Renal compensation is an attempt by the kidneys to control the overall level of acidity, or pH, of blood serum. If it is too acidic or alkaline, the patient can develop health problems that will create a series of cascading reactions in the body. The kidneys are one of the lines of defense used to address acidosis or alkalosis. It can take several days for the renal compensation to kick in and stabilize the pH and the kidneys may not be able to maintain the desired value if the underlying cause of the problem is not addressed.
The metabolism and respiratory tract are involved in regulating internal pH through exchanging chemicals, excreting excess, and making sure the cells get the oxygen and nutrients they need. People can develop pH imbalances as a result of metabolic disorders or breathing problems, like severe asthma that limits respiration. When the cells detect an imbalance, they respond by releasing chemicals to stabilize the body. If this is not successful, renal compensation may occur.
Structures in the kidneys can determine if the blood is too alkaline or acidic, and decide which compounds to retain and which to excrete on this basis. They can change their absorption level of bicarbonate, for example, to control the level of acidity. Over the course of several days, the kidneys are able to filter the blood and restore balance. Tests performed during renal compensation can show the effects of these efforts and also provide information about overall kidney function.
In cases where a patient has alkalosis or acidosis caused by an underlying medical problem, renal compensation may not be enough. The patient can develop a chronic pH imbalance that the kidneys are unable to regulate effectively. Treatment is needed to address the cause and eliminate the imbalance at the source; a patient with respiratory problems, for example, might need to use inhalers to dilate the airways, or could require supplementary oxygen to facilitate gas exchange in the lungs.
Blood testing can reveal if the serum pH is off, and also provides information about how the body is responding. Signs of renal compensation can be seen in the presence of various chemicals in the blood. If the patient’s kidneys start to fail, they will no longer be able to compensate, and the pH imbalance may get much worse without intervention. Dialysis may be used as one measure to filter the blood, but it is not as efficient as real kidneys.