Effect of Pre-operative Carbohydrate Loading on Return of Bowel Function After Reversal of Ileostomy

Ileostomy is a very common operation being performed in both emergent and elective settings. Reversal of an ileostomy, although a relatively straightforward procedure, can be complicated by multiple factors, e.g., post-operative ileus. Incidence of developing post operative ileus after reversal of ileostomy is as high as 30 %. From a patient's point of view, the added morbidity leads to psychological burden whereas for the healthcare system, it adds on to constraints on resources.

Post-operative paralytic ileus is a normal physiological response of the intestines to surgical stress. It is considered pathological if it persists for more than three days and is accompanied by at least two of the following five symptoms: nausea and vomiting, inability to tolerate solid or semi-solid food within the past 24 hours, absence of gas or stool passage for 24 hours, abdominal distension, and radiological signs of ileus. It has been summarized that POI has three phases. The initial phase comprises of neurological processes via effect of beta adrenoreceptor pathways on sympathetic/enteric nervous system due to anesthetic drugs and incision, whereas the second phase comprises of hormonal/inflammatory mechanisms in the walls of intestine, due to manipulation of gut resulting in activation of dendritic cells leading to release of inflammatory cytokines. The permeability of intestinal epithelium also increases during this phase resulting in bacterial translocation further enhancing inflammatory response. Administration of crystalloid fluids during this phase alters the electrolyte especially potassium levels further exacerbating the ileus. This suggests that limiting the use of crystalloids may decrease the incidence of post operative ileus.

Enhanced Recovery After Surgery (ERAS) was introduced in 1999 by Professor Dr. Henrik Kehlet. These programs are now widely implemented in colorectal, gastrointestinal, and other surgical specialties, aiming to shorten hospital stays, promote faster postoperative recovery, and minimize surgical stress. One of the cornerstones of pre-op optimization in ERAS is based on carbohydrate loading. Carbohydrate loading has been shown to improve insulin sensitivity and decrease the incidence of vomiting. Research has shown that carbohydrate loading was associated with reduced time for first flatus compared to controls. Thus one may hypothesize that carbohydrate loading has the potential to reduce the incidence of paralytic ileus.

Rationale:

Ileostomy reversals are commonly performed at Indus Hospital Karachi, especially among young and middle-aged patients. A longer hospital stay can impact productivity by causing a loss of work hours. For a non-profit health network like Indus Hospital, managing resource constraints is crucial. The findings from this study could provide guidelines for peri-operative care that may help reduce hospital stays and alleviate resource challenges.

OBJECTIVES To see effect of pre-operative carbohydrate loading on post-operative return of bowel function after ileostomy reversal.

. OPERATIONAL DEFINITIONS

• Post-operative ileus: diagnosed when at least two of the following five criteria are met: nausea and vomiting, inability to tolerate solid or semi-solid food in the past 24 hours, absence of gas or stool passage for 24 hours, abdominal distension, and radiological signs of ileus.
• Return of bowel function: audible gut sounds through Littmans classic III stethoscope by a surgical resident.

HYPOTHESIS

• Null hypothesis: There is no statistically significant correlation between effect of pre-operative carbohydrate loading and post-operative return of bowel function
• Alternate hypothesis: There is statistically significant correlation between pre-operative carbohydrate loading and post-operative return of bowel function MATERIALS AND METHOD Study design: Randomized Control trial Setting- This study is to be conducted in Department of General Surgery, The Indus Hospital, Karachi Duration- Data collection will be started after permission from Institutional Review Board of The Indus Hospital.

Sample size and sampling technique The sample size was calculated using

X≈ q1 + m + q3 / 3

S≈ q3 - q1/1.35

where Group 1 Median (IQR) was 4.5(2-6),while Group 2 Median (IQR) was 2(0.5-6)

The overall sample size was calculated to be 66. Where:

Group A = 33 (Interventional Arm) Group B = 33 (Placebo Arm)

Sampling Technique: Simple randomized technique

Sample selection

Inclusion criteria

• Age above 18 years
• ASA class 2 and below Exclusion criteria
• Evidence of chronic/active intestinal disease
• Post-operative complication/morbidity besides postoperative ileus
• Failure of conservative management at more than 72 hours Outcomes

• The interval in hours between the end of surgery and:

• Passing of flatus
• Audible gut sounds
• Tolerance to first semi-solid food
• Episodes of Nausea/ vomiting Methodology Patients will be randomly assigned to either the test or control group using a computer-based or envelope method. Those in the test group will receive 200 ml of a carbohydrate-rich drink, while patients in the control group will be given 200 ml of a sugar-free lemon-flavored beverage. To minimize identification, the drinks will be served by staff using opaque jugs on the evening before surgery. An additional 200 ml of the respective drink will be administered by nursing staff at 06:00 on the morning of surgery, ensuring a minimum preoperative fasting period of two hours.

Post-operatively, the interval (in hours) will be noted between the end of surgery and passing of flatus. Patient will be examined for audible gut sounds at 12, 24,36,48,60 and 72 hours post operatively by a 3rd year General surgery (and above) with the help of Littmans stethoscope. Patient will also be assessed for nausea and vomiting at the said hours. He/she will also have their serum electrolytes checked on a daily basis. In case of development of post operative ileus, patient will be managed conservatively i.e Nil per mouth, IV fluids, NG decompression, radiological assessment if needed.

Data collection procedure This study is going to start after approval of synopsis by College of Physician and Surgeon Pakistan (CPSP) and Ethical permission from Institutional Review Board (I.R.B). Informed consent will be taken by patients themselves/next of kin. A questionnaire will be utilized as a data collection tool after informed consent along with investigation reports from patient medical record available in HMIS of The Indus Hospital.

Data analysis procedure Data will be analyzed on SPSS 24. Descriptive statistics will be calculated for all variables and reported as Mean (SD) or Median (IQR) as appropriate (based on the assumptions of normality check by Shapiro-Wilk and Kolmogorov-Smirnov test for continuous variables. Frequency and percentage will be calculated for categorical variables Chi-square/Fisher-Exact test will be applied as appropriate. P -value < 0.05 will be considered statistically significance.

Ethical Considerations

• Data privacy, storage, and anonymization

All study data will be handled under IHHN and CPSP research-data policies. Each participant will be assigned a unique study ID. No names or MR numbers will appear on analysis sheets.

• Storage: Electronic data will be kept in password-protected, hospital-owned computers on the HMIS secure server. Hard-copy consent forms and questionnaires will be locked in the principal investigator's office.
• Access: Only the PI and designated co-investigators will have access.
• Retention/Destruction: Records will be stored for 5 years after study completion and then permanently deleted or shredded.
• Risk disclosure for carbohydrate drink

The carbohydrate drink is a commercially available, ERAS-recommended clear carbohydrate solution. Reported risks are mild GI discomfort, nausea, or rare vomiting.

• Patients with delayed gastric emptying, reflux disease, or aspiration risk will be excluded.
• All administrations will be supervised by nursing and anesthesia teams; any symptoms will be documented and managed promptly.
• Adverse events

All unexpected symptoms (e.g., vomiting, allergic reaction, aspiration, electrolyte imbalance) will be recorded as adverse events (AEs). Serious AEs will be reported to the IHHN IRB within 24 hours and managed as per hospital surgical and anesthesia protocols.

Study Design Observations

• Basis of the questionnaire tool

The questionnaire collects peri-operative and recovery data (flatus passage, gut sounds, diet tolerance, nausea/vomiting, electrolytes) directly reflecting the study objectives and ERAS guidelines.

• It was drafted from established ERAS and Noblett et al. colorectal surgery carbohydrate-loading RCTs and reviewed by the General Surgery faculty at IHHN for content validity.
• A pilot run on initial cases will confirm clarity and reliability.
• Standard clinical procedure for ileostomy reversal at IHHN

The usual pathway includes:

• Pre-operative assessment, routine bowel preparation, overnight fasting, and anesthesia evaluation.
• Elective ileostomy reversal with primary anastomosis under general anesthesia.
• Post-operative monitoring, gradual diet advancement, and discharge after return of bowel function and stable labs.

The trial's only addition to this routine care is the administration of a pre-operative carbohydrate drink (or placebo) two hours before surgery.

DATA COLLECTION INSTRUMENT A questionnaire will be utilized as a data collection tool after informed consent along with investigation reports from patient medical record available in HMIS of The Indus Hospital.

Inclusion criteria

• Age above 18 years
• ASA class 2 and below

Exclusion criteria

• · Evidence of chronic/active intestinal disease

• Post-operative complication/morbidity besides postoperative ileus
• Failure of conservative management at more than 72 hours