Anonymous asked in Science & MathematicsChemistry · 1 decade ago

Please please please please pleaseee helpppp?

Cardiac arrest occurs when the heart stops and blood circulation is halted, but cellular reactions continue. When this occurs, doctors often inject sodium bicarbonate solution, NaHCO3, which contains the base HCO3, directly into the heart muscle even before restarting the heart.

a) what effect would cardiac arrest have on blood pH? why?

b) how would the injection counteract this effect?

6 Answers

  • 1 decade ago
    Favorite Answer

    ok. let's see. when the heart stops, there is no blood flowing. that means that there is also no blood flowing to the lungs. hence, oxygen does not bind to the red blood cells. since cellular respiration uses up the oxygen and produces carbon dioxide, the CO2 will react with water to form carbonic acid. Carbonic acid(H2CO3). carbonic acid then dissociates to form H+ ions and also HCO3- ions. since the conc of H+ increases, thus the pH reduces causing the blood to become more acidic. by adding HCO3, it increases the conc of HCO3 in the blood. Since this reaction is a reversible reaction, according to Le Chatelier's principle, the equilibrium will shift to a direction that minimises the changes directed to a system. in this case it means forming more carbonic acid will reduce the conc of the HCO3 added. therefore, HCO3 binds with the H+ ions to form the carbonic acid. H+ conc reduces and ph returns to normal.

    hope i helped. Good Luck !!!

    oh ya i forgot, NaHCO3 fully dissociates to form HCO3 and Na+. hope this completes my answer.

  • 1 decade ago

    well if HCO3 is basic, then the effects of cardiac arrest must be acidic, otherwise it wouldn't be used to neutralize the pH, right? (or am I totally reading this incorrectly?)...

    I would say that the injection would neutralize the acidification of the blood.

    Ok...let me think this through. Cellular reactions means cellular respiration? Cellular respiration produces CO2 which is acidic, so if the heart isn't pumping O2 into the blood stream (which is gets from the lungs), then the blood would turn acidic, right?

    So, by injecting the HCO3, the blood pH will be neutralized. It has something to do with NaHCO3 + CO2...but I don't know that reaction.

    This may have helped?

  • 1 decade ago

    First: I am niot a medical qualified person.

    Second: U dont have to believe a single word I say here.

    Third: I believe during a cardiac arrest the pH of the blood must have dropped considerably to an 'acidic level'. This could be due to, in many cases, the victim had been in a satate of physical strain creating the acidic medium in the blood stream.

    The doctor inject NaHCO3 to balance the electrolytes i.e. to neutralize the acidity and bring the blood back to a more acceptable pH........... and follow up to jump-start the heart again.'s my guess. U may want to believe not not believe I think I am talking out of my depth.....but I hope its not just all Bull!


  • 1 decade ago

    Cellular respiration would continue and the carbon dioxide would begin to saturate the blood making the blood more acidic. NaHCO3 may act as a type of buffer.

  • How do you think about the answers? You can sign in to vote the answer.
  • lcmcpa
    Lv 7
    1 decade ago

    You must be a nursing or med student. Don't have others do your homework. You might need to know this someday to help save a person's life.

  • 1 decade ago

    Find a cardiologist and ask her.

Still have questions? Get your answers by asking now.