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At least 181 records · Page 10Linked to original sources

Physiologic and biochemical monitoring during hyperbaric oxygenation: a review.

Hyperbaric oxygenation (HBO2) is an important treatment given to various groups of patients exposed to pathologic situations (i.e., carbon monoxide exposure). Since many hyperbaric patients are critically ill and are being treated for life-threatening disorders, it is necessary to monitor various physiologic and biochemical parameters. This is a review of 193 publications covering a wide range of monitored parameters representing metabolic, hemodynamic, respiratory, electrical, and biochemical activities. The significance of monitoring the physiologic, medical, and specific oxygen toxicity effects during HBO2 exposure (MHBO2) is described and emphasized. Further development of new monitoring devices and technologies will enable the improvement of patient management during HBO2 treatment given under various medical conditions. This review also presents new ideas about possible future monitoring of brain function under HBO2 conditions in experimental animals as well as under clinical conditions.

Animals↗

+Gz-induced loss of consciousness and aircraft recovery.

Aircrew incapacitation resulting from very high onset sustained +Gz stress has resulted in significant losses of aircraft and aircrew. Enhanced protection and training toward prevention of +Gz-induced loss of consciousness (G-LOC) will continue to be vital. Techniques for reduction of the time of incapacitation, should G-LOC occur, must also be explored and developed. Current capability of aircraft autorecovery as demonstrated by the Advanced Fighter Technology Integration F-16 (AFTI/F-16) promises to enhance safety from the acute incapacitation resulting from G-LOC (and spatial disorientation). Physiologic monitoring for determining G-LOC has certain advantages especially in the aerial combat arena. The optimum physiologic monitoring technique would be direct determination of failure of brain cell function at the cellular or subcellular level. Complete investigation of G-LOC is necessary to understand the phenomenon and to develop methods for enhancing recognition and recovery. This paper discusses aircraft autorecovery technology and potential methods for physiologic monitoring of G-LOC. Integration of physiologic monitoring techniques into aircraft autorecovery systems requires a broad approach for optimal development.

Aerospace Medicine↗

Instrumentation for the remote monitoring of physiological and behavioral variables.

Few commercial products are available for investigators who wish to monitor multiple physiological and behavioral variables in unrestrained subjects. When telemetry is not practical, e.g., in studies of at-sea diving physiology, one of the only options is to design and build a custom data-logging instrument. This paper describes how a data logger was developed for the successful long-term monitoring of dive depth, swim speed, heart rate, water temperature, and multiple body temperatures from free-ranging northern elephant seals. The task was facilitated by using a commercially available single-board computer designed specifically for portable multichannel data acquisition and, where possible, off-the-shelf sensors/transducers available with integrated signal-conditioning circuits. A smaller data logger for monitoring the electrocardiogram, body temperature, and dive behavior of double-crested cormorants is also described to illustrate the flexibility and simplicity of this approach. Although it is customized for diving animals, with incorporation of the appropriate sensors the basic design should be applicable to studies of comparative, environmental, or exercise physiology involving most medium-to-large animals, including humans.

Animals↗

Automated acquisition system for routine, noninvasive monitoring of physiological data.

A fully automated, noninvasive data-acquisition system was developed to permit long-term measurement of physiological functions at home, without disturbing subjects' normal routines. The system consists of unconstrained monitors built into furnishings and structures in a home environment. An electrocardiographic (ECG) monitor in the bathtub measures heart function during bathing, a temperature monitor in the bed measures body temperature, and a weight monitor built into the toilet serves as a scale to record weight. All three monitors are connected to one computer and function with data-acquisition programs and a data format rule. The unconstrained physiological parameter monitors and fully automated measurement procedures collect data noninvasively without the subject's awareness. The system was tested for 1 week by a healthy male subject, aged 28, in laboratory-based facilities.

Activities of Daily Living↗

Pre-discharge "car seat challenge" for preventing morbidity and mortality in preterm infants.

BACKGROUND: Physiological monitoring studies indicate that some preterm infants experience episodes of oxygen desaturation, apnoea, or bradycardia when seated in standard car safety seats. The American Academy of Pediatrics recommends that all preterm infants should be assessed for cardiorespiratory stability in their car seat prior to discharge - the "car seat challenge". We aimed to assess the evidence to support this practice, specifically to determine whether the use of the car seat challenge prevents morbidity and mortality in preterm infants. OBJECTIVES: To assess the available evidence from randomised controlled trials that pre-discharge cardiorespiratory monitoring in a car safety seat prevents morbidity and mortality in preterm infants. SEARCH STRATEGY: We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2005), MEDLINE (1966 - September 2005), EMBASE (1980 - September 2005), CINAHL (1982 - September 2005), conference proceedings, and previous reviews. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials that compared pre-discharge cardiorespiratory monitoring in a car seat versus no monitoring in preterm infants in the week prior to planned discharge from hospital. DATA COLLECTION AND ANALYSIS: The standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two review authors, and synthesis of data using relative risk, risk difference and weighted mean difference. MAIN RESULTS: We did not find any randomised controlled trials that fulfilled the eligibility criteria. AUTHORS' CONCLUSIONS: It is unclear whether undertaking a pre-discharge car seat challenge is beneficial or harmful to preterm infants. Further studies are needed to determine whether the car seat challenge accurately predicts the risk of clinically significant adverse events in preterm infants travelling in car seats. If this is shown to be the case then a large randomised controlled trial is needed to provide an unbiased assessment of its utility in pre-discharge assessment.

Humans↗

Methodological considerations in rat brain BOLD contrast pharmacological MRI.

RATIONALE AND OBJECTIVES: Blood oxygen level dependent (BOLD) contrast pharmacological magnetic resonance imaging (phMRI) is an increasingly popular technique that allows the non-invasive investigation of spatial and temporal changes in rat brain function in response to pharmacological stimulation in vivo. Rat brain BOLD contrast phMRI is, at present, established in few neuropharmacological laboratories, and various issues associated with the technique require attention. The present review is primarily aimed at psychopharmacologists with no previous experience of phMRI, who are interested in the practical aspects that phMRI studies entail. RESULTS AND DISCUSSION: Experimental and analytical considerations, including anaesthesia, physiological monitoring, drug dose and delivery, scanning protocols, statistical approaches and the interpretation of phMRI data, are discussed.

Anesthesia↗

The BrainIT group: concept and core dataset definition.

INTRODUCTION: An open collaborative international network has been established which aims to improve inter-centre standards for collection of high-resolution, neurointensive care data on patients with traumatic brain injury. The group is also working towards the creation of an open access, detailed and validated database that will be useful for post-hoc hypothesis testing. In Part A, the underlying concept, the group coordination structure, membership guidelines and database access and publication criteria are described. Secondly, in part B, we describe a set of meetings funded by the EEC that allowed us to define a "Core Dataset" and we present the results of a feasibility exercise for collection of this core dataset. METHODS: Four group meetings funded by the EEC have enabled definition of a "Core Dataset" to be collected from all centres regardless of specific project aim. A paper based pilot collection of data was conducted to determine the feasibility for collection of the core dataset. Specially designed forms to collect the core dataset demographic and clinical information as well as sample the time-series data elements were distributed by both email and standard mail to 22 BrainIT centres. A deadline of two months was set to receive completed forms back from centres. A pilot data collection of minute by minute physiological monitoring data was also performed. FINDINGS: A core-dataset was defined and can be downloaded from the BrainIT web-site (go to "Core dataset" link at: www.brainit.org). Eighteen centres (82%) returned completed forms by the set deadline. Overall the feasibility for collection of the core data elements was high with only 10 of the 64 questions (16%) showing missing data. Of those 10 fields with missing data, the average number of centres not responding was 12% and the median 6%. An SQL database to hold the data has been designed and is being tested. Software tools for collection of the core dataset have been developed. Ethics approval has been granted for collection of multi-centre data as part of a pilot data collection study. INTERPRETATION: The BrainIT network provides a more standardised and higher resolution data collection mechanism for research groups, organisations and the device industry to conduct multi-centre trials of new health care technology in patients with traumatic brain injury.

Brain Injuries↗

Basic techniques of cardiac MR.

Cardiovascular magnetic resonance (CMR) can be performed routinely due to the continued developments of MR systems, coil technology and sequence techniques, which have considerably shortened acquisition times. Techniques for the physiological monitoring of the patients are available for example, to synchronize the data acquisition with the individual heart cycle. The development of vectorcardiography-based (VCG) triggering improves the detection of the R-waves and reduces the number of misinterpreted ECG events to a minimum. Depending on the clinical question, spin or gradient echo-based sequences with different k-space filling methods are used in CMR. For spin preparation, inversion or saturation recovery techniques are used to suppress the signal of a specific tissue, or to maximize the T1 contrast between different soft tissues. Parallel acquisition methods (PAT) are available to speed up CMR imaging even further.

Contrast Media↗

Physiologic trend detection and artifact rejection: a parallel implementation of a multi-state Kalman filtering algorithm.

Using a parallel implementation of the multi-state Kalman filtering algorithm, we have developed an accurate method of reliably detecting and identifying trends, abrupt changes, and artifacts from multiple physiologic data streams in real-time. The Kalman filter algorithm was implemented within an innovative software architecture for parallel computation: a parallel process trellis. Examples, processed in real-time, of both simulated and actual data serve to illustrate the potential value of the Kalman filter as a tool in physiologic monitoring.

Algorithms↗

Physiologic changes during colonoscopy.

We prospectively evaluated multiple physiologic parameters in 104 consecutive unselected patients undergoing elective colonoscopy. Changes observed during colonoscopy were then correlated with the type of anesthesia and level of sedation, position of the endoscope and presence of looping, existence of comorbid medical conditions, concomitant medication usage, and the occurrence of endoscopy induced pain. Clinically important changes in O2 saturation (54%) and in blood pressure (44%) were most frequently noted. Less frequent were changes in pulse (15%) or respiratory rate (4%). These clinically significant changes were associated with induction of anesthesia or endoscope looping and pain in 58 to 62% of the patients. In the remainder of patients, no obvious factor was associated with the observed alterations in physiologic parameters. There was no correlation with presence of comorbid medical conditions, use of concurrent medication, dose of anesthesia, level of sedation, and/or colon segment reached by the endoscope. Although there was no apparent morbidity associated with the induced changes in physiologic parameters, these data suggest that certain patients may be at increased risk of procedure-related morbidity and support the need for physiologic monitoring in high-risk patients.

Adult↗

Nonlinearity of heart rate in the neonate.

The relationship between heart rate variability and level of illness was examined. Fifteen patients (10 male and 5 female), gestational ages 25 to 42 weeks, postnatal ages 1 to 42 days, birthweights 545 to 4375 g receiving care in the neonatal intensive care nursery were randomly selected. Data from each infant was transferred from the bedside physiologic monitor to a microcomputer for analysis. A severity of illness index (the Children's Hospital Illness Score [CHILLS]) correlated with heart rate variability. Four patterns of heart rate variability were identified: (1) infants whose CHILLS score indicated that they were cardiovascularly normal demonstrated a modest amount of variability; (2) infants with a CHILLS score indicating a moderate amount of illness had heart rates and heart rate variability greater than the normal infants; (3) three infants exhibited bimodality (period doubling) in their heart rates; each of these infants had a CHILLS score that indicated that they were less ill than the most critically ill patients, but sicker than those moderately ill infants without period doubling; and (4) heart rate decreased in the most critically ill infants identified by the CHILLS, but it remained above the heart rate of a healthy newborn; heart rate variability collapsed below that of a healthy newborn. Our data suggest that the variability of heart rate may increase as an infant becomes sicker. When the infant becomes critically ill and unstable, heart rate variability is less than the normal infant. Nonlinear dynamics theory may be a potential model for fitting the data.

Birth Weight↗

Major hepatic resection using vascular isolation and hypothermic perfusion.

The technique and results of 29 major hepatic resections using the method of complete vascular isolation and hypothermic perfusion of the liver are reported. The method enables the surgeon to perform otherwise difficult or impossible resections through chilled bloodless hepatic parenchyma. Major intrahepatic vascular structures can thus be recognized and controlled readily under clear vision. Direct neoplastic involvement of, or tumor thrombi in the portal vein, hepatic vein or vena cava, can be successfully dealt with by appropriate surgical measures. The operative mortality was 10.3% for this series which included many tumors previously deemed unresectable. The technical detail and intraoperative physiologic monitoring crucial to success in the use of the method are described. It is hoped that with the widened scope of resectability afforded by this technique, and the use of adjuvant chemotherapy, the currently experienced low cure rates for hepatic cancer can be improved.

Cyclophosphamide↗

The contribution of the dorsal and ventral roots of the tibial nerve in the propagation of the spinal somatosensory evoked potential in cats.

This study employed selective unilateral dorsal and ventral rhizotomy to examine the contribution of both the dorsal and ventral roots of the tibial nerve in the induction of the spinal somatosensory evoked potential (SSEP) in the cat. The spinal roots of origin of the tibial nerve in the cat were determined by retrograde transport of horseradish peroxidase (HRP). Spinal roots L6, L7, and S1 were found to give rise to the cat tibial nerve. Physiologic monitoring showed that the dorsal roots at these levels primarily contribute to the induction of the SSEP, but the ventral roots also make a small contribution. Because bilateral tibial nerve stimulation was found to mask a root injury on one side, we recommend sequential unilateral peripheral nerve stimulation when using SSEP during operations on the spine.

Animals↗

Indirect calorimetry: a trend toward continuous metabolic assessment.

Physiologic monitoring of the patient's metabolic response to illness and nutritional needs has been available for many decades. Traditional methods for estimating and intermittently assessing the patient's metabolic status provide incomplete and often misleading information. The measurement oxygen consumption (VO2) and carbon dioxide production (VCO2) for assessment of the critically ill patient's metabolic status has been underutilized partly because of the limitations of available technologies. Recent advances in gas exchange technologies have made VO2 and VCO2 assessment readily available at the bedside on a continuous basis. This article provides a clinical review of specific current literature related to indirect calorimetry. A synthesis of the data supports the use of gas exchange measurements of VO2 and VCO2 for serial assessment of metabolic changes and for monitoring of the patient's nutritional status. Furthermore, a multidisciplinary approach to metabolic monitoring and nutritional assessment provides a cost-efficient means of patient care, which, when properly implemented, improves patient outcomes.

Calorimetry, Indirect↗

A method for identifying mechanisms of neurologic injury from cardiac surgery.

BACKGROUND: A method for linking discrete surgical and perfusion-related processes of care with cerebral emboli, cerebral oxyhemoglobin desaturation, and hemodynamic changes may offer opportunities for reducing overall neurologic injury for patients undergoing cardiac surgery. METHODS: An intensive intraoperative neurologic and physiologic monitoring approach was developed and implemented. Mechanisms likely to produce embolic (cerebral emboli), hypoperfusion (oxyhemoglobin desaturation), and hypotensive (hemodynamic changes) neurologic injuries were monitored and synchronized with the occurrence of surgical and perfusion clinical events/techniques using a case video. RESULTS: The system was tested among 32 cardiac surgery patients. Emboli were measured in the cerebral arteries and outflow of the cardiopulmonary bypass circuit among nearly 75% and 85% of patients, respectively. Oxyhemoglobin desaturation was measured among nearly 70% of patients. Hemodynamic information was recorded in 100% of patients. CONCLUSIONS: We developed and successfully implemented a method for detailed real-time associations between processes of clinical care and precursors of neurologic injury. Knowledge of this linkage will result in the redesign of clinical care to reduce a patient's risk of neurologic injury.

Cardiac Surgical Procedures↗

Alarm-enhancement systems for ventilators.

Ventilator alarms can be crucial for safeguarding the health and even the lives of patients. Therefore, it's vital that they--like other critical alarms--be readily detected in even the busiest, noisiest hospital departments. One way to make sure that this happens is to use alarm-enhancement systems, which communicate ventilator alarms to locations where they are more likely to be detected by caregivers. There are four basic categories of ventilator alarm enhancements: (1) interfacing ventilators with networked physiologic monitors, (2) incorporating commercially available systems for centralized remote monitoring of ventilator alarms, (3) interfacing ventilators with nurse call systems, and (4) utilizing remote annunciators for ventilator alarms. These options range widely in complexity, cost, and the types of care settings for which they're likely to be suitable. In this article, we describe the ventilator alarm-enhancement systems that are currently on the market. We highlight their pluses and minuses based on information we have gained from product literature, through conversations with suppliers, and, where possible, through discussions with users. We also provide guidance to facilities on how to choose among the various options and products available.

Decision Making, Organizational↗

Potential impact of advanced clinical information technology on healthcare in 2015.

Clinical information technologies now sporadically available will soon be in routine clinical use, bringing many changes to healthcare. For example, 1) The next generation Internet; 2) Real-time clinical decision support systems; 3) Off-line, population-based systems; 4) Large, integrated, individual patient-level phenotypic and genotypic databases with intelligent data mining capabilities; 5) Wireless, invasive and non-invasive physiologic monitoring devices; 6) Natural Language Processing (NLP) systems; and 7) Mathematical models of complex biological systems have the potential to impact significantly the future healthcare delivery system. While new information management and communication techniques and technologies will reduce many of the inefficiencies and inaccuracies of our present systems, there will be an equal, and potentially far more dangerous, set of unintended consequences. Informatics investigators and health system administrators must focus on the study of what is working and what is not, as well as, on development and testing of the new clinical information management and communication technologies, if we are to be ready for the future.

Databases as Topic↗

Health. Care. Anywhere. Today.

What if clinical quality medical equipment were available to every consumer in a form factor that was inexpensive, accurate, and easy to use? What if this equipment provided information that previously was un-measurable or very difficult to measure? What if the physiological state of individuals, at resolutions measured in thousandths of a second instead of in visits per year, could be measured easily, making it possible to ascertain caloric intake and expenditure, patterns of sleep, contextual activities such as working-out and driving, even parameters of mental state and health. What aspect of healthcare would not change? We present a system that is available today that enables this vision. This award-winning multi-channel wearable physiological monitor has enabled the collection of more than 90 million minutes of data in natural settings from thousands of subjects engaged in diverse activities. Data modeling efforts are resulting in applications that present meaningful and actionable information in real-time to users and their designated collaborators (physicians, family members, counselors, coaches, etc.) We describe the SenseWear system, its design, and a summary of validation studies, current commercial applications, and ongoing research. This discussion will show how the convergence of design for wearability, advances in machine learning, and improvements in wireless technology will manifest the future of health care as personal, ubiquitous, and collaborative.

Clothing↗