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 667 records · Page 37Linked to original sources

Acoustic neuroma surgery: use of cochlear nerve action potential monitoring for hearing preservation.

OBJECTIVES: To compare the hearing preservation results obtained with use of two intraoperative eighth nerve monitoring methods, cochlear nerve action potential (CNAP) and auditory brainstem response (ABR), during complete acoustic neuroma (AN) resection. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS: Thirty-three consecutive patients who underwent hearing preservation AN surgery. INTERVENTIONS: Intraoperative monitoring by CNAP and/or ABR during AN resection. MAIN OUTCOME MEASURE: Postoperative hearing. Hearing preservation was considered achieved for pure-tone average < or =50 dB and speech discrimination > or =50%. RESULTS: Thirty-two patients met inclusion criteria for the study. Monitoring was successfully performed in 23 of 25 patients (92%) who underwent attempted CNAP monitoring and 13 of 27 (48%) who underwent attempted ABR monitoring. When tumor size was < or =20 mm in greatest dimension, hearing preservation was achieved in 12 of 18 patients (67%) monitored with CNAP, versus 2 of 8 patients (25%) not monitored with CNAP (p = 0.05). Monitoring by ABR did not improve hearing preservation rates compared with those not monitored with ABR (40% vs. 63%). At the completion of surgery, the presence or absence of CNAP predicted the presence or absence of hearing preservation in 18 of 23 cases (p = 0.01), while ABR successfully predicted hearing results in 10 of 13 cases (p = 0.05). CONCLUSIONS: When CNAP and ABR monitoring techniques during AN surgery were compared, CNAP was more frequently obtainable. Monitoring by CNAP was significantly associated with a higher chance of hearing preservation. Monitoring by ABR did not have a positive influence on hearing preservation results. Both ABR and CNAP were useful for predicting postoperative hearing.

Adult↗

Self-monitoring in Type 2 diabetes mellitus: a meta-analysis.

AIMS: Self-monitoring of blood or urine glucose is widely used by subjects with Type 2 diabetes mellitus. This study evaluated the effectiveness of the technique at improving blood glucose control through a systematic review and meta-analysis. METHODS: Randomized controlled trials were identified that compared the effects of blood or urine glucose monitoring with no self-monitoring, or blood glucose self-monitoring with urine glucose self-monitoring, on glycated haemoglobin as primary outcome in Type 2 diabetes. RESULTS: Eight reports were identified. These were rated for quality and data were abstracted. The mean (SD) quality score was 15.0 (1.69) on a scale ranging from 0 to 28. No study had sufficient power to detect differences in glycated haemoglobin (GHb) of less than 0.5%. One study was excluded because it was a cluster randomized trial of a complex intervention and one because fructosamine was used as the outcome measure. A meta-analysis was performed using data from four studies that compared blood or urine monitoring with no regular monitoring. The estimated reduction in GHb from monitoring was -0.25% (95% confidence interval -0.61 to 0.10%). Three studies that compared blood glucose monitoring with urine glucose monitoring were also combined. The estimated reduction in GHb from monitoring blood glucose rather than urine glucose was -0.03% (-0.52 to 0.47%). CONCLUSIONS: The results do not provide evidence for clinical effectiveness of an item of care with appreciable costs. Further work is needed to evaluate self-monitoring so that resources for diabetes care can be used more efficiently.

Blood Glucose Self-Monitoring↗

Effect of auditory evoked potential index monitoring on anesthetic drug requirements and recovery profile after laparoscopic surgery: a clinical utility study.

BACKGROUND: The auditory evoked potential (AEP) monitor provides an electroencephalogram-derived index (AAI) that has been reported to correlate with the central nervous system depressant effects of anesthetic drugs. This clinical utility study was designed to test the hypothesis that AAI-guided administration of the maintenance anesthetics and analgesics would improve their titration and thereby provide a faster recovery from general anesthesia. METHODS: Seventy consenting patients undergoing elective general surgery procedures were randomly assigned to either a control (standard clinical practice) or AEP-monitored group. Although the AEP monitor was connected to all patients, the information from the monitor was only made available to the anesthesiologists assigned to patients in the AEP-monitored group. In the AEP-monitored group, the inspired desflurane concentration was titrated to maintain an AAI value of 15-20. In the control group, the inspired desflurane concentration was varied based on standard clinical signs. The AAI values and hemodynamic variables, as well as end-tidal desflurane concentrations, were recorded at 3- to 5-min intervals. The recovery times to achieve a White fast-track score greater than 12 and an Aldrete score of 10, as well as the actual duration of the PACU stay, were evaluated at 5- to 10-min intervals. Patient satisfaction with recovery from anesthesia was assessed using a 100-point verbal rating scale at 24 h after surgery. RESULTS: The average intraoperative AAI value in the AEP-monitored group was significantly higher than in the control group (16 +/- 5 vs. 11 +/- 8, P < 0.05). Use of the AEP monitor reduced the desflurane requirement by 26% compared to the control group (P < 0.01). In addition, the AEP-monitored group received less intraoperative fentanyl (270 +/- 120 vs. 390 +/- 203 microg, P < 0.05) and more rapidly achieved fast-track eligibility (29 +/- 19 vs. 56 +/- 41 min, P < 0.05). The time required to achieve an Aldrete score of 10 (60 +/- 31 vs. 98 +/- 55 min) and the duration of stay in the recovery room (78 +/- 32 vs. 106 +/- 54 min) were also significantly reduced in the AEP-monitored (vs. control) group (P < 0.05). CONCLUSION: Use of AEP monitoring as an adjunct to standard clinical monitors improved titration of anesthetic drugs, thereby facilitating the early recovery process after laparoscopic surgery.

Adult↗

End-tidal carbon dioxide monitoring stabilized hemodynamic changes during ECT.

Accumulation of carbon dioxide (CO2) can disturb systemic and cerebral hemodynamics in patients receiving electroconvulsive therapy (ECT). The purpose of this study was to identify the effects of end-tidal CO2 monitoring on hemodynamic changes in patients who received ECT under propofol anesthesia. ECT was prescribed to 40 patients under propofol anesthesia. Ventilation was assisted using a face mask and 100% oxygen, with or without end-tidal CO2 monitoring. Heart rate was significantly increased in patients without end-tidal CO2 monitoring at 1 to 5 minutes after electrical stimulation (p < 0.01). Mean arterial blood pressure and middle cerebral artery blood flow velocity in the group without end-tidal CO2 monitoring were significantly larger than the values in the group with the monitor at 1 to 5 minutes after electrical stimulation. Arterial CO2 tension in the group without end-tidal CO2 monitoring was larger than the value in the group with the monitoring at 1 minute (45+/-5 mm Hg with the monitor and 56+/-8 without the monitor) and 5 minutes (37+/-4 mm Hg with the monitor and 51+/-8 without the monitor) after electrical stimulation (p < 0.01). Application of end-tidal CO2 monitoring is considered beneficial for safe and effective anesthesia management of patients undergoing ECT, especially patients with an intracranial disorder or ischemic heart disease.

Adult↗

Self monitoring of glucose by people with diabetes: evidence based practice.

The inappropriate use of self monitoring of glucose is wasteful of NHS resources and can cause psychological harm. Although a few patients find that self monitoring enables them to understand and take control of their diabetes, many people with diabetes are performing inaccurate or unnecessary tests. There is no convincing evidence that self monitoring improves glycaemic control, nor that blood testing is necessarily better than urine testing. It may be appropriate for some patients not to monitor their own glucose but to rely instead on regular laboratory estimations of glycaemic control. Glucose self monitoring should be performed only when it serves an identified purpose. It is widely assumed that glucose self monitoring, preferably of blood glucose concentrations, is desirable or even essential for everyone with diabetes. It is common for patients who have previously tested their urine, or have done no glucose monitoring at home, to be taught to measure their blood glucose when they are admitted to hospital. In the community too, patients are often encouraged to monitor their blood glucose, and newly diagnosed patients of all ages are usually taught to measure their blood glucose concentrations. Self monitoring can sometimes be useful, but evidence is mounting that its indiscriminate use is of questionable value. In 1995, Pounds 42.6 million was spent on home monitoring of glucose in the United Kingdom (Intercontinental Medical Statistics, personal communication). Is this enormous cost justified? Is blood testing necessarily better than urine testing? Is glucose self monitoring always necessary, or is it sometimes a waste of time and money? Are recommendations for self monitoring based on sound evidence?

Blood Glucose↗

Results and complications of intracranial pressure monitoring in 303 children.

303 consecutive children who had insertion of an intracranial pressure (ICP) monitor for various reasons were reviewed to determine clinical value and complications rate of ICP monitoring in this age group. 286 patients had a Camino fiberoptic monitor. Of the remaining cases, 9 had a ventricular catheter, 7 had an extradural Gaeltec monitor, and 1 had a subdural feeding tube. The reasons for monitoring the ICP were: trauma in 132 children, postoperative monitoring after tumor surgery in 91, head injury due to child abuse in 30, severe medical conditions such as meningitis, encephalitis, and near-drowning in 30, intracranial hemorrhage in 15, and hydrocephalus in 5 children. The median age at insertion was 6 years (range from 1 month to 17 years), and the median Glasgow coma score before insertion was 7. Median duration of monitoring was 3 days, and 35 children (10%) had surgical procedures performed for raised ICP detected by monitoring. 238 (78%) had nonsurgical measures to control raised ICP. 6 (15%) of 40 children with an initial ICP > 50 mm Hg made a good recovery, but there were no survivors among 37 children who had an ICP consistently > 60 mm Hg and only 1 disabled survivor among 42 children with an ICP consistently > 50 mm Hg. The outcome in all 303 children correlated with averaged readings of ICP over 24 h and initial Glasgow coma score, but did not correlate with initial ICP measurements. Complications of monitoring were few and consisted of infection in 1 (0.3%) child, intracranial hemorrhage in 1 (0.3%) who had low platelet counts, displacement of monitor in 3 (1%), and malfunction of monitor in 8 (2.6%) children. We conclude that ICP monitoring in the pediatric age group substantially influences our clinical management of unconscious children and is safe.

Adolescent↗

[Apnea states in infants, anxiety of parents and pediatricians, and home monitoring of respiration in children].

In order to determine parental reasons of the use of home apnea/respiration monitors and to estimate the grounds of these decisions correspondence contact was achieved with the parents of 71 infants monitored by means of the APNEAL-1 device. Filled up questionnaires were the source of data regarding the families (structure, health practices, mothers' age and education, course of pregnancy and delivery), monitored infants (birth weight, Apgar score, apnea events) and the reasons of monitoring. Also opinions concerning monitor usefulness and performance were gathered. The majority of our families (> 97%) consisted of both parents, their socio-economic status was medium (52.11%) or good (46.48%) and they were residents of cities (88.73%). Cigarette smoking was present in 22 families (31%) with 13 smoking mothers (18.31%). Mothers' mean age was 29.11 years (SD 4.84), 45% of them had high school education and 36.62%-university education. As many as 45% of the pregnancies had a pathological course and 34.3% were terminated by a preterm delivery. Mean birth weight of monitored children was 2914.93 g (SD 971.4), mean Apgar score was 8.31 (SD 2.46). More than 60% of children were breast fed during the first six months of life, and 30% of them--during first year of life. Bed sharing was reported in only 8% of children. Apnea episodes were observed in 30 infants (42.25 of whole group), in 20 of them only during the neonatal period. More apnea episodes were present in premature infants (48% of premature versus 30% of full term infants). Only 12 children (16.9% of whole group) manifested apnea events during the monitoring period. However, almost all the parents (97%) had a high opinion of the role played by the monitor (mean monitoring time 7.12 months, SD 4.44). In 27 families (38%) a cause of monitoring was a preceeding apnea event. The decision of remaining parents was based exclusively on fear. This fear was justified only in a small number of families (previous SIDS victim, GER). Numerous children were monitored solely on the basis of information of apnea existence in children. Such a difficult to accept monitoring reason probably has its source in inappropriate family health education.

Adult↗

[Assessment of exposure to extremely low frequency magnetic field emitted from monitors].

OBJECTIVES: To investigate intensity of extremely low frequency magnetic field (ELFMF) emitted from cathode-ray tubes (CRT) of monitors in various directions and to find ways to avoid its influence. METHODS: Two hundred CRT monitors and 10 monitors with liquid-crystal display (LCD) were selected. Their ELFMF was detected for three times in front of the monitor at an interval of every 5 cm from 0 cm to 50 cm, as well as at various directions from the monitor. RESULTS: Intensity of ELFMF significantly attenuated at regular operating position (30 - 40 cm) from 0 cm to 50 cm in front of both 38 cm and 43 cm CRT monitors (P < 0.05). Intensity exceeded 0.4 microT both within 15 cm and 10 cm in front of 38 cm and 43 cm monitors. The highest intensity was found at the upright top position of both kinds of monitors, 9.54 microT for 38 cm monitor and 6.38 microT for 43 cm one, respectively. CONCLUSIONS: It is suggested to keep away from monitor screen as possible when operating a computer, to reduce unnecessary operation in front of a monitor screen, and to shorten operating time. To avoid more hazards from interactive interference between computers, it is necessary to increase distance between monitors.

Computers↗

[Clinical significance of home blood pressure monitoring and its application to daily clinical practice].

Seven million home blood pressure (HBP) monitors are manufactured annually and a total of more than 30 million monitors have been sold in Japan. HBP monitoring is regarded as clinically useful according to various overseas guidelines. The criteria for the diagnosis of hypertension based on HBP monitoring are specified by the Japanese Society of Hypertension (JSH) because of its excellent prognostic value, and it was also assessed as clinically useful in the 2004 JSH hypertension treatment guidelines (JSH 2004) released last autumn. Thus, HBP monitoring is becoming increasingly important. HBP monitoring boosts a patient's awareness of the treatment of hypertension, leading to better compliance with drug intake and overall treatment. In addition, it is very useful for assessing the therapeutic effect and duration of action of drugs. HBP morning is also required for the diagnosis of morning hypertension as well as white coat hypertension and reverse white coat hypertension. The HBP monitors released in recent years can even measure blood pressure during sleep. The JSH 2004 regarding HBP monitoring was based on "The 2003 Guidelines for HBP Monitoring". As mentioned above, HBP monitoring is expected to contribute to improving the treatment of hypertension and medical economy. Both the blood pressure measured at a hospital and that measured at home are red blood pressures. It is impossible to determine a single specific blood pressure value for a patient, so it appears to be more rational to estimate the usual blood pressure from data obtained under various conditions. In this article, we review the clinical meaning of HBP monitoring based on the current situation and discuss problems with HBP monitoring and its application to daily clinical practice.

Antihypertensive Agents↗

Continuous arterial and venous blood gas monitoring during cardiopulmonary bypass.

A new monitoring technique, based on optical fluorescence chemistry, allows continuous monitoring of all blood gas variables during cardiopulmonary bypass. To evaluate the clinical performance of this monitor, we drew 220 arterial and 216 venous blood samples from 15 patients, and simultaneous blood gas values displayed by the monitor were compared with standard laboratory measurements. The continuous monitor predicted laboratory values with varying degrees of accuracy. (R2 values by linear regression: arterial oxygen tension 0.86, venous oxygen tension 0.36, arterial carbon dioxide tension 0.58, venous carbon dioxide tension 0.72, arterial pH 0.53, venous pH 0.58; pH 0.53, venous pH 0.58; p less than 0.0001). Monitor values of arterial oxygen tension overestimated laboratory values (bias = + 43.5 mm Hg), but the laboratory reference method likely underestimated true arterial oxygen tension in the high range achieved on bypass. Monitoring of venous oxygen tension was imprecise (precision = +/- 6.51 mmHg), regardless of whether stable conditions existed during the sampling period. Monitoring of carbon dioxide tension and pH showed small bias (carbon dioxide tension within 2 mm Hg, pH within 0.03) and good precision (carbon dioxide tension within 3 mm Hg, pH within 0.03). With the development of unstable conditions on bypass, monitor arterial oxygen tension values showed a changing relationship to corresponding laboratory values. In conclusion, arterial and venous carbon dioxide tension and pH monitoring provide acceptably accurate alternatives to laboratory measurement of these variables during cardiopulmonary bypass. Arterial oxygen tension monitoring accurately indicates changes in oxygen tension in the arterial oxygen tension range typically produced during extracorporeal circulation. Oxygen tension monitoring in the venous oxygen tension range is too imprecise for clinical decision-making purposes.

Aged↗

[The survey on the perinatal variables and the incidence of cerebral palsy for 12 years before and after the application of the fetal monitoring systems].

The effects of electrical fetal monitoring such as cardiotocogram (CTG) and nonstress test (NST) were studied during the years 1975-86 in 6,981 cases (6,893 singletons, 41 twins and 2 triplets). These cases were divided into three groups according to the mode of fetal monitoring. The first group was managed without electrical fetal monitoring (control group). The second was managed mainly with intrapartum fetal monitoring (transitional group) and the third was managed with antepartum and intrapartum fetal monitoring (fully monitored group). The incidence of cerebral palsy (CP) was investigated at the social health center during the same period. The introduction of intrapartum fetal monitoring resulted in a reduction in neonatal asphyxia from 7.0% in the control group to 5.2% and 4.3% in the transitional group and fully monitored group respectively. The perinatal mortality rate showed a significant reduction from 0.61% in the period without antepartum fetal monitoring to 0.31% in the fully monitored group, and this was attributed to the significant reduction in the number of stillbirths. The incidence of CP in the district decreased from 2.2 to 0.2 per 1,000 children during the period studied. In these circumstances, the caesarean section rate increased from 7.0% in the control group to 11.8% in the transitional group but decreased to 9.8% in the fully monitored group. These results showed the clinical and social benefits of electrical fetal monitoring.

Cerebral Palsy↗

Use of somatosensory evoked potentials for intraoperative monitoring of cerebral and spinal cord function.

EPs can be used in the operating room for monitoring the integrity of many levels of the central nervous system. SEPs can monitor the spinal cord, brain stem, and cerebral hemispheres. Such monitoring can alert the surgical team to the presence of complications, allowing prompt correction in some cases so as to prevent postoperative neurologic deficits. Monitoring can be done from stimulation of either the lower or upper extremity. Recordings can be taken over the scalp or can be made from electrodes put into the surgical site itself. Monitoring of the spinal cord is most often done for surgery involving scoliosis, spinal tumors, or arteriovenous malformations, and during crossclamping of the thoracic aorta. Animal models and human surgical experience has shown that monitoring the posterior columns is an effective way to assess the status of the motor pathways of the spinal cord, because the two pathways are both affected in almost all acute circumstances. Monitoring can also assess the functional status of the cerebral hemispheres. This is most often applied during carotid endarterectomy or repair of aneurysms of the carotid artery and its branches. Occasionally, this has also been applied to monitoring the cortex during cardiopulmonary bypass. Such EP monitoring does not cover the wide areas of cortex that can be monitored using EEG, but the EPs do tend to change and disappear at a level of ischemia nearer to the true critical level. Intraoperative median nerve EPs can also be used to identify the hand level of the motor and somatosensory cortex. Such identification of motor cortex can help guide neurosurgeons in their choice of how or where to perform a biopsy, excision, and the like. Overall, intraoperative evoked potential monitoring is becoming widespread because it is a practical way to help avoid neurologic complications, and it can be carried out using equipment already available in many hospitals. A substantial further review in this field can be found in Evoked Potential Monitoring in the Operating Room.

Brain Diseases↗

Neurologic intensive care unit monitoring.

Monitoring modalities unique to the neurologic intensive care unit include intracranial pressure monitors and neuroelectrophysiologic monitors. Each modality fullfills criteria for accuracy, responsivity during clinical change, and stability over time for trend analysis. Intracranial pressure monitoring may be accomplished by any of three approaches--ventricular catheter, subarachnoid bolt, or epidural pressure transducer. Intracranial pressure control has proved beneficial in at least three different illnesses--acute closed head injury, acute noncommunicating hydrocephalus, and Reye's syndrome. Other illnesses, such as cerebral hemorrhage, near drowning, meningitis, encephalitis, and cerebral mass lesions, are often associated with ICP elevations. Neuroelectrophysiologic monitoring encompassing electroencephalography (EEG), signal-processed EEG, and evoked potentials has proved to be most beneficial to the intensive care setting. Evoked potentials are most useful for monitoring patients in drug-induced coma or muscle paralysis in whom a clinical neurologic examination is unreliable. Focal neurologic deficits, incipient brainstem ischemia, and possibly brain death can be deduced from multimodality-evoked potentials (brainstem auditory and somatosensory). Evoked potential apparatus can be used to record sequential stimuli and trend changes. Signal-processed EEG apparatus (compressed spectral array and cerebral function monitor) are used to assess global or regional EEG activity for longer periods of time. Interpretation of signal-processed EEG recording requires some experience with this technique, but it is much easier to interpret than a standard 16-lead EEG. These monitors are useful in evaluating some forms of abnormal EEG activity and in monitoring gross changes in global or regional electrical activity. Currently available technology offers dynamic insight into the management of acute neurologic illnesses. The technology in evoked potential and signal processed EEG monitoring will eventually reduce the size and complexity of the instrumentation, making its application routine. Intracranial pressure monitoring is already routine in many intensive care units, although its use is occasionally sporadic. We believe that application of appropriate neurologic monitors improves therapy and outcome in neurologically injured and ill patients.

Critical Care↗

Evaluation of a portable prothrombin time monitor for home use by patients who require long-term oral anticoagulant therapy.

BACKGROUND: The anticoagulant activity of warfarin sodium is monitored by the prothrombin time (PT). The introduction of a portable PT monitor has raised the possibility that patients could reduce the inconvenience of anticoagulant therapy by measuring their PT at home. We performed this study to determine the feasibility and accuracy of home use of the portable PT monitor. METHODS: A prospective cohort study was performed in consecutive eligible patients who required long-term anticoagulant therapy. Patients performed multiple measurements of their PT at home by means of the portable monitor and at their usual laboratory within a 4-hour interval. The accuracy of the portable monitor was evaluated by two criteria for agreement. Standard agreement was achieved if the portable monitor and laboratory results were both either within or outside the patient's targeted therapeutic range or if the two results were within 0.4 international normalized ratio units of each other. Expanded agreement was achieved if both the portable monitor and laboratory results were within +/- 0.4 international normalized ratio units of the targeted therapeutic range. RESULTS: Forty patients (19 men and 21 women, aged 25 to 74 years) were followed up for 6 to 24 months by means of the portable PT monitor. The mean level of agreement achieved per patient was 83% (95% confidence interval, 79% to 87%) by the standard criteria and 96% (95% confidence interval, 94% to 98%) by the expanded criteria. Twenty-seven patients (68%) and 39 patients (98%) achieved more than 80% agreement by the standard and the expanded criteria, respectively. Questionnaire results revealed that 97% of the patients preferred using the portable monitor to measure their PT. CONCLUSIONS: Patients receiving long-term anticoagulant therapy achieved a high rate of clinically important agreement between self-measurements of the PT with the use of a portable monitor and laboratory PT results. Patients strongly preferred using the portable monitor to measure their PT levels. The use of the portable monitor as the primary method for measuring the PT can be recommended in selected patients receiving long-term anticoagulant treatment.

Administration, Oral↗

Further support for consistent self-monitoring as a vital component of successful weight control.

OBJECTIVE: This study attempted to replicate that of Baker and Kirschenbaum by providing a descriptive analysis of the relationship between self-monitoring and weight control. PROCEDURES: Fifty-nine women and men in long-term cognitive-behavioral treatment for obesity participated over an 8-week period. Percentages of participants who self-monitored consistently and the relationship between the variability in self-monitoring and weight change were examined. RESULTS: As in the previous study, a substantial minority of the participants in this research (26.3%) self-monitored all foods eaten on less than half of the days evaluated. The assertion of Baker and Kirschenbaum that self-monitoring is most appropriately viewed as both a state and a trait was supported by finding that the most consistent self-monitors lost more weight than the least consistent self-monitors; however, regardless of overall self-monitoring consistency, participants lost much more weight during their two most consistent weeks compared with their two least consistent weeks. Again, as in the previous study, only the more consistent quartile of self-monitors lost a substantial amount during the course of this study. DISCUSSION: The results of both studies taken together suggests that a reasonable target for consistency for self-monitoring within the context of a professional cognitive-behavioral treatment program may be self-monitoring all foods eaten on at least 75% of the days. If participants generally self-monitor on less than half of the days during participation in such programs, they may be very unlikely to succeed at weight loss both during the program and afterward.

Adult↗

Monitors: key mechanisms and roles in the development and aging of the consciousness and self.

A network of interacting neural structures, called monitors, exists in the mammalian brain in which data derived from sensory inputs and from memory stores is precisely displayed within the brain. The key function of monitors is to provide an 'ultimate monitor', proposed to be the locus that generates the phenomenon of conscious self awareness, with information that defines or maps the positions of the parts of an individual with respect to each other and with respect to external objects or events at specific times. The resolution of at least some of these monitors (e.g. some concerned with vision) is extremely great and approaches, in the case of vision, the precision with which images of external objects are projected onto the retina. This conclusion is based on the fact that an individual is able to perceive visual images with an acuity that closely approximates the fineness of resolution of the retinal image. The sensory signals that provide information about body part positions and those that provide information about the exterior are evidently integrated with each other in a suitable hierarchy of monitors so as to provide a coherent representation of self-vs.-environment. The logical 'framework' monitor for this integrated display-mapping is proposed to be that that maps the body in space and it is proposed that the locations of objects perceived through the touch sense and senses that deal with more remote items in the environment become superimposed on a map that extends or extrapolates the body space map beyond the body's physical boundaries, a learning process that occurs during development. The ultimate monitor not only receives a display of the synthetic representations derived currently through the integrative functions defined above, but also is provided with at least four other inputs from other different classes of monitors. One of these is a monitoring system that generates timing signals needed to separate inputs into a time order and to assign an order to them. It is proposed that it is awareness of these timing signals by the ultimate monitor that is the essential and indispensible input that generates the phenomenon of awareness. A second input to the monitor that is the self is a selected part of its own activities. This awareness of what the ultimate monitor is receiving, doing or planning to do in the future is the characteristic necessary for awareness of self.(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗

Comparison of continuous versus intermittent monitoring of atrial arrhythmias.

BACKGROUND: The ability of intermittent or symptom-based monitoring to accurately identify patients with atrial tachycardia/atrial fibrillation (AT/AF) and to quantify AT/AF burden is not well established. OBJECTIVES: The purpose of this study was to compare intermittent and symptom-based monitoring to continuous monitoring for (1) identification of patients with any AT/AF, (2) identification of patients with long-duration AT/AF, and (3) assessment of AT/AF burden. METHODS: Data from 574 pacemaker (AT500, Medtronic) patients were analyzed retrospectively over 1 year. The device recorded the amount of AT/AF detected each day. Intermittent monitoring (annual, quarterly, and monthly 24-hour Holter; 7-day and 30-day annual long-term recordings) was simulated by analyzing data from randomly selected days within a prescribed monitoring window. Symptom-based monitoring was approximated by analyzing days when patients indicated symptoms with an external activator. RESULTS: All intermittent and symptom-based monitoring resulted in significantly lower sensitivity (range 31%-71%) and negative predictive value (range 21%-39%) for identification of patients with any AT/AF (P <.001) and underestimated AT/AF burden (P <.001) compared with continuous monitoring. Sensitivity for identifying patients with long-duration episodes ranged from 23% to 58% (P <.001 vs continuous monitoring). Identification of patients with AT/AF and assessment of AT/AF burden with intermittent monitoring depended on the patient's actual AT/AF burden and improved with increasing frequency or duration of intermittent monitoring. CONCLUSION: Intermittent and symptom-based monitoring is highly inaccurate for identifying patients with any or long-duration AT/AF and for assessing AT/AF burden. Further investigation is required to determine if full AT/AF disclosure with implantable devices is effective in reducing stroke risk and facilitating maintenance of sinus rhythm.

Aged↗

A prospective randomized comparison of loop recorders versus Holter monitors in patients with syncope or presyncope.

BACKGROUND: The initial management of syncope or presyncope typically involves short-term cardiac monitoring using a Holter monitor. A loop recorder is used to extend the period of monitoring to increase the probability of obtaining a symptom-rhythm correlation. Loop recorders and Holter monitors are both used commonly, but their utility has not been compared prospectively. METHODS: Patients with syncope or presyncope referred for a Holter monitor or a loop recorder were assigned randomly to receive either a 48-hour Holter monitor or a loop recorder for 1 month as an initial diagnostic strategy. If the initial strategy was unsuccessful, patients were offered crossover to the alternate strategy. RESULTS: One hundred patients (mean [+/- SD] age, 56 +/- 20 years; 44 women) with syncope (n = 21), presyncope (n = 29), or both (n = 50) were enrolled. Of the 49 patients assigned randomly to an external loop recorder first, 31 (63%) had an arrhythmia identified or excluded, versus 12 (24%) of 51 patients assigned to a Holter monitor initially (P <0.0001). Arrhythmia was identified as a cause of syncope in 1 patient with a loop recorder, compared with no patients with a Holter monitor (P = 0.31). Of the 29 patients with negative results with Holter monitoring who went on to receive a loop recorder, 13 (45%) had arrhythmia excluded, compared with none of the 4 patients who crossed over to receive a Holter monitor. The overall probability of obtaining a symptom-rhythm correlation was 56% (44/78) for loop recorders versus 22% (12/55) for Holter monitors (P <0.0001). Despite patient education and test transmissions, 13 (23%) of 57 patients who had recurrence of their symptoms failed to activate their loop recorder properly. CONCLUSION: Loop recorders have a much higher diagnostic yield for patients with syncope or presyncope as compared with Holter monitors. The utility of loop recorders is limited by some patients' inability to operate them correctly.

Electrocardiography, Ambulatory↗