Utstein - animal studies and lab reporting

Question 1

Define baseline conditions

Answer 1

The physiological conditions attained before induction of cardiac arrest, usually in an anesthetized, intubated, ventilated, and instru- mented animal.

Question 2

Define induction of CA

Answer 2

The method and time of induction of a hemody- namic condition of no blood flow is essential infor- mation and should be depicted graphically on a time line.

Question 3

Define standard chest compressions

Answer 3

External closed chest compressions applied to an area of the chest approxi- mately the size of the heel of an adult’s hand (15 to 25 cm*). The frequency of compressions is usually 60 to 100 per min, with a 50% duty cycle and a downward compression force sufficient to produce 3.8 to 5 cm (1.5 to 2 in) of chest displacement in a large animal.

Question 4

Define CA

Answer 4

In the clinical setting, cardiac arrest is defined as the ‘cessation of cardiac mechanical activity…. It is a clinical diagnosis, confirmed by unresponsiveness, the absence of a detectable pulse and apnoea.

Most laboratory studies produce cardiac arrest by electrically inducing ventricular fibrillation, which can be confirmed by electrocardiography. Blood flow stops quickly, and this can be identified by the sudden loss of arterial pulsations on intravascular pressure monitors and by a systolic aortic blood pressure of < 25 mm Hg

With cardiac arrest secondary to asphyxia or exsanguination, the gradual decline in blood pressure is not usually accompanied by a sudden change in cardiac rhythm or ECG pattern. Regardlessof which technique is used to induce cardiac arrest, it should be defined precisely enough to allow reproduction by other investi- gators

Question 5

Define ventilation

Answer 5

Any movement of gas in and out of the lungs.

Question 6

Define alveolar ventilation

Answer 6

The amount of inspired gas available for gas exchange (minute ventilation minus dead-space ventilation).

Question 7

Define compression phase

Answer 7

Measurements obtained when applied force decreasesthe thoracic votume (analogous to the systolic phase in a beating heart).

Question 8

Define release phase

Answer 8

Measurements made during the CPR cycle when little or no pressure is being applied to the thorax. allowing it to recoil.

Question 9

Define active decompression

Answer 9

When an outward force is ap- plied to the external chest during the release phase.

Question 10

Define coronary perfusion pressure

Answer 10

The simultaneous difference between the aortic and right atria1 (or central venous) pressures during diastole

Question 11

Define ROSC

Answer 11

Maintenance of a systolic aortic blood pressure of at least 60 mm Hg for at least 10 consecutive minutes.

Question 12

Define survival

Answer 12

Existence beyond return of spontaneous circulation and the immediate postarrest period - at least 24 hours.

Question 13

Define non-intervention interval

Answer 13

The interval of un- treated cardiac arrest without chest compression.

Question 14

What are the methods of inducing CA?

Answer 14

• Exsanguination
• Hypoxia
• Asphyxia
• IV wire
• Fibrillatory shock

Question 15

How do you assess cerebral outcome in animal studies?

Answer 15

Cerebral outcome should be measured in terms of brain morphology (with such tools as the histopatho- logic damage score) and function (with such tools as the overall performance and neurological damage scores).

Electroencephalogram patterns of early postarrest recovery in animals are quite consistent but do not correlate well with functional and morphological out- come score