Monitoring is a human right.Monitoring is a human right. Anesthetist relies on his/her Anesthetist relies on his/her

natural senses to monitor the natural senses to monitor the patient.patient.

Simple aids as stethoscope & Simple aids as stethoscope & sphygmomanometer help the sphygmomanometer help the anesthetist and may safe the anesthetist and may safe the patient.patient.

Although the anesthetist is Although the anesthetist is generally careful, conscious generally careful, conscious and informed, he is usually and informed, he is usually blamed if a patient dies blamed if a patient dies during during or shortly afteror shortly after operation. operation.

However, inappropriate use of However, inappropriate use of monitor may confuse or monitor may confuse or mislead the anesthetist or mislead the anesthetist or distracting him by distracting him by malfunctioning device. malfunctioning device.

At the same time, if the patient At the same time, if the patient dies during anesthesia and he dies during anesthesia and he was unattached to an available was unattached to an available monitoring device, the monitoring device, the anesthetist is legally anesthetist is legally indefensibleindefensible..

This is because the concept This is because the concept that, patients who suffer as a that, patients who suffer as a result of negligence should be result of negligence should be compensated.compensated.

So, it is important to use So, it is important to use monitor formonitor for::

Safety.Safety. Conduct of anesthesia.Conduct of anesthesia. ICU practice. ICU practice. Research work.Research work. Assessment of critical Assessment of critical

conditions. conditions.

Monitor is a Latin word Monitor is a Latin word “monere”“monere” which means which means “to “to warn”warn”

Any monitor consists of:Any monitor consists of:

1)1) Sensor.Sensor.

2)2) System for data collection.System for data collection.

3)3) System for interpretation.System for interpretation.

Simple classification of Simple classification of monitoring devicesmonitoring devices

Class sensor data collect. Class sensor data collect. interpret. interpret.

I Human Human I Human Human Human Human

II Device Human II Device Human Human Human

III Device Device III Device Device Human Human

IV Device Device IV Device Device Device Device

Degree of invasiveness of Degree of invasiveness of monitoringmonitoring

Non invasive e.g. ECGNon invasive e.g. ECG Minimally invasive e.g. I.V Minimally invasive e.g. I.V

cannula cannula Penetrating e.g. ECHOPenetrating e.g. ECHO Invasive e.g. Arterial Invasive e.g. Arterial

cannula cannula Highly invasive e.g. Brain, Highly invasive e.g. Brain,

heart cannulaheart cannula

Limitation of monitoringLimitation of monitoring

1)1) Delay.Delay.

2)2) Danger.Danger.

3)3) Decrease skill.Decrease skill.

4)4) Doubt of results.Doubt of results.

5)5) Distracting set up.Distracting set up.

How to select monitorHow to select monitor

Depend on Depend on

1)1) Aim.Aim.

2)2) Experience.Experience.

3)3) Type of anesthesia.Type of anesthesia.

4)4) Facilities & availability. Facilities & availability.

5)5) Nature of surgery.Nature of surgery.

6)6) General condition of the General condition of the patient.patient.

CVS monitorsCVS monitors Peripheral pulse.Peripheral pulse. Tissue perfusion.Tissue perfusion. ECG.ECG. Arterial blood pressure.Arterial blood pressure. Central venous catheterizationCentral venous catheterization Pulmonary artery catheterization.Pulmonary artery catheterization. Cardiac output measurement.Cardiac output measurement. TEE.TEE. Blood loss measurement.Blood loss measurement.

Respiratory system Respiratory system monitorsmonitors Clinical monitors.Clinical monitors.

Airway pressure measurement.Airway pressure measurement. Disconnection alarm.Disconnection alarm. Stethoscope (pericordial & Stethoscope (pericordial &

esophegeal).esophegeal). Spirometery.Spirometery. O2 monitoring.O2 monitoring. Co2 monitoring.Co2 monitoring. Anesthetic gas analysis.Anesthetic gas analysis. H+ ions measurement.H+ ions measurement.

CNS monitorsCNS monitors

Clinical monitoring.Clinical monitoring. EEG.EEG. Evoked potentials.Evoked potentials. Cranial nerve monitoring.Cranial nerve monitoring. Cerebral blood flow measurement.Cerebral blood flow measurement. Monitoring of cerebral Monitoring of cerebral

oxygenation.oxygenation. Monitoring of depth of anesthesia.Monitoring of depth of anesthesia.

Monitoring of Monitoring of metabolismmetabolism

Temperature monitoring.Temperature monitoring. Tissue oxygenation monitoring.Tissue oxygenation monitoring. Indirect calorimetry.Indirect calorimetry. Fluid & electrolyte status Fluid & electrolyte status

monitoring.monitoring. Blood gases & acid base status Blood gases & acid base status

monitoring.monitoring. Hormonal status monitoring.Hormonal status monitoring.

Neuromuscular Neuromuscular monitoringmonitoring

Clinical tests:Clinical tests:1)1) Conscious patient.Conscious patient.

2)2) Un Conscious patient.Un Conscious patient.

Peripheral nerve stimulation:Peripheral nerve stimulation:1)1) Single twitch.Single twitch.

2)2) Train of four twitches.Train of four twitches.

3)3) Tetanic stimulation.Tetanic stimulation.

4)4) Double burst stimulation.Double burst stimulation.

Blood pressure monitorsBlood pressure monitors

ABP= CO×SPRABP= CO×SPR MAP= Diastolic BP + 1/3 Pulse MAP= Diastolic BP + 1/3 Pulse

pressurepressure Pressure units:Pressure units:

mmHg (torr) & Kpa & cm H2OmmHg (torr) & Kpa & cm H2O

(7.6 mmHg= 1 Kpa = 10 cmH2O)(7.6 mmHg= 1 Kpa = 10 cmH2O)

ABP measurementABP measurement

Non invasive BP Non invasive BP monitoring:monitoring:

Palpation methode.Palpation methode. Auscultation methode.Auscultation methode. Doppler (U/S) probe.Doppler (U/S) probe. Oscillometry.Oscillometry. Plethysmography (finapress).Plethysmography (finapress). Arterial tonometry.Arterial tonometry.

Invasive BP monitoring:Invasive BP monitoring:

* Indications:* Indications:

* Contraindications:* Contraindications:

* Technique:* Technique:

- selection of artery:- selection of artery:

By (allen & modified allen tests).By (allen & modified allen tests).

- cannulation technique:- cannulation technique:

- transducer zeroing: - transducer zeroing:

Complications of arterial Complications of arterial cannulationcannulation

Hematoma.Hematoma. Vasospasm.Vasospasm. Thrombosis.Thrombosis. Embolization of air or thrombus.Embolization of air or thrombus. Skin necrosis, infection…..Skin necrosis, infection….. Nerve damage.Nerve damage. Disconnection and fatal blood Disconnection and fatal blood

loss…..loss…..

OO2 monitoring2 monitoring

(1) Monitor O2 delivery to (1) Monitor O2 delivery to the patient:the patient:

O2 failure alarm.O2 failure alarm. O2 conc. In the gas mixture:O2 conc. In the gas mixture:

* Fuel cell.* Fuel cell.

* Clark electrode.* Clark electrode.

* Paramagnetic analyzer.* Paramagnetic analyzer.

(2) Monitor O2 delivery to the (2) Monitor O2 delivery to the tissuestissues

A: Global tissue oxygenation:A: Global tissue oxygenation:

1- clinical monitoring e.g. 1- clinical monitoring e.g.

cap. refilling, state of cap. refilling, state of extremities…extremities…

2- O2 transport monitoring through 2- O2 transport monitoring through measurement of:measurement of:

COP & Hb level & SaO2 & PaO2COP & Hb level & SaO2 & PaO2

3- O2 uptake monitoring 3- O2 uptake monitoring through:through:

* measurement of: SvˉO2 by * measurement of: SvˉO2 by pulmonary artery pulmonary artery oximetry.oximetry.

* serum lactic acid level.* serum lactic acid level.

(B) Regional tissue (B) Regional tissue oxygenation:oxygenation:

1- Oximetry: * subcutaneous1- Oximetry: * subcutaneous

* intravenous* intravenous

* cerebral * cerebral

2- Tonomitry : 2- Tonomitry :

gastric intraluminal gastric intraluminal tonometry. tonometry.

Value:Value:

1- O2 saturation of arterial blood.1- O2 saturation of arterial blood.

2- Heart rate.2- Heart rate.

3- Tissue perfusion.3- Tissue perfusion.

PrinciplesPrinciples::

Pulse oximeter probe consists Pulse oximeter probe consists of:of:

- Photosensor.Photosensor.- Photodetector.Photodetector.

Based on transmission Based on transmission spectrophotometry & spectrophotometry & plethysmography. plethysmography.

A- Spectrophotometry:A- Spectrophotometry:

According to (Lambert-bear Law)According to (Lambert-bear Law)

oxy- & reduced Hb differs in oxy- & reduced Hb differs in their absorption of red & their absorption of red & infrared light.infrared light.

Analyzing these changes of light Analyzing these changes of light absorption by microprocessor absorption by microprocessor can identify the value of O2 can identify the value of O2 saturation.saturation.

%saturation =%saturation =

oxy-Hb /(oxy-Hb +reduced-oxy-Hb /(oxy-Hb +reduced-Hb) × 100 Hb) × 100

B- Plethysmography:B- Plethysmography:

(SpO2) Used to identify arterial (SpO2) Used to identify arterial pulsation to avoid measuring O2 pulsation to avoid measuring O2 sat. in non-pulsating blood of sat. in non-pulsating blood of viens & tissues.viens & tissues.

DisadvantagesDisadvantages:: InaccuracyInaccuracy…….if O2 sat less than …….if O2 sat less than

70%70% InsensitivityInsensitivity …..significant …..significant

decrease in PaO2 before decrease in PaO2 before significant decrease in SaO2 is significant decrease in SaO2 is detected.detected.

InterferenceInterference…..…..• Intrinsic e.g. co-Hb, Met-Hb, I.V Intrinsic e.g. co-Hb, Met-Hb, I.V

dyes, bilirubine, fetal Hb……dyes, bilirubine, fetal Hb……• Extrinsic e.g. motion, cautery, Extrinsic e.g. motion, cautery,

nail bed infection, polish……nail bed infection, polish……

CO2 monitoringCO2 monitoring

A- Excretion of CO2 in the tissues A- Excretion of CO2 in the tissues by:by:

1- CO2 (severinghaus) 1- CO2 (severinghaus) Elctrode.Elctrode.

2-Transcutaneous partial 2-Transcutaneous partial pressure of CO2pressure of CO2

B- Excretion of CO2 in the expired B- Excretion of CO2 in the expired gas by:gas by:

Capnography.Capnography.

Value:Value:

1- Confirm adequate ventilation.1- Confirm adequate ventilation.

2- Detect esophegeal intubation.2- Detect esophegeal intubation.

3- Maintain normocapnia.3- Maintain normocapnia.

4- Indicate quality of perfusion.4- Indicate quality of perfusion.

5- Diagnosis of air embolism, res. 5- Diagnosis of air embolism, res. Obstruction, arrest & quality of Obstruction, arrest & quality of resustation………resustation………

6- Prediction of awareness, 6- Prediction of awareness, recovery from MR.recovery from MR.

7- Assessment of inspiratory valve 7- Assessment of inspiratory valve incompetence…incompetence…

Principles:Principles: Based on infrared absorption Based on infrared absorption

spectrophotometery as CO2 spectrophotometery as CO2 absorb light strongly at 4260 nm.absorb light strongly at 4260 nm.

Types:Types:

1- Main stream capnography1- Main stream capnography

(Flow through)(Flow through)

2- Side stream capnography2- Side stream capnography

(Aspiration)(Aspiration)

Definition:Definition:Simply, hypoxia means decreased O2 any where; air, blood or tissue.

Hypoxemia is the reduction of O2 in the blood resulting in:

* PaO2 is < 60 mmHg or* SaO2 is < 90 %

Mean PaO2 = Mean PaO2 =

102 – 0.33 (age in years) ± 10 102 – 0.33 (age in years) ± 10 mmHg (SD)mmHg (SD)

It is an old equation by Marshall It is an old equation by Marshall and Whyche in, 1972and Whyche in, 1972

These measures must be:These measures must be:

- At rest - At rest - Breathing room air - Breathing room air

NB:NB: Neonates hypoxemia occurs Neonates hypoxemia occurs when:when:

- PaO2 is < 50 mmHg- PaO2 is < 50 mmHg- SaO2 is < 88 %- SaO2 is < 88 %

With age there is progressive With age there is progressive decline of PaO2decline of PaO2

That is to say subtracting 1 That is to say subtracting 1 mmHg from the minimal PaO2 mmHg from the minimal PaO2 for adult (80 mmHg) for every for adult (80 mmHg) for every year over 60 years of age.year over 60 years of age.

Types of HypoxiaTypes of Hypoxia1- Hypoxic hypoxia:1- Hypoxic hypoxia:

When FiO2 < 0.21When FiO2 < 0.21 Hypoventilation.Hypoventilation. Pulmonary V/Q mismatch.Pulmonary V/Q mismatch. Rt to Lt shunt.Rt to Lt shunt.

2- Circulatory Hypoxia2- Circulatory HypoxiaDue to reduced COP.

3- Demand Hypoxia3- Demand Hypoxia Due to increased O2 utilization.

4- Hemic Hypoxia4- Hemic HypoxiaDue to:Due to:

decreased Hb content.decreased Hb content.

decreased Hb function.decreased Hb function.

5- Histotoxic Hypoxia5- Histotoxic Hypoxia Due to inability of cells to Due to inability of cells to

utilize O2utilize O2

e.g. cyanide toxicity.e.g. cyanide toxicity.

C/P of Hypoxemia:C/P of Hypoxemia:

1- Cyanosis.1- Cyanosis.2- Sympathetic stimulation in form of:2- Sympathetic stimulation in form of:

tachycardia (except….?)tachycardia (except….?) hypertension (except….?)hypertension (except….?) sweating, arrhythmias, agitation,sweating, arrhythmias, agitation,

….….

3- Arrest….in sever persistent 3- Arrest….in sever persistent hypoxia.hypoxia.

4- + C/P of the cause.4- + C/P of the cause.

Prevention and management:Prevention and management:

# Prediction from history, exam., # Prediction from history, exam., investig……investig……

To detect the predisposing factors e.g.To detect the predisposing factors e.g. 1- Type & site of the surgery….1- Type & site of the surgery…. 2- Respiratory diseases…..2- Respiratory diseases….. 3- Smoking3- Smoking 4- Obesity4- Obesity 5- Pregnancy5- Pregnancy 6- Age…..6- Age…..

# To do # To do what ? ?.........................what ? ?.........................

Good monitoring.Good monitoring. Treatment of the cause.Treatment of the cause. Sterile equipment.Sterile equipment. Humidified gases.Humidified gases. Adequate reversal of NMB.Adequate reversal of NMB. Proper postoperative analgesia, Proper postoperative analgesia,

physiotherapy.physiotherapy.

# Continue postoperative # Continue postoperative oxygenation, reintubation, oxygenation, reintubation, mechanical ventilation may be mechanical ventilation may be indicated unfortunately in sever indicated unfortunately in sever cases.cases.

The following information is The following information is obtained Saturday, March 29, obtained Saturday, March 29, 2008 about2008 about

2121--year-old Dawn Marie Mackyear-old Dawn Marie Mack

Dawn had an abortion performed Dawn had an abortion performed at National Abortion Federation at National Abortion Federation member of Eastern Women's member of Eastern Women's Center. She was attend, but Center. She was attend, but Dawn went into cardiorespiratory Dawn went into cardiorespiratory arrestarrest..

The suit said that Eastern staff The suit said that Eastern staff failed to adequately respond to failed to adequately respond to "the precipitous drop in "the precipitous drop in Plaintiff's blood pressure, cardiac Plaintiff's blood pressure, cardiac arrhythmia leading to cardiac arrhythmia leading to cardiac arrest and cessation of arrest and cessation of

respirationrespiration".".

Dawn was transported to a Dawn was transported to a hospital by ambulance, where hospital by ambulance, where staff tried to resuscitate Dawn staff tried to resuscitate Dawn but, She diedbut, She died..

The suit contended that the The suit contended that the following shortcomings caused following shortcomings caused Dawn's deathDawn's death::

* *carelessness in hiring staffcarelessness in hiring staff

* *negligent supervising of staffnegligent supervising of staff

* *lack of emergency protocol and lack of emergency protocol and staff skilled in treating staff skilled in treating

emergenciesemergencies

* *lack of adequate equipmentlack of adequate equipment

* *failure to maintain equipment failure to maintain equipment appropriatelyappropriately

* *failure to administer timely and failure to administer timely and properly dosed medicationsproperly dosed medications

* *failure to convey to Dawn the failure to convey to Dawn the risks of anesthesiarisks of anesthesia

* *failure to adequately evaluate failure to adequately evaluate Dawn's condition via exam and Dawn's condition via exam and medical history prior to medical history prior to anesthesiaanesthesia

* *failure to allow sufficient time to failure to allow sufficient time to administer anesthesia and administer anesthesia and perform the abortion in a safe perform the abortion in a safe and careful mannerand careful manner

* *inadequate staff traininginadequate staff training

* * failure to adequately failure to adequately monitor monitor anesthesiaanesthesia

* * failure to accurately chart and failure to accurately chart and record observations and responsesrecord observations and responses

* * failure to anticipate potential failure to anticipate potential complicationscomplications

So, whatSo, what! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !