Final answer:
In the case of high pH, high HCO₃⁻ and PCO₂, and elevated urinary Cl⁻, the patient appears to have metabolic alkalosis. The increase in PCO₂ and high urine chloride suggest that both respiratory and renal compensations are occurring to correct the pH imbalance.
Step-by-step explanation:
When analyzing a scenario where the pH is high, HCO₃⁻ is high, and PCO₂ is high, and Cl⁻ in the urine is > 20, we are considering a case of metabolic alkalosis. Metabolic alkalosis is indicated by an elevated blood pH and excess bicarbonate (HCO₃⁻).
Initially, in metabolic alkalosis the PCO₂ would be normal, but to achieve compensation the PCO₂ would increase as the body attempts to reestablish the proper ratios of bicarbonate and carbonic acid/CO₂ through respiratory compensation mechanisms. However since Cl⁻ in the urine is high, that would indicate an attempt by the kidneys to conserve bicarbonate suggesting that there is some form of renal compensation as well.