Emergency Medical Technician (EMT) Intermediate Practice Exam

Which equation represents metabolic acidosis?

1. ↓ H2CO3 → ↑ H+ + HCO3- → ↑ pH

2. ↑ H2CO3 → ↑ H+ + HCO3- → ↓ pH

3. H2CO3 + O2 → HCO3- + CO2

4. H+ + HCO3- → H2CO3 → H2O + CO2

The correct answer is: ↑ H2CO3 → ↑ H+ + HCO3- → ↓ pH

Metabolic acidosis is characterized by an increase in hydrogen ions (H+) in the body, leading to a decrease in pH, which indicates acidity. When the equation encompasses an increase in carbonic acid (H2CO3), this suggests that more hydrogen ions are being released into the solution. In this context, the reaction shows that as carbonic acid increases, it dissociates into hydrogen ions and bicarbonate (HCO3-). The presence of more hydrogen ions results in a lower pH, which is emblematic of acidosis, as the blood becomes more acidic. Thus, the equation accurately describes the physiological changes occurring during metabolic acidosis, highlighting the causative relationship between increased acidity and decreased pH. This underscores the importance of monitoring acid-base balance in patients and the implications it has on their overall metabolic state. Understanding the chemical processes involved, like the dissociation of carbonic acid, is crucial in the identification and management of metabolic acidosis in a clinical setting.