Patient Care and Monitoring Systems

Patient care

• Patient care is the focus of many clinical disciplines– Various disciplines sometimes overlaps – Each has its own primary focus, emphasis, and

methods of care delivery – Each discipline’s work is complex

• Collaboration among disciplines adds complexity.

• In all disciplines, the quality of clinical decisions depends in part on the quality of information available to the decision-maker.

Care Process

• Care begins with collecting data and assessing the patient’s current status

• Through cognitive processes specific to the discipline: – diagnostic labels are applied, – therapeutic goals are identified with timelines for evaluation, and – therapeutic interventions are selected and implemented

• At specified intervals: – patient is reassessed, – effectiveness of care is evaluated, and – therapeutic goals and interventions are continued or adjusted as

needed • If the reassessment shows that the patient no longer

needs care, services are terminated

Discipline in patient care

• Patient care is a multidisciplinary process centered on – the care recipient in the context of the – family, – significant others, and – community.

Information to Support Patient Care

• The information for direct patient care is defined in the answers to the following questions:– Who is involved in the care of the patient?– What information does each professional require to

make decisions?– From where, when, and in what form does the

information come?– What information does each professional generate?

Where, when, and in what form is it needed?

History

• The genesis of patient care systems occurred in the mid-1960’s.

• One of the first and most successful systems was the Technicon Medical Information System (TMIS), begun in 1965 as a collaborative project between Lockheed and El Camino Hospital in Mountain View, California.

• TMIS designed to simplify documentation through the use of standard order sets and care plans.

• More than three decades later, the technology has moved on.

Recent History

• Part of what changed users’ expectations for patient care systems was:

• Development and evolution of the HELP system at LDS Hospital in Salt Lake City, Utah. – Decision support to physicians during the process of

care – Managing and storing data– Support nursing care decisions – Aggregate data for research leading to improved

patient care.

Patient Care ComponentsPatient-CareComponent

Examples: Hospital Examples: Ambulatory Care

Problem lists Problem-Oriented MedicalInformation System(PROMIS), Medical CenterHospital of Vermont,Burlington, VT [Weed, 1975];Tri-Service MedicalInformation System(TRIMIS), Department ofDefense [Bickel, 1979]

Computer-Stored AmbulatoryRecord (COSTAR),Massachusetts GeneralHospital, Boston, MA[Barnett, 1976];Summary Time-OrientedRecord (STOR), University ofCalifornia, San Francisco, CA[Whiting-O'Keefe et al., 1980]

Summary reports Technicon Medical InformationSystem (TMIS),Clinical Center at NationalInstitutes of Health, Bethesda,MD [Hodge, 1990];Decentralized HospitalComputer Program (DHCP),Department of Veteran’sAffairs [Ivers & Timson, 1985]

Regenstrief, RegenstriefInstitute,Indianapolis, IN [McDonald,1976]; Computer-StoredAmbulatory Record(COSTAR), MassachusettsGeneral Hospital, Boston, MA[Barnett, 1976]

Order entry Health Evaluation LogicalProcessing (HELP), LatterDay Saints Hospital, Salt LakeCity, UT [Kuperman et al.,1991]; Technicon MedicalInformation System (TMIS),Clinical Center at NationalInstitutes of Health, Bethesda,MD [Hodge, 1990];

The Medical Record (TMR),Duke University MedicalCenter, Durham, NC[Hammond et al., 1980];

Patient-Care Component Examples: Hospital Examples: AmbulatoryCare

Results review University of Missouri--Columbia System, Columbia,MO [Lindberg, 1965];Decentralized HospitalComputer Program (DHCP),Department of Veteran’sAffairs[Ivers & Timson,1985]

Computer-StoredAmbulatoryRecord (COSTAR),Massachusetts GeneralHospital, Boston, MA[Barnett, 1976]; SummaryTime-Oriented Record(STOR), University ofCalifornia, San Francisco,CA [Whiting-O'Keefe et al.,1980]

Nursing protocols and careplans

Health Evaluation LogicalProcessing (HELP), LatterDay Saints Hospital, SaltLake City, UT [Kuperman etal., 1991];Technicon MedicalInformation System (TMIS),El Camino Hospital,Mountain View, CA[Watson, 1977]

Alerts and reminders Health Evaluation LogicalProcessing (HELP), LatterDay Saints Hospital, SaltLakeCity, UT [Kuperman et al.,1991];Beth Israel Hospital System,Boston, MA [Safran et al.,1989]

Regenstrief, RegenstriefInstitute,Indianapolis, IN [McDonald,1976];The Medical Record (TMR),Duke University MedicalCenter,Durham, NC [Hammond etal.,1980]

HELP System at LDS Hospital

Patient Monitoring

• “Repeated or continuous observations or measurements of the patient, his or her physiological function, and the function of life support equipment, for the purpose of guiding management decisions, including when to make therapeutic interventions, and assessment of those interventions” [Hudson, 1985, p. 630].

• A patient monitor may not only alert caregivers to potentially life-threatening events; many provide physiologic input data used to control directly connected life-support devices.

History of Physiological data measurements

• 1625 Santorio-measure body temperature with spirit thermomoeter. – Santorio was first to apply a numerical scale to his thermo

scope, which later evolved into the thermometer. • Timing pulse with pendulum. Principles were established by Galileo.

These results were ignored.– Claudius Galen, was physician to five Roman emperors. – He also understood the value of the pulse in diagnosis. – John Floyer, 1707, acknowledged Galen's skill in identifying

various pulse beats, but was appalled that even 1500 years later the doctors were still not using any standard procedure for measuring them.

– He said that the pulse should be counted using a watch or a clock and he had a special pulse watch made for timing 60 seconds.

– He published his findings in his works called " Physician's Pulse Watch" , but doctors largely ignored Floyer's advice for over a hundred years.

History• 1852 Ludwig Taube Course of patient’s fever

measurement• At this time Temperature, pulse rate respiratory rate had

become standard vital signs.• Scipione Riva-Rocci introduced the sphygmomanometer

(blood pressure cuff). (4th vital sign).– Scipione Riva-Rocci his fundamental contribution (1896) was the

mercury sphygmomanometer, which is easy to use and gives sufficiently reliable results.

– This device, the standard instrument for measuring blood pressure, led to many new developments in the therapy of hypertension disease.

• Nikolai koroktoff applied the cuff with the stethoscope (developed by Renne Lannec-French Physician) to measure systolic and diastolic blood pressures.

What is blood pressure?• Blood is carried from the heart to all parts of your body in vessels

called arteries. • Blood pressure is the force of the blood pushing against the walls of

the arteries. • Each time the heart beats (about 60-70 times a minute at rest), it

pumps out blood into the arteries. • Your blood pressure is at its highest when the heart beats, pumping

the blood. • This is called systolic pressure. • When the heart is at rest, between beats, your blood pressure falls. • This is the diastolic pressure. • Blood pressure is always given as these two numbers, the systolic

and diastolic pressures. – Both are important.

• When the two measurements are written down, the systolic pressure is the first or top number, and the diastolic pressure is the second or bottom number (for example, 120/80).

Harvey Cushing

• 1900s Harvey Cushing introduced an apparatus to measure blood pressure during operations.

• Raised the questions:1. Are we collecting too much data? 2. Are the instruments used in clinical medicine too accurate? 3. Would not approximated values be just as good?

Cushing answered his own questions by stating that vital-sign measurement should be made routinely and that accuracy was important [Cushing, 1903].

History (Cont.)• 1903 Willem Einthoven devised the string galvanometer

– An instrument used to detect, measure, and determine the direction of small electric currents by means of mechanical effects produced by a current-carrying coil in a magnetic field.

• to measure ECG (Nobel Prize 1924)– 1901, Einthoven invented a new galvanometer for producing electrocardiograms

using a fine quartz string coated in silver based on ideas by Deprez and d'Arsonval, who used a wire coil. His "string galvanometer" weighs 600 pounds. Einthoven acknowledged the similar system by Clément Ader (1841-1926), but later, in 1909, calculated that his galvanometer was in fact many thousands of times more sensitive.

• Improvement over the capillary galvanometer, and the original galvanometer invented by Johann Salomo Christoph Schweigger (1779-1857) in Halle in 1820. Einthoven published the first electrocardiogram recorded on a string galvanometer in 1902.

• 1905, Einthoven began transmitting electrocardiograms from the hospital to his laboratory 1.5 km away via telephone cable.

• On March 22nd that year the first telecardiogram was recorded from a healthy and vigorous man and the tall R waves were attributed to his cycling from laboratory to hospital for the recording.

electrocardiograph

• An instrument used in the detection and diagnosis of heart abnormalities that measures electrical potentials on the body surface and generates a record of the electrical currents associated with heart muscle activity. Also called cardiograph.

History• 1950 The ICU’s were established to meet increasing

demand for acute and intensive care required by patients with complex disorders.

• 1963 Day - treatment of post–myocardial-infarction patients in a coronary-care unit reduced mortality by 60 percent.

• 1968 Maloney - having the nurse record vital signs every few hours was “only to assure regular nurse–patient contact”.

• Late ‘60s and early ‘70 bedside monitors built around bouncing balls or conventional oscilloscope.

• ‘90 Computer-based patient monitors - Systems with: – database functions, – report-generation systems, and – some decision-making capabilities.

Myocardial Infarction

• “Heart attack“, non-medical term, is "Myocardial Infarction".

• Either term is scary. • "Myocardial Infarction" (abbreviated as "MI") means

there is death of some of the muscle cells of the heart as a result of a lack of supply of oxygen and other nutrients.

• This lack of supply is caused by closure of the artery ("coronary artery") that supplies that particular part of the heart muscle with blood.

• This occurs 98% of the time from the process of arteriosclerosis ("hardening of the arteries") in coronary vessels.

Patient Monitoring in ICUs• Categories of patients who need physiologic

monitoring:1. Patients with unstable physiologic regulatory

systems; • Example: a patient whose respiratory system is suppressed

by a drug overdose or anesthesia.

2. Patients with a suspected life-threatening condition; • Example: a patient who has findings indicating an acute

myocardial infarction (heart attack).

3. Patients at high risk of developing a life-threatening condition; • Example: patients immediately post open-heart surgery, or a

premature infant whose heart and lungs are not fully developed.

4. Patients in a critical physiological state; • Example: patients with multiple trauma or septic shock.

Care of the Critically Ill• Requires prompt and accurate decisions. • ICUs use computers almost universally :

– acquire physiological data frequently or continuously, (e.g. blood pressure)

– communicate information from data-producing systems to remote locations (e.g., laboratory and radiology departments)

– store, organize, and report data– integrate and correlate data from multiple sources – provide clinical alerts and advisories based on multiple sources

of data– function as a decision-making tool that health professionals may

use in planning then care of critically ill patients– measure the severity of illness for patient classification purposes– analyze the outcomes of ICU care in terms of clinical

effectiveness and cost-effectiveness

Intensive care Unit Bed

Use of computers for patient monitoring

Automaticcontrol

Patient equipment Computer DBMS

Reports

Mouse andkeyboard

Display

Transducers

Clinician

ICU

Bed Bed BedBed

Nurse station TelemetryWEB connection

Some instruments in mind

Types of Data Used in Patient monitoring in different ICU’s

Continuousvariables

Sampledvariables

Coded Data Free Text

CardiacECG

Heart rate(HR)HR variabilityPVCs

TemperatureCentralPeripheral

Patientobservation Color Pain Position Etc.,

All otherobservationsorinterventionsthat cannotbe measuredor coded

Blood pressureArterial/venousPulmonaryLeft/rightatrial/ventricularSystolic/DyastolPer beat/averageSystolic timeintervals

Blood ChemistryHbPHPO2

PCO2

Etc.,

Interventions Infusions Drugs Defibrillation Artificialventilations Anesthesia

RespiratoryFrequencyDepth/vol/flowPressure/ResistRespiratorygases

Fluid balanceInfusionsBlood plasmaUrine loss

NeurologicalEEGFrequencycomponentsAmplitudesCoherence

Patient monitoring

Features MatrixECG 3 leadsECG 5 leadsECG 10 leadsRespirationInvasive BPDual Temp/C.O.NIBPSpO2

Understanding ECG - Normal ECG summary

Normal rate Between 50bpm and 99bpm Sinus rhythm Normal P wave before each QRS

complex Regular QRS complexes May be a variation with respiration

Normal Axis Axis between 30 degrees and +90 degrees

P wave May be negative in Lead V1 Normal morphology PR interval between 0.12 and 0.2 seconds

QRS complex Normal morphology No longer than 0.12 seconds Q waves are normal in Leads I, aVL and V6 R waves increase across the chest leads

T waves Normal morphology May be inverted in Lead III,aVR and V1 May also be inverted in V2 and V3 in blacks

QT interval QTc between 0.35 and 0.43 seconds U waves Small U waves often seen in leads V2

V4

Respiration• Rate range: 1 to 200 breaths/min• Impedance range: 100 to 1000 ohms at 52.6 kHz • Detection sensitivity range: 0.4 to 10 ohms impedance variation • Low rate alarm range: 1 to 199 breaths/min • High rate alarm range: 2 to 200 breaths/min • Apnea alarm rate: 0 to 30 seconds in one-second increments • Cardiac artifact alarm • Waveform display bandwidth: 0.05 to 2.5 Hz (-3 dB) • Analog output: Selectable • Trends: 24 hours with 1-minute resolution • Invasive Blood pressure• Catheter sites: Arterial, pulmonary arterial, central venous, left

atrial,• intracranial, right atrial, femoral arterial, umbilical venous, umbilical

arterial, and special. • Trends: 24 hours with 1-minute resolution