Bedside Monitoring Tool Research Articles

Finger photopletysmography detects early acute blood loss in compensated blood donors: a pilot study

Objective. Diagnosis of incipient acute hypovolemia is challenging as vital signs are typically normal and patients remain asymptomatic at early stages. The early identification of this entity would affect patients’ outcome if physicians were able to treat it precociously. Thus, the development of a noninvasive, continuous bedside monitoring tool to detect occult hypovolemia before patients become hemodynamically unstable is clinically relevant. We hypothesize that pulse oximeter’s alternant (AC) and continuous (DC) components of the infrared light are sensitive to acute and small changes in patient’s volemia. We aimed to test this hypothesis in a cohort of healthy blood donors as a model of slight hypovolemia. Approach. We planned to prospectively study blood donor volunteers removing 450 ml of blood in supine position. Noninvasive arterial blood pressure, heart rate, and finger pulse oximetry were recorded. Data was analyzed before donation, after donation and during blood auto-transfusion generated by the passive leg-rising (PLR) maneuver. Main results. Sixty-six volunteers (44% women) accomplished the protocol successfully. No clinical symptoms of hypovolemia, arterial hypotension (systolic pressure < 90 mmHg), brady-tachycardia (heart rate <60 and >100 beats-per-minute) or hypoxemia (SpO2 < 90%) were observed during donation. The AC signal before donation (median 0.21 and interquartile range 0.17 a.u.) increased after donation [0.26(0.19) a.u; p < 0.001]. The DC signal before donation [94.05(3.63) a.u] increased after blood extraction [94.65(3.49) a.u; p < 0.001]. When the legs’ blood was auto-transfused during the PLR, the AC [0.21(0.13) a.u.; p = 0.54] and the DC [94.25(3.94) a.u.; p = 0.19] returned to pre-donation levels. Significance. The AC and DC components of finger pulse oximetry changed during blood donation in asymptomatic volunteers. The continuous monitoring of these signals could be helpful in detecting occult acute hypovolemia. New pulse oximeters should be developed combining the AC/DC signals with a functional hemodynamic monitoring of fluid responsiveness to define which patient needs fluid administration.

Flow starvation during square-flow assisted ventilation detected by supervised deep learning techniques

BackgroundFlow starvation is a type of patient-ventilator asynchrony that occurs when gas delivery does not fully meet the patients’ ventilatory demand due to an insufficient airflow and/or a high inspiratory effort, and it is usually identified by visual inspection of airway pressure waveform. Clinical diagnosis is cumbersome and prone to underdiagnosis, being an opportunity for artificial intelligence. Our objective is to develop a supervised artificial intelligence algorithm for identifying airway pressure deformation during square-flow assisted ventilation and patient-triggered breaths.MethodsMulticenter, observational study. Adult critically ill patients under mechanical ventilation > 24 h on square-flow assisted ventilation were included. As the reference, 5 intensive care experts classified airway pressure deformation severity. Convolutional neural network and recurrent neural network models were trained and evaluated using accuracy, precision, recall and F1 score. In a subgroup of patients with esophageal pressure measurement (ΔPes), we analyzed the association between the intensity of the inspiratory effort and the airway pressure deformation.Results6428 breaths from 28 patients were analyzed, 42% were classified as having normal-mild, 23% moderate, and 34% severe airway pressure deformation. The accuracy of recurrent neural network algorithm and convolutional neural network were 87.9% [87.6–88.3], and 86.8% [86.6–87.4], respectively. Double triggering appeared in 8.8% of breaths, always in the presence of severe airway pressure deformation. The subgroup analysis demonstrated that 74.4% of breaths classified as severe airway pressure deformation had a ΔPes > 10 cmH2O and 37.2% a ΔPes > 15 cmH2O.ConclusionsRecurrent neural network model appears excellent to identify airway pressure deformation due to flow starvation. It could be used as a real-time, 24-h bedside monitoring tool to minimize unrecognized periods of inappropriate patient-ventilator interaction.

Whole lung lavage decreases physiological dead space in patients with pulmonary alveolar proteinosis: two case reports

BackgroundPulmonary alveolar proteinosis (PAP) is a rare disease characterized by progressive accumulation of the alveolar surfactant. Whole lung lavage (WLL) using a high volume of warmed saline remains the standard therapy. However, no established bedside monitoring tool can evaluate the physiological effect of WLL in the perioperative period. Indirect calorimetry, which is generally used to measure resting energy expenditure, can detect carbon dioxide (CO2) production and mixed-expired partial pressure of CO2 breath by breath. In this physiological study, we calculated CO2 elimination per breath (VTCO2,br) and Enghoff’s dead space using indirect calorimetry and measured the extravascular lung water index to reveal the effect of WLL.Case presentationWe measured VTCO2,br, Enghoff’s dead space, and the extravascular lung water and cardiac indices before and after WLL to assess the reduction in shunt by washing out the surfactant. A total of four WLLs were performed in two PAP patients. The first case involved an Asian 62-year-old man who presented with a 3-month history of dyspnea on exertion. The second case involved an Asian 48-year-old woman with no symptoms. VTCO2,br increased, and the Enghoff’s dead space decreased at 12 h following WLL. An increase in the extravascular lung water was detected immediately following WLL, leading to a transient increase in Enghoff’s dead space.ConclusionWLL can increase efficient alveolar ventilation by washing out the accumulated surfactant. However, the lavage fluid may be absorbed into the lung tissues immediately after WLL and result in an increase in the extravascular lung water.

Preventing unrecognized deterioration & improving outcomes of critically ill patients using the National Early Warning Score 2 in a high dependency unit in Bangladesh: A quality improvement project.

This Quality Improvement Project (QIP) aimed to assess the acceptability and utility of the National Early Warning Score 2 (NEWS2) in a Bangladeshi level-2 care setting. All nurses and physicians were trained on NEWS2 scores and a proper response before starting the QIP. Utilization of NEWS2 and patient outcome were documented and analyzed. Acceptability was acknowledged by increase in utilization, and utility by reduction in unrecognized deterioration of patients. The modified NEWS2 was well adopted and utilized by the nursing staff. There was a statistically significant reduction in unrecognized deterioration leading to cardiac arrest and the need for transfer to the Intensive Care Unit after implementation of NEWS2. With adequate training, motivation and appropriate modification, NEWS2 can become a well-accepted, widely adopted and realistic bedside monitoring tool in resource-limited settings like Bangladesh.

Prevention of Unnoticed Deterioration And Improvement In Outcome of Critically Ill Patients By Implementation of National Early Warning Score 2 In A High Dependency Unit In Bangladesh: A Quality Improvement Project

This Quality Improvement Project (QIP) was aimed to assess the acceptability and utility of the National Early Warning Score 2 (NEWS2) in a Bangladeshi level-2 care setting.All nurses and physicians were trained on NEWS2 scores and proper response before starting the QIP. Utilization of NEWS2 and patient outcome were documented and analyzed. Acceptability was recognized by increase in utilization, and utility by reduction in unnoticed deterioration of patients. With modified NEWS2 chart, it became well adopted and utilized by the nurses. Data from 3828 patients showed statistically significant reduction in unnoticed deterioration evident by lowering of sudden cardiac arrest and ICU transfer (0.35% vs 2.6% and 2.33% vs 6.6%, p= &lt;0.0005) after and before implementation of the NEWS2, respectively.With adequate training, motivation, and appropriate modification, the NEWS2 can become a well-accepted, widely adopted, and realistic bedside monitoring tool in resource limited settings like Bangladesh. Bangladesh J Medicine 2023; Vol. 34, No. 2(1) Supplement: 188

Clinicians’ perspectives on wearable sensor technology as an alternative bedside monitoring tool in two West African countries

ObjectiveHealthcare facilities in low- and middle-income countries (LMICs), especially in Africa, suffer from a lack of continuous bedside monitoring capability, adversely affecting timely detection of hemodynamic deterioration and the opportunity for life-saving intervention. Wearable device technologies can overcome many of the challenges of conventional bedside monitors and could be viable alternatives. We assessed clinicians’ perspectives on the use of a novel experimental wearable device (“biosensor”) to improve bedside monitoring of pediatric patients in two West African LMICs. MethodsFocus groups were conducted in 3 hospitals (2 in Ghana and 1 in Liberia), in both urban and rural settings and of variable size, to elucidate clinicians’ attitudes about the biosensor and to identify potential implementation needs. The focus group sessions were coded using a constant comparative method. Deductive thematic analysis was applied to pair themes with Consolidated Framework for Implementation Research (CFIR) contextual factors and domains. ResultsFour focus groups were conducted in October 2019, and included 9 physicians, 20 nurses, and 20 community health workers. Fifty-two codes in four thematic areas were linked to 3 CFIR contextual factors and 9 domains. Key themes were durability and cost of the biosensor, hospital setting, and staffing concerns, which were related to the “Inner Setting” and “Characteristics of the Intervention” CFIR contextual factors. Participants, who recognized the limitations of current vital sign monitoring systems, further identified 21 clinical settings in which a biosensor could potentially be useful and expressed willingness to implement the biosensor. ConclusionClinicians who provide care to pediatric patients in two West African LMICs suggested multiple uses of a novel experimental wearable biosensor and expressed willingness to use it for continuous bedside vital sign monitoring. They identified device design (e.g., durability, cost), hospital setting (rural vs urban), and staffing as important factors to consider during further development and implementation.

Prone positioning improves ventilation–perfusion matching assessed by electrical impedance tomography in patients with ARDS: a prospective physiological study

BackgroundThe physiological effects of prone ventilation in ARDS patients have been discussed for a long time but have not been fully elucidated. Electrical impedance tomography (EIT) has emerged as a tool for bedside monitoring of pulmonary ventilation and perfusion, allowing the opportunity to obtain data. This study aimed to investigate the effect of prone positioning (PP) on ventilation–perfusion matching by contrast-enhanced EIT in patients with ARDS.DesignMonocenter prospective physiologic study.SettingUniversity medical ICU.PatientsTen mechanically ventilated ARDS patients who underwent PP.InterventionsWe performed EIT evaluation at the initiation of PP, 3 h after PP initiation and the end of PP during the first PP session.Measurements and main resultsThe regional distribution of ventilation and perfusion was analyzed based on EIT images and compared to the clinical variables regarding respiratory and hemodynamic status. Prolonged prone ventilation improved oxygenation in the ARDS patients. Based on EIT measurements, the distribution of ventilation was homogenized and dorsal lung ventilation was significantly improved by PP administration, while the effect of PP on lung perfusion was relatively mild, with increased dorsal lung perfusion observed. The ventilation–perfusion matched region was found to increase and correlate with the increased PaO2/FiO2 by PP, which was attributed mainly to reduced shunt in the lung.ConclusionsProlonged prone ventilation increased dorsal ventilation and perfusion, which resulted in improved ventilation–perfusion matching and oxygenation.Trial registration: ClinicalTrials.gov, NCT04725227. Registered on 25 January 2021.

Non-invasive hemodynamic evaluation following TAVI for severe aortic stenosis

Abstract Funding Acknowledgements Type of funding sources: None. Background Various hemodynamic changes occur following Transcatheter aortic valve implantation (TAVI) that impact treatment decisions. NICaS, a noninvasive whole-body bio-impedance monitoring system to assess hemodynamics and fluid balance, was tested in patients with severe aortic stenosis (AS) before and after TAVI. Methods Between October 2019 and December 2020 all consecutive patients with severe AS undergoing TAVI were assessed by NICaS at several time points – 24 hours before (baseline) and after the procedure, at hospital discharge and at 30 days to 1 year follow-up. Excluded were patients undergoing TAVI due to reasons other than severe AS, patients under general anesthesia and those who died at the catheterization lab or immediately following the procedure. Results We performed hemodynamic analysis on 97 consecutive patients who underwent TAVI using either Medtronic Evolut R (54%), Edwards Sapien 3 (32%) or SYMETIS ACURATE neo (13%). Patients were more often women (54%) and had multiple comorbidities including hypertension (83%), dyslipidemia (79%), coronary artery disease (46%), and diabetes mellitus (37%). Compared to baseline NICaS measurements, we observed increases in systolic blood pressure (BP) and total peripheral resistance (TPR) within 24 hours following TAVI (systolic BP 132.5±22.3 mmHg at baseline versus 148.4±23.9 mmHg after TAVI, P&amp;lt;0.001; TPR 1754±520 versus 2094±752 dynes*s/cm5, respectively, P&amp;lt;0.001) while cardiac output (CO), cardiac index (CI) and stroke volume (SV) decreased (CO 4.2±1.2 versus 3.9±1.2 L/min, respectively, P=0.013; SV 62±15 versus 56±15.8 mL, P=0.002). However, opposite trends were demonstrated exclusively in patients with ejection fraction (EF) under 40%. At follow-up (median 59 days, IQR [39.5-91]) these hemodynamic measurements returned to values that were not statistically different from the baseline, despite a significant improvement in EF from baseline to follow-up (55.6±11.6 to 59.4±9.4%, P&amp;lt;0.001). Conclusion A unique pattern of short and longer term adaptive hemodynamic changes was demonstrated using the NICaS system among patients undergoing TAVI. These findings require validation and further research to their underlying mechanism if NICaS is to be used as a bedside monitoring tool to guide treatment decisions.

Lung Ultrasound in a Critically Ill Trauma Patient: A Case of Haemothorax Overlooked with Chest Radiograph and Computerised Tomography.

Critical care ultrasound has earned its place not just as a further investigation step but as a bedside physical assessment and monitoring tool. Its potential to become the twenty-first-century stethoscope has proved its accuracy by many protocols so far.

Optic nerve sheath diameter assessment by neurosonology: A review of methodologic discrepancies.

Reported cutoff values of the optic nerve sheath diameter (ONSD) for the diagnosis of elevated intracranial pressure (ICP) are inconsistent. This hampers ONSD as a possible noninvasive bedside monitoring tool for ICP. Because the influence of methodological differences on variations in cutoff values is unknown, we performed a narrative review to identify discrepancies in ONSD assessment methodologies and to investigate their effect on reported ONSD values. We used a structured and quantitative approach in which each ONSD methodology found in the reviewed articles was categorized based on the characteristic appearance of the ultrasound images and ultrasound marker placement. Subsequently, we investigated the influence of the different methodologies on ONSD values by organizing the ONSDs with respect to these categories. In a total of 63 eligible articles, we could determine the applied ONSD assessment methodology. Reported ultrasound images either showed the optic nerve and its sheath as a dark region with hyperechoic striped band at its edges or as a single dark region surrounded by lighter retrobulbar fat. Four different ultrasound marker positions were used to delineate the optic nerve sheath, which resulted in different ONSD values and more importantly, different sensitivities to changes in ICP. Based on our observations, we recommend to place ultrasound markers at the outer edges of the hyperechoic striped bands or at the transitions from the single dark region to the hyperechoic retrobulbar fat because these locations yielded the highest sensitivity of ONSD measurements for increased ICP.

Gray-scale ultrasound findings of hypoxic-ischemic injury in term infants.

Brain ultrasound has become a critical tool for bedside screening and monitoring of hypoxic-ischemic injury in infants. Transfontanellar ultrasound in infants allows delineation of anatomical structures of the brain and posterior fossa. The technique's low cost, lack of ionizing radiation and repeatability make it a popular alternative to magnetic resonance imaging. The published literature on interpreting hypoxic-ischemic injury on brain ultrasound is wide and varied, yet diagnostic challenges remain when detecting subtle or diffuse changes. This pictorial essay summarizes and illustrates the spectrum of sonographic findings of hypoxic-ischemic injuries in term infants.

A practical method for determining automated EEG interpretation software performance on continuous Video-EEG monitoring data

Despite evidence to suggest that as many as 30% of hospitalized patients with altered mental status may be having subclinical seizures for which treatment may improve patient outcomes, the adoption of continuous video electroencephalography (EEG) monitoring (cvEEG) into non-academic centers has remained slow. With the continued progress in EEG networking technology and telemedicine, the traditional barriers to the use of cvEEG in community hospitals may soon be removed. This will lead to significant increases in the volume of cvEEG data that needs to be reviewed. The application of computer analytics to automate the process of cvEEG review has been ongoing for many years. One solution has been the use of graphic trends to allow more rapid review and assessment of the content of the cvEEG data over long periods of time. However, high false positive rates, the lack of specificity, and the requirement for frequent review of the raw cvEEG data to confirm the results has limited the use of this modality as a bedside monitoring tool. Thus, the development of truly automated cvEEG readers will be needed. Here we address the challenges of assessing the performance of such automated readers using the traditional core measures of performance: sensitivity, specificity, false positive/negative rates and diagnostic accuracy, and introduce an alternative approach to measuring and assessing performance that focuses on agreement. Our work demonstrates that traditional approaches to objectively assess agreement and performance of automated readers are difficult to apply and may not provide accurate estimates of the real-world performance of computer analytic interpretations of cvEEG data. We introduce our “Pure Gold” approach to the assessment of automated cvEEG reading tools. This novel approach uses compiled EEG segments representing a single target pattern to measure true error rates for the automated reader, visual graphical representation of automated reader outputs for comparison to human reviews of the same data, and agreement comparisons with correction for human variation. We suggest our approach represents a better method for performance assessment than traditional metrics of sensitivity and specificity.

Abstract 14846: Artificial Intelligence and Clinical Stability After the Norwood Operation

Background: Postoperative management of the neonate following the Norwood operation is among the most complex and challenging in pediatric critical care. Artificial intelligence is poised to assist in management of this complex population. Methods: We developed a convolutional neural network (CNN) model trained on electrocardiogram (ECG) waveforms collected from 45 neonates after the Norwood procedure. Waveforms from the first two postoperative days (critical) and the day prior to transfer out of the ICU (stable) were used for training. The model was validated on 10 post-Norwood neonates. Models were compared to traditional machine learning algorithms on non-waveform data, heart rate variability, and then combined in a final model to optimize performance. Retrospective clinical observation scoring was completed for comparison. Results: The CNN model on 3-lead ECG yielded an area under the curve of the receiver operating characteristic (AUC-ROC) of 0.97 ( 0.02). The final model combining predictions from the CNN, random forest on vital signs, and logistic regression on pH, lactic acid, and base deficit values achieved 0.98 ( 0.02). Retrospective clinical observations agreed with the final model 78% of the time. Conclusions: Application of this novel combined machine learning model can accurately detect changes in clinical status as patients progress from critically ill to stable following the Norwood procedure, yielding impressive clinical insights from the ECG beyond what is currently possible. This work provides the basis for the development of a novel bedside monitoring tool and suggests new ways artificial intelligence may influence clinical care beyond predicting deterioration events.

Olfactory Testing in Temporal Lobe Epilepsy: a Systematic Review.

Olfactory testing is a potentially safe, cost-effective, bedside evaluation tool for diagnosis, monitoring, and risk assessment for surgery in temporal lobe epilepsy (TLE) patients, but testing methods and relevant olfactory domains are not standardized. We conducted a systematic review to evaluate olfactory tests in TLE and summarize the results of the literature. Olfactory tests varied significantly in odorant administration tools and devices, target odorants, evaluation timing, and grading scales. The Smell Threshold Test and University of Pennsylvania Smell Identification Test were the most validated single-domain tests for odor detection and odor identification, respectively. For multi-domain tests, Odor Memory/Discrimination Test and the Sniffin' Sticks test were the most validated. Results of olfactory tests in TLE are presented by domain. Rigorous validation, standardization, and comparative analysis of existing olfactory tests by domain is urgently needed to establish the utility and efficacy of olfactory testing in TLE.

Precision Medicine in Neonates: Future Perspectives for the Lung.

Bronchopulmonary dysplasia (BPD) is the most common complication of pre-term birth with long lasting sequelae. Since its first description more than 50 years ago, many large randomized controlled trials have been conducted, aiming to improve evidence-based knowledge on the optimal strategies to prevent and treat BPD. However, most of these intervention studies have been performed on a population level without regard for the variation in clinical and biological diversity (e.g., gestational age, ethnicity, gender, or disease progression) between patients that is driven by the complex interaction of genetic pre-disposition and environmental exposures. Nevertheless, clinicians provide daily care such as lung protective interventions on an individual basis every day despite the fact that research supporting individualized or precision medicine for monitoring or treating pre-term lungs is immature. This narrative review summarizes four potential developments in pulmonary research that might facilitate the process of individualizing lung protective interventions to prevent development of BPD. Electrical impedance tomography and electromyography of the diaphragm are bedside monitoring tools to assess regional changes in lung volume and ventilation and spontaneous breathing effort, respectively. These non-invasive tools allow a more individualized optimization of invasive and non-invasive respiratory support. Investigation of the genomic variation in caffeine metabolism in pre-term infants can be used to optimize and individualize caffeine dosing regimens. Finally, volatile organic compound analysis in exhaled breath might accurately predict BPD at an early stage of the disease, enabling clinicians to initiate preventive strategies for BPD on an individual basis. Before these suggested diagnostic or monitoring tools can be implemented in daily practice and improve individualized patient care, future research should address and overcome their technical difficulties, perform extensive external validation and show their additional value in preventing BPD.

Estimating regional pulmonary blood flow in EIT with regularized deconvolution with a Tikhonov regularization

Abstract Electrical Impedance Tomography (EIT) is a clinically used tool for bed-side monitoring of ventilation. Previous work also showed a high potential for lung perfusion monitoring with indicator-enhanced EIT. However, many research questions have yet to be answered before it can be broadly applied in clinical everyday life. The goal of this work is to evaluate a new method to improve EIT perfusion measurements. Pulmonary hemodynamic transfer functions were estimated using regularized deconvolution with Tikhonov regularization to estimate spatial perfusion parameters. The final comparison between EIT images and PET scans showed a median correlation of 0.897 for the images which were reconstructed using the regularized deconvolution. In comparison the previously used maximum slope method led to a median correlation of 0.868.

Bedside Sonographic Duplex Technique as a Monitoring Tool in Patients after Decompressive Craniectomy: A Single Centre Experience.

Background and objectives: Bedside sonographic duplex technique (SDT) may be used as an adjunct to cranial computed tomography (CCT) to monitor brain-injured patients after decompressive craniectomy (DC). The present study aimed to assess the value of SDT in repeated measurements of ventricle dimensions in patients after DC by comparing both techniques. Materials and Methods: Retrospective assessment of 20 consecutive patients after DC for refractory intracranial pressure (ICP) increase following subarachnoid hemorrhage (SAH), bleeding and trauma which were examined by SDT and CCT in the context of routine clinical practice. Whenever a repeated CCT was clinically indicated SDT examinations were performed within 24 hours and correlated via measurement of the dimensions of all four cerebral ventricles. Basal cerebral arteries including pathologies such as vasospasms were also evaluated in comparison to selected digital subtraction angiography (DSA). Results: Repeated measurements of all four ventricle diameters showed high correlation between CCT and SDT (right lateral r = 0.997, p < 0.001; left lateral r = 0.997, p < 0.001; third r = 0.991, p < 0.001, fourth ventricle r = 0.977, p < 0.001). SDT performed well in visualizing basal cerebral arteries including pathologies (e.g., vasospasms) as compared to DSA. Conclusions: Repeated SDT measurements of the dimensions of all four ventricles in patients after DC for refractory ICP increase delivered reproducible results comparable to CCT. SDT may be considered as a valuable bedside monitoring tool in patients after DC.

Implementation of amplitude-integrated electroencephalography in tertiary Canadian Neonatal Intensive Care Units—a longitudinal study

To investigate the implementation of amplitude-integrated electroencephalography (aEEG) as bedside monitoring tool of cerebral function in tertiary Canadian Neonatal Intensive Care Units (NICU) over the past decade. Longitudinal study consisting of online surveys of neonatologists on the use of aEEG in 2009 and 2018. The response rate to the survey was 72 of 149 (49%) in 2009 and 18 of 30 (60%) in 2018, respectively. aEEG has been implemented in almost all (2009: 62.5%; 2018: 94%) tertiary Canadian NICUs. Two-thirds (2009: 67%; 2018: 71%) of the respondents considered information from aEEG tracing helpful in clinical practice. The main indications for aEEG were term neonates with hypoxic ischemic encephalopathy (2009 and 2018: 76%) and seizure detection/surveillance (2009: 88%; 2018: 94%). Teaching on aEEG has been implemented for neonatologists (2018: 100%) and health care providers (2018: 50%) in tertiary Canadian NICUs but there is a lack of standardization of training. Use of aEEG in preterm neonates (2009: 37%, 2018: 33%) and application of aEEG in research (18% reported occasional use) is less common. aEEG is well established in tertiary Canadian NICUs to monitor cerebral function and detect seizure activity. There is a need to develop formalized aEEG training programs and methods to assess competence. Further implementation of aEEG in preterm neonates and research is desirable.

Electrical Impedance Tomography for Cardio-Pulmonary Monitoring.

Electrical impedance tomography (EIT) is a bedside monitoring tool that noninvasively visualizes local ventilation and arguably lung perfusion distribution. This article reviews and discusses both methodological and clinical aspects of thoracic EIT. Initially, investigators addressed the validation of EIT to measure regional ventilation. Current studies focus mainly on its clinical applications to quantify lung collapse, tidal recruitment, and lung overdistension to titrate positive end-expiratory pressure (PEEP) and tidal volume. In addition, EIT may help to detect pneumothorax. Recent studies evaluated EIT as a tool to measure regional lung perfusion. Indicator-free EIT measurements might be sufficient to continuously measure cardiac stroke volume. The use of a contrast agent such as saline might be required to assess regional lung perfusion. As a result, EIT-based monitoring of regional ventilation and lung perfusion may visualize local ventilation and perfusion matching, which can be helpful in the treatment of patients with acute respiratory distress syndrome (ARDS).

Combined vEEG and Cerebral Oximetry Results to Determine the Severity of Hypoxic–Ischemic Encephalopathy

AbstractThe objectives of the study were to evaluate the prognostic utility of bedside monitoring tools for hypoxic–ischemic encephalopathy (HIE) outcome and develop a prognostic predictive model. This retrospective study reviewed neonatal HIE treated with hypothermia between 2013 and 2016. Continuous video electroencephalography (vEEG) recordings scored for background electrocerebral activity, seizure, and sleep–wake cycles, and rSO2 data were stratified by magnetic resonance imaging (MRI) severity. The vEEG and rSO2 were combined in a predictive model. The analysis included 38 patients. The rSO2 was significantly higher in the severe group. vEEG showed early and persistent maximal suppression in the severe group. The predictive correlation of the rSO2 improves when combined with the vEEG.