HEMODYNAMIC MONITORING

By

Yasmeen Rahim

OBJECTIVES By the end of this session, learners will be

able to: Define what is hemodynamic monitoring. List down the importance of hemodynamic

monitoring in hospital. Discuss about pressure monitoring system. Identify troubleshooting in the pressure

monitoring system.

CONT. Explain in detail about arterial pressure

monitoring, central venous pressure monitoring and pulmonary artery pressure monitoring.

Evaluate oxygen delivery and demand.

HEMODYNAMIC MONOTORING

It is the study of interrelationship of blood pressure, blood flow, vascular volumes, heart rate, ventricular function and the physical properties of blood at bedside

Is an integral part of critical care nursing

Cont.. CCN should have knowledge of how to

obtain accurate data, analyze waveforms and interpret and integrate the data.

The information provided by invasive catheters can give us accurate and timely information to clinicians so that appropriate interventions can be taken.

IMPORTANCE OF HDM

Early detection, identification, and treatment of life-threatening conditions such as heart failure and cardiac temponade.

Evaluate the patient’s immediate response to treatment such as drugs and mechanical support.

Evaluate the effectiveness of cardiovascular function such as cardiac output and index.

PURPOSE OF HDM: The purpose of HDM is to:

Early detection, identification, and treatment of life-threatening conditions

Aid in the diagnosis of various cardiovascular disorders

Guide therapies to optimize cardiac functions Minimize cardiovascular dysfunctions Evaluate the patient’s immediate response to

treatment modalities

INDICATION OF HDM It is essential in conditions when cardiac output is

insufficient to deliver oxygen to the cells (altered preload, afterload and contractility).

Any deficit or loss of cardiac function: such as AMI, CHF, Cardiomyopathy.

All types of shock; cardiogenic, septic, neurogenic or anaphylactic.

Dehydration, hemorrhage, G.I. bleed, severe burn, ARDS or any major surgery.

Severe sepsis or multiple organ failure. It aids in assessing body oxygen supply and demand.

HDM PARAMETERS: Cardiac output.

Heart rate Rhythm

Cardiac index. Stroke volume.

Preload Afterload Contractility

PRESSURE MONITORING SYSTEM

Catheter (hollow tube). Central venous catheter for CVP Arterial catheter for Arterial pressure monitoring Pulmonary catheter / SWAN Ganz for PAP monitoring.

Pressure tubing. Flush solution (N/S or D5W, heparinized) IV tubing with drip chamber Pressure bag (pressure of 300 mmHg) and stopcock

Pressure transducer. Pressure amplifier. Cardiac monitor

SQUARE WAVE TEST: Square wave test is performed to quickly assess

the response of the system. Flush device is released rapidly which will

increase fluid flow through the system. Record the square wave formed on the monitor.

LEVELING & ZEROING: A fundamental step in obtaining accurate

hemodynamic values is to zero the transducer amplifier system.

This step is performed at least once before obtaining the first hemodynamic reading after catheter insertion.

The pressure monitoring system is leveled to an external landmark and then zeroed to atmospheric pressure.

Zeroing is done to eliminate the effect of atmospheric and hydrostatic pressure.

Cont.. The phlebostatic axis is used as the reference

point for leveling and zeroing. The site of the phlebostatic axis is at the

intersection of the fourth intercostal space and mid axillary line (approx level of right atrium and pulmonary artery.

Leveling (referencing) and zeroing ensures that hemodynamic values obtained with the catheter are accurate.

STEPS FOR ZEROING AND LEVELING: Position patient on their back Patient may be positioned with the head of the bed elevated

between 0-60° Flush the system Level transducer to phlebostatic axis (may mark this with an x

on patient) Turn stop-cock on transducer so that it is off to the patient. Remove cap Press zero on the module Ensure that zero appears on screen replace cap and turn

stop-cock so that it is open to monitoring and patient.

ARTERIAL PRESSURE MONITORING:

Arterial blood pressure is a basic hemodynamic index often utilized to guide therapeutic interventions

Continuous monitoring of blood pressure is indicated for patients with hemodynamic instability that requires inotropic or vasopressor medication

Cont. An arterial line is a cannula usually

positioned in a peripheral artery such as Radial artery (most commonly used site) Brachial artery (rarely used) Dorsalis pedis artery (rarely used) Femoral artery (second option other than radial

artery, more chances of getting contaminated)

Cont.. An arterial line allows for consistent and

continuous monitoring of blood pressure to facilitate the reliable titration of supportive medications

In addition, arterial lines allow for reliable access to the arterial circulation for the measurement of arterial oxygenation and for frequent blood sampling

ARTERIAL LINE INSERTION: http://content.nejm.org/cgi/video/354/15/e1

3/

ARTERIAL PRESSURE Arterial pressure waveform has three parts:

Rapid upstroke wave (systolic pressure) Dicrotic notch Diastolic pressure waveform

Normal systolic BP is 90 – 140 mm Hg. Normal diastolic BP is 60 – 90 mm Hg. Dicrotic notch is small downward deflection

following the closure of semilunar valve, indicate the end of systole and beginning of diastole.

MEAN ARTERIAL PRESSURE:

Mean arterial pressure (MAP) is used to evaluate perfusion of vital body organs.

Normal MAP is 70 to 105 mm Hg. MAP can be calculated by:

Systolic BP + (Diastolic *2) / 3

EJECTION FRACTION Ejection Fraction (EF) is the fraction of

blood ejected by the ventricle relative to its end-diastolic volume. 

EF is calculated from:

EF = (SV / EDV) * 100 For example if SV is 75 and EDV is 120

then EF would be 63%.

POTENTIAL COMPLICATIONS HAEMORRHAGE:

PREVENTION: Keep limb visible at all times Ensure alarm is on so that any accidental disconnection

can be dealt quickly Ensure that arm is immobile with arm board Ensure all connections are tightSOLUTION Apply pressure to limb Assess leak If hemorrhage persists notify medical officer

CONT.. INFECTION PREVENTION

Assess area regularly for redness or swelling Avoid interrupting circuit as much as possible Use gloves when touching arterial line

SOLUTION Remove arterial Line Ensure proper hand washing when handling

arterial line or transducer

CONT.. BLOCKAGE, CLOTTING & AIR EMBOLI PREVENTION

Keep pressure bag inflated to 300 mmHg ensure 3-5ml auto flush is continuous. Attempt to aspirate blood Use fast flush device to clear line to prevent clot

formation

SOLUTION Attempt to aspirate blood to remove clot Ensure all connections are secure

CONT.. INTERUPTION TO PERIPHERAL

CIRCULATION

PREVENTION Regularly check distal pulses and capillary refill.

SOLUTION Notify MO and consider removing arterial line

NURSING CONSIDERATIONS Nursing care mainly directed to preventing

complications Ensure that the insertion site is visible at all

times for early detection of disconnection All connections must be secured Ensure that the cannula site is covered with

an appropriate dressing to maintain asepsis

Cont. Never inject anything into an arterial cannula

or arterial line Ensure that the flush bag has adequate fluid. Use only heparinized 0.9% sodium chloride Ensure that the pressure in the pressure bag

is maintained at 300mmHg. Always set and keep the alarms on.

Cont. Do not allow the flush bag to empty

To maintain patency of arterial cannula. To prevent air embolism To maintain accuracy of blood pressure reading To maintain accuracy of fluid balance chart To prevent backflow of blood

Cont. Monitor color & temperature of limb distal to

arterial line & compare to other limb To confirm that circulation to the limb is

adequate. To ensure the early detection of impaired

circulation

Cont. Monitor and display the arterial waveform at

all times To detect cannula disconnection.

Level and zero transducer once per shift To ensure accuracy in measuring blood pressure

Maintain the transducer level with the patient’s phlebostatic axis (fourth intercostal space midaxillary line)

Cont. On removal of arterial cannula maintain

pressure over puncture site for at least 5 minutes until bleeding has stopped To prevent bleeding and haematoma formation

Send cannula tip to microbiology Only if suspected infection To detect infection

CENTRAL VENOUS PRESSURE Is the pressure within the superior vena cava or

the right atrium It serve as a guide to fluid balance in critically ill

patients It give estimation of the circulating blood volume It also assist in monitoring of rt ventricular function Route for delivery of medications

Cont. CVP is a helpful tool in the assessment of

cardiac function, circulating blood volume, and patient’s response to treatment

CVP should not be interpreted solely but in conjunction with other systemic measurements, as isolated CVP measurements can be misleading

Normal CVP is less than 8 mm Hg CVP is raised in mechanical ventilation.

CVP INSERTION: http://content.nejm.org/cgi/video/356/21/e21/

METHODS OF CVP MONITORING There are two methods of CVP monitoring

manometer system: enables intermittent readings and is less accurate than the transducer system

transducer system: enables continuous readings which are displayed on a monitor.

MONITORING WITH TRANSDUCERS

Transducers enable the pressure readings from invasive monitoring to be displayed on a monitor

To maintain patency of the cannula a bag of normal saline or heparinized saline should be connected to the transducer tubing and kept under continuous pressure of 300mmHg. (autoflush 3ml/hr)

PROCEDURE FOR CVP MEASUREMENT USING A TRANSDUCER

Explain the procedure to the patient Ensure that central line is patent Position the patient supine (if possible) and

align the transducer with the phlebostatic axis Zero the monitor Observe the CVP tracing Document the reading and report any changes

or abnormalities

COMPLICATIONS Infection Arterial puncture Hematoma Pneumothorax Hemothorax Arrhythmias Thrombosis Air embolism

MANAGEMENT OF A PATIENT WITH A CVP LINE Monitor patient for signs of complications Label CVP lines with drugs/fluids etc. being infused in

order to minimise the risk of accidental bolus injection Ensure all connections are secure to prevent infection

and introduction of air emboli Observe the insertion site frequently for signs of

infection. CVP lines should be removed when clinically

indicated

REMOVAL OF CENTRAL LINES This is an aseptic procedure The patient should be supine with head tilted down Ensure no drugs are attached and running via the

central line Remove dressing Cut the stitches Slowly remove the catheter If there is resistance then call for assistance Apply digital pressure with gauze until bleeding stops Dress with gauze and do clear dressing eg tegaderm

PA PRESSURE MONITORING Pulmonary artery pressure monitoring is

measuring the pressure in the pulmonary artery leading to the lungs

It also allows for indirect measurement of left heart pressures since the pulmonary veins have no valves in them and collects the information needed to calculate cardiac output and resistance

Cont. The PA catheter assesses right ventricular

function, pulmonary vascular status, indirectly left ventricular function and all 3 components of stroke volume

PAC aids in diagnosis of cardiovascular and cardiopulmonary dysfunction, therapy needed, and evaluate effectiveness of interventions.

PULMONARY ARTERY CATHETER

A Pulmonary artery catheter is a multi lumen catheter inserted into pulmonary artery.

Each lumen or port has specific functions. Veins used for PA catheter insertion include

the internal jugular, subclavian, femoral and very less commonly brachial.

Components of Swan-Ganz [con’t] Proximal port – [Blue] used to measure

central venous pressure/RAP and injectate port for measurement of cardiac output

Distal port – [Yellow] used to measure pulmonary artery pressure and for withdrawal of mixed venous saturation. Medication administration from this port is not recommended.

Cont.. Balloon port – [Red] used to determine

pulmonary wedge pressure;1.5 ml air is injected via special syringe already attached with the catheter.

Thermister port- [White] it measures patients temperature in the pulmonary artery and reflect the temperature change when fluid is injected for cardiac output.

PA CATHETER INSERTION http://www.edwards.com/products/pacathet

ers/catheterizationtechniques.htm?ccombo=1

http://www.edwards.com/Products/PACatheters/HDMTroubleshooting.htm

INDICATIONS: To assess volume status and myocardial function. To assist in making a differential diagnosis To guide the management of the patient with heart/lung

disease/shock of all types To monitor hemodynamic pressures during fluid resuscitation Inotropic/vasoconstrictor/vasodilator drug infusion therapy To assess complications of MI and heart failure To monitor hemodyanamics with complicated surgical

procedures Sepsis and multi system organ failure Complex surgery, complicated myocardial infarction

CONTRAINDICATION: Severe coagulopathy. Patient receiving thrombolytics (e.g-TPA). Prosthetic right heart valve - catheter may cause the valve to

malfunction. Endocardial pacemaker - catheter may dislodge or knot around

the electrode. Severe pulmonary hypertension - increased risk of PA rupture. Severe vascular disease - catheter may puncture an abnormal

vessel. Significant immunodeficiency. If there are no skilled physicians/staff. If the patient's disease or injury can't be modified or corrected by

therapy.

COMPLICATIONS DURING INSERTION:

Pneumothorax Venous air embolism Dysrhythmias Dislodgement of the catheter guide wire Excessive bleeding

COMPLICATIONS AFTER INSERTION:

Dysrhythmias Infection Catheter dislodgement Thrombophlebitis Pulmonary artery rupture Tension Pnuemothorax

Cont.. Catheter wedges permanently—considered an

emergency, notify MD immediately, can occur when balloon is left inflated or catheter migrates too far into pulmonary artery (flat PA waveform)…can cause pulmonary infarct after only a few minutes!

Ventricular irritation – occurs when catheter migrates back into RV or is looped through the ventricle, notify MD immediately…can cause VT

• Check coagulation labs (pt, ptt, INR, platelets)• Transfuse if Platelets < than 70 and INR > 1.5• Ensure Packed Red Blood Cells in cooler at bedside (Remember two RN check for PRBCs. Instructions for blood in cooler, taped to cooler)• Ensure good vascular access• Evaluate need for sedation. (if too active ↑ BP may → bleeding)

NURSING CARE BEFORE REMOVAL OF PAC

• Keep PRBCs for a minimum of 1 hour• Continuous hemodynamic monitoring for minimum 1hour• Assess for signs of tamponade-dampening arterial wave form, narrowing pulse pressure and bleeding- blood in chest tubes, decrease blood pressure, pallor altered LOC)• Document vital signs every 15 minutes • Check HCT if bleeding suspected• Ensure patency of chest tubes• Do not transfer patient for at least 2 hours

NURSING CARE AFTER REMOVAL OF PAC

TROUBLESHOOTING: Remove multiple stopcocks, multiple injection

ports, and long lengths of tubing whenever possible

The optimal length of pressure tubing is 4 feet Overly compliant tubing leads to over damping Avoid large diameter tubing Remove all air bubbles from the system Ensure that all connections are tight and

periodically flush all tubing and stopcocks to remove air bubbles

Cont… Whenever you are evaluating a patient’s changing

hemodyanamics check all transducers, stopcocks, tubing, and injection ports for air

Gently tap the tubing and stopcocks as the continuous flush valve is opened to dislodge any bubbles.

This will usually clear the system and restore measurement accuracy

Flushing a few small bubbles through the catheter is OK; if more air is present, aspirate it from the tubing

Cont… Changes in bed positioning generally

require re zeroing the pressure transducer If the transducer is below the phlebostatic

axis, the resulting arterial pressure will be erroneously high If the transducer is above the phlebostatic

axis, the resulting arterial pressure will be erroneously low

Documentation

Document PAS, PAD, and PCWP on nursing flowsheet under Hemodynamic Parameters

PCWP will rarely be > PAD (if so, means blood is flowing backwards) If PCWP = PAD, look for tamponade

Under circumstances where the catheter will not wedge (or should not be), do not document any values in the PCWP column on the flowsheet.