pH
pH measures the hydrogen concentration of blood. A Sanz electrode with pH sensitive glass is used to measure change in hydrogen ion concentration. Pleural fluid, cord blood, and fetal scalp blood can also be analyzed.
Reference range for blood is 7.35 - 7.45. Acidemia is present if the pH is less than 7.35 and alkalemia is present if pH is greater than 7.45. The presence of a normal pH does not rule out an acid-base disturbance. Reference range for urine is 4.5 - 8.0.
Specimen requirement is one lithium heparin blood gas syringe of blood, 1 mL of body fluid in a red top tube, or 1 mL of random urine in a specimen cup.
