Chronic dehydration and sodium depletion in patients with established ileostomies

Protein-based oral rehydration solutions for patients with an ileostomy: A randomised, double-blinded crossover study

BACKGROUND & AIM

Patients with an ileostomy are at increased risk of dehydration and sodium depletion. Treatments recommended may include oral rehydration solutions (ORS). We aimed to investigate if protein type or protein hydrolysation affects absorption from iso-osmolar ORS in patients with an ileostomy.

METHODS

This was a randomised, double-blinded, active comparator-controlled 3 × 3 crossover intervention study. We developed three protein-based ORS with whey protein isolate, caseinate or whey protein hydrolysate. The solutions contained 40-48 g protein/L, 34-45 mmol sodium/L and had an osmolality of 248-270 mOsm/kg. The patients ingested 500 mL/d. The study consisted of three 4-week periods with a >2-week washout between each intervention. The primary outcome was wet-weight ileostomy output. Ileostomy output and urine were collected for a 24-h period before and after each intervention. Additionally, blood sampling, dietary records, muscle-strength tests, bioimpedance analyses, questionnaires and psychometric tests were conducted.

RESULTS

We included 14 patients, of whom 13 completed at least one intervention. Ten patients completed all three interventions. Wet-weight ileostomy output did not change following either of the three interventions and did not differ between interventions (p = 0.38). A cluster of statistically significant improvements related to absorption was observed following the intake of whey protein isolate ORS, including decreased faecal losses of energy (-365 kJ/d, 95% confidence interval (CI), -643 to -87, p = 0.012), potassium (-7.8 mmol/L, 95%CI, -12.0 to -3.6, p = 0.001), magnesium (-4.0 mmol/L, 95%CI, -7.4 to -0.7, p = 0.020), improved plasma aldosterone (-4674 pmol/L 95%CI, -8536 to -812, p = 0.019), estimated glomerular filtration rate (eGFR) (2.8 mL/min/1.73 m2, 95%CI, 0.3 to 5.4, p = 0.03) and CO2 (1.7 mmol/L 95%CI, 0.1 to 3.3, p = 0.04).

CONCLUSION

Ingestion of 500 mL/d of iso-osmolar solutions containing either whey protein isolate, caseinate or whey protein hydrolysate for four weeks resulted in unchanged and comparable ileostomy outputs in patients with an ileostomy. Following whey protein isolate ORS, we observed discrete improvements in a series of absorption proxies in both faeces and blood, indicating increased absorption. The protein-based ORS were safe and well-tolerated. Treatments should be tailored to each patient, and future studies are warranted to explore treatment-effect heterogeneity and whether different compositions or doses of ORS can improve absorption and nutritional status in patients with an ileostomy.

CLINICALTRIALS

GOV STUDY IDENTIFIER

NCT04141826.

Sodium depletion and secondary hyperaldosteronism in outpatients with an ileostomy: a cross-sectional study

OBJECTIVE

Patients with an ileostomy may experience postoperative electrolyte derangement and dehydration but are presumed to stabilise thereafter. We aimed to investigate the prevalence of sodium depletion in stable outpatients with an ileostomy and applied established methods to estimate their fluid status.

METHODS

We invited 178 patients with an ileostomy through a region-wide Quality-of-Life-survey to undergo outpatient evaluation of their sodium and fluid status. The patients delivered urine and blood samples, had bioelectrical impedance analysis performed and answered a questionnaire regarding dietary habits.

RESULTS

Out of 178 invitees, 49 patients with an ileostomy were included; 22 patients (45%, 95% CI, 31-59%) had unmeasurably low urinary sodium excretion (<20 mmol/L), indicative of chronic sodium depletion, and 26% (95% CI, 16-41%) had plasma aldosterone levels above the reference value. Patients with unmeasurably low urinary sodium excretion had low estimated glomerular filtration rates (median 76, IQR 63-89, mL/min/1.73m2) and low venous blood plasma CO2 (median 24, IQR 21-26, mmol/L), indicative of chronic renal impairment and metabolic acidosis. Bioelectrical impedance analysis, plasma osmolality, creatinine and sodium values were not informative in determining sodium status in this population.

CONCLUSION

A high proportion of patients with an ileostomy may be chronically sodium depleted, indicated by absent urinary sodium excretion, secondary hyperaldosteronism and chronic renal impairment, despite normal standard biochemical tests. Sodium depletion may adversely affect longstanding renal function. Future studies should investigate methods to estimate and monitor fluid status and aim to develop treatments to improve sodium depletion and dehydration in patients with an ileostomy.IMPACT AND PRACTICE RELEVANCE STATEMENTSodium depletion in otherwise healthy persons with an ileostomy was identified in a few publications from the 1980s. The magnitude of the problem has not been demonstrated before. The present study quantifies the degree of sodium depletion and secondary hyperaldosteronism in this group, and the results may help guide clinicians to optimise treatment. Sodium depletion is easily assessed with a urine sample, and sequelae may possibly be avoided if sodium depletion is detected early and treated. This could ultimately help increase the quality of life in patients with an ileostomy.

New Ileostomy Formation and Subsequent Community-onset Acute and Chronic Kidney Disease: A Population-based Cohort Study

OBJECTIVE

The aim of this study was to examine relationships between ileostomy formation and subsequent kidney disease.

SUMMARY AND BACKGROUND DATA

Colonic absorptive capacity loss from ileostomy formation can cause volume depletion and could result in kidney disease.

METHODS

We conducted a population-based cohort study comparing patients who underwent ileostomy formation with or without bowel resection (ileostomy group) to patients who underwent bowel resection without ileostomy formation (reference group). Adjusted odds ratios (aORs) for community-onset acute kidney injury (AKI) within 3 months and new-onset chronic kidney disease (CKD) within 1 year following hospital discharge were determined.

RESULTS

Among 19,889 patients, 4136 comprised the ileostomy group and 15,753 comprised the reference group; 1350 patients experienced community-onset AKI and 464 developed new-onset CKD. The aOR for community-onset AKI with ileostomy formation was 4.08 [95% confidence interval (CI) = 3.62-4.61] for any stage AKI, 7.08 (95% CI = 5.66-8.85) for stage ≥2 injury, and 7.67 (95% CI = 5.06-11.63) for stage 3 injuries. Community-onset AKI modified associations between ileostomy formation and new-onset CKD (P = 0.002). Odds of new-onset CKD were increased in the ileostomy group relative to the reference group for patients both with (aOR = 4.99; 95% CI = 3.42-7.28) and without (aOR = 2.45; 95% CI = 1.85-2.23) previous community-onset AKI episodes. In analyses comparing patients that underwent ileostomy formation and subsequent reversal within 1 year to the reference group without ileostomy, the relationship with new-onset CKD was attenuated for patients both with (aOR = 2.49; 95% CI = 1.50-4.12) and without (aOR = 0.97; 95% CI = 0.67-1.40) previous community-onset AKI episodes.

CONCLUSIONS

Ileostomy formation is strongly associated with subsequent kidney disease. Vigilance for this complication and new strategies for prevention and treatment are necessary.

Renal impairment after ileostomy formation: a frequent event with long-term consequences

AIM

High stoma output and dehydration is common following ileostomy formation. However, the impact of this on renal function, both in the short term and after ileostomy reversal, remains poorly defined. We aimed to assess the independent impact on kidney function of an ileostomy after rectal cancer surgery and subsequent reversibility after ileostomy closure.

METHODS

This retrospective single-site cohort study identified patients undergoing rectal cancer resection from 2003 to 2017, with or without a diverting ileostomy. Renal function was calculated preoperatively, before ileostomy closure, and 6 months after ileostomy reversal (or matched times for patients without ileostomy). Demographics, oncological treatments and nephrotoxic drug prescriptions were assessed. Outcome measures were deterioration from baseline renal function and development of moderate/severe chronic kidney disease (CKD ≥ 3). Multivariate analysis was performed to assess independent risk factors for postoperative renal impairment.

RESULTS

Five hundred and eighty-three of 1213 patients had an ileostomy. Postoperative renal impairment occurred more frequently in ileostomates (9.5% absolute increase in rate of CKD ≥ 3; P < 0.0001) vs no change in patients without an ileostomy (P = 0.757). Multivariate analysis identified ileostomy formation, age, anastomotic leak and renin-angiotensin system inhibitors as independently associated with postoperative renal decline. Despite stoma closure, ileostomates remained at increased risk of progression to new or worse CKD [74/438 (16.9%)] compared to patients without an ileostomy [36/437 (8.2%), P = 0.0001, OR 2.264 (1.49-3.46)].

CONCLUSIONS

Ileostomy formation is independently associated with kidney injury, with an increased risk persisting after stoma closure. Strategies to protect against kidney injury may be important in higher risk patients (elderly, receiving renin-angiotensin system antihypertensives, or following anastomotic leakage).

A novel patient-centered protocol to reduce hospital readmissions for dehydration after ileostomy

Early hospital readmission for dehydration represents a relevant problem among patients with diverting or terminal ileostomy. The aim of the study was to evaluate the efficacy of a new multidisciplinary individualized multistep protocol in terms of reduction of hospital readmission for dehydration. Since January 2016, our institution adopted a new protocol for patients with ileostomy. Protocol key points were: preoperative personalized education in stoma management; early recognition of dehydration symptoms; multidisciplinary counseling; patient autonomy in stoma management through post-operative recall schedule. The study compared a series of consecutive patients treated before (2014-2015) and after (2016-2017) the protocol application. The primary endpoint was hospital readmission rate after protocol use. The secondary endpoint was the identification of possible risk factors for readmission. The entire cohort was composed of 296 patients, 129 in the protocol group and 167 in the control one. The two groups were homogeneous for baseline characteristics. Hospital readmission rate within 30 days post-discharge for dehydration dropped from 9 to 3.9% after protocol application. Specifically, the number of avoided potential readmissions was 29/129 (22.4%). The number needed to treat (NNT) was 20. Univariate analysis identified three relevant variables: patient comorbidities, diuretics use as risk factors and protocol application as the protective one. The multivariate analysis confirmed patient comorbidity as the risk factor. Dehydration related to ileostomy is a potentially avoidable problem, by employing preventive strategies, especially in high-risk patients. Our new protocol could be a simple and cost-saving method, effective in preventing hospital readmissions.

An iso-osmolar oral supplement increases natriuresis and does not increase stomal output in patients with an ileostomy: A randomised, double-blinded, active comparator, crossover intervention study

BACKGROUND

Patients with an ileostomy often experience fluid and electrolyte depletion because of gastrointestinal loss. This study aimed to compare how an iso-osmolar and a hyperosmolar oral supplement affect ileostomy output, urine production, and natriuresis as proxy measurements of water-electrolyte balance.

METHODS

In a randomised, double-blinded, active comparator, crossover intervention study, we included eight adult ileostomy patients who were independent of parenteral support. We investigated how an iso-osmolar (279 mOsm/kg) and a hyperosmolar (681 mOsm/kg) oral supplement affected ileostomy output mass, urine volume, and natriuresis. In addition to their habitual diet, each participant ingested 800 mL/day of either the iso-osmolar or hyperosmolar supplement in each of two study periods. Each period started with 24-hour baseline measurements, and the supplements were ingested during the following 48 h. All measurements were repeated in the last 24 h.

RESULTS

No statistically significant changes in ileostomy output were detected following the intake of either oral supplement (median (range) 67 (-728 to 290) g/day, p = 0.25) despite increased fluid intake. Compared with the hyperosmolar supplement, the iso-osmolar supplement induced a statistically significant increase in urine volume (470 (0-780) mL/day, p = 0.02) and natriuresis (36 (0-66) mmol/day, p = 0.02).

CONCLUSION

Intake of the two oral supplements did not affect ileostomy output during this short intervention. Natriuresis increased following intake of the iso-osmolar supplement compared to that after ingesting the hyperosmolar supplement, indicating that patients with an ileostomy may benefit from increasing their ingestion of iso-osmolar fluids. ClinicalTrials.gov identifier:NCT03348709.

Bacteria, Bones, and Stones: Managing Complications of Short Bowel Syndrome

Short bowel syndrome (SBS) occurs in patients who have had extensive resection. The primary physiologic consequence is malabsorption, resulting in fluid and electrolyte abnormalities and malnutrition. Nutrient digestion, absorption, and assimilation may also be diminished by disturbances in the production of bile acids and digestive enzymes. Small bowel dilation, dysmotility, loss of ileocecal valve, and anatomical changes combined with acid suppression and antimotility drugs increase the risk of small intestinal bacterial overgrowth, further contributing to malabsorption. Metabolic changes that occur in SBS due to loss of colonic regulation of gastric and small bowel function can also lead to depletion of calcium, magnesium, and vitamin D, resulting in demineralization of bone and the eventual development of bone disease. Persistent inflammation, steroid use, parenteral nutrition, chronic metabolic acidosis, and renal insufficiency may exacerbate the problem and contribute to the development of osteoporosis. Multiple factors increase the risk of nephrolithiasis in SBS. In the setting of fat malabsorption, increased free fatty acids are available to bind to calcium, resulting in an increased concentration of unbound oxalate, which is readily absorbed across the colonic mucosa where it travels to the kidney. In addition, there is an increase in colonic permeability to oxalate stemming from the effects of unabsorbed bile salts. The risk of nephrolithiasis is compounded by volume depletion, metabolic acidosis, and hypomagnesemia, resulting in a decrease in renal perfusion, urine output, pH, and citrate excretion. This review examines the causes and treatments of small intestinal bacterial overgrowth, bone demineralization, and nephrolithiasis in SBS.

Total body sodium depletion and poor weight gain in children and young adults with an ileostomy: a case series

Patients with high-output small bowel ostomies are at risk for total body sodium depletion (TBSD), defined as a urine sodium level <10 mmol/L. Failure to thrive (FTT) as a consequence of TBSD has been reported in neonates with ileostomies; however, this has not been well described in older children. The records of all children beyond the age of infancy with a small bowel ostomy cared for in our Children's Intestinal Rehabilitation Program from 2010-2012 were reviewed. Four patients between the ages of 18 months and 19 years were identified as having TBSD. All 4 patients experienced unintentional weight loss, despite adequate energy intake based on calculated needs, which was associated with a urine sodium level ≤10 mmol/L. With the supplementation of sodium, either enteral or intravenous, all patients demonstrated improved weight gain and correction of TBSD. The following cases suggest that the relationship between TBSD and FTT may extend well beyond the neonatal period and possibly into adulthood. We advise that patients of all ages with high stoma output have routine urine sodium levels checked, particularly in the setting of weight loss or poor gain. Furthermore, instances of TBSD should be treated with sodium supplementation. Further research is needed to better understand the relationship between TBSD and FTT and to establish intervention guidelines.

Readmission for dehydration or renal failure after ileostomy creation

BACKGROUND

Ileostomy creation is a commonly performed operation in colorectal surgery; however, many patients develop complications such as dehydration postoperatively. Dehydration is often severe enough to warrant hospital readmission and may result in renal failure. The true incidence of this complication has not been well described.

OBJECTIVE

The aim of this study was to identify the rate of hospital readmission secondary to dehydration or renal failure within 30 days of ileostomy creation.

DESIGN

Retrospective review of all patients undergoing ileostomy creation from 2007 to 2011 in a single colorectal practice of 4 surgeons was performed. Charts were reviewed to identify patients readmitted for dehydration or renal failure within 30 days of operation. Data were then analyzed to identify predictors of readmission, dehydration, and renal failure. Subset analysis compared patients readmitted with simple dehydration versus patients with renal failure.

PATIENTS

Two hundred one patients undergoing colorectal operations that included ileostomy creation within a 4-year period at a single institution for a variety of indications were included.

MAIN OUTCOME MEASURES

The primary outcome measured was readmission for dehydration or renal failure.

RESULTS

We observed a 17% 30-day readmission rate for dehydration or renal failure following ileostomy creation. Age greater than 50 was identified as an independent predictor of readmission with renal failure, whereas IPAA was predictive of readmission for simple dehydration, but not renal failure. Patients admitted with renal failure had significantly longer hospital stays and median hospital charges after readmission in comparison with patients admitted with simple dehydration.

LIMITATIONS

This study was limited by its retrospective nature and its limited sample size.

CONCLUSION

Hospital readmission due to dehydration or renal failure following ileostomy creation is common, with age >50 being the strongest predictor for renal failure. Appropriate strategies to decrease dehydration and renal failure following ileostomy creation need to be investigated.

Intra-tubular deposits, urine and stone composition are divergent in patients with ileostomy

Patients with ileostomy typically have recurrent renal stones and produce scanty, acidic, sodium-poor urine because of abnormally large enteric losses of water and sodium bicarbonate. Here we used a combination of intra-operative digital photography and biopsy of the renal papilla and cortex to measure changes associated with stone formation in seven patients with ileostomy. Papillary deformity was present in four patients and was associated with decreased estimated glomerular filtration rates. All patients had interstitial apatite plaque, as predicted from their generally acid, low-volume urine. Two patients had stones attached to plaque; however, all patients had crystal deposits that plugged the ducts of Bellini and inner medullary collecting ducts (IMCDs). Despite acid urine, all crystal deposits contained apatite, and five patients had deposits of sodium and ammonium acid urates. Stones were either uric acid or calcium oxalate as predicted by supersaturation, however, there was a general lack of supersaturation for calcium phosphate as brushite, sodium, or ammonium acid urate because of the overall low urine pH. This suggests that local tubular pH exceeds that of bulk urine. Despite low urine pH, patients with an ileostomy resemble those with obesity bypass, in whom IMCD apatite crystal plugs are found. They are, however, unlike these bypass patients in having interstitial apatite plaque. IMCD plugging with sodium and ammonium acid urate has not been found previously and appears to correlate with formation of uric acid stones.

Aldosterone enhances 11beta-hydroxysteroid dehydrogenase type 2 expression in colonic epithelial cells in vivo

OBJECTIVE

[corrected] 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) metabolizes glucocorticoids, thus enabling aldosterone to bind to the mineralocorticoid receptor. However, little is known about the regulatory mechanism of epithelial 11beta-HSD2 expression in the gut.

MATERIALS AND METHODS

Sprague-Dawley rats were maintained on a sodium-depleted diet or subjected to continuous aldosterone infusion for 4 weeks. Plasma aldosterone and arginine-vasopressin (AVP) levels were measured by radioimmunoassay. Expression of 11beta-HSD2 in colonic epithelia was evaluated by Northern blotting and immunohistochemistry. T84 and Caco2 cells were stimulated with aldosterone, dexamethasone and AVP alone or in combination, and 11beta-HSD2 mRNA was measured by quantitative reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Sodium-depleted and aldosterone-infused rats showed an increase of plasma aldosterone and AVP. Both treatments resulted in induction of 11beta-HSD2 in the colonic epithelia at mRNA and protein levels. Positive immunoreactivity was detected in the cytoplasm of the surface epithelia in control rats. In contrast, epithelial cells in the crypt also showed immunoreactivity for 11beta-HSD2 in the proximal colon of dietary sodium-depleted and aldosterone-infused rats. Induction of 11beta-HSD2 mRNA was observed when T84 cells were stimulated with corticosteroids plus AVP.

CONCLUSIONS

Aldosterone has a pivotal role by increasing expression of 11beta-HSD2 in epithelial cells of the colon. AVP may act as a synergistic hormone in aldosterone-mediated 11beta-HSD2 induction.

Comparative study of epithelial gene expression in the small intestine among total proctocolectomized, dietary sodium-depleted, and aldosterone-infused rats

We previously demonstrated enhanced plasma aldosterone, ileal activation of epithelial sodium channel (ENaC), and induction of 11 beta-hydroxysteroid dehydrogenase type 2 after total proctocolectomies in rats. However, factors other than circulating aldosterone may cause molecular induction associated with sodium transport. Sprague-Dawley rats were treated with sodium-deficient diets or subcutaneous aldosterone infusion for 4 weeks. Rats also underwent total proctocolectomies as positive control. We extracted epithelial RNA from the distal small intestine and compared mRNA expression of the alpha, beta, and gamma subunits of ENaC, prostasin, sodium glucose transporter 1 (SGLT1), and the alpha1 and beta1 subunits of Na(+)/K(+)-ATPase among control, total proctocolectomized, dietary sodium-depleted, and aldosterone-infused rats by quantitative reverse transcription-polymerase chain reaction or Northern blotting. A significant increase in aldosterone was noted in sodium-depleted and aldosterone-infused rats. The induction of three subunits of ENaC and prostasin mRNA was observed in proctocolectomized, aldosterone-infused rats but not in dietary sodium-depleted rats. The levels of the alpha1 and beta1 subunits of Na(+)/K(+)-ATPase were similar among the experimental groups. SGLT1 mRNA was induced only in proctocolectomized rats. The molecular induction of ENaC, prostasin, and SGLT1 is unique for total proctocolectomized rats. Aldosterone infusion can induce several essential molecules for sodium absorption, as seen in total proctocolectomy.

Induction of 11beta-hydroxysteroid dehydrogenase type 2 and hyperaldosteronism are essential for enhanced sodium absorption after total colectomy in rats

BACKGROUND

Patients who undergo total colectomy with ileopouch anal reconstruction often have persistent diarrhea and frequent bowel movements. Analysis of the intestinal adaptation after total colectomy may lead to developing novel therapies for postoperative diarrhea.

METHODS

Sprague-Dawley rats underwent total colectomy with ileoanal reconstruction and were sacrificed 4 and 8 weeks later. Mucosal response to aldosterone was evaluated with the use of ileal mucosa in an Ussing chamber by measuring short circuit current after in vitro stimulation with aldosterone. We investigated the expression of 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD 2) in intestinal epithelial cells. To examine the role of hyperaldosteronism, we also evaluated rats treated with a sodium-deficient diet or subcutaneous aldosterone infusion.

RESULTS

Aldosterone levels increased 80-fold after total colectomy. A comparable amount of aldosterone dramatically increased aldosterone-mediated, amiloride-sensitive short circuit current in the mucosa from colectomized rats, but not in control rats. We measured an increase in 11beta-HSD 2 messenger RNA and protein in the distal ileum from colectomized rats. Circulating aldosterone appears to be essential for these functional and molecular changes because similar results were obtained by using the mucosa from both dietary sodium-depleted and aldosterone-infused rats.

CONCLUSIONS

Induction of 11beta-HSD 2 is essential for enhanced mineralocorticoid action in the remnant ileum after total colectomy in rats.

Pseudo-hypoaldostéronismes

TWO FORMS: Pseudohypoaldosteronisms (PHA) are characterized by end-organ resistance to aldosterone inducing hyperkalemia and hyperaldosteronism. There are two forms of PHA classified according to the level of blood pressure with either hypotension (Type 1 PHA or PHA 1) or hypertension (Type 2 PHA or PHA 2). PHA 1: The association with hypotension and high renin level (PHA 1) is responsible for type 4 tubular acidosis and should suggest congenital or acquired excessive salt loss. Acquired forms are associated with salt wasting of urinary (nephropathy) or digestive (colon resection + ileostomy) origin. Congenital neonatal forms are either sporadic or autosomal dominant or recessive. Sporadic or autosomal dominant forms are caused by mutations in the mineralocorticoid receptor gene and generally remit with age. Autosomal recessive forms are caused by mutations in the gene encoding the amiloride-sensitive sodium channel and are clinically more severe with pulmonary symptoms. PHA 2: The association of hyperkalemia/hyperaldosteronism with high blood pressure should suggest PHA 2 or Gordon's syndrome, still called familial hyperkalemic hypertension. This form of low-renin hypertension is caused by mutations in the WNK genes (WNK 1 for PHA 2C and WNK 4 for PHA 2B), but other genes located on different loci are also involved. These WNK kinases constitute a new signalisation pathway that would regulate blood pressure and homeostasy of Na+, K+, H+ and Cl- ions.

Hepatobiliary, renal and bone complications of intestinal failure

Abnormal liver function tests in patients with intestinal failure (IF) may be due to the underlying disease, IF or the treatments given (including parenteral nutrition (PN)). PN-related liver disease in children usually relates to intrahepatic cholestasis and in adults to steatosis. Steatosis may be consequent upon an excess of carbohydrate, lipid or protein, or upon a deficiency of a specific molecule. Pigment-type gallstones are common in adults and children with IF; these develop from biliary sludge that forms during periods of gallbladder stasis. Ileal disease/resection, parenteral nutrition, surgery, rapid weight loss and drugs all increase the risk of developing gallstones. Gallstone formation may be prevented by reducing gallbladder stasis (oral/enteral feeding or prokinetic agents), altering bile composition, or by means of a prophylactic cholecystectomy. Calcium oxalate renal stones are common in patients with a short bowel and retained functioning colon and are consequent upon increased absorption of dietary oxalate; they are prevented by a low-oxalate diet. An osteopathy may occur with long-term parenteral nutrition.

Transient pseudo-hypoaldosteronism following resection of the ileum: normal level of lymphocytic aldosterone receptors outside the acute phase

Pseudo-hypoaldosteronism (PHA) is due to mineralocorticoid resistance and manifests as hyponatremia and hyperkalemia with increased plasma aldosterone levels. It may be familial or secondary to abnormal renal sodium handling. We report the case of a 54-year-old woman with multifocal cancer of the colon, who developed PHA after subtotal colectomy, ileal resection and jejunostomy. She was treated with 6 g of salt daily to prevent dehydration, which she stopped herself because of reduced fecal losses. One month later she was admitted with signs of acute adrenal failure, i.e. fatigue, severe nausea, blood pressure of 80/60 mmHg, extracellular dehydration, hyponatremia (118 mmol/l); hyperkalemia (7.6 mmol/l), increased blood urea nitrogen (BUN) (200 mg/dl) and creatininemia (2.5 mg/dl), and decreased plasma bicarbonates level (HCO3-: 16 mmol/l; N: 27-30). However, the plasma cortisol was high (66 microg/100 ml at 10:00 h; N: 8-15) and the ACTH was normal (13 pg/ml, N: 10-60); there was a marked increase in plasma renin activity (>37 ng/ml/h; N supine <3), active renin (869 pg/ml; N supine: 1.120), aldosterone (>2000 pg/ml; N supine <150) and plasma AVP (20 pmol/l; N: 0.5-2.5). The plasma ANH level was 38 pmol/l (N supine: 5-25). A urinary steroidogram resulted in highly elevated tetrahydrocortisol (THF: 13.3 mg/24h; N: 1.4+/-0.8) with no increase in tetrahydrocortisone (THE: 3.16 mg/24h; N: 2.7+/-2.0) excretion, and with low THE/THF (0.24; N: 1.87+/-0.36) and alpha THF/THF (0.35; N: 0.92+/-0.42) ratios. The number of mineralocorticoid receptors in mononuclear leukocytes was in the lower normal range for age, while the number of glucocorticoid receptors was reduced. Small-bowel resection in ileostomized patients causes excessive fecal sodium losses and results in chronic sodium depletion with contraction of the plasma volume and severe secondary hyperaldosteronism. Nevertheless, this hyperaldosteronism may be associated with hyponatremia and hyperkalemia suggesting PHA related to the major importance of the colon for the absorption of sodium. In conclusion, this case report emphasizes 1) the possibility of a syndrome of acquired PHA with severe hyperkalemia after resection of the ileum and colon responding to oral salt supplementation; 2) the major increase in AVP and the small increase in ANH; 3) the strong increase in urinary THF with low THE/THF and alpha THF/THF ratios; 4) the normal number of lymphocytic mineralocorticoid receptors outside the acute episode.

Metabolic consequences of total colectomy

Colectomy is performed for inflammatory bowel disease, familial polyposis syndrome and colorectal carcinoma. Surgical procedures are ileostomy with or without pouch, ileorectal anastomosis or ileal pouch-anal anastomosis. One of the major functions of the intact large intestine is to absorb water and electrolytes. After colectomy, as much as 400-1000 ml of nearly isotonic ileostomy fluid may be excreted, resulting in a chronic salt and water depletion. This is compensated for by an activation of the renin-angiotensin-aldosterone system. Reduced urine volumes may cause kidney stones. Both dehydration and renal sodium retention are probably less frequent in patients with ileal pouch-anal anastomosis. Absorption of nutrients in general is not impaired by colectomy. The large intestine salvages energy from malabsorbed organic matter through absorption of the short-chain fatty acids produced in bacterial fermentation. In ileostomy patients, fermentation is negligible, which leads to a significant loss of energy in the ileostomy fluid. Pouches are colonized by a bacterial flora similar to colonic bacteria. In these patients conservation of energy from malabsorbed substrate may be similar to healthy subjects. Resection of ileum and bacterial colonization may lead to malabsorption of vitamin B12 and bile acids. The latter may cause increased incidence of biliary cholesterol stones. Pouchitis is a frequent problem which may be caused by a deficiency of short-chain fatty acids and glutamine in the pouch contents. It is concluded that although the colon is not essential as a digestive organ in man, colectomy results in a number of metabolic changes. The ileal pouch-anal anastomosis may in part substitute for the functions of the large intestine.

Ileostomy output and bile acid excretion after intraduodenal administration of oleic acid

BACKGROUND

Ileostomy output and small-intestinal transport are regulated by complex mechanisms, which the present study aimed to further elucidate.

METHODS

The time-related ileostomy output and bile acid excretion after intraduodenal administration of a fat solution (oleic acid, 3.5 g) was studied in 29 ileostomy patients. Eighteen patients had the entire small bowel preserved (group I), whereas 11 had various lengths of the ileum resected or bypassed (group II).

RESULTS

Intraduodenal fat administration resulted in a prompt and significant increase in ileostomy output in both groups. The accumulated 2-h output after fat administration amounted to 60% of the normal 24-h output in group I and 30% in group II. A marked increase in bile acid excretion preceded the flow response. The fat-induced response was abolished by administration of cholestyramine.

CONCLUSIONS

Bile acids seem to have important regulatory effects with regard to secretion/absorption and transport of small-bowel contents, affecting ileostomy output, with clinical implications in many patients.

Total exchangeable sodium related to body composition in patients with conventional or reservoir ileostomy

Decreased exchangeable body sodium might be a consequence of proctocolectomy and construction of an ileal reservoir. To investigate this, 35 patients with ulcerative colitis and conventional ileostomy were studied before and after conversion to continent ileostomy and compared with 25 unoperated subjects as reference. The sodium urinary excretion varied between 7 and 229 and 1 and 217 mmol/24 h in patients with conventional and reservoir ileostomy, respectively. The total exchangeable sodium was measured and related to body composition estimated from body weight, total body water, and total body potassium. No effect on exchangeable sodium was observed after conversion: 3100 mmol and 2990 mmol, respectively. Patients with ileostomy, regardless of type, did not differ from reference subjects in their exchangeable sodium when related to total body water. A larger variation of total exchangeable sodium related to total body water suggests unstable sodium homeostasis in patients with ileal reservoir compared with reference subjects.

Altered erythrocyte transmembrane transport of sodium and potassium in patients with conventional or reservoir ileostomy

After proctocolectomy, the loss of the colonic absorptive capacity of sodium is compensated for by increased small intestine sodium absorption and renal conservation of Na by enhanced tubular reabsorption. These processes entail increased cellular sodium transport in the enterocytes and in the renal tubular cells. In order to evaluate if there is a general increase in cellular transport of Na after proctocolectomy for inflammatory bowel diseases erythrocyte Na and K contents and the transmembrane Na fluxes were determined in 35 patients with conventional ileostomy, 23 of which were reinvestigated after conversion to continent reservoir ileostomy. A selected group of another 12 patients having high output from their reservoir ileostomy and low urinary Na were studied concomitantly and 33 healthy subjects served as controls. The intracellular Na content did not differ between the groups while the intracellular K levels were higher in patients with conventional or continent ileostomy compared to controls. In addition, the Na influx and the efflux rate constant of Na were both increased after conversion to reservoir ileostomy. Na influx correlated positively with intake and urinary excretion of Na in conventional ileostomy patients. The results suggest that patients with ileostomy have an increased cellular K uptake and that construction of a reservoir ileostomy further alters cell cation transport by increasing the transmembrane Na turnover.

Colonic preservation reduces need for parenteral therapy, increases incidence of renal stones, but does not change high prevalence of gall stones in patients with a short bowel

Forty six patients with less than 200 cm of normal jejunum and no functioning colon were compared with 38 patients with similar jejunal lengths in continuity with a functioning colon. Women predominated (67%), and the most common diagnosis in each group was Crohn's disease (33 of 46 no colon, 16 of 38 with colon). All patients without a colon and less than 85 cm of jejunum and all those with a colon and less than 45 cm jejunum needed long term parenteral nutrition. Six months after the last resection 12 of 17 patients with less than 100 cm jejunum and no colon needed intravenous supplements compared with 7 of 21 with a colon. Between 6 months and 2 years, little change occurred in the nutritional/fluid requirements in either group, though there was weight gain. Of 71 patients assessed clinically at a median of 5 years, none with more than 50 cm of jejunum and a colon needed parenteral supplements. Most (25 of 27) of those without a colon who did not need parenteral supplements required oral electrolyte replacement compared with few (4 of 27) with a colon. None of the patients without a colon developed symptomatic renal stones compared with 9 of 38 (24%) with a colon (p < 0.001). Stone analysis in three patients showed calcium oxalate. Gall stone prevalence was high but equal in the two groups--43% of those without and 44% of those with a colon.

Prophylaxis of uric acid stone in patients with inflammatory bowel disease following extensive colonic resection

Seven patients (13.0%) among 54 patients with inflammatory bowel disease treated by extensive colonic resection were complicated by renal stone. The mean urinary pH value in cases complicated by renal stones (5.3 +/- 0.4) was significantly lower than among those without stones (6.1 +/- 0.3, P less than 0.01). Sodium bicarbonate (4 gm/day, q.i.d.) was given to 11 patients with renal stones and/or hematuria, whose urinary pH was lower than 5.0 or whose urinary sediments were positive for uric acid crystals since Oct. 1985. Their urinary pH and Na concentration increased significantly and no renal stone complication has been seen in the treated group.

Water and electrolyte balance after ileoanal anastomosis

Water and electrolyte balance was studied in 30 patients with ileoanal anastomosis and J pouch, 10 patients with conventional ileostomy, and nine nonoperated patients with quiescent ulcerative colitis. Serum electrolyte concentrations, daily urinary volume, and daily losses of sodium, potassium, and chloride were measured in all patients. Daily fecal weight and daily losses of sodium and potassium were analyzed in patients with ileoanal anastomosis or conventional ileostomy. Serum chloride in patients with ileoanal anastomosis was significantly lower (P less than 0.05) than in those with conventional ileostomy or in nonoperated patients. Daily urinary loss of sodium in nonoperated patients was significantly higher than in patients with ileoanal anastomosis (P less than 0.01) or conventional ileostomy (P less than 0.05). Daily urinary loss of chloride in patients with ileoanal anastomosis was significantly lower (P less than 0.05) than in nonoperated patients. Daily fecal loss of potassium in patients with ileoanal anastomosis was significantly higher (P less than 0.05) than in those with conventional ileostomy. Daily urinary volume and fecal weight did not differ significantly in patients with ileoanal anastomosis or conventional ileostomy. The present study indicates that changes in water and sodium balance after ileoanal anastomosis are similar to those after conventional ileostomy but chloride balance is more altered after ileoanal anastomosis.

Metabolism of body water and electrolytes after surgery for ulcerative colitis: conventional ileostomy versus J pouch

Some authorities believe that patients with conventional ileostomies are chronically water and salt depleted but there are no data on the metabolism of body water and electrolytes after ileoanal J pouch. To clarify the situation we studied the body composition of 14 patients with well functioning ileostomies and 20 patients with well functioning J pouches. Both groups were compared with two closely matched control groups. Body weight, total body fat, fat-free mass, total body water and extracellular water were measured by neutron activation analysis, tritiated water and bromide dilution respectively; 24-h collections of urine and stool were analysed for volume and electrolyte content. The results show that the body content of water and extracellular fluid in ileostomy patients and J pouch patients is normal. The faecal volume and chemistry is similar in both groups resulting in a similar and significant degree of urinary sodium retention.

Prevention of uric acid stone formation by sodium bicarbonate in an ileostomy patient--a case report

A 38 year old female underwent a proctocolectomy and ileostomy for ulcerative colitis in February, 1974. For 8 year post-operatively, she excreted innumerable renal stones, mainly composed of uric acid. Her urine was highly acidic and hyperuricosuric with a low concentration of sodium. Sodium bicarbonate 4 gm/day, t.i.d., was started in October 1985, after which her renal stone excretion completely ceased (up until March, 1987), except for one incidence of stone excretion when she discontinued therapy for a week. During the sodium bicarbonate therapy, her urinary pH and Na concentration were elevated. Furthermore, sodium bicarbonate significantly elevated the urinary pH and Na concentration of other ileostomy patients. Thus, sodium bicarbonate could be used for the possible prophylaxis of uric acid formation in selected ileostomy patients.

Sodium homeostasis after small-bowel resection

In 16 small-bowel-resected patients, 8 with ileostomy and 8 with at least half of the colon in function, plasma volume, plasma aldosterone concentration, plasma renin activity, and the 4-day excretion of sodium and potassium in urine and stools were determined. Patients with ileostomy had a high faecal loss of sodium: 85-181 (median, 149) mmol/24 h, and were all more or less sodium-depleted with decreased plasma volume of 1.4-2.5 (median, 2.0) l/175 cm (normal range, 2.3-3.8l/175 cm), increased plasma aldosterone of 742-2250 (median, 1131) pg/ml (normal range, 33-220 pg/ml), and extremely low sodium excretion in the urine of 0-3 (median, 1) mmol/24 h. Patients with similar small-bowel resection but with at least half of the colon in function had a much smaller faecal sodium loss of 1-66 (median, 8) mmol/24 h. They showed significantly higher plasma volume, 2.2-3.7 (median, 2.6) l/175 cm; normal plasma aldosterone, 25-232 (median, 124) pg/ml; and normal or almost normal sodium excretion in the urine, 49-168 (median, 118) mmol/24 h. Six jejunostomy patients, who sustained a normal or almost normal sodium balance thanks to parenteral saline, had intravenous infusion over 6 h of 1000 ml isotonic sodium chloride with or without aldosterone added. During aldosterone infusion plasma aldosterone increased to the level in the sodium-depleted ileostomy patients. Urinary sodium excretion decreased significantly. Stomal sodium loss did not change. It is concluded that small-bowel resection in ileostomized patients causes excessive faecal sodium loss and results in chronic sodium depletion with severe secondary hyperaldosteronism.(ABSTRACT TRUNCATED AT 250 WORDS)

Marathon without a colon: salt and water balance in endurance running ileostomates

Five trained ileostomates completed a marathon in a cool environment without ill effect. During the race, the ileostomy losses of sodium (1.0-2.7 mmol.h-1) and of water (9.2-19 ml.h-1) were small, but urinary excretion of sodium was very low (0.2-0.75 mmol.h-1) despite drinking a combination of water and glucose-electrolyte solution. The concentration of potassium in the ileostomy discharge tended to increase, also suggesting a sodium retaining state. Healthy ileostomates after suitable training are successful marathon runners, but the prevalence of mild salt depletion in ileostomates generally suggests that it may be advisable for them to take only glucose-electrolyte solutions when competing at any ambient temperature or when preparing for a marathon which is to take place in a warm environment.

Diet and health of people with an ileostomy. 2. Ileostomy function and nutritional state

1. Most subjects who have their large intestine removed and an ileostomy formed lead a healthy life after operation, although they are prone to a variety of metabolic problems. In order to determine the factors likely to lead to these metabolic disturbances a detailed assessment of ileostomy output and composition and of dietary intake in relation to nutritional and metabolic status has been made in a group of ileostomy patients living at home.

2. Thirty-six volunteers with established ileostomies (twenty-six ulcerative colitis (UC) patients and ten, Crohn's colitis (CC) patients) made a 24 h collection of urine and ileostomy effluent and kept a 7 d record of dietary intake and the frequency with which they emptied their ileostomy bag. Blood was collected for haematological and biochemical indices of nutritional status and height, weight and skinfold thickness were measured.

3. Effluent output for the whole group was 760±322 g/day (range 273–1612) and was very closely related to effluent sodium output (R 0·98). Stepwise multiple regression analysis of dietary and other variables identified the amount of ileum resected as the main determinant of both effluent output and effluent sodium. The CC group had significantly greater effluent output (1084±340 g/d) compared with the UC patients (635±215g/d) (P< 0·001); and excreted significantly more nitrogen, carbohydrate and sodium than the UC group.

4. The CC patients particularly showed evidence of salt depletion. The mean (±SD) 24 h urine Na loss for CC patients was 31±30 mmol and for UC patients 67±34 mmol (P< 0·01) with five of the ten CC patientsv. four of the twenty-six patients with UC having raised urinary or plasma aldosterone levels.

5. All subjects had normal haematological and biochemical indices of nutritional status in the blood. Height and percentage body fat were also within the normal range when compared with a control population matched for age, sex and occupation, but patients with an ileostomy weighed on average 4·1 kg less than the controls.

6. These studies show that patients with an ileostomy come within the range of the normal population for most nutritional indices although are at increased risk of salt depletion. Effluent volume, which is probably the determining factor in most metabolic complications of ileostomy, is related more to the extent of the small bowel resection than to diet.

Ileostomy in ulcerative colitis. A questionnaire study of 1,803 patients

A questionnaire regarding details of their illness, social, educational and religious background and various aspects of rehabilitation since surgery was completed by 1,803 persons who underwent ileostomy for ulcerative colitis between 1930 and 1970. The majority of participants were operated on since 1960, reported an above-average education, lived in metropolitan areas, had surgery performed as a single stage proctocolectomy, and were chronically ill for an average of almost 7 years from the onset of disease to ileostomy. An unexplained high incidence of Jewish patients was noted; in addition, Jewish patients comprised almost half of those who had a family history of inflammatory bowel disease. Although some participants reported major postoperative problems including unfavorable alterations in stomal structure and function, bowel obstruction, delayed perineal healing and nephrolithiasis, most patients were satisfied with life with an ileostomy, presently maintaining their health, employment, marriage and sexuality.

Urolithiasis risk factors in continent reservoir ileostomy patients

Conventional ileostomy patients are at an increased risk to urinary stone formation compared to normal controls. This study was designed to evaluate any further risk factors to urinary stone formation in patients with Kock ileostomies. Nine Kock ileostomy patients were matched for age, sex, and body weight with nine conventional ileostomy patients and nine controls. Two 24-hour urine samples from each patient were analyzed for volume, pH, Na+/K+ ratio, oxalate, and uric acid concentration. Both ileostomy groups demonstrated reduced urinary volume and Na+/K+ ratio as compared to the control groups (P less than 0.05). The Kock ileostomy group had the lowest urinary volume. There was no significant reduction in urinary pH or elevation in urine uric acid concentration in the Kock ileostomy group. The results suggest that there is no significantly added risk to uric acid stone formation in Kock ileostomy patients.

The importance of the colon in calcium absorption following small-intestinal resection

The importance of the colon for the absorption of calcium, fat, and fluid was studied in 118 patients with small-bowel resections of various lengths. The patients fell into two groups: 38 with ileostomy and 80 with part of or the whole colon in function. In patients with ileostomy, but not in patients with the colon preserved, the absorption of 47Ca and fluid was inversely correlated to the length of the resected small intestine. In patients with extreme small-bowel resection (greater than or equal to 150 cm) the 47Ca absorption was significantly higher when colon was preserved. In groups of equal small-bowel resections stool mass was significantly higher in patients with ileostomy, but faecal fat was not. However, in both groups faecal fat was correlated to the length of the resected small bowel. The study shows that colon plays an important role for the absorption of calcium after small-intestinal resection and confirms the importance of colon for fluid absorption.

Fluid and electrolyte absorption and renin-angiotensin-aldosterone axis in patients with severe short-bowel syndrome

In eight patients who had received long-term parenteral nutrition because of short-bowel syndrome the need for parenteral supply of fluid, sodium, and potassium was estimated by balance studies. Six patients had jejunostomies. In two, most of the colon was preserved. Jejunostomy patients had a huge stool mass (1710--5270 g, median 2530 g/day) with fixed concentrations of sodium (92 +/- 10 mmol/l) and potassium (15 +/- 4 mmol/l). In contrast, two patients with massive small-bowel resection but with more than half of the colon intact showed almost normal sodium absorption and considerably smaller stool mass (170--510 g/day). Despite apparently good health and normal plasma electrolytes, urea, and haematocrit, four of six jejunostomy patients were sodium-depleted with low plasma volume, low sodium excretion in the urine, and increased plasma renin activity and, in the three most severe cases, increased aldosterone. Even in case of sodium depletion the sodium loss from jejunostomy effluents remained high and presumably unaffected by salt-retaining hormones. The study confirms the importance of preservation of part of the colon for maintenance of fluid and electrolyte balance in patients with extensive bowel resection. Jejunostomy patients who are eating normally may need large parenteral saline supply. Assessment of water and electrolyte homeostasis in these patients requires determination of the urinary sodium excretion and is supported by measurements of plasma renin activity and plasma aldosterone concentration.

Small-bowel adaptation after colectomy in rats

Colectomy with ileoproctostomy or ileostomy was performed in rats. The animals were killed at different time intervals after operation. In histological sections from the small intestine the total crypt cell number and vinblastine-arrested mitoses were counted, and the villus height was measured; these parameters were compared with the corresponding ones in unoperated controls and in rats subjected to ileal transection. After ileoproctostomy the rats remained in good condition, whereas ileostomy was followed by weight loss, debility and a great mortality. After ileoproctostomy, ileostomy and ileal transection there was an increased number of mitoses in the crypts during the 28 days' observation period, indicating an increased rate of cell proliferation. Increased villus height was observed after ileoproctostomy as well as after ileostomy. The mucosal hyperplasia may play a role for the increase in water and salt absorption capacity after colectomy. Probably, however, the hyperplasia of the small-intestinal mucosa cannot fully compensate for the loss of the colon in rats. Preservation of the absorptive function of the rectum, as in ileoproctostomy, is necessary for adequate water and salt absorption.

Cause and management of high volume output salt-depleting ileostomy

Ileostomy function was studied in 12 patients with an established ileostomy following proctocolectomy, in 6 of whom minimal amounts (less than 9 cm) and in 6 significant amounts (30-120 cm, mean 60 cm) of terminal ileum had been removed. Patients who had undergone significant ileal resection had daily faecal volumes considerably greater than those with minimal ileal resection (1202 +/- 284 ml versus 401 +/- 92 ml, P less than 0.001), and also greater daily outputs of sodium (146 +/- 53 mEq versus 43 +/- 12 mEq) and potassium (12.7 +/- 9.0 mEq versus 4.0 +/- 0.99 mEq). The percentage water content of the ileostomy fluid was greater in patients who had had the ileum resected (93.1 +/- 1.8% versus 89.8 +/- 2.5%). In addition, the sodium/potassium ratio in the urine in patients with a properly acting ileostomy after ileal resection was low. It is concluded that when recurrent inflammatory bowel disease, partial small bowel obstruction and intraperitoneal sepsis have been excluded there remains a number of patients whose high ileostomy output is due entirely to the amount of ileum resected. The management of patients with a high output ileostomy with codeine phosphate, Lomotil and oral administration of sodium chloride tablets is discussed.

Long term changes in total body water, total exchangable sodium and total body potassium before and after ileostomy

In 10 patients with inflammatory bowel disease, total body water, total body potassium and total exchangable sodium were measured both before and 6 months after the establishment of a permanent iseostomy. All 10 patients underwent elective surgery for their inflammatory bowel disease but all were malnourished before surgery when their body composition was first measured. Six months later, when the body composition was again determined, all the patients were in good health and had normally functioning ileostomies. As a group they had gained 6-8 kg in body weight and 372 mEq total body potassium over the 6-month period. When the 'normal' total body water was calculated for each patient, a deficit of 12-4 per cent for the group was found before surgery and this was still present (11-1 per cent) 6 months later. The concentration of exchangable sodium in the body water fell from an abnormally high level before surgery to within the normal range 6 months later. These data show that defictis in total body water occurring preoperatively are not repaired in the months following the establishment of a well-functioning ileostomy, and that a reduction of total exchangeable sodium is present in patients with an ileostomy who are otherwise well. It is suggested that these findings should encourage the surgeon managing patients with intractable inflammatory bowel disease to strive for good nutrition and normal body composition before embarking on excisional surgery and the establishment of a permanent ileostomy.

Total body water and total exchangeable sodium in patients after ileorectal anastomosis

Total body water and total exchangeable sodium were measured in 29 patients who had undergone subtotal colectomy with ileorectal anastomosis for chronic ulcerative colitis more than I year previously and in a control group of 28 normal persons. Significant dehydration and sodium depletion in the patients were not demonstrated when compared with the controls. These findings are in contrast to the dehydration and sodium depletion previously demonstrated in ileostomy patients. Faecal loss of sodium in patients with ileorectal anastomosis was found to be less than in patients with ileostomies. The findings suggest that ileorectal anastomosis carries less risk of long-term, fluid and electrolyte depletion than ileostomy.