Buffer agents do not reverse intramyocardial acidosis during cardiac resuscitation

Area of Science:

• Cardiology
• Biochemistry
• Critical Care Medicine

Background:

• Acidosis is a common complication during cardiac arrest.
• Buffer agents are often used to manage acidosis during resuscitation.
• The efficacy of different buffer types on myocardial pH and resuscitability remains debated.

Purpose of the Study:

• To investigate the effects of carbon dioxide-producing and carbon dioxide-consuming buffers on intramyocardial pH.
• To assess the impact of these buffers on cardiac resuscitability during experimental cardiac arrest.

Main Methods:

• Intramyocardial pH was continuously measured in pigs using a glass electrode.
• Ventricular fibrillation (VF) was induced, followed by 8 minutes of precordial compression.
• Sodium bicarbonate, Carbicarb, or saline was infused during resuscitation, with defibrillation attempted after 11 minutes of VF.

Main Results:

• Intramyocardial pH decreased significantly during cardiac arrest, despite buffer administration.
• Systemic and great cardiac vein pH increased with buffer agents, but intramyocardial pH continued to decline.
• Neither buffer solution altered myocardial acidosis or improved resuscitability; outcomes correlated with coronary perfusion pressure.

Conclusions:

• The administration of carbon dioxide-producing or consuming buffers does not improve myocardial acidosis during cardiac arrest.
• Buffer agents do not enhance cardiac resuscitability in this experimental model.
• Coronary perfusion pressure, not pH, is the critical factor for successful defibrillation.