Can Coffee/Caffeine Improve Post-Operative Gastrointestinal Recovery? A Vanguard Randomized Controlled Trial

Disruption of the normal gastrointestinal (GI) motility is a well-known consequence of major surgery. The pathophysiology behind this phenomenon is not fully understood but involves the autonomic nervous system as well as a systemic stress response to surgery. A number of factors interfere with GI motor activity, such as the direct manipulation of intestines during surgery and the use of opioid analgesia. Post-operative ileus (POI) refers to a delay in regaining GI motility beyond the anticipated normal duration of time. Signs and symptoms include nausea, vomiting, abdominal distention, the absence of flatus or stool in the preceding 24 hours, and/or an inability to tolerate oral intake. The incidence of POI in abdominal surgery is estimated to be approximately 10%-30%. Beyond increased patient discomfort and distress, the development of POI is associated with increased healthcare costs.

Coffee is a popular beverage: two thirds of Canadians are coffee drinkers, averaging approximately 3.2 cups per day. Coffee is composed of hundreds of chemicals, many with demonstrated pharmacologic effects. The most well-known of these compounds is caffeine, known to exert a stimulatory effect on the cardiovascular and nervous system. A recent systematic review of 7 randomized controlled trials (N=606 colorectal and gynecology surgical patients) determined that the consumption of coffee reduced the time of several measures of GI recovery, such as time to tolerance of food, without any increased rate of complications or adverse events although overall, the evidence was graded as low to moderate certainty, and further confirmatory studies are needed. In this trial, patients aged 18 years or higher who undergo laparoscopic or open abdominal surgery, with an estimated length of stay > 24 hours will be randomized to receive approximately one cup of either coffee, decaffeinated coffee, or warm water, three times daily. This trial will be conducted under the IMPACTS (Innovative, Multicentre, Patient-centred Approach to Clinical Trials in Surgery) program umbrella and will follow IMPACTS methodology. For the Vanguard trial, the aim is to determine the feasibility of conducting a definitive trial. Future outcomes of interest include: time to first flatus, time to first bowel movement, placement of an NG tube, length of stay in hospital, 30-day mortality, and 30-day postoperative complications.