C. J. Mitchell

Randomized clinical trial of multimodal optimization and standard perioperative surgical care

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.

The Prevalence of Gut Translocation in Humans

BACKGROUND/AIMS Gut translocation of enteric organisms across the intact intestinal mucosa has been postulated as a potential source of sepsis in susceptible patients. However, little is known of its occurrence or significance in humans. The aim of this study was to determine the prevalence of gut translocation of bacteria in humans and attempt to identify any predisposing factors to its occurrence. METHODS A consecutive series of 267 general surgical patients were examined for evidence of bacterial translocation by bacterial analysis of intestinal serosa and mesenteric lymph nodes taken at the time of surgery. RESULTS Translocation occurred in 10.3% of patients overall. Both aerobic and anaerobic bacteria translocated. Excluding patients with distal intestinal obstruction and those with inflammatory bowel disease in whom translocation was more common, the prevalence was 5%. Neither jaundice, nutritional status, nor total parenteral nutrition predisposed to translocation. Similarly, mucosal atrophy did not predispose to this phenomenon. The development of postoperative septic complications was twice as common in patients with translocation as in those without, but mortality was unaffected. CONCLUSIONS Translocation occurs as a spontaneous event in humans, but its clinical significance remains to be defined.

Enteral versus parenteral nutrition: a pragmatic study ☆

Controversy persists as to the optimal means of providing adjuvant nutritional support. The aim of this study was to compare enteral nutrition (EN) and parenteral nutrition (TPN) in terms of adequacy of nutritional intake, septic and nonseptic morbidity, and mortality. This was a prospective pragmatic study, whereby the route of delivery of nutritional support was determined by the attending clinicians assessment of gastrointestinal function. Patients considered to have inadequate gastrointestinal function were given TPN (group 1), while those deemed to have a functioning gastrointestinal tract received EN (group 2). Patients in whom there was reasonable doubt as to the adequacy of intestinal function were randomized to receive either TPN (group 3) or EN (group 4). The trial setting was a large district general hospital with a dedicated nutrition team. A total of 562 patients were included in the study (331 males; median age 67 y). Gastrointestinal function on entry into the study was considered inadequate in 267 patients who were given TPN (group 1) and adequate in 231 whom received EN (group 2). There was clinical uncertainty about the adequacy of gut function in 64 patients (11.4%) who were randomized to receive either TPN (group 3, 32 patients) or EN (group 4, 32 patients). The incidence of inadequate nutritional intake was significantly higher in group 4 compared with group 3 (78.1% versus 25%, P < 0.001). Complications related to the delivery system and other feed-related morbidity were significantly more frequent in both EN groups compared with the respective TPN groups. EN was associated with a higher overall mortality in both nonrandomized and randomized patients. There were no significant differences observed in the incidences of septic morbidity between patients receiving TPN and those given EN. EN is associated with a higher incidence of inadequate nutritional intake, complications related to the delivery system, and other feed-related morbidity than TPN. There is no evidence from this study to support a difference between the two modalities in terms of septic morbidity. Patients in whom there is reasonable doubt as to the adequacy of gastrointestinal function should be fed by the parenteral route.

Bacterial translocation studied in 927 patients over 13 years.

Bacterial translocation (BT) describes the passage of bacteria from the gastrointestinal tract to normally sterile tissues such as the mesenteric lymph nodes (MLNs) and other internal organs. The clinical and pathophysiological significance of BT remains controversial. This report describes results obtained over a 13‐year period of study.

Oral dietary supplements in pre- and postoperative surgical patients: a prospective and randomized clinical trial.

It has been suggested that the routine provision of oral dietary supplements (ODS) in postoperative surgical patients is of benefit in terms of morbidity and length of hospital stay. The aim of this study was to evaluate the effects of both pre- and postoperative ODS in patients undergoing an elective laparotomy. Patients requiring elective major gastrointestinal surgery were prospectively randomized into one of four groups: Group I received ODS in addition to normal diet both pre- and postoperatively, Group II were given ODS in the preoperative period only, Group III received ODS only in the postoperative period, and Group IV did not receive any supplements. Assessments of nutritional status, voluntary food intake, weight loss, serum albumin, morbidity and mortality, anxiety and depression, and postoperative activity levels were performed, and comparisons made between the groups. One hundred patients were included in the study. The mean daily energy intake from preoperative ODS was 507 +/- 140 kcal, significantly more than the 252 +/- 195 kcal in the postoperative period (P < 0.001). The postoperative voluntary food intake in patients receiving ODS was not significantly different from that in patients receiving normal diet alone (1090 versus 1268 kcal, 46.2 versus 49.1 g protein, P > 0. 05). All groups demonstrated an overall weight loss, with no significant differences between the groups, and there was no demonstrable effect on clinical outcome. At 6 mo postoperatively there were no differences between the study groups in terms of levels of activity. These results suggest that the routine use of perioperative ODS in well-nourished patients undergoing major gastrointestinal surgery confers no clinical or functional benefit.

Alterations in Intestinal Barrier Function Do Not Predispose to Translocation of Enteric Bacteria in Gastroenterologic Patients

Bacterial translocation from the intestinal lumen has been demonstrated in humans. Three mechanisms have been suggested to explain the phenomenon: altered intestinal barrier function, bacterial overgrowth, and impaired host defense. The aim of this study was to determine whether changes in intestinal barrier function assessed by measurement of intestinal permeability and morphology were associated with alteration in bacterial translocation. Intestinal permeability was assessed in 43 patients by the lactulose/L-rhamnose test with a 5-h urine collection. Mucosal atrophy was assessed from the villus height-to-mucosal thickness ratio in small-bowel biopsies. Bacterial translocation was determined by microbiologic analysis of harvested mesenteric lymph nodes. No significant differences were apparent in the incidence of bacterial translocation in patients with normal permeability (5 [23%] of 22 patients translocated) compared with patients with increased permeability (4 [19%] of 21 patients translocated). Similarly, no correlation was apparent between the incidence of bacterial translocation and the index of villus atrophy. The degree of villus atrophy failed to correlate with gastrointestinal permeability. These data suggest that the incidence of bacterial translocation is not related to increased intestinal permeability or mucosal atrophy.

Changes in superior mesenteric artery blood flow after oral, enteral, and parenteral feeding in humans.

Objective:Alterations in splanchnic blood flow cause gut ischemia and may predispose to gut-derived sepsis. Increases in superior mesenteric artery (SMA) blood flow occur follow the oral ingestion of food, but the effects of enteral nutrition (EN) on splanchnic perfusion are poorly defined and those of parenteral nutrition (PN) are unknown in humans. The aim of this study was to investigate changes in SMA flow in healthy controls and patients receiving adjuvant nutrition. Design:Qualitative before-after study. Setting:Intensive care and general wards at Scarborough Hospital, Scarborough, United Kingdom. Patients:Fourteen healthy volunteers and 20 consecutive hemodynamically stable patients receiving adjuvant nutrition. Interventions:Oral, EN, or PN after an overnight fast. Measurements and Main Results:Duplex ultrasonography was used to assess SMA flow after an overnight fast. Subjects were then rescanned 3 hrs later after commencement of the appropriate test feed so that postprandial flows could be determined. Of the 20 patients recruited, 10 were receiving EN (120 kcal) and 10 PN (175 kcal). Of the 14 volunteers, three received no feed before their second scan (controls), six received an oral meal (530 kcal), and five received EN (120 kcal). Changes in SMA flow within groups were assessed. The control (fasting) volunteers showed no change between the two scans (p = 1.000). All subjects fed intraluminally demonstrated significant increases in postprandial SMA blood flow. Conversely, all patients fed parenterally showed decreased postprandial SMA flows with a median (interquartile range) fasting SMA flow of 14.5 (4.8–24.8) mL/sec, which decreased to 6.1 (2.4–9.2) mL/sec postprandially (p = 0.013). Conclusions:Splanchnic flow is modulated by the route of feeding. The clinical significance of these findings requires further investigation as they may be important in the management of the critically ill patient, particularly in those with cardiovascular instability or any patient predisposed to gut ischemia.

Prospective study of the aetiology of infusion phlebitis and line failure during peripheral parenteral nutrition

Four techniques of administering peripheral parenteral nutrition (PPN) were examined prospectively to investigate the role of mechanical trauma in the development of infusion phlebitis. Patients in group 1 (n = 15) were fed via a standard 18-G Teflon cannula which was removed on completion of the infusion and was rotated to the contralateral arm every day. Group 2 patients (n = 15) had a similar catheter sited in each forearm simultaneously, with rotation of the side of infusion each day. Patients in group 3 (n = 17) had a 15-cm Silastic rubber catheter inserted into a forearm vein and a standard cannula sited in the contralateral forearm, with alternation of infusion each day. Those in group 4 (n = 13) had a fine-bore 23-G silicone catheter sited in one arm only. Patients in groups 1, 2 and 3 were fed over 12-h cycles and those in group 4 for a 24-h continuous cycle. A total of 408 patient-days of PPN were given. Mean duration of PPN in groups 1-4 was 7.5, 9, 5.5 and 5 days respectively. Infusion phlebitis was not recorded in patients who had a daily change of cannula (group 1), but occurred in four patients in group 2, eight in group 3 and eight in group 4. Phlebitis scores were 0, 9, 15 and 12 for groups 1-4 respectively. Severe phlebitis and line occlusion occurred more frequently in patients with a 15-cm catheter (group 3) and in those fed continuously over 24 h (group 4). These results suggest that mechanical trauma is an important factor in the aetiology of infusion phlebitis. This can be minimized by reducing the time for which the vein wall is exposed to nutrient infusion and by reducing the amount of prosthetic material within the vein.

Gastric colonization predisposes to septic morbidity in surgical patients: A prospective study

OBJECTIVE Several previous studies have suggested that pathological colonization of the proximal gastrointestinal (GI) tract may be associated with septic morbidity. However, the prevalence of this in surgical patients is unknown and there is little information on factors that might predispose to this phenomenon. The aim of this study was to assess the preoperative variables that are associated with pathological colonization of the proximal GI tract in surgical patients. METHODS Nasogastric aspirates were obtained from 502 surgical patients to identify abnormal colonization. Several preoperative variables were tested to identify association with pathological colonization of the proximal GI tract. Postoperative septic morbidity was recorded prospectively in all patients. RESULTS Enterobacteriaceae were identified in 78 of 502 patients (15.5%), 124 of 502 (24.7%) had multiple organisms, and 157 of 502 (31.3%) had Candida in the nasogastric aspirates. Age >70 y and emergency surgery were associated with presence of Enterobacteriaceae. Age >70 y was also associated with the presence of multiple organisms (with or without Enterobacteriaceae). Colonization with Enterobacteriaceae or presence of multiple organisms in the proximal GI tract was associated with postoperative septic morbidity. Preoperative total parenteral nutrition was associated with Candida colonization in the upper GI tract, but not with sepsis. CONCLUSION Pathological colonization of the proximal GI tract with Enterobacteriaceae or multiple organisms is associated with increased incidence of postoperative sepsis. Age >70 y and emergency surgery were the two preoperative variables associated with pathological colonization in surgical patients. Preoperative total parenteral nutrition is associated with fungal colonization but this is not associated with septic morbidity.

Could pre-mortem computerised tomography scans reduce the need for coroner's post-mortem examinations?

INTRODUCTION Post-mortem examinations may result in considerable distress to the bereaved family. This audit was undertaken to examine whether computerised tomography (CT) scanning prior to death might reduce the need for post-mortems without compromising the accuracy of recording the cause of death. SUBJECTS AND METHODS The case notes of 100 consecutive patients who had a coroners post-mortem, because the cause of death was unknown, were reviewed by four senior clinicians. Along with the likely cause of death, the clinicians gave their opinion as to whether a CT scan would have enabled certification of death without the need for a post-mortem. Concordance between the post-mortem findings and the clinical events surrounding death was explored. RESULTS It would have been possible to perform a pre-mortem CT scan on 90 of the 100 patients. A pre-mortem CT scan would have given the cause of death in 59 (66%) of these. In 30 patients, the cause of death established by the post-mortem was at variance with the clinical events surrounding death and clinically relevant information, such as recent surgery, was not recorded on the death certificates of 26 patients. CONCLUSIONS The use of a pre-mortem CT scan and involvement of senior clinicians in the process of establishing cause of death will improve the accuracy and may obviate the need for a post-mortem in some patients. However, if a post-mortem is needed, the clinical notes should always be available for the pathologists and a senior member of the patients team should attend the post-mortem to help accurate death certification.