Taylor et al proposed a protocol for replacing phosphorus in a patient in the surgical intensive care unit (ICU) with moderate to severe hypophosphatemia. This can help reduce complications in critically ill patients. The authors are from Barnes-Jewish Hospital and Washington University in St. Louis, Missouri.
Selection: adult (>= 18 years of age) patients in the ICU with hypophosphatemia
Exclusions:
(1) creatinine clearance < 25 mL/min
(2) serum creatinine > 4.0 mg/dL
(3) urine output < 30 mL per hour 2 hours before supplementation
(4) serum calcium corrected for serum albumin < 7.5 mg/dL
(5) corrected calcium * phosphorus product >= 60 mg/dL
(6) receipt of phosphorus containing parenteral nutrition
(7) body weight < 40 kg or > 120 kg
where:
• The correction of the serum calcium for a low serum albumin is discussed earlier in the chapter. One equation is: approximate total serum calcium with normal albumin, in mg/dL = (current total serum calcium in mg/dL) + (0.8 * (4 - (albumin in g/dL)))
Serum Inorganic Phosphorus |
Severity of Hypophosphatemia |
< 1.5 mg/dl |
severe |
1.5 - 2.2 mg/dL |
moderate |
Parameters:
(1) body weight
(2) serum phosphorus concentration
(3) serum potassium
Repletion solution for intravenous (IV) replacement.
Body Weight |
Phosphorus < 1.0 mg/dL |
Phosphorus 1.0 - 1.7 mg/dL |
Phosphorus 1.8 - 2.2 mg/dL |
40 - 60 kg |
30 mmol |
20 mmol |
10 mmol |
61 - 80 kg |
40 mmol |
30 mmol |
15 mmol |
81 - 120 kg |
50 mmol |
40 mmol |
20 mmol |
Serum Potassium |
Phosphorus Cation |
< 4.0 mmol/L |
potassium |
>= 4.0 mmol/L |
sodium |
About two-thirds to three quarters of patients will be corrected after a single IV dose. Additional infusions can be given in those not corrected.
Specialty: Endocrinology, Clinical Laboratory, Nephrology