Metabolic complications of urinary diversions: an overview

Enfortumab Vedotin-induced Hyperglycemia and Ileal Conduit Reconstruction-induced Metabolic Acidosis

We report a 76-year-old man who was treated for hyperglycemia and metabolic acidosis after chemotherapy with enfortumab vedotin and pembrolizumab administered after his surgery for bladder cancer. He had an approximately 20-year history of diabetes. His body mass index was 18.6, and he received metformin 1000 mg/day, sitagliptin 50 mg/day, mitiglinide 30 mg/day, and voglibose 0.6 mg/day with hemoglobin A1c was approximately 7%. He underwent total cystectomy and ileal conduit reconstruction. After relapse, he received chemotherapy but later developed hyperglycemia and metabolic acidosis. His hyperglycemia was caused by enfortumab vedotin, and metabolic acidosis was attributable to the ileocecal canal. These symptoms should be remembered as important complications of this standard treatment, which prompted this case report.

Urinary Diversion and Metabolic Acidosis: A Case Report

Urinary diversion, a surgical technique to redirect urine usually after cystectomy, and its complications are potential challenges to physicians and early recognition decreases mortality and morbidity. A 45-year-old male with a history of type 2 diabetes mellitus and hypertension for over three years underwent urinary diversion as a treatment for invasive bladder cancer and was discharged ambulatory with an indwelling Foleys catheter. The patient returned to the emergency room with a primary complaint of hematuria. The patient was noted to be frail-looking, dehydrated and tachycardic. Laboratory results yielded an acute kidney injury reflected by the elevated creatinine, hyperkalemia and a venous blood gas demonstrating a hyperchloremic metabolic acidosis. The patient had bilateral distended renal calyces by ultrasound and irrigation of bladder through a three-way Foley showed to have large thick clots. The patient was admitted under the surgical intensive care unit after involving appropriate sub-specialties. The patient was started on sodium bicarbonate infusion, broad-spectrum antibiotics and a urinary catheter in place to monitor urine output. The patient's acidosis steadily improved with correction of his laboratory parameters, transferred out of ICU and the remaining stay in the medical ward was uneventful. The purpose of this case report is to help demonstrate the association between urinary diversion and the type of acidosis that subsequently develops in relation to this surgical procedure.

Hyperchloremic normal gap metabolic acidosis

Metabolic acidosis is defined as a pathologic process that, when unopposed, increases the concentration of hydrogen ions (H+) in the body and reduces the bicarbonate (HCO3-) concentration. Metabolic acidosis can be of a kidney origin or an extrarenal cause. Assessment of urinary ammonium excretion by calculating the urine anion gap or osmolal gap is a useful method to distinguish between these two causes. Extrarenal processes include increased endogenous acid production and accelerated loss of bicarbonate from the body. Metabolic acidosis of renal origin is due to a primary defect in renal acidification with no increase in extrarenal hydrogen ion production. This situation can occur because either the renal input of new bicarbonate is insufficient to regenerate the bicarbonate lost in buffering endogenous acid as with distal renal tubular acidosis (RTA) or the RTA of renal insufficiency, or the filtered bicarbonate is lost by kidney wasting as in proximal RTA. In either condition, because of loss of either NaHCO3 (proximal RTA) or NaA (distal RTA), effective extracellular volume is reduced and as a result the avidity for chloride reabsorption derived from the diet is increased and results in a hyperchloremic normal gap metabolic acidosis. The RTA of renal insufficiency is also characterized by a normal gap acidosis, however, with severe reductions in the glomerular filtration rate an anion gap metabolic acidosis eventually develops.

Metabolic and Nutritional Consequences of Urinary Diversion Using Intestinal Segments to Reconstruct the Urinary Tract

Intestinal segments in various forms have been used to reconstruct the urinary tract since the mid-1800s. Currently, many different forms of continent and incontinent diversion options exist. Incorporating bowel mucosa within the urinary tract leads to predictable metabolic and nutritional consequences. The use of ileum or colon can cause a hyperchloremic metabolic acidosis, vitamin B12 deficiency, osteoporosis, fat malabsorption, urinary calculi, and ammoniagenic encephalopathy. Due to metabolic and nutritional consequences associated with the use of jejunum and gastric segments, the use of these bowel segments is not recommended.

Ileal Neobladder: An Important Cause of Non-Anion Gap Metabolic Acidosis

BACKGROUND

The differential diagnosis for a non-anion gap metabolic acidosis is probably less well known than the differential diagnosis for an anion gap metabolic acidosis. One etiology of a non-anion gap acidosis is the consequence of ileal neobladder urinary diversion for the treatment of bladder cancer.

CASE REPORT

We present a case of a patient with an ileal neobladder with a severe non-anion gap metabolic acidosis caused by a urinary tract infection and ureteroenterostomy. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Part of the ileal neobladder surgery includes ureteroenterostomy and predisposes patients to several clinically significant metabolic derangements, including a non-anion gap metabolic acidosis. These patients have an increased chronic acid load, bicarbonate deficit, and hypokalemia, which should be appreciated when resuscitating these patients.

We can rebuild it: reconstructive solutions for structural urologic diseases

Bladder augmentation and urinary diversion have become standard of care as surgical treatments for structural and functional disorders affecting the bladder, both in children and adults. With improved medical care, long-term survival of these patients is expected. Common medical problems that can occur such as metabolic side effects including acid-base imbalances and nutritional issues need to be anticipated and addressed. In addition, surgical problems caused by impaired urinary drainage, namely stones and urinary tract infections, and mechanical factors related to catheterizable channels and continence also may compound postoperative management. The risk of malignancy after bladder augmentation and substitution, and appropriate surveillance for this, remains to be clearly defined.

Etiologic and therapeutic analysis in patients with hypokalemic nonperiodic paralysis

BACKGROUND

Hypokalemic nonperiodic paralysis represents a group of heterogeneous disorders with a large potassium (K(+)) deficit. Rapid diagnosis of curable causes with appropriate treatment is challenging to avoid the sequelae of hypokalemia. We prospectively analyzed the etiologies and therapeutic characteristics of hypokalemic nonperiodic paralysis.

METHODS

Over an 8-year period, patients with hypokalemic nonperiodic paralysis were enrolled by excluding those with hypokalemic periodic paralysis due to acute shift of K(+) into cells. Blood and spot urine samples were collected for the measurements of electrolytes, pH, and biochemistries. Intravenous potassium chloride (KCl) at a rate of 10-20 mmol/h was administered until muscle strength recovered.

RESULTS

We had identified 58 patients with hypokalemic nonperiodic paralysis from 208 consecutive patients with hypokalemic paralysis, and their average K(+) concentration was 1.8 ± 0.2 mmol/L. Among patients with low urinary K(+) excretion (n = 17), chronic alcoholism, remote diuretic use, and anorexia/bulimia nervosa were the most common causes. Among patients with high urinary K(+) excretion (n = 41) and metabolic acidosis, renal tubular acidosis and chronic toluene abuse were the main causes, while primary aldosteronism, Gitelman syndrome, and diuretics were the leading diagnoses with metabolic alkalosis. The average KCl dose needed to restore muscle strength was 3.8 ± 0.8 mmol/kg. Initial lower plasma K(+), volume depletion, and high urinary K(+) excretion were associated with higher recovery KCl dosage. During therapy, patients with paradoxical hypokalemia (n = 32) who required more KCl supplementation than patients without (4.1 ± 0.7 vs 3.4 ± 0.7 mmol/kg, P < 0.001) often exhibited significantly higher plasma renin activity and received a higher volume of normal saline before its appearance.

CONCLUSIONS

Understanding the common etiologies of hypokalemic nonperiodic paralysis may aid in early diagnosis. Patients with initial lower plasma K(+), renal K(+) wasting, and hypovolemia required higher recovery K(+) dosage. Paradoxical hypokalemia is prone to develop in hypovolemic patients even during K(+) supplementation with volume repletion.

An unrecognised case of metabolic acidosis following neobladder augmentation cystoplasty

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Hyperchloraemic metabolic acidosis is a well established complication following urinary diversion.

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Patients with orthotopic neobladder with high residual urine and large capacity are at particular risks.

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A delay in the diagnosis can lead to significant morbidity.

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The risks of metabolic acidosis should be clearly documented on discharge to ensure early recognition by non-specialists.

Introduction

Presentation of case

Discussion

Conclusion

Retubularization of the ileocystoplasty patch for conversion into an ileal conduit

INTRODUCTION

We present the outcomes and long-term follow-up of patients who underwent conversion to an ileal conduit urinary diversion using the retubularized patch from the initial augmentation ileocystoplasty.

METHODS

We reviewed the charts of all patients who underwent this surgery at our centre. The indications for surgery, workup, clinical outcomes and complication rates were assessed. Patient-reported symptom response based on global response assessment (GRA) was determined and used as a subjective measure of overall treatment effectiveness.

RESULTS

Thirteen patients with either bladder pain syndrome/interstitial cystitis (BPS/IC) (n = 11) or neurogenic bladder (n = 2) were followed for a mean of 80 months. The most common indication for surgical conversion was persistent lower urinary tract symptoms (LUTS) or bladder pain. Late complications were frequent, typically low-grade, and usually manageable with conservative therapy; the most common were urinary tract infections (n = 6) and parastomal hernias (n = 5). Two patients developed ureteric strictures. Nine of 13 patients required additional surgery to manage complications or persistent symptoms. Only 5 of 11 GRA respondents reported a successful therapeutic outcome and BPS/IC patients who underwent concurrent cystourethrectomy tended to be most satisfied (2/3). Nevertheless, several patients still achieved symptom control when no other treatment options were available to them.

CONCLUSION

Conversion to an ileal conduit using the retubularized ileocystoplasty patch offers several technical and therapeutic advantages over creating a urinary diversion from a new bowel segment. It should therefore be considered a viable treatment option in patients who have exhausted more conservative management of their LUTS.

Valproic Acid-induced hyperammonemia in the elderly: a review of the literature

Valproic acid and its derivatives are commonly used to treat many psychiatric conditions in the elderly. Hyperammonemia is a less common but important side effect of these drugs. The elderly patient appears highly vulnerable to this side effect of this group of medications. In this paper, we systematically review the published literature for hyperammonemia induced by valproic acid and its derivatives. We describe the three reported cases and review possible treatment strategies for this condition.

Severe metabolic acidosis and hypokalemia in a patient with enterovesical fistula

We report a case of a 59-year-old woman who had severe metabolic acidosis and hypokalemia due to an enterovesical fistula. The patient came to our hospital complaining of systemic weakness and numbness of the fingers. She was found to have hyperchloremic metabolic acidosis (arterial bicarbonate, 2.8 mEq/l) and hypokalemia (serum potassium, 1.9 mEq/l) and was admitted for treatment. Following the correction of metabolic acidosis and hypokalemia, the patient was examined for the underlying cause of these electrolyte and acid-base disorders. She had a history of total hysterectomy followed by radiotherapy due to uterine cancer 30 years previously. After the surgery, she had suffered postoperative neurogenic bladder dysfunction, necessitating intermittent self-catheterization. Two years before admission, she had begun to experience watery diarrhea. A radiographic study after recovery from the acid-base and electrolyte disorders revealed the presence of an enterovesical fistula. The fistula was surgically resected and the metabolic acidosis completely cleared. Unexplained hyperchloremic metabolic acidosis with hypokalemia may suggest the presence of an enterovesical fistula in patients with a surgical history of malignant pelvic tumor and neurogenic bladder dysfunction.

Urinary diversion after radical cystectomy

At most centers with experience in urinary diversion, an orthotopic urinary reservoir is the diversion of choice after radical cystectomy for bladder cancer. The paradigm has shifted in the past 10 years from actively looking for reasons to do an orthotopic diversion to carefully considering why a patient cannot undergo reconstruction to their native urethra. In our institution, any patient who is to undergo a radical cystectomy for bladder cancer is a potential candidate for orthotopic diversion provided they do not have chronic renal insufficiency. In addition, they must have a negative urethral margin on frozen section at the time of cystectomy, and have the mental and physical capacity to understand what is required to manage the reservoir after surgery. Proper patient selection is the key to success. Notably, chronologic age is not an absolute contraindication to orthotopic diversion. Instead, careful consideration of the patient's comorbid conditions should guide eligibility. In addition, locally advanced disease is not a contraindication to an orthotopic diversion. To have the flexibility to manage whatever situation presents itself intraoperatively, the surgeon performing a urinary diversion after radical cystectomy must be facile with several diversion techniques. At the very least, the surgeon must be comfortable with one type of each major form of urinary diversion, a conduit (incontinent) diversion, a continent cutaneous diversion, and an orthotopic diversion. As a result, radical cystectomy and urinary diversion should be performed at centers with significant experience in all three types of diversions.

Metabolic changes and urodynamic findings after continent urinary diversion

Methods of creating continent urinary diversions were developed in the mid-1980s (neobladder, pouch) providing patients with continence and anatomically appropriate voluntary urine discharge. In a follow-up investigation on 18 patients, the question to be clarified was whether continent urinary diversion meets the demands of an ideal bladder substitute. Follow-up examination showed normal clinical test values almost without exception. Only five out of 18 patients had discrete acidosis. Neither malabsorption syndrome nor any disorder of vitamin D3 metabolism was found. Ultrasonography and X-ray diagnostics showed normal conditions, without stones and reflux. Urodynamic investigations revealed that bladder emptying was almost free of residual urine, and continence was largely undisturbed. In accordance with these data, there is almost perfect patient acceptance. At present, there are still no sufficient data on the risk of tumour induction, since the latency period required (about 20 years) in most cases has not yet been reached. Since there are currently numerous publications on "urinary diversion carcinoma", consistent follow-up is necessary comprising not only the metabolic, but also the oncological risks of urinary diversion via intestinal segments.