Chapter 2 Hemodynamic monitoring critical theory 2024 2025.pdf

Chapter 2 Hemodynamic monitoringEffusic output Dr. Rana Al Awamleh Hanadi Yousef 2024 Dr. Rana Al Awamleh, Hanadi Yousef 1 Hemodynamic monitoring It is continuous monitoring of the pressures being exert...

Chapter 2 Hemodynamic monitoringEffusic output Dr. Rana Al Awamleh Hanadi Yousef 2024 Dr. Rana Al Awamleh, Hanadi Yousef 1 Hemodynamic monitoring It is continuous monitoring of the pressures being exerted on or within the veins, arteries, and heart. Hemodynamic monitoring is a diagnostic tool, not a treatment The information gained from hemodynamic monitoring is used to evaluate cardiovascular performance, which includes: EI information about the cardiac output (CO), tissue perfusion, blood volume, tissue oxygenation, and vascular tone. Accurately determined hemodynamic values are used to guide fluid and occasionally blood administration and cardiovascular drug–based and device- based therapies provided to patients who are critically ill Dr. Rana Al Awamleh, Hanadi Yousef 2 Hemodynamic monitoring : The three overarching assessment parameters provided by hemodynamic monitoring are calculation of preload (end-diastolic volume and pressure in both see ventricles before contraction) afterload (pressure created by blood volume and arterial tone, which the heart must overcome to open 50 the aortic and pulmonic heart valves). O contractility (ability of the heart muscle to pump/contract effectively). Dr. Rana Al Awamleh, Hanadi Yousef 3 Hemodynamic monitoring Preload, afterload, contractility, and HR ultimately determine stroke volume (SV), CO, and BP. Changes in any of the four determinants of CO o (preload, afterload, contractility, or HR) may produce significant adverse effects on BP with resulting adverse changes in cellular function and energy production as a result of altered tissue perfusion. 0 Hemodynamic monitoring helps to assess these parameters in the patient who is critically ill Dr. Rana Al Awamleh, Hanadi Yousef 4  Pulmonary artery catheter (PAC) A PA catheter is a flow-directed, balloon-tipped catheter, in the Swan-Ganz. PA = pulmonary artery catheter. What does a PA catheter measure? ~ A PA catheter measures ooo pressures in the right atrium, pulmonary artery, and left ventricle. Dr. Rana Al Awamleh, Hanadi Yousef 5 Determinants of cardiac output and blood pressure He o The most powerful determinant of CO is tissue oxygen (O2) demand. As metabolism and O2 consumption increase or decrease, the heart responds, and CO increases or decreases in direct response to increased or decreased need The right and left sides of the heart are connected by the pulmonary arteries and veins. Many specialized types of central vessel and arterial catheters are available to measure the pressures within the cardiopulmonary circulation and provide a means to calculate CO All PA catheters provide information about the right side and left side of the heart, as well as systemic circulation. Options for measurements vary with each uniquely configured catheter. Once the hemodynamic data are evaluated, strategies may be implemented to manipulate preload, afterload, contractility, and HR. Dr. Rana Al Awamleh, Hanadi Yousef 6 Preload Preload is determined by the compliance (ability to stretch) of the ventricles during diastole as the blood volume fills the ventricles. As the blood volume increases, the heart must “stretch” with each heartbeat to accommodate it. As the blood volume decreases, the heart stretches much less but must still generate the force needed to propel the blood volume forward during systole. a a Factors that affect ventricular blood volume include venous return, circulating blood volume, condition of the heart valves, and atrial contractility. Ventricular compliance is affected by stiffness and thickness of the cardiac muscle Any stressor that influences one of these factors will result in a change in preload, with a concequnce change in CO Dr. Rana Al Awamleh, Hanadi Yousef 7 Preload Heart disease affects preload. Patients with biventricular heart failure and/or “stiff ventricles” are not able to handle increased intravascular volume. Their preload is always high because the heart cannot stretch normally to accommodate more volume. If preload begins to increase in a patient with heart disease, appropriate medications, including diuretics, may be given to help decrease CVP Vasodilating drugs with strong venodilating properties may also be used to decrease venous return so that a heart with limited ability to stretch can accommodate and pump the lesser blood volume. 22,8 Decreased preload is seen with hypovolemia and certain types of shock where vasomotor tone is affected causing vasodilation. Decreased preload can lead to a decrease in CO related to the decrease in SV Dr. Rana Al Awamleh, Hanadi Yousef 8 Afterload It is the pressure or force that must be generated within the right and left ventricles/ventricular myocardium during systole to overcome the vascular resistance to ejection. The pressures created by the blood volume and vascular tone within the pulmonary, aortic, and systemic circulation create resistance against the aortic and pulmonic valves, which can impede ventricular ejection. Other resistant forces include increased blood viscosity, reduced distensibility of the vascular system (created by atherosclerosis or “hardening of the arteries”), and diseased heart valves. aYessianee If blood volume starts to be retained in the ventricles, rather than being normally ejected, lead to increases in PA pressure. When these changes are observed, measures such as administration of diuretics or vasodilating drugs with strong arterial dilating properties may be initiated to decrease afterload and help improve ventricular ejection. Medications used for management of hypertension are administered to reduce afterload any antihypertesion Dr. Rana Al Awamleh, Hanadi Yousef 9 Afterload The higher the afterload, the greater the myocardial wall tension/pressure must be to open so the aortic and/or pulmonic valves, and the greater is the work of the heart to overcome resistance to flow. This explains why hypertension is called “the silent killer,” because the constantly increased afterload strains the heart. MCW 0 Increased cardiac work requires increased myocardial blood flow to deliver additional O2. Dr. Rana Al Awamleh, Hanadi Yousef 10 Contractility factors positively influence contractility include: sympathetic stimulation, find.it qq.fi calcium, and positive inotropic agents, such as digitalis, dobutamine, and beta-adrenergic drugs. contract Factors can decrease contractility include: acidemia, hypoxia, myocardial ischemia, myocardial infarct, I cardiomyopathies, beta-blocker drugs, and antidysrhythmic drugs taobao.com Dr. Rana Al Awamleh, Hanadi Yousef 11 Heart rate Slight increases in HR with a constant SV result in increased CO. Very rapid HRs are associated with a reduction in CO as the duration of diastole is shortened, resulting in decreased coronary perfusion and reduced ventricular filling time Patients who are critically ill often manifest sinus tachycardia to maintain a CO that meets the demand for O2 and nutrients at the cellular level. Dr. Rana Al Awamleh, Hanadi Yousef 12 Hemodynamic assessment The goal of hemodynamic monitoring is to obtain accurate EEE measurements and to observe trends in values that are used in combination with physical assessment findings to provide appropriate, effective therapies to D maintain adequate BP, CO, and tissue perfusion. Dr. Rana Al Awamleh, Hanadi Yousef 13  Hemodynamic normal values Parameter Normal values Arterial blood pressure (BP) systolic (SBP)/diastolic S 90 to 130/ D 50 to 80 mm Hg Mean arterial pressure (MAP) 70 to 100 mm Hg Central venous pressure (CVP)* 2 to 6 mm Hg Right atrial pressure (RAP)* Left atrial pressure (LAP) I 2 to 6 mm Hg 8 to 12 mm Hg 6 to 12 mm Hg wedge (pulmonary capillary wedge pressure [PCWP] or pulmonary wedge pressure [PWP]) Dr. Rana Al Awamleh, Hanadi Yousef 14  Systemic arterial pressure or blood pressure may be measured indirectly and/or directly Indirect measurement: A “spot check” or “snapshot” of the BP in a moment of time, performed with a manually inflated BP cuff and manometer. to Dev ar f D Direct measurement: Continuous monitoring of BP that requires insertion of a hollow, semirigid catheter into an artery to create an arterial line (A-line). When an arterial line is used to I measure BP, it is labeled ABP to distinguish this from a noninvasive measurement. O me BP is a dynamic or ever-changing event and the continuous monitoring of ABP reflects the beat- to-beat changes that occur. Cardiovascular dynamics are assessed through a review of pressure waveforms and analysis of trends in arterial pressure readings. Dr. Rana Al Awamleh, Hanadi Yousef 15  Arterial lines Are used to obtain arterial blood samples for lab This will be discussed in work, including blood gas lab sessions determinations, without repeated arterial punctures. Dr. Rana Al Awamleh, Hanadi Yousef 16 Arterial oxygen saturation Foggie The percentage of oxyhemoglobin (Hgb bound with O2) compared fI with the total amount of Hgb can be measured directly using blood samples from the arterial line or approximated indirectly by photoelectric technology using an external pulse oximetry probe placed on the patient’s finger, ear, or forehead ABG This will be discussed in lab sessions Dr. Rana Al Awamleh, Hanadi Yousef 17  2 6 wants Central venous pressure or right atrial pressure To e L is CVP can be monitored continuously or “spot checked” using a central line. CVP and RAProar sina.im may be used interchangeably to assess intravascular fluid volume, efficacy of venous return to the right side of the heart, and RVEDP or preload. Specialized CV catheters allow continuous venous oximetry (ScVO2) monitoring that provides information on oxygen use. This will be discussed in the lab sessions Dr. Rana Al Awamleh, Hanadi Yousef 18  Pulmonary artery pressures PAPs are measured continuously using a flow-directed, multilumen catheter placed in the PA More sophisticated catheters provide information about O2 delivery and O2 consumption and may provide continuous cardiac output (CCO) measurements. Basic PA catheters provide measurement of RAP, PAP, and CO The hemodynamic measurements paired with the data gathered about oxygen delivery and oxygen use give the clinician information about tissue perfusion These measurements also provide information that helps in calculating preload, afterload, and contractility. Waveform analysis helps to identify any pathology or abnormality of the heart valves and other cardiac disorders. Dr. Rana Al Awamleh, Hanadi Yousef 19  Cardiac output/ (CO) CO can be calculated using several methods One of these methods is: Continuous cardiac output measurement: Performed using a specialized PA catheter using thermal technology that allows the user to obtain readings that are averaged over 3-minute periods and updated every 30 to 60 seconds. Dr. Rana Al Awamleh, Hanadi Yousef 20 Promoting accuracy of hemodynamic values: Setting up equipment 2 no Ensuring proper setup and maintenance of the pressure monitoring system will prevent most inaccuracies. Normal waveform configurations must be understood for all readings so that abnormal waveforms can be readily identified. Abnormal waveforms can sometimes reflect a problem with the system setup or maintenance Dr. Rana Al Awamleh, Hanadi Yousef 21 Mechanical ventilation Dr. Rana Al Awamleh, Hanadi Yousef 22 Mechanical ventilation Provides assistance with movement of gases in and out of the lungs to facilitate blood-alveolar o clearance of CO2 and uptake of O2 into the blood. o For ventilation to be effective: The nervous system must be intact, the diaphragm and respiratory muscle groups must be e contract, the rib cage must be intact, and intrapleural or intraalveolar pressures should be normal When patients are too weak to generate adequate force (negative pressure), too weak to maintain their airway, too sick or sedated to stimulate and contract the diaphragm, or when the conducting airways or the alveolar units are constricted, collapsed, or congested ventilator support may be unavoidable. Dr. Rana Al Awamleh, Hanadi Yousef 23 CONDITIONS THAT MAY REQUIRE VENTILATOR SUPPORT Acute obstructive disease: acute severe asthma; airway mucosal edema intracranial hemorrhage Atelectasis: acute respiratory distress syndrome; pneumonia Burns and smoke inhalation: inhalation injury, surface burns Cancer: malnutrition Cardiopulmonary problems: congestive heart failure; pulmonary hemorrhage Chest trauma: blunt injury; flail chest; penetrating injuries Chronic obstructive pulmonary disease: emphysema, chronic bronchitis, asthma; cystic fibrosis; Fatigue/atrophy Head/spinal cord injury Postoperative conditions: cardiac and thoracic surgeries Pharmacologic agents/drug overdose: muscle relaxants; Dr. Rana Al Awamleh, Hanadi Yousef was 24  Review of basic ventilation min terms RR 12min Respiratory rate (RR or f [frequency of breathing]) Charted as breaths per minute. The frequency of breaths enabled by the patient and/or delivered by the ventilator may range from 10 to 30 bpm depending on ventilation strategies, except during weaning, E when the frequency of breaths may be less than 10 to augment, rather than fully support, breathing Dr. Rana Al Awamleh, Hanadi Yousef 25  Review of basic ventilation terms Tidal volume (VT): Volume (amount) of gas delivered with each preset breath. 8mLkg In patients who are mechanically ventilated, VT is usually set at 8 mL/kg. VT decreases to 6 mL/kg if the patient has a noncompliant lung condition Minute ventilation (Ve VTE or M ) The amount of volume exhaled per minute (VE or VTE). Measured as: Respirations × VTE (MV). Normal is 8 to 10 L/min. Dr. Rana Al Awamleh, Hanadi Yousef 26 Review of basic ventilation terms Fraction of inspired oxygen (Fio2) Percent of atmospheric pressure (760 mm Hg) that is O2. For simplicity, documented as Fio2, use the decimal (0.21). Range from 21% to 100%. Peak inspiratory pressure (PIP) Peak pressure measured when the tidal volume is pushed into the airways. The value is also called peak airway pressure (PAP). Value used to set high-pressure and low-pressure alarm limits. In normal lungs (resistance and compliance normal) less than 35 cm H2O. In any condition that increases resistance or decreases 0 compliance, may be greater than 35 cm H2O. Dr. Rana Al Awamleh, Hanadi Yousef 27 Review of basic ventilation terms Mean airway pressure Average proximal airway pressure during the entire respiratory cycle; a major determinate for oxygenation and a focus for the settings of alternative ventilation Dr. Rana Al Awamleh, Hanadi Yousef 28 Invasive mechanical ventilation When endotracheal intubation is required , the oral route is generally preferred to nasal, to reduce incidence of sinusitis. After intubation, the nurse or respiratory therapist should do the following: a 1. Confirm the placement of the ET tube using a CO2 detector and then auscultate for bilateral breath sounds. 2. Mark and chart the centimeter mark on the tube using the teeth as a reference point. 3. Secure the tube to the face and head. o 4. Cut/shorten the tube to reduce dead space, taking care not to cut the pilot balloon, so only 4 cm protrudes from the teeth. 5. Over the next 4 hours, monitor for the development of a life-threatening tension pneumothorax, by assessing for hypoxia, bradycardia, tachycardia, and moderate to life-threatening hypotension Dr. Rana Al Awamleh, Hanadi Yousef 29 REASONS TO CONSIDER INTUBATION 000 1. Severe acidosis or hypoxemia 2. Severe dyspnea 3. Respiratory arrest of 4. Cardiovascular instability 5. Aspiration risk 6. Recent facial trauma Dr. Rana Al Awamleh, Hanadi Yousef 30  Basic ventilation modes will be discussed in the lab sessions Dr. Rana Al Awamleh, Hanadi Yousef 31  Complications related to mechanical ventilation Barotrauma, volutrauma, and pneumothorax Barotrauma can occur when ventilatory pressures increase intrathoracic and intrapleural pressures, causing damage to the lungs, the major vessels, and possibly all organs in the thorax, with referred damage to the abdomen. If severe, barotrauma can lead to pneumothorax: a partially or totally collapsed lung. Symptoms vary depending on the amount of lung collapsed. Tension pneumothorax This develops when pressurized air escapes from the lungs and enters and collects in the thoracic cavity, causing one or both lungs to collapse. High pressure from mechanical positive-pressure ventilation may tear diseased or fragile lung tissue, leading to this life-threatening complication. Symptoms include: respiratory distress, fluctuations in BP, and shifting of the trachea toward the unaffected side. Dr. Rana Al Awamleh, Hanadi Yousef 32  Complications related to mechanical ventilation HIGH ALERT! If tension pneumothorax is suspected, the patient should be disconnected from the ventilator immediately and ventilated using a bag/valve/tube device (Ambu bag). While the primary nurse/therapist is using tube/mask ventilation, others will facilitate an emergency physician call and set up the patient for immediate chest tube insertion/placement. Ventilator-associated pneumonia (VAP) Patients with mechanical ventilation are at high risk for developing (VAP) Use of contaminated equipment/supplies, inadequate hand washing, or poor infection control practices may directly inoculate the tracheobronchial tree with pathogens. Dr. Rana Al Awamleh, Hanadi Yousef 33  Causes of high-pressure alarms during mechanical ventilation D Increased airway resistance D Decreased lung compliance a Patient requires suctioning Pneumothorax Kinks in ventilator circuitry Pulmonary edema Water or expectorated secretions in circuitry Atelectasis Patient coughs or exhales against ventilatory Worsening of underlying disease breaths process Dr. Rana Al Awamleh, Hanadi Yousef 34  CAUSES OF LOW-PRESSURE ALARMS Patient disconnected from machine ① Leak in airway cuff 0 Insufficient air in cuff ⑦ - Hole or tear in cuff D Leak in one-way valve of inflation port Leak in circuitry ⑥Poor fittings on water reservoirs - ⑦ - 0 - Dr. Rana Al Awamleh, Hanadi Yousef 35  Care plans for mechanical ventilation discussed in your text book page 278 Baird M, (2015). Manual of Critical Care Nursing: Nursing Interventions and Collaborative Management. (7th Ed), Mosby Dr. Rana Al Awamleh, Hanadi Yousef 36  Neurological HM Assessment of Patients in Neurological Emergency Neuro- critical care focuses on the care of critically ill patients with primary or secondary neurosurgical and neurological problems and was initially developed to manage postoperative neurosurgical patients. Dr. Rana Al Awamleh, Hanadi Yousef 37  Indication for NHM Some diseases need immediate action, so admission to the NICU is the best solution when there is: 1. Impaired level of consciousness. 2. Progressive respiratory impairment or the need for mechanical ventilation in a neurological patient. 3. Status epilepticus or prolonged seizures. 4. Clinical or Computed Tomographic (CT) evidence of raised Intracranial Pressure ( ICP ), whatever the cause (space occupying lesion, cerebral edema or hemorrhagic conversion of a cerebral infarct, intracerebral hemorrhage, etc.) 5. Need for monitoring (for example, level of consciousness, ICP , continuous electroencephalography ( EEG ) Dr. Rana Al Awamleh, Hanadi Yousef 38 Neurologic screening assessment Neurologic screening assessment includes six major components of the neurologic exam , namely: 1) Mental status 2) Cranial nerve exam 3) Motor exam 4) Reflexes 5) Sensory exam 00 6) Evaluation of coordination and balance. Based on the chief findings of the screening assessment, further evaluation or investigations can be then decided upon. Dr. Rana Al Awamleh, Hanadi Yousef 39 Neurologic screening assessment Pupillary size must be documented. Asymmetry in pupils of less than 1 mm is not significant. Significant difference in pupil size suggests nerve compression due to aneurysms or due to cerebral herniation , in patients with altered mental status. Bilateral pupillary dilation is seen with prolonged anoxia or due to drugs ( anticholinergics ), Bilateral pupillary constriction is seen with pontine hemorrhage or as the result of drugs (e.g., opiates, clonidine ). Dr. Rana Al Awamleh, Hanadi Yousef 40  Neurologic screening assessment EEG Brain CT Scan Brain MRI Others Dr. Rana Al Awamleh, Hanadi Yousef 41 Organ and Tissue oxygenation Organ-specific Measures Urine flow A sensitive indicator of renal perfusion provided the kidneys aren’t damaged Normal is 0.5-1.5 ml/kg/hour Core-peripheral temperature The gradient between peripheral (skin) temp and core (rectal) is often used as an index of peripheral perfusion The less perfusion, the colder the periphery Dr. Rana Al Awamleh, Hanadi Yousef 42 Nursing Considerations in Hemodynamic Monitoring To ensure accuracy of the hemodynamic values obtained from any transducer system. the nurse must level and zero the system as follows: Leveling is performed to eliminate the effects of hydrostatic pressure on the transducer. It should be done before and after connecting the pressure system to the patient, with every change in bed height or changes in the elevation of the head of the bed, with any significant change in patient’s hemodynamic variables, and prior to zeroing and calibration. Zeroing is performed to eliminate the effects of atmospheric pressure on the transducer. All values should be rated at the end of expiration. The transducer should be leveled visibly with static axis. The transducer should be leveled, is a road, and calibrated every eight hours depending on institutional policy. Readings can be taken with ahead a bed elevated, as long as a transducer is leveled to the plane to static axis. Readings cannot be taken with a patient and a lateral position. Dr. Rana Al Awamleh, Hanadi Yousef 43  Morton P, Fontaine. (2017) Critical Care Nursing: A Holistic Approach. (7th Ed.), LWW Sole, M., Klein, D. & Mosely, M. (2016). Introduction to Critical Care Nursing. (7th Ed.), References St Louis: Saunders. Baird M, (2015). Manual of Critical Care Nursing: Nursing Interventions and Collaborative Management. (7th Ed), Mosby Dr. Rana Al Awamleh, Hanadi Yousef 44