Monitoring (medicine)From Wikipedia, the free encyclopedia

Display device of a medical monitor as used inanesthesia.In medicine,monitoringis the observation of a disease, condition or one or several medical parameters over time.It can be performed by continuously measuring certain parameters by using amedical monitor(for example, by continuously measuringvital signsby a bedside monitor), and/or by repeatedly performingmedical tests(such asblood glucose monitoringwith aglucose meterin people withdiabetes mellitus).Transmitting data from a monitor to a distant monitoring station is known astelemetryorbiotelemetry.Contents[hide] 1Classification by target parameter 1.1Vital parameters 2Medical monitor 2.1Components 2.1.1Sensor 2.1.2Translating component 2.1.3Display device 2.1.4Communication links 2.1.5Other components 2.2Mobile appliances 3Interpretation of monitored parameters 3.1Change in status versus test variability 4Techniques in development 4.1Examples and applications 5See also 6References 7Further reading 8External linksClassification by target parameter[edit]Monitoring can be classified by the target of interest, including: Cardiac monitoring, which generally refers to continuouselectrocardiographywith assessment of the patients condition relative to their cardiac rhythm. A small monitor worn by an ambulatory patient for this purpose is known as aHolter monitor. Cardiac monitoring can also involvecardiac outputmonitoring via an invasiveSwan-Ganz catheter. Hemodynamicmonitoring, which monitors theblood pressureandblood flowwithin the circulatory system. Blood pressure can be measured either invasively through an inserted blood pressuretransducerassembly, or noninvasively with an inflatable blood pressure cuff. Respiratory monitoring, such as: Pulse oximetrywhich involves measurement of the saturated percentage ofoxygenin theblood, referred to as SpO2, and measured by aninfraredfinger cuff Capnography, which involves CO2measurements, referred to asEtCO2or end-tidalcarbon dioxideconcentration. The respiratory rate monitored as such is called AWRR orairway respiratory rate) Respiratory rate monitoring through a thoracic transducer belt, an ECG channel or via capnography Neurological monitoring, such as ofintracranial pressure. Also, there are special patient monitors which incorporate the monitoring of brain waves (electroencephalography), gas anesthetic concentrations,bispectral index(BIS), etc. They are usually incorporated into anesthesia machines. Inneurosurgeryintensive care units, brain EEG monitors have a larger multichannel capability and can monitor other physiological events, as well. Blood glucose monitoring Childbirth monitoring Body temperaturemonitoringthrough anadhesive padcontaining athermoelectrictransducer.Vital parameters[edit]

Ananesthetic machinewith integrated systems for monitoring of several vital parameters, includingblood pressureandheart rate.Monitoring ofvital parameterscan include several of the ones mentioned above, and most commonly include at leastblood pressureandheart rate, and preferably alsopulse oximetryandrespiratory rate. Multimodal monitors that simultaneously measure and display the relevant vital parameters are commonly integrated into the bedside monitors incritical care units, and theanesthetic machinesinoperating rooms. These allow for continuous monitoring of a patient, with medical staff being continuously informed of the changes in general condition of a patient. Some monitors can even warn of pending fatalcardiacconditions before visible signs are noticeable to clinical staff, such asatrial fibrillationorpremature ventricular contraction(PVC).Medical monitor[edit]Amedical monitororphysiological monitoris amedical deviceused for monitoring. It can consist of one or moresensors, processing components,display devices(which are sometimes in themselves called "monitors"), as well as communication links for displaying or recording the results elsewhere through a monitoring network.Components[edit]Sensor[edit]Sensors of medical monitors includebiosensorsand mechanical sensors.Translating component[edit]The translating component of medical monitors is responsible for converting the signals from the sensors to a format that can be shown on the display device or transferred to an external display or recording device.Display device[edit]Physiological data are displayed continuously on aCRT,LEDorLCDscreen asdata channelsalong the time axis, They may be accompanied bynumerical readoutsof computed parameters on the original data, such as maximum, minimum and average values, pulse and respiratory frequencies, and so on.Besides the tracings of physiological parameters along time (X axis), digital medical displays have automatednumeric readoutsof the peak and/or average parameters displayed on the screen.Modern medical display devices commonly usedigital signal processing(DSP), which has the advantages ofminiaturization,portability, and multi-parameter displays that can track many different vital signs at once.Oldanalogpatient displays, in contrast, were based onoscilloscopes, and had one channel only, usually reserved for electrocardiographic monitoring (ECG). Therefore, medical monitors tended to be highly specialized. One monitor would track a patient'sblood pressure, while another would measurepulse oximetry, another the ECG. Later analog models had a second or third channel displayed in the same screen, usually to monitorrespirationmovements andblood pressure. These machines were widely used and saved many lives, but they had several restrictions, including sensitivity toelectrical interference, base level fluctuations and absence of numeric readouts and alarms.Communication links[edit]Several models of multi-parameter monitors are networkable, i.e., they can send their output to a central ICU monitoring station, where a single staff member can observe and respond to several bedside monitors simultaneously.Ambulatory telemetrycan also be achieved by portable, battery-operated models which are carried by the patient and which transmit their data via awirelessdata connection.Digital monitoring has created the possibility, which is being fully developed, of integrating the physiological data from the patient monitoring networks into the emerging hospitalelectronic health recordand digital charting systems, using appropriatehealth care standardswhich have been developed for this purpose by organizations such asIEEEandHL7. This newer method of charting patient data reduces the likelihood of human documentation error and will eventually reduce overall paper consumption. In addition,automated ECG interpretationincorporates diagnostic codes automatically into the charts. Medical monitor'sembedded softwarecan take care of the data coding according to these standards and send messages to the medical records application, which decodes them and incorporates the data into the adequate fields.Long-distance connectivity can avail fortelemedicine, which involves provision ofclinical health careat a distance.Other components[edit]A medical monitor can also have the function to produce an alarm (such as using audible signals) to alert the staff when certain criteria are set, such as when some parameter exceeds of falls the level limits.Mobile appliances[edit]An entirely new scope is opened with mobile carried monitors, even such in sub-skin carriage. This class of monitors delivers information gathered in body-area networking (BAN) to e.g.smart phonesand implementedautonomous agents.Interpretation of monitored parameters[edit]Monitoring of clinical parameters is primarily intended to detect changes (or absence of changes) in the clinical status of an individual. For example, the parameter ofoxygen saturationis usually monitored to detect changes inrespiratorycapability of an individual.Change in status versus test variability[edit]When monitoring a clinical parameters, differences between test results (or values of a continuously monitored parameter after a time interval) can reflect either (or both) an actual change in the status of the condition or atest-retest variabilityof the test method.In practice, the possibility that a difference is due to test-retest variability can almost certainly be excluded if the difference is larger than a predefined "critical difference". This "critical difference" (CD) is calculated as:[1]

, where:[1] K, is a factor dependent on the preferred probability level. Usually, it is set at 2.77, which reflects a 95%prediction interval, in which case there is less than 5% probability that a test result would become higher or lower than the critical difference by test-retest variability in the absence of other factors. CVais the anaytical variation CViis theintra-individual variabilityFor example, if a patient has a hemoglobin level of 100 g/L, the anaytical variation (CVa) is 1.8% and the intra-individual variabilityCViis 2.2%, then the critical difference is 8.1 g/L. Thus, for changes of less than 8 g/L since a previous test, the possibility that the change is completely caused by test-retest variability may need to be considered in addition to considering effects of, for example, diseases or treatments.Critical differences for someblood tests[1]

Sodium3%

Potassium14%

Chloride4%

Urea30%

Creatinine14%

Calcium5%

Albumin8%

Fasting glucose15%

Amylase30%

Carcinoembryonic antigen69%

C-reactive protein43%[2]

Glycosylated hemoglobin21%

Hemoglobin8%

Erythrocytes10%

Leukocytes32%

Platelets25%

Unless otherwise specified, then reference for critical values isFraser 1989[1]

Critical differences for other tests include early morning urinary albumin concentration, with a critical difference of 40%.[1]Techniques in development[edit]Some or all of this article'slisted sourcesmay not bereliable.Please help this article by looking for better, more reliable sources, or by checking whether the references meet the criteria for reliable sources. Unreliable citations may be challenged or deleted.(October 2011)

The development of new techniques for monitoring is an advanced and developing field insmart medicine, biomedical-aidedintegrative medicine,alternative medicine,self-tailoredpreventive medicineandpredictive medicinethat emphasizes monitoring of comprehensive medical data of patients, people at risk and healthy people using advanced, smart, minimallyinvasivebiomedical devices,biosensors,lab-on-a-chip(in the futurenanomedicine[3][4]devices likenanorobots) and advancedcomputerizedmedical diagnosisand early warning tools over a short clinical interview anddrug prescription.Asbiomedical research,nanotechnologyandnutrigenomicsadvances, realizing the human body'sself-healingcapabilities and the growing awareness of the limitations ofmedical interventionby chemicaldrugs-only approach of old school medical treatment, new researches that shows the enormous damage medications can cause,[5][6]researchers are working to fulfill the need for a comprehensive further study and personal continuousclinical monitoringof health conditions while keeping legacy medical intervention as a last resort.In many medical problems, drugs offer temporary relief of symptoms while therootof a medical problem remains unknown without enough data of all ourbiological systems[7]. Our body is equipped with sub-systems for the purpose of maintaining balance and self healing functions. Intervention without sufficient data might damage those healing sub systems.[7]Monitoring medicine fills the gap to prevent diagnosis errors and can assist in future medical research by analyzing alldataof many patients.

Given ImagingCapsule endoscopyExamples and applications[edit]The development cycle in medicine is extremely long, up to 20 years, because of the need for U.S.Food and Drug Administration(FDA) approvals, therefore many of monitoring medicine solutions are not available today in conventional medicine.

The PASCAL Dynamic Contour Tonometer. A monitor for detection of increasedintraocular pressure.Blood glucose monitoringIn vivoblood glucose monitoringdevices can transmit data to a computer that can assist with daily life suggestions forlifestyleornutritionand with thephysiciancan make suggestions for further study in people who are at risk and help preventdiabetes mellitus type 2.[8]Stress monitoringBio sensors may provide warnings when stress levels signs are rising before human can notice it and provide alerts and suggestions.[9]Serotonin biosensorFutureserotoninbiosensors may assist withmooddisorders anddepression.[10]Continuous blood test based nutritionIn the field ofevidence-based nutrition, alab-on-a-chipimplantthat can run 24/7blood testsmay provide a continuous results and a coumputer can provide nutritaion suggestions or alerts.Psychiatrist-on-a-chipIn clinical brain sciencesdrug deliveryand in vivoBio-MEMSbasedbiosensorsmay assist with preventing and early treatment of mental disordersEpilepsy monitoringInepilepsy, next generations oflong-term video-EEG monitoringmay predictepileptic seizureand prevent them with changes of daily life activity likesleep,stress,nutritionandmoodmanagement.[11]Toxicity monitoringSmart biosensors may detect toxic materials suchmercuryandleadand provide alerts.[12]