Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Monitoring”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,297 records · Page 72Linked to original sources
PubMedDate not supplied

Application of transcutaneous blood carbon dioxide monitoring to the magnetic resonance imaging of rat.

A transcutaneous blood gas monitor is a non-invasive tool that is used clinically. Magnetic resonance imaging (MRI) of the rat has been performed for basic research of pathology and brain science. Non-invasive monitoring of blood gas is expected for such small animal experiments because of the need to minimize blood loss. We applied a commercially available transcutaneous blood gas monitor to rat experiments with MRI. The monitoring responses to rat arterial tension of carbon dioxide (paCO2) appeared to change exponentially with the time constant 1820 +/- 40 s, which was five times slower than that of man. The jump in paCO2, however, can be translated only by a differential slope of values monitored by transcutaneous measurement of carbon dioxide (tcpCO2) at the timing of paCO2 change without waiting for the saturated value of tcpCO2. The magnetic field of MRI did not affect blood gas monitoring and magnetic material in the blood gas sensor did not jeopardize the magnetic homogeneity of imaging. The transcutaneous blood gas monitor can be applied to MRI measurements with paCO2 jumps.

Animals↗
PubMed1997

Natural protection of spring and well drinking water against surface microbial contamination. II. Indicators and monitoring parameters for parasites.

Recent outbreaks of cryptosporidiosis and reports of other newly described para-sitic diseases associated with drinking water transmission prompted a reevaluation of source water monitoring criteria for public health protection. The field of microbial indicators was reviewed and each candidate sentinel evaluated in terms of its sensitivity, specificity, and technical feasibility. In addition, a clear distinction was made between source water monitoring and monitoring in the distribution system. Of all potential candidate microbial sentinels, Escherichia coli is deemed the most efficacious for public health protection. Based on a conservative estimate of its half-life in groundwater for 8 d, it is recommended that at least two samples be obtained during this half-life. In addition to E. coli, two water quality indicator sentinels, which are not necessarily direct public health threats, should also be monitored at the same frequency. These are the total coliform group and the enterococci. If E. coli is present in any source water sample, the borehole and any directly connected borehole should be embargoed. If either total coliforms or enterococci are detected, only that individual borehole should be taken off line and not used until the situation is remediated and the cause of the fecal contamination eliminated. Clostridium perfringens spores serve as a useful long-lived indicator. However, their perseverance in a sample should not be considered a direct public health threat because spores may far outlive pathogens. As a parasite indicator, C. perfringens should have the same importance as a positive coliform or enterococcus analysis. Coliphages do not yet fulfill enough of the criteria to be routinely employed. Biological monitoring should be coupled with physicochemical monitoring to establish a long-term history of the source. Because all natural waters vary in the amounts of heterotrophic plate count bacteria, test methods should be employed that are refractory to them. A combination of rigorous source protection plus extraordinary source monitoring serve as sufficient multiple barriers for parasite protection.

Animals↗
PubMed1987

Continuous monitoring of intracranial pressure with a miniaturized fiberoptic device.

A No. 4 French fiberoptic catheter initially developed as an intravascular pressure sensor was incorporated into a system to be used as an intracranial pressure (ICP) monitor. Initially, a series of acute and chronic animal experiments carried out in the rabbit and pig, respectively, demonstrated the reliability and safety of the device. Subsequently, this new monitor was compared to a concurrently functioning ICP monitor in 15 adult and five pediatric patients. This clinical experience also confirmed the safety, accuracy, and reliability of the device. Since these initial studies, this monitor has been used to routinely measure ICP in a large number of adult and pediatric patients. The monitor has functioned well, and there have been no complications related to its use except for an occasional problem with breakage of the optic fiber as a result of patient movement or nursing maneuvers, which has been easily corrected by replacement of the probe. As nursing personnel and ancillary services have become familiar with this new monitor, breakage has not been a problem. This new device can be placed into the ventricular system, the brain parenchyma, or the subdural space, and appears to offer substantial advantages over other monitors presently in use.

Adult↗
PubMed2003

Monitoring of brain tissue oxygenation during aneurysm surgery: prediction of procedure-related ischemic events.

OBJECT: The aim of this study was to evaluate the feasibility of monitoring brain tissue oxygenation (PO2) during aneurysm surgery for the detection of procedure-related ischemia. METHODS: Between 1997 and 1998, PO2 was monitored prospectively in a cohort of 40 patients (42 recordings) during aneurysm surgery in the anterior circulation within the vascular territory of the aneurysm-bearing artery. The position of the probe used to measure oxygenation levels was verified on computerized tomography (CT) scanning on the 1st postoperative day. Because of the mislocation of one probe and the malfunction of another, data from only 38 patients (40 recordings) were suitable for analysis. Relative changes from baseline to absolute nadir values of intraoperative PO2 were correlated with simultaneously recorded somatosensory evoked potentials (SSEPs), and cardiovascular and ventilatory parameters. The frequency of ischemic events was evaluated with the aid of CT on the 1st postoperative day as a substitute parameter for intraoperative ischemia. Clinical outcome was evaluated 30 days postoperatively based on the Glasgow Outcome Scale. Except for three, all patients underwent surgery for treatment of a symptomatic aneurysm. Mean baseline PO2 was 23.9 mm Hg (range 2-67.2 mm Hg) before clip application. A relative decrease in PO2 (20% decrease in value compared with baseline) occurred in 12 patients and was a sensitive indicator for the risk of ischemia during temporary arterial occlusion, but was less predictive of nonocclusive ischemia (sensitivity 0.5; positive predictive value [PPV] 0.42; p > 0.05). Results of receiver operating characteristic analysis demonstrated a postclipping PO2 nadir of 15 mm Hg as a dichotomizing threshold for the prediction of ischemia. This threshold rendered an improved sensitivity (0.9) and PPV (0.56) for procedure-related ischemia (p = 0.0003). The results of utility analysis revealed this monitoring parameter to be clinically diagnostic. Only PO2 monitoring, and not SSEP at the tibial nerve, was predictive of ischemia within the anterior cerebral artery territory. CONCLUSIONS: Using 15 mm Hg as a dichotomizing threshold, intraoperative PO2 monitoring enables one to identify patients at risk for procedure-related ischemia during aneurysm surgery and surpasses SSEP monitoring. This newly defined threshold based on intraoperative PO2 monitoring provides a basis for studies on treatments for procedure-related ischemia during aneurysm surgery.

Adult↗
PubMed2004

Monitoring of motor evoked potentials compared with somatosensory evoked potentials and microvascular Doppler ultrasonography in cerebral aneurysm surgery.

OBJECT: The aims of this study were to compare the efficiency of motor evoked potentials (MEPs), somatosensory evoked potentials (SSEPs), and microvascular Doppler ultrasonography (MDU) in the detection of impending motor impairment from subcortical ischemia in aneurysm surgery; to determine their sensitivity for specific intraoperative events; and to compare their impact on the surgical strategy used. METHODS: Motor evoked potentials, SSEPs, and MDU were monitored during 100 operations for 129 aneurysms in 95 patients. Intraoperative events, monitoring results, and clinical outcome were correlated in a prospective observational design. Motor evoked potentials indicated inadequate temporary clipping, inadvertent occlusion, inadequate retraction, vasospasm, or compromise to perforating vessels in 21 of 33 instances and deteriorated despite stable SSEPs in 18 cases. Microvascular Doppler ultrasonography revealed inadvertent vessel occlusion in eight of 10 cases and insufficient clipping in four of four cases. Stable evoked potentials (EPs) allowed safe, permanent vessel occlusion or narrowing despite reduced flow on MDU in five cases. Two patients sustained permanent and 10 showed transient new weakness, which had been detected by SSEPs in two of 12 patients and MEPs in 10 of 11 monitored cases. The surgical strategy was directly altered in 33 instances: by MEPs in 16, SSEPs in four, and MDU in 13. CONCLUSIONS: Monitoring of MEPs is superior to SSEP monitoring and MDU in detecting motor impairment, particularly that from subcortical ischemia. Microvascular Doppler ultrasonography is superior to EP monitoring in detecting inadvertent vessel occlusion, but cannot assess remote collateral flow. Motor evoked potentials are most sensitive to all other intraoperative conditions and have a direct influence on the course of surgery in the majority of events. A controlled study design is required to confirm the positive effect of monitoring on clinical outcome in aneurysm surgery.

Adult↗
PubMed1996

Intraoperative monitoring of microvascular decompression in hemifacial spasm.

The significance of intraoperative electrophysiologic monitoring during microvascular decompression was evaluated prospectively in 261 patients with the hemifacial spasm from 1985 to 1995. The patients were divided into a monitored group and a non-monitored group. Identification of the offending vessels was facilitated by the monitoring during the surgical procedure and the complication rate of the monitored group was significantly lower than that of the non-monitored group (p < 0.05). In addition, the abnormal muscle response continued to improve during the follow-up period, thus the electrophysiological status of the hemifacial spasm after the microvascular decompression improved significantly with time (p < 0.05). In conclusion, intraoperative monitoring is useful for identifying the exact offender among multiple vessels, and lowering the complication rate of the microvascular decompression for the hemifacial spasm.

Adult↗
PubMed1994

The nurse's role in continuous dysrhythmia monitoring.

One of the areas of clinical management where nurses have the most diagnostic influence is cardiac rhythm monitoring and dysrhythmia detection. The critical care nurse must recognize that continuous monitoring is a nursing responsibility, and competence in this skill must be assured. It is essential that nurses understand the significance of accurate electrode placement in obtaining a specific monitoring lead. In addition, the nurse must use current research in determining which monitoring lead is most appropriate for the patient requiring cardiac monitoring in the critical care environment. The author reviews the current research on continuous bedside monitoring and lead selection, examines why nurses continue to make less than optimal lead selection decisions, and offers recommendations to improve the consistency with which patients are accurately monitored.

Arrhythmias, Cardiac↗
PubMedDate not supplied

Hemodynamic monitoring in the care of the critically ill neuroscience patient.

Hemodynamic monitoring in the care of the critically ill neuroscience patient provides information that assists the clinician in minimizing secondary neuronal injury. Whereas no technology replaces the critical care nurse's physical assessment, hemodynamic and neurological monitoring provides additional data beyond what is possible with the clinical examination alone. If neurological technology, such as intracranial pressure monitoring, is not available, hemodynamic monitoring along with the neurological examination provides limited but useful information essential to minimizing secondary neuronal injury. The use of hemodynamic monitoring in critically ill neuroscience patients is best exemplified in the management of cerebral vasospasm after aneurysmal subarachnoid hemorrhage. Although improved outcomes have not been scientifically substantiated, multimodality monitoring of intracranial dynamics and systemic hemodynamics and manipulation of these parameters during hypertensive hypervolemic hemodilution therapy may lessen the incidence of cerebral infarction secondary to vasospasm. Monitoring systemic hemodynamics and intracranial dynamics simultaneously assists in prevention, prompt recognition, and effective treatment of neurological deterioration.

Brain Ischemia↗
PubMed1989

Home prothrombin time monitoring after the initiation of warfarin therapy. A randomized, prospective study.

STUDY OBJECTIVE: To evaluate the efficacy and accuracy of monitoring prothrombin times at home. DESIGN: Randomized, prospective cohort study. SETTING: Outpatients discharged from a university hospital or a community hospital. PATIENTS: Fifty patients started on warfarin for the first time who demonstrated an ability to use the monitor and who had not achieved a stable response to warfarin in the hospital. INTERVENTION: Oral anticoagulation therapy managed using a portable prothrombin time monitor compared with specialized anticoagulation clinic care. MEASUREMENTS AND MAIN RESULTS: In the 46 patients who completed the 8-week study, the median percentage of time that patients in the home-monitor group (n = 23) were within a range equal to the target prothrombin ratio +/- 0.3, but always above 1.25, was 93%, compared with 75% for patients in the clinic group (n = 23) (P = 0.003). There was no significant difference between groups in the percentage of time above the therapeutic range; however, the percentage of time that patients were subtherapeutic was significantly greater in the clinic group (P less than 0.001). There were no major thromboembolic or hemorrhagic complications in either group. Differences between home monitor measurements and corresponding clinical laboratory measurements using blood samples drawn within 4 hours of the home test were comparable to differences observed between measurements using two different clinical laboratory instruments. CONCLUSIONS: Use of a portable prothrombin time monitor by patients at home is feasible and provides accurate measurements. Patients doing home monitoring achieve superior anticoagulation control compared with those receiving standard anticoagulation clinic care.

Adult↗
PubMedDate not supplied

The design of pressure monitoring devices: Infection control considerations.

Reports of infections related to in-use contamination or incomplete sterilization of pressure monitoring devices have appeared infrequently. However, review of our experience with such infections suggests a need for the medical instrumentation industry to stress infection prevention in the design of monitoring devices. Notably, it will be important for the industry to: (a) design pressure monitoring devices that can be sterilized rapidly, efficiently, and easily between use in different patients, even during periods of peak monitoring use; (b) develop reliable and simple means for aseptically calibrating and setting up monitoring devices after sterilization; and (c) design simple monitoring systems that will be resistant to in-use contamination and that will allow patients' monitoring tubing and fluid to be replaced aseptically at regular intervals.

Cross Infection↗
PubMed1994

In vitro evaluation of continuous mixed venous oxygen saturation and hematocrit monitors.

Four venous hemoglobin oxygen saturation monitors, two of which provide hemoglobin monitoring, were evaluated and compared to a performance standard (control) during cardiopulmonary bypass (CPB). The CDI 100 Hematocrit/Saturation Monitor, CDI 400, Cobe Hematocrit/Saturation Monitor, and the Baxter Bentley OxySat values were compared to the Radiometer Copenhagen OSM3 Hemoximeter and the Damon International Equipment Company Microbore Centrifuge Hematocrit. The Bentley OxySat meter was found to be the most accurate venous oxygen saturation monitor, with the CDI 100 and the Cobe Hct/Sat monitors correlating closely with the control. Only the CDI 400 failed to correlate with the control. The hematocrit monitors, although useful as trending devices, demonstrated inaccuracies in measurements requiring further refinement.

Hematocrit↗
PubMedDate not supplied

New developments in perioperative cardiovascular monitoring.

Substantial technological progress has been made recently in the area of perioperative cardiovascular monitoring. Specialized monitoring may be performed for problems identified by preoperative evaluation. New technologies have been developed for monitoring the blood pressure continuously and non-invasively. Electrocardiographic monitoring of perioperative ischemia has been characterized. Newer techniques in echocardiography such as the use of contrast, and tissue characterization allowed improved monitoring of ischemia as well as ventricular function. Continuous monitoring of cardiac output can be performed by impedance cardiography and Doppler ultrasound and by continuous thermodilution. Improved rules for the differentiation of ventricular from supraventricular tachycardia have been developed. Detection of MI has been facilitated by new scintigraphic and enzymatic techniques. In critically ill patients, multi-system monitoring may be required to adequately assess the cardiovascular system.

Cardiovascular Diseases↗
PubMedDate not supplied

Technical aspects and clinical indications of 24-hour intragastric bile monitoring.

Bilitec 2000 is a new device which spectrophotometrically detects the presence of bilirubin in the refluxate. It is, up to date, the only method able to monitor for 24 hours the exposure time of esophageal and/or gastric mucosa to bilirubin-containing reflux. From the technical point of view, a particularly relevant aspect is the necessity of associating pH and Bilitec monitorings. The reason why is that, even in the stomach where Bilitec itself is adequate for assessing the exposure time to duodenogastric reflux, the damaging capability of the different components of reflux strictly depends upon pH. The most correct position inside the stomach for gastric monitoring is the 5 cm-below-the-LES-distal-border-position. The diet needs to be standardized in order to avoid false positive results due to the ingestion of foods with absorption close to bilirubin absorption. Ranges of normality will soon be available from a collaborative European Study. At variance with the indications for esophageal monitoring which are wide (the same as for pH-monitoring), indications for gastric Bilitec monitoring are represented only by severe dyspeptic symptoms possibly related to duodenogastric reflux. An antrum-confined C gastritis in the absence of history of consumption of gastro-lesive drugs strongly suggests the possibility of duodenogastric reflux. In this case, Bilitec monitoring can provide further evidence by measuring the time of exposure of the gastric mucosa to reflux.

Bile Reflux↗
PubMed1999

[What kind of monitoring of intracranial pressure].

Intracranial pressure monitoring is an essential element of severe head injury monitoring. In the Italian reality, this monitoring still has not become diffusely utilised. In this paper are analysed, using the available data obtained from the Neurolink database, the information from the more advanced Italian neurotrauma centres. Only 50% of the patients, in which monitoring is indicated, are monitored. Synthetically will be reviewed the indications to the monitoring, the advantages offers from such procedure, the modalities of monitoring considering also the economic impact and the risks legacies to the procedure.

Craniocerebral Trauma↗
PubMed1999

A complication of intraoperative facial nerve monitoring: facial skin burns.

OBJECTIVE: To report on three cases of severe facial skin burns resulting from intraoperative facial nerve monitoring in patients undergoing parotidectomies. STUDY DESIGN: This study is a retrospective case review. SETTING: A tertiary referral center. PATIENTS: This study includes three patients who underwent parotidectomies with concurrent facial nerve monitoring. RESULTS: Facial skin burns were proven to result from a technical defect of the intraoperative facial nerve monitoring device. Burns were sustained at electrode insertion sites and their extent was related to the duration of monitoring. The most probable explanation of these burns is electrolysis. CONCLUSIONS: Successful retracing of technical defaults with biomedical engineers at the device manufacturer have led to the upgrade of the facial nerve monitor apparatus. The benefits of facial nerve monitoring largely outweigh the fortuitous occurrence of skin burns reported in this study. Therefore, this complication should not represent a drawback to the use of facial nerve monitoring.

Adult↗
PubMed2000

[Home monitoring of infants at risk of sudden infant death: suggestions for reconsideration of current practice].

Considering the decreasing incidence of sudden infant death syndrome (SIDS) and the yet unproven efficacy of home monitoring, current indications for home monitoring should be reconsidered. Documented monitoring still appears to be necessary in infants with apparent life-threatening events (ALTE) and in siblings of two or more SIDS victims. Home monitoring is also indicated in infants on home oxygen/ventilation or with specific respiratory control disorders, but is usually not indicated in asymptomatic preterm infants or in those with a single SIDS sibling, a mother indulging in drug abuse, or increased parental anxiety. The risk of SIDS in these groups is lower than that in infants of mothers who are heavy smokers, who are nowhere regarded as candidates for home monitoring. If monitoring is considered necessary, new generation pulse oximeters with low false alarm rates are probably the safest technical option because they sound the alarm comparatively early, yet do not give too many false alarms. Home monitor recommendations should be revisited, taking the above issues into account.

Age Factors↗
PubMed2001

Bispectral index monitoring in sevoflurane and remifentanil anesthesia. Analysis of drugs management and immediate recovery.

BACKGROUND: Recent studies have suggested that electroencephalogram bispectral index (BIS) monitoring can improve recovery after anaesthesia and save money by shortening patients postoperative stay. The aim of the study is to evaluate the management of drugs and to measure immediate recovery after anaesthesia with or without BIS monitoring. METHODS: We studied 90 patients undergoing abdominal surgery randomly allocated to one of two groups of 45 each with or without BIS monitoring. Standard monitoring (EKG, arterial oxygen saturation and non-invasive blood pressure) was applied. All groups were monitored with BIS, using electrodes (Zipprep, Aspect Medical Systems) applied to the forehead. In the group 2 the BIS value was blinded to the anaesthesiologist. The BIS value was displayed using Spacelabs Medical BIS Ultraview Monitor. After obtaining baseline values for the BIS index (group 1) and haemodynamic data (all groups) anaesthesia was induced with a bolus dose of remifentanil and TPS, and vecuronium. The anaesthesia was maintained with Remifentanil and Sevoflurane. At standard times BIS, haemodynamic and respiratory parameters were recorded. Recovery times were measured by a study coordinator. Drug consumption was calculated. RESULTS: In group 1 the consumption of Sevoflurane decreased by 40 % while the consumption of remifentanil decreased by 10 % as compared to group 2. The use of vecuronium did not change in the 2 groups. In group 1 the time elapsed from cessation of anaesthetics to orientation decreased significantly. The difference was 5 min, from 11 to 6 min. CONCLUSIONS: BIS monitoring decrease both sevoflurane and remifentanil consumption, when compared to anaesthesia without BIS, with an immediate recovery after sevoflurane and remifentanil anaesthesia.

Adult↗
PubMedDate not supplied

Environmental monitoring of pesticides by immunoanalytical techniques: validation, current status, and future perspectives.

Reliable monitoring technology is an essential component of effective regulation and risk management of environmental contaminants such as pesticides. Most environmental monitoring and analysis is currently conducted using instrumental techniques such as gas-liquid chromatography (GLC) and liquid chromatography (LC). Immunoanalysis provides powerful monitoring techniques that have emerged in the last 3 decades. This paper shows they can deliver rapid, accurate, and relatively inexpensive analysis with high throughput and that have the capability to be field oriented. The technique is versatile in application and can be formatted to suit different purposes such as quantitative analysis or simple "yes/no" tests that are field-portable. While there is a range of opinion on the merits of immunoassays as an analytical tool for pesticides, we suggest that this technology is best considered as complementary to GLC and LC, extending the range of capability for field monitoring. Supporting this view, an increasing number of successful applications of immunoassays to monitoring have been reported in recent years. We also report here the implications of recent developments in the field of immunodiagnostics and their application to monitoring of environmental contaminants. We emphasise that, together with adequate validation by instrumental techniques, immunoassays provide monitoring services yielding realistic and comprehensive data for risk management, allowing decisions on appropriate action by various authorities to be made.

Animals↗