Ask an answerable question (PICO)：
The prevalence of colorectal cancer remains elevated, with surgical excision being the primary therapeutic modality. Subsequent to intestinal procedures, it becomes imperative to monitor gastrointestinal motility, sustained flatus, the intestine's tolerance to a conventional diet, potential leakage at the site of intestinal anastomosis, and the progression of postoperative wound healing, among other factors. Frequently, the author is approached by anxious patients or their families, inquiring about the implications of the timing of resumption of food and beverage intake postoperatively on their convalescence. Are there any detrimental sequelae associated with post-surgical consumption? These inquiries are pervasive. Consequently, driven by this premise, our aim is to conduct an evidenced-based review into the efficacy of initiating enteral nutrition within 24 hours post-surgery on enhancing gastrointestinal recuperation and reducing the duration of hospital stay among patients undergoing colorectal procedures, thereby augmenting the postoperative patient care quality.
The Method and Analysis of Literature Review：
Utilizing the evidence-based PICO framework: Population: Patients undergoing colorectal surgery. Keywords and MeSH terms include "colorectal surgery," "lower intestinal surgery," and "lower gastrointestinal surgery." Intervention: Early oral intake or gastrointestinal tract diets. Comparison: Standard postoperative care or delayed oral intake. Outcome: the length of hospital stay. Search Strategy: Electronic databases, namely PubMed and Cochrane, were meticulously searched employing the aforementioned keywords and MeSH terms. Boolean operators were strategically utilized: "OR" for amalgamation and "AND" for intersection of terms. Search Limitations: The search was meticulously narrowed to include only human studies, systematic reviews, and articles written in English. Furthermore, the time frame was specified from 2017 to May 2022. Inclusion Criteria: Papers that aligned with the key terms and imposed constraints were incorporated. Exclusion Criteria: Excluded were studies pertaining to unrelated surgeries, those devoid of interventional measures, non-human studies, and those not emphasizing oral feeding. Following this rigorous approach, a total of three articles were deemed fitting for the systematic literature review.
Critical Appraisal：
The systematic review was appraised using the Systematic Review Appraisal Sheet from CEBM University of Oxford. Among the three articles, precise topic delineation was observed in 31%, exhaustive search methodologies in 10%, and appropriate inclusion and exclusion criterion in 50%. However, a substantial risk of bias in research quality was prevalent, accounting for 50%. Notably, all manuscripts exhibited heterogeneity as denoted by I2 and opted for a random-effects model; their evaluations uniformly yielded affirmative "YES" outcomes. Moreover, based on the Oxford Center for Evidence-Based Medicine's grading scale, all three articles were designated a Level 1 evidence grade.
The first article integrated 7 RCTs with a total of 748 people. Those allocated to the experimental group and administered early enteral nutrition manifested a reduction in hospitalization duration compared to their counterparts who observed conventional postoperative fasting (MD -0.89; 95% CI -1.22 ~ -0.57; I2= 78%). The second article integrates 5 RCTs with a total of 785 people. The experimental group provided early enteral nutrition compared with traditional postoperative fasting, and the length of hospitalization was reduced (MD -2.33; 95% CI -4.12 ~ -0.54; I2= 0 %). The third article integrated 16 RCTs with a total of 1346 people. Those in the experimental group who received early enteral nutrition within 24 hours after surgery had fewer days of hospitalization than those who fasted after traditional surgery (MD -1.95; 95% CI -2.99 ~ -0.91; I2= 81%). The heterogeneity in the literature is high, due to the inclusion of studies on high-risk surgeries. From this, it is known that early enteral nutrition can reduce postoperative hospitalization days in colorectal surgery patients, but there is no significant difference in comorbidities, nausea, vomiting, and mortality.
Results, Conclusions and Recommendations：
Conventionally, clinicians recommend that patients wait until they have flatulence after surgery and start drinking water. Nutritional intake in evidence-based literature starts with a full liquid diet within 24 hours after surgery. The patient's tolerance is observed and a gradual diet to solid food is continued. This can reduce the number of days in hospital. According to the results of two studies of the three systematic reviews in this article, there was an increase in vomiting, while the others showed no significant difference in comorbidities, nausea and vomiting, and mortality. Any form of early enteral nutrition within 24 hours on the day after surgery can stimulate intestinal peristalsis, restore intestinal function as early as possible, shorten the time for gas and defecation, and enable recovery with the minimum number of hospitalization days, which can reduce unnecessary medical costs. It is recommended that high-quality research designs be used to further explore the advantages and disadvantages of early enteral nutrition in the future.
