Hemodynamic Monitoring Hemodynamic Monitoring and Circulatory Assist Devices • Measurement of pressure, flow, and oxygenation within the cardiovascular system • Includes invasive and noninvasive measurements (Relates to Chapter 66, – Systemic and pulmonary arterial pressures “Nursing Management: Critical Care,” in the textbook)

Hemodynamic Monitoring Hemodynamic Monitoring

• Invasive and noninvasive measurements • Invasive and noninvasive measurements (cont’d) (cont’d) – (CVP) – (SV)/stroke volume index (SVI)

– wedge pressure (PAWP) – O2 saturation of arterial blood (SaO2)

– (CO)/ (CI) – O2 saturation of mixed venous blood (SvO2)

Hemodynamic Monitoring Hemodynamic Monitoring General Principles General Principles • : Volume of blood within at • Contractility: Strength of ventricular end of contraction • Afterload: Forces opposing ventricular • PAWP: Measurement of pulmonary capillary ejection pressure; reflects left ventricular end‐diastolic – Systemic arterial pressure pressure under normal conditions – Resistance offered by – Mass and density of blood to be moved

1 Hemodynamic Monitoring Principles of Invasive Pressure General Principles Monitoring • CVP: Right ventricular preload or right • Equipment must be referenced and zero ventricular end‐diastolic pressure under balance to environment and dynamic normal conditions, measured in right atrium response characteristics optimized or in vena cava close to • Referencing: Positioning transducer so zero reference point is at level of atria of heart or phlebostatic axis

Identification of Principles of Invasive Pressure Phlebostatic Axis Monitoring • Zeroing: Confirms that when pressure within system is zero, monitor reads zero – During initial setup of arterial line – Immediately after insertion of arterial line

Fig. 66-4

Principles of Invasive Pressure Types of Invasive Pressure Monitoring Monitoring • Zeroing (cont’d) • Continuous arterial pressure monitoring – When transducer has been disconnected from – Acute hypertension/hypotension pressure cable or pressure cable has been – Respiratory failure disconnected from monitor – Shock – When accuracy of values is questioned – Neurologic shock

2 Components of an Arterial Pressure Types of Invasive Pressure Monitoring Monitoring System • Continuous arterial pressure monitoring (cont’d) – Coronary interventional procedures – Continuous infusion of vasoactive drugs – Frequent ABG sampling

Fig. 66-3

Arterial Pressure Monitoring Arterial Pressure Tracing

• High‐ and low‐pressure alarms based on patient’s status • Measure at end of expiration • Risks – Hemorrhage, infection, thrombus formation, neurovascular impairment, loss of limb

Fig. 66-6

Arterial Pressure Monitoring Pulmonary Artery Pressure Monitoring

• Continuous flush irrigation system • Guides management of patients with – Delivers 3 to 6 ml of heparinized saline per hour complicated cardiac, pulmonary, and • Maintains line patency intravascular volume problems • Limits thrombus formation – PA diastolic (PAD) pressure and PAWP: Indicators – Assess neurovascular status distal to arterial of cardiac function and fluid volume status insertion site hourly – Monitoring PA pressures allows for therapeutic manipulation of preload

3 Insertion of Pulmonary Artery Pulmonary Artery Catheter Catheter

Fig. 66-7 Fig. 66-8

Pulmonary Artery Pressure PA Waveforms during Insertion Monitoring • When measurements are obtained – PA: At end expiration – PAWP: By inflating balloon with air until PA waveform changes to a PAWP waveform • Balloon should be inflated slowly and for no more than four respiratory cycles or 8 to 15 seconds

Fig. 66-9

Central Venous Pressure Measuring Cardiac Output Monitoring • Measurement of right ventricular preload • Intermittent bolus thermodilution method – Obtained from • Continuous cardiac output method • PA catheter using one of the proximal lumens • Central venous catheter placed in internal jugular or subclavian vein

4 Measuring Cardiac Output Complications with PA Catheters

• Infection and sepsis – Asepsis for insertion and maintenance of catheter and tubing mandatory – Change flush bag, pressure tubing, transducer, and stopcock every 96 hours • Air embolus (e.g., disconnection)

Fig. 66-12

Complications with PA Catheters Pulmonary Artery Waveforms

• Ventricular dysrhythmias – During PA catheter insertion or removal – If tip migrates back from PA to right ventricle • PA catheter cannot be wedged – May need repositioning

Fig. 66-10

Preventing PA Rupture and Nursing Management Pulmonary Infarction Hemodynamic Monitoring • Never inflate balloon beyond balloon’s • Baseline data obtained capacity – General appearance – Usually 1 to 1.5 ml of air – Level of consciousness • Check PA pressure waveforms often for signs – Skin color/temperature of catheter occlusion, dislocation, or – Vital signs spontaneous wedging – Peripheral – Urine output

5 Nursing Management Nursing Management Hemodynamic Monitoring Hemodynamic Monitoring • Baseline data correlated with data obtained • Monitor trends and evaluate whole clinical from biotechnology picture (e.g., ECG; arterial, CVP, PA, and PAWP • Goals pressures; SvO2/ScvO2) – Recognize early clues • Single hemodynamic values are rarely – Intervene before problems develop or escalate significant

Circulatory Assist Devices (CADs) Intraaortic Balloon Pump (IABP)

• Decrease cardiac work and improve organ • Provides temporary circulatory assistance when drug therapy fails – ↓ Afterload • Provide interim support when – Augments aortic diastolic pressure – Left, right, or both ventricles require support • Outcomes while recovering from injury (MI) – Improved coronary blood flow – Heart requires surgical repair and patient must – be stabilized Improved perfusion of vital organs (e.g., ruptured septum) – Heart has failed and patient needs cardiac transplantation

IABP Machine IABP

Fig. 66-13 Fig. 66-14

6 Ventricular Assist Devices (VADs) Schematic Diagram of Left VAD

• Provides longer‐term support for failing heart • Allows more mobility than IABP • Inserted into path of flowing blood to augment or replace action of ventricle

Fig. 66-16

Nursing Management Ventricular Assist Devices (VADs) Circulatory Assist Devices • Indications for VAD therapy – Observe patient for: Bleeding, cardiac tamponade, – Extension of cardiopulmonary bypass ventricular failure, infection, dysrhythmias, renal failure, hemolysis, and thromboembolism • Failure to wean • Postcardiotomy – Patient may be mobile and will require an activity – Bridge to recovery or cardiac transplantation plan

SIRS

SIRS and MODS • Systemic inflammatory response syndrome (SIRS) is a systemic inflammatory response to a variety of insults • Generalized inflammation in organs remote (Relates to Chapter 67, from the initial insult “Nursing Management: Shock, Systemic Inflammatory Response Syndrome, and Multiple Organ Dysfunction Syndrome,” in the textbook)

7 SIRS SIRS

• Triggers • Triggers – Microbial invasion: Bacteria, viruses, fungi – Mechanical tissue trauma: burns, crush injuries, – Endotoxin release: Gram‐negative bacteria surgical procedures – Global perfusion deficits: Post–cardiac – Abscess formation: intra‐abdominal, extremities resuscitation, shock states – Ischemic or necrotic tissue: pancreatitis, vascular – Regional perfusion deficits: Distal perfusion disease, myocardial infarction deficits

MODS MODS

• Multiple organ dysfunction syndrome – SIRS and MODS represent the ends of a (MODS) is the failure of two or more organ continuum systems – Transition from SIRS to MODS does not occur – Homeostasis cannot be maintained without in a clear‐cut manner intervention – Results from SIRS

Relationship of Shock, SIRS, and MODS SIRS and MODS

• Consequences of inflammatory response – Release of mediators – Direct damage to the endothelium – Hypermetabolism – leading to decreased SVR – Increase in vascular permeability – Activation of coagulation cascade

Fig. 67-1

8 SIRS and MODS SIRS and MODS Pathophysiology Pathophysiology

• Organ and metabolic dysfunction • Respiratory system – Hypotension – Alveolar edema – Decrease in surfactant – Decreased perfusion – Increase in shunt – Formation of microemboli – V/Q mismatch – Redistribution or shunting of blood – End result: ARDS

SIRS and MODS SIRS and MODS Pathophysiology Pathophysiology

• Cardiovascular system • Neurologic system – Myocardial depression and massive vasodilation – Mental status changes due to hypoxemia, inflammatory mediators, or impaired perfusion – Often early sign of MODS

SIRS and MODS SIRS and MODS Pathophysiology Pathophysiology

• Renal system • GI system – Acute renal failure – Motility decreased: Abdominal distention and paralytic ileus • Hypoperfusion – Decreased perfusion: Risk for ulceration and GI • Release of mediators bleeding • Activation of renin–– aldosterone system – Potential for bacterial translocation • Nephrotoxic drugs, especially antibiotics

9 SIRS and MODS SIRS and MODS Pathophysiology Pathophysiology

• Hypermetabolic state • Hematologic system – Hyperglycemia–hypoglycemia – DIC – Insulin resistance – Catabolic state • Electrolyte imbalances – Liver dysfunction • Metabolic acidosis – Lactic acidosis

SIRS and MODS SIRS and MODS Collaborative Care Collaborative Care

• Prognosis for MODS is poor • Prevention and treatment of infection • Goal: Prevent the progression of SIRS to – Aggressive infection control strategies to MODS decrease risk for nosocomial infections • Vigilant assessment and ongoing monitoring – Once an infection is suspected, institute to detect early signs of deterioration or interventions to control the source organ dysfunction is critical

SIRS and MODS SIRS and MODS Collaborative Care Collaborative Care

• Maintenance of tissue oxygenation • Maintenance of tissue oxygenation

– Decrease O2 demand – Optimize O2 delivery • Sedation • Maintain normal hemoglobin level • Maintain normal PaO • Mechanical ventilation 2 – Individualize tidal volumes with • Paralysis PEEP • Analgesia

10 SIRS and MODS SIRS and MODS Collaborative Care Collaborative Care

• Maintenance of tissue oxygenation • Nutritional and metabolic needs – Enhance CO – Goal of nutritional support: Preserve organ function – Increase preload or myocardial – Total energy expenditure is often increased 1.5 contractility to 2.0 times – Reduce afterload

SIRS and MODS SIRS and MODS Collaborative Care Collaborative Care

• Nutritional and metabolic needs • Support of failing organs

– Use of the enteral route is preferred to – ARDS: Aggressive O2 therapy and mechanical ventilation parenteral nutrition – DIC: Appropriate blood products – Monitor plasma transferrin and prealbumin levels to assess hepatic protein synthesis – Renal failure: Continuous renal replacement therapy or dialysis

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