How do You Take Your Coffee Before Anesthesia: A Randomized Controlled Crossover Study Comparing Gastric Emptying With Black Coffee vs Coffee With Cream
Phase: NA
Conditions: Anesthesia, Aspiration, Fasting
Sponsor: University of Arkansas

 
Version #: 5 
Date: 12/29/2020Page 1 
 
Title: How do you take your coffee before anesthesia? A randomized controlled 
crossover study comparing gastric emptying with black coffee vs coffee with 
cream. 
 
NCT: 04786691 
 
Date: 12/29/2020 
 

Title:  How do you take your coffee before anesthesia? A randomized controlled crossover study 
comparing gastric emptying with black coffee vs coffee with cream. 
PI: Jessica Yeh, MBBS 
 
Version #: 5 
Date: 12/29/2020Page 2 
 
 
 
 
Study Title: 
How do you take your coffee before anesthesia? A 
randomized controlled crossover study comparing gastric 
emptying with black coffee vs coffee with cream. 
 
Principal Investigator:  
Jessica Yeh, MBBS 
University of Arkansas for Medical Sciences 
4301 W. Markham Street, Slot # 515 
Little Rock, AR 72205 
Telephone:  (501) 686-6114 
Email:  jyeh@uams.edu 
 
 
Sub-Investigator (s): 
Nadir El Sharawi, MD 
 
University of Arkansas for Medical Sciences 
 
4301 W. Markham Street, Slot # 515 
Little Rock, AR 72205 
Telephone:  (501) 686-6114 
Email:  NElsharawi@uams.edu 
 
Mohamed Abdeldayem, MD, PhD 
University of Arkansas for Medical Sciences 
 
4301 W. Markham Street, Slot # 515 
Little Rock, AR 72205 
Telephone: (501) 686-6114 
Email: MAAbdeldayem@uams.edu 
 
 
Study location: 
University of Arkansas for Medical Sciences 
 
4301 W. Markham Street, Slot # 515 
Little Rock, AR 72205 
 
 
 

Title:  How do you take your coffee before anesthesia? A randomized controlled crossover study 
comparing gastric emptying with black coffee vs coffee with cream. 
PI: Jessica Yeh, MBBS 
 
Version #: 5 
Date: 12/29/2020Page 3 
 
Background and Rationale 
An important component in the pre-operative patient evaluation is to establish the 
duration of time a patient has been fasting in order to reduce the risk of pulmonary 
aspiration.1 An inadequate fasting time may prompt a change in anesthetic plans or 
result in the delay or cancellation of a case altogether. The risk of anesthetic-related 
pulmonary aspiration is rare due to current anesthetic practices, with the incidence in 
adults cited around 0.05% or less.2, 3, 4 However, the sequelae of aspiration can lead to 
aspiration pneumonitis, prolonged mechanical ventilation and unanticipated intensive 
care.4 
There is no established gastric volume definitively known to increase anesthetic risk of 
aspiration but it has been observed that the gastric volume in most healthy, fasted 
patients can be up to 1.5 ml/kg.5  
Current guidelines recommend a minimum fasting period of 8 hours for fatty foods, 6 
hours for nonhuman milk and non-fatty solid foods, and 2 hours for clear liquids. 
Acceptable examples of clear liquids include water, black coffee or tea, carbonated 
beverages, and fruit juices without pulp.1 However, about 68% of adults in the United 
States consume coffee with add-ins such as cream and/or sugar.6 One study by Larsen 
et al.7 found that adding up to 50% full fat milk to coffee led to no or minimal increase in 
gastric volume measured by Magnetic Resonance Imaging after 2 hours. Hillyard et al.8 
examined the addition of milk to tea and found no difference in gastric emptying times 
using the paracetamol absorption technique and ultrasound measurement of the gastric 
antrum. These studies provide some useful insight on gastric emptying times but are not 
generalizable to beverage consumption in the United States. Typically, the volume of 
coffee consumed is larger than that in Europe and half and half is preferred to milk. Half 
and half is a mixture of milk and cream and has a fat content ranging from 10.5-18% 
compared to 3.25% fat in whole milk.9 Non-dairy coffee creamer is another popular 
addition to coffee, which consists of vegetable oil and corn syrup. This adds both fat and 
sugar to coffee. Therefore, the effects of larger quantities of coffee with the addition of 
high fat content milk products on gastric emptying is unknown. We propose a volunteer 
cross-over study in healthy individuals to assess the effects of milk additives to coffee 
and its effects on gastric emptying. In this study we will compare two separate additions 
to the coffee using half and half and liquid non-dairy coffee creamer.  
 
Objectives 
The primary objective of this study is to compare gastric volume using bedside 
ultrasound in volunteers 2 hours after consumption of black coffee, coffee with half and 
half, and coffee with non-dairy creamer. 
 
 
 

Title:  How do you take your coffee before anesthesia? A randomized controlled crossover study 
comparing gastric emptying with black coffee vs coffee with cream. 
PI: Jessica Yeh, MBBS 
 
Version #: 5 
Date: 12/29/2020Page 4 
 
 
Study Design and Procedures (sometimes called “Methods”) 
This study is a randomized controlled crossover study with 3 arms. One arm is the 
consumption of a 12 ounce (354.8 ml) brewed black coffee. The second is a 12 ounce 
brewed black coffee plus 1 ounce (30 ml) of half and half. The third arm is a 12 ounce 
brewed black coffee plus 1 ounce (30 ml) of non-dairy coffee creamer. Each subject will 
participate in all 3 arms of the study and serve as their own control.  
The order of which arm they will be assigned to will be determined by a computerized 
random number generator which will create a unique sequence from 1 to 3. The number 
1 will be attributed to black coffee without additives. The number 2 will be attributed to 
coffee with half and half and the number 3 will be attributed to coffee with non-dairy 
coffee creamer. For example, a random generation of the sequence 2 1 3 will result in 
the order of arms to be coffee with half and half, black coffee, then coffee with non-dairy 
creamer. The investigator performing the gastric ultrasound will be blind as to which 
drink was consumed. In order to maintain blinding and anonymization during the study, 
each participant will be assigned a unique study number which will not be associated 
with any identifying information. This study number will be associated with the 
randomized number sequence of their coffee arm order and will be used each time the 
participant returns for the next study measurement. 
Each study participant will be instructed to consume nothing by mouth for at least 6 
hours prior to the commencement of the study. An investigator will measure the cross-
section of the gastric antrum using bedside ultrasound with the participant in the right 
lateral decubitus position as a baseline measurement. The participant will then consume 
one of the 3 prepared coffee options. They will be instructed to return 2 hours post 
consumption for the investigator to repeat the gastric antrum cross-section 
measurement with ultrasound. There must be a minimum of 2 days between repeat 
measurements with the other arms of the study. 
 
Study Population 
The study population will be composed of volunteers between the ages of 18 and 65 
and will include 30 total subjects. Recruitment will be via an email to the Department of 
Anesthesia at the University of Arkansas for Medical Sciences asking for volunteers to 
participate in the study. In order to minimize coercion, it will be emphasized that 
participation is voluntary and that there is no reward or negative consequence for 
participating or not. A total of 2 reminder emails will also be sent 1 week apart from 
each other and the initial recruitment email. No recruitment will occur in person to avoid 
potential pressure from a colleague/peer. 
Inclusion Criteria 
● Age between 18-65 
 

Title:  How do you take your coffee before anesthesia? A randomized controlled crossover study 
comparing gastric emptying with black coffee vs coffee with cream. 
PI: Jessica Yeh, MBBS 
 
Version #: 5 
Date: 12/29/2020Page 5 
 
Exclusion Criteria 
● History of diabetes, delayed gastric emptying, previous gastric surgery, lactose 
intolerance, currently pregnant, consumption of solid/liquids in 6 hours prior to 
commencement of ultrasound study 
 
Risks and Benefits 
A risk to study participants is the potential for loss of confidentiality of study data.  
Measures to protect the confidentiality of study data will be implemented as described in 
the Data Handling and Recordkeeping section below. 
There are no direct benefits to participants. 
 
Data Handling and Recordkeeping 
The Principal Investigator will carefully monitor study procedures to protect the safety of 
research subjects, the quality of the data and the integrity of the study. De-identified 
data will be initially recorded on paper on a data collection form then transcribed to 
Excel and kept on UAMS-maintained servers. The paper records will be destroyed by 
confidential shredding. All collected data will be completely anonymized with no way to 
relink it to individual participants. Each participant will be assigned a unique study 
number which will not be associated with any identifying information. This study number 
will be associated with the randomized number sequence of their coffee arm order and 
will be used each time the participant returns for the next study measurement. Only 
investigators will have access to the collected data. At the conclusion of the study, the 
data which is permanently de-identified will be retained for seven years after completion 
of the project. 
 
Data Analysis 
Point of care bedside ultrasound will be used to measure the cross-sectional area of the 
gastric antrum of participants at baseline prior to consumption of coffee and 2 hours 
after consumption of coffee. Three measurements will be taken and recorded each time 
and the mean of these measurements will be used to calculate the predicted gastric 
volume. The difference between gastric volume at baseline and after coffee 
consumption will be compared across all three study arms. We will analyze the data 
using standard statistical methods such as mean, median, mode, standard deviation 
and statistical significance. We will also determine if the gastric volumes after 
consumption of coffee in each arm exceeds 1.5 ml/kg. 
 
 
 

Title:  How do you take your coffee before anesthesia? A randomized controlled crossover study 
comparing gastric emptying with black coffee vs coffee with cream. 
PI: Jessica Yeh, MBBS 
 
Version #: 5 
Date: 12/29/2020Page 6 
 
 
Ethical Considerations  
This study will be conducted in accordance with all applicable government regulations 
and University of Arkansas for Medical Sciences research policies and 
procedures.  This protocol and any amendments will be submitted and approved by the 
UAMS Institutional Review Board (IRB) to conduct the study.   
Study participants will be provided with information outlining the process of the study in 
the recruitment email. They will be fully informed that their participation requires the 
consumption of three different coffee drinks on three separate occasions along with 
ultrasound examinations by one of the study investigators. They will be informed that 
the data collected will be de-identified. This is a minimal risk study and a waiver of 
documentation of consent is requested. The research involves no more than minimal 
risk to the subjects and the research involves no procedures for which written consent is 
normally required outside of the research context. 
 
Dissemination of Data 
Results of this study may be used for presentations, posters, or publications. The 
publications will not contain any identifiable information that could be linked to a 
participant.   
 
References 
1. American Society of Anesthesiologists. Practice Guidelines for Preoperative 
Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary 
Aspiration: Application to Healthy Patients Undergoing Elective Procedures: An 
Updated Report by the American Society of Anesthesiologists Task Force on 
Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk 
of Pulmonary Aspiration. Anesthesiology. 2017;126:376–393. doi: 
https://doi.org/10.1097/ALN.0000000000001452 
 
2. Neillipovitz DT, Crosby ET. No evidence for decreased incidence of aspiration 
after rapid sequence induction. Can J Anaesth. 2007;54:748-764. doi: 
https://doi.org/10.1007/BF03026872 
 
3. Sakai T, Planinsic RM, Quinlan JJ, et al. The incidence and outcome of 
perioperative pulmonary aspiration in a university hospital: a 4-year retrospective 
analysis. Anesth Analg. 2006;103(4):941-947. doi: 
https://doi.org/10.1213/01.ane.0000237296.57941.e7 
 
4. Warner MA, Warner ME, Weber JG. Clinical significance of pulmonary aspiration 
during the perioperative period. Anesthesiology. 1993;78(1):56-62. doi: 
https://doi.org/10.1097/00000542-199301000-00010 

Title:  How do you take your coffee before anesthesia? A randomized controlled crossover study 
comparing gastric emptying with black coffee vs coffee with cream. 
PI: Jessica Yeh, MBBS 
 
Version #: 5 
Date: 12/29/2020Page 7 
 
 
5. Van de Putte P, Perlas A. The link between gastric volume and aspiration risk. In 
search of the Holy Grail? Anaesthesia. 2017;73(3):274-279. doi: 
https://doi.org/10.1111/anae.14164 
 
6. An R, Shi Y. Consumption of coffee and tea with add-ins in relation to daily 
energy, sugar, and fat intake in US adults, 2001-2012. Public Health. 
2017;146:1-3. doi: https://doi.org/10.1016/j.puhe.2016.12.032.  
 
7. Code of Federal Regulations, Title 21, Volume 2, Chapter 1, Part 131 Milk and 
Cream. Electronic Code of Federal Regulations. https://www.ecfr.gov/cgi-bin/text-
idx?SID=b76a4695ab22c8cfa98ea7a934ac0bee&mc=true&node=se21.2.131_11
80&rgn=div8. Published March 15, 1977. Updated October 8, 2020. Accessed 
October 12, 2020. 
 
8. Larsen B, Larsen LP, Sivesgaard K, et al. Black or white coffee before 
anaesthesia? A randomized crossover trial. Eur J Anaesthesiol. 2016;33(6):457-
462. doi: https://doi.org/10.1097/eja.0000000000000457 
 
9. Hillyard S, Cowman S, Ramasundaram R, et al. Does adding milk to tea delay 
gastric emptying? Br J Anaesth. 2014;112(1):66-71. 
 
 
Appendices 
1. Data Collection Form

 
 
 
Study: How do you take your coffee before anesthesia? 
 
 
 
Date: ___________ 
Data Collection Form 
 
 
ID #
Session #
Age
Gender
Height
Weight
BMI
Time coffee 
consumed 
Time US 
exam 
Baseline Antrum CSA
 
Post coffee Antrum CSA