Acute Respiratory Failure & ARDS

Question 1

when oxygenation, ventilation, or both are inadequate

Answer 1

Acute respiratory failure

Question 2

Impaired gas exchange

Answer 2

Hypoxemic respiratory failure (failure of
oxygenation)

Question 3

Impaired ventilation

Answer 3

Hypercapnic respiratory failure (failure of
ventilation)

Question 4

Combined failures (failures of oxygenation & ventilation)

Answer 4

Hypoxemic and Hypercapnic

Question 5

Oxygenation failure
PaO2 <= 60 mmHg on >= 60% oxygen

Answer 5

hypoxemic

Question 6

Ventilatory Failure
PaCO2 > 50mmHg and pH <7.35

Answer 6

hypercapnic

Question 7

Ph: 7.37
PacO2: 60
Pao2: 85
Hco3: 24

hypoxemia or hypercapnic

Answer 7

hypercapnic

Question 8

Ph: 7.35
PacO2: 55
Pao2: 40
Hco3: 24

Hypoxemia or hypercapnic

Answer 8

Both/ hypercapnic and hypoxic

Question 9

Hypercapnic clinical manifestations. Early signs

Answer 9

1. Sudden or gradual onset
2. Change in mental status – first sign resp failure
3. Early signs – tachycardia, tachypnea, mild hypertension
4. Dyspnea
5. Other respiratory findings: prolonged expiration, nasal flaring,
   retractions, use accessory muscles, SpO2 <80%
6. Skin cool/clammy, diaphoretic
7. Anxiety
8. Fatigue, inability to speak in complete sentences without pausing to
   Breathe
9. Decreasing LOC - Lethargy

Question 10

Hypercapnic clinical manifestations late signs

Answer 10

hypotension, dysrhythmias, cyanosis ( PaO2 45 mmHg or less), paradoxical breathing or abdominal wall movement, coma

Question 11

How to diagnosis hypercapnic respiratory failure

Answer 11

(1) Chest xray
(2) ABGs
(3) Oxygen saturation
(4) CBC, BMP, urinalysis
(5) Sputum, blood cultures
(6) CT or V/Q (specific to perfusion, can spot PE so can CT) lung scan

Question 12

If a person has unilateral lung disease how do you lay them?

Answer 12

position the good lung down. Them laying on the side of the good lung

Question 13

Acute onset (less than 7 days) of refractory hypoxemia and bilateral infiltrates

Answer 13

Adult respiratory distress syndrome (ARDS)

Question 14

How is ARDS caused

Answer 14

1. Caused by direct or indirect injury to lungs – Sepsis most common
2. Direct injury
   a) Aspiration, pneumonia, sepsis
   b) Other causes: chest trauma, embolism,
   inhalation injury, near-drowning, O2 toxicity
3. Indirect injury
   a) Sepsis, massive trauma, severe TBI, shock
   b) Other: pancreatitis, cardiopulmonary bypass, DIC, opioid
   overdose, multiple blood transfusions (TRALI)

Question 15

ARDS Criteria

Answer 15

1. Refractory hypoxemia (intubated pt, p/f ratio less than 300, Fi02 of 100% SpO2 of 88) <- example
2. P/F ratio < 300 mmHg
3. Bilateral infiltrates on chest x-ray

Question 16

Ards Severity:
PaO2/FiO2 of 200-300

Answer 16

Mild

Question 17

Ards Severity:
PaO2/FiO2 of 100-200

Answer 17

Moderate

Question 18

Ards Severity:
PaO2/FiO2 of < 100

Answer 18

Severe

Question 19

Diagnosis of ARDS

Answer 19

a) Chest x-ray - Serial
b) ABGs
c) Laboratory testing – CBC, CMP, coagulation studies,
liver and renal function tests, serum lactate (of anaerobic metabolism)
d) Sputum, blood, urine cultures
e) pulmonary function studies

Question 20

Management for ARDS

Answer 20

d) Identify and treat underlying cause
e) Oxygen administration
Correct hypoxemia – high-flow O2 delivery, BiPAP
f) Mechanical ventilation – Goal – SaO2 > 90% with FiO2 < 60%
(1) Pressure A/C
(2) Low tidal volume ventilation (4-6 mL/kg) predicted body
weight
(3) Permissive hypercapnia (PaCO2 60 acceptable (not used TBI or increased ICP)
(4) PEEP
g) Prone Positioning
(1) Recruit collapsed alveoli in posterior part lungs,
helps mobilize secretions
(2) Dependent areas of lungs are more heavily damaged
than nondependent areas
Adequate hydration (IV fluids - crystalloids, colloids)
(1) Adequate blood volume to maintain organ perfusion
(2) Avoid thick, dry secretion, mucous plugs
l) Improve O2 carrying capacity of blood
(1) Administer packed RBCs (keep Hgb 7g/dL)
m) Nutrition
(1) Enteral or parenteral feedings – initiate in 48 – 72 hours of
initiation of mechanical ventilation