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).