Circulation (cardiovascular) monitoring The goal of monitoring the circulatory system is to ensure adequate blood flow to tissues during all anesthetic procedures. Subjective methods   palpation of peripheral pulse, palpation of the heart beat through the chest wall, auscultation of heart beat.    Use of stethoscope, or other audible heart sound monitor aids the anesthetist in assessing the "presence", "absence", "regularity" or "irregularity" of a patient’s heart beat.   Palpation provides a subjective feeling of "presence" or "absence"; "strong" or "weak"; "regular" or "irregular" peripheral pulse.    Assessing capillary refill time (CRT) provides a subjective assessment of tissue perfusion.  A prolonged CRT suggests poor tissue perfusion. Objective methods electrocardiography (ECG), monitoring of arterial blood pressure, cardiac output, and central venous pressures

Blood Pressure provides information regarding the adequacy of blood flow to the patient’s tissue. Pulse pressure is the difference between the systolic and diastolic pressures. MAP =(SBP+2DBP)÷3 Radial artery systolic pressure is usually greater than aortic systolic pressure because of its more distal location

1. Noninvasive Arterial Blood Pressure Monitoring Include.. Doppler ultrasound probe coupled with a pressure cuff and sphygmomanometer  Indications : The use of any anesthetic A noninvasive blood pressure measurement every 3 to 5 min is adequate in most cases. Contraindications: techniques that rely on a blood pressure cuff are best avoided in extremities with vascular abnormalities (eg, dialysis shunts) or with intravenous lines. impossible to monitor blood pressure in patients (eg, those who have burns) who have no accessible site from which the blood pressure can be safely recorded.

CONT……. The accuracy …….=proper cuff size . The cuff’s bladder should extend at least halfway around the extremity, and the width of the cuff should be 20% to 50% greater than the diameter of the extremity Even if the pressure is high, when the resistance is also high, flow can be low. Thus, arterial blood pressure should be viewed as an indicator—but not a measure—of organ perfusion.

2. Invasive Arterial Blood Pressure Monitoring Indications catheterization of an artery include induced current or anticipated hypotension or wide blood pressure deviations, end-organ disease necessitating precise beat-to-beat blood pressure regulation, and the need for multiple ABGor other blood analyses. Contraindications catheterization should be avoided in smaller end arteries lacking collateral blood flow or in extremities where there is a suspicion of preexisting vascular insufficiency

CONT….. 1. The radial artery is commonly cannulated because of its superficial location and substantial collateral flow Also,,,,,Femoral ….brachial…..ulnar…..dorsalis pedis…..axillary artery……. Complications of intraarterial monitoring include hematoma, bleeding (particularly with catheter tubing disconnections), vasospasm, arterial thrombosis, embolization of air bubbles or thrombi, pseudoaneurysm formation, necrosis of skin overlying the catheter, nerve damage , infection, necrosis of extremities or digits, and unintentional intraarterial drug injection.

ELECTROCARDIOGRAPHY(ECG) All patients should have intraoperative monitoring of their electrocardiogram (ECG). There are no contraindications.

CONT… ▸ 3 or 5 lead electrode system is used for ECG monitoring in operating room. ▸ The 3 lead system has electrodes positioned on the right arm, left arm & chest position (placed in the left anterior axillary line at the 5th intercostal space referred as V5). Lead 2 is usually monitored by this system. ▸ The 5 lead system adds a right leg & left leg electrodes which allows monitoring V1, V2, V3, AVR, AVF & V5.

CONT….. ▸ Identification of P waves in lead 2 & its association with QRS complex is useful to distinguish a sinus rhythm from other rhythms. ▸ Analysis of ST segment is used as an indicator of MI (depression: ischemia // elevation: infarction). ▸ Over 85% of ischemic event can be detected by monitoring ST segment of lead 2 & V5.

The ECG is a recording of the electrical potentials generated by myocardial cells. Its routine use allows arrhythmias, myocardial ischemia, conduction abnormalities, pacemaker malfunction, and electrolyte disturbances to be detected

CVP( CENTRAL VENOUS PRESSURE ) • This is measured by inserting a catheter via a central vein, usually the internal jugular or subclavian, so that its tip lies at the junction of the superior vena cava and right atrium. • It is then connected via a fluid-filled tube to a transducer that converts the pressure signal to an electrical signal • Then ,This is amplified and displayed as both a waveform and pressure

Cont……. . • Loss of circulating volume will reduce venous return to the heart, diastolic filling and preload, and be reflected as a low or falling CVP • CVP is usually monitored in operations during which there is the potential for major fluid shifts (e.g. prolonged abdominal surgery) or blood loss (e.g. major orthopaedic and trauma surgery). • CVP is driving force for filling RA + RV. • Central Venous Pressure (CVP): 1-10 mmHg

Cont…... Internal jugular vein Advantages • Internal jugular vein lies in groove between sternal and clavicular heads of sternocleidomastoid muscle , it’s lateral and slightly anterior to carotid artery So it is readily identifiable landmark • Short straight course to SVC . • Easy intra OP access for anesthesiologist at patient’s head • High success rate 90-99% Complications? Vascular injury,,,bleeding,,,,,pneumothorax

Cont…... Subclavian vein: • Easier to insert Vs IJV • Better patient comfort Vs IJV . • Higher Risk of pneumothorax 2% • External jugular: • Easy to cannulate if visible. • no risk of pneumothorax, • high risk of bleeding. • 20% : cannot access central circulation

Thanks a lot ... Sara AlZoubi