Conditions: Surgical Recovery Pain, Postoperative
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 30
Healthy volunteers: no

Brief summary:
Chronic pain, functional impairment and slow rates of recovery are key issues for patients after surgery and trauma. No preventative strategy in current use unequivocally modifies these rates, and few novel approaches have been tested. Furthermore, persistent postsurgical pain is a major route to chronic opioid use, opioid use disorder and, regrettably, opioid overdose. Most strategies designed to limit chronic pain or enhance functional recovery after surgery are directed at modulating peripheral and central nervous system activity and do not strongly modify the underlying tissue pathophysiology or fundamental systemic responses. Strategies limiting oxidative stress in the perioperative period, on the other hand, might limit tissue damage, organ dysfunction and immune system activation.

N-acetyl cysteine (NAC) is an antioxidant well-studied in the perioperative period; it is very safe, relatively inexpensive and widely available. The central hypothesis is, therefore, that perioperative administration of NAC will reduce perioperative oxidative stress, limit immune system activation and improve key indices of surgical recovery. Although the planned work will not comprehensively address this hypothesis, it will identify the most useful tools and help the researchers estimate the required sample sizes for more definitive externally funded efforts.

Detailed description:
This is a randomized, double-blind, placebo controlled interventional pilot study in 20 patients undergoing first-time total hip arthroplasty (THA) for chronic osteoarthritis at Stanford Medicine. The researchers will screen, enroll and collect biologic and behavioral data from 20 participants as outlined in previous observational and interventional clinical studies undertaken in close collaboration with the Department of Orthopedic Surgery. In particular, standard operating procedures for screening, recruiting, laboratory assessments, and clinical data collection are in place including eligibility screening via EPIC (EHR) ahead of patients' preoperative visit, coordinated recruitment and consenting during the pre-surgery visit including study- related laboratory work, further preoperative assessments after the visit (e.g. remote completion of questionnaires and direct import of results into REDCap), and real-time tracking of the data collection and storage process (e.g. including phone/email reminders if data are missing).

Repeated assessments of pain, physical function, and analgesic medication will be made before surgery, daily on postoperative days 1-3, and then twice a week in post-op weeks 1 - 6. Delirium will be measured days 1-3 while in-hospital. Additional data will include demographics (age, BMI, sex, race, and ethnicity), surgical/anesthesia data (e.g. duration), and medical/medication history.

Peripheral blood samples will be collected before surgery and 1hr and 24hr after surgery based on our prior study showing that monocyte activation (including STAT3, CREB and NFkB signaling responses in CD14+CD16- monocytes) early after surgery strongly correlates with delayed pain resolution and functional impairment. Exhaled breath samples will be collected intraoperatively prior to incision and at wound closure as well as at 1 and 24 hours after surgery.

N-Acetylcysteine infusion: A loading dose of 50 mg/kg will be started as a 1-hour infusion before surgical incision, and will be followed by a maintenance dose of 50 mg/kg administered over 4 hours. This is a standard dosing paradigm that is safe when used intraoperatively and rarely causes significant adverse effects (mainly allergic reactions).

Surgery and anesthesia: Participants will undergo unilateral hip arthroplasty performed by three surgeons using the same approach. The anesthetic and perioperative management of patients is standardized and follows ERAS-based recommendations.

Measures: Well-validated instruments will be used to assess pain, pain interference and function of the affected and operated joint including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) adapted for patients undergoing lower extremity joint surgery, the Brief Pain Inventory (BPI) and the Surgical Recovery Scale (SRS). Opioid consumption will be quantified as intravenous hydromorphone equivalents (milligram/day) using widely accepted opioid conversion tables.

Sample analysis: Blood and plasma will be collected and processed for analysis with mass cytometry as previously described. A 39-parameter human CyTOF antibody panel will be applied that will allow the simultaneous analysis of 1) all major immune cell phenotypes 2) endogenous intracellular signaling responses (including the pSTAT3, pCREB and pNF-kB signal) and 3) intracellular markers of reactive aldehydes (i.e. 4-HNE and MDA signal).

Breath samples will be analyzed for aldehydes including formaldehyde, crotenaldehyde, and benzaldehyde using mass spectroscopy in the laboratory of Dr. Gross.

Plasma samples will be analyzed for free MDA and 4- HNE in baseline, 1 and 24-hour plasma samples in the laboratory of Dr. Clark.

Analysis and modeling of outcome data: Self-reported outcomes will be analyzed using the validated models associated with each outcome to extract a quantified and normalized number associated with recovery. The 60Htz actigraphy data will first be mined for patterns associated with daily activities (e.g. step counts) and intensity levels. Next, a baseline will be established using the data collected during and prior to surgery, for each variable. All variables will be normalized to this baseline to account for patient-specific effects. Finally, a multivariate linear model (with days passed since surgery as the response variable) will be used to model the entire actigraphy dataset. The area under the respective recovery curve of each patient according to this model will be used as an objective recovery outcome. In our preliminary studies (data not shown) this outcome has been found to be correlated with several aspects of the immune system.

Analysis and modeling of CyTOF data: The large number of data points (millions of cells per patient) and measured variables (tens of signaling pathways in hundreds of cell types) pose unique computational challenges that cannot be addressed using traditional bioinformatics tools. The researchers will develop a Bayesian framework that will combine a priori knowledge of the immune system with state-of-the-art mass cytometry profiling to build a predictive model of innate and adaptive immune cell signaling responses for each of the recovery outcomes.

Arms:
arm 1: N-acetyl cysteine will be administered as follows: A loading dose of 50 mg/kg will be started as a 1-hour infusion before surgical incision, and will be followed by a maintenance dose of 50 mg/kg administered over 4 hours. arm 2: Normal will be administered as follows: A normal saline infusion will administered at a rate and duration to mimic the N-acetyl cysteine administration.

Interventions: intervention 1: N-acetyl cysteine intervention 2: Normal Saline
Intervention descriptions: intervention 1: Intravenous infusion started during the clinically indicated surgery at a rate of 50mg/kg over 1 hour followed by 50mg/kg over 3 hours. This will be an accumulated total of 100 mg/kg over 4 hours. intervention 2: Intravenous infusion at a time and rate to mimic the active treatment. The infusion will be given over 4 hours beginning during the clinically indicated surgery

Protocol document:
Prot_000.pdf: 
 
Oxidative Stress and Surgical Recovery 
NCT04732000 
December 13, 2023 
1. 
PURPOSE OF THE STUDY 
a. 
Brief Summary 
Chronic pain, functional impairment and slow rates of recovery are key issues for patients 
after surgery and trauma. Most approaches designed to limit chronic pain or enhance 
functional recovery focus on modulating peripheral or CNS responses and not on 
preventative strategieSs. Recent research suggests limiting oxidative stress in the 
perioperative period might limit tissue damage, organ dysfunction and immune system 
activation. These factors in turn may preemptively decrease pain and increase function 
post op. This study is designed to help determine the effectiveness of this strategy for 
improving postop recovery. 
b. 
Objectives 
Our central hypothesis is that perioperative administration of N-acetyl cysteine will 
reduce perioperative oxidative stress, limit immune system activation and improve key 
indices of surgical recovery. Although the planned work will not comprehensively 
address this hypothesis, it will solidify the required collaborations, identify the most 
useful tools and help the team estimate the required sample sizes for more definitive 
externally funded efforts. 
 
Note: N-acetyl cysteine (NAC) is an antioxidant well-studied in the perioperative period; 
it is safe, relatively inexpensive and widely available. 
c. 
Rationale for Research in Humans 
This is a study on oxidative stress and it's influence on surgical recovery in humans, 
necessitating human participants be involved. 
2. 
STUDY PROCEDURES 
a. 
Procedures 
Participants will be consented prior to the initiation of any study procedures. 
 
Participants will be recruited from the Stanford orthopedic population scheduled to 
undergo total hip replacement surgery. The anesthetic and perioperative management of 
patients will be standardized according to ERAS-based recommendations as outlined by 
the Stanford Anesthesia Department.  


December 13, 2023 
 
Page 2 of 11 
 
Participants will be randomized to be in 1 of 2 treatment groups.  
 
Group 1: An N-Acetylcysteine infusion will be administered to 50% of the participants 
during surgery as follows: IV infusion of 50 mg/kg over 1 hour followed by an additional 
50 mg/kg over 3 hours, making the total dose 100 mg/kg.  
 
Group 2: A placebo (Normal Saline) infusion will be given to in blinded fashion to the 
other 50% of patients  
 
1) Assessments of pain, physical function and analgesic medication use will be made 
before surgery, daily on postoperative days 1-3, and then twice a week through post-op 
week 6. Validated surveys and a patient diary will be used to collect this data. The 
surveys include the Western Ontario and McMaster Universities Osteoarthritis Index 
(WOMAC) adapted for patients undergoing lower extremity joint surgery, the Brief Pain 
Inventory (BPI), and the Surgical Recovery Scale (SRS).  
 
2) Delirium will be measured using the Confusion Assessment Method (CAM) days 1-3 
while in-house.  
 
3) Additional data will be collected including demographics, surgical/anesthesia data 
(e.g. duration), and medical/medication history. 4) Peripheral blood samples will be 
collected before surgery and 1hr and 24hr after surgery based on our prior study showing 
that monocyte activation early after surgery strongly correlates with delayed pain 
resolution and functional impairment. addition 2/8/2021: We will collect blood for 
genomic analysis once, at the time of the preop sample collection.  
 
5) Exhaled breath samples will be collected intraoperatively prior to incision and at 
wound closure as well as at 1 and 24 hours after surgery to be analyzed for aldehydes 
including formaldehyde, crotenaldehyde, and benzaldehyde.  
 
We will also collect clinical information including demographics, medical and 
medication history, medical/clinical course from surgery through 6 weeks post op. 
b. 
Procedure Risks  
N-acetyl cysteine is a powerful anti-oxidant used safely for a variety of conditions 
including acetaminophen overdose. While not without potential ill effects the dose 
chosen is low and considered safe given in the context of surgery. 
 
All other measures are safe and with only the risk of loss of confidentiality, or in the case 
of blood draws a very small risk of infection. 
c. 
Use of Deception in the Study 
Deception will not be used. 


December 13, 2023 
 
Page 3 of 11 
d. 
Use of Audio and Video Recordings 
No audio or video recordings will be made. 
e. 
Alternative Procedures or Courses of Treatment 
There is no alternative procedure beyond not participating. Standard care will not be 
altered if participants enroll in this project. 
f. 
Will it be possible to continue the more (most) appropriate therapy for the 
participant(s) after the conclusion of the study? 
NA 
g. 
Study Endpoint(s) 
We are not comparing treatments. The study will end when all participants have 
completed all study related procedures. 
3. 
BACKGROUND  
a. 
Past Experimental and/or Clinical Findings 
Chronic pain, functional impairment and slow rates of recovery are key issues for patients 
after surgery and trauma. Chronic pain after surgery, for example, affects 10-80% of all 
those having operations, while commonly performed hip and knee joint replacement 
surgeries have an approximately 25% rate of chronic pain and functional limitation [1]. 
No preventative strategy in current use unequivocally modifies these rates, and few novel 
approaches have been tested. Furthermore, persistent postsurgical pain is a major route to 
chronic opioid use, opioid use disorder and, regrettably, opioid overdose. Most strategies 
designed to limit chronic pain or enhance functional recovery after surgery are directed at 
modulating peripheral and central nervous system activity and do not strongly modify the 
underlying tissue pathophysiology or fundamental systemic responses. Strategies limiting 
oxidative stress in the perioperative period, on the other hand, might limit tissue damage, 
organ dysfunction and immune system activation. Within our department, the Gross lab 
has established expertise in pain and organ damage related to reactive aldehyde 
production, a measure of oxidative stress, and recently expanded their repertoire of assays 
to quantify reactive aldehydes in breath samples in volunteers although surgical patients 
have not been studied [2]. Likewise, the Clark lab has demonstrated the ability of 
antioxidants to reduce post-injury pain behaviors as well as reduce innate and adaptive 
immune system activation in laboratory animals [3]. This work has not been translated to 
human populations. On the other hand, Dr. Gaudilliere has developed leading edge 
techniques for the analysis of immune activation in human patients proven useful for 
understanding the cellular correlates of postoperative pain and recovery [4]. One cell type 
strongly linked to pain and delayed recovery from orthopedic surgery, monocytes, are 
strongly activated by oxidative stress [5], suggesting that oxidative stress may be a 
critical early mechanism having persistent impact on surgical recovery.  
 
The design of clinical trials useful for understanding the efficacy of perioperative 
treatments for enhancement of recovery is a focus of Dr. Angst's, while the analysis of 


December 13, 2023 
 
Page 4 of 11 
complex datasets and incorporation of innovative statistical approaches in the forte of Dr. 
Aghaeepour [4, 6, 7]. The skills of these two investigators will assure that the study is 
well designed and that the analysis will yield the maximum quantity of data.  
 
N-acetyl cysteine (NAC) is an antioxidant well-studied in the perioperative period; it is 
very safe, relatively inexpensive and widely available. Our central hypothesis is, 
therefore, that perioperative administration of NAC will reduce perioperative oxidative 
stress, limit immune system activation and improve key indices of surgical recovery. 
Although the planned work will not comprehensively address this hypothesis, it will 
solidify the required collaborations, identify the most useful tools and help the team 
estimate the required sample sizes for more definitive externally funded efforts.  
 
References  
1. Kim, D.H., et al., Predictive Factors for Developing Chronic Pain After Total Knee 
Arthroplasty. J Arthroplasty, 2018. 33(11): p. 3372-3378.  
2. Zambelli, V.O., et al., Aldehyde dehydrogenase-2 regulates nociception in rodent 
models of acute inflammatory pain. Sci Transl Med, 2014. 6(251): p. 251ra118.  
3. Guo, T.Z., et al., Oxidative Stress Contributes to Fracture/Cast- Induced Inflammation 
and Pain in a Rat Model of Complex Regional Pain Syndrome. J Pain, 2018. 19(10): p. 
1147-1156.  
4. Gaudilliere, B., et al., Clinical recovery from surgery correlates with single-cell 
immune signatures. Sci Transl Med, 2014. 6(255): p. 255ra131.  
5. Geiger-Maor, A., et al., Cells exposed to sublethal oxidative stress selectively attract 
monocytes/macrophages via scavenger receptors and MyD88-mediated signaling. J 
Immunol, 2012. 188(3): p. 1234-44.  
6. Aghaeepour, N., et al., Deep Immune Profiling of an ArginineEnriched Nutritional 
Intervention in Patients Undergoing Surgery. J Immunol, 2017.  
7. Fragiadakis, G.K., et al., Patient-specific Immune States before Surgery Are Strong 
Correlates of Surgical Recovery. Anesthesiology, 2015. 123(6): p. 1241-55.  
8. Pereira, J.E.G., et al., N-acetylcysteine use among patients undergoing cardiac surgery: 
A systematic review and meta-analysis of randomized trials. PLoS One, 2019. 14(5): p. 
e0213862.  
9. Kapstad, H., B. Rokne, and K. Stavem, Psychometric properties of the Brief Pain 
Inventory among patients with osteoarthritis undergoing total hip replacement surgery. 
Health Qual Life Outcomes, 2010. 8: p. 148.  
10. Baca, Q., et al., Predicting Acute Pain After Surgery: A Multivariate Analysis. Ann 
Surg, 2019.  
11. Aghaeepour, N., et al., Critical assessment of automated flow cytometry data analysis 
techniques. Nat Methods, 2013. 10(3): p. 228-38. 
b. 
Findings from Past Animal Experiments 
Excerpt from above: ...the Clark lab has demonstrated the ability of antioxidants to 
reduce post-injury pain behaviors as well as reduce innate and adaptive immune system 
activation in laboratory animals [3]. This work has not been translated to human 
populations. 
 


December 13, 2023 
 
Page 5 of 11 
4. 
RADIOISOTOPES OR RADIATION MACHINES 
a. 
Standard of Care (SOC) Procedures 
Identify Week/Month of Study 
Name of Exam 
Identify if SOC or Research 
NA 
NA 
NA 
b. 
Radioisotopes 
i. 
Radionuclide(s) and chemical form(s) 
NA 
ii. 
Total number of times the radioisotope and activity will be administered (mCi) and 
the route of administration for a typical study participant 
NA 
iii. 
If not FDA approved: dosimetry information and source documents (package insert, 
Medical Internal Radiation Dose [MIRD] calculation, and peer reviewed literature) 
NA 
c. 
Radiation Machines – Diagnostic Procedures 
i. 
Examination description (well-established procedures) 
NA 
ii. 
Total number of times each procedure will be performed (typical study participant) 
NA 
iii. 
Setup and techniques to support dose modeling 
NA 
iv. 
FDA status of the machine and information on dose modeling (if procedure is not 
well-established) 
NA 
d. 
Radiation Machines – Therapeutic Procedures 
i. 
Area treated, dose per fraction/number of fractions, performed as part of normal 
clinical management or due to research participation (well-established procedures) 
NA 
ii. 
FDA status of the machine, basis for dosimetry, area treated, dose per fraction and 
number of fractions (if procedure is not well-established) 
NA 
 
 
 


December 13, 2023 
 
Page 6 of 11 
5. 
DRUGS, BIOLOGICS, REAGENTS, OR CHEMICALS USED IN THE STUDY 
a. 
Investigational Drugs, Biologics, Reagents, or Chemicals 
N/A 
b. 
Commercial Drugs, Biologics, Reagents, or Chemicals 
Commercial Product 1 
Name: 
N-Acetyl Cysteine 
Dosage: 
100 mg/kg total dose 
Administration Route 
IV administration 
50mg/kg over 1 hour then 50 mg/kg over 3 hours. 
New and different use? (Y/N) 
Y 
Commercial Product 2 
Name: 
NA 
Dosage: 
NA 
Administration Route 
NA 
New and different use? (Y/N) 
NA 
Commercial Product 3 
Name: 
NA 
Dosage: 
NA 
Administration Route 
NA 
New and different use? (Y/N) 
NA 
6. 
PARTICIPANT POPULATION 
a. 
Planned Enrollment 
i) 
30 participants enrolled with an expected 20 to complete all study 
procedures.  
ii) 
30  
iii) 
Orthopedic surgery patients undergoing clinically indicated total hip 
arthroplasty. 
b. 
Age, Gender, and Ethnic Background 
18 years of age or older  
Both men and women  
All ethnic backgrounds 
c. 
Vulnerable Populations 
Vulnerable subjects will not be enrolled. 
d. 
Rationale for Exclusion of Certain Populations 
Pregnant women and children will not be enrolled. THA surgeries are not performed on 
pregnant women. Children will not be included as THA surgery would only be done in 
extremely rare cases. 


December 13, 2023 
 
Page 7 of 11 
e. 
Stanford Populations 
Participants who are laboratory personnel, employees, and/or students will not be 
targeted for enrollment but will not be excluded. All participants will undergo the same 
evaluation for inclusion. 
f. 
Healthy Volunteers 
There will be no healthy volunteers enrolled. 
g. 
Recruitment Details 
Participants will be consented in the clinic after a clinician in either the orthopedic or pre 
anesthesia clinic has gained permission from the patient to discuss this research project 
with the research team. We will gather PHI from the electronic medical record prior to 
consenting patients to ensure basic inclusion criteria are met prior to engaging individual 
patients. A request for a waiver of authorization for recruitment is included in this 
application.  
 
In some cases when we are not able to meet patients in the clinic as described above we 
will contact them by phone or secure zoom call to present the study. Participants can 
choose to either schedule an appointment for in person consent or consent using a secure 
REDCap consent form.  
 
A telephone screen is attached to section 16 for use when appropriate.  
 
In all cases patients will not be cold-called and will only be contacted by someone with a 
treating relationship, or called if someone with a treating relationship gets the patients 
approval for the call.  
 
9/14/21: We will use the new part 11 compliant Adobe Sign process for remote consent 
when appropriate.  
 
5/11/22: We will partner with the Research Participation team for Honest Broker 
outreach. Potential participants are identified via STARR and invited by Research 
Participation team (honest broker) on behalf of study team. See Section 16 for Honest 
Broker study invitation letters. We will be using MyHealth. Epic MyChart, study team 
receives only the interested responses via Epic MyChart In Basket. 
h. 
Eligibility Criteria 
i. 
Inclusion Criteria 
1) Over 18  
2) Male of female  
3) Planning to undergo primary total hip arthroplasty  
4) Fluent in English  
5) Willing and able to sign an informed consent form and HIPAA authorization and 
to comply with study procedures 


December 13, 2023 
 
Page 8 of 11 
ii. 
Exclusion Criteria 
1) Infectious disease within the last month  
2) Immune-suppressant therapy within the last 2 months (e.g., azathioprine or 
cyclosporine)  
3) Chronic medication with potential immune-modulatory effects (e.g., daily oral 
morphine-equivalent intake > 30 mg)  
4) Major surgery within the last 3 months or minor surgery within the last month.  
5) History of substance abuse (e.g., alcoholism, drug dependency)  
6) Pregnancy  
7) Autoimmune disease interfering with data interpretation (e.g. lupus)  
8) Renal, hepatic, cardiovascular, or respiratory diseases resulting in clinically 
relevant impaired function  
9) Active malignancy  
10) Participation in another clinical trial of an investigational drug or device within 
the last month that, in the investigator's opinion, would create an increased risk to the 
participant or compromise the integrity of the study  
11) Other conditions compromising a participant's safety or the integrity of the study 
12) History of anaphylaxis 
i. 
Screening Procedures 
Patients will be prescreened by reviewing the e-medical record for documented exclusion 
criteria. At the time of consent participants will be interviewed to confirm eligibility 
criteria is met. 
j. 
Participation in Multiple Protocols 
We will ask participants if they are engaged in other research projects at the time of 
enrollment.  
 
Participants will not be enrolled if they are currently engaged in another trial if their 
safety or the integrity or either study would be at risk. 
k. 
Payments to Participants 
Participants will be paid $150; $75 following hospitalization, and $75 at the completion 
of the 6-week post op follow up. 
l. 
Costs to Participants 
There will be no cost to the participant. 
m. 
Planned Duration of the Study 
1) Screening per participant will take approx. 15 minutes.  
2) Active participation will take approx. 7 weeks from consent through 6 week follow up. 
3) Data analysis will take approx. 6 months.  
 
Overall recruitment and completion of participant involvement in the trial will take 
approximately 1 year. 


December 13, 2023 
 
Page 9 of 11 
7. 
RISKS 
a. 
Potential Risks 
i. 
Investigational devices 
NA 
ii. 
Investigational drugs 
NA 
iii. 
Commercially available drugs, biologics, reagents or chemicals 
In the literature the most frequently reported adverse events attributed to I.V. 
acetylcysteine administration were rash, urticaria, and pruritus. The frequency of adverse 
events has been reported to be between 0.2% and 20.8%, and they most commonly occur 
during the initial loading dose of acetylcysteine.  
 
Adverse effects reported following acetylcysteine infusion given to treat acetaminophen 
overdose include:  
Tachycardia  
Ear pain  
Nausea and vomiting  
Chest tightness/feeling hot  
Anaphylactoid reaction ~ 10% mild to moderate / 1% severe reaction  
Rhonchi/throat tightness  
Rash/flushing/pruritis 
iv. 
Procedures 
Blood draws carry a small risk of bleeding, bruising, pain and infection.  
 
Breath analysis carries no calculable risk.  
 
Completion of surveys carries the risk of loss of confidentiality. 
v. 
Radioisotopes/radiation-producing machines 
NA 
vi. 
Physical well-being 
As mentioned above. 
vii. 
Psychological well-being 
None known 
viii. 
Economic well-being 
None 
ix. 
Social well-being 


December 13, 2023 
 
Page 10 of 11 
None known 
x. 
Overall evaluation of risk 
Low - innocuous procedures such as phlebotomy, urine or stool collection, no therapeutic 
agent, or safe therapeutic agent such as the use of an FDA approved drug or device. 
b. 
International Research Risk Procedures 
NA 
c. 
Procedures to Minimize Risk 
Blood draws: Blood will be drawn using sterile supplies and aseptic technique. All 
Stanford policies regarding blood draws will be followed.  
 
Loss of confidentiality: All PHI/confidential information will be kept from casual view, 
and managed and stored by trained research staff following all HIPAA and Stanford 
policies.  
 
N-acetylcysteine infusion: Infusions will take place in the operating room and PACU 
where trained medical staff will be in attendance and available to intervene in the 
unlikely event of an adverse event requiring medical intervention. 
d. 
Study Conclusion 
The experiment will terminate when all study participants have concluded all study 
procedures 
e. 
Data Safety Monitoring Plan (DSMC) 
i. 
Data and/or events subject to review 
This study does not fall into the category of those requiring DSMPs as describe in the 
guidance provided above. Data and study procedures will be continually evaluated as 
the study progresses. Research team meetings are held weekly and problems 
associated with study conduct are discussed as needed (daily if necessary) with the 
PI. 
ii. 
Person(s) responsible for Data and Safety Monitoring 
NA 
iii. 
Frequency of DSMB meetings 
NA 
iv. 
Specific triggers or stopping rules 
NA 
v. 
DSMB Reporting 
NA 


December 13, 2023 
 
Page 11 of 11 
vi. 
Will the Protocol Director be the only monitoring entity? (Y/N) 
Y 
vii. 
Will a board, committee, or safety monitor be responsible for study monitoring? 
(Y/N) 
N 
f. 
Risks to Special Populations 
NA 
8. 
BENEFITS 
There is some hope that participants recovery will be positively affected by the infusion of N-
acetylcysteine though this is not guaranteed. Acquisition of knowledge regarding oxidative stress, 
and use of antioxidants in the context of surgery and trauma may impact medical practice and 
significantly benefit patients in the future. 
9. 
PRIVACY AND CONFIDENTIALITY 
All participant information and specimens are handled in compliance with the Health Insurance 
Portability and Accountability Act (HIPAA) and privacy policies of Stanford University, Stanford 
Health Care, and Stanford Children’s Health.