Intubation Conditions Achieved With Rapid Co-administration of Rocuronium and Propofol Versus Classical Induction: A Prospective Randomized and Blind Trial
Phase: PHASE4
Conditions: Anesthesia
Sponsor: The University of Texas Health Science Center, Houston

IRB NUMBER: HSC-MS-22-0495 
IRB APPROVAL DATE: 01/28/2025 
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Intubation Conditions Achieved With Rapid Co-administration of Rocuronium and 
Propofol Versus Classical Induction: A Prospective Randomized and Blind Trial 
 
NCT05509192 
 
Version Date: 01/28/2025 
 
 
 
 
 
 
 
 
 
 
 

IRB NUMBER: HSC-MS-22-0495 
IRB APPROVAL DATE: 01/28/2025 
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Title: Intubation conditions achieved with rapid co-administration of Rocuronium 
and Propofol versus classical induction: 
A Prospective Randomized and Blind Trial. 
 
 
PI: Lauren M. Nakazawa, MD, Department of Anesthesiology, McGovern Medical School 
 
Co-PI: Yandong Jiang, MD. Ph.D., Department of Anesthesiology, McGovern Medical School 
Co-PI: Travis Markham, MD, Department of Anesthesiology, McGovern Medical School 
Other Research Team Members: Kyle Alyson Chi, MD; Carolyn Fan, MD; Megan Rodriguez 
(4th-Year Medical Student), McGovern Medical School 

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IRB APPROVAL DATE: 01/28/2025 
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Content 
Page number 
1. Background 
3 
2. Hypothesis 
6 
3. Specific Aims 
7 
4. Patient Enrollment & Randomization 
7 
5. Outcome 
8 
6. Study Protocol 
9 
7. Data Acquisition and Analysis 
11 
8. Predicted Outcome and Its Significance 
11 
9. Sample Size Calculation 
12 
10. Risk Assessment 
11. Data Safety Monitoring 
13 
12. Reporting of Adverse Events/Unanticipated Problems involving 
14 
Risk to Participants 
13. Privacy/Confidentiality Issues 
15 
14. Follow-up and Record Retention 
15 
15. Milestones of the Study 
15 
16. Cost and Resources 
15 
17. References 
17 
18. Appendix 
18 

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1. Background 
In the past century, measures have been increasingly implemented in the field of 
anesthesia to combat the incidence of preoperative and perioperative complications. 
However, management of a difficult airway in perioperative settings, emergency rooms, 
critical care units, and pre-hospital settings remains challenging. Due to this, suboptimal 
outcomes associated with management of patients with a difficult airway can occur, 
particularly if the difficulty is unexpected. A difficult airway can be due to difficult mask 
ventilation, difficult ventilation with supraglottic airway, and difficult tracheal intubation. 
The most severe scenario of difficult airway is when a “cannot intubate and cannot ventilate” 
scenario is encountered, the patient’s oxygenation is significantly compromised, and the 
return of effective spontaneous breathing is not possible in a timely fashion. The 
recommended default rescue measure is invasive airway access(1, 2) However, a large-scale 
study demonstrated that the success rate of invasive airway access performed by experienced 
anesthesiologists is only about 35%.(3) Therefore, the search for an alternative way to save 
the lives of patients with difficult airways is an unmet demand and requires urgent attention 
and effort. 
Management of a difficult airway has focused on the improvement of ventilation and 
intubation. Resumption of spontaneous breathing is the last option before invasive airway 
access is attempted. Previous reports indicate that the return of effective spontaneous 
breathing is unlikely in most patients if a “cannot intubate and cannot ventilate” event is 
encountered, due to the limits of safe apnea time.(4) This is particularly true if 
succinylcholine is used, as there is no reversal agent for succinylcholine-induced muscle 
paralysis. The time of muscle tone recovery to 50% of the baseline value after a single bolus 
of succinylcholine with induction dose (1 mg/kg) can reach 8.5 minutes on average.(4) 

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Recently, sugammadex was made available to reverse the muscle paralysis achieved with 
vecuronium and rocuronium.(5, 6) Complete reversal can be obtained within 2 minutes if an 
adequate dose of sugammadex is administered after a routine induction dose of rocuronium 
(0.6 mg/kg). The availability of sugammadex has the potential to change current anesthetic 
guidelines. However, its advantages have not been systemically assessed. 
In a classic anesthetic induction, a sedative-hypnotic medication such as propofol is 
administered. After an IV bolus of propofol (1-2 mg/kg) is given, it reaches its peak level in 
the brain in about 1 minute and quickly declines.(7) For classic induction (CI), a bolus of 
neuromuscular blocking drug (NMBD), commonly rocuronium (0.6 mg/kg), is administered 
after the provider attempts mask ventilation and proves its effectiveness. However, new 
recommendations state that a paralytic agent should be administered if mask ventilation is 
proven difficult or impossible.1 Therefore, attempted mask ventilation wastes time if a 
“cannot ventilate and cannot intubate” scenario is encountered. In addition, classic teaching 
has two more major disadvantages. First, the majority of “cannot intubate and cannot 
ventilate” situations are not anticipated. Second, most aspiration events that occur during 
induction are with mask ventilation. Therefore, the classic airway management of an 
unanticipated difficult airway is not optimized, particularly in terms of utilizing apnea 
oxygenation time. 
A “time principle induction” (TPI) has been tested by an administration of a non- 
depolarizing neuromuscular-blocking agent before a sedative-hypnotic is given in the 
operating room setting.(8-13) It is also tested in an emergency room setting and has been 
proven that there are no differences in intubating conditions and the success rate of first 
attempted intubation between the two approaches, CI and TPI.(14) However, even with the 

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non-inferiority results of TPI vs. CI, the sample size of the previous studies were small. More 
importantly, the non-depolarizing paralytic agent was given 20 seconds before administering 
a sedative,(8) or the sedative was given at the onset of clinically observed muscle 
weakness.(9) (10) (11) (12) (13) Therefore, patient awareness of muscle paralysis before a 
loss of consciousness and post-operative recall is of great concern, although previous studies 
have not demonstrated whether this occurs. 
The TPI can be modified – Modified Time Principle Induction (MTPI) – by 
administering a sedative and a neuromuscular blocking agent nearly simultaneously to 
minimize the likelihood of awareness of muscle paralysis before a loss of consciousness 
(Figure 1). In CI, a propofol bolus (1-2 mg/kg) will typically result in apnea in about 60 
seconds. Attempted mask ventilation, followed by administration of NMBD, will take over 3 
minutes, as it takes about 3 minutes to reach maximal muscle paralysis. If an intubation 
attempt is unsuccessful followed by an unsuccessful supraglottic airway (SGA) insertion, this 
will likely encompass an additional two minutes of time. If sugammadex (16 mg/kg) is given 
with return of adequate spontaneous breathing occurring 2 minutes after administration, the 
total apnea time will be 8 minutes. In a MTPI, patients would receive a non-depolarizing 
NMBD first, like rocuronium (0.6 mg/kg), immediately followed by a sedative-hypnotic, like 
propofol 1-2 mg/kg, without waiting for the onset of muscle weakness. Once apnea occurs, 
attempted intubation starts. If the intubation is not successful, it is followed by attempted 
mask ventilation, and then SGA ventilation (each step takes 1 minute). If none of them are 
successful, sugammadex is given. A total of 5 minutes of apnea time is needed to regain 
adequate spontaneous breathing. The apnea oxygenation time is shortened by 3 minutes or by 
43%. Therefore, the need for invasive airway management will likely be reduced. Since the 

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sedative-hypnotic and muscle relaxant are administered simultaneously, the awareness of 
paralysis before loss of consciousness is unlikely to occur. 
 
Figure 1. Schematic demonstration of intubating conditions created by Classic Induction vs. 
Modified Time Principle Induction (MTPI) with propofol and rocuronium. Propofol 
concentration in plasma in the brain (red line). Rocuronium induced muscle paralysis for 
classic induction (blue solid line) and Modified Time Principle Induction (green solid line). 
Muscle paralysis reversal after Sugammadex after MTPI (green dotted line) and classic 
induction (blue dotted line). 
 
 
2. Hypothesis 
 
Intubation conditions between patients receiving MTPI and CI are comparable. We will 
test this hypothesis by comparing time to intubation between the two techniques. 

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3. Specific aims 
 
3.1 To assess and compare the conditions for tracheal intubation obtained with MTPI and 
that obtained with CI. 
3.2. To compare the efficiency of tracheal intubation with the two induction techniques. 
 
3.3. To determine the rate of awareness during induction and post-operative recall of 
muscle weakness. 
 
 
4. Patient enrollment 
 
This study will be carried out in the main operating rooms at Memorial Hermann 
Hospital in the Texas Medical Center (TMC). The study team will approach the patients in 
the respective preoperative holding area after reviewing their medical records to determine 
eligibility. Once the study team believes that a particular patient is eligible to participate in 
the study, the study team will provide that patient with detailed information about the study 
and obtain informed consent from the patient. 
4.1. Inclusion criteria: 
 
I. 18 or older years of age 
 
II. BMI >30 kg/M2 or Mallampati class III or IV 
 
III. Requiring general anesthesia and endotracheal intubation 
 
4.2. Exclusion criteria: 
 
I. Acute and chronic respiratory disorders, including COPD and asthma 
 
II. ASA physical status classification > III 
 
III. Emergency surgery 
 
IV. Induction requiring cricoid pressure 

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V. Patients requiring awake intubation 
 
VI. Pregnant women 
 
VII. Patients who require an induction dose of propofol less than 1 mg/kg 
 
VIII. Untreated ischemic heart disease 
 
IX. Contraindication to mask ventilation 
 
X. Allergy to propofol, rocuronium, or Sugammadex 
 
XI. Induction requiring succinylcholine 
Randomization and Blinding 
Patients will be randomly assigned to the MTPI group and the Classic Induction group 
(control) using an online randomization program (https://www.randomizer.org/#randomize). A 
concealed envelope will be opened prior to induction. A study arm specific handout of induction 
instructions will be handed to the anesthesia provider. Laryngoscopy will be done with C-MAC 
and the entire laryngoscopy and entire intubation procedure will be recorded and saved. Study 
team members converting the video recorded data to digital data will be blind to the 
interventions. Once the study is completed and the digital data is collected, the study team 
members will be unblinded. 
 
 
5. Outcomes 
 
5.1 Primary outcome: The time between laryngoscope insertion into mouth and the onset 
of ventilation after tracheal intubation with MTPI vs. CI as visualized with C-MAC 
5.2 Secondary outcomes: 
 
5.2.1 The success rate of first attempted tracheal intubation, number of attempts, 
and failed intubation. 

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5.2.2 The best glottic view 
 
5.2.3 Provider determination of intubating conditions, based on whether 
intubation was classified as “Not difficult” or “Difficult” 
5.2.4 Vital signs during intubation including HR, BP, end-tidal CO2, and SpO2 
 
5.2.5 Injury associated with intubation, including injury of teeth, lips, tongue, 
and pharyngeal bleed 
5.2.6 Patients’ physical response during intubation, including moving and 
coughing 
5.2.7 Post-operative survey in PACU and post-operative day #1 to assess 
awareness of muscle paralysis before loss of consciousness, sore throat, 
nausea, and vomiting, and overall satisfaction. Please refer to the post- 
operative survey form. 
5.2.8 Recollection of pain on induction. 
 
 
6. Study protocol 
 
After providing informed consent, the subjects will receive premedication in the usual 
manner. Premedication typically includes 0-2 mg of IV midazolam at the discretion of the 
care team. Subjects will then be transported to the operating room and placed on the 
operating room table in the supine position with the head in the neutral position on a pillow. 
Operators who will perform endotracheal intubation are limited to an anesthesiology 
attending, anesthesiology residents who have performed greater than 75 endotracheal 
intubations, a CRNA or Anesthesia Assistant with working experience greater than 1 year. 

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Mask ventilation or supraglottic ventilation will be utilized if the first intubation attempt is 
not successful. 
Standard monitors for general anesthesia will be applied, including ECG, blood pressure, 
pulse oximetry, and capnography. Pre-oxygenation via a plastic mask will be carried out with 
a flow rate of 10-liter min−1 of 100% O2 until the expired O2 concentration reaches ≥80%. 
Randomization with random allocation of patients to a group and concealment of treatment 
from the patient and intubation scorer is carried out once informed consent is signed. Patients 
from both study groups will receive 1 mg/kg of lidocaine intravenously, followed by an 
opioid such as fentanyl (1-2 mcg/kg), prior to administration of induction drugs. Patients 
assigned to MTPI will then be given rocuronium (0.6mg/kg), followed by propofol 
intravenously as a single bolus within 10 seconds. A typical propofol bolus for induction 
ranges from 1-2mg/kg, depending on the patient’s age, medical history, and co-morbidities. 
Propofol dosing will be at the discretion of the care team. Patients will count down from one 
hundred. Once apnea occurs, as indicated by a lack of respiratory effort, the eyes will be 
taped, and intubation with C-MAC (Karl Storz 8403ZX, Tuttlingen, Germany) is initiated. 
An additional attempt of intubation is defined as the re-insertion of the C-MAC or insertion 
of another type of laryngoscope. The documentation of the intubation is performed by the 
study team. The laryngoscopy is continuously recorded and saved. The study team member 
who views the video of intubation and scores the difficulty of intubation and the glottic view 
is blind to the interventions. Patients assigned to CI will be induced as per routine care using 
lidocaine 1 mg/kg, an opioid such a fentanyl (1-2 mcg/kg), propofol 1-2 mg/kg, and 
rocuronium 0.6 mg/kg, and the intubation will be performed with a C-MAC. Patients will 
also count down from one hundred. The medications used for induction of anesthesia in both 

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arms of the study are those used for routine anesthesia care. In both study arms, dosing of 
medications for induction of anesthesia is standardized (lidocaine 1 mg/kg, fentanyl 1-2 
mcg/kg, propofol 1-2 mg/kg, and rocuronium 0.6 mg/kg). The only difference between the 
two arms will be the timing of the medication administration, and the order in which 
medications are administered. The documentation of induction and intubation will be the 
same as that of the MTPI group. Vital signs and other parameters will continuously be 
recorded in the intraoperative record. Emergence and extubation are not protocolized. Once 
the patient arrives in the PACU, the study team will assess the patient 30 min after arrival 
and attempt to conduct a post-operative survey (see PACU Patient Survey). 
 
 
7. Data acquisition and analysis 
 
All ventilatory settings and measured parameters displayed on the operating room 
ventilator (Datex Ohmeda AS/5, Helsinki, Finland), including expired tidal volume, flow 
waveforms, end-tidal carbon dioxide partial pressure, exhaled carbon dioxide waveforms, 
and vital signs displayed on the monitor will be recorded intra-operatively in the electronic 
medical record and video recorded from the time of pre-oxygenation and 5 minutes after 
intubation. Specific time points that will be collected are induction time, onset of apnea, 
beginning of intubation attempt, and time to successful intubation (identified by time 
between laryngoscope insertion into the mouth and the onset of ventilations after tracheal 
intubations with MTPI vs. CI with C-MAC). 
 
 
8. Predicted outcome and its significance 

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The study team assumes that MTPI will be non-inferior to CI in the rate of 1st attempt 
tracheal intubation success. Additionally, we predict no significant difference in intubation 
time, glottic view, rate of successful intubation, rate/severity of injury associated with 
tracheal intubation, and the rates of awareness of muscle paralysis before loss of 
consciousness using the two different types of approaches. The study team predicts that 
MTPI will create similar intubating conditions compared to CI and will shorten the apnea 
time by 3 minutes (a reduction in apnea time by 37.5%) if a “cannot intubate and cannot 
ventilate” scenario is encountered and sugammadex rescue is used to reverse muscle 
paralysis. By shortening apnea time, we expect that MTPI would improve difficult airway 
management and therefore patient outcomes. 
Positive outcomes expected from this study include increased efficiency in induction and 
intubation. Another benefit would be no longer needing to mask ventilate. Since 60% of 
aspiration occurs during mask ventilation, avoiding mask ventilation will significantly reduce 
aspiration rates. Also, a high dose (1.2 mg/kg) of rocuronium recommended for rapid 
sequence induction may not be needed. Furthermore, it is known that succinylcholine is 
associated with increased muscle aches, cardiac arrest, and mortality rates. The new method 
of modified time principle induction being done in this study may lead to a decreased need 
for succinylcholine as an option for muscle paralysis. 
 
 
9. Sample Size Calculation 
 
The primary outcome is time between laryngoscope insertion into mouth and the onset of 
ventilation after tracheal intubation in CI vs. MTPI as visualized with C-MAC. Among 
successful intubations, laryngoscopy time with a C-MAC averaged 46 seconds (95% CI, 40- 

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51).15 We assume the time required for tracheal intubation with the two induction approaches 
using a C-MAC is not significant if the time between the two approaches is smaller than 15 
seconds. With 80% power at 0.05 significance, a total sample size is 130 patients, with 65 
patients in each arm. To account for a drop rate of 15%, we will enroll a total of 154 patients. 
10. Risk Assessment 
 
10.1. Potential complications associated with induction and intubation are expected to 
be the same between the two groups. In another words, this study would be unlikely 
to add risk or reduce the existing potential risk of induction and intubation. 
10.2. Adverse effects of medications: Propofol and fentanyl are routinely used for 
anesthesia care. We will exclude the patients who are allergic to these two 
medications. Midazolam is routinely used as pre-medication. Any risk associated 
with these three medications will not be altered due to the study. All other 
medications will not be restricted to use for patient care including antiemetics. 
10.3. Patient awareness of muscle weakness before a loss of consciousness is a 
potential risk of the study. However, previous studies using a time principle 
induction have not demonstrated this in both the operating room and emergency 
room settings. Therefore, we do not anticipate any increased risks of awareness of 
muscle weakness in the study group when compared to the control group. 
 
 
11. Data Safety Monitoring 
 
11.1. A data safety monitor will review the trial protocol and the accumulated data on 
an ongoing basis for the duration of the trial. This individual will be monitoring the 

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benefits and risks to the participants of the trial in order to protect patient safety, 
credibility of the trial and validity of the study results. 
11.2. The data safety monitor will be unaffiliated with the study and will have no 
financial, scientific, or other conflict of interest with the trial. The data safety 
monitor will have experience in the proper conduct of clinical trials and statistical 
knowledge in order to evaluate the results of the data. 
11.3. The data safety monitor will perform data reviews at 30, 60, 90, 120, and 143 
patients, or sooner if indicated. 
11.4. Specific roles of the data safety monitor include oversight and analysis of study 
data to ensure continuing safety of trial participants, efficacy of the study 
intervention, and data integrity. By reviewing the data as it accumulates, the data 
monitor can identify significant trends or issues, and provide recommendations for 
changes in the study as needed. 
 
 
12. Reporting of Adverse Events or Unanticipated Problems involving Risk to 
Participants or others 
The study team does not anticipate increased risk of intraoperative events or other 
complications associated with this study as compared with routine care. Any adverse events 
and complications occurring in either group will be reported in the Data Collection Sheet. 
12.1. Adverse events (AE) will be obtained and documented by the investigators 
performing data collection and by questioning or examining the patient. All new 
complaints and symptoms (i.e., those not existing before the signing of informed 
consent) will be recorded on the AE CRF. 

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12.2. AE’s will be characterized in terms of their start and stop dates, start and stop 
times, intensity, action taken, relationship to research study, subject outcome, and 
whether the AE led to an SAE. 
12.3. The study team will perform a review of adverse events after enrollment of 20 
subjects. 
 
 
13. Privacy/Confidentiality Issues 
 
Measures will be taken to prevent lapses in confidentiality from occurring. Only key 
study personnel will have access to identified information. Exported and extrapolated data 
will be stored on a password protected UTHealth computer that only key study personnel can 
access. Any paper records will be kept in a drawer with a lock within Dr. Jiang’s office. 
 
 
14. Follow-up and Record Retention 
 
Records will be kept through the HIPAA-compliant servers of McGovern Medical 
School. All the documents will be kept in Dr. Markham’s office in the drawer with a lock. 
All research tests will be performed under a code that protects the identity of the participants. 
Records of experimental procedures will be kept at least 6 years following the publication of 
the study results. At that time, research data will be destroyed. 
 
 
15. Milestone of the study 
 
● August 15, 2022. Approval of IRB application 
 
● August 16, 2022. Initiation of the study 
 
● August 29, 2022. Completion of the study – the first 10 patients 

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● November 21, 2022. Completion of the study – first 100 patients 
 
● January 16, 2025. Completion of the study total 154 patients 
 
 
16. Cost and resources 
 
All the equipment needed for the study is for routine anesthesia care and is available in 
the operating room. Participation in this study will not cost more than that of ordinary care. 
Since this study imposes minimal risk, and little effort on the participants is needed, the 
participants will not be compensated and will be discussed at the time when consent is 
obtained. Dr. Markham will provide an encrypted laptop computer for the study team. 

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17. References 
 
1. 
Apfelbaum JL, Hagberg CA, Connis RT, Abdelmalak BB, Agarkar M, Dutton RP, et al. 2022 
American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway. 
Anesthesiology. 2022;136(1):31-81. 
2. 
Hagberg CA, Gabel JC, Connis RT. Difficult Airway Society 2015 guidelines for the management of 
unanticipated difficult intubation in adults: not just another algorithm. Br J Anaesth. 2015;115(6):812-4. 
3. 
Cook TM, Woodall N, Frerk C. Major complications of airway management in the UK: results of 
the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. 
Part 1: anaesthesia. Br J Anaesth. 2011;106(5):617-31. 
4. 
Benumof JL, Dagg R, Benumof R. Critical hemoglobin desaturation will occur before return to an 
unparalyzed state following 1 mg/kg intravenous succinylcholine. Anesthesiology. 1997;87(4):979-82. 
5. 
Sacan O, White PF, Tufanogullari B, Klein K. Sugammadex reversal of rocuronium-induced 
neuromuscular blockade: a comparison with neostigmine-glycopyrrolate and edrophonium-atropine. 
Anesth Analg. 2007;104(3):569-74. 
6. 
Jones RK, Caldwell JE, Brull SJ, Soto RG. Reversal of profound rocuronium-induced blockade with 
sugammadex: a randomized comparison with neostigmine. Anesthesiology. 2008;109(5):816-24. 
7. 
Kim KM, Choi BM, Park SW, Lee SH, Christensen LV, Zhou J, et al. Pharmacokinetics and 
pharmacodynamics of propofol microemulsion and lipid emulsion after an intravenous bolus and 
variable rate infusion. Anesthesiology. 2007;106(5):924-34. 
8. 
Nelson JM, Morell RC, Butterworth JFt. Rocuronium versus succinylcholine for rapid-sequence 
induction using a variation of the timing principle. J Clin Anesth. 1997;9(4):317-20. 
9. 
Sieber TJ, Zbinden AM, Curatolo M, Shorten GD. Tracheal intubation with rocuronium using the 
"timing principle". Anesth Analg. 1998;86(5):1137-40. 
10. 
Koh KF, Chen FG. Rapid tracheal intubation with atracurium: the timing principle. Can J Anaesth. 
1994;41(8):688-93. 
11. 
Chatrath V, Singh I, Chatrath R, Arora N. Comparison of intubating conditions of rocuronium 
bromide and vecuronium bromide with succinylcholine using "timing principle". J Anaesthesiol Clin 
Pharmacol. 2010;26(4):493-7. 
12. 
Culling RD, Middaugh RE, Menk EJ. Rapid tracheal intubation with vecuronium: the timing 
principle. J Clin Anesth. 1989;1(6):422-5. 
13. 
Silverman SM, Culling RD, Middaugh RE. Rapid-sequence orotracheal intubation: a comparison 
of three techniques. Anesthesiology. 1990;73(2):244-8. 
14. 
Driver BE, Klein LR, Prekker ME, Cole JB, Satpathy R, Kartha G, et al. Drug Order in Rapid 
Sequence Intubation. Acad Emerg Med. 2019;26(9):1014-21. 

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18. Appendix 
 
1: Grading System for Studied Intubation Methods 
Score 
Modified Time Principle 
Induction (MPTI) 
(n=) 
Classic Induction (CI) 
(n=) 
3 
2 
1 
0 
Induction condition scores: 3 (Excellent) – Jaw is fully relaxed, muscles completely paralyzed, 
and vocal cords are abducted. 2 (Good) – Similar to score 3 but with mild movement and 
coughing. 1 (Poor) – Strained or firm jaw; bucking action; and moving vocal cords. 0 (Failure to 
intubate). 

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2: Patient Post-Operative Survey 

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Patient Post-Operative Survey: Patients will fill out the survey in the PACU based on their 
experience. They will also document the last number they remember counting while in the 
operating room. The provider will later compare the number stated in the operating room 
(recorded separately) to the number the patient remembered in the PACU.