From the Guidelines
Hypocalcemia in pancreatitis is primarily caused by the intravascular sequestration of calcium by free fatty acids, which create complexes with albumin, thereby reducing serum calcium levels. This process is initiated by the activation of pancreatic pro-enzymes, proinflammatory cytokines, and free radicals in the acidotic environment of the pancreas, as described by L. Gianotti et al. 1. The increased concentration of lipids in the pancreatic capillaries leads to vessel plugging, ischemia, and acidosis, ultimately resulting in the release of free fatty acids and the subsequent sequestration of calcium.
Some key points to consider in the pathophysiology of hypocalcemia in pancreatitis include:
- The role of chylomicrons in the association between pancreatitis and hypertriglyceridemia, which may be more relevant than triglycerides alone 1
- The release of circulating lipase and phospholipase during acute pancreatitis, which can cleave triglycerides and raise serum free fatty acids (FFA) 1
- The importance of recognizing that hypocalcemia is a frequent finding in patients with acute pancreatitis, and that calcium levels below 2 mmol/l are a well-known negative prognostic factor 1
The treatment of hypertriglyceridemia-associated pancreatitis is crucial in improving outcomes and preventing further pancreatic damage, as noted by L. Gianotti et al. 1. This can be achieved by avoiding lipid emulsions if parenteral nutrition is needed, maintaining triglyceride levels within the normal range, and using drug therapy to decrease VLDL production if necessary. Regular monitoring of serum triglycerides is essential when administering lipids, and the use of intravenous lipids as part of parenteral nutrition in severe acute pancreatitis is feasible as long as hypertriglyceridemia is avoided.
From the Research
Pathophysiology of Hypocalcemia in Pancreatitis
- Hypocalcemia is a frequent finding in acute pancreatitis, with severe cases presenting neurological and cardiovascular manifestations 2.
- The correction of hypocalcemia by parenteral calcium infusion is a controversial topic, as intracellular calcium overload is a central mechanism of acinar cell injury in pancreatitis 2.
- Hypoalbuminaemia is a common cause of low serum calcium in acute pancreatitis, with studies showing a significant correlation between uncorrected total serum calcium and serum albumin levels 3.
- Deficiency of parathyroid hormone due to its destruction by proteolytic enzymes or parathyroid gland exhaustion is suggested as a major factor inducing persistent hypocalcemia in acute pancreatitis 4.
Causes of Hypocalcemia
- Hypoalbuminaemia is the most common cause of a low serum calcium in acute pancreatitis, with 64.4% of serum calcium results in the apparently hypocalcaemic range 3.
- Parathyroid hormone-mediated disorders, such as postsurgical hypoparathyroidism, are a common cause of hypocalcemia 5.
- Non-PTH mediated disorders, such as vitamin D deficiency, can also cause hypocalcemia 5.
Treatment of Hypocalcemia
- Intravenous calcium infusion is essential to raise calcium levels and resolve or minimize symptoms in the setting of acute hypocalcemia 5.
- Oral calcium and/or vitamin D supplementation is the most frequently used treatment for chronic hypocalcemia 5.
- Recombinant human parathyroid hormone (rhPTH) has been approved for the treatment of hypoparathyroidism, but its high cost requires strict selection of candidates 5.
- Calcium administration has been shown to have no association with multiple mortality and is significantly associated with prolonged length of stay in the hospital and ICU in patients with acute pancreatitis and hypocalcemia 6.