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INTRODUCTION

Test Taking Tips

  • Critical care problems generally can be solved by applying physiology and pharmacology principles to the question (or patient).

  • Understanding the sympathetic and parasympathetic nervous system assists in the diagnosis of cardiac issues and their treatment.

  • Understanding respiratory physiology and mechanics greatly assists in solving ventilator-related questions.

HEMODYNAMIC PARAMETERS

What is the formula for mean arterial pressure (MAP)?

  • MAP = DBP + 1/3 × (SBP − DBP)

What is the normal range for cardiac output (CO)?

  • 4 to 8 L/min

What is the normal range for the cardiac index (CI)?

  • 2.5 to 4 L/min

What is the normal range for systemic vascular resistance (SVR)?

  • 800 to 1400 dyn · s/(cm5)

What is the normal range for the SVR index (SVRI)?

  • 1500 to 2400 dyn · s/(cm5)

What is the normal range for pulmonary capillary wedge pressure (PCWP)?

  • 7 to 15 mm Hg

What is the normal range for central venous pressure (CVP)?

  • 2 to 6 mm Hg

What is the normal range for pulmonary artery (PA) pressure?

  • 20 to 30/6 to 15 mm Hg

What is the normal range for mixed venous oxygen saturation (SvO2)?

  • 70% ± 5%

What is SvO2?

  • The oxygen saturation of blood in the right ventricle/pulmonary artery that serves as an indirect measure of peripheral oxygen supply and demand

What factors influence SvO2?

  • Oxygen delivery and oxygen extraction

Approximate percentage of CO that goes to the kidney:

  • 25%

Approximate percentage of CO that goes to the brain:

  • 15%

Approximate percentage of CO that goes to the heart:

  • 5%

INVASIVE MONITORING

What complications can occur during central venous catheter placement?

  • Arterial puncture, air or catheter embolism, dysrhythmias, hemorrhage or arteriovenous fistulization, pneumothorax, pseudoaneurysm formation

What should you immediately do if a patient receives an air embolus?

  • Roll the patient to the left and place them head down to keep air in right atrium/ventricle; attempt to aspirate air with central catheter/pulmonary artery catheter

Relative contraindications for pulmonary artery catheter placement:

  • Left bundle branch block, previous pneumonectomy

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