Effect of Deep Versus Moderate Neuromuscular Blockade on Peak Airway Pressures During Elective Laparoscopic Surgery
Phase: PHASE4
Conditions: Cholecystitis, Endometriosis, Bowel Obstruction, Fibroids, Prostate Cancer, Chronic Kidney Disease, Uterine Prolapse
Sponsor: Stony Brook University

Protocol version 5 – April 5, 2018 
 
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Effect of Deep versus Moderate Neuromuscular Blockade on Peak 
Airway Pressures During Elective Laparoscopic Surgery 
NCT02812186 
 
Background 
The frequency of surgical procedures that can be performed laparoscopically is rapidly 
increasing.  Surgical conditions in laparoscopic surgery are largely determined by the depth of 
neuromuscular relaxation during surgery.  Neuromuscular blockade (NMB) is frequently utilized 
in laparoscopic procedures to improve surgical conditions1 by relaxing the abdominal muscles and 
thus facilitating insufflation with CO2 to optimize surgical view.  While studies have investigated 
the effects of neuromuscular blockade on surgical conditions and abdominal insufflation pressures, 
to our knowledge, little is known about the benefit, if any, a deep NMB blockade will have over a 
moderate NMB on airway pressures.  Increased airway pressures can lead to an increase in alveolar 
and perivascular edema, a decline in dynamic lung compliance and hypoxemia. 16 A deep 
neuromuscular blockade could decrease the resistance to ventilation by increasing the compliance 
of the chest and abdominal wall, thereby allowing maximization of lung expansion at lower airway 
pressures.   
Several studies have investigated surgical view under deep vs. moderate neuromuscular blockade. 
Across a single intraabdominal insufflation pressure, a deep neuromuscular blockade may provide 
better surgical conditions than a moderate block6, 8-11.    Raising the intraabdominal insufflation 
pressure can result in several adverse outcomes such as increased airway pressures, postoperative 
pain, risk of CO2 embolism, and hemodynamic disturbances15.  Low insufflation pressures of < 12 
mm Hg have been associated with fewer adverse effects than higher pressures (>15 mm Hg)7. 
Though studies have shown that surgical view under deep block is statistically superior to the view 
under a moderate NMB block across a single insufflation pressure 6,8-11,  the primary outcome in 
these studies was a subjective, 5 point scale requiring the surgeon to grade his surgical view. 
Hence, there is a lack of objective outcomes assessed in these studies.   Measuring the peak airway 
pressures in the deep vs. moderate block group will provide us with an objective indice to use in 
making the determination if one type of block is ‘superior’ to the other. 
Additionally, the degree of neuromuscular block for optimal surgical procedures has been the 
focus of debate and research for several years.  Firstly, different muscle groups have different 
sensitivity to neuromuscular blocking agents (NMBA). For example, though neuromuscular 
blockade is often measured at the adductor pollicis muscle in the thumb, the abdominal muscles 
and diaphragm are less sensitive to NMBA.2,3 Consequently, surgeons may complain of 
insufficient NMB though the anesthesiologist observes no twitches at the thumb. Thus, some 
authors have argued that paralysis of the diaphragm and the abdominal wall muscles can only be 

Protocol version 5 – April 5, 2018 
 
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ensured 
by 
an 
intense 
NMB, 
quantified 
by 
post-tetanic 
count 
(PTC) 
of 
1.4 
However, these results must be counterbalanced by the need for optimal extubating conditions 
which cannot occur unless there is full reversal of muscle paralysis, a condition which requires the 
presence of at least 1-2 twitches (if one uses the traditional drug, neostigmine, to antagonize 
paralysis which would not needed if we use the newly FDA approved drug, sugammadex).  Thus, 
a deep block throughout the procedure carries the inherent risk of delaying extubation if 
sugammadex is not available. 
The Table below shows known and theoretical risks/benefits related to deep vs medium NMB. 
Deep NMB 
Medium NMB 
Literature 
supports 
better 
operating 
conditions/view by surgeon 
Literature 
supports 
worse 
operating 
conditions/view by surgeon 
Possibly lower  airway pressures 
Possibly worse airway pressures 
Possibly longer duration to extubation 
Possibly shorter duration to extubation 
Possibly worse respiratory mechanics at the 
end of anesthesia 
Possibly better respiratory mechanics at the 
end of anesthesia 
 
Thus, there is clearly equipoise with regard to the comparative effectiveness of deep vs medium 
NMB.  Therefore, we wish to ascertain if a deep neuromuscular block will decrease the airway 
pressures in patients undergoing laparoscopic procedures compared to those under a moderate 
block.  A reduction in airway pressures may lead to a decrease in the complications associated 
with elevated airway pressures including hypoxemia, total static lung compliance, alveolar edema, 
and long term morbidity16.  Additionally, we wish to understand if time from administration of 
sugammadex to reversal is different between patients that have a moderate NMB as compared to 
a deep NMB.  
To test our hypotheses, we will conduct a two period cross-over study by randomizing patients 
undergoing laparoscopic surgery into 2 different groups: group 1 in which patients will receive 
“deep neuromuscular blockade” in the beginning portion of the surgery followed by a period of 
“moderate blockade”, and group 2 in which patients will receive “moderate neuromuscular 
blockade” in the beginning portion of the surgery followed by a period of “deep blockade”.  The 
deep neuromuscular block will be defined as post tetanic count of 0 to 2 and the moderate 
neuromuscular block will be defined as 1-2 twitches.  In all patients, sugammadex will be used to 
reverse the block at the end of surgery in order to obtain optimal extubating conditions.  Time from 
administration of sugammadex to extubation will be calculated and compared.  
Hypothesis 
A deep neuromuscular blockade results in lower peak airway pressures and lower abdominal 
insufflation pressures in patients undergoing elective laparoscopic procedures.   
 

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Objectives 
Primary Outcome:  Peak Airway Pressures  
Secondary outcomes:  
 Hemodynamics (blood pressure (BP), Heart rate (HR)) measured q15 min at the time of 
airway pressure measurement 
 Duration from administration of sugammadex (to be given at skin closure) to Train of Four 
(TOF) ratio = 0.7, 0.8 and 0.9 and extubation using the following guidelines (SpO2 >98% 
on 100% FiO2, Respiratory rate (RR) <35, tidal volume (TV) > 5 ml/kg, RR/Tidal Volume 
<100) 
 Recovery variables in the post-anesthesia care unit (respiratory rate, arterial oxygen 
saturation, numerical pain rating, nausea or vomiting, and level of sedation or alertness).  
 Adverse events (AE). 
 
Methods  
This will be a single-center, prospective, randomized, two-period crossover controlled trial. 
Approval from the local IRB will sought and patients will provide written informed consent. 
Inclusion and exclusion criteria 
Inclusion criteria:  
The participant must fulfill ALL the criteria listed below for entry. 
 Each participant must be willing and able to provide written informed consent for the study. 
 Each participant must be greater than or equal to 18 years of age. 
 Each participant must be ASA class I, II or III. 
 Each participant must be scheduled for elective laparoscopic surgery (this includes robotic 
laparoscopic s). 
 Expected surgical duration of 60 min or longer 
Exclusion criteria:  
 Inability to give informed oral or written consent 
 Known or suspected neuromuscular disorders impairing neuromuscular function;  
 True allergies as defined as hypotension, bronchospasm, or anaphylaxis to muscle 
relaxants, anesthetics or opioids 
 A history (patient or family) of malignant hyperthermia 
 A contraindication for neostigmine administration 
 Renal insufficiency, as defined by serum creatinine levels at 2.5 fold the normal level 
 Body mass index >45 kg/m 
 Significant respiratory disease. 
 Planned postoperative mechanical ventilation 

Protocol version 5 – April 5, 2018 
 
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Investigational plan and treatments (see Figure 1) 
 
Subjects will be randomly assigned to one of two study groups using a random number generator 
and sealed envelope technique:  
 
Group 1 DM: After induction and intubation, the patient will be maintained in a “deep” (post-
tetanic count of zero to two) neuromuscular block (NMB).  Deep NMB will be obtained with an 
intubating dose of rocuronium of 0.5 mg/kg or as per clinical team’s discretion. After surgical 
incision is made, the abdomen is insufflated, trocars are inserted, and prior to the beginning of the 
actual laparoscopic procedure, collection of data for “deep” NMB period will begin. 
Neuromuscular blockade level will be maintained and adjusted throughout the course of surgery 
using intravenous bolus doses of rocuronium. Dosing of rocuronium will be determined by the 
clinical team.  Only the clinical team will administer any medications or fluids to patients enrolled 
in the study (no research team members will be administering drug or fluid). The surgeon will 
inform the study team member of the first Surgical Rating Scale (SRS) score for his/her view, and 
simultaneously, the first peak airway pressure and related variables will be collected (T0). For the 
next 20 minutes of surgery during which a “deep” NMB is being maintained, peak airway pressure, 
heart rate, and blood pressure will be collected every minute by the study team member (as per the 
anesthesia machine’s readings), and the surgeon will provide the SRS score every 5 minutes.  
To minimize any type of carry-over effects, after the completion of the deep NMB 20 minute 
period, a “transition period” will begin (T1).     
 
Upon successful acclimation to a “moderate” NMB, data collection may begin again (T2): the 
surgeon will again provide the SRS score simultaneously with the commencement of collection 
for peak airway pressure and related values.  For the next 20 minutes of surgery during which a 
“moderate” NMB is maintained, peak airway pressure measurements (as well as other relevant 
secondary outcome measurements) will be collected every minute by the study team member by 
looking at the anesthesia machine’s readings and the surgeon will provide the SRS score every 5 
minutes.  After 20 minutes (T3), the patient will remain at the “moderate” NMB for the duration 
of the surgery unless a change in the depth of blockade is requested by the surgeon. Should such a 
request be made, this will be documented in the data collection (obtained from anesthesia record) 
along with the depth of blockade that the patient was switched to. By skin closure, the patient’s 
NMB will be returned to “moderate.”        
 
Group 2 MD:  After induction and intubation, the patient will be maintained in a “moderate” 
(one or two twitches) neuromuscular block (NMB). Moderate NMB will be obtained with 
intubating dose of rocuronium of 0.5 mg/kg or as per clinical team’s discretion. After surgical 
incision is made, the abdomen is insufflated, trocars are inserted and prior to the beginning of the 
actual laparoscopic procedure, collection of data for “moderate” NMB period will begin. 
Neuromuscular blockade level will be maintained and adjusted throughout the course of surgery 

Protocol version 5 – April 5, 2018 
 
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using intravenous bolus doses of rocuronium. Dosing of rocuronium will be determined by the 
clinical team.  Only the clinical team will administer any medications or fluids to patients enrolled 
in the study (no research team members will be administering drug or fluid). The surgeon will 
inform the study team member of the first SRS score for his/her view, and simultaneously,   the 
initial peak airway pressure and related values are collected (T0).  For the next 20 minutes of 
surgery (during which a “moderate” NMB is being maintained), peak airway pressure 
measurements, heart rate, and blood pressure will be collected every minute by the study team 
member by looking at the anesthesia machine’s readings, and the surgeon will provide the SRS 
score every 5 minutes.  
 
To minimize any type of carry-over effects, after completion of the moderate NMB 20 minute 
period, a “transition period” will begin (T1).  During this “transition period” additional IV bolus 
doses of rocuronium will be administered to the patient to achieve “deep” neuromuscular blockade. 
Upon successful acclimation to a “deep” NMB, data collection may begin again (T2): the surgeon 
will again provide the SRS score simultaneously with the commencement of collection for peak 
airway pressure and related values.  For the next 20 minutes of surgery (during which a “deep” 
NMB is maintained), peak airway pressure measurements (as well as other relevant secondary 
outcome measurements) will be collected every minute by the study team member by looking at 
the anesthesia machine’s readings, and the surgeon will provide the SRS score every 5 minutes.  
After 20 minutes (T3), the patient’s “deep” NMB will be maintained for the duration of the surgery 
unless a change in the depth of blockade is requested by the surgeon.  Should such a request be 
made, this will be documented in the data collection (obtained from the anesthesia record) along 
with the depth of blockade that the patient was switched to.  By skin closure, the patient’s depth 
will be returned to “deep.”        
 
(Both Group 1 and Group 2): At skin closure, subjects in both groups will be reversed with 
sugammadex 4 mg/kg or at the discretion of the clinical team (T4). Patients will be extubated when 
the TOF ratio becomes 0.9 or higher (T5).  Time from administration of sugammadex to extubation 
will be recorded. 
 
In the recovery room (T6), the following variables will be measured by the study coordinator at 15 
min intervals for the first 1 hour: respiratory rate, arterial oxygen saturation, numerical pain rating 
(on a scale from 0, no pain, to 10, most severe pain imaginable), occurrence of nausea or vomiting, 
and level of sedation or alertness. Additionally, the patient’s maximum inspired volume will be 
assessed 30 minutes after arrival in the PACU via the use of an incentive spirometer. After one 
hour, all measurements will be complete (T7).  
Intraoperative and postoperative data will be collected by a research coordinator who is not blinded 
to the patient’s randomization. The research coordinator will not be directly involved with the 
patient’s care.  Rather, his/her sole purpose will be to record the relevant data (airway pressures, 
abdominal insufflation pressures, PACU indices etc.) every 1 minute. The coordinator will have 

Protocol version 5 – April 5, 2018 
 
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access to the electronically recorded patient data and will make their recordings directly from the 
anesthesia machine and/or the electronic anesthesia record. The research coordinator will also 
review data from the patient’s chart (anesthesia record, PACU record) after surgery to collect any 
additional information that may be necessary.   
 
Anesthetic Technique 
 
Before administering any medications a baseline inspired volume via an incentive spirometer in 
the holding area will be obtained.  The type of anesthesia (general endotracheal) will be consistent 
with standard practice at Stony Brook and many other centers.  Induction of general anesthesia 
will be achieved by an induction agent such as propofol [1 to 2.5 mg/kg (lean body mass)] 
combined with bolus doses of fentanyl. Should a rapid sequence induction be desired based on the 
patient’s co-morbid conditions (reflux disease, etc.), succinylcholine or rocuronium may be used 
to obtain paralysis for intubation.  In the event that succinylcholine is used, the patient will be 
allowed to obtain a full return of muscle strength (TOF 4/4), prior to administration of rocuronium 
for further paralysis during the surgery.  Induction drugs and dosing may be modified at the 
discretion of the clinical anesthesia team. Maintenance of anesthesia will be achieved either 
through the use of volatile inhaled agents or intravenous anesthetic.  The choice of agents for 
maintenance will be based upon the discretion of the anesthesiologist.     
 
Neuromuscular monitoring 
 
Neuromuscular monitoring is standard of care for general endotracheal anesthesia. In this study 
neuromuscular function will be monitored using the TOF-watch SX acceleromyograph (MSD BV, 
Haarlem, The Netherlands) at the adductor pollicis muscle. The thumb is attached to a flexible 
adaptor that applies a constant preload to the thumb. Neuromuscular stimulation will be applied to 
the ulnar nerve via two pediatric electrodes applied on the skin left and right of the ulnar nerve at 
the distal forearm. Before administration of any neuromuscular blocking agent, but after induction 
of general anesthesia, the following procedures will be conducted to standardize the neuromuscular 
monitoring: (1) application of a tetanic ulnar nerve stimulation (50 Hz for 5 seconds); (2) 
calibration of the TOF-watch (CAL 2); (3) performance of a series of TOF measurements, to 
ensure that the TOF ratio differs by less than 5% between measurements (if the TOF ratio differs 
by more than 5%, the TOF-watch will be recalibrated). After these steps, the neuromuscular 
blocking agent according to protocol is administered. In patients requiring rapid sequence 
induction, succinylcholine will be used for intubation and after return of 4/4 twitches, the 
aforementioned steps (steps 1-3) will be conducted.  When, during the study, the number of 
measured twitches is zero, the PTC will be measured. A 50 Hz tetanic stimulation for 5 s is 
followed (after a 3 s rest) by 15 single stimulations at 1 Hz. The number of twitches generated 
(that is, the PTC) corresponds with the degree of NMB, with a PTC of 1 to 2 reflecting a deep 
level of NMB. 

Protocol version 5 – April 5, 2018 
 
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Ventilation 
 
The mode of ventilation for these cases will be standardized consistent with routine practice.  All 
of the patients will receive volume-controlled ventilation at a tidal volume of 6-8 ml/kg (5 cm 
PEEP).  The respiratory rate will be adjusted at the discretion of the anesthesiologist to maintain 
an end-tidal CO2 of 30-40 mmHg during the surgical procedure.  
 
Study measurements during anesthesia 
 
Primary Outcomes 
Peak Airway Pressures: Airway pressures will be measured every 1 minute. 
 
Secondary Outcomes 
Mean Airway Pressure: In addition to the Peak airway pressure, the mean airway pressure will 
also be recorded every 5 minutes during the procedure.  
 
Hemodynamic monitoring 
 
Blood pressure and heart rate will be measured using the noninvasive blood pressure cuff and 
standard three lead EKG, respectively every 1 minute during the interval in which the peak airway 
pressures are being measured (“deep” vs. “moderate”).  
 
Additional variables 
 
Additional variables will include duration of surgery, drug dosages (propofol, opioids, muscle 
relaxant, reversal agent, glycopyrrolate, other agents used during anesthesia), and duration from 
reversal to extubation.  Standard extubation criteria will be (SpO2 >98% on 100% FiO2, RR <35, 
TV > 5 ml/kg).  
 
Surgical rating 
 
During the procedure, the surgical condition will be scored by the surgeon using a five-point SRS. 
To reduce variability in the surgical rating, all surgeries will be performed by a core group of 
surgeons who will receive training in how to report this information.  
The rating scale will be a five-point ordinal scale ranging from 1 = poor condition to 5 = optimal 
surgical conditions (see appendix, Table 1). The surgeon scores the condition at 15-minute 
intervals. In case of a sudden change in surgical conditions, additional scores are obtained. If 
conditions are poor (score 1 or 2), muscle relaxation can be increased (in effect converting patient 
from moderate to deep according to methodology specified in this protocol using the rocuronium 
infusion). 

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Study measurements in the post-anesthesia care unit 
 
In the recovery room, the following variables will be measured by a different study personnel, 
when possible, at 15 min intervals for the first 1 hour: respiratory rate, arterial oxygen saturation, 
numerical pain rating (on a scale from 0, no pain, to 10, most severe pain imaginable), occurrence 
of nausea or vomiting, and level of sedation or alertness. The level of sedation/alertness will be 
assessed in the recovery room using the validated Leiden Observer’s Assessment of 
Alertness/Sedation (see appendix, table 2).  Additionally, the patient’s maximum inspired volume 
will be assessed 30 minutes after arrival in the PACU via the use of an incentive spirometer.  
Post-operative day 1 follow up 
 
QoR 9 on post op day 1 (via phone or in person)17 
Other parameters 
 
Time to optimal extubation conditions from the moment of reversal (with optimal conditions 
defined as TOF 4 with ratio >90%), time in the post-anesthesia care unit, and drug consumption 
will be recorded. 
 
Safety evaluations 
 
Serious adverse events (SAE) that occur during the study will be recorded in the case report form. 
The AE record in the case report form includes the nature of the event (with onset date and time, 
end date and time), severity, treatment, outcome, and the relationship to the treatment given. All 
AEs that meet reporting criteria will be reported to the medical ethics committee and authorities, 
as required by the GCP/GRP guidelines. 
 
Statistical Analysis 
Airway Pressure, Intra-abdominal pressure, Respiratory rate, arterial oxygen saturation, blood 
pressure, heart rate 
In order to obtain the most accurate measurements possible, multiple readings for the primary 
outcome (peak airway pressure) and secondary outcomes (respiratory rate, arterial oxygen 
saturation, blood pressure, and heartrate) will be collected once per minute for a maximum of 20 
minutes per treatment period. Summary measures (i.e. descriptive statistics including mean ± 
standard deviation, median, and interquartile range) for each data element will be generated for 
each patient, per each treatment period. Depending on the distribution of the peak airway pressure 
variable (as tested by Shapiro-Wilk tests), either a paired t-test or Wilcoxon Sign Rank test will be 
used to compare peak airway pressure between the two treatment conditions. Secondary outcomes 

Protocol version 5 – April 5, 2018 
 
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(respiratory rate, arterial oxygen saturation, blood pressure, and heartrate) will also be examined 
in a similar way for differences between the two treatment groups. P-values will be reported at the 
95% confidence level.   
Additionally, linear mixed effects models will be used for the peak airway pressure outcome, with 
treatment group and time as fixed effects, and subject as random effect.  Group effect size and p-
value will be reported at the 95% confidence level.   
Duration from reversal to extubation 
Summary statistics (mean ± standard deviation, median, IQR) will be summarized for each 
treatment condition. Two-sided t-test for independent groups will be used to compare the above 
variables between the two groups. P-values will be reported and 95% confidence interval of group 
difference will also be reported. Wilcoxon rank sum test will be used instead in the rare event of 
non-normality. 
Surgical rating scores 
Summary statistics (mean ± standard deviation, median, IQR) will be computed for surgical rating 
scores for each patient, per each treatment group. Wilcoxon sign rank tests will be used to compare 
surgical rating score between the two groups. P-values will be reported and 95% confidence 
interval of group difference will also be reported.  
Numerical pain rating, occurrence of nausea or vomiting, and level of sedation or alertness 
Numerical pain rating score and level of alertness will be presented as a graphical display of 
treatment group mean or median over each of the four time points in the recovery room. 
Contingency table (condition*group*time) for nausea/vomiting will be presented.  GEE 
(Generalized estimating equation) will be used to compare the recovery room variables between 
the two treatment conditions with time and treatment group as covariates. Exchangeable 
correlation structure will be applied. The distribution of binary variable (occurrence of nausea or 
vomiting) is assumed to binomial, and the distribution of other ordinal variables are assumed to 
poison or negative-binomial based on the nature of data.   
Power analysis 
We will assume a normal distribution. Using the values found in the Casanova article,18 we expect 
the difference in moderate versus deep block peak airway pressures to be approximately 2 cmH2O, 
with a standard deviation of 5. Converting these numbers to mmHg, we expect to see a difference 
of 1.48 mmHg, and a standard deviation of 3.68 mmHg. Using an α=0.05, we will need around 52 
patients for a paired t-test to have approximately 81% power to detect a difference between 
moderate and deep peak airway pressures. We plan to enroll approximately 120 patients to account 
for drop outs.
 
 

Protocol version 5 – April 5, 2018 
 
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Appendix 
 
Table 1 Surgical rating score 
 
1 
Extremely poor conditions 
2 
Poor conditions 
3 
Acceptable conditions 
4 
Good conditions 
5 
Optimal conditions 
 
 
Table 2. Observer’s Assessment of Alertness and Sedation scale 
  
 
 
 
 
 
 
 
 
 
 
 

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Figure 1: Trial Timeline 
 
 
 

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