Effect of thoracic epidural anaesthesia on splanchnic blood flow.

BACKGROUND: Thoracic epidural anaesthesia (TEA) is used widely in colorectal surgery. However, there is increasing concern that epidurals are associated with postoperative hypotension, mediating a potential reduction in splanchnic flow. The aim was to review the literature on the effects of TEA on splanchnic blood flow. METHODS: PubMed and Cochrane databases were searched. Search terms used were: English language, 'thoracic epidural splanchnic flow', 'thoracic epidural gut blood flow', 'thoracic epidural intestinal blood flow' and 'thoracic epidural colonic blood flow'. Abstracts were reviewed by two independent researchers and irrelevant studies excluded. The full text of the remaining articles was then retrieved. RESULTS: Twenty-two abstracts were reviewed and three excluded. Nineteen papers were reviewed in full and seven irrelevant articles excluded. Five human studies investigated the effects of TEA on splanchnic flow. Two studies measured splanchnic flow directly and found an epidural-mediated fall in flow, unresponsive to intravenous fluids and requiring vasopressors or inotropes to restore baseline flow. The remaining three studies had inconsistent findings and haemodynamic stability was maintained. The seven animal studies identified were heterogeneous in both methodology and findings. Three suggested a protective role for thoracic epidurals in septic shock and pancreatitis. CONCLUSION: These findings are inconsistent; however, the two studies that investigated the effects of vasoconstrictors on splanchnic blood flow directly both found a significant epidural-mediated reduction in splanchnic blood flow that was unresponsive to fluid therapy.

Guidelines for perioperative care in elective colonic surgery: Enhanced Recovery After Surgery (ERAS®) Society recommendations.

BACKGROUND: This review aims to present a consensus for optimal perioperative care in colonic surgery and to provide graded recommendations for items for an evidenced-based enhanced perioperative protocol. METHODS: Studies were selected with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohorts. For each item of the perioperative treatment pathway, available English-language literature was examined, reviewed and graded. A consensus recommendation was reached after critical appraisal of the literature by the group. RESULTS: For most of the protocol items, recommendations are based on good-quality trials or meta-analyses of good-quality trials (quality of evidence and recommendations according to the GRADE system). CONCLUSIONS: Based on the evidence available for each item of the multimodal perioperative-care pathway, the Enhanced Recovery After Surgery (ERAS) Society, International Association for Surgical Metabolism and Nutrition (IASMEN) and European Society for Clinical Nutrition and Metabolism (ESPEN) present a comprehensive evidence-based consensus review of perioperative care for colonic surgery.

An investigation into the effect of a probiotic on gut immune function in surgical patients.

BACKGROUND: The gut-associated lymphoid tissue (GALT) is an important component of the gut barrier. We have previously demonstrated a significant increase in various parameters of gut immune function in association with bacterial translocation. Animal studies have suggested that the probiotic Lactobacillus plantarum 299v improves the immunological status of the intestinal mucosa. The aim of this study was to determine whether the same is true in humans. METHOD: This was a prospective randomised controlled study, in which immunohistochemical techniques were used to measure the concentrations of plasma cells, IgA positive cells and IgM positive cells in the lamina propria, together with the concentrations of IgA and IgM at the mucosal surface in specimens of normal small bowel obtained from patients undergoing elective abdominal surgery who had consumed an oral preparation containing the probiotic Lactobacillus plantarum 299v (ProViva) during the immediate preoperative period. These were compared with similar specimens obtained from control subjects who did not receive the probiotic. RESULTS: A total of 22 patients were studied (probiotic group n = 11, control group n = 11). The median volume of ProViva consumed was 3250 ml (range 2100-9000 ml), for a median duration of 9 days (range 5-18 days). There were no significant differences between the probiotic and control groups in terms of concentrations of plasma cells, IgA positive cells or IgM positive cells in the lamina propria. There was a significantly higher concentration of IgM at the mucosal surface in the control group (P = 0.02, Fishers Exact test mid P), but no difference in terms of IgA. CONCLUSIONS: The increase in IgA observed in the intestinal mucosa in response to probiotics in animal studies does not occur in humans. The significance of the increase in IgM at the mucosal surface in the controls is unclear.

Randomised clinical trial of synbiotic therapy in elective surgical patients.

BACKGROUND: It is possible to manipulate the composition of the gastrointestinal microflora by administration of pre- and probiotics. This may help to preserve gut barrier function and reduce the incidence of septic morbidity. AIMS: To assess the effects of a combination of pre- and probiotics (synbiotic) on bacterial translocation, gastric colonisation, systemic inflammation, and septic morbidity in elective surgical patients. PATIENTS: Patients were enrolled two weeks prior to elective abdominal surgery. Seventy two patients were randomised to the synbiotic group and 65 to the placebo group. Patients were well matched regarding age and sex distribution, diagnoses, and POSSUM scores. METHODS: Patients in the synbiotic group received a two week preoperative course of Lactobacillus acidophilus La5, Bifidobacterium lactis Bb-12, Streptococcus thermophilus, and Lactobacillus bulgaricus, together with the prebiotic oligofructose. Patients in the placebo group received placebo capsules and sucrose powder. At surgery, a nasogastric aspirate, mesenteric lymph node, and scrapings of the terminal ileum were harvested for microbiological analysis. Serum was collected preoperatively and on postoperative days 1 and 7 for measurement of C reactive protein, interleukin 6, and antiendotoxin antibodies. Septic morbidity and mortality were recorded. RESULTS: There were no significant differences between the synbiotic and control groups in bacterial translocation (12.1% v 10.7%; p = 0.808, chi(2)), gastric colonisation (41% v 44%; p = 0.719), systemic inflammation, or septic complications (32% v 31%; p = 0.882). CONCLUSIONS: In this study, synbiotics had no measurable effect on gut barrier function in elective surgical patients. Further studies investigating the place of pre- and probiotics in clinical practice are required.

Randomized clinical trial of multimodal optimization and standard perioperative surgical care.

BACKGROUND: Multimodal optimization of surgical care has been associated with reduced hospital stay and improved physical function. The aim of this randomized trial was to compare multimodal optimization with standard care in patients undergoing colonic resection. METHODS: Twenty-five patients requiring elective right or left hemicolectomy were randomized to receive a ten-point optimization programme (14 patients) or conventional care (11). The groups were similar in terms of age (64 versus 68 years), male : female sex ratio (6 : 8 versus 5 : 6) and Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) score (both 26). Outcome measures were recorded before operation and on postoperative days 1, 7 and 30. They included hand grip strength, lung spirometry, and pain and fatigue scores. Further outcome measures included time to achieve a predetermined mobilization target, time to resumption of normal diet, and length of stay. RESULTS: Optimization was associated with maintained grip strength, earlier mobilization (46 versus 69 h; P = 0.043), and significantly lower pain and fatigue scores. Patients in the optimization group tolerated a regular hospital diet significantly earlier than controls (48 versus 76 h; P < 0.001). Optimization significantly reduced the median length of hospital stay (3 versus 7 days; P = 0.002). CONCLUSION: Optimization of surgical care significantly improved patients' physical and psychological function in the early postoperative period and facilitated early hospital discharge.

A prospective randomised study of the probiotic Lactobacillus plantarum 299V on indices of gut barrier function in elective surgical patients.

BACKGROUND: Bacterial translocation occurs in surgical patients and may predispose to postoperative septic morbidity. Many factors are thought to influence the prevalence of bacterial translocation, one of which is the composition of the gut microflora. The aim of this prospective and randomised study was to assess the effect of the probiotic Lactobacillus plantarum 299v on the incidence of bacterial translocation, gastric colonisation, and septic complications in elective surgical patients. METHODS: Patients undergoing elective major abdominal surgery were randomised to either a treatment or control group. The treatment group received an oral preparation containing Lactobacillus plantarum 299v (Proviva) for at least one week preoperatively and also in the postoperative period. Bacterial translocation was determined by culture of a mesenteric lymph node and serosal scraping obtained at laparotomy. Gastric colonisation was assessed by microbiological culture of nasogastric aspirates. All postoperative septic complications were recorded. RESULTS: A total of 129 patients completed the study (probiotic group n=64). There was no significant difference between the two groups in terms of bacterial translocation (12% v 12%; p=0.82), gastric colonisation with enteric organisms (11% v 17%; p=0.42), or septic morbidity (13% v 15%; p=0.74). CONCLUSIONS: Administration of Lactobacillus plantarum 299v in elective surgical patients does not influence the rate of bacterial translocation, gastric colonisation, or incidence of postoperative septic morbidity.

Gastric colonisation, intestinal permeability and septic morbidity in acute pancreatitis.

INTRODUCTION: Bacterial translocation (BT) may represent an important cause of septic morbidity in patients with acute pancreatitis. We have previously demonstrated an association between BT, septic morbidity and colonisation of the proximal GI tract. Alterations in intestinal permeability (IP) may also predispose to BT. The aim of this study was to assess the extent of gastric colonisation, measure IP in patients with acute pancreatitis and relate these to both disease severity and septic complications. METHODS: Gastric colonisation was determined by culturing a sample of nasogastric aspirate, and IP was measured using a dual sugar probe technique (lactulose/rhamnose test). Disease severity was assessed according to the modified Glasgow (Imrie) criteria. All septic complications were recorded prospectively. RESULTS: A total of 59 patients were studied (M:F ratio 32:27, median age 66 years, range 18-89), 24 (31%) of whom had severe disease. A nasogastric aspirate was obtained in 56 patients. There was a significantly higher incidence of colonisation with potentially pathogenic enteric bacteria in patients with severe disease compared to those with mild disease (57 vs. 6%, p < 0.001). Septic morbidity occurred in 29% of severe patients and 11% mild patients (p = 0.17). 33% of patients colonised with enteric organisms developed sepsis, compared to 16% with no enteric bacteria in the NG aspirate (p = 0.34). Enteric bacteria caused 77% of the septic complications. Intestinal permeability was neither associated with disease severity nor was it predictive of septic morbidity. CONCLUSIONS: There is significantly higher incidence of gastric colonisation with enteric bacteria in patients with severe acute pancreatitis, but no difference in IP. Enteric bacteria were implicated in the majority of septic complications. These findings support the gut origin of sepsis hypothesis in acute pancreatitis.