Final answer:
Normal PCO2 levels in the blood range from 35 to 45 mmHg and the best lab tests for diagnosing scabies include skin scraping or biopsy to identify the mites or their eggs.
Step-by-step explanation:
Normal PCO2 levels in the blood would range from 35 to 45 mmHg. However, in acidosis, the PCO2 level initially remains normal, but decreases as compensation occurs in the body to restore the proper balance of bicarbonate and carbonic acid/CO2.
The best lab tests for diagnosing scabies include a skin scraping or biopsy to identify the mites or their eggs. These tests can be done in a laboratory and help confirm the presence of scabies mites.