Endotoxin temporarily impairs canine colonic absorption of water and sodium

Diarrhea is a common manifestation of sepsis. We hypothesized that endotoxin may impair colonic absorption of water and electrolytes, an effect which may be related to altered liquid transit in the colon. Five dogs underwent construction of 50-cm colonic Thiry-Vella fistulas (TVF). Following recovery, absorption studies were performed by perfusing the TVF with an isotonic solution at 2.9 ml/min containing polyethylene glycol (5 g/L). Fasting and postprandial colonic absorption of water, electrolytes, and glucose were determined. Liquid transit was assessed by bolus of a nonabsorbable marker (PSP) instilled into the proximal end of the TVF. Following completion of the baseline studies, each dog was given a single dose of Escherichia coli lipopolysaccharide 200 micrograms/kg i.v. and the studies were repeated daily for the next 3 days. Following endotoxin bolus, colonic absorption of water and sodium were decreased during fasting, while postprandial colonic absorption of water was also decreased. Colonic absorption of water and sodium returned to baseline values on postendotoxin day 2. Colonic secretion of potassium was decreased on postendotoxin days 1 and 3 in both the fasting and the fed periods. Fasting and postprandial liquid transit was also rapid on postendotoxin day 1, which correlated with the decreased absorption seen on that day. Liquid transit returned to baseline values on postendotoxin day 2. We conclude that endotoxin temporarily impairs postprandial colonic absorption, which may be due to the rapid liquid transit that occurs. These effects may contribute to the diarrhea seen during and after septic episodes.

Gastric contractions, secretions and injury in cold restraint

The clinical syndrome of stress ulceration has been studied for years using rodent cold restraint stress models, although the pathogenesis of the characteristic focal gastric mucosal lesions produced in these models has been controversial. We used gastric strain gauges to characterize fully the gastric motility effects of a 4-h cold restraint protocol, and we determined the relationship of variations in gastric contents and in gastric contractions to the amount of gastric mucosal injury. Additionally, we examined rat stomachs histologically, and determined the location of focal haemorrhagic mucosal lesions on the mucosal rugae. We found a consistent relationship between force of gastric contractions and gastric mucosal injury, and also a relationship between the initial duration of contractions during restraint and ultimate mucosal injury. Volume, acidity and mucus in the gastric contents were unrelated to mucosal injury. The majority (91%) of the mucosal lesions had some relationship to a rugal fold, with 59% of all lesions at the base of a rugal fold. Thus, the mechanical forces of gastric hypercontractility may contribute to the gastric mucosal injury of rodent cold restraint models.

A decade of change in obesity surgery. National Bariatric Surgery Registry (NBSR) Contributors

BACKGROUND

The International (formerly National) Bariatric Surgery Registry began collecting data in January 1986. The aim of this study was to examine changes in the practice of surgical treatment of severe obesity that occurred during the decade of 1986 through 1995, as observed in the IBSR data.

METHODS

All data submitted to the IBSR during the decade were transferred to the IBM mainframe computer for analysis. Characteristics of operative type populations were compared over time using analysis of variance (ANOVA) for age, body mass index (BMI), operative weight and Chi-square (chi2) test for gender.

RESULTS

There has been a steady increase over the decade in mean patient weight. The operations used have changed from predominantly 'simple' operations to more frequent use of 'complex' operations. Within the categories of 'simple' and 'complex', an increase in the variety of operations occurred. As a group, patients with 'simple' operations have been heavier, more often male and public pay patients than those who have undergone 'complex' operations. One year weight loss was greater for Roux-en-Y gastric bypass (RGB) than vertical banded gastroplasty (VBG), but follow-up rates were too low to study the relative merits of the operations used. The reported incidence of operative mortality and serious complications (leak with peritonitis, abscess and pulmonary embolism) remained low.

CONCLUSIONS

These observations and their implications can be summarized in three statements which relate to action for improved patient care in the beginning of the new century: (1) increasing weight of candidates for surgical treatment during this decade indicates the need for earlier use of operative treatment before irreversible complications of obesity can develop; (2) low risk of obesity surgery, decreasing postoperative hospital stay, and early weight control support the continued and increased use of surgical treatment; (3) continued widespread use of both 'simple' and 'complex' operations with increased modifications of standard RGB and VBG procedures emphasizes the need for standardized long-term data and analyses regarding both weight control and postoperative side-effects.

The role of antioxidant enzymes in the control of opossum sphincter of Oddi motility

Superoxide rapidly oxidizes nitric oxide (NO) to form peroxynitrite, thus terminating the biological activity of NO. The aims of our study were to determine if superoxide alters the motor function of the sphincter of Oddi and to localize the antioxidant enzymes in the sphincter of Oddi. Immunostaining was performed and enzyme activities were measured in the sphincter of Oddi. In physiological experiments, force-displacement transducers recorded tension in the spontaneously contracting sphincter of Oddi and after electrical field stimulation (EFS) of precontracted sphincter of Oddi. Superoxide was generated by the addition of xanthine with xanthine oxidase, superoxide radicals were scavenged by the addition of superoxide dismutase (SOD), and catalase or SOD was inhibited by diethyldithiocarbamic acid. Immunostaining demonstrated SOD and catalase immunoreactivity in ganglia situated at the serosal surface of the circular muscle. Total SOD activity was 202 +/- 12 U/mg. Generation of superoxide or inhibition of SOD increased the contractile frequency and decreased relaxation after EFS. We conclude that superoxide alters sphincter of Oddi motor function, and the presence of superoxide scavenging enzymes in enteric plexuses suggests that they may regulate sphincter of Oddi neuromuscular function by clearing endogenous superoxide.

Endotoxin temporarily impairs canine jejunal absorption of water, electrolytes, and glucose

Enteral feeding during and after episodes of sepsis may be beneficial. The aim of our study was to determine the effects of a single sublethal dose of endotoxin on canine jejunal absorption. Following a 240 kcal liquid meal, absorption studies were performed in eight dogs with 75 cm jejunal Thiry-Vella fistulas. These fistulas were perfused with an isotonic solution containing polyethylene glycol to calculate absorption. Each dog was then given a single dose of Escherichia coli lipopolysaccharide, 200 microg/kg intravenously, and the studies were repeated for the next 3 days. Following endotoxin bolus infusion, net absorption of water, electrolytes, and glucose was decreased for 2 days and returned to baseline values on postendotoxin day 3. A single sublethal dose of endotoxin temporarily impairs canine jejunal absorption. Although enteral feeding may be advantageous, jejunal absorption may be temporarily impaired following an episode of endotoxemia.

Pathophysiology of adynamic ileus

We hypothesized that the inhibitory neurotransmitters nitric oxide (NO) and vasoactive intestinal peptide (VIP) may play a role in the disrupted gastrointestinal motility of endotoxemia. Strain gauge transducers on the stomach and small intestine of dogs determined interdigestive gastrointestinal motility. Tissue levels of NO synthase and VIP and serum levels of nitrite/nitrate (NO(2)-/NO(3)-) and VIP were measured. Following completion of the baseline studies, dogs were given a single dose of E. coli lipopolysaccharide, 200 microg/kg intravenously, and the studies were repeated for the next three days. Following endotoxin bolus, the migrating motor complex (MMC) was delayed for two days while serum VIP was increased on postendotoxin day 1 and serum NO(2)-/NO(3)- was increased on postendotoxin day 2. There were no changes in gut smooth muscle levels of NO synthase or VIP. We conclude that a single, sublethal dose of endotoxin results in prolongation of the MMC with distinct but independent increases in serum levels of VIP and NO(2)-/NO(3)-.

Beyond the hospital walls. Saint Raphael's vision of care includes jobs, home loans, and a reading room

Saint Raphael Health System is based in inner-city New Haven, CT, an area plagued by poverty, unemployment, and high infant mortality. Its leaders have long realized that healthcare involves more than curing diseases and patching wounds. Thus, in 1922, they launched Saint Raphael's Neighborhood Plan, which has five main components. The Neighborhood Reading Room, in a police substation, gives children a place to read, do homework, and get off the streets. The Neighborhood Home Ownership program helps Saint Raphael employees buy homes in the neighborhood. The Neighborhood Scholarships program gives eligible residents an opportunity to study full time at a state university or vocational school. The Neighborhood Career Counseling and Job Skills Assistance program has enabled Saint Raphael to hire 30 neighborhood residents and help others find jobs elsewhere. Reaching beyond its immediate neighborhood, Saint Raphael also operates school-based health centers, clinics for elderly, a mobile clinic for pregnant women and new mothers, a parish nurse program in 21 area churches and congregations, and a home care network. In addition, Saint Raphael is working with the local United Way and other organizations to conduct a community needs assessment; working with Yale University and other organizations to increase neighborhood stability; and operating a program for the early detection of breast and cervical cancer in uninsured and underinsured women.

The effect of ethanol on sphincter of Oddi motility in vitro

Antioxidant enzymes are present in nerves supplying the sphincter of Oddi and regulate its motor function. Oxygen free radicals (O2.-) produce hydrogen peroxide (H2O2) by the action of superoxide dismutase (SOD). Hydroxyl radical (OH.), an important mediator of H2O2 toxicity, oxidizes ETOH. Thus, the aim of our study was determine the effects of ETOH on sphincter of Oddi motility. The sphincter of Oddi was removed from opossums and force transducers recorded tension in its transverse axis. Alcohol (ETOH) was added to the tissue bath in concentrations from 0.1 to 0.4%. OH. was generated by the addition of 0.01% H2O2. Nitric oxide production was inhibited by the addition of 0.3 mM N omega-nitro-L-arginine (L-NNA). H2O2 increased the frequency of sphincter of Oddi contractions. Concentrations of ETOH > 0.3% decreased contractile frequency; however, 0.2% ETOH alone had no affect on the basal frequency of contraction but inhibited the increase in contractile frequency caused by H2O2. L-NNA also increased the contractile frequency; however, this effect was not inhibited by ETOH. We conclude that ETOH attenuates the effect of H2O2 on sphincter of Oddi motility.

The effect of endotoxin on canine jejunal motility and transit

Intestinal transit is rapid during endotoxemia; however, little is known regarding the small intestinal motility changes which produce this rapid intestinal transit. The aim of our study was to determine the degree and duration of disrupted jejunal transit, and changes in jejunal motility following a sublethal dose of endotoxin. Eight dogs underwent construction of jejunal Thiry-Vella fistulas (TVF) with manometry catheters to record motility along the TVF. Following recovery, a 240-kcal liquid meal was given and the TVF was perfused with an isotonic solution. Liquid transit was assessed by bolus of a nonabsorbable marker instilled into the proximal end of the TVF. Recordings of gastrointestinal contractile activity were made digitally to determine postpandial motility. Following completion of the baseline studies, each dog was given a single dose of Escherichia coli lipopolysaccharide (200 micrograms/kg, iv) and the postprandial studies were repeated for the next 3 days. Endotoxin decreased the frequency of jejunal contractions for 2 days while the strength of jejunal contractions was diminished for 1 day. Jejunal transit of liquids was rapid on Postendotoxin Day 1. The rapid transit was associated with a greater percentage of single pressure waves propagating aborally on Postendotoxin Day 1 than the baseline percentages established prior to endotoxin. We conclude that endotoxemia temporarily disrupts postprandial jejunal motility and transit. The rapid liquid intestinal transit seen with endotoxemia may be due to changes in contractile propagation.

Impact of Vertical Banded Gastroplasty on Respiratory Insufficiency of Severe Obesity

BACKGROUND: Respiratory insufficiency associated with morbid obesity can include sleep apnea syndrome (SAS), obesity hypoventilation syndrome (OHS), or a combination of both. The aim of our study was to determine the safety and effectiveness of vertical banded gastroplasty (VBG) in the treatment of severely obese patients with respiratory insufficiency. METHODS: From 1983 to 1994, 35 patients (25 males, ten females) who met the criteria for either SAS and OHS (1 9 patients) or SAS alone (1 6 patients) underwent VBG. RESULTS: Six patients (17%) died of subsequent pulmonary-cardiac disease despite significant weight loss. Need for nasal continuous positive airway pressure (CPAP) decreased after VBG from 68% of patients preoperatively to 22% postoperatively. Of the ten patients with sleep studies, the apnea/hyponea index decreased from 45 +/- 11 events per h preoperatively to 12 +/- 6 events per h postoperatively, while per cent ideal body weight (%IBW) also decreased (pre-VBG: 268 +/- 12, post-VBG: 204 +/- 12). Of the seven patients with arterial blood gases, PaCO&inf2; decreased from 55 +/- 4 torr preoperatively to 41 +/- 3 torr postoperatively, and PaO&inf2; increased from 50 +/- 4 torr preoperatively to 73 +/- 6 torr postoperatively, while %IBW decreased (pre-VBG: 263 +/- 16, post-VBG: 193 +/- 14). CONCLUSION: Respiratory insufficiency is a life-threatening complication of morbid obesity. In morbidly obese patients with respiratory insufficiency, VBG offers improvement in both SAS and OHS. Respiratory insufficiency due to obesity should be considered a strong indication for VBG.

Gastrointestinal myoelectric activity during endotoxemia

BACKGROUND

Gastrointestinal myoelectric activity during postoperative ileus has been well characterized. However, the common clinical scenario of ileus occurring during and after episodes of sepsis is not well understood. The aim of our study was to determine the effects of a single, sublethal dose of endotoxin on canine gastrointestinal myoelectric activity.

METHODS

Eight dogs underwent placement of serosal electrodes on the stomach and small intestine and insertion of a jejunal cannula. After the animals recovered, electrical activity and jejunal mucosal blood flow were determined during fasting and with feeding. Following completion of these baseline studies dogs were given a single, sublethal dose of Escherichia coli lipopolysaccharide (200 g/kg) intravenously, and the studies were repeated daily for 3 consecutive days.

RESULTS

Endotoxin resulted in an absence of the interdigestive migrating myoelectric complex for 2 days, a decrease in duodenal and jejunal action potentials during fasting and with feeding, but no decreases in jejunal mucosal blood flow. The gastrointestinal myoelectrical patterns returned to those found in health on postendotoxin day 3.

CONCLUSIONS

A single, sublethal dose of endotoxin results in a temporary disruption of gastrointestinal myoelectric activity similar to that seen during postoperative ileus. The etiology of this "adynamic" ileus is unknown but does not appear to be secondary to intestinal ischemia.

Pay Status as a Predictor of Outcome in Surgical Treatment of Obesity

BACKGROUND: Higher complication rates and lower success in surgery for severe obesity have been reported for patients with government pay status. We examined the effect of pay status upon outcome in surgical treatment of obesity. METHODS: This was an observational study from an aggregate data set of individual patient information. Government pay status (G) was defined as full or partial medical care payment through Medicare, Medicaid, or Veterans Administration. Payment entirely by private insurance was defined as private (P). Operations were classified as either simple (S, gastric restriction) or complex (C, gastric restriction with small bowel bypass). Two measures of outcome, perioperative complication rate and weight loss success (</= 50% excess weight), were examined to determine pay status effect. RESULTS: More G than P patients were treated with simple procedures (79% vs 51%, p < 0.05). Perioperative complication rates were more common for G than P patients (14.4% vs 9.1%, p < 0.05). One-year weight loss success was higher for P than G, regardless of operation type. CONCLUSION: Pay status should be included in characterization of patient groups and in the analysis of results when effectiveness of surgical treatment for severe obesity is reported.

Functional characteristics of canine pylorus in health, with pyloroplasty, and after pyloric reconstruction

The aim was to determine whether pyloroplasty decreases the strength of pyloric contractions and speeds gastric emptying of solids, while subsequent pyloric reconstruction restores these abnormalities to the control. In conscious dogs, pyloroplasty decreased the strength of pyloroduodenal pressure waves measured with a perfused sleeve sensor [mean +/- SEM pyloroduodenal motility index: control (N = 7) = 1116 +/- 351 mm Hg x sec/10 min; pyloroplasty (N = 7) = 43 +/- 19 mm Hg x sec/10 min; P < 0.05], and caused rapid gastric emptying of solids measured scintigraphically (mean +/- SEM half-emptying time: control = 246 +/- 14 min, pyloroplasty = 176 +/- 16 min; P < 0.05). The frequencies of pyloroduodenal waves and gastric emptying of liquids, however, were unchanged. Pyloric reconstruction restored the postpyloroplasty patterns to the control. In conclusion, pyloroplasty decreased the strength of pyloroduodenal contractions and sped gastric emptying of solids, while pyloric reconstruction restored the altered patterns to the control.

Gastrointestinal transit during endotoxemia: the role of nitric oxide

We hypothesized that the disrupted gastrointestinal transit that occurs during endotoxemia is mediated by nitric oxide (NO) and that the inhibition of NO synthesis will normalize intestinal transit and gastric emptying. To determine the effects of endotoxin and steroids on the activity of gastrointestinal smooth muscle NO synthase, rats underwent placement of an intravenous (iv) line and then were given Escherichia coli lipopolysaccharide (LPS) 10 mg/kg/iv; LPS, 10 mg/kg/iv + dexamethasone, 3 mg/kg/iv; or saline. The activity of nitric oxide synthase in the stomach, small intestine, and colon were determined by measuring the conversion of L-[3H]arginine to L-[3H]citrulline. To determine intestinal transit and gastric emptying, gavage feedings of nonabsorbable liquid markers were given and rats divided into eight groups: 0.9% NaCl, 1 ml/hr x 5 hr (control); LPS, 10 mg/kg/iv; LPS + N-omega-nitro-L-arginine methyl ester (L-NAME), 10 mg/kg/hr x 5 hr; LPS + N-omega-nitro-D-arginine methyl ester (D-NAME), 10 mg/kg/hr x 5 hr; LPS + L-arginine, 100 mg/kg/hr x 5 hr; LPS + L+NAME + L-arginine; LPS + N-omega-nitro-L-arginine (L-NNA) 10 mg/kg/hr; or LPS + L-NNA + L-arginine. LPS increased the enzymatic activity of both the constitutive and the inducible forms of NO synthase in the small intestine and fundus of the stomach. The acceleration of intestinal transit produced by endotoxemia was reversed with both L-NAME and L-NNA but not with D-NAME. Endotoxemia slowed gastric emptying but this effect was not reversed with either L-NAME or L-NNA. We conclude that NO plays a major role in mediating the rapid intestinal transit during endotoxemia.

Effects of recombinant human hemoglobin on opossum sphincter of Oddi motor function in vivo and in vitro

Nitric oxide (NO) acts as a nonadrenergic, noncholinergic inhibitor neurotransmitter that regulates sphincter of Oddi (SO) motor function. Hemoglobin blocks NO activity by binding it after it is synthesized. We hypothesized that recombinant human hemoglobin (rHb1.1) affects SO motor function by scavenging NO. Under anesthesia, 12 opossums underwent biliary tract manometry. Following a stabilization period, six animals were given rHb1.1 (0.28 g/kg over 30 min), while six received bovine albumin (0.28 g/kg over 30 min). Recordings were made during the infusion and for 3 hr after the infusion. In an in vitro preparation, force transducers were used to record spontaneous contractions at two sites along the sphincter segment. After a control period, rHb1.1 (0.1 mM) or cyanomethemoglobin (0.1 mM) was added to the tissue bath and recordings continued for another 2 hr. Recombinant human hemoglobin decreased the frequency of contractions, increased resting tone, and blocked the relaxation phase of contraction in vivo. It increased the baseline amplitude, the frequency, and the peak amplitudes of contractions in vitro. Albumin or cyanomethoglobin, which are unable to bind NO, had little effect on SO motor activity. We conclude that rHb1.1 may alter SO motor function by binding endogenous NO.

The management of extrahepatic portal vein aneurysms: observe or treat?

A case of a 70 year old man who was found to have an extrahepatic portal vein aneurysm during an evaluation for hematuria is reported. Extrahepatic portal vein aneurysms are rare with only twenty cases reported in the literature. Typically, patients present with hemorrhage requiring surgical exploration or the aneurysm is discovered during evaluation of another abdominal process. Management includes careful follow-up in the asymptomatic patient without underlying liver disease or portal hypertension.

Reversal of small intestinal bypass operations and concomitant vertical banded gastroplasty: long-term outcome

BACKGROUND

Long-term complications of jejunoileal bypass (JIB) have been reported, prompting restoration of intestinal continuity and concomitant performance of vertical banded gastroplasty (VBG) for weight control. The aim of this study was to evaluate the presentation and reversal of JIB complications, late complications, mortality, and long-term weight control in patients who have undergone JIB reversal and concomitant VBG.

STUDY DESIGN

From 1981 to 1994, 37 patients were treated for complications from JIB that included diarrhea (73 percent), arthritis (46 percent), malnutrition (22 percent), urolithiasis (19 percent), electrolyte disorders (19 percent), and lack of weight loss (8 percent). Four patients required preoperative parenteral nutrition to correct protein and electrolyte imbalances. Surgical management of all 37 patients included restoration of bowel continuity and VBG during the same operative procedure.

RESULTS

Postoperative complications occurred in 11 patients, including prolonged ileus in seven patients, pancreatitis in three patients, and infectious complications in two. There were no deaths. Late morbidity included staple line dehiscence in four patients, incisional hernia in three patients, and reversal of the VBG in one. All patients with diarrhea, malnutrition, electrolyte disorders, and lack of weight loss had resolution of their symptoms, while urolithiasis and arthritis resolved in 86 and 53 percent of patients, respectively. In patients available for five-year follow-up evaluation, weight changes were small, shifting from a preoperative weight of 87 +/- 19 to 90 +/- 19 kg at five years (mean +/- SD).

CONCLUSIONS

Restoration of intestinal continuity combined with VBG is a safe and effective operation that will reverse most of the long-term complications of JIB and provide stable weight control for up to five years.

The Effect of Follow-up on Reporting Success for Obesity Surgery

BACKGROUND: Much is written about the importance of follow-up in determining the effect of surgical treatment for obesity upon weight loss. When patients are lost to follow-up, it has been suggested that these patients should be considered as failures. This study was undertaken to determine the effect of incorporating patients not followed in a definition of success for weight loss at one year. METHODS: Data from 34 surgical practices were used to study the effect of using two different denominators, patients followed (Df) or patients eligible (De), to define success. The numerator used in both methods was the number of patients with </= 50% EW at 1 year. RESULTS: One-year follow-up was 61% (5091/8356). Success was 67% (3423/5091) when calculated using the denominator patients followed (Df). No correlation was found between success and follow-up when data within each surgical practice were averaged and used in a correlation analysis. CONCLUSIONS: This study does not support the thesis that patients who fall to return for follow-up should be considered as having failed in weight control.

Ectopic jejunal pacemakers after jejunal transection and their relationship to transit

The hypothesis was that orally moving pacesetter potentials distal to a site of jejunal transection and anastomosis would slow transit through jejunum containing them and that reoperation with excision of bowel containing these pacesetter potentials would restore transit to the control. In six conscious dogs with jejunal serosal electrodes for recording myoelectric activity and a jejunal perfusion/aspiration catheter for measuring transit, jejunal pacesetter potential frequency decreased distal to a midjejunal transection and anastomosis from 18.7 +/- 0.3 (SE) cycles/min (cpm) proximal to the site to 14.4 +/- 0.6 cpm distal to the site (P < 0.05). In addition, orally propagating pacesetter potentials occurred > 25% of the time in a 37 +/- 7 cm length of bowel distal to the site during fasting and after feeding. Transit through the segment with the orally moving pacesetter potentials was slowed during feeding (half time before and after transection, 7.7 +/- 1.1 and 13 +/- 2.0 min, respectively, P < 0.05). Resection of the segment with the abnormal pacesetter potentials shortened the length of bowel containing them to 24 +/- 2 cm (P > 0.05) and restored transit to the control. In conclusion, orally moving pacesetter potentials distal to a canine jejunal transection and anastomosis slowed transit through the segment of bowel containing them. Resection of the segment restored transit to the control.

Vertical Banded Gastroplasty in the Severely Obese under Age Twenty-One

BACKGROUND: The severely obese under 21 years of age are at high risk of missing normal development during a crucial period of life and should be considered for surgical treatment. Vertical banded gastroplasty allows patients to be treated effectively while continuing to have normal digestion and absorption without the risks of complex operations. METHODS: This was a retrospective outcome review of 47 severely obese who were under age 21 when surgically treated with VBG. RESULTS: There were no operative mortalities, leaks, or wound infections. Body mass index in 25 patients followed 5 years decreased from an average operative 48.1 to 36.2 kg m(2). Equally for 14 patients followed 10 years, BMI decreased from an average operative 49.6 to 39.2 kg m (2). Both patient groups had 74% follow-up. CONCLUSIONS: Sustained weight reduction improved general health and allowed participation in life activities that would otherwise not have been possible. Adherence to recommended operative technique and intraoperative measurement of pouch volume is necessary to avoid excessive enlargement of the pouch, with resulting weight gain, reflux, and need for revision.

Tonic responses of canine proximal colon: effects of eating, nutrients, and simulated diarrhea

Our hypothesis was that the proximal colon relaxes to accommodate flow from the ileum. Therefore, we recorded tonic responses of the canine proximal colon to flow through the ileum and colon stimulated by 1) an 840-kcal meal, 2) nutrients perfused into the ileum and colon, or 3) rapid infusion of saline into the ileum with overflow into the colon. Saline infusion was considered to be a model of diarrhea, and the effects of an antidiarrheal (morphine sulfate) were therefore assessed. Proximal colonic tone was measured with a barostat. Tone increased before and after the arrival of chyme in the ileocolonic region. Perfusion of nutrients into the ileum and colon also significantly increased (P < 0.05) colonic tone compared with equal volumes of saline. Rapid perfusion of the ileocolonic segment with saline increased colonic tone; this increase was significantly greater (P < 0.01) when preceded by morphine. In contrast to our hypothesis, tone of the canine proximal colon increased in response to ileal flow. The increase in colonic tone during the late response to food was at least partly attributable to stimulation by intraluminal contents.

Epidural analgesia shortens postoperative ileus after ileal pouch-anal canal anastomosis

PURPOSE

A retrospective study was conducted to determine whether epidural analgesia would speed recovery from postoperative ileus in patients undergoing ileal pouch-anal canal anastomosis.

METHODS

Among 85 patients who underwent proctocolectomy with ileal pouch-anal canal anastomosis at the Mayo Medical Center between January 1, 1991 and October 31, 1992, 44 were treated for postoperative pain with continuous infusion of epidural fentanyl citrate supplemented by intravenous morphine on request, while 41 controls were given only systemic morphine sulfate as needed.

RESULTS

The patients in the two groups were matched and similar with regard to preoperative and operative risk factors and postoperative morbidity. No operative mortality occurred. Epidural fentanyl analgesia resulted in less need for nasogastric suction and intravenous fluids, more rapid discharge of fecal content, more rapid return to oral intake, and shorter hospitalization.

CONCLUSION

Epidural analgesia with fentanyl citrate shortened postoperative ileus after proctocolectomy and ileal pouch-anal canal anastomosis.

Effect of endotoxin on canine gastrointestinal motility and transit

Ileus is common during sepsis; however, the etiology of this gastrointestinal dysmotility is unclear. The aim of our study was to determine the effects of a single, sublethal dose of endotoxin on canine gastrointestinal motility, gastric emptying, gastric acid secretion, and colonic transit. Six dogs underwent placement of manometric catheters in the stomach and small bowel and insertion of a gastric and a cecal cannula. After the animals recovered, fasting and fed gastrointestinal motility was recorded, and gastric emptying and colonic transit were studied with nonabsorbable liquid and solid markers, respectively. Following completion of baseline studies, each dog was given a single dose of Escherichia coli lipopolysaccharide (200 micrograms/kg intravenously) and the studies were repeated on Postendotoxin Days 1-3. The single bolus of endotoxin abolished the migrating motor complexes, decreased the fasting motility index, decreased hydrogen ion output, slowed liquid gastric emptying, and prolonged colonic transit for 2 days. Gastrointestinal motility and transit returned to baseline on Postendotoxin Day 3. In conclusion, a single, sublethal dose of endotoxin temporarily disrupts fasting and postprandial canine gastrointestinal motility and transit.