HEMODYNAMIC MONITORING in ICU

HEMODYNAMIC MONITORING in ICU

DR.D.RASIKAPRIYAFIRST YEAR MD PEADIATRICS

PRETEST1. Name some invasive measures and noninvasive ways of hemodynamic monitoring2.Name some advanced hemodynamic monitoring parameters3.What test you do before arterial line insertion4.Name a site contraindicated for arterial line5.Normal mixed venous oxygen saturation6. What is oxygen delivery and oxygen consumption 7.what is passive leg raising test

OBJECTIVESHEMODYNAMICSWhat is it?Why is it important to monitor?Whom to include?How to measure?Its merits and demerits.

HEMODYNAMICS- DEFINITION

the forces which circulate blood through the body. used to describe the intravascular pressure and flow that occurs when the heart muscle contracts and pumps blood throughout the body.

Hemodynamic Monitoringmeasurement of pressure, flow and oxygenation of blood within the cardiovascular system. ORUsing invasive technology to provide quantitative information about vascular capacity, blood volume, pump effectiveness and tissue perfusion. OR measurement and interpretation of biological systems that describes the performance of cardiovascular system

QUESTION???????

HOW MANY TIMES DOES OUR HEART BEATS/DAY?

PURPOSE OF MONITORINGCirculatory shock is an important cause of pediatric morbidity and mortality.Early recognition of inadequate tissue perfusion & oxygenation followed by prompt treatment most important.In pediatric circulatory shock, cardiac output (CO) & BP can be low, normal, or high.Physical examination, poorly reflects CO, preload status, or need for fluid or other hemodynamic interventions. BP & HR often do not reflect blood flow

Potential clinical value of 4 advanced hemodynamic monitoring technologiesCO monitoringVenous oximetryFluid responsivenessLung water

DO2 = SaO2 Hb CO

After load Preload SV HR Contractility

Blood pressure = SVR CO

HEMODYNAMIC PHYSIOLOGY

Physical Examination

Level of consciousness, activity, or agitationState of hydrationPeripheral edemaRespiratory patternPeripheral perfusion/capillary refill timeToe-to-core temperature gapHeart rate and rhythmPulse characteristicsUrine outputHepatomegalyJugular venous pressurePulmonary and cardiac auscultation

METHODSNON INVASIVE INVASIVENIBPECGChest X rayECHO

Blood pressure monitoring-ABPCentral venous pressure monitoringPulmonary artery pressure monitoringMixed venous oxygen monitoringCardiac output

QUESTION???

EACH VENTRICLE EJECTS - ? ml of blood/beat.

NON INVASIVE METHODSBLOOD PRESSURE: INDIRECT ARTERIAL BP MEASUREMENT :palpation method (Riva-Rocci)auscultatory method oscillometric method rheographic method the phase-shift methodultrasonic arterial wall motion detector

CONTD..Flow required across an occlusive cuffMethodsAuscultatoryOscillometricWidth of the inflatable bladder be 40% of the mid-circumference of the limb, length should be twice the width

Auscultatory NIBPPneumatic cuff inflated to occlude arterial blood flowAs cuff is deflated, audible frequencies (Korotkoff sounds) are createdFirst sound = SBPLast sound (or when muffled) = DBP

Auscultatory NIBPErrors in measurement:Long stethoscope tubingPoor hearing in observerCalibration errors of sphygmomanometerDecreased blood flow in the extremitySevere atherosclerosis (unable to occlude)Inappropriate cuff sizeToo rapid deflationaccuracy reduced : low cardiac output, significant hypotension, hypoperfusion, vasoconstriction, dysrhythmias, edema.

Oscillometric NIBPPneumatic cuff inflated to occlude arterial blood flowCuff deflated, arterial pressure pulsations detected and analyzedSBP = rapidly increasing oscillationsMAP = maximal point of oscillationsDBP = rapidly decreasing oscillations Dina map (device for indirect noninvasive mean arterial pressure)

Variations in BP by AgeAgeMean BP (mm Hg)Newborn73/55(30-60)1 year90/556 years95/57(60-100)10 years102/6214 years120/80Adult120/80Elderly (over 70 years)Diastolic pressure may increase

NIBP - ComplicationsToo frequent inflations extremity edemanerve paresthesiascompartment syndromeSkin irritation

ELECTROCARDIOGRAMEvaluation of heart rate and rhythm, ischemia, and conduction defects Trend monitor Sources of errors:Waveform artefact Electrocautery (diathermy) is the main source of electrical interference Muscle activity Movement artefact

INVASIVE MONITORINGINVASIVE BLOOD PRESSURE:Continuous monitoring of systemic arterial blood pressure, Frequent blood sampling, and Withdrawal of blood during exchange transfusions

Arterial Blood Pressure Monitoring Components

Arterial cannula with a heparinized saline column and flushing deviceTransducerAmplifierOscilloscope.

AdvantagesProviding continuous monitoring, Providing access for blood samplingDisplay of the waveform in addition to the BP value True heart rate in the presence of dysrhythmias Allows specific management strategies to be directed by changes in systolic, diastolic, or pulse pressure, rather than mean pressure alone.

ComplicationsBleedingThrombosisHematomaInfectionVascular compromiseNerve damageAccidental injection of air or thrombusDigital necrosisArteriovenous fistulaeCarpal tunnel syndrome

Factors that increase the risk of arterial catheter thrombosis:Larger catheter-to-vessel ratioProlonged cannulationMultiple cannulation attemptsPresence of peripheral vascular diseaseVenous and arterial femoral Catheterization in single extremityYounger ageThrombogenic conditions

Sources of errorInaccurate transducer level. Recordings should be made with the child in the supine position and the transducer at the level of the mid-chest or mid-axillary line. ( 7.5 mm Hg for each 10 cm change in position) ZeroingCareful flushing of the catheter and pressure tubing to remove blood and air bubbles and choosing the shortest, stiffest, and largest catheter.

SVO2 60-75% Stroke volume 50-100 mL Stroke index 25-45 mL/M2 Cardiac output 4-8 L/min Cardiac index 2.5-4.0 L/min/M2 MAP 60-100 mm Hg CVP 2-6 mm Hg PAP systolic 20-30 mm Hg PAP diastolic 5-15 mm Hg PAOP (wedge) 8-12 mm Hg SVR 900-1300 dynes.sec.cm-5

Central Venous Pressure MonitoringIndications:assessment of right heart filling pressure monitoring of large fluid shifts from the intravascular to the extravascular space and vice versa Infusion of vasoactive substances infusion of hyperosmolar fluids and/or irritants

Central Venous Pressure MonitoringSecure IV access in critically ill children who may require large-volume fluid infusions or parenteral nutrition Monitoring cvp-indirect measurement of cardiac preload Provides access for blood sampling for measurement of mixed venous saturation. CVP- 0 6 mmHg

Information Obtained from CVP Waveforms

Loss of A wave and irregular rhythm = suggests atrial fibrillation or flutterCannon A waves = junctional rhythm, complete heart block, ventricular arrhythmias, TS, RVH, PS, Pulm HTN

Complications Central line insertion Indwelling cathetersArterial (carotid, subclavian, femoral) punctureLocal hematomaAir embolismCatheter malposition (to neck tissue, mediastinal, pericardial, or pleural cavities)PneumothoraxHemothoraxBrachial plexus injuryDysrhythmiasInfectionLocal hematomaExtravasationVascular thrombosisEmbolus (clot or air)Intracardiac thrombusSuperior vena cava syndromeChylothoraxLocal nerve damage

PULMONARY ARTERY CATHETERSSeptic shock unresponsive to fluid resuscitation and low-dose vasopressor support, Refractory shock following severe burn injuries,Children with CHD, multiple organ failure, and respiratory failure requiring high mean airway pressures

CAPABILITIES OF PACdetermination of CVP, pulmonary artery pressure (PAP), and pulmonary artery occlusion pressure (PAOP), also referred to as pulmonary capillary wedge pressure (Pw)

PULMONARY ARTERY PRESSURE MONITORINGAssess fluid statusCOtissue oxygenation (Svo2),oxygen delivery (Do2) and consumption (Vo2), pulmonary vascular resistance (PVR) and systemic vascular resistance (SVR)

Complications of PAC PlacementArrhythmias, complete heart blockEndobronchial hemorrhagePulmonary infarctionCatheter knotting and entrapmentValvular damageThrombocytopenia, thrombus formationIncorrect placement, balloon rupture

Cardiac Output MonitoringCO = HR x SV3.5 5 L/min/m2Preload, afterload, HR, contractility determinant of systemic oxygen deliveryshock, multiple organ failure, unexplained hypotension, severe cardiac disease, significant cardiopulmonary interactions.

Measures of adequate o2 supplyMixed venous o2 saturationblood lactateTissue CO2 tonometryNIRS (Near Infrared Spectroscopy)

BLOOD LACTATETissue dysoxia in states of mitochondrial dysfunction associated with sepsis, poisoning, and various inborn errors of metabolism Accelerated anerobic glycolysis Lactate-containing replacement fluids during high-volume hemofiltration Acute hyperventilation can elevate blood lactate levels, perhaps secondary to increased splanchnic release of lactate during hyperventilation

Tissue PCO2 Monitoring Using Tonometry Designed to measure tissue hypoperfusion Involves placement of a CO2-permeable balloon adjacent to a mucosal surface Tissue hypoperfusion- increased intracellular CO2Gastric tonometry: inconsistent resultsSublingual tonometry, suggested during early phases of resuscitation

Near Infrared Spectroscopy Monitoring device for patients with potential hemodynamic instability or deficits in regional (primarily cerebral) perfusion Deoxy Hb absorbs light in the range of 760 nm or lower, whereas both deoxy and oxy Hb absorb light at ~800 nm

TAKE HOME MESSAGE

Multiple different methods of hemodynamic monitoring Keys to successKnow when to use which methodTechnical skills for device placementKnow how to interpret the data

Remember the limitations of the technology

THANK U