A&T Study Guide (1)

Page 1: Assessment of Cardiac and Pulmonary Function

Cardiac Diseases

• Cardiac diseases can arise from any layer of the heart.

Cardiac Cycle

• Defined by valve closure, consisting of:

  • Stage 1: Late Diastole

    • Mitral and Tricuspid valves open; aortic and pulmonary valves closed.

    • Ventricular filling occurs mostly passively; atrial kick provides final active push.

  • Stage 2: Early Systole

    • Isometric ventricular contraction; all valves closed.

  • Stage 3: Late Systole

    • Mitral and Tricuspid valves closed; aortic and pulmonary valves opened for rapid ejection of blood from ventricles.

  • Stage 4: Early Diastole

    • Isometric ventricular relaxation; all valves closed; atrial filling occurs.

• The cycle is driven by pressure differences among chambers.

• Typical pressures:

  • Right and Left atria: similar pressure.

  • Left ventricle > Right ventricle; Aorta > Pulmonary artery.

• Valve closure occurs when ventricular pressure increases:

  • Mitral & Tricuspid close when pressure exceeds, while aortic and pulmonary close when pressure drops.

Electrical Activity of the Heart

• P wave: Precedes atrial contraction.

• QRS complex: Precedes ventricular contraction.

• T wave: Represents repolarization.

• Heart sounds correspond to valve closures:

  • S1: Closure of Mitral & Tricuspid valves.

  • S2: Closure of Aortic & Pulmonary valves.

Cardiac Output Calculation

• Average stroke volume at rest: 70ml.

• End Systolic Volume (ESV): 50ml.

• End Diastolic Volume (EDV): 120ml.

• Cardiac Output (CO):

  • Formula: CO = HR * SV (Normal: 5-6 L/min).

  • Ejection Fraction: SV/EDV (Normal > 55%, Reduced < 40%).

• Factors affecting cardiac output: Heart Rate (HR), Stroke Volume (SV).

• Stroke Volume influenced by:

  • Contractility (ionotropic drugs), Preload (venous return), and Afterload (vascular resistance).

Modulating Heart Rate

• Dominantly regulated by the SA Node (60 bpm).

• Autonomic Nervous System (ANS) influences:

  • SNS: increases HR.

  • PNS: decreases HR.

Modulating Stroke Volume

• Factors include:

  • Contractility: Medications can influence ionotropic capacity.

  • Preload: Managed by venous return pressure; affects filling.

  • Afterload: Inverse relationship with SV; managed by vasodilators to decrease BP.

Pulmonary Review

• Focuses on ventilation aspects.

Page 2: Pulmonary Function Review

Muscles of Ventilation

• Inspiratory Muscles:

  • Primary: Diaphragm and Intercostals.

  • Secondary: Scalenes and SCM.

• Expiratory Muscles: Generally passive; Active expiration involves internal intercostals.

Lung Compliance

• Compliance calculation: C = change in Volume / change in pressure.

• Chest wall and lungs move together through pleural membranes.

Lung Volumes and Definitions

• Key Lung Volumes:

  • Tidal Volume, Vital Capacity, Residual Volume, etc.

  • Differences in obstructive vs restrictive diseases:

    • Obstructive: Decreased Vital Capacity (VC), increased Residual Volume (RV).

    • Restrictive: Decreased VC and RV.

Control of Ventilation

• Chemoreceptors:

  • Peripheral: Carotid bodies respond to changes in O2, CO2, pH.

  • Central: Medulla responds to pH.

• Ventilation increases with activity due to sensory input and mechanical feedback.

• Pulmonary stretch receptors regulate breathing patterns based on lung stretch.

Gas Exchange and Transport

• Gas exchange occurs in the alveoli through diffusion, relying on:

  • Partial pressure gradients in air and blood.

  • Short distance between alveoli and capillaries.

• Oxygen Transport:

  • 98% bound to hemoglobin in RBCs; 2% dissolved in plasma.

• CO2 Transport:

  • Primarily in bicarbonate form; some dissolved or bound to hemoglobin.

Perfusion

• Typically 5 L/min oxygenated blood flows through the lungs.

• Pulmonary artery pressure is around 15 mmHg.

• Blood flow in upper lung zones varies with gravity factors.

Functional Outcome Measures

• Standardized assessments to document patient progress.

• Common CVP Outcome Measures:

  • AMPAC 6-Clicks, SPPB, TUG, etc.

• Walking speed cutoffs:

  • < 0.8 m/s indicates functional impairment;

  • 1.3 m/s needed for community ambulation.

Page 3: Cardiac Assessment Methods

Overview of Cardiac Assessment

• Assessment includes:

  • Chart Review, Risk Factor Analysis, Subjective and Objective Exams.

Chart Review Elements

• Examine: PMH (Past Medical History), EKG, medications, lab results, imaging studies.

Risk Factor Analysis

• Common cardiac risk factors:

  • Conditions: Sedentary lifestyle, DM, high stress.

  • Lifestyle: Smoking, high blood lipids, family history.

  • Physical: Altered sex hormone levels, age, low vitamin D, inadequate diet.

Subjective Examination

• Assess symptoms such as:

  • Angina, heart palpitations, fatigue, shortness of breath, etc.

  • Consider pain, mobility levels, home setup, and use of assistive devices (AD).

Objective Examination

• Perform screening tests:

  • Strength, ROM, sensory, balance, mobility, and gait assessment.

• Monitor vital signs:

  • HR, BP, weight, and peripheral pulses.

  • Evaluate edema: Pitting vs. Non-pitting, significant shifts signal fluid status change.

Auscultation Techniques

• Proper technique for heart sounds:

  • Use bell/diaphragm for proper listening; avoid clothing interference.

• Key auscultation areas:

  • Aortic area (R sternal border, 2nd rib): S2.

  • Pulmonic area (L sternal border, 2nd rib): P2.

  • Tricuspid area (R sternal border, 5th rib): T2.

  • Mitral Area (L midclavicular line, 5th rib): M1.

Abnormal Heart Sounds

• S3: Occurs in early diastole; indicates decreased ventricular compliance.

• S4: Occurs in late diastole; suggests turbulence from extra atrial contraction.

Assessment Techniques for Exercise Testing

• Treadmill testing: Utilize Bruce protocol or submaximal testing.

• Walking tests such as 6MWT or 2MWT to assess functional capacity.

Patient Reported Outcomes

• Utilize tools like the Minnesota Living with HF or Chronic HF Questionnaire for subjective measurements.

Page 4: Pulmonary Assessments

Ineffective Cough

• Indicates increased risk for pulmonary infections.

• Populations at risk: post-surgical patients, those with neuromuscular disorders.

Cough Mechanisms

• Function: Clears airways by high-velocity exhalation; a reflex.

• Cough Duration Classifications:

  • Acute:

  • Subacute: 8 weeks (GERD, chronic bronchitis).

Cough Phases

• Irritant Receptors: Located in trachea, pharynx, and larger airways; respond to stimuli.

• Afferent Pathway: Peripheral receptors to medulla/pons respiratory centers.

• Efferent Pathway: Medullary signals activating expiratory muscles.

Inspiratory Phase

• Involves up to 85-90% of inspiratory capacity, about 2.3L of air.

• Interventions: Utilize spirometers to enhance inspiratory capacity.

Cough Techniques

• Cover hold phase using the epiglottis to prevent airflow.

• Force Production: Isovolumetric contraction of expiratory muscles.

• Training to improve cough force through muscle recruitment.

Expulsion Phase

• Glottis opens; high-pressure air is released, moving secretions upward.

• Encourage patients to sustain expectorative efforts.

Page 5: Treatment Impact of Heart Disease

Consequences of Heart Disease

• Results in:

  • Impaired aerobic capacity and enduring fatigue.

  • Compromised pulmonary function and gas exchange.

  • Altered autonomic nervous system function affecting heart rate and contractility.

Identifying Impairments

• Common impairments include:

  • Dyspnea, fatigue, reduced exercise tolerance.

  • Functional limitations (walking, stairs, etc.) and disabilities (travel/work limitations).

Treatment Interventions

• Examples of interventions:

  • Supplemental O2, breathing exercises, strength training, gait training.

  • Referral to occupational therapy (OT) and social work.

Outcome Measures

• Essential for guiding intervention effectiveness.

• Example: Short Physical Performance Battery: Evaluate functional mobility and strength; low scores imply risks.

Considerations for Exercise

• Start and progress exercise based on:

  • Ability to converse without dyspnea (RR<30), moderate fatigue.

  • Signs for exercise modification include pallor, confusion, and heart sound changes.

Treatment in Acute Care

• Prioritize functional recovery, include education, EKG monitoring, and vital sign observation.

Cardiac Rehabilitation

• Must be medically supervised with immediate support available.

• Approved diagnoses include post-MI, CABG, stable angina, etc.

• Program includes nutritional counseling and psychosocial support, structured exercise over 36 sessions.

Pulmonary Interventions

• Focus on mobilization based on individual impairments.

Page 6: Supplemental Oxygen and Breathing Exercises

Supplemental Oxygen Delivery

• Considered a medication; adjust humidity and flow.

• Key metrics include:

  • PH2O: Humidity of air.

  • FiO2: Fraction of inspired oxygen - higher than 30% requires humidity.

• PaCO2: Monitored during activity.

• PT's role includes titration and device management.

Delivery Devices Overview

• Nasal Cannula: 1-6L; minimal oxygen increase.

• Face Mask: 5-10L; variable FiO2.

• Non-Rebreather Mask: 10-15L; provides high concentrations of O2.

• BiPAP/CPAP: Provides positive airway pressure during inspiration/exhalation.

Inspiratory Breathing Exercises

• Designed to improve lung capacity and ventilation efficiency.

• Diaphragmatic breathing: Focus on prolonging inhalation while reducing work of breathing.

  • Involve inspiratory pauses to maximize air exchange.

Techniques for Breathing Exercises

• Stacked Breaths: Gradual inhalation leads into a big exhalation to improve ventilation.

• Progressive Volume Breaths: Gradual increase in volume inhaled.

• Facilitated Segmental Breathing: Encourages lung expansion in specific chest areas.

Expiratory Breathing Exercise

• Objectives include increasing expired volumes and maintaining positive airway pressures during exhalation.

• Pursed Lip Breathing: Enhances pressures during exhalation.

Muscle Strengthening Techniques

• Inspiratory Training: Enhance diaphragm/external intercostal function.

• Expiratory Training: Focus on internal intercostals to improve respiratory strength using devices.

Page 7: Airway Clearance Techniques

Overview of Airway Clearance

• Strategies to remove excessive pulmonary secretions.

• Goals include:

  • Reduce obstructions and re-expand collapsed lungs.

Postural Drainage Techniques

• Involve gravity-assisted drainage; may combine with pharmacological aids.

• Precautions include monitoring blood pressure and oxygen saturation.

Cough Techniques for Secretion Clearance

• Functional Cough: Basic reflex to clear airways.

• Huff Cough: For patients in pain; promotes slower exhalation.

• Stacked Cough: Series of breaths followed by a deep cough.

  • Useful for patients with pain-related challenges.

Assisted Coughing Techniques

• Treatment for patients with ineffective cough due to neuromuscular conditions.

• Techniques including anterior chest compression and self-assisted abdominal thrusts.

Breathing Strategies for Airway Clearance

• Autogenic Drainage: Series of breathing phases designed for mobilizing secretions.

• Active Cycle of Breathing: Alternating breathing phases to promote secretion clearance.

Manual Techniques for Secretions

• Percussion: Inform about sputum loosening techniques with protective measures.

• Vibration: During exhalation to aid mucociliary transport after percussion.

• Rates of application vary based on patient needs.

Precautions and Contraindications

• Contraindications may include fractures, lung cancer, unstable cardiovascular conditions, etc.

Page 8: Advanced Airway Management

Mechanical Ventilation considerations

• Always follow nursing protocols; never alter ventilation settings directly.

Assessment of Breathing Techniques

• Technique efficacy is vital to patient recovery and lung health optimization.

Assessment Devices Overview

• P&V Devices: For airway maintenance and suctioning of secretions in required situations.