Recently, we have had three patients on an intensive insulin drip during hypothermia. During the rewarnt, each patient had two episodes of hypoglycemia requiring dextrose IV. What is the rationale for these phenomena?

摘要

Hypothermia induces a variety of physiologic changes in the body (Scaravilli et al., 2012). Most enzyme systems are temperature-dependent, which influences the enzyme-mediated reactions. Research in animal models has shown that hypothermia induces changes in blood glucose homeo-stasis. According to those studies, hypothermia reduced glucose utilization, reduced insulin secretion by pancreatic islet cells, and increased resistance to exogenous insulin (Blackard et al, 1967; Sasaki et al, 1982; Escolar et al, 1987,1990).There is only one human study that examined the impact of blood glucose in patient with induced hypothermia, and this study concluded that mild hypothermia is associated with higher blood glucose levels, increased blood glucose variability, and greater insulin requirements compared with normothermia (Cueni-Villoz et al., 2011). Therefore, during hypothermia, patients require higher doses of insulin to control blood glucose. As the patient is rewarmed, they progress toward normal blood glucose homeostasis and the sensitivity to insulin normalizes (Scaravilli et al., 2012). The use of the high dose of insulin to control the patient blood glucose during the hypothermia phase can lead to hypoglycemia during the rewarming phase.