If the urinary anion gap is positive or a small negative value in the setting of an acidosis, the kidney is not appropriately producing NH4+, indicating that the kidney is contributing to the acidosis.

• 如果酸中毒时，尿液阳离子间隙是正值或负值很小，那么肾脏就不能正常产生NH4+，表明肾脏参与了酸中毒的产生。