Objective To explore the impact of neurally adjusted ventilatory assist(NAVA)mode on the weaning outcomes of patients with severe cerebrovascular disease who have weaning difficulty from mechanical ventilation.Methods Patients with severe cerebrovascular disease who had weaning difficulty from mechanical ventilation and were admitted to the Intensive Care Unit(ICU)of Neurosurgery Departement,the First Affiliated Hospital of Wannan Medical College(Yijishan Hospital of Wannan Medical College)from November 2019 to November 2021 were prospectively and consecutively included.They were randomly divided into the NAVA group and the pressure support ventilation(PSV)group using a random number table,with 28 patients in each group.Baseline and clinical data of the two groups were collected,including gender,age,main diagnosis,past medical history(hypertension,stroke,respiratory diseases,diabetes,coronary heart disease),body mass index,acute physiology and chronic health evaluation(APACHE)Ⅱ score,Glasgow coma scale(GCS)score,types of difficult weaning(failure of the first spontaneous breathing trial[SBT],re-intubation within 48 h after the first weaning attempt),and mechanical ventilation time before randomization.SBT and weaning-related indicators after randomization were collected,including respiratory mechanics and parameters before SBT implementation after randomization(peak airway pressure,expiratory tidal volume,positive end-expiratory pressure,inspired oxygen concentration,minute ventilation,mean airway pressure,diaphragmatic electrical activity signal value,neural ventilation efficiency,neural mechanical efficiency),basic vital signs(mean arterial pressure,respiratory heart rate)before weaning after passing SBT,blood routine(white blood cells,hemoglobin)and biochemical tests(albumin,creatinine,troponin,B-type natriuretic peptide)within 48 h before weaning,and arterial blood gas within 30 min before weaning(pH,partial pressure of carbon dioxide,partial pressure of oxygen,bicarbonate ion,oxygenation index).The primary outcome measures included the time required for successful weaning from randomization to day 28(if the patient died or failed to wean successfully before day 28 after randomization,the time required for weaning was defined as 28 d),total mechanical ventilation time after randomization,total weaning success rate from randomization to day 28,total weaning-free time at 7,14,and 28 d after randomization,survival time at 28 d and 90 d after randomization,ICU length of stay,total hospital length of stay,and cumulative weaning success rate from randomization to day 28 in both groups.The secondary outcome measures included tracheotomy rate after randomization,ICU mortality rate,mortality rate at 28 d and 90 d after randomization,incidence of mechanical ventilation-related complications(ventilator-associated pneumonia,acute respiratory distress syndrome,pneumothorax,pleural effusion)during mechanical ventilation after randomization,and cumulative survival rate at 90 d after randomization.The human-machine coordination within 24 h after randomization was recorded in both groups including the number and index of ineffective triggering,false triggering,double triggering,premature switching from inspiration to expiration,delayed switching from inspiration to expiration,and triggering delay,as well as the total asynchrony index,with one record every 8 h,each record lasting for 1 min,for a total of 3 min.Results A total of 56 patients with severe cerebrovascular disease who had weaning difficulty from mechanical ventilation were included,with 28 patients in each of the PSV group and the NAVA group.There were no statistically significant differences between the two groups in terms of gender,age,main diagnosis,past medical history,body mass index,APACHE Ⅱ score,GCS score,types of difficult weaning,mechanical ventilation time before randomization,indicators before SBT implementation after randomization and after SBT before weaning(all P＞0.05).(1)The time required for successful weaning from randomization to day 28(9.00[7.00,15.50]d vs.15.50[10.25,22.75]d)and total mechanical ventilation time after randomization(8.50[7.00,12.75]d vs.13.50[10.00,20.00]d)were both lower in the NAVA group than those in the PSV group(all P＜0.05).The cumulative weaning success rate of the NAVA group was higher than that of the PSV group at 28 d after randomization(P=0.039),but there was no statistically significant difference in the total weaning success rate between the two groups from randomization to the day 28(92.9％[26/28]vs.85.7％[24/28],P=0.669).The NAVA group had longer periods without mechanical ventilation within 14 d(5.00[0.00,7.00]d vs.0.00[0.00,3.75]d)and within 28 d(18.00[9.25,20.75]d vs.10.50[0.25,17.75]d)after randomization compared with the PSV group(all P＜0.05),but there was no statistically significant difference in the period without mechanical ventilation within 7 d after randomization between the two groups(P=0.159).The ICU stay of the NAVA group was shorter than that of the PSV group(9.00[6.25,16.75]d vs.14.00[10.25,22.50]d,P=0.015),but there were no statistically significant difference in the total hospital stay and survival time within 28 d and 90 d after randomization between the two groups(all P＞0.05).(2)There was no statistically significant difference between the two groups in tracheotomy rate,ICU mortality rate,mortality rate at 28 d and 90 d after randomization,complications during mechanical ventilation after randomization,and cumulative survival rate at 90 d after randomization(all P＞0.05).(3)In terms of human-machine coordination,the NAVA group had lower frequencies and indices of false triggering(frequency:0.00[0.00,0.00]time/min vs.0.00[0.00,0.58]time/min;index:0.00[0.00,0.00]vs.0.00[0.00,0.02]),ineffective triggering(frequency:0.00[0.00,0.33]time/min vs.1.00[0.33,2.17]time/min;index:0.00[0.00,0.02]vs.0.05[0.02,0.09]),premature switching(frequency:0.00[0.00,0.33]time/min vs.0.33[0.33,1.00]time/min;index:0.00[0.00,0.01]vs.0.02[0.02,0.05]),delayed switching(frequency:0.00[0.00,0.00]time/min rs.1.17[0.00,5.67]time/min;index:0.00[0.00,0.00]rs.0.06[0.00,0.29]),and delayed triggering(frequency:0.00[0.00,0.58]time/min vs.0.67[0.33,1.67]time/min;index:0.00[0.00,0.02]vs.0.05[0.02,0.10])compared with the PSV group(all P＜0.01).The NAVA group had higher frequencies and indices of double triggering(frequency:1.17[0.33,2.00]time/min vs.0.00[0.00,0.00]time/min;index:0.06[0.02,0.11]vs.0.00[0.00,0.00];all P＜0.01),but the total asynchrony index of the NAVA group was lower than that of the PSV group(0.08[0.04,0.14]vs.0.24[0.19,0.51],P＜0.01).Conclusion The NAVA mode can shorten the weaning and mechanical ventilation time of patients with severe cerebrovascular disease who have weaning difficulty from mechanical ventilation,improve human-machine coordination,and has potential advantages in increasing the weaning success rate.

Objective To explore the impact of neurally adjusted ventilatory assist(NAVA)mode on the weaning outcomes of patients with severe cerebrovascular disease who have weaning difficulty from mechanical ventilation.Methods Patients with severe cerebrovascular disease who had weaning difficulty from mechanical ventilation and were admitted to the Intensive Care Unit(ICU)of Neurosurgery Departement,the First Affiliated Hospital of Wannan Medical College(Yijishan Hospital of Wannan Medical College)from November 2019 to November 2021 were prospectively and consecutively included.They were randomly divided into the NAVA group and the pressure support ventilation(PSV)group using a random number table,with 28 patients in each group.Baseline and clinical data of the two groups were collected,including gender,age,main diagnosis,past medical history(hypertension,stroke,respiratory diseases,diabetes,coronary heart disease),body mass index,acute physiology and chronic health evaluation(APACHE)Ⅱ score,Glasgow coma scale(GCS)score,types of difficult weaning(failure of the first spontaneous breathing trial[SBT],re-intubation within 48 h after the first weaning attempt),and mechanical ventilation time before randomization.SBT and weaning-related indicators after randomization were collected,including respiratory mechanics and parameters before SBT implementation after randomization(peak airway pressure,expiratory tidal volume,positive end-expiratory pressure,inspired oxygen concentration,minute ventilation,mean airway pressure,diaphragmatic electrical activity signal value,neural ventilation efficiency,neural mechanical efficiency),basic vital signs(mean arterial pressure,respiratory heart rate)before weaning after passing SBT,blood routine(white blood cells,hemoglobin)and biochemical tests(albumin,creatinine,troponin,B-type natriuretic peptide)within 48 h before weaning,and arterial blood gas within 30 min before weaning(pH,partial pressure of carbon dioxide,partial pressure of oxygen,bicarbonate ion,oxygenation index).The primary outcome measures included the time required for successful weaning from randomization to day 28(if the patient died or failed to wean successfully before day 28 after randomization,the time required for weaning was defined as 28 d),total mechanical ventilation time after randomization,total weaning success rate from randomization to day 28,total weaning-free time at 7,14,and 28 d after randomization,survival time at 28 d and 90 d after randomization,ICU length of stay,total hospital length of stay,and cumulative weaning success rate from randomization to day 28 in both groups.The secondary outcome measures included tracheotomy rate after randomization,ICU mortality rate,mortality rate at 28 d and 90 d after randomization,incidence of mechanical ventilation-related complications(ventilator-associated pneumonia,acute respiratory distress syndrome,pneumothorax,pleural effusion)during mechanical ventilation after randomization,and cumulative survival rate at 90 d after randomization.The human-machine coordination within 24 h after randomization was recorded in both groups including the number and index of ineffective triggering,false triggering,double triggering,premature switching from inspiration to expiration,delayed switching from inspiration to expiration,and triggering delay,as well as the total asynchrony index,with one record every 8 h,each record lasting for 1 min,for a total of 3 min.Results A total of 56 patients with severe cerebrovascular disease who had weaning difficulty from mechanical ventilation were included,with 28 patients in each of the PSV group and the NAVA group.There were no statistically significant differences between the two groups in terms of gender,age,main diagnosis,past medical history,body mass index,APACHE Ⅱ score,GCS score,types of difficult weaning,mechanical ventilation time before randomization,indicators before SBT implementation after randomization and after SBT before weaning(all P＞0.05).(1)The time required for successful weaning from randomization to day 28(9.00[7.00,15.50]d vs.15.50[10.25,22.75]d)and total mechanical ventilation time after randomization(8.50[7.00,12.75]d vs.13.50[10.00,20.00]d)were both lower in the NAVA group than those in the PSV group(all P＜0.05).The cumulative weaning success rate of the NAVA group was higher than that of the PSV group at 28 d after randomization(P=0.039),but there was no statistically significant difference in the total weaning success rate between the two groups from randomization to the day 28(92.9％[26/28]vs.85.7％[24/28],P=0.669).The NAVA group had longer periods without mechanical ventilation within 14 d(5.00[0.00,7.00]d vs.0.00[0.00,3.75]d)and within 28 d(18.00[9.25,20.75]d vs.10.50[0.25,17.75]d)after randomization compared with the PSV group(all P＜0.05),but there was no statistically significant difference in the period without mechanical ventilation within 7 d after randomization between the two groups(P=0.159).The ICU stay of the NAVA group was shorter than that of the PSV group(9.00[6.25,16.75]d vs.14.00[10.25,22.50]d,P=0.015),but there were no statistically significant difference in the total hospital stay and survival time within 28 d and 90 d after randomization between the two groups(all P＞0.05).(2)There was no statistically significant difference between the two groups in tracheotomy rate,ICU mortality rate,mortality rate at 28 d and 90 d after randomization,complications during mechanical ventilation after randomization,and cumulative survival rate at 90 d after randomization(all P＞0.05).(3)In terms of human-machine coordination,the NAVA group had lower frequencies and indices of false triggering(frequency:0.00[0.00,0.00]time/min vs.0.00[0.00,0.58]time/min;index:0.00[0.00,0.00]vs.0.00[0.00,0.02]),ineffective triggering(frequency:0.00[0.00,0.33]time/min vs.1.00[0.33,2.17]time/min;index:0.00[0.00,0.02]vs.0.05[0.02,0.09]),premature switching(frequency:0.00[0.00,0.33]time/min vs.0.33[0.33,1.00]time/min;index:0.00[0.00,0.01]vs.0.02[0.02,0.05]),delayed switching(frequency:0.00[0.00,0.00]time/min rs.1.17[0.00,5.67]time/min;index:0.00[0.00,0.00]rs.0.06[0.00,0.29]),and delayed triggering(frequency:0.00[0.00,0.58]time/min vs.0.67[0.33,1.67]time/min;index:0.00[0.00,0.02]vs.0.05[0.02,0.10])compared with the PSV group(all P＜0.01).The NAVA group had higher frequencies and indices of double triggering(frequency:1.17[0.33,2.00]time/min vs.0.00[0.00,0.00]time/min;index:0.06[0.02,0.11]vs.0.00[0.00,0.00];all P＜0.01),but the total asynchrony index of the NAVA group was lower than that of the PSV group(0.08[0.04,0.14]vs.0.24[0.19,0.51],P＜0.01).Conclusion The NAVA mode can shorten the weaning and mechanical ventilation time of patients with severe cerebrovascular disease who have weaning difficulty from mechanical ventilation,improve human-machine coordination,and has potential advantages in increasing the weaning success rate.

Objective:To explore the prognostic effect and safety of neurally adjusted ventilatory assist (NAVA) mode on the patients with severe neurological cerebrovascular disease undergoing mechanical ventilation.Methods:A prospective study was conducted. Fifty-four patients with cerebrovascular disease undergoing mechanical ventilation admitted to the neurosurgery intensive care unit (NSICU) of the First Affiliated Hospital of Wannan Medical College (Yijishan Hospital) from December 2020 to May 2022 were enrolled. They were divided into NAVA group and pressure support ventilation (PSV) group by computer random number generator with 27 patients in each group. The ventilation time of the two groups was ≥72 hours. The general basic data of the two groups were recorded. The time without mechanical ventilation 28 days after enrollment, total length of mechanical ventilation, survival rate of 90 days after enrollment, length of NSICU stay, total length of hospital stay, NSICU mortality, in-hospital mortality, Glasgow outcome score (GOS), complications related to mechanical ventilation, and changes of respiratory mechanics indexes, arterial blood gases, vital signs, and diaphragm function indexes were observed.Results:The time without mechanical ventilation 28 days after enrollment in the NAVA group was significantly longer than that in the PSV group [days: 22 (15, 26) vs. 6 (0, 23), P < 0.05]. However, there were no significant differences in the total length of mechanical ventilation, 90-day survival rate, length of NSICU stay, total length of hospital stay, NSICU mortality, in-hospital mortality, GOS score, and incidence of mechanical ventilator-related complications between the two groups. In terms of respiratory mechanics parameters, the expiratory tidal volume (VTe) on 3 days after mechanical ventilation of patients in the NAVA group was significantly lower than that on 1 day and 2 days, and significantly lower than that in the PSV group [mL: 411.0 (385.2, 492.6) vs. 489.0 (451.8, 529.4), P < 0.01]. Minute ventilation (MV) at 2 days and 3 days in the NAVA group was significantly higher than that at 1 day, and significantly higher than that in the PSV group at 2 days [L/min: 9.8 (8.4, 10.9) vs. 7.8 (6.5, 9.8), P < 0.01], while there was no significant change of MV in the PSV group. At 1 day, peak airway pressure (Ppeak) and mean airway pressure (Pmean) in the NAVA group were significantly lower than those in the PSV group [Ppeak (cmH 2O, 1 cmH 2O≈0.098 kPa): 14.0 (12.2, 17.0) vs. 16.6 (15.0, 17.4), Pmean (cmH 2O): 7.0 (6.2, 7.9) vs. 8.0 (7.0, 8.2), both P < 0.05]. However, there was no significant difference in the Ppeak or Pmean at 2 days and 3 days between the two groups. In terms of arterial blood gas, there was no significant difference in pH value between the two groups, but with the extension of mechanical ventilation time, the pH value at 3 days of the two groups was significantly higher than that at 1 day. Arterial partial pressure of oxygen (PaO 2) at 1 day in the NAVA group was significantly lower than that in the PSV group [mmHg (1 mmHg≈0.133 kPa): 122.01±37.77 vs. 144.10±40.39, P < 0.05], but there was no significant difference in PaO 2 at 2 days and 3 days between the two groups. There was no significant difference in arterial partial pressure of carbon dioxide (PaCO 2) or oxygenation index (PaO 2/FiO 2) between the two groups. In terms of vital signs, the respiratory rate (RR) at 1, 2, and 3 days of the NAVA group was significantly higher than that of the PSV group [times/min: 19.2 (16.0, 25.2) vs. 15.0 (14.4, 17.0) at 1 day, 21.4 (16.4, 26.0) vs. 15.8 (14.0, 18.6) at 2 days, 20.6 (17.0, 23.0) vs. 16.7 (15.0, 19.0) at 3 days, all P < 0.01]. In terms of diaphragm function, end-inspiratory diaphragm thickness (DTei) at 3 days in the NAVA group was significantly higher than that in the PSV group [cm: 0.26 (0.22, 0.29) vs. 0.22 (0.19, 0.26), P < 0.05]. There was no significant difference in end-expiratory diaphragm thickness (DTee) between the two groups. The diaphragm thickening fraction (DTF) at 2 days and 3 days in the NAVA group was significantly higher than that in the PSV group [(35.18±12.09)% vs. (26.88±8.33)% at 2 days, (35.54±13.40)% vs. (24.39±9.16)% at 3 days, both P < 0.05]. Conclusions:NAVA mode can be applied in patients with neuro-severe cerebrovascular disease, which can prolong the time without mechanical ventilation support and make patients obtain better lung protective ventilation. At the same time, it has certain advantages in avoiding ventilator-associated diaphragm dysfunction and improving diaphragm function.