Question

The combined calcium and phosphorus in a pn should not exceed 45 meq/l. what is the combined calcium and phosphorus (there are 2 meq po4/mmol) in this pn order and is it considered safe?

Answer 1

The combined calcium and phosphorus in a PN order can be calculated using molar solubility values and the conversion factor for phosphorus to meq/L. If the calculated value is within the limit of 45 meq/L, the PN order is considered safe.

Step-by-step explanation:

The molar solubility of calcium phosphate at 25°C is 2.07 × 10¯³M. Since the molarity of the ions is 2x for phosphate and 3x for calcium, we can calculate the concentrations of each ion to be [PO4³⁻] = 2.28 × 10¯⁷M and [Ca²⁺] = 3.42 × 10¯⁷M.

In a PN order, assuming that the calcium and phosphorus are in the form of calcium phosphate, you need to convert the concentrations of each ion to meq/L. The conversion factor for phosphorus is 2 meq/mmol. So, the combined calcium and phosphorus in the PN order can be calculated as 2 * [PO4³⁻] + [Ca²⁺] = 2 * (2.28 × 10¯⁷M) + (3.42 × 10¯⁷M).

After calculating the value, you can compare it to the limit of 45 meq/L. If the calculated value is less than or equal to 45 meq/L, then the PN order is considered safe.

Answer 2

The combined calcium and phosphorus given that there are 2 meq po4/mmol is equal to 30 meq/l. We just multiply the given data to the density of the combined elements. since the limit is 45 meq/l, then the dosage is considered as safe for the patient to have.