Mechanical Ventilation Indications/Calculations

IBW, mL/kg, indications: pH, CO2, O2 + patient condition

1 foot is how many inches?

12 inches

What is the man and woman IBW equation?

Man (lbs) = 106 + 6 (H-60)

Woman (lbs) = 105 + 5 (H-60)

1 lb = kg?

0.45 kg

1 kg = lb?

2.2 lbs

1 inch = cm?

2.54 cm 

What are 3 main topics to assess to recognize if a patient is in respiratory distress?

1. LOC

2. appearance and texture of skin

3. vital signs

*note: also look at how the patient is breathing

What is acute respiratory failure (ARF) defined as?

1. PaO2 below patients baseline

a. PaO2 is either mild, moderate, or severe

b. PaO2/FiO2 ratio mild, moderate, or severe

2. PaCO2 greater than 50 mmHg and rising

3. pH of 7.25 or lower

What is the normal MIP and MEP?

MIP: -100 to -50 cmH2O

What is the normal VC?

65 to 75 mL/kg

What is the normal FEV1?

50 to 60 mL/kg

What is the normal PEFR?

350 to 600 L/min

What is the PaO2/PAO2 ratio?

reflects the efficiency of oxygen transfer across the alveolar-capillary membrane

*note: normal should be 1.0 to 0.75, the smaller it gets the worse the oxygen transfer it 

What is the P(A-a)O2?

reflects the efficiency of oxygen transfer from alveoli into bloodstream (*note: very similar to PaO2/PAO2

-normal: 5 to 20 mmHg

-increased: 20+ = gas exchange problem

-decreased or normal gradient but hypoxemia: hypoventilation or low inspired O2

What is the PaO2/FiO2 ratio?

it measures how well oxygen in the inspired air is being transferred into arterial blood

-normal: 400+

-mild: 400 to 300

-moderate: 300 to 200

-severe: less than 200

How much tidal volume is lost within an HME?

50 to 100 mL