INTRODUCTION TO INTRODUCTION TO PATIENT MONITORINGPATIENT MONITORING

D. John Doyle D. John Doyle MD PhD FRCPCMD PhD FRCPC

Cleveland Clinic FoundationCleveland Clinic Foundation

Revision 1.1 33 Slides January 2006Revision 1.1 33 Slides January 2006

STA Patient Monitoring INTRODUCTION Vol 1 Rev 1.1.pptSTA Patient Monitoring INTRODUCTION Vol 1 Rev 1.1.ppt

Monitoring: A Monitoring: A DefinitionDefinition

... interpret available clinical ... interpret available clinical data to help recognize present or data to help recognize present or future mishaps or unfavorable future mishaps or unfavorable system conditionssystem conditions

... not restricted to anesthesia ... not restricted to anesthesia (change “clinical data” above to “system (change “clinical data” above to “system data” to apply to aircraft and nuclear power data” to apply to aircraft and nuclear power plantsplants))

Patient Monitoring and Patient Monitoring and ManagementManagement

Involves …Involves … Things you measureThings you measure (physiological measurement, such (physiological measurement, such

as BP or HR)as BP or HR)

Things you observeThings you observe (e.g. observation of pupils)(e.g. observation of pupils)

Planning to avoid troublePlanning to avoid trouble (e.g. planning induction of (e.g. planning induction of

anesthesia or planning extubation)anesthesia or planning extubation)

Inferring diagnosesInferring diagnoses (e.g. unilateral air entry may mean (e.g. unilateral air entry may mean

endobronchial intubation)endobronchial intubation)

Planning to get out of troublePlanning to get out of trouble (e.g. differential (e.g. differential

diagnosis and response algorithm formulation)diagnosis and response algorithm formulation)

Monitoring in the Monitoring in the PastPast

Visual Visual monitoring of monitoring of respiration and respiration and overall clinical overall clinical appearanceappearance

Finger on pulseFinger on pulse Blood pressure Blood pressure

(sometimes)(sometimes)

Monitoring in the Monitoring in the PastPast

Finger on the pulse

Harvey Cushing Harvey Cushing Not just a famous neurosurgeon … Not just a famous neurosurgeon …

but the father of anesthesia but the father of anesthesia monitoringmonitoring Invented and popularized Invented and popularized

the anesthetic chartthe anesthetic chart Recorded both BP and HRRecorded both BP and HR Emphasized the relationship Emphasized the relationship

between vital signs and between vital signs and neurosurgical eventsneurosurgical events ( increased intracranial pressure leads ( increased intracranial pressure leads to hypertension and bradycardia )to hypertension and bradycardia )

Monitoring in the Monitoring in the PresentPresent

Standardized basic monitoring Standardized basic monitoring

requirements (guidelines) from the ASA requirements (guidelines) from the ASA

(American Society of Anesthesiologists), (American Society of Anesthesiologists),

CAS (Canadian Anesthesiologists’ Society) CAS (Canadian Anesthesiologists’ Society)

and other national societiesand other national societies Many integrated monitors availableMany integrated monitors available Many special purpose monitors availableMany special purpose monitors available Many problems with existing monitors Many problems with existing monitors

(e.g., cost, complexity, reliability, (e.g., cost, complexity, reliability, artifacts)artifacts)

ASA Monitoring GuidelinesASA Monitoring Guidelines

STANDARD I

Qualified anesthesia personnel shall be present in the room throughout the conduct of all general anesthetics, regional anesthetics and monitored anesthesia care.http://www.asahq.org/publicationsAndServices/standards/http://www.asahq.org/publicationsAndServices/standards/02.pdf02.pdf

ASA Monitoring GuidelinesASA Monitoring Guidelines

STANDARD II

During all anesthetics, the patient’s oxygenation, ventilation, circulation and temperature shall be continually evaluated.

http://www.asahq.org/publicationsAndServices/standards/http://www.asahq.org/publicationsAndServices/standards/02.pdf02.pdf

““The only indispensable monitor is the The only indispensable monitor is the

presence, at all times, of a physician or an presence, at all times, of a physician or an

anesthesia assistant, under the immediate anesthesia assistant, under the immediate

supervision of an anesthesiologist, with supervision of an anesthesiologist, with

appropriate training and experience. appropriate training and experience.

Mechanical and electronic monitors are, at best, Mechanical and electronic monitors are, at best,

aids to vigilance. Such devices assist the aids to vigilance. Such devices assist the

anesthesiologist to ensure the integrity of the anesthesiologist to ensure the integrity of the

vital organs and, in particular, the adequacy of vital organs and, in particular, the adequacy of

tissue perfusion and oxygenation.”tissue perfusion and oxygenation.”

CAS Monitoring Guidelines CAS Monitoring Guidelines

The following are The following are requiredrequired: : Pulse oximeter Pulse oximeter Apparatus to measure blood pressure, Apparatus to measure blood pressure,

either directly or noninvasively either directly or noninvasively Electrocardiography Electrocardiography Capnography, when endotracheal tubes or Capnography, when endotracheal tubes or

laryngeal masks are inserted. laryngeal masks are inserted. Agent-specific anesthetic gas monitor, when Agent-specific anesthetic gas monitor, when

inhalation anesthetic agents are used. inhalation anesthetic agents are used.

CAS Monitoring Guidelines CAS Monitoring Guidelines

The following shall be exclusively The following shall be exclusively available for each patient: available for each patient: Apparatus to measure temperature Apparatus to measure temperature Peripheral nerve stimulator, when Peripheral nerve stimulator, when

neuromuscular blocking drugs are used neuromuscular blocking drugs are used Stethoscope — either precordial, Stethoscope — either precordial,

esophageal or paratracheal esophageal or paratracheal Appropriate lighting to visualize an Appropriate lighting to visualize an

exposed portion of the patient. exposed portion of the patient.

CAS Monitoring GuidelinesCAS Monitoring Guidelines

The following shall be immediately The following shall be immediately available: available:

Spirometer for measurement of tidal Spirometer for measurement of tidal volume. volume.

CAS Monitoring Guidelines CAS Monitoring Guidelines

Detecting Mishaps Using Detecting Mishaps Using MonitorsMonitors

1. Disconnection1. Disconnection

2. Hypoventilation2. Hypoventilation

3. 3. Esophageal intubationEsophageal intubation

4. Bronchial 4. Bronchial intubationintubation

5. Circuit hypoxia5. Circuit hypoxia

6. 6. Halocarbon Halocarbon overdoseoverdose

7. Hypovolemia7. Hypovolemia

8. Pneumothorax8. Pneumothorax

9. Air Embolism9. Air Embolism

10. Hyperthermia10. Hyperthermia

11. Aspiration11. Aspiration

12. 12. Acid-base Acid-base imbalanceimbalance

13. 13. Cardiac dysrhythmiasCardiac dysrhythmias

14.14. IV drug overdose IV drug overdose

Source: Barash Handbook Source: Barash Handbook

These mishaps …

Detecting Mishaps with Detecting Mishaps with MonitorsMonitors

Pulse oximeterPulse oximeter Mass spectrometerMass spectrometer CapnographCapnograph Automatic BPAutomatic BP StethoscopeStethoscope SpirometerSpirometer Oxygen analyzerOxygen analyzer EKGEKG TemperatureTemperature

1,2,3,4,5,8,9,11,141,2,3,4,5,8,9,11,14

1,2,3,6,9,10,121,2,3,6,9,10,12

1,2,3,9,10,121,2,3,9,10,12

6,7,9,146,7,9,14

1,3,4,131,3,4,13

1,21,2

55

131310 10 Source: Source: Barash Barash

Handbook Handbook

… are detected using these monitors

Basic MonitoringBasic Monitoring Cardiac: Blood Pressure, Heart Rate, ECGCardiac: Blood Pressure, Heart Rate, ECG ECG: Rate, ST Segment (ischemia), Rhythm ECG: Rate, ST Segment (ischemia), Rhythm Respiratory: Airway Pressure, Capnogram, Pulse Respiratory: Airway Pressure, Capnogram, Pulse

Oximeter, Spirometry, Visual CuesOximeter, Spirometry, Visual Cues Temperature Temperature [pharyngeal, axillary, esophageal, etc.][pharyngeal, axillary, esophageal, etc.]

Urine output (if Foley catheter has been placed)Urine output (if Foley catheter has been placed) Nerve stimulator [face, forearm] Nerve stimulator [face, forearm] (if relaxants used)(if relaxants used)

ETT cuff pressure (keep < 20 cm HETT cuff pressure (keep < 20 cm H22O)O)

Auscultation Auscultation (esophageal or precordial stethoscope)(esophageal or precordial stethoscope)

Visual surveillance of the anesthesia workspace Visual surveillance of the anesthesia workspace

and some exposed portion of the patientand some exposed portion of the patient

Visual SurveillanceVisual Surveillance Anesthesia machine / workspace checkoutAnesthesia machine / workspace checkout Patient monitor numbers and waveformsPatient monitor numbers and waveforms Bleeding/coagulation Bleeding/coagulation (e.g., are the surgeons (e.g., are the surgeons

using a lot of suction or sponges? )using a lot of suction or sponges? ) Diaphoresis / movements / grimacesDiaphoresis / movements / grimaces Line quality Line quality (is my IV reliable?)(is my IV reliable?) Positioning safety reviewPositioning safety review Respiratory pattern Respiratory pattern (e.g. tracheal tug, (e.g. tracheal tug,

accessory muscle use etc.)accessory muscle use etc.)

Low Tech Patient Low Tech Patient MonitoringMonitoring

Manual blood pressure cuffManual blood pressure cuff Finger on the pulse and foreheadFinger on the pulse and forehead Monaural stethoscope Monaural stethoscope

(heart and breath sounds)(heart and breath sounds) Eye on the rebreathing bag Eye on the rebreathing bag (spontaneously (spontaneously

breathing patient)breathing patient) Watch respiratory patternWatch respiratory pattern Watch for undesired movementsWatch for undesired movements Look at the patient’s faceLook at the patient’s face

color OK? color OK? diaphoresis present?diaphoresis present? pupilspupils

High Tech Patient High Tech Patient MonitoringMonitoring

Examples of Multiparameter Patient MonitorsExamples of Multiparameter Patient Monitors

High Tech Patient High Tech Patient MonitoringMonitoring

Some Specialized Patient MonitorsSome Specialized Patient Monitors

Depth of Anesthesia Monitor

Evoked Potential Monitor

Transesophageal Echocardiography

Special MonitoringSpecial Monitoring Pulmonary artery lines (Swan Ganz)Pulmonary artery lines (Swan Ganz) Transesophageal echocardiographyTransesophageal echocardiography Intracranial pressure (ICP) monitoringIntracranial pressure (ICP) monitoring Electrophysiological CNS monitoringElectrophysiological CNS monitoring Renal function monitoring (indices)Renal function monitoring (indices) Coagulation monitoring (e.g. ACT)Coagulation monitoring (e.g. ACT) Acid-base monitoring (ABGs)Acid-base monitoring (ABGs) Monitoring depth of anesthesiaMonitoring depth of anesthesia

AlarmsAlarms Purpose:Purpose: Alarms serve to alert Alarms serve to alert

equipment operators that some equipment operators that some monitored variable or combination monitored variable or combination of variables is outside some regionof variables is outside some region

Motivation:Motivation: recognition of limited recognition of limited attentiveness capability in humans, attentiveness capability in humans, even under good operating even under good operating conditionsconditions

8 Axes of Clinical Anesthesia 8 Axes of Clinical Anesthesia Monitoring Monitoring

(A Conceptual Model)(A Conceptual Model) Axis I - Airway /RespiratoryAxis I - Airway /Respiratory Axis II - Circulatory / VolumeAxis II - Circulatory / Volume Axis III - Depth of AnesthesiaAxis III - Depth of Anesthesia Axis IV - NeurologicalAxis IV - Neurological Axis V - Muscle RelaxationAxis V - Muscle Relaxation Axis VI - TemperatureAxis VI - Temperature Axis VII - Electrolytes / MetabolicAxis VII - Electrolytes / Metabolic Axis VIII - CoagulationAxis VIII - Coagulation

Airway / Respiratory Airway / Respiratory AxisAxis

Correct ETT placementCorrect ETT placement ETT cuff pressureETT cuff pressure Airway pressureAirway pressure OxygenationOxygenation VentilationVentilation SpirometrySpirometry Pulmonary biomechanicsPulmonary biomechanics Airway gas monitoringAirway gas monitoring Clinical: Clinical: wheezing, crackles, equal air entry, wheezing, crackles, equal air entry,

color, respiratory pattern (rate, rhythm, depth, color, respiratory pattern (rate, rhythm, depth, etc.)etc.)

Circulatory AxisCirculatory Axis Cardiac outputCardiac output Input pressures (CVP, LAP)Input pressures (CVP, LAP) Output pressures (BP, PAP)Output pressures (BP, PAP) Pacemaker: rate, conductionPacemaker: rate, conduction Cardiac contractilityCardiac contractility Vascular resistances (SVR, PVR)Vascular resistances (SVR, PVR) Intracardiac shuntsIntracardiac shunts

Cardiac Monitoring Cardiac Monitoring MethodsMethods

Symptoms and signs: Symptoms and signs: eg, angina, diaphoresis, eg, angina, diaphoresis,

mental statemental state Finger on the pulse:Finger on the pulse: rate, rhythm, pulse “volume” rate, rhythm, pulse “volume”

Auscultation: Auscultation: rate, rhythm, murmurs, extra soundsrate, rhythm, murmurs, extra sounds

ElectrocardiogramElectrocardiogram: rate, rhythm, ischemia: rate, rhythm, ischemia Pulse oximeter waveform: Pulse oximeter waveform: rate, rhythmrate, rhythm Blood pressure: Blood pressure: cuff, oscillotonometry, art. linecuff, oscillotonometry, art. line

Volume Status: Volume Status: low-tech, high-techlow-tech, high-tech

Depth of Depth of Anesthesia Anesthesia

Clinical SignsClinical Signs eye signseye signs

respiratory signsrespiratory signs

cardiovascular signscardiovascular signs

CNS signsCNS signs

EEG monitoringEEG monitoring

Facial EMG monitoring Facial EMG monitoring

(experimental)(experimental)

Esophageal contractility (obsolete)Esophageal contractility (obsolete)

CNS MonitoringCNS Monitoring Clinical: Clinical: sensorium, reflexes, “wake up test”sensorium, reflexes, “wake up test” Electroencephalography: Electroencephalography: raw EEG, compressed raw EEG, compressed

spectral arrays (CSA), 95% spectral edge, etc.spectral arrays (CSA), 95% spectral edge, etc. Evoked potentialsEvoked potentials (esp. somatosensory EPs) (esp. somatosensory EPs) Monitoring for venous air emboliMonitoring for venous air emboli Intracranial pressure (ICP) monitoringIntracranial pressure (ICP) monitoring Transcranial doppler studiesTranscranial doppler studies

(MCA flow velocity) (MCA flow velocity) (Research)(Research) Jugular bulb saturation Jugular bulb saturation (Research)(Research) Cerebral oximetry Cerebral oximetry (Research)(Research)

Relaxation AxisRelaxation Axis Clinical Signs +/- Nerve Clinical Signs +/- Nerve

StimulatorStimulator MechanomyographyMechanomyography ElectromyographyElectromyography Piezoelectric methodsPiezoelectric methods Special methods (e.g. DBS)Special methods (e.g. DBS)

Temperature MonitoringTemperature MonitoringRationale for useRationale for use detect/prevent hypothermiadetect/prevent hypothermia monitor deliberate hypothermia monitor deliberate hypothermia adjunct to diagnosing MHadjunct to diagnosing MH monitoring CPB cooling/rewarmingmonitoring CPB cooling/rewarming

SitesSites EsophagealEsophageal NasopharyngealNasopharyngeal AxillaryAxillary RectalRectal BladderBladder

Electrolyte / Metabolic Electrolyte / Metabolic AxisAxis

Fluid balanceFluid balance SugarSugar ElectrolytesElectrolytes Acid-base balanceAcid-base balance Nutritional statusNutritional status

Coagulation MonitoringCoagulation Monitoring

Clinical signsClinical signs PT / PTT / INRPT / PTT / INR ACTACT Platelet countsPlatelet counts Factor assays Factor assays TEGTEG

The EndThe End