Final answer:
The lab results show a pH of 7.28, PaCO2 of 28 mm Hg, and HCO3- of 18 mEq/L, indicating compensated metabolic acidosis, where the respiratory system tries to correct the acidotic state by lowering the carbon dioxide level.
Step-by-step explanation:
The student's lab results indicate an acid-base imbalance. The normal arterial pH range is 7.35-7.45, while the normal PaCO2 range is 35-48 mm Hg for males and 32-45 mm Hg for females, and the normal total venous bicarbonate (HCO3-) range is 22-29 mEq/L. In this case, the patient has a pH of 7.28 (which is below normal, indicating acidosis), a PaCO2 of 28 mm Hg (which is below normal and indicates a respiratory origin if in the context of compensation), and a bicarbonate level of 18 mEq/L (which is also below normal).
Diagnosing the Imbalance
The decreased pH points to acidosis. Considering both the reduced PaCO2 and the decreased bicarbonate level, this suggests metabolic acidosis with a respiratory compensation. This is because in metabolic acidosis, the body attempts to compensate by hyperventilating to lower the carbon dioxide (hence the low PaCO2 level).
In conclusion, the patient is likely experiencing compensated metabolic acidosis, where the respiratory system is trying to correct the acidotic state by decreasing the PaCO2.