Hemodynamics

• Is defined as the study of the forces involved in blood circulation.

• Hemodynamic monitoring is used to assess cardiovascular function in the critically ill or unstable client

• It is indicated when standard vital signs measurements are not adequate to evaluate changes in cardiovascular status.

Purpose

• The main goals of invasive hemodynamic monitoring are to evaluate cardiac function, the condition of the circulatory system, and the clients response to interventions

• Provide additional information which establishes or expands a given diagnosis

• Provides a physiological rationale for a selected therapy

• Allows a rapid determination of the response to therapy or suggest a change in the response

Types

• Intrarterial Blood Pressure Monitoring

• Central Venous Pressure Monitoring

• Pulmonary Artery Pressure Monitoring

• The hemodynamic pressures include heart rate, arterial blood pressure, central blood pressure, pulmonary pressures, and cardiac output

Direct versus Derived Parameters

• Direct hemodynamic parameters are obtained straight from the monitoring device for example the heart rate, and various pressures such as arterial and venous pressures

• Derived hemodynamic pressures are calculated using the direct hemodynamic data; they include such measurements such as cardiac index, mean arterial blood pressure (MAP), and stroke volume (SV)

Hemodynamic Monitoring Systems

• Measure the pressures within the vessel and converts this signal into an electrical waveform that is amplified and displayed

• The electrical signal may be graphically recorded on pressure graph paper and displayed numerically on the monitor

• System components include an invasive catheter threaded into artery or vein connected to a transducer by stiff high-pressure tubing

Hemodynamic Monitoring Systems

• The pressure transducer translates pressure measurements into an electrical signal that is in turn relayed to the monitor

• Additional components include stopcocks and a continuous flush system with heparinized saline and an infusion pressure bag to keep clots from forming in the catheter

Leveling the Transducer

• Is important to ensure accurate readings• The point used as a constant reference

is the level of the right atrium• It is located by intersecting two imaginary

lines: one drawn down the lateral chest wall from the clients 4th intercostal space, the other line is mid chest level (the midaxillary line)

• Once located, this junction is marked with ink or tape and used consistently for pressure readings