Patient Care and Monitoring Systems
Patient Care
Patient care is central to many clinical disciplines.
Disciplines often overlap but have unique focuses, emphases, and care delivery methods.
The work in each discipline is complex.
Collaboration increases complexity.
Clinical decisions rely on the quality of available information.
Care Process
Care starts with data collection and patient status assessment.
Cognitive processes lead to:
Diagnostic labels.
Therapeutic goals with timelines.
Selection and implementation of therapeutic interventions.
Regular intervals:
Patient reassessment.
Care effectiveness evaluation.
Continuation or adjustment of goals and interventions.
Service termination when the patient no longer needs care.
Discipline in Patient Care
Patient care is multidisciplinary.
Centered on the care recipient within the context of:
Family.
Significant others.
Community.
Information to Support Patient Care
Information is defined by answering:
Who is involved in patient care?
What information is needed for decisions?
Where does the information come from, when, and in what form?
What information is generated, where, when, and in what form is it needed?
HELP System at Hospital (Transcribed)
The HELP system appears to be an integrated clinical data base. It consists of the following components.
Knowledge Database: Including infectious disease plans, nursing procedure charting
Input: From nurses, pharmacy, ECG, Lab, X-Ray, Blood Gas Lab, Surgery Schedule and so on.
Integrated Clinical Data Base: Including Clinical Data, Interpretations, Protocols
Output: Surgery & Anesthesia Charting, Laboratory
Longitudinal patient Data Repository (LDR)
Patient Monitoring
Definition: Repeated or continuous observations/measurements of the patient, physiological function, and life support equipment function.
Purpose: To guide management decisions, including therapeutic interventions and their assessment [Hudson, 1985, p. 630].
Function: Alerts caregivers and provides physiological input data to control life-support devices.
History of Physiological Data Measurements
1625 Santorio:
Measured body temperature with a spirit thermometer.
First to apply a numerical scale to the thermo scope, which evolved into the thermometer.
Timing pulse with pendulum (Galileo's principles):
Claudius Galen: Understood pulse value in diagnosis.
John Floyer (1707): Advocated for standardized pulse measurement using a watch.
Floyer created a pulse watch for timing 60 seconds.
His findings were published in "Physician's Pulse Watch," but were largely ignored for a century.
1852 Ludwig Taube: Course of patient’s fever measurement
History Continued
Temperature, pulse rate, and respiratory rate became standard vital signs.
Scipione Riva-Rocci:
Introduced the sphygmomanometer (blood pressure cuff).
His mercury sphygmomanometer (1896) was easy to use and reliable.
Led to new developments in hypertension therapy.
Nikolai Koroktoff:
Applied the cuff with a stethoscope to measure systolic and diastolic blood pressures.
The stethoscope was developed by Renne Lannec, a French Physician.
What is Blood Pressure
Blood travels from the heart through arteries.
Blood pressure is the force of blood against artery walls.
The heart beats (60-70 times per minute at rest), pumping blood into arteries.
Systolic pressure: Highest pressure when the heart beats.
Diastolic pressure: Pressure when the heart is at rest between beats.
Blood pressure is given as systolic/diastolic.
Example: 120/80, both values are important.
Harvey Cushing
1900s: Introduced an apparatus to measure blood pressure during operations.
Raised questions:
Are we collecting too much data?
Are instruments too accurate?
Would approximated values suffice?
Cushing answered that vital-sign measurement should be routine and accuracy is important [Cushing, 1903].
History (Cont.)
1903 Willem Einthoven devised the string galvanometer
Instrument to measure small electric currents.
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.
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
Instrument used to detect and diagnose heart abnormalities.
Measures electrical potentials on the body surface.
Generates a record of electrical currents during heart muscle activity; also called a cardiograph.
History (cont.)
1950s: ICUs established to meet the demand for acute care for patients with complex disorders.
1963 Day: Treatment of post-myocardial-infarction patients in coronary-care units reduced mortality by 60 percent.
1968 Maloney: Nurse recording vital signs was "only to assure regular nurse–patient contact".
Late ‘60s and early ‘70s: Bedside monitors built around bouncing balls or conventional oscilloscope.
‘90s: Computer-based patient monitors with:
Database functions.
Report generation.
Some decision-making capabilities.
Myocardial Infarction
"Heart attack" is the non-medical term but "Myocardial Infarction" is used in the medical field.
"Myocardial Infarction" (MI) means death of some heart muscle cells due to lack of oxygen and nutrients.
Caused by closure of a coronary artery.
98% of the time results from arteriosclerosis ("hardening of the arteries") in coronary vessels.
Patient Monitoring in ICUs
Categories of patients needing monitoring:
Unstable physiological regulatory systems.
Example: respiratory system suppressed by a drug overdose or anesthesia.
Suspected life-threatening condition.
Example: acute myocardial infarction (heart attack).
High risk of developing a life-threatening condition.
Example: post open-heart surgery patients, or premature infants.
Critical physiological state.
Example: multiple trauma or septic shock patients.
Care of the Critically Ill
Requires prompt and accurate decisions.
ICUs use computers for:
Frequent/continuous physiological data acquisition (e.g., blood pressure).
Communicating information to remote locations (e.g., labs, radiology).
Data storage, organization, and reporting.
Integrating and correlating data from multiple sources.
Clinical alerts and advisories based on data sources.
Decision-making tools for planning patient care.
Measuring illness severity for patient classification.
Analyzing ICU care outcomes in terms of clinical and cost-effectiveness.
Use of computers for patient monitoring
Automatic control of patient equipment
System includes: Computer, DBMS (database management system), Mouse and keyboard Display, Transducers, Clinician
Types of Data Used in Patient Monitoring in different ICU’s
Continuous variables:
Cardiac: ECG, Heart rate (HR), HR variability, PVCs
Blood pressure: Arterial/venous, Pulmonary, Left/right atrial/ventricular, Systolic/Diastolic, Per beat/average, Systolic time intervals
Respiratory: Frequency, Depth/vol/flow, Pressure/Resist, Respiratory gases
Fluid balance: Infusions, Blood plasma, Urine loss
Neurological: EEG, Frequency components, Amplitudes, Coherence
Sampled variables:
Temperature: Central Peripheral
Blood Chemistry:
Interventions: Infusions, Drugs, Defibrillation, Artificial ventilations, Anesthesia
Coded Data: Patient observation Color Pain Position
Free Text: All other observations or interventions that cannot be measured or coded
Patient Monitoring Features Matrix
Common features include:
ECG (3, 5, or 10 leads)
Respiration
Invasive Blood Pressure (IBP)
Dual Temperature/Cardiac Output
Non-Invasive Blood Pressure (NIBP)
Pulse Oximetry (SpO2)
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
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