Week 11 Haemodynamic Monitoring PDF

Haemodynamic monitoring involves the Understanding Haemodynamic measurement of pressure, flow, and oxygenation within the cardiovascular...

Haemodynamic monitoring involves the Understanding Haemodynamic measurement of pressure, flow, and oxygenation within the cardiovascular Monitoring system. Haemodynamic monitoring can be divided into non-invasive and invasive methods: Mental status Heart rate, pulses, ECGs Blood pressure, capillary refill Types of Haemodynamic Non-Invasive Monitoring Monitoring Respiratory rate, pulse oximetry Urine output Body temperature, skin temperature Systemic arterial pressure monitoring Central venous pressure (CVP) monitoring Invasive Monitoring Pulmonary artery pressure monitoring Cardiac output monitoring The transducer must be levelled to the reference point of the phlebostatic axis (intersection of the fourth intercostal space and the mid-thoracic anterior– posterior diameter) Zeroing and Levelling the Transducer System Ensures accuracy of readings by exerting pressure on the transducer, called zero. Principles of Haemodynamic Monitoring Haemodynamic Accuracy A way of checking the dynamic response of the monitor to signals from the blood vessel Fast-Flush Square-Wave Testing Allows for checking the accuracy of subsequent haemodynamic pressure values Commonly placed in the radial artery, but can also be in the brachial, femoral, dorsalis pedis, and axillary arteries. Indicated when precise and continuous monitoring is required, especially in periods of fluid volume, cardiac output, and blood pressure instability. Invasive Intra-Arterial Pressure Monitoring Infection Arterial thrombosis Distal ischemia Complications Air embolism Accidental disconnection leading to rapid blood loss Accidental drug administration through the arterial catheter CVP is the pressure recorded from the right atrium or superior vena cava, representing the filling pressure of the right side of the heart. 0 to +8 mmHg CVP monitoring in the critically ill is established practice, but the traditional belief that CVP reflects ventricular preload and predicts fluid responsiveness has been challenged. Haemodynamic CVP represents the driving force for Monitoring filling the right atrium and ventricle. a = atrial contraction CVP Waveform Analysis c = closing and bulging of the tricuspid valve x = atrial relaxation, with downward movement of the tricuspid valve during ventricular contraction Central Venous Pressure (CVP) Monitoring v = passive filling of atrium (tricuspid valve still closed) y = ventricular filling with opening of the tricuspid valve Diagnosis of right ventricular infarction, right heart failure, tamponade, tricuspid regurgitation or stenosis, complete heart block, constrictive pericarditis, and differential diagnosis of shock state Uses of CVP Monitoring Correct central line placement Right ventricular failure Tricuspid stenosis or regurgitation Pericardial effusion or constrictive pericarditis Causes of Raised CVP Superior vena caval obstruction Fluid overload Hyperdynamic circulation High PEEP settings CVP should not be used in isolation to assess fluid responsiveness, as it has a very poor relationship with blood volume and is a poor predictor of the hemodynamic response to a fluid challenge. Limitations of CVP Interpretation of CVP should be in association with information relating to other haemodynamic variables. Dominant a wave - pulmonary hypertension, tricuspid stenosis, pulmonary stenosis Cannon a wave - complete heart block, ventricular tachycardia with atrio- ventricular dissociation Dominant v wave - tricuspid regurgitation Absent x descent - atrial fibrillation Exaggerated x descent - pericardial Waveform Abnormalities tamponade, constrictive pericarditis Sharp y descent - severe tricuspid regurgitation, constrictive pericarditis Slow y descent - tricuspid stenosis, atrial myxoma Prominent x and y descent - right ventricular infarction