Ventilators

Question 1

tidal volume

Answer 1

• amount of air that goes into lungs
• normal = 10 ml/kg –> approx 400 mL
• lung compliance = ease w/which lungs can stretch w/o damage

Question 2

minute volume/minute ventilation (VE)

Answer 2

• volume of air moved thru lungs over 1 min

VT x rate of patient respirations
Normal = 5-10 L
<5 = hypoventilation;
>10 = hyperventilation

ex. VT = 400 cc (=0.4L), pt. RR 8 breaths
0. 4 L x 8 breaths = 3.2 (hypo)

Question 3

vital capacity (VC)

Answer 3

maximum amount of air exhaled after a maximum inspiration
normal = 65 cc/kg

check this before extubation – shows diaphragm function

Question 4

Peak Inspiratory Pressure (PIP)

Answer 4

• pressure that’s in the lung at PEAK OF INSPIRATION (taking a deep breath)
• want it <35
• in 50+ pressures = volutrauma
• high pressure needed for stiff lungs

Question 5

Positive End Expiratory Pressure (PEEP)

Answer 5

• pressure in the lungs at the END OF EXPIRATION (keeps alveoli open)
• mod PEEP = 5-10 cm H2O
  The higher the PEEP, the sicker they are

Question 6

When is someone ventilated?

Answer 6

1. 50/50 rule = PaO2 < 50 mmHg and PaCO2 >50 mmHg

2. RR >35-45

Question 7

assist control

Answer 7

critically ill pt
- set: VT, RR, FiO2, and/or PEEP

• all breaths are delivered by ventilator at set amounts - can weaken resp. muscles (if on long term)

Question 8

synchronized intermittent mandatory ventilation (SIMV)

Answer 8

short term; weaning mode; post op
set: VT, rate, FiO2 and PEEP

If patient breathes below set rate (minimum), vent delivers breaths at set VT, rate, FiO2 and/or PEEP
- Less risk of hyperventilating/barotrauma

Question 9

pressure support ventilation (PSV)

Answer 9

no set VT or rate
patient initiates breath
delivers air to preset pressure (only on inspiration) –> “pressure boost”

Question 10

volutrauma/barotrauma - s/s

Answer 10

over distention and rupture of alveoli

• extreme dyspnea
• absent breath sounds on affected side
• subcutaneous emphysema (crackling under skin)
• decreased BP
• decreased HR

Question 11

GI complications - pts on vents

Answer 11

• distention
• ileus (gastroparesis)
• stress ulcers
• OG or NG suction
• admin meds: H2 antagonists, PPIs, Reglan

Question 12

cardiac complications - pts on vents

Answer 12

vent w/high PEEP increases intrathoracic pressure –> decreases venous return to R heart –> decreases preload –> decreases CO –> hypotension

reduced perfusion to liver, CNS
increased ICP

Question 13

propofol (Diprivan) - effects

Answer 13

rapid onset - ~30 sec
short duration - 3-5 min
begin: 5 mcg/kg/min - up 5-10 mcg, Q 5-1- min

high lipid content - change tubing Q24H
risk of fat overload (blood lipid panel)
profound bradycardia

Question 14

nutritional support of vent patients

Answer 14

enteral route preferred
long term mech vent pt - 2000-2500 kcal/day
monitor labs: pre-albumin, BUN, K+, Ca2+, Mg+, Phos
Interventions: Pulmocare, REspalor; elevate HOB
Flush w/STERILE water after meds
Avoid: opioids

Question 15

NI for vent care

Answer 15

• Change ETT tape/tie Q24H
• inspect skin/oral mucosa
• Move ETT to other side of mouth
• Auscultate breath sounds before and after procedures