ICU (PGY3)

Question 1

Definition of ARDS

Answer 1

Acute Respiratory Distress Syndrome: acute diffuse inflammatory lung injury resulting in increased pulmonary vascular permeability, increased lung weight, loss of aerated lung tissue with hypoxemia

Question 2

Berlin Criteria for ARDS

Answer 2

1. Acute - within 1 week of insult; 2. B/l GGO infiltrates; 3. Findings not explained by cardiogenic pulmonary edema; 4. PaO2/FiO2 of < 300

Question 3

Normal PaO2

Answer 3

75- 100 mmHg

Question 4

Categories of ARDS (based on PaO2/FiO2)

Answer 4

Mild: 200- 300
Moderate: 100-200
Severe: < 100

Question 5

(3) phases of lung injury in ARDS

Answer 5

1. exudative phase: immune cell mediated, proinflammatory
2. proliferative phase: reabsorption of alveolar edema to restore normal alveolar architecture/function; 3. fibrotic phase: final phase

Question 6

Causes of ARDS (2) categories

Answer 6

1. Direct Lung Injury - infection, inhalational injury, toxins, drowning, high altitude sickness, burns, trauma, aspiration; 2. Indirect Lung Injury - sepsis, pancreatitis, drug OD, transfusion related (TRALI), DIC

Question 7

MGMT of ARDS

Answer 7

supportive to LIMIT FURTHER INJURY - treat underlying cause (i.e., PNA). lung protective ventilation settings

Question 8

Definition of lung protective ventilation settings (i.e., ARDS)

Answer 8

1. Low Tidal volumes (VT 6 cc/kg) of IDEAL WEIGHT; 2. permissive hypercapnea (due to low tidal volumes) allow for pCo2 of 60-70 (normally 40); 3. Plateau pressures < 30 (to avoid VILI); 4. Recruitment to improve oxygenation (PEEP 30-40 heldd 30 seconds); 5. Consider proning in severe cases (PaO2/FiO2 < 150)

Question 9

Definition of DIC

Answer 9

acquired coagulation syndrome resulting in excessive clotting and clotting factor consumption with subsequent bleeding in severely ill patients

Question 10

Mechanism of DIC

Answer 10

coagulation cascade is activated and control mechanism are lost -
thrombin clots into capillaries and small vessels; as a result excessive clotting consumes the body’s store of clotthing factors and plts, clot deposition in microcirculation leads to hemolysis as RBC try to pass through, counter-regulatory system (the fibrinolytic system) gets activated and starts dissolving clots

Question 11

Causes of DIC

Answer 11

bleeding/trauma, pregnancy (placental abruption, IUFD, amniotic fluid embolus, HELLP syndrome), ARDS, acute liver failure, pancreatitis, amlignancy, vasculitis, venom snake, transfusion reactions

Question 12

Clinical Presentation of DIC

Answer 12

hypercoagulation, hyperfibrinolysis, mixed picture; end organ failure or gangrene in small vascular beds like fingers and toes - most common presentation in septic DIC patients; oozing from IV sites or sites of trauma

Question 13

Lab values in DIC

Answer 13

low plts, high INR, low fibrinogen (used to make fibrin clots), high D-dimer, high PTT, high clotting time, low factor 2,5,7,10)

Question 14

MGMT of DIC

Answer 14

treat underlying cause, fix lab abnormaliites - pRBC, plts, FFP, Vitamin K (INR > 1.5 or fibrinogen < 100)

Question 15

FFP dosing

Answer 15

15 cc/kg

Question 16

Dose of osmotic agents in ICP

Answer 16

3% NS 250 cc over 10-15 mins; Mannitol 1g/kg over 10 mins; NaBicarb 1-2 amps slow IV push over 10 mins

Question 17

EtCO2 target for high ICP (herniating)

Answer 17

PaCO2 of 35-39 mmHg; PaCO2 < 25 can cause profound cerebral vasoconstriction which can worsen hypoperfusion

Question 18

normal ICP range

Answer 18

5- 15 mmHg; mild intracranial HTN is 20 - 30 mmHg;

Question 19

TTP Mnemonic - “FAT RN”

Answer 19

fever, anemia (MAHA), thrombocytopenia (with purpura), renal sx, neuro sx

Question 20

HUS vs. TTP

Answer 20

TTP has more NEURO/CNS involvement vs. HUS has more renal involvement. HUS is usually incontext of diarrhea

Question 21

ITP vs. TTP

Answer 21

ITP pts are generally well appearing with normal RBC.

Question 22

DIC vs. TTP

Answer 22

DIC pts have multiple sites of bleeding, elevated INR/PTT and D-dimer vs. TTP pts do not bleed overtly, and have normal to mildly elevated INR/PTT, D-dimer

Question 23

TTP MGMT

Answer 23

plasma exchange if MAHA present (schistocytes, elevated LDH, elevated INDIRECT hyperbilirubinemia)