Updated: 12/28/2020

Acute Respiratory Distress Syndrome (ARDS)

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
6 6
0
0
0%
0%
Evidence
4 4
0
0
0%
0%
Videos
2 2
Snapshot
  • A 46-year-old woman is admitted to the ICU with severe pancreatitis. During the first 24 hours of admission, severe hypoxemia that requires ventilatory support with high concentrations of inspired oxygen develop. On exam the patient has rhonchi and crackles bilaterally. An arterial blood gas collected at 60% FiO2 reveals pH 7.42, PCO2 35 mmHg, and PO2 108 mmHg.
Introduction
  • Defined as acute diffuse, inflammatory lung injury leading to increased vascular permeability, increased lung weight and loss of aerated lung tissue   
    • hyperactivation of coagulation and/or inflammation damages both type I and II pneumocytes
      • ↓ type II pneumocytes results in ↓ surfactant production
      • ↓ surfactant production results in low lung compliance and subsequent atelectasis
    • repair often results in interstitial fibrosis
  • Causes
    • infection
      • pneumonia
      • sepsis
        • typically gram-negative sepsis
    • aspiration
    • acute pancreatitis
    • trauma with shock
    • amniotic fluid embolism (rare)
    • uremia
Presentation
  • Symptoms
    • dyspnea
  • Physical exam
    • tachypnea
    • bilateral rales and decreased breath sounds
Evaluation
  • Arterial blood gas
    • severe hypoxemia on pulse oximetry and ABG
      • may not be responsive to 100% O2
      • atelectasis results in intrapulmonary shunting
  • Radiology
    • diffuse, bilateral alveolar infiltrates on CXR
    • ground glass opacities and consolidations on chest CT often with dependent lung predominence
  • Histology 
    • diffuse alveolar damage
    • protein-rich leakage (exudate) forming an intra-alveolar hyaline membrane 
  • Severity graded on PaO2 / FiO2 ratio and required PEEP (see below)
Treatment
  • Respiratory support & treat underlying cause
    • Mechanical ventilation with low tidal volume (4-6 mL/kg ideal body weight) 
    • High FiO2
    • PEEP (positive end-expiratory pressure)
      • prevents airway collapse at end-expiration
      • recruits collapsed alveoli
        • increases FRC and decreases shunting
      • improves oxygenation 
 

Please rate topic.

Average 4.8 of 10 Ratings

Questions (6)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M1.PL.15.96) A 48-year-old female suffers a traumatic brain injury while skiing in a remote area. Upon her arrival to the ER, she is severely hypoxemic and not responsive to O2 therapy. She is started on a mechanical ventilator and 2 days later upon auscultation, you note late inspiratory crackles. Which of the following is most likely normal in this patient? Tested Concept

QID: 100899
1

Type I pneumocytes

9%

(4/47)

2

Type II pneumocytes

28%

(13/47)

3

Chest X-ray

0%

(0/47)

4

Alveolar-arterial gradient

13%

(6/47)

5

Left atrial pressure

49%

(23/47)

M 2 D

Select Answer to see Preferred Response

(M1.PL.14.23) A 45-year-old man arrives by ambulance to the emergency room after being involved in a very severe construction accident. The patient was found unconscious with a large metal spike protruding from his abdomen by a coworker who was unable to estimate the amount of time the patient went without medical aid. Upon arrival to the ER, the patient was unconscious and unresponsive. His vital signs are BP: 80/40, HR: 120 bpm, RR: 25 bpm, Temperature: 97.1 degrees, and SPO2: 99%.He is taken to the operating room to remove the foreign body and control the bleeding. Although both objectives were accomplished, the patient had an acute drop in his blood pressure during the surgery at which time ST elevations were noted in multiple leads. This resolved with adequate fluid resuscitation and numerous blood transfusions. The patient remained sedated after surgery and continued to have relatively stable vital signs until his third day in the intensive care unit, when he experiences an oxygen desaturation of 85% despite being on a respirator with 100% oxygen at 15 breaths/minute. On auscultation air entry is present bilaterally with the presence of crackles. A 2/6 systolic murmur is heard. Readings from a Swan-Ganz catheter display the following: central venous pressure (CVP): 4 mmHg, right ventricular pressure (RVP) 20/5 mmHg, pulmonary artery pressure (PAP): 20/5 mmHg. Pulmonary capillary wedge pressure (PCWP): 5 mm Hg. A chest x-ray is shown as Image A. The patient dies soon after this episode. What is the most likely direct cause of his death? Tested Concept

QID: 104029
FIGURES:
1

Diffuse alveolar damage

72%

(33/46)

2

Ventricular septal defect

0%

(0/46)

3

Myocardial free wall rupture

9%

(4/46)

4

Papillary muscle rupture

15%

(7/46)

5

Myocardial reinfarction

2%

(1/46)

M 2 D

Select Answer to see Preferred Response

(M1.PL.13.112) A 58-year-old male is hospitalized after sustaining multiple fractures in a severe automobile accident. Soon after hospitalization, he develops respiratory distress with crackles present bilaterally on physical examination. The patient does not respond to mechanical ventilation and 100% oxygen and quickly dies due to respiratory insufficiency. Autopsy reveals heavy, red lungs and histology is shown in Image A. Which of the following is most likely to have been present in this patient shortly before death: Tested Concept

QID: 100915
FIGURES:
1

Diaphragmatic hypertrophy

0%

(0/63)

2

Proliferation of bronchiolar mucous glands

3%

(2/63)

3

Interstitial edema

52%

(33/63)

4

Large pulmonary embolus

41%

(26/63)

5

Left apical bronchoalveolar carcinoma

0%

(0/63)

M 2 E

Select Answer to see Preferred Response

Evidence (5)
VIDEOS (2)
Topic COMMENTS (18)
Private Note