INTRA OPERATIVE MONITORING BY VAISHALI SYAL MAM
INTRA-OPERATIVE MONITORING
Nedtronic
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Ovili
1.0
231 WV
2 Orbiculars Oils
41 V
100 W
Franla
101
Vol
NIM-Response 3.0
Intraoperative monitoring :
• A technique that is directly aimed at monitoring of vitals and reducing the risk of a patient
▪ Most important part of anesthesia to prevent complications
▪ Basic Monitoring (Clinical)
▪ Advanced Monitoring (Instrumental)
▪ Oxygenation
▪ Ventilation
▪ Circulation
▪ Temperature
▪ Urine Output
▪ ECG
▪ NIBP
▪ IBP
▪ CVP
▪ Capnography
▪ PA Catheterisation
▪ Used to monitor the actual value of oxygen delivered to the patient
- both inspired and expired.
▪ Essential during anesthesia while delivering gases (medical air, volatile anesthetic agents).
PULSE OXIMETER
99 - 82
▪ First used by - Lambert-Beer Law
▪ Is a non-invasive way to monitor oxygenation of a
patient’s Hb - using light.
▪ Most common monitoring used in anesthesia to
monitor saturation of patient’s Hb with oxygen.
▪ Normal range : 97-100%
Principle of Pulse Oximetry
A sensor with both red and infra red light at wavelength 660nm(red) and 940nm(infrared) passes through the tissue containing blood
While absorption of both wavelengths by the blood is measured and oxygen saturation can be calculated.
FRACTIONAL
▪ Oxyhaemoglobin
▪ Arterial Oxygen Saturation
▪ Arterial blood sample
FUNCTIONAL
▪ Oxyhemoglobin (oxyhemoglobin+deoxyhemoglobin)
▪ Anemia : severe anemia →under-estimation of actual values.
▪ Nail polish (blue color) shows false reading
▪ Shivering : constant movement of finger shows false reading.
▪ Skin pigmentation
▪ Dyes: e.g. methylene blue or green.
▪ Hypovolemia and vasoconstriction - in cold temperature
▪ Capnography : monitoring of the concentration or partial pressure of CO2 in the respiratory gases
▪ Used in all anaesthesia & intensive care to monitor the inhaled & exhaled concentration of CO2
▪ CO2 monitoring - basic standard for all patients receiving GA - as suggested by ASA guidelines.
Capnography Waveform Patterns
Normal
_
45
.
Hyperventilation
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Hypoventilation
45+
Bronchospasm
_
▪ Capnometry : measurement and numeric representation
of CO2 concenteration or partial pressure in respiratory
gases during inspiration and expiration.
▪ Capnogram : time of CO2 concentration.
▪ Capnography : continuous monitoring of CO2 during the
respiratory cycle.
▪ Works on the principle that CO2 absorbs infrared radiations.
▪ A beam of infrared light is passed across the gas sample to fall on a sensor.
▪ The presence of CO2 in the gas leads to a reduction in the amount of light falling on the sensor which changes the voltage in a circuit
▪ Information about CO2 production,
(pulmonary perfusion)
▪ Alveolar ventilation
▪ Respiratory patterns
▪ Elimination of CO2 from breathing circuits and
ventilators
▪ During anaesthesia, there is interplay between two components i.e the patient and the anaesthesia administration devices
▪ The critical connection between the two components is either on ET tube or a mask and CO2 analyser
▪ Capnography directly reflects the elimination of CO2 by the lungs to the anaesthesia device & indirectly it reflects the production of CO2 by tissues & the circulatory transport of CO2 to the lungs
▪ Use of Capnography as Emergency Medical Service (EMS) is assessment & treatment of patient in the free hospital environment
▪ It is used to verify & monitoring the position of an ET tube or blind insertion of airway device in EMS
▪ Also used to measure cardiac output (study by AHA)
▪ Side stream capnometers
▪ Sample tubing connected to an airway that continually aspirates respiratory gases at a rate of 50 to 400 ml/min. Advantages :
▪ Accurate capnography when attached as close as possible to the patient.
▪ Light weight
▪ Used to measure CO2 and anesthetic gases. Diadvantages :
▪ Condensation of humidified gases
▪ Delay in measurement
▪ Directly attached to the airway side.
Advantages :
▪ Fast response time
Disadvantage :
▪ Bulky equipment placed directly in ET tube.
▪ Anesthetic gases not allowed to measure.
Mainstream and Sidestream
CAPNOSTAT®3 Mainstream CO, Sensor
LoFlow Sidestream CO, Module
ZOLL
Advancing Resuscitation. Today.
▪ An electrocardiogram( EKG or ECG ) is a test that checks the
problems with the electrical activity of heart
▪ Electrical activity of heart is tracing on ECG paper
▪ 12 standard leads represent the hearts electrical activity and
recorded by electrodes on the body surface
• P wave :- sequental activation (depolarization) of the right &
left atria
▪ QRS complex :- right & left ventricular depolarization
( normally the ventricles are activated simultaneously)
▪ S T-T wave :- shows ventricular repolarisation
▪ U wave :- origin for this wave is not clear but probably
represents after depolarisation in the ventricles
1. PR interval:- time interval from onset of arterial
depolarisation (P wave) to onset of ventricular depolarisation ( QRS complex).
2. QRS duration:- shows duration of ventricular muscle
depolarisation
3. QT interval :- shows duration of ventricular depolarisation &
repolarisation
4. PR interval :- shows duration of ventricular cardiac cycle
5. PP interval:- shows duration of atrial cycle or rate
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IMAGE OF ECG INTERVALS
Time
Voltage
-1 mV
RR Interval
0.2 sec
QRS Complex
0.04 sec
T Wave ST Segment
U Wave
P Wave
-PR
QRS:
QT
▪ Is an oscillometric method used for determining mean arterial pressure, systolic and diastolic pressure.
▪ Arterial pulsations cause oscillations in cuff pressure. These oscillations are small if the cuff is inflated above systolic pressure.
▪ A micro-processor is used to derive systolic, mean, and diastolic pressures .
▪ Expel all air from BP cuff before taking a measurement
▪ Residual air can lead to inaccurate readings caused by a lose fitting cuff
▪ Apply cuff around extremity put one finger beneath the cuff
▪ Check lose connections to both sides (cuff & monitor side)
▪ Do not place an NIBP cuff on the same extremity where an infusion line is located.
( it will impede I.V. flow)
▪ Do not place NIBP on the same extremity where SpO2 is being monitored. (it will interfere with the continuous monitoring of pulse oximetry and cause the monitor to alarm)
▪ IBP :- commonly used technique in ICU & operation theatre.
▪ This technique involves direct measurement of arterial pressure by inserting a cannula in a suitable artery
(commonly radial /femoral artery is preferred).
▪ CVP:- It is the blood pressure in the vena cava near the right atrium of the heart.
▪ It reflects blood returning to the heart and ability of the heart to pump the blood back into the arterial system .
▪ Normally CVP can be measured from two points
▪ Sternum:- 0 -14 cm H2O
▪ Midaxillary line: 8-15 cm H2O
▪ CVP can be measured by connecting the central venous catheter by the special infusion sets (digital-transducer)
▪ Cardiac tamponade
▪ Decreased cardiac output
▪ Forced exhalation
▪ Heart failure
▪ Hypovolemia
▪ Mechanical ventilation
▪ Pleural effusion
▪ Pulmonary embolism
▪ Pulmonary hypertension
▪ Deep inhalation
▪ Distributive shock (hypoperfusion in small vessels eg Septic shock}
▪ Hypervolaemia
▪ Used for early diagnosis of hypothermia
▪ A temperature probe(using a thermistor or a thermocouple) can be inserted at various sites, like o Tympanic membrane o Skin o Bladder o Oesophagus o Rectum o nasopharynx
▪ Urinary bladder catheterisation is the only reliable method of monitoring.
▪ Indicated in patients with congestive heart failure, renal failure, hepatic disease and shock.
▪ Lengthy surgeries and intraoperative diuretic administration are other indications
▪ Should be done with utmost care to in patients with high risk of infection.
▪ Infused fluid monitoring
▪ Bispectral index monitoring
▪ Entropy monitoring
Thank you
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