The Research On The Relationship Between The Perioperative Insulin Resistance And Postoperative Ileus After Abdominal Surgery For Gastrointestinal Cancers

ObjectivePostoperative ileus (POI) is a common adverse stress reaction after most abdominalsurgery. Secondary POI sometimes may also cause anastomotic leakage, abscesses, peritonitis,etc. There are many influence factors for the occurrence of POI, the control of which hasbecome the focus on the surgery increasingly. Recently the discussion of mechanism,prevention and treatment for POI is also reported frequently. Insulin resistance (IR) is anothercommon stress reaction during the perioperative period and also the focus of research attentionsrecently. The postoperative IR will cause many adverse reactions such as increased metabolism,wound healing bad and increased rates of infection, etc, which seriously disrupt the homeostasis.Some literature about clinical studies which was reported at home and abroad recently, mostlyfrom the perspective of prevention and treatment of POI, sought best methods to reduceperioperative surgical stress, the POI time, and recovery time, and then improve the prognosisfor patients. Now it has been demonstrated that many methods can reduce the occurrence andduration of POI. When Fast Track Surgery (FTS) appears POI time can be reduced to24h to48h after abdominal operation. Now the report is very little about whether there is relationshipbetween perioperative IR and POI after abdominal surgery for gastrointestinal cancers. Alongwith Homeostasis Model Assessment-2(HOMA-2) is used in clinical practice, it is very easy todetect IR index by software. We selected33patients with abdominal surgery forgastrointestinal cancers as the object, and try to show that the perioperative IR can delay therecovery time of POI by analysing the relationship between them, which provide a theoreticalbasis for the positive treatment after operation, improving prognosis and other research onprevention and treatment for POI. MethodsThis study was conducted between March2011and December2011at Guangzhou RedCross Hospital. And in this study,33patients (20males,13females) were selected as the object,who were weighing from35to85kg and aged from39to84years old without Endocrine andmetabolic diseases. And the patients selected as the object were all scheduled to undergoabdominal surgery for gastrointestinal cancers in our hospital. Their preoperative diagnosis hasbeen clear by gastroscopy or colonoscopy, pathology, hematology, imageology and so on. Wealso confirmed their postoperative diagnosis by pathology. A posttest-only randomized controltrial design was chosen with measurement taken each day after abdominal surgery forgastrointestinal cancers until passage of first flatus and first defecate. A pretest randomized trialwas not plausible owing to the subjects having to undergo surgery prior to measurement of thedependent variables: postoperative IR index, insulin, blood glucose and C-peptide, time topostoperative bowel sounds, first flatus and first defecate. The study was approved by theinstitutional review board, and informed consent was obtained from each patient prior toenrollment. According to the physiological and operative severity part of POSSUM system, weselecte the latest available laboratory data before surgery to evaluate the preoperative andsurgical conditions for each patient. And use the software downloaded from the foreign net tocalculate the perioperative IR index for each object. According to the changes of IR index, wecalculate the absolute value of IR index difference(|IRafter surgery-IRbefore surgery|), and order themfrom small to large. Select P50=0.60as the cut off value to divide all objects into two groups:take the smaller into A group (16) and the larger into B group (17). For each patient we need torecord time to postoperative bowel sounds, first flatus and first defecate, postoperativecomplications.Results①There was no significant difference between the two groups in general informationbefore surgery, operative severity score (OSS), operation time, blood loss and incision length(P>0.05). But the amount of average blood loss in group B was obviously more than that ingroup A.②Compared to the perioperative IR index of all patients, the ones after surgery and in postoperative first and third day were all significantly higher than the preoperative(P<0.05).And in the seventh day after surgery the IR index of patients were similar as the preoperativelevel(P>0.05).③There was significant difference between the two groups in time to firstflatus(P<0.05). Compared to A group, B group has no significant difference in time topostoperative bowel sounds and first defecate by anus and incidence of postoperativecomplications(P>0.05), but for average B group was later than A group on all of the aboverecovery time.④Select the perioperative and surgery influencing factors as independentvariables, and the changes of perioperative IR index as dependent variable to do a Logisticregression analysis. The result shows that the blood loss volume enters into the equation,indicating that the blood loss volume is the main factor affecting the change of perioperative IRindex.⑤Select the perioperative and surgery influencing factors as independent variables, andthe time to first flatus as dependent variables to do a Logistic regression analysis again. Theresult shows that the age, stature, PS score and the changes of perioperative IR index enters intothe equation, indicating that preoperative physical condition and the different changes ofperioperative IR index caused by surgery between the both groups are the main factors to delaythe POI recovery time for patients.ConclusionThe more blood loss volume during the operation is the main factor for the large changeof perioperative insulin resistance index after abdominal surgery for gastrointestinal cancers,which is one of the main factors for the delay of postoperative ileus.