[Clinical application of Acutegastrointestinal injury grading system assocaited with clinical severity outcome in critically ill patients: a multi-center prospective, observational study]

Objective: To investigate the feasibility of utilizing the current acute gastrointestinal injury(AGI) grading system, and explore the association of severity of AGI grade with clinical outcome in critically ill patients. Methods: The adult patients from 14 general ICUs in Zhejiang Province with an expected admission to ICU for at least 24 h were recruited, and all clinical, laboratory, and survival data were prospectively collected. The AGI grade was daily assessed based on GIsymptoms, feeding details and organ dysfunctionon the first week of admission to ICU.The intra-abdominal pressures(IAP) was measured using AbViser device. Results: Of 550 patients enrolled, mean values for age and APACHE Ⅱ score were (64.9±17.2) years and (19.5±7.4), respectively. 456 patients(82.9%) took mechanical ventilation, and 470 patients were identified for AGI. The distribution of AGI grade on the frist day of ICU admission were 50.6%(Ⅰ grade, n=238), 34.2%(Ⅱ grade, n=161), 12.4%(Ⅲ grade, n=58) and 2.8%(Ⅳ, n=13), respectively, while the distribution of the global AGI grade based on the 7-day AGI assessment of ICU admission were 24.5%(Ⅰ grade, n=115), 49.4%(Ⅱ grade, n=232), 20.6%(Ⅲ grade, n=97) and 5.5%(Ⅳ, n=26), respectively. 28- and 60-day mortality rate was 29.3%(n=161) and 32.5%(n=179), respectively. The patients with AGI had a higher 28-(31.1% vs 18.8%, P=0.025) and 60-day survival rate(34.7% vs 20.0%, P=0.01) than those with non-AGI, and also there were positive correlations between AGI grade and 28- and 60-day mortality(P<0.001). Univariate Cox regression analysis showed that age, the source of medicial admission, diabetes mellitus, coronary heart disease, the use of vasoactive drugs, serum creatinine and lactate, mechanical ventilation, APACHE Ⅱ score, the AGI grade in the first day of ICU admission and feeding intolerance within the first week of ICU stay were significantly(P≤0.02) associated with mortality. In multivariate analysis including all these variables, the source of medical admission(χ(2)=4.34, P=0.04), diabete mellitus(χ(2)=3.96, P=0.05), the use of vasoactive drugs(χ(2)=6.55, P=0.01), serum lactate(χ(2)=4.73, P=0.03), the global AGI grade in the 7-day of ICU admission(χ(2)=7.10, P=0.008), and APACHE Ⅱ score(χ(2)=12.1, P<0.001) remained independent predictors for 60-day mortality.In the further subgroup analysis including 402 patients with 7-day survival, the feeding intolerance within the first week of ICU stay could provide independent and incremental prognostic value of 60-day mortality wtih increased χ(2)value of Cox regression model(χ(2)=52.2 vs 41.9, P=0.007) . Conclusion: The AGI grading system is useful for identifying the severity of gastrointestinal dysfunction, and could be used as a strong predictor of impaired outcome. The results provide evidence to support that feeding intolerance within 7 days of admission to ICU was an independent determinant of mortality.

[Multivariate analysis of blood culture positive rate of ICU patients]

OBJECTIVE

To investigate the factors associated with positive results of blood culture and the impact of positive results on the prognosis of patients in ICU of Peking University People's Hospital.

METHODS

We retrospectively analyzed 1 008 blood culture results of 379 critical ill adult patients in ICU from July 1st, 2013 to June 30th, 2014. According to blood culture results, the patients were divided into positive and negative groups. The patients' maximal body temperature, sample collection times, number of bottles within 24 hours, routine hematological variables [(white blood cell count (WBC), percentage of neutrophils (NEU%), lymphocyte count (LYM), platelet count (PLT)], serum C-reactive protein (CRP), usage of antibiotics were compared between the two groups, as well as the patients' gender, age, duration of mechanical ventilation, length of ICU stay and hospital mortality rate.

RESULTS

The total positiverate of blood culture of our study was 15.38%, and the positive rate of patients was 24.27%.When compared between positive group and negative group, the medians of sample collection times were 3 and 1(P<0.000 1); the medians of sample bottles were 4 and 4(P=0.001 2); the medians of WBC were 8.61×10(9)/L and 9.95×10(9)/L(P=0.001 7); and the medians of mechanical ventilation time were 179.5 hours and 47 hours(P<0.000 1); the medians of length of ICU stay were 17 days and 7 days(P<0.000 1), respectively. Hospital mortality rates in positive patients and negative patients were 35.87% and 20.21%(P=0.002 2), respectively. There was no significant difference(P>0.05) between the two groups in body temperature, NEU%, LYM, PLT, CRP or usage of antibiotics.

CONCLUSIONS

Increasing the frequency of sampling and the bottles of blood culture will improve the positive rate of blood culture. The body temperature, WBC, NEU%, LYM, PLT, CRP, us age of antibiotics, gender and age have no effect on the positive rate of blood culture. The patients with positive blood culture results have longer duration of mechanical ventilation, longer ICU stayand higher hospital mortality rate.

Lack of evidence for a cerebral sodium modulating mechanism in the monkey

Experiments were carried out in seven conscious macaque monkeys undergoing a water diuresis to determine the effects of raising carotid blood sodium concentration on renal sodium excretion and free water clearance. On separate days each animal received an intracarotid infusion of hypertonic sodium chloride (90 Eq NaCl/kg.body wt./min) for 5 to 10 min, the same hypertonic infusion intravenously, and an intracarotid infusion of isotonic NaCl. None of the infusions produced a change in sodium excretion. However, the intracarotid hypertonic infusion produced a sustained decrease in free water excretion while the other infusion did not. Creatinine clearance was not affected by any of the infusions. The results of these experiments support the view that while the brain of the primate contains an osmotic sensing mechanism it does not contain a mechanism which modulates sodium excretion.