The corrected calcium needs to be calculated when the serum albumin is high, serum albumin is low, serum calcium is low, and ionized calcium is low. Which of the following is the correct equation to calculate the corrected calcium?
1) Corrected calcium = serum calcium + 0.8 * (4 - serum albumin)
2) Corrected calcium = serum calcium + 0.8 * (4 + serum albumin)
3) Corrected calcium = serum calcium - 0.8 * (4 - serum albumin)
4) Corrected calcium = serum calcium - 0.8 * (4 + serum albumin)