Complex Midterm

Modules 1-5

Physical Indicators of Perfusion

Brain = LOC

Body = Pulses, Cap refill, skin color + temp

Organs = Urine output

Elements of Stroke Volume

Preload

Afterload

Contractility

Preload

End diastolic volume of ventricles

CVP

Central Venous Pressure

Right heart preload

Measured via PA line PROXIMAL port and Central Line

PAOP/PAWP

Pulmonary Artery Occlusive/Wedge Pressure

Left heart preload

Measured via PA line DISTAL port with balloon inflated

Afterload

Resistance the ventricles pump against

SVR

Systemic vascular resistance

Afterload for left ventricle

PVR

Pulmonary Vascular Resistance

Afterload for right ventricle

Ejection Fraction

% of blood ejected from ventricles upon contraction

<50% HF

55-70% Healthy

4 Lumens of PA Line

Proximal

Distal

Balloon

Thermistor

PA Line - Proximal Port

Placed in Right Atrium

Measures CVP, ScvO2

PA Line - Distal Port

Placed in pulmonary artery

Measures SvO2, PAWP/PAOP with balloon inflated

PA Line - Thermistor

Measures CO via temperature changes

ScvO2

O2 saturation of upper body’s deoxygenated blood returning to heart

Upper body = brain, head, arms, neck, chest

Slightly higher number than SvO2

Measured via central line (truer read) and PA line PROXIMAL port

SvO2

O2 saturation of mixed venous return from entire body

Measured via PA line DISTAL port

Central Line measures

ScvO2

CVP

Measures of Oxygen Delivery

Cardiac Output

ABG

• Hemoglobin

• SaO2 (Arterial Oxygen Saturation) - 97% delivery

• PaO2 (Oxygen dissolved in plasma) - 3% delivery

Healthy SaO2

95-100%

SpO2 estimates this value

Healthy PaO2

75-100 mmHg

Healthy SvO2 and ScvO2 values

ScvO2: 70-80%

SvO2: 65-75%

How do you calculate a HR using a 6 second ECG strip?

Number of QRS complexes in 6 sec strip x 10

OR

1500/small boxes btwn R waves

- 500/large boxes btwn R waves

P wave

Atrial depolarization

Impulse from SA → AV node

P-R Interval

Time for atria to depolarize and contract

.12-.2 sec (about 1 medium box)

(From beginning of P wave to downward curve of Q)

QRS Complex

Ventricular depolarization + Atrial repolarization

<.1 sec (half of a medium box)

ST Segment

Ventricular contraction

(Bottom of S to where T starts to bump up)

T Wave

Ventricular repolarization

U wave

Rare (digoxin tox or hypokalemia)

Purkinje fiber repolarization

QT Interval

<.44 sec

Shows us time for ventricles to reset

(From end of P wave to end of T wave)

QT Prolongation

Dangerous if >.5

Congential issue, meds, hypokalemia

Pacing Issues

Failure to fire

Loss of capture

Undersensing

Normal Sinus

Sinus Arrhythmia

• Irregular rhythm

• D/t regular breathing, sleep apnea, sick sinus syndrome

Sinus Bradycardia

• Rate <60 bpm

• D/t hypoxia, hypothermia, meds, sleep, athletes

• Treatment

  • Symptomatic: Atropine + treat cause (emergent), pacing (non-emergent)

  • Asymptomatic: Address cause, monitor

Sinus Tachycardia

• Rate >100 bpm

• D/t fever, compensation (anemia/hypovolemia/hypotension), PE, MI

• Treatment

  • Treat the cause + meds (Beta Blockers, CCBs)

Tachyarrhythmias must be cardioverted

Idioventricular Rhythm

• Ventricles acting as pacemaker

• Slow rates typically

• No P wave, wide QRS

• Causes: MI, meds, toxicity, electrolytes, congenital

• Treatment

  • Pulse: Treat cause + Pace +Atropine

  • Pulseless: CPR

AFib

• No P waves, rates vary, no regular rhythm

• Causes: aging, chronic conditions

• Complications: Decreased CO, CLOTS

• Treatment

  • Anti-coagulation, rate control, rhythm control

  • Severe s+s or rate → Cardiovert

Atrial Flutter

• Irregular sawtooth “F” waves

• Rates vary

• Causes: MI, mitral valve disease, COPD

• Treatment:

  • Anti-coagulation, rate control, rhythm control

  • Severe s+s or rate → Cardiovert

Premature Ventricular Contractions (PVCs)

• Wide, irregular QRS complexes that are all unique

• Multiple (3+) could be precursor to VTach

Ventricular Tachycardia (VTach)

• Causes: Hs + Ts

• Treatment

  • Pulse: Treat cause + anti-arrhythmic (amiodarone) + cardiovert

  • Pulseless: CPR + Defib + Epi/Amiodarone

Torsade’s de Pointes

• Rapid, continuously changing QRS complexes with no P waves

• Treat with MAGNESIUM

• Treat like VTach

  • Pulse: Cardiovert

  • Pulseless: CPR + Defib

Ventricular Fibrillation (VFib)

• Coarse or fine

• Causes: Hs and Ts

• Treat: CPR + Defib

Pulseless Electrical Activity

• Treat with CPR + Epi

• Push Epi Always

Asystole

• CPR + Epi!

Hs and Ts: The H’s

Hypoxia

Hypothermia

Hypovolemia

Hydrogen ions (acidosis)

Hypo/hyperkalemia

Hs and Ts: The Ts

Tamponade

Thrombus (PE)

Thrombus (Cardiac)

Tension pneumo

Toxins

Defibrillation Rhythms

VFib

Pulseless VTach

Cardioversion Rhythms

AFib (after anti-coag)

VTach with a pulse

Unstable tachyarrhythmias

Amiodarone

Anti-arrhythmic, reduces HR

For tachyarrhythmias

Atropine

Increases HR

Bradycardias

Adenosine

Converts, slows, stops rhythms

May go into asystole - be careful!

Stages of Shock

Initial

Compensatory

Progressive

Refractory

Initial Stage of Shock

Initial insult, subtle changes in assessment

May see higher lactate

Compensatory Stage

Tachypnea (alkalosis)

Tachycardia

Decreasing BP + UO!

Subtle AMS

Narrowing pulse pressure + weaker pulses

Cool, clammy skin

Progressive Stage

Compensation fails

Blood is shunted to vital organs

Profoundly low BP

Lethargy/coma

Absent bowel sounds, anuria (organs failing d/t no perfusion)

Acidosis d/t anaerobic metabolism

Refractory Stage

Prolonged tissue hypoperfusion —> multi-system organ failure

Peripheral ischemia and necrosis

Irreversible, high mortality rate

MODS

Multiple Organ Dysfunction Syndrome

• Decreased oxygen delivery to organs + higher demand

• Organ dysfunction → organ death

  • Lungs + kidneys usually first to go

  • 1 organ to 3+, mortality rate goes from 40% to 80-90%

• Identify via anuria, respiratory failure, absent bowel sounds

• Treat cause + supportive care

DIC

DIC: Disseminated Intravascular Coagulopathy Flow Overwhelming inflammatory rxn → excess clotting → exhaustion of clotting factors → excess bleeding Looks like…bleeding from unlikely places Labs D Dimer elevated Decreased clotting factors Increased clotting times Increased fibrin degradation products Treatment Supportive care Treat the cause Volume replacement Replace clotting factors Bleeding precautions