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Objective:To evaluate the effect of airway driving pressure (ΔP) guided sedation strategy on the prognosis of patients with mechanical ventilation.Methods:Patients who needed invasive mechanical ventilation and admitted to the department of intensive care unit (ICU) of Jiangxi Provincial People's Hospital from January 2017 to December 2018 were enrolled. The patients were divided into study group and control group according to the random number table. After informed consent of patients or their families, both groups received routine treatment in ICU. The control group was treated with light sedation strategy, the Richmond agitation sedation score (RASS) was performed every 4 hours, and the target was RASS > -3. ΔP in the study group was measured once a day, and the sedative target of patients with low driving pressure (ΔP ≤ 14 cmH 2O, 1 cmH 2O = 0.098 kPa) was RASS > -3, while the patients with high driving pressure (ΔP > 14 cmH 2O) was RASS ≤ -3. The evaluation was conducted at 28 days after admission to ICU, and the patients were followed up to 60 days. The main outcome was days without mechanical ventilation in 28 days. The secondary outcomes were the rate of extubation, discharge outcome, incidence of ventilator associated pneumonia (VAP) and delirium, and 60-day survival rate. Results:A total of 60 patients with respiratory failure due to various reasons were recruited, 30 in each group. There was no significant difference in gender, age, primary disease, severity of disease or ΔP between the two groups. The days without mechanical ventilation within 28 days in the study group were significantly more than that in the control group [days: 20 (0, 23) vs. 12 (0, 16), P = 0.018], and the incidences of VAP (3.3% vs. 16.7%, P = 0.045) and delirium (0% vs. 10.0%, P = 0.038) were significantly lower than that in the control group. There were no significant differences in the rate of extubation (73.3% vs. 66.7%, P = 0.273), discharge outcome [improvement (cases): 24 vs. 21, unhealed (cases): 2 vs. 5, deaths (cases): 4 vs. 4, P = 0.506] and 60-day survival rate (83.3% vs. 76.7%, P = 0.519) between the study group and control group. Conclusion:Compared with light sedation strategy, ΔP directed sedation strategy can effectively shorten the duration of mechanical ventilation and reduce the incidence of VAP and delirium in the ICU patients.
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Objective To analyze the main characteristics of air pollution in Nanchang City, and discuss the correlation between air pollution exposure (especially PM2.5) and the development of pneumonia related intensive care unit (ICU) patients and their lag effect.Methods 2454 patients who lived in Nanchang City admitted to ICU of Jiangxi Provincial People's Hospital from January 1st, 2014 to December 31st, 2016 were enrolled. According to the diagnosis, the patients were divided into pneumonia group (156 cases) and non-pneumonia group (2298 cases). The general clinical characteristics of patients and air pollution concentration in Nanchang in the year between 2014-2016 were collected. Multiple regression model was used to analyze the influence of meteorological factors on the condition of ICU patients associated with pneumonia. Using odds ratio (OR), the correlation intensity of air pollution exposure and pneumonia related ICU patients' development was reflected, and the confidence level of association intensity was reflected by the 95％ confidence interval (95％CI). The distribution lag nonlinear model (DLNM) was established to evaluate the effect of air mass parameters on the time lag effect.Results The results of air pollution analysis in Nanchang City in the year between 2014-2016 showed that the annual average concentration of carbon monoxide (CO), sulfur dioxide (SO2) and nitrogen dioxide (NO2) was low and maintained at the same level in the year between 2014-2016. The annual average concentration of CO and NO2 increased in the year between 2014-2016, but the average annual concentration of SO2 decreased rapidly in the year between 2014-2016, and the average annual concentration of PM2.5 tended to slow down after the year between 2014-2016. The annual average concentration of PM10 decreased in the year between 2014-2016, but continued to rise in the year between 2014-2016. The annual mean concentration of O3 showed a trend of continuous increase from the year between 2014-2016. The age of pneumonia group was generally higher than that of non-pneumonia group, most of them were male, and had higher expected mortality and acute physiology and chronic health evaluation Ⅱ(APACHEⅡ) score. The average air temperature in the pneumonia group was lower than that in the non-pneumonia group on the day of entering the group, and the air pollutants such as PM2.5 and PM10 were significantly higher than those in the non-pneumonia group. The analysis of multiple regression models showed that PM2.5 and air temperature were significantly related to patients with ICU pneumonia on the day of entry (PM2.5:OR = 1.02, 95％CI =1.00-1.03,P < 0.05; air temperature:OR = 0.96, 95％CI = 0.92-0.98,P < 0.05), and the effect of PM2.5 on patients with ICU pneumonia could last for at least 5 days (OR = 1.04, 95％CI = 1.00-1.09,P < 0.05), and the effect disappeared until the 7th day. According to the analysis of the influence of different concentrations of PM2.5 on ICU pneumonia patients, when the PM2.5 concentration reached 200μg/m3, its effect on ICU pneumonia patients would last for 5 days (OR = 1.45, 95％CI = 1.07-1.76,P < 0.01).Conclusion PM2.5 and air temperature are significantly related to the condition of ICU patients with pneumonia, and the influence of high concentration of PM2.5 on ICU patients with pneumonia has a lag effect.
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BACKGROUND: Schwann cells play an important role in axonal growth and myelin sheath formation of the peripheral nerve. Whether Schwann cells play the same role in the spinal cord had attracted considerable attention. Microencapsulation technology as an effective immune isolation technique can effectively keep Schwann cell activity to play the repair effect of Schwann cell in the spinal cord.OBJECTIVE: To observe the changes of myelin sheath in the injured transection of rats after transplantation of the alginic acid microencapsulated Schwann cells.DESIGN, TIME AND SETTING: The randomized controlled animal experiment was performed at the Basic Medical School of Nanchang University from March 2005 to February 2008.MATERIALS: Sciatic nerve trunk was obtained from adult rabbits to harvest Schwann cells in vitro using repeatedly differential velocity adherent technique, and to prepare Schwann cell suspension and microencapsulated Schwann cell suspension.METHODS: A total of 146 adult Sprague Dawley rats were used to establish models of right hemi-transection damage at T_(10) level and randomly assigned to four groups: simple injury group (n=44), cell transplantation group (n=44), microencapsulated cell transplantation group (n=44) and normal control group (n=14). At 1, 3, 7,14 and 28 days following surgery, 8 rats were selected from each group at each time point (2 from the normal control group) for perfusion and fixation. Spinal cord tissue was collected to make paraffin section, and then subjected to hematoxylin-eosin staining and Loyez myelin staining. In addition, 2 rats were selected from each group at 2 and 8 weeks. The spinal cord tissue was fixed, embedded in Epon816, stained using uranyl acetate and aluminum citrate, and then observed using an electron microscope.MAIN OUTCOME MEASURES: Neuron number and survival were observed surrounding the damaged region. Structural changes in the myelin sheath from spinal cord white substance at the damage site were measured.RESULTS: At 1 and 3 days following spinal cord injury, spinal neurons were degenerated and necrotic at damaged site, with reduced number of myelin sheath, loose structure, but above-mentioned was rare in the cell transplantation and microencapsulated cell transplantation groups. At 7 days, the reduced number of myelin sheath, with damaged structure was seen. The microencapsulated cell transplantation group was light. At 14 days, number of neurons was increased, with increased cell body, especially in the microencapsulated cell transplantation group. At 28 days, neurons gradually recovered, myelin sheath was gradually complete, with increased number in the microencapsulated cell transplantation group. There were significant differences compared with the simple injury and cell transplantation groups (P < 0.01). At 8 weeks, abundant myelin sheath was repaired, with new myelin sheath in the microencapsulated cell transplantation group.CONCLUSION: Microcapsule has immune isolation effects. Microencapsulated rabbit Schwann cells can promote the repair of rat spinal cord neurons and axonal myelinization.