Midterm Study Guide

Hemodynamic Monitoring & Support Devices

📍 Arterial Lines

• Leveling: Transducer at 4th ICS, mid-axillary line (phlebostatic axis = right atrium = best place to get a reading and zero out device)

  • Radial is easiest access point for transducer
    

• Purpose: Continuous BP monitoring, frequent ABGs

• Complications: Infection, bleeding, thrombosis, neurovascular injury
  

📊 Square Wave Test

Assesses the accuracy and functionality of an arterial blood pressure monitoring system. Checks if fluid is properly transmitted to transducer.

Steps: Rapid flush (creates square) → observe waveform → interpret

💧 Central Venous Pressure (CVP)

• Normal: 2–8 mmHg

• High (>13–15): Hypervolemia / RV failure → Diuretics (Lasix)

• Low (<2): Hypovolemia → Fluids
  

❤ LVAD (Left Ventricular Assist Device)

• Purpose: Pumps blood from LA → aorta (supports LV)

• ⚠ Safety: If battery dies → patient dies

• Patient Teaching:

  • Carry spare batteries + charger at all times

  • Know how/when to change batteries (before alarm)

  • Avoid water immersion

  • Have emergency contact info ready

CAD, Angina, ACS, & MI

🚨 Not All Chest Pain = MI

• May see cold, clammy, ashen/gray skin from vasoconstriction

• Other causes: angina, anxiety, GI, pulmonary

• Always: ECG + troponins + full assessment
  

💢 Angina Quick Table

Key: Angina = no cardiac cell death → no troponin rise

📊 STEMI vs NSTEMI

🧪 Troponins

• Draw ASAP in suspected MI

• ↑ = STEMI or NSTEMI

• Normal = angina

💊 Nitrates

Action:

• Vasodilate → ↑ coronary blood flow, ↓ afterload, ↓ O₂ demand
  

Side Effects (too much): Hypotension, headache

Education:

1. Sit/lie down before taking

2. 1 dose → wait 5 min

3. No relief after 3 doses (15 min) → call 911

4. Keep in dark glass container/same container, replace q6mo

5. No PDE-5 inhibitors (Viagra, Cialis)
   

🩺 Modifiable CAD Risks

• Hypertension

• Smoking

• Hyperlipidemia

• Obesity

• Inactivity

• Diabetes control

Congestive Heart Failure (CHF)

🩺 S/S of CHF

• Chest pain

• SOB / orthopnea

• Dizziness / lightheadedness

• Swelling (edema)

• Sudden weight gain

• Fatigue / weakness
  

• Assessment Findings:

  • Crackles in lungs

  • S3 heart sound

  • Tachycardia

  • Hypotension (late, when heart can’t compensate)

  • Hypervolemia

• Treatment:

  • Diuretics (first check potassium)

⚠ Common Reasons for Readmission

• Noncompliance (not taking meds as prescribed)

• Wrong meds or incomplete discharge orders

• Cannot afford meds
  

📏 Patient Education

• Daily weights — report >2 lb in 1 day or >5 lb in 1 week

• Low sodium diet — ≤2 g/day

• Fluid restriction — ≤2 L/day
  

🔄 Compensation Mechanisms in CHF

• SNS activation → ↑ HR, ↑ contractility, vasoconstriction

• RAAS activation → ↑ sodium & water retention → ↑ preload

• Ventricular remodeling → dilation & hypertrophy (long-term damage)

💊 Medications for HF Patients

Dysrhythmias & Lethal Rhythms

💀 Lethal Rhythms

📌 Other Key Dysrhythmias

Synchronized Cardioversion vs. Defibrillation

If PT has pauses in the heart on monitor -> anticipate pacemaker. 

AAA, TAA, & Dissection

🔍 Key Definitions

• AAA (Abdominal Aortic Aneurysm) – Bulge in abdominal aorta

• TAA (Thoracic Aortic Aneurysm) – Bulge in thoracic aorta

• Dissection – Tear in aortic intima → blood enters media → separation of layers
  

🕒 Assessment

• Any aneurysm: Assess q6–12 hrs for changes

• Goal: Detect expansion or rupture early
  

⚠ Predisposing Factors

• Older age

• Hypertension

• Atherosclerosis

• Genetic connective tissue disorders (Marfan, Ehlers-Danlos)
  

📍 AAA Specifics

• Clue: No circulation below diaphragm → Blue Toe Syndrome (poor perfusion to legs)

• Possible abdominal bruit

• Pulsatile abdominal mass (don’t palpate vigorously!)
  

📍 TAA Specifics

• Compresses airway/lungs → cough, dyspnea

• May cause hoarseness, dysphagia if compressing recurrent laryngeal nerve/esophagus
  

💥 AAA Rupture

• Grey Turner’s Sign → flank bruising from retroperitoneal bleed
  

💢 Dissection

• Symptoms:

  • Sudden, severe tearing/ripping back pain

  • Hypotension/weakness

  • Muffled heart sounds (possible pericardial tamponade)

• Intervention: Emergency surgery ASAP
  

🫀 Treatment for Any Aneurysm

• Control BP & HR to reduce aortic wall stress

  • β-blockers, vasodilators as ordered

• Surgery if:

  • Symptomatic

  • Rapidly expanding

ABGs, ARDS, ARF, Respiratory Failure

📊 ABG Basics

🧮 Interpreting ABGs

1. Look at pH – Acidotic (<7.35) or alkalotic (>7.45)?

2. Look at PaCO₂ – If abnormal in opposite direction of pH → respiratory cause.

3. Look at HCO₃⁻ – If abnormal in same direction as pH → metabolic cause.

4. Compensation:

   • Uncompensated – opposite value normal

   • Partially compensated – opposite value abnormal but pH still abnormal

   • Fully compensated – opposite value abnormal but pH normal

📍 Acid-Base Types

🫁 Respiratory Failure

• PaO₂ <60 mmHg (hypoxemia) and/or PaCO₂ >45 mmHg (hypercapnia)

• Types:

  • Hypoxemic → Low O₂, normal/low CO₂ (O₂ problem)

  • Hypercapnic → High CO₂ (ventilation problem)

🔴 Hypercapnic Respiratory Failure

• Cause: Hypoventilation, airway obstruction, neuromuscular weakness

• On vent: ↑ Peak Inspiratory Pressure (PIP) = bad (obstruction, bronchospasm, kinked tube, mucus plug)

• Fix: Suction, check tubing, bronchodilators

💥 ARDS (Acute Respiratory Distress Syndrome)

• Cause: Inflammatory injury to alveoli → ↑ permeability → pulmonary edema

• Criteria:

  • Acute onset

  • Refractory hypoxemia

  • PaO₂/FiO₂ ratio ≤300

• Treatment:

  • Low tidal volume ventilation

  • ↑ PEEP

  • Prone positioning

  • Treat cause

Airway & Ventilator Management

🛡 VAP (Ventilator-Associated Pneumonia) Bundle

• HOB ≥30° (prevent aspiration)

• Oral hygiene (chlorhexidine rinse per protocol)

• Suction as needed (keep airway clear, prevent micro-aspiration)

• Daily sedation vacation & readiness-to-wean assessment (if protocol)
  

💢 If Pt is “Fighting the Vent”

• If necessary → Paralytic (neuromuscular blocker) per order to improve synchrony with ventilator

• Always pair paralytics with sedation & analgesia

🚨 Sudden Respiratory Distress on Vent

Steps:

1. Remove from ventilator

2. Manually ventilate with Ambu bag + 100% O₂

3. Call for help 

Bad Respiratory Pattern: 

• Apneustic (spaced mountains) -> caused by brain stem injury/lesion or CVA
  

Acute Intracranial Problems

🧮 Key Formulas

• CPP (Cerebral Perfusion Pressure) = MAP − ICP

  • Normal CPP: 60–100 mmHg

  • <50 mmHg: Ischemia risk

  • <30 mmHg: Incompatible with life
    

• MAP (Mean Arterial Pressure) = (SBP + 2 × DBP) ÷ 3
  

⚠ Signs of Increased ICP

• Halo Sign: Clear/yellow CSF ring around blood on dressing

• Battle Sign: Bruising over mastoid (possible basilar skull fracture).

• Cushing’s Triad:

  • Widened pulse pressure

  • Bradycardia

  • Irregular respirations
    

📊 Glasgow Coma Scale (GCS)

• Mild: 13–15

• Moderate: 9–12

• Severe: <8 → consider intubation
  

💥 Management of High ICP

• Surgical: Craniotomy if indicated

• Medical: Mannitol (osmotic diuretic) to pull fluid from brain

• Positioning: HOB 30°, neck neutral/midline

• Environment: Calm, minimal stimulation

• Avoid: Coughing, straining, Valsalva

• Temp control: Prevent fever (↑ metabolic demand)

• Ventilation: Keep CO₂ in normal range (hypercapnia → vasodilation → ↑ ICP)

Spinal Cord Injuries (SCI)

1. Causes of Spinal Cord Injuries

• Violence (e.g., gunshots, stab wounds)

• Sports injuries (contact sports, tackles)

• Diving accidents (hitting head on shallow water)

• Falls (especially in elderly or high falls)
  

2. Types of SCI Injury

• Primary Injury:

  • Direct trauma to spinal cord

    • Penetrating (stab, bullet) or blunt trauma (impact, compression)

  • Immediate damage
    

• Secondary Injury:

  • Progressive damage after primary injury

    • Inflammation, ischemia, edema cause further permanent damage

  • Monitor carefully for worsening neuro status
    

3. Most Unstable Injury

• Flexion-Rotation injury = Most unstable spinal injury
  

4. Respiratory Concerns in SCI

• Cervical injuries (C1–C8) especially risky for breathing

• Higher cervical lesions → respiratory muscle paralysis (diaphragm, intercostals)
  

5. Autonomic Dysreflexia (AD)

• Occurs in SCIs above T6 and can lead to a life-threatening hypertensive crisis if not managed properly.

• Avoid: Full bladder, bowel impaction, tight clothing, SCDs, pain stimuli

• Symptoms:

  • Sudden hypertension (↑BP)

  • Flushing above injury level (facial)

  • Bradycardia (slow HR)

  • Headache, sweating
    

• Emergency!

  • Sit patient up

  • Remove triggering factors immediately

  • Catheterize bladder if needed

  • Notify provider promptly
    
    

6. Cauda Equina Syndrome (CES)

• Injury below L1–L2 (nerve roots, not spinal cord itself)

• Symptoms:

  • Complete sensory loss in saddle area (between legs, buttocks, inner thighs, back of legs)

  • Asymmetric lower extremity weakness & pain

  • Bowel/bladder dysfunction (urgent!)

• Needs urgent surgical decompression
  
  

7. Guillain-Barré Syndrome (GBS)

• Autoimmune ascending paralysis (starts in legs → moves up)

• Severe respiratory muscle weakness → monitor closely

• Treatment: IV Immunoglobulins (IVIG) or plasmapheresis

Cranial Nerves

Assessments:

• CN I Olfactory (Smell)

  • Assessment: Close 1 nostril and identify familiar scents.

• CN II Optic (Vision)

  • Assessment:

    • Visual Field: Ask pt to look at bridge of your nose and indicate when object from periphery is seen (peripheral vision).

    • Visual Acuity: Ask pt to read Snellen chart.

• CN III (Oculomotor), CN IV (Trochlear), CN VI (Abducens)

  • Assessment: Ask pt to hold head steady and assess extraocular muscles by moving finger in 6 directions and PERRLA (Pupils Equal, Round, Reactive to Light & Accommodation)

• CN V Trigeminal (facial sensation/corneal reflex/chewing)

  • Assessment: Ask pt to close eyes and identify light touch & pinpricks on face, clench teeth and assess strength

• CN VII Facial (Facial expression/taste anterior 2/3 tongue)

  • Assessment: Ask pt to raise eyebrows, close eyes tightly, purse lips, smile & frown. Taste test (sweet/salty).

• CN VIII Vestibulocochlear (hearing/balance) → Sensory

  • Assessment:

    • Hearing: Ask pt to close eyes and indicate when he/she hears rustling of fingertips.

• CN IX Glossopharyngeal (swallowing/gag reflex/taste posterior ½ tongue) and CN X Vagus (Parasympathetic to heart, lungs, digestive system, gag reflex)

  • Assessment: Gag reflex

• CN XI Accessory (Sternocleidomastoid/neck and trapezius muscle movement) → Motor

  • Assessment: Shoulder shrug and turns head side-to-side against resistance.

• CN XII Hypoglossal (Tongue movement) → Motor

  • Assessment: “Stick out your tongue” and push tongue side-to-side against resistance from a tongue blade.

Stroke