Discussion
Sever (critical value) hypophosphatemia is rarely reported as one of the complications in acute pancreatitis and, has been attributed mainly to the alcohol abuse (3-6). The patient with alcohol use disorder is at risk to get severe hypophosphatemia, particularly if been admitted to the hospital. This sequence is mostly due to underlying chronic phosphate depletion from the body, complicated by acute shifts of phosphate from the extracellular into the intracellular compartment. (4)
Hypophosphatemia can lead to a variety of symptoms and clinical manifestations (4). The manifestations depend in large part upon the chronicity and severity of the phosphate depletion, it includes muscle pain, bone pain, muscle weakness, altered mental status and numbness, with seizure and even coma in severe life-threatening hypophosphatemia.
Although phosphate depletion is common in admitted patients with alcohol use disorder, the drop in the phosphate level (to less than 0.32 mmol/L), may not become obvious and prominent until twelve to thirty six hours post admission, and it is attributed to movement of phosphate form extracellular into intracellular part (7, 8).
Two factors may contribute to this shift. The first is intravenous dextrose-containing solutions that are usually administered in such situations. Glucose in blood stimulates the release of insulin from pancreas, which promotes phosphate uptake by the cells as phosphorylated glucose intermediates (8). If intravenous dextrose infusion is discontinued, a movement of phosphate into cells may still occur because of refeeding-induced insulin release to the blood (9-10). Even a small amount of 5% dextrose can lead to hypophosphatemia (10-12).
The second factor is acute respiratory alkalosis induced by hyperventilation as a complication of alcohol withdrawal. The increase in extracellular pH (Potential of hydrogen) produces a similar change in pH inside the cells since carbon dioxide (CO2) can rapidly diffuse across cell membranes. The ensuing intracellular increase in pH (alkalosis) stimulates intracellular phosphofructokinase, leading to an increase in glycolysis process and then movement of phosphate into cells. (13)
For our patient, he had one of the above-mentioned conditions, most notably the dextrose infusion he received, which had likely contributed to the drastic decrease of his serum phosphate level. Hypophosphatemic patients with alcohol use disorder may complains with skeletal muscle myopathy due to both alcohol effect and phosphate depletion, they also are at risk of developing rhabdomyolysis (9).