Cardiovascular Monitoring

Presenter: Dr. Rashmit ShresthaModerator : Dr. Dipesh Man Singh

Introduction Although electronic devices constitute crucially important, the physician’s sense offer an integrated, panoramic view of the patient’s conditions

Inspection, Palpation and Auscultation are the cornerstones of the physical examination, they are also fundamental to perioperative CV monitor

STETHOSCOPEIt provides simple and reliable means of continuous monitoring of heart and breath sound.

Esophageal stethoscope facilitates temperature, clear breath and heart sound.

Heart Rate (HR) Monitoring

• The ECG is the most common method used in the OR.

• Accurate detection of the R wave and measurement of R-R wave interval serve as the basis from which digitally displayed values are derived and periodically updated.

Pulse Rate (PR) MonitoringHR from ECG tracePR from pulse oximeter plethysmograph or arterial blood pressure monitor.

Pulse Deficit = PR < HRSeen in Atrial Fibrillation, electromechanical dissociation or pulseless electrical activity ( e.g. cardiac tamponade, extreme hypovolemia).

Arterial Blood Pressure Monitoring

• A. Indirect Cuff Devices

• B. Direct Arterial Cannulation

Indirect measurement of Arterial BP

• Sphygmomanometer, first described by Riva Rocci in 1896.

• Arm encircling inflatable elastic cuff

• Rubber bulb to inflate the cuff pressure

• Radial artery palpated as pressure increased in cuff

• Mercury manometer.• Identifying ONLY systolic

blood pressure !

• Detecting both systolic and diastolic pressure became possible with the description of the auscultatory method of Blood Pressure measurement by Korotkoff in 1905.

Korotkoff sounds• Complex series of audible frequencies produced

by turbulent flow beyond the partially occluding cuff.

• Phase I : sound heard – systolic pressure• Phase II & III : sound character changes• Phase IV: becomes muffled• Phase V : absent • Diastolic Blood pressure at Phase IV & V

A well fitted cuff bladder that extends to 40% of arm circumference and 80% of length of the upper arm

Automated Intermittent Techniques• Automated noninvasive blood

pressure(NIBP) devices are standard equipment in most critical care settings because they provide frequent, regular pressure measurement, free the operator to perform other vital clinical duties, provide audible alarms, and can transfer data to a computerized information system.

Automated NIBP• Based on oscillometry

(Marey,1876) • Variation in cuff pressure

resulting from arterial pulsations during cuff deflation sensed by monitor

• Pressure at which peak amplitude of arterial pulsations occur, corresponds closely to direct measured MAP

• SBP and DBP are derived from proprietary formulas

• SBP and DBP are less reliable than MAP

Complications of NIBP Measurement• Pain• Petechiae and ecchymoses• Limb edema• Venous stasis and thrombophlebitis• Peripheral neuropathy• Compartment syndrome

Direct Measurement of Arterial BP• Indication for Arterial Cannulation– Continuous, real-time BP monitoring– Planned pharmacological or mechanical

cardiovascular manipulation– Repeated blood sampling– Failure or indirect arterial BP measurement – Supplementary diagnostic information from the

arterial waveform

Percutaneous Radial Artery Cannulation

• Radial artery(RA) is the most common site.

• Before attempting RA cannulation, assessment of the adequacy of collateral flow to the hand is performed by modified Allen test.

Allen’s test

Arterial line insertion

Alternative Arterial Pressure Monitoring Sites

• Ulnar artery• Brachial artery• Axillary arteryFemoral arteryLess commonly used:Dorsalis pedisPosterior tibialSuperficial temporal arteries

Complications of Direct Arterial Pressure Monitoring

• Distal Ischemia, pseudoaneurysm, arteriovenous fistula

• Hemorrhage• Arterial embolization• Infection• Peripheral neuropathy• Misinterpretation of data• Misuse of equipment.

Central Venous Pressure Monitoring• Indications for Central Venous CannulationCVP monitoringPulmonary artery catherterization and monitoringTransvenous cardiac pacingTemoporary hemodialysisDrug adminstration : Concentrated vasoactive drugs, hyperalimentation, chemotherapy etcRapid infusions of fluids Aspiration of air emboliInadequate peripheral intravenous accessSampling site for repeated blood testing

Central Venous Catheterization (Rt. IJV)

Atrial Fibrillation, absence of a wave, prominent c wave, preserved x and y

decent

Complications of Central Venous Pressure Monitorng

• Mechanical : – Vascular injury : arterial, venous, cardiac tamponade• Respiratory compromise :- Airway compression from hematoma, Pneumothorax• Nerve injury• Arrhythmias • Thromboembolism • Infections • Misinterpretation of data• Misuse of equipment

THANK YOU !

References1. Miller’s Anesthesia, 8th Edition, Cardiovascular monitoring,

page 1345-2. https://en.wikipedia.org/wiki/Korotkoff_sounds3. https://www.youtube.com/watch?v=8xpKr1t7YQE4. Morgan and Mikhail’s Clinical Anesthesia. 5th Editions.