Objective To explore the efficacy of insulin pump on glycemic control in neurocritical patients. Methods 42 patients were randomly divided into treatment group (21 cases) and control group (21 cases), the treatment group was treated with insulin pump (CSII); the control group was treated with multiple subcutaneous insulin injection (MSII). Results: The CSII group was able to control fasting and postprandial blood glucose better, and there was no significant hypoglycemia and other complications, which was significantly different from the control group (p<0.05). Conclusion CSII can better control fasting and postprandial blood glucose in neurocritical patients. The high incidence of stress hyperglycemia in neurocritically ill patients is a prominent and common clinical problem and may be a factor in secondary brain damage, and the degree of elevated blood glucose is related to the site, size and degree of disease, as well as the degree of coma, complications and prognosis. Since January 2006 to February 2007, we applied insulin pump (Medtronic 507) to treat 42 cases of neurocritical patients with combined hyperglycemia with remarkable efficacy, now reported as follows: 1, object and method 1.1 Objects: all the cases are hospitalized in our hospital, in line with the criteria for admission to the Neurological Intensive Care Unit (NICU) [1]. Among them, 24 cases were male and 18 cases were female, aged 39-72 years old, with an average of 58.2 years old. There were 26 cases of acute cerebrovascular accident, 4 cases of craniocerebral injury, 6 cases of viral encephalitis, 1 case of multiple sclerosis, 2 cases of myasthenia gravis, and 3 cases of metabolic encephalopathy. There were 34 cases of pre-existing diabetes mellitus, and all of them were randomized to have blood glucose >15.0 mmol/L after admission.The remaining 8 cases were randomized to have blood glucose >20.0 mmol/L. They were randomly divided into the treatment group (CSII) and the control group (MSII), and there was no significant difference in the comparison of the age and gender of patients in the two groups (p>0.05). 1.2 Methods: 1.2.1 Treatment method The starting total amount of daily insulin (Novolin) in the CSII group was 0.6 u/kg, and the basal amount and the loading amount before three meals each accounted for 50% of the total amount.In the MSII group, Novolin was used according to blood glucose, with the starting dose of 0.5 u/kg.Both groups were given standard calories for diabetes and other treatments and so on. 1.2.2 Observation items Monitor fasting, before three meals, 2h after meals and bedtime blood glucose, some patients add 0am, 3 am blood glucose. 1.2.3 Statistical methods Data were expressed as mean + standard deviation (x+s), and t-test was used for comparison before and after treatment. 2.Results 2.1 The time taken to reach the blood glucose standard in the CSII group was significantly shorter than that in the MSII group (p<0.05), and the daily insulin dosage in the CSII group was also significantly smaller than that in the MSII group (p<0.05). 2.2 Adverse reactions There was no hypoglycemia and dawn phenomenon in the CSII group, while 2 cases of hypoglycemia and 3 cases of dawn phenomenon occurred in the MSII group. 3.Discussion Combined diabetes mellitus and stress hyperglycemia in neurocritical patients is a common problem, which has become an independent risk factor affecting the prognosis of critically ill patients by affecting the metabolic state of the body, immune function, and increasing the occurrence of infections and other complications. The results of experimental and clinical studies show that elevated blood glucose after brain injury is one of the most important causes of death and disability in patients, and forms a vicious circle with brain cell damage. The mechanism of elevated blood glucose is related to changes in glucose-regulating hormones, massive application of corticosteroids, peripheral insulin levels and insulin resistance, and previous comorbidities such as diabetes mellitus. In critically ill patients, the diagnostic criteria for stress hyperglycemia are unclear, and elevated glycated hemoglobin levels (>6%) can evaluate the glycemic profile over the past 2-3 months, but cannot be used as a diagnostic criterion for diabetes mellitus. The circulating blood glucose level also reflects the degree of elevated blood glucose in the brain, and the damage to brain cells caused by high blood glucose may come from the following aspects: (1) increased anaerobic fermentation of sugar, leading to increased lactic acid production, especially in ischemic and hypoxic conditions, a large amount of lactic acid is produced and accumulates, resulting in lactic acidosis in the brain; (2) increased production of free radicals; (3) enhanced anaerobic metabolism, resulting in impaired energy production and decreased mitochondrial ATP production; the above-mentioned levels of glucose are not a diagnostic criterion. ATP production is reduced; all of the above changes can lead to and aggravate brain cell edema and increased intracranial pressure, exacerbating the metabolic disorders of brain cells and further aggravating brain damage. When stroke is combined with hyperglycemia, if the blood glucose level is >16.7 mmol/L, it suggests that the damage to brain tissues is wider and more serious, and it is one of the indicators of poor prognosis, and controlling blood glucose is the key to prevention and treatment. The traditional concept is that elevated blood glucose is a compensatory response to the need for energy metabolism after stress, however, more and more studies have confirmed that the degree of elevated blood glucose is closely related to the prognosis of patients with craniocerebral injuries, strokes, subarachnoid hemorrhage, etc. The same is true for the elevation of blood glucose after stress in patients with previous diabetes mellitus. And the control of hyperglycemia can improve their prognosis. Nowadays, blood glucose control strategy has become an aspect of comprehensive treatment for critical illnesses. Nutritional support with exogenous insulin intensive therapy and strict control of blood glucose level, on the one hand, effectively controls the elevation of blood glucose due to large amounts of glucose infusion, and at the same time ensures the adequate supplementation and effective utilization of nutrient substrates, restores cellular metabolism and ensures the supply of energy. Insulin pump therapy can mimic the insulin secretion of normal people, and it injects micro-insulin (basal amount) into the patient’s body 24 hours a day without interruption, and then injects additional amount when eating, the basal amount can not only inhibit the decomposition of hepatic gluconeogenesis, but also inhibit the decomposition of fats and the production of ketone bodies. It can also inhibit the process of gluconeogenesis in the emergency state. In addition, the basal and additional volume can be adjusted at any time, so that hypoglycemia is not easy to occur, and fasting blood glucose and nighttime blood glucose can be maintained better. In recent years, insulin has been found to have many effects other than lowering glucose, such as improving the immune function of the body, increasing the chemotaxis and phagocytosis of leukocytes and monocytes, reducing the chances of infections, and decreasing cardiovascular and cerebrovascular accidents. It has been reported that CSII makes the absorption rate of conventional insulin in the subcutaneous tissue fluctuate <2.8%, while the absorption rate of the subcutaneous tissue of various insulin preparations of MSII fluctuates between 10% and 52% of the injected dose, so the incidence of hypoglycemia in the CSII group is lower than that in the MSII group [4]. Therefore, the efficacy of CSII in the treatment of combined diabetes mellitus and stress hyperglycemia in patients with neurocritical illness is remarkable and worthy of clinical promotion.