Pretest Critical Care ch 2

Question 1

Tx for patient bleeding from tracheostomy?

Answer 1

Tracheoinnominate artery fistula:
Ongoing bleeding - compress the innominate artery: inflation of the tracheotomy balloon, placement of a finger into tracheostomy to compress artery, or reintubation of patient with endotracheal tube.
Not bleeding - immediate fiberoptic exploration in the OR

Question 2

Parameters for extubation?

Answer 2

Rapid shallow breathing index (RespRate:TV): 60-105
Negative inspiratory force: -20+cm H2O
Weened to 5cm H2O PEEP
Minute ventilation (RRxTV); 10-L/min
Spontaneous respiratory rate: 20- breaths/min

Question 3

Immediate tx for hemolytic transfusion reaction?

Answer 3

Stop transfusion
insert foley catheter (confirmation and monitoring)
Diuresis with mannitol
Alkalization with sodium bicarb to prevent precipitation of hemoglobin in the kidney

Question 4

Contraindications of nitrous oxide?

Answer 4

SBO surgery.

NO diffuses into air more readily than any other anesthetic gas, and may lead to further distention.

Question 5

Dx of ARDS?

Answer 5

Bilateral pulmonary infiltrates on CXR
PaO2:FiO2 less than 200
Pulmonary wedge pressure less than 18mmHg

Question 6

Affect of banked blood on O2 dissociation?

Answer 6

Causes left shift of curve, decreasing O2 uptake by tissues. Caused by low levels of 2,3-DPG in banked blood cells. Overcome with increased PaCO2, inc temperatures, and acidosis.

Question 7

Definition and tx for: TRALI, transfusion allergic rxn, TACO, hemolytic rxn?

Answer 7

TRALI: Transfusion related acute lung injury; Tx stop transfusion and ventilatory support.
Allergic: rash and fever; Tx antihistamine
TACO: Transfusion associated circulation overload, occurs in pts with heart failure who receive large transfusions; Tx Diuretics

Question 8

Difference in cardiac actions between nitroglycerin and dobutamine?

Answer 8

Nitroglycerin causes vasodilation and decreased preload and after load on the heart, but has no inotropic effects.
Dobutamine is a B1 agonist = peripheral vasodilation AND positive inotropy. A synthetic catecholamine, best choice for cardiogenic shock since the heart pumps harder against less resistance.

Question 9

Actions of dopamine

Answer 9

All doses: diastolic BP rises = inc coronary perfusion
Low doses: Dopaminergic receptors, vasodilates renal and mesenteric, vasoconstricts peripheral, no SVR change
Med doses: B1 agonist, inc inotropy inc CO and BP
High doses: a-agonist, peripheral and renal vasoconstriction, inc organ perfusion, hypertension

Question 10

What does pulmonary artery monitoring provide physicians?

Answer 10

Allows physicians to monitor volume status and heart function. Useful to assess whether a patient needs increased fluids or inotropic medications.

Question 11

What does an arterial catheter allow physicians to monitor?

Answer 11

An arterial catheter provides beat-to-beat monitoring of the patient’s blood pressure. Useful in cases that require aggressive blood pressure monitoring (think post-op hemorrhagic stroke, nitroprusside or nitroglycerine infusions).

Question 12

Components of the extrinsic pathway and their names?

Answer 12

Factor I (fibrinogen)
Factor II (prothrombin)
Factor V
Factor VII
Factor X

Question 13

What does TT measure?

Answer 13

Thrombin Time

Measures qualitative abnormalities in fibrinogen (Factor I) and the presence of inhibitors to fibrin polymerization.

Question 14

What innervates the intrinsic muscles of the hand?

Answer 14

The ulnar nerve innervates 15 out of the 20 intrinsic muscles.

Question 15

What are the preferred margins for excising melanomas?

Answer 15

Depends on the depth of the lesion:
Less than 1mm = 1 cm
1-4 mm = 2 cm
greater than 4 mm = 3 cm

Question 16

Describe the sequence of events in skin wound healing?

Answer 16

1 - Neutrophils invade
2 - Macrophages arrive on day 2, phagocytose bacteria and debris, produce TNF, tissue growth factor, platelet derived growth factor, fibroblast growth factor (Proliferative phase, angiogenesis and collagen formation)
3 - Fibroblasts arrive around day 3, continue proliferative phase with type 3 collage for 2-3 weeks
4 - remodeling phase begins after 2-3 weeks, type 3 elastic collagen is replaced with type 1 rigid collagen

Question 17

What are the four wound classes and their definitions?

Answer 17

Class I, clean wound, surgeries in which no part of the respiratory, gastrointestinal, or genitourinary tracts are entered. Herniorrhaphy and breast surgeries.

Class II, clean-contaminated, surgeries that involve entering those organ systems, but without active infection or gross spillage. Elective lap-chole or bowel resection with prep.

Class III, contaminated, open accidental wounds soon after injury, introduce bacteria into sterile areas, or result in gross spillage of viscus contents. Penetrating abdominal trauma, large tissue injury, etc.

Class IV, dirty, traumatic wounds with significant delay to treatment, presence of necrotic tissue, perforated viscus with high degree of contamination. Perforated diverticulitis, necrotizing soft tissue infections.

Question 18

What are Marjolin ulcers, erythroplasia of Queyrat, and what are they associated with?

Answer 18

Marjolin ulcer: thermal injury that results in SCC

Erythroplasia of Queyrat: SCC tumor specific to the penis

Question 19

Most common malignant tumor found on the lips?

Answer 19

SCC

Question 20

Side effects of silver nitrate?

Answer 20

Silver nitrate:
Electrolyte disturbances (hyponatremia, hypokalemia, hypocalcemia, hypochloremia)
Methemoglobinemia

Nitrate = natremia??

Question 21

Describe primary, secondary and tertiary intention in wound healing.

Answer 21

Primary - standard surgical closure in which the edges of the wound are brought together and sutured back to each other.

Secondary - The wound is left open and allowed to heal from the inside up by epithelialization. Useful in draining abscesses and highly contaminated wounds.

Tertiary - A wound that is treated with repeated therapy (multiple debridements, antibiotics, negative pressure dressing, etc) and kept from healing until the infection is controlled, then closed by suturing, graft, or skin flap. Effectively a delayed primary intention.

Question 22

Describe the types of skin grafts

Answer 22

Composite tissue graft -

Question 23

Most common organism in nosocomial bacteremia?

Answer 23

Coagulase-negative Staphylococcus

Question 24

What sorts of wounds should be left open?

Answer 24

Dirty, contaminated (animal bites), trauma (gunshot, puncture, crush), or that are more than 6 hours old.
Prophylactic Antibiotic therapy has not been shown to prevent wound infections.