1.Gut Protective Effect of Rhubarb and Glutamine on Intestinal Ischemia Reperfusion Rats
Jiayan SUN ; Dingyu TAN ; Hairong ZHU ; Zhongfang XIA
Journal of Medical Research 2006;0(10):-
Objective To observe and compare the protective effect of rhubarb and Gln on morphology and permeability of rats intestine after SMA ischemia reperfusion.Methods 40 male rats were divided into rhubarb ,Gln, control and pseudosugery group(n=10)randomly. The intestinal I/R model of rhubarb ,Gln and control group rats was established and TPN was done.Rhubarb ,Gln and normal saline were given orally in rhubarb,Gln and control group respectively. SMA was decoherenced but not blocked in control group. Urine ,intestine,MLN and portal vein blood were collected for L/M,morphology and bacterial translocation study.Results (1)L/M was significant high in control group compared with pseudosugery group(P
2.The efficacy of hypertonic saline treatment in cardiopulmonary resuscitation in animal model with cardiac arrest:a Meta-analysis
Wei LI ; Jun XU ; Dingyu TAN ; Xuezhong YU
Chinese Critical Care Medicine 2015;31(3):197-202
ObjectiveTo evaluate the efficacy of hypertonic saline (HS) treatment in cardiopulmonary resuscitation (CPR) in animal models of cardiac arrest (CA).Methods PubMed and EMBASE data were retrieved from January 1st, 1966 to September 30th, 2014, and Wanfang data and CNKI were searched from January 1st, 1990 to September 30th, 2014 for randomized controlled trials (RCTs) regarding CPR intervention of CA animal models with HS. HS was intravenously infused at the initiation of CPR in HS group, without limiting its dosage or concentration. The same volume of normal saline (NS) was given in NS group. Meta-analysis concerning the rate of restoration of spontaneous circulation (ROSC), the serum sodium concentration before CA and during CPR, and related hemodynamic parameters, including mean arterial pressure (MAP) and coronary perfusion pressure (CPP) at the immediate beginning of CPR and 90 minutes after ROSC was conducted by RevMan 5.3 software.Results A total of 8 RCTs were included. Meta-analysis showed that compared with NS group, the rate of ROSC [relative risk (RR) = 1.23, 95% confidence interval (95%CI) = 1.05-1.43,P = 0.010], serum sodium concentration during CPR [weight mean difference (WMD) =17.44, 95%CI = 12.57-22.31,P< 0.01], and the level of MAP at 90 minutes after ROSC (WMD = 4.81, 95%CI =1.58-8.03,P = 0.003) were significantly improved in HS group. There was no significant statistic difference in other hemodynamic parameters, including serum sodium concentration before CA (WMD = 0.78, 95%CI = -0.26-1.82,P =0.14), MAP (WMD = 5.43, 95%CI = -0.74-11.59,P = 0.08) and CPP at the immediate beginning of CPR (WMD =6.82, 95%CI = -5.54-19.19,P = 0.28), and CPP at 90 minutes after ROSC (WMD = -0.77, 95%CI = -10.33-8.80, P = 0.88) between two groups. It was showed by funnel chart that bias was not significant in the published articles. Conclusion This systematic review indicates that HS infusion is followed by an improved ROSC rate, serum sodium concentration during CPR, and MAP at 90 minutes after ROSC in animal models of CA.
3.Advances of ventilation during cardiopulmonary resuscitation
Dingyu TAN ; Yangyang FU ; Jun XU ; Xuezhong YU
Chinese Critical Care Medicine 2016;28(7):661-665
As one of the cornerstones of modern cardiopulmonary resuscitation (CPR), ventilation received controversy and challenges in the past two decades. From 2000 to 2015, the changes in CPR guidelines of American Heart Association (AHA) showed that the position of ventilation declined gradually as compared to chest compressions. Chest compressions only CPR has been strongly advocated in recent years, especially in witnessed cardiogenic cardiac arrest (CA). Passive oxygenation and cardiocerebral resuscitation (CCR) also showed good effect in the early stage of cardiogenic CA. However, clinical validation in a larger context is still needed. An impedance threshold device (ITD) transiently blocks air from entering the lungs during recoil, decreases the intrathoracic pressure, facilitates venous return to the chest and increases coronary blood flow. However, the relevant research findings are not consistent, and the guidelines do not recommend routine use of ITD. Positive-pressure ventilation, which can increases intrathoracic pressure, affects the coronary perfusion pressure (CPP) and cerebral perfusion, is thought to be not only useless, but also has adverse effects within the first few minutes of CPR. This view is accepted by many scholars, however, ventilation is essential in late-start CPR, prolonged CPR and non-cardiogenic CA. Mechanical ventilation, especially special ventilation modes for CPR showed some prospects. Positive-pressure ventilation remains the gold standard in CPR in clinical practice at present. It was shown by existing research that hyperventilation significantly reduce the success rate of resuscitation, thus a consensus had been reached about avoiding hyperventilation. Currently, the number of studies on ventilation during CPR is very limited, and many of the conclusions are not consistent among studies. Therefore, more high-quality studies are needed in future to further clarify the application of ventilation during CPR.
4.The value of combination of the mortality in emergency department sepsis score and blood lactate level in the risk stratification of severe sepsis in the emergency department
Dingyu TAN ; Zhongfang XIA ; Aidong ZHENG ; Chun ZHOU
Chinese Critical Care Medicine 2014;26(3):159-164
Objective To evaluate the combination of the mortality in emergency department sepsis (MEDS) score with blood lactate level in the risk stratification of patients with severe sepsis in the emergency department (ED).Methods 665 adult patients with severe sepsis admitted from May 2011 to December 2012 in ED were found to be eligible for the study.MEDS score,acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score,and arterial blood lactate was determined,and the outcomes in 28 days were recorded.Logistic regression analysis was used to evaluate the relationship between each predictive factor score and prognosis.Each predictive factor was compared with the areas under the receiver operating characteristics (ROC) curve (AUC).Results The mortality in 28 days was 34.6% in 665 patients.The mortality in group of MEDS score 12-27 was significantly higher than that group of MEDS score<12 [51.0% (156/306) vs.20.6% (74/155),x2=28.414,P=0.000].In the meantime,APACHE Ⅱ score and blood lactate level were also significantly higher in group of MEDS score 12-27 than those in group with MEDS score<12 [APACHE Ⅱ score:26.4 ± 10.6 vs.21.7 ± 8.1,t=-3.555,P=0.002; lactate (mmol/L):4.9 (2.3,9.9)vs.3.9 (1.5,8.9),Z=-2.352,P=0.023].Kaplan-Meier survival analysis showed significantdifference in the two groups (the Log Rank test 36.71,P <0.01).The levels of 3 predictive factors were predominantly higher in non-survivors than survivors [MEDS score:14.1 ± 6.7 vs.8.2 ± 4.5,t=-6.929,P=0.000; APACHE Ⅱ score:28.1 ±7.1 vs.22.2± 11.3,t=-6.472,P=0.000; lactate (mmol/L):5.4 (2.9,11.0) vs.3.8 (1.2,9.1),t=-6.472,P=0.004].The AUCs were 0.813,0.706 and 0.727 for MEDS score,APACHE Ⅱ score and blood lactate respectively.The predictive ability for 28-day mortality of MEDS score was better than blood lactate (P=0.008) and APACHE Ⅱ score (P=0.005).The AUC of MEDS score combined with lactate was 0.865,and 28-day mortality prediction was better than MEDS score (AUC 0.865 vs.0.813,P<0.001).The sensitivity (83.1%),specificity (93.2%),positive prediction value (PPV,62.4%),and negative prediction value (NPV,92.1%) for MEDS score combined with lactate were highest among all predictors.Conclusion MEDS score combined with lactate is a good risk stratification tool for emergency patients with severe sepsis,and its prognostic capability is better than either MEDS score,APACHE Ⅱ score or blood lactate.
5.Analysis of early clinical risk factors of severe acute organic fluorine inhalation poisoning
Ping GENG ; Jiyang XU ; Zhongfang XIA ; Lu FAN ; Min XU ; Dingyu TAN ; Aiwen MA ; Jinsong ZHANG
Chinese Journal of Integrated Traditional and Western Medicine in Intensive and Critical Care 2014;(5):345-349
ObjectiveTo investigate the early clinical risk factors of severe acute inhaled organic fluorine poisoning.Methods The clinical data of patients with acute poisoning of organic fluorine inhalation admitted since 2004 in Northern Jiangsu People's Hospital were retrospectively analyzed. According toDiagnostic Criteria of Occupational Acute Fluorohydrocarbon Poisoning(GBZ66-2002), all the patients were divided into three groups: mild, moderate and severe poisoning groups, the severe cases were included in the intensive group, and the others were grouped in the non-intensive group. The contents in the survey were as follows: gender, age, vital signs on admission (body temperature, pulse rate, respiratory rate, systolic blood pressure), arterial blood gas analysis record〔arterial oxygen saturation(SaO2), oxygenation index(PaO2/FiO2), lactic acid(Lac) and arterial partial pressure of carbon dioxide(PaCO2), pH value(pH)〕. Before treatment, the white blood cell(WBC) count, platelet(PLT) count, levels of alanine transaminase(ALT), creatinine(Cr), blood glucose, electrolytes(potassium, sodium, chloride, calcium), creatine kinase isoenzyme(CK-MB), etc. were examined and recorded. All the patients were immediately arranged for bedside chest X-ray examination, and the chest X-ray lung injury scores were recorded. By univariate and multivariate logistic regression analyses, the receiver operating characteristic curve(ROC curve) was drawn to evaluate the diagnostic value of the clinical risk factors.Results Sixty-two cases consisting with the standard criteria of enrollment were collected in the study, 36 cases being in intensive group and 26 cases in non-intensive group. The univariate analysis showed that the differences in pulse rate, respiratory rate, PaO2/FiO2, WBC, SaO2, Lac, pH, and lung injury score were statistically significant(P<0.05 orP<0.01). Logistic multiple regression analysis showed that PaO2/FiO2, WBC, Lac and chest X-ray lung injury score were the four indexes for predicting the independent risk factors of severe acute inhaled organic fluorine poisoning. The area under ROC curve(AUC) of PaO2/FiO2 was the highest(0.884), 95% confidence interval(95%CI) was 0.784 - 0.984, the critical value was 96.5 mmHg(1 mmHg=0.133 kPa), with the sensitivity of 75.6%, specificity of 95.2%, positive predictive value(PPV) of 92.3% and the negative predictive value(NPV) of 71.4%, in sequence, the rest were WBC(AUC 0.846, 95%CI 0.728 - 0.965, the criticalvalue 12.15×109/L), Lac(AUC 0.800, 95%CI 0.662 - 0.938, the critical value 4.2 mmol/L), chest X-ray lung injury score(AUC 0.795, 95%CI 0.652 - 0.938, the critical value 2.50), the sensitivity of the above three items was 90.2%, 83.6%, 88.5%, specificity was 90.2%, 83.6%, 88.5%, the PPV was 86.7%, 82.4%, 85.8% and NPV was 72.0%, 73.9%, 69.2% respectively.ConclusionThe blood WBC count, Lac, PaO2/FiO2 and chest X-ray lung injury score can be used as the early clinical risk factors of severe acute inhaled organic fluorine poisoning.
6.Expression and clinical significance of platelet activating factor (PAC-1), CD629P and thrombus precursor protein (TpP) in severe sepsis
Ping GENG ; Jinsong ZHANG ; Zhongfang XIA ; Jian GU ; Min XU ; Jiyang XU ; Dingyu TAN ; Songgang XIE ; Lianjun SHEN ; Aiwen MA
Chinese Journal of Emergency Medicine 2008;17(10):1080-1084
Objective To investigate the expression and clinical significance of platelet activating factor [PAC]-1, CD62P and TPP hi severe sepsis. Method Patients with severe sepsis who were admitted into the EICU of Subei People's Hospital from April 2007 to March 2008 were included. Patients with severe sepsis (Group Ⅲ)were treated according to the treatment guidelines for severe sepsis, and were divided, according to their clinical records, into those who survived and those who died within 28 days of admission. Patients admitted during the same period with symptoms of infection but without severe sepsis were included as the General Infected Group (Group Ⅱ). A Control Group (Group Ⅰ) comprised patients who visited the hospital over the same period for physical examination or the healthy volunteers. The group members were all included randomly, and the gender and sex of patients in all three groups were similar. Patients with acute brain infarction, acute coronary syndrome,serious diabetes, hyperlipidemia, malignant tumor, leukemia, primary liver, renal and hematopoietic system dis-eases,long-term bedridden patients, pregnant women, and patients taking hormone treatment or hranunosuppres-sants were excluded from the study. Morning venous blood was collected and ELISA and Flow Cytometry performed on the fwst day of admission for Groups Ⅰ- and Ⅱ, and on the first, third and fifth day after admission for Group Ⅲ, to determine the TpP,PAC-1 and CD62P respectively; and the Marshall score was determined. Data were ana-lyzed by SPSS 12.0 software. For continuous variables, comparisons among groups were analyzed by ANOVA.Levene's and LSD test were applied to assess homogeneity. Bivariate test is applied to Correlation Analysis. P<0.05 was regarded as a statistically significant difference. Results There were a total of 20 patients each in GroupⅠ-and GroupⅡ, and 30 in Group Ⅲ; of these, 19 were classed as survivors and 11 died during the 28-day peri-od. On the first day of admission, there were no significant differences in PAC-1, CD62P or TpP expression between Groups Ⅰ- and Ⅱ(P>0.05); however, Group Ⅲ was significantly different compared with both Group Ⅰ and Group Ⅱ (both:P<0.05). The expression of PAC-1, CD62P and TpP tended to decline in the survivor group,and became normal with the treatment process, while the expression of PAC-1 ,CD62P and TpP in the patients who died remained high, and even increased significantly over time. On the first day, the expression of CD62P and TpP in the patients who survived and in those who died was not significantly different (P>0.05); on the third day,however, a significant difference appeared with values of (2.89±1.48) % vs. (5.04±2.57) % (P<0.01) for CD62P, and (5.24±2.22) mg/L vs. (9.20±1.93) mg/L (P<0.01) for TpP. The expression of PAC-1 was significantly different between the two subgroups on the first day, with values of (3.15±0.42)% vs. (5.30±.48)% (P<0.01). The Marshall score of the two groups showed similar changes. Correlation analysis showed that PAC-1, CD62P and TpP were significantly correlated with the Marshall score. Conclusions Platelet activation and microthrombosis existing in the early stage of severe sepsis work together in the early hypercoagulable state.They both play important roles in disease development and progression. The dynamic detection of CD62P and TpP is beneficial to the diagnosis and prognosis of severe sepsis.PAC-1 appears to hold a risk stratification effect, as pa-tients with high expression of PAC-1 in the early stage show poor prognosis. Therefore, PAC-1 could be used as a marker of severe sepsis and poor prognsis.
7.Experimental study on effect of airway pressure on cardiopulmonary resuscitation
Dingyu TAN ; Feng SUN ; Yangyang FU ; Shihuan SHAO ; Yazhi ZHANG ; Yingying HU ; Jun XU ; Huadong ZHU ; Xuezhong YU
Chinese Critical Care Medicine 2017;29(6):531-535
Objective To observe the effect of different airway pressure on ventilation, organ perfusion and return of spontaneous circulation (ROSC) of cardiac arrest (CA) pigs during cardiopulmonary resuscitation (CPR), and to explore the possible beneficial mechanism of positive airway pressure during CPR. Methods Twenty healthy landrace pigs of clean grade were divided into low airway pressure group (LP group, n = 10) and high airway pressure group (HP group, n = 10) with random number table. The model of ventricular fibrillation (VF) was reproduced by electrical stimulation, and mechanical chest compressions and mechanical ventilation (volume-controlled mode, tidal volume 7 mL/kg, frequency 10 times/min) were performed after 8 minutes of untreated VF. Positive end expiratory pressure (PEEP) in LP group and HP group was set to 0 cmH2O and 6 cmH2O (1 cmH2O = 0.098 kPa) respectively. Up to three times of 100 J biphasic defibrillation was delivered after 10 minutes of CPR. The ROSC of animals were observed, and the respiratory parameters, arterial and venous blood gas and hemodynamic parameters were recorded at baseline, 5 minutes and 10 minutes of CPR. Results The number of animals with ROSC in the HP group was significantly more than that in the LP group (8 vs. 3, P < 0.05). Intrathoracic pressure during chest compression relaxation was negative in the HP group, and its absolute value was significantly lower than that in LP group at the same time [intrathoracic negative pressure peak (cmH2O): -4.7±2.2 vs. -10.8±3.5 at 5 minutes, -3.9±2.8 vs. -6.5±3.4 at 10 minutes], however, there was significantly difference only at 5 minutes of CPR (P < 0.01). Intrathoracic pressure variation during CPR period in the HP group were significantly higher than those in the LP group (cmH2O: 22.5±7.9 vs. 14.2±4.4 at 5 minutes, 23.1±6.4 vs. 12.9±5.1 at 10 minutes, both P < 0.01). Compared to the LP group, arterial partial pressure of oxygen [PaO2 (mmHg, 1 mmHg = 0.133 kPa): 81.5±10.7 vs. 68.0±12.1], venous oxygen saturation (SvO2: 0.493±0.109 vs. 0.394±0.061) at 5 minutes of CPR, and PaO2 (mmHg: 77.5±13.4 vs. 63.3±10.5), arterial pH (7.28±0.09 vs 7.23±0.11), SvO2 (0.458±0.096 vs. 0.352±0.078), aortic blood pressure [AoP (mmHg): 39.7±9.5 vs. 34.0±6.9], coronary perfusion pressure [CPP (mmHg): 25.2±9.6 vs. 19.0±7.6], and carotid artery flow (mL/min:44±16 vs. 37±14) at 10 minutes of CPR in the HP group were significantly higher (all P < 0.05). Arterial partial pressure of carbon dioxide (PaCO2) in the HP group was significantly lower than that in the LP group at 10 minutes of CPR (mmHg: 60.1±9.7 vs. 67.8±8.6, P < 0.05). Conclusions Compared to low airway pressure, a certain degree of positive airway pressure can still maintain the negative intrathoracic pressure during relaxation of chest compressions of CPR, while increase the degree of intrathoracic pressure variation. Positive airway pressure can improve oxygenation and hemodynamics during CPR, and is helpful to ROSC.
8.Benefits and risks of stress ulcer prevention with proton pump inhibitors for critical patients: an observational cohort study with 1 972 patients
Jiayan SUN ; Bingxia WANG ; Peng CAO ; Hua ZHU ; Kangsheng LU ; Ping GENG ; Dingyu TAN
Chinese Critical Care Medicine 2019;31(5):539-544
Objective To investigate the benefits and risks of stress ulcer prevention (SUP) using proton pump inhibitors (PPI) for critical patients. Methods The clinical data of adult critically ill patients admitted to the intensive care unit (ICU) of Northern Jiangsu People's Hospital from January 2016 to December 2018 were retrospectively analyzed. All patients who were treated with PPI for SUP within the first 48 hours after ICU admission were enrolled in the SUP group. Those who not received PPI were enrolled in the control group. A one-to-one propensity score matching (PSM) was performed to control for potential biases. The gender, age, underlying diseases, main diagnosis of ICU, drug use before ICU admission, sequential organ failure score (SOFA) at ICU admission, risk factors of stress ulcer (SU) and PPI usage were recorded. The end point was the incidence of gastrointestinal bleeding, hospital acquired pneumonia, Clostridium difficile infection and 30-day mortality. Kaplan-Meier survival curves were plotted, and survival analysis was performed using the log-rank test. Results 1 972 critical patients (788 in the SUP group and 1 184 in the control group) were enrolled, and each group enrolled 358 patients after PSM. Prior to PSM, compared with the control group, the SUP group had older patients, more underlying diseases, higher proportion of acute coronary syndrome (ACS), acute cerebrovascular disease, acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and poisoning in main diagnosis of ICU, more serious illness, and more risk factors of SU, indicating that ICU physicians were more likely to prescribe SUP for these patients. The incidence of gastrointestinal bleeding in the SUP group was significantly lower than that in the control group [1.8% (14/788) vs. 3.7% (44/1 184), P < 0.05], while the incidence of hospital acquired pneumonia and 30-day mortality were significantly higher than those in the control group [6.6% (52/788) vs. 3.5% (42/1 184), 17.9% (141/788) vs. 13.1% (155/1 184), both P < 0.01]. There was no significant difference in the incidence of Clostridium difficile infection between the SUP group and the control group [2.9% (23/788) vs. 1.8% (21/1 184), P >0.05]. After the propensity scores for age, underlying diseases, severity of illness and SU risk factors were matched, there was no significant difference in the incidence of gastrointestinal bleeding or 30-day mortality between the SUP group and the control group [2.2% (8/358) vs. 3.4% (12/358), 15.9% (57/358) vs. 13.7% (49/358), both P > 0.05], but the incidence of hospital acquired pneumonia in the SUP group was still significantly higher than that in the control group [6.7% (24/358) vs. 3.1% (11/358), P < 0.05]. Kaplan-Meier survival curve analysis showed that the 30-day cumulative survival rate of the SUP group was significantly lower than that of the control group before the PSM (log-rank test: χ2 = 9.224, P = 0.002). There was no significant difference in the 30-day cumulative survival rate between the two groups after PSM (log-rank test: χ2 = 0.773, P = 0.379). Conclusion For critical patients, the use of PPI for SUP could not significantly reduce the incidence of gastrointestinal bleeding and mortality, but increase the risk of hospital acquired pneumonia.
9.High flow nasal cannula oxygen therapy versus non-invasive ventilation for chronic obstructive pulmonary diseases with acute-moderate hypercapnic respiratory failure: an observational cohort study
Dingyu TAN ; Bingyu LING ; Jiayan SUN ; Ping GENG ; Jun XU ; Huadong ZHU ; Xuezhong YU
Chinese Journal of Emergency Medicine 2018;27(4):361-366
Objective To compare the efficacy of high flow nasal cannula oxygen therapy (HFNC) and non-invasive ventilation (NIV) in the treatment of chronic obstructive pulmonary disease (COPD) with acute-moderate type Ⅱ respiratory failure,and to explore the feasibility of HFNC in the treatment of COPD with respiratory failure.Methods Patients diagnosed with COPD with acute moderate type Ⅱ respiratory failure (Arterial blood gas pH 7.25-7.35,PaCO2> 50 mmHg) admitted to the ICUs from April 2017 to December 2017 were retrospectively analyzed.All patients who were treated with HFNC within the first 4 hours after the admission to the ICUs,and continued for more than 2 hours and for at least 4 hours within the first 24 hours were included in the HFNC group.Those treated with NIV in the same conditions were included in the NIV group.The end point was the failure rates of treatment (changing to respiratory support method in another group or invasive ventilation) and 28-day mortality.Results Eighty-two patients (39 in the HFNC group and 43 in the NIV group) were enrolled.The HFNC group had a treatment failure rate of 28.2%,which was lower than that of the NIV group (39.5%).However,Kaplan-Meier curve analysis showed no significant difference between the two groups (Log Rank test 1.228,P=0.268).The 28-day mortality rate in HFNC group was 15.4%,which was no different from 14% in NIV group (Log Rank test 0.049,P=0.824).The number of airway care interventions within the first 24 hours was significantly lower in the HFNC group than in the NIV group [5 (3~8) vs.11 (7~15)],whereas the duration of respiratory support within the first 24 hours was significantly longer in the HFNC group than in the NIV group [16 (9~22) hours vs.8 (4~11) hours] (all P<0.05).The incidence of nasal facial lesions in the NIV group was 20.9%,significantly higher than that of HFNC group (5.1%,P <0.05).Conclusion For COPD with acute moderate type Ⅱ respiratory failure,HFNC has similar therapeutic effects as NIV.HFNC has better therapeutic tolerance and is a new potential respiratory support method for clinical treatment of COPD with respiratory failure.
10.Exploratory study on the application of nasal high-flow oxygen therapy during breaks off noninvasive ventilation for acute exacerbation of chronic obstructive pulmonary disease
Dingyu TAN ; Bingyu LING ; Yan XU ; Yunyun WANG ; Jun XU ; Bingxia WANG ; Peng CAO ; Xueqin SHAN ; Qingcheng ZHU ; Ping GENG
Chinese Journal of Emergency Medicine 2020;29(8):1046-1052
Objective:To compare the therapeutic effects of nasal high-flow oxygen therapy (HFNC) and nasal canal oxygenation (NCO) during breaks off non-invasive ventilation (NIV) for acute exacerbation of chronic obstructive pulmonary disease (AECOPD), and to explore the feasibility of NIV combined with HFNC in the treatment of AECOPD.Methods:From August 2017 to July 2019, AECOPD patients with type Ⅱrespiratory failure (arterial blood gas pH <7.35, PaCO 2 > 50 mmHg) who were treated with NIV were randomly (random number) assigned to the HFNC group and NCO group at 1:1. The HFNC group received HFNC treatment during breaks from NIV and the NCO group received low-flow NCO during the NIV interval. The primary endpoint was the total respiratory support time. The secondary endpoints were endotracheal intubation, duration of NIV treatment and breaks from NIV, length of ICU stay, total length of hospital stay and so on. Results:Eighty-two patients were randomly assigned to the HFNC group and the NCO group. After secondary exclusion, 36 patients in the HFNC group and 37 patients in the NCO group were included in the analysis. The total respiratory support time in the HFNC group was significantly shorter than that in the NCO group [(74 ± 18) h vs. (93 ± 20) h, P = 0.042]. The total duration of NIV treatment in the HFNC group was significantly shorter than that in the NCO group [(36 ± 11) h vs. (51 ± 13) h, P=0.014]. There was no significant difference of the mean duration of single break from NIV between the two groups, but durations of break from NIV in the HFNC group were significantly longer than those in the NCO group since the third break from NIV ( P < 0.05). The intubation rates of the HFNC and NCO groups were 13.9% and 18.9%, respectively, with no significant difference ( P=0.562). The length of ICU stay in the HFNC group was (4.3 ± 1.7) days, which was shorter than that in the NCO group [(5.8 ± 2.1) days, P=0.045], but there was no significant difference in the total length of hospital stay between the two groups. Heart rate, respiratory rate, percutaneous carbon dioxide partial pressure and dyspnea score during the breaks from NIV in the NCO group were significantly higher than those in the HFNC group, and the comfort score was lower than that in the HFNC group ( P<0.05). Conclusion:For AECOPD patients receiving NIV, compared with NCO, HFNC during breaks from NIV can shorten respiratory support time and length of ICU stay, and improve carbon dioxide retention and dyspnea. HFNC is an ideal complement to NIV therapy in AECOPD patients.