Acute Respiratory Failure

Question 1

Criteria for Intubation: Mechanics

Answer 1

RR>=35/min

VC <=15 cc/kg for adults, 10 cc/kg for children

NIF<=20 cm H20

Question 2

Criteria for Intubation: Oxygenation

Answer 2

PaO2<=70 on FiO2 40%

A-a gradient >=350 torr with FiO2 100%

Question 3

Criteria for Intubation: Ventilation

Answer 3

PaCo2 >=55 (except in chronic hypercarbia)

Vd/Vt>=0.6 (nl is 0.3)

Question 4

Criteria for extubation

Answer 4

Stable vitals (RR<=30-35/min), no inotropes, afebrile

good grip, sustained head lift

PaO2>=70, PaCo2<55 with FiO2 40%

NIF >=20 cm H2O

VC>=15 cc/kg

Question 5

Weaning from Vent: T-Piece

Answer 5

• T piece adapter and heated nebulizer attached to ETT
• Sit pt up
• FiO2 higher
• Check vitals and sats during first 1-2 hrs
• extubate after 2-4hrs

Question 6

Weaning from vent: IMV technique

Answer 6

IMV gradually decreased until spontaneous ventilation begins

Question 7

PEEP indications

Answer 7

PaO2 <=60 mm Hg with FiO2 >=60%

Question 8

PEEP actions

Answer 8

• increases FRC
• for every 5 cm H2O PEEP, FRC increases 400 cc
• imrpoves relationship between FRC and closing capacity, decreasing intrapulmonary shunting
• decreases CO by increasing intrathoracic pressure and decreasing venous return
• best peep is when O2 transport (CO, O2 content) are optimized

Question 9

Treatment of hypotension with PEEP

Answer 9

• optimize volume status
• inotrope such as dopamine

Question 10

Fat embolism: setting

Answer 10

hip/pelvic/long bone fractures with periop hypoxemia

10-15% chance of high morbidity and mortality

Question 11

Fat embolism syndrome: CV

Answer 11

Tachycardia/hypotension

EKG: myocardial ischemia and right heart strain

Question 12

Fat embolism syndrome: Respiratory

Answer 12

• increased Vd/Vt leads to moderate to severe hypoxemia
• PaO2 decreases, PaCo2 rises

Question 13

Fat embolism syndrome: CNS

Answer 13

confusion, botundation, coma

Question 14

Fat embolism syndrome: Blood

Answer 14

• rise in serum lipids, free fatty acids, triglycerids
• decreased hematocrit (erythrocyte aggregation)
• thrombocytopenia (increase platelet aggregation)
• increase fibrin degradation products
• prolonged PT/PTT

Question 15

Fat embolism syndrome:skin

Answer 15

petechiae on anterior chest, axilla, neck, conjunctiva in 50% of cases