Remifentanil Versus Dexmedetomidine for Post-Cardiac Surgery Patients With Noninvasive Ventilation Intolerance: A Prospective, Observational,Cohort Study
Conditions: Cardiac Surgery
Sponsor: Shanghai Zhongshan Hospital

Remifentanil Versus Dexmedetomidine for Post-Cardiac Surgery Patients 
With Noninvasive Ventilation Intolerance (REDNIVIN) 
NCT：03395886 
Document date: December 15th, 2017 
Brief summary 
The aim of this study is to compare the sedation effects between 
remifentanil and dexmedetomidine in post-cardiac surgical patients who 
developed noninvasive ventilation (NIV) intolerance. 
Study description 
This study is a prospective, observational, cohort study. Data of post-
cardiac surgery patients who receives noninvasive ventilation (NIV) in the 
investigators' cardiac surgical intensive care unit are prospectively 
collected into a database for further analyzation since January 2018. 
Tolerance of NIV is estimated by a four-point NIV intolerance score system: 
A score of 1 indicates a comfortable and relaxed patient tolerating NIV; a 
score of 2 indicates mild intolerance with some discomfort and occasional 
grabbing at the NIV mask; a score of 3 indicates moderate intolerance and 
discomfort with the NIV mask most of the time with frequent grabbing at 
the mask (sometimes pulling it off); and a score of 4 indicates severe NIV 
intolerance with agitation or/and an inability to leave the NIV mask in 
place. Participants who receives re-intubation will be recorded as 4 points. 
Application of remifentanil or dexmedetomidine will be initiated when a 

score of 3 or 4 was recorded, according to the intensivists’ preference. 
Depending on the sedation regime applied, patients with NIV intolerance 
are divided into two groups: remifentanil group and dexmedetomidine 
group. The investigators will compare the two groups with the NIV 
intolerance score at 15min,1, 3, 6, 12, 24, 48, 60 and 72 hours after the 
initiation of the sedation regime. The investigators will also compare the 
two groups with clinical outcomes such as NIV failure, tracheotomy rate, 
in-hospital mortality, ICU length of stay etc. 
Inclusion criteria 
(1) Adult 
(2) Cardiac surgery 
(3) NIV intolerance 
Exclusion criteria 
(1) difficult expectoration;  
(2) maternal; 
(3) severe hemodynamic instability defined by mean arterial pressure 
lower than 60 mmHg despite fluid optimization and vasoactive drugs. 
NIV support 
NIV will be performed via a facial mask (ZS-MZ-A; Shanghai Zhongshan 
Medical Technology, China) connected to Drager ventilator (Drager, 
Lubeck, Germany) in pressure support mode (PSV). NIV will be started 
with fractional inspired oxygen of 100% and level of pressure support of 

12 cm H2O. The ventilator settings will be then adjusted according to the 
patient’s vital signs, tolerance, and/or arterial blood gas (ABG) 
measurements. 
Sedation  
Remifentanil will be started with 0.05 μg/kg/min, while dexmedetomidine 
will be started with 0.5 μg/kg/h. The doses will then be adjusted according 
to the sedation satisfaction (sedation target is to achieve NIV intolerant 
score 1-2), with the maximum dose to be 0.12 μg/kg/min for remifentanil 
and 1.0 μg/kg/h for dexmedetomidine.  
Statistical plan 
Summary statistics are expressed as the mean ± standard deviation, the 
median and interquartile ranges (25th to 75th percentile), or number and 
percentage, and compared between groups using the Student’s t-test, 
Wilcoxon rank-sum test, or Fisher's exact test, as appropriate. A percentage 
stacked area chart of patient status will be constructed after administration 
of both drugs. The generalized estimating equations approach will be 
employed to analyze changes in the mitigation rate over time between the 
two groups. Statistical analysis will be performed using R, version 3.6.0 (R 
Foundation for Statistical Computing, Vienna, Austria) 
Outcomes measures 
The primary outcome of this study is NIV failure defined as reintubation 
or death in this 72-hour course of study between the two groups. The 

secondary outcome is rate of mitigation defined by patients who is relieved 
from the initial NIV intolerant status.