Home | | Anesthesiology | Hypophosphatemia

Chapter: Clinical Anesthesiology: Perioperative & Critical Care Medicine: Management of Patients with Fluid & Electrolyte Disturbances

| Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail |

Hypophosphatemia

Hypophosphatemia is usually the result of either a negative phosphorus balance or cellular uptake of extracellular phosphorus (an intercompartmental shift).

HYPOPHOSPHATEMIA

 

Hypophosphatemia is usually the result of either a negative phosphorus balance or cellular uptake of extracellular phosphorus (an intercompartmental shift). Intercompartmental shifts of phosphorus can occur during alkalosis and following carbo-hydrate ingestion or insulin administration. Large doses of aluminum or magnesium-containing ant-acids, severe burns, inadequate phosphorus sup-plementation during hyperalimentation, diabetic ketoacidosis, alcohol withdrawal, and prolonged respiratory alkalosis can all produce a negative phos-phorus balance and lead to severe hypophosphate-mia (<0.3 mmol/dL or <1.0 mg/dL). In contrast to respiratory alkalosis, metabolic alkalosis rarely leads to severe hypophosphatemia.

Clinical Manifestations of Hypophosphatemia

 

Mild to moderate hypophosphatemia (1.5–2.5 mg/ dL) is generally asymptomatic. In contrast, severe hypophosphatemia (<1.0 mg/dL) is often associ-ated with widespread organ dysfunction. Cardio-myopathy, impaired oxygen delivery (decreased2,3-diphosphoglycerate levels), hemolysis, impaired leukocyte function, platelet dysfunction, encepha-lopathy, skeletal myopathy, respiratory failure, rhab-domyolysis, skeletal demineralization, metabolic acidosis, and hepatic dysfunction have all been asso-ciated with severe hypophosphatemia.

Treatment of Hypophosphatemia

 

Oral phosphorus replacement is generally preferable to parenteral replacement because of the increased risk of phosphate precipitation with calcium, result-ing in hypocalcemia, and also because of the increased risks of hyperphosphatemia, hypomagnesemia, and hypotension. Accordingly, intravenous replacement therapy is usually reserved for instances of symptom-atic hypophosphatemia and extremely low phosphate levels (<0.32 mmol/L). In situations where oral phos-phate replacement is utilized, vitamin D is required for intestinal phosphate absorption.

Anesthetic Considerations

 

Anesthetic management of patients with hypophos-phatemia requires familiarity with its complications (see above). Hyperglycemia and respiratory alkalo-sis should be avoided to prevent further decreases in plasma phosphorus concentration. Neuromus-cular function must be monitored carefully when NMBs are given. Some patients with severe hypophosphatemia may require mechanicalventilation postoperatively because of muscle weakness.

Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail


Copyright © 2018-2020 BrainKart.com; All Rights Reserved. Developed by Therithal info, Chennai.