in which the patients are admitted in the Intensive Care Unit (ICU) until their discharge This solution allows the intensivists to analyse data regarding vital signs, medication, exams, data mining predictions, among others. Due to the pervasive features, intensivists can have access to the timeline anywhere and anytime, allowing them to make decisions when they need to be made. This platform is patient-centred and is prepared to support the decision process allowing the intensivists to provide better care to patients due the inclusion of clinical forecasts.FCT -Fundação para a Ciência e a Tecnologia(PTDC/EEI-SII/1302/2012

Targeted Perfusion Therapy in Spinal Cord Trauma.

We review state-of-the-art monitoring techniques for acute, severe traumatic spinal cord injury (TSCI) to facilitate targeted perfusion of the injured cord rather than applying universal mean arterial pressure targets. Key concepts are discussed such as intraspinal pressure and spinal cord perfusion pressure (SCPP) at the injury site, respectively, analogous to intracranial pressure and cerebral perfusion pressure for traumatic brain injury. The concept of spinal cord autoregulation is introduced and quantified using spinal pressure reactivity index (sPRx), which is analogous to pressure reactivity index for traumatic brain injury. The U-shaped relationship between sPRx and SCPP defines the optimum SCPP as the SCPP that minimizes sPRx (i.e., maximizes autoregulation), and suggests that not only ischemia but also hyperemia at the injury site may be detrimental. The observation that optimum SCPP varies between patients and temporally in each patient supports individualized management. We discuss multimodality monitoring, which revealed strong correlations between SCPP and injury site metabolism (tissue glucose, lactate, pyruvate, glutamate, glycerol), monitored by surface microdialysis. Evidence is presented that the dura is a major, but unappreciated, cause of spinal cord compression after TSCI; we thus propose expansion duroplasty as a novel treatment. Monitoring spinal cord blood flow at the injury site has revealed novel phenomena, e.g., 3 distinct blood flow patterns, local steal, and diastolic ischemia. We conclude that monitoring from the injured spinal cord in the intensive care unit is a safe technique that appears to enable optimized and individualized spinal cord perfusion

Clinical Applications of Neuromonitoring Following Acute Brain Injury

Various invasive and non-invasive cranial monitoring techniques can be applied clinically to describe the extent to which cerebral hemodynamics and subsequently, patient outcome, have been impacted following acute brain injury (ABI). This Ph.D. thesis examines both prospective and retrospective patient data in both neurocritical and general intensive care patients. Thirty neurotrauma patients and forty general intensive care patients with neurological complications were prospectively monitored after ABI. Retrospective patient data was harvested from a database of 1,023 traumatic brain injury (TBI) patients with invasive intracranial pressure (ICP), arterial blood pressure (ABP), and transcranial Doppler ultrasonography (TCD) recordings. Data analysis focused on ICP microsensor accuracy, compensatory reserve, the pulsatility of brain signals (ICP and TCD), and cerebral arterial blood volume (CaBV) based on TCD. The main results are summarized below: I. Intracranial hypertension has a profound negative influence on cerebrovascular parameters and patient outcome. II. ICP microsensor accuracy is limited, with an average error of approximately ± 6.0 mm Hg. III. ICP weighted with the compensatory reserve better predicts outcome than mean ICP alone. IV. ICP and TCD pulsatility are functions of mean ICP and cerebral perfusion pressure (CPP). V. Continuous blood flow forward (CFF) and pulsatile blood flow forward (PFF) models can approximate CaBV with derived TCD signals; CFF best models TCD pulsatility. VI. The pressure reactivity index (PRx) and the pulse amplitude index (PAx) can be estimated non-invasively using slow waves of TCD estimated by CaBV with similar outcome-predictive power. VII. Multi-parametric TCD-based monitoring of general intensive care patients is clinically feasible; the joint estimation of autoregulation, dysautonomia, non-invasive ICP, and critical closing pressure is possible. The culmination of these projects should have an impact on current monitoring practices in ABI patients, emphasizing the continued validation and refinement of TCD methodology in clinical neurosciences

Detection of exhaled methane levels for monitoring trauma-related haemorrhage following blunt trauma: study protocol for a prospective observational study

Early recognition and effective treatment of internal bleeding impose a cardinal challenge for trauma teams. The reduction of the superior mesenteric artery (SMA) blood flow is among the first compensatory responses to blood loss, thus being a promising candidate as a diagnostic tool for occult haemorrhage. Unfortunately, methods for monitoring the SMA flow have not been elaborated to date. Nevertheless, animal experiments suggest that exhaled methane (CH4) levels correspond to the SMA perfusion. We hypothesise that real-time detection of CH4 concentrations in the exhaled air is an applicable technique for the early recognition of haemorrhage in severely injured patients. We also hypothesise that exhaled CH4 levels reflect the volume of blood loss more accurately than conventional markers of blood loss and shock such as shock index, haemoglobin, base deficit, lactate, end-tidal carbon dioxide and sublingual microcirculatory indices.One hundred and eleven severely injured (Injury Severity Score ≥16), intubated, bleeding patients sustaining blunt trauma will be included in this prospective observational study. Blood loss will be detected with CT and estimated with CT-linked radiologic software. Exhaled CH4 concentrations will be monitored by attaching a near-infrared laser technique-based photoacoustic spectroscopy apparatus to the exhalation outlet of the ventilator on patient arrival. The primary outcome is the volume of blood loss. Need for massive transfusion and 24-hour mortality will constitute secondary outcomes. The relation of exhaled CH4 to study outcomes and its performance in predicting blood loss in comparison with conventional shock markers and microcirculatory indices will be tested.Our protocol (ID: 5400/2021-SZTE) has been registered on ClinicalTrials.gov (NCT04987411) and complies with the Declaration of Helsinki and has been approved by the medical ethics committee at the University of Szeged (Ref.nr.:121/2021-SZTE RKEB). It is in data collection phase, theresults will be shared with the scientific community through publication in a peer-reviewed journal.NCT04987411; ClinicalTrials.gov, registered on 27 July 2021

Improving the acute and perioperative hemodynamic assessment

First, this thesis aimed to extend the evidence on the applicability of hemodynamic monitoring during the perioperative period and after admission to the ICU. Second, we aimed to gain knowledge on how to improve the conduct of studies in perioperative and critical care medicine.We provided an overview of the current evidence for hemodynamic monitoring in perioperative goal-directed therapy. We showed that the studies on this subject showed clinical heterogeneity and risk of bias. Extension of all aspects of hemodynamic monitoring was considered in this thesis. A study was performed on the educated guess of physicians when estimating cardiac output using clinical examination to help improve the reliability of the clinical examination. We showed that physicians at the bed-side mainly consider mottling score and norepinephrine dose when estimating cardiac output. In another study, we demonstrated that blood pressure measurements differ when measured invasively or non-invasively and that these differences may have clinical consequences. We also showed that echocardiography could be performed by novices, but experts are needed to interpret obtained images. We demonstrated that cardiac output measurements vary in critically ill patients when measured with echocardiography or uncalibrated pulse wave analysis.For the second part of this thesis, we demonstrated that various mortality prediction models exist for critically ill patients. Quality of methodology often lacks for these models, and improvements have to be made to help patient care. To help improve the quality of studies, we finally propose that study protocols are prepublished and made available for peer-review before conduct