Acidosis is known to affect several physiological processes negatively. It can inhibit enzymatic reactions crucial for cellular metabolism, shift the oxyhemoglobin dissociation curve (the Bohr effect), and worsen cardiovascular performance by depressing myocardial contractility, blunting the response to catecholamines, and altering vascular tone. Based on these effects, it has been logically inferred that correcting acidosis, such as through the administration of bicarb, would mitigate these negative effects and improve patient outcomes.
However, the relationship between blood pH levels and clinical outcomes is complex. While severe acidosis is undoubtedly associated with critical illness and can indicate poor prognosis, the causal relationship between pH correction and improved outcomes is not as direct as previously assumed. For instance, the body's compensatory mechanisms to acidosis, including changes in respiratory rate and kidney function, aim to balance pH, suggesting that the body can tolerate a certain degree of pH variation without immediate, dire consequences.
Emerging evidence challenges the straightforward approach of using bicarb to correct acidosis for several reasons, which will be covered in the next sections.
