NREMT EMT 6: Anatomy, Physiology, and Pathophysiology - Pathophysiology of Respiratory Failure, Hypoxia, Hypercapnia, Ventilatory Failure

What This Is: Respiratory Failure (Hypoxia, Hypercapnia, Ventilatory Failure)

Respiratory failure is when your body can't get enough oxygen or get rid of too much carbon dioxide. Imagine trying to breathe through a straw with a big glob of jam stuck in it – that's what happens when your airways get blocked or your lungs can't work right. This can happen for many reasons, like a heart attack, pneumonia, or a severe allergic reaction. If not treated quickly, it can lead to brain damage or even death.

Key Steps / Core Facts:

• Hypoxia: Low oxygen levels in the blood (normal is 75-100 mmHg). If below 60 mmHg, start oxygen therapy.
• Hypercapnia: High carbon dioxide levels in the blood (normal is 35-45 mmHg). If above 50 mmHg, start ventilation.
• Ventilatory failure: When your lungs can't expand or contract properly. (OPQRSTI: Onset, Pattern, Quality, Region, Severity, Timing, Involvement)
• Respiratory rate: 12-20 breaths per minute (bpm). If above 30 bpm, it may indicate respiratory distress.
• Oxygen saturation: 95-100% (measured by pulse oximeter). If below 90%, it may indicate hypoxia.
• Chest expansion: 1-2 inches (2.5-5 cm) with each breath. If less than 1 inch, it may indicate ventilatory failure.
• Breathing sounds: Normal sounds are "vesicular" (like a gentle breeze). If you hear "bronchial" sounds (like a loud, wheezy hiss), it may indicate airway obstruction.
• Cyanosis: Blue discoloration of the skin and mucous membranes (normal is pink). If present, it may indicate hypoxia.
• Respiratory acidosis: When your blood pH drops below 7.35 (normal is 7.35-7.45). If below 7.25, it may indicate severe respiratory failure.
• Respiratory alkalosis: When your blood pH rises above 7.45 (normal is 7.35-7.45). If above 7.55, it may indicate severe respiratory failure.

What Laypeople Can Do:

• If someone is having trouble breathing, call 911 and stay with them until help arrives.
• If someone is unconscious, check their airway, breathing, and circulation (ABCs) and start CPR if necessary.
• If someone is experiencing severe respiratory distress, try to keep them calm and comfortable until help arrives.

Common Mistakes:

• Mistake: Thinking that a person is just "tired" or "overexerted" when they're actually experiencing respiratory failure.
• Fix: Recognize the signs of respiratory distress (e.g., rapid breathing, blue skin) and call for help.
• Mistake: Not recognizing the signs of respiratory failure in a child or elderly person.
• Fix: Be aware that respiratory failure can present differently in different age groups and populations.
• Mistake: Not using a pulse oximeter to check oxygen saturation levels.
• Fix: Use a pulse oximeter to quickly assess oxygen levels and guide treatment.

Quick Practice Scenarios:

1. A 35-year-old woman is experiencing severe chest pain and shortness of breath. What should you do first?

Answer: Call 911 and try to keep her calm and comfortable until help arrives.

1. A 2-year-old child is having trouble breathing and is making high-pitched sounds. What should you do first?

Answer: Call 911 and check the child's airway, breathing, and circulation (ABCs).

1. A 75-year-old man is experiencing severe respiratory distress and is cyanotic. What should you do first?

Answer: Call 911 and try to keep him calm and comfortable until help arrives.

Last-Minute Exam Cram:

• Normal respiratory rate: 12-20 bpm
• Normal oxygen saturation: 95-100%
• Normal chest expansion: 1-2 inches
• Agonal breathing is NOT normal breathing – start CPR
• Respiratory acidosis is a life-threatening condition – treat with oxygen and ventilation
• Cyanosis is a sign of hypoxia – treat with oxygen
• Respiratory failure can present differently in different age groups and populations
• Normal blood pH: 7.35-7.45
• Severe respiratory failure requires immediate treatment with oxygen and ventilation
• Hypoxia can cause brain damage or death if not treated quickly