Question

If a shock is not��� indicated, how many cycles of CPR will you give before analyzing��� again?

A. 10
B. 15
C. 2
D. 5

Answer 1

The correct answer to the CPR cycle question is C. 2, as two cycles of CPR should be performed before re-analyzing the patient's heart rhythm in cases where a shock is not indicated. The detailed answer also includes calculations for various parameters associated with the use of a defibrillator during surgery.

Step-by-step explanation:

Answer to CPR Cycles Before Analysis

If a shock is not indicated during the administration of CPR (cardiopulmonary resuscitation), it is typically recommended to perform two cycles of CPR before pausing to re-analyze the patient's heart rhythm. Thus, the correct answer to the question is:

C. 2

Calculations for Defibrillator Use During Surgery

Now to the physics questions related to a defibrillator:

1. How much charge passed?
   Charge (Q) is calculated by the formula Q = Current (I) × Time (T).
   For 10.0 A passing through for 5.00 ms (which is 0.005 seconds), the charge is Q = 10.0 A × 0.005 s = 0.05 C (Coulombs).
2. Defibrillator's applied voltage with 500 J energy dissipation:
   Using the energy (W) formula, W = V × Q, and rearranging this for voltage (V), we get V = W / Q.
   If 500 J of energy is dissipated, then the voltage applied is V = 500 J / 0.05 C = 10,000 V (Volts).
3. Path's resistance calculation:
   Using Ohm's Law, V = I R, where R is resistance.
   With the given energy (W = 500 J) and charge (Q = 0.05 C), we first find the voltage (we calculated it as 10,000 V in the previous step), and then we can calculate resistance by R = V / I = 10,000 V / 10.0 A = 1,000 Ω (Ohms).
4. Temperature increase in tissue:
   Using the formula for specific heat capacity (c), Q = c m ΔT, and rearranging to find the increase in temperature (ΔT), we have ΔT = Q / (c m).
   Assuming the specific heat capacity of human tissue is approximately 3470 J/(kg°C), and with 8.00 kg of tissue and 500 J of energy:
   ΔT = 500 J / (3470 J/(kg°C) × 8.00 kg) = 0.018°C temperature increase.

For the open-heart surgery and defibrillator voltage required:

The voltage (V) needed for a 10.0-mA (0.010 A) current through a resistance (R) of 500 Ω is calculated using Ohm's Law, V = I R.
So the required voltage is V = 0.010 A × 500 Ω = 5 V (Volts).