Hypokalaemic quadriparesis in a patient with urinary diversion through Indiana pouch
- 1 General Medicine, KS Hegde Medical Academy, Mangalore, Karnataka, India
- 2 Nephrology, KS Hegde Medical Academy, Mangalore, Karnataka, India
- Correspondence to Dr Srinivasa Anurag Kuchulakanti; anuragkuchulakanti@gmail.com
Abstract
A man in his 20s, a patient with chronic kidney disease with a baseline estimated glomerular filtration rate of 33 mL/min/1.73 m2, who had an Indiana pouch continent urinary diversion procedure done at 6 years of age for bladder exstrophy, presented to the emergency room with sudden-onset progressive quadriparesis over 6 hours with power 1/5 in all the limbs with preserved reflexes. He was fully conscious and oriented, with stable vital signs. On evaluation, he had severe hypokalaemia and severe metabolic acidosis (both high anion gap and non-anion gap acidosis). Imaging studies showed bilateral gross hydroureteronephrosis, and renal and pouch calculi. Hypokalaemia was promptly treated with intravenous potassium chloride and acidosis with emergency haemodialysis. The patient had a complete motor recovery following intravenous potassium correction and was discharged with oral potassium and bicarbonate supplements. Here, the Indiana pouch, its metabolic and electrolyte complications, and its treatment are discussed.
Background
Urinary diversion procedures are done in patients where the native bladder is excised, as seen in bladder cancers, cervical cancers with bladder involvement, congenital anomalies including bladder exstrophy, neurogenic bladders and interstitial cystitis. The urine is diverted to a reservoir, usually made up of a bowel segment. There are several different types of urinary diversion procedures with different types of reservoirs used. The Indiana pouch is one such type of urinary diversion procedure. It was one of the most popular continent urinary diversion procedures in the 1990s. It involves the use of the right colon as the reservoir, the ileum as the conduit to the exterior on the right side of the anterior abdominal wall, the intact ileocecal valve for continence, and tunnelled ureteral implantation for antireflux.1 As this is a continent urinary diversion pouch, the patient has to intermittently catheterise the pouch to drain the collected urine in the reservoir. This procedure is associated with postoperative complications like pouch leak, incontinence, obstruction, reflux, calculus formation, electrolyte imbalances and acid-base disorders.2 These complications may present soon after the procedure or years later. Hence, it is important to know about these complications in order to detect them early during the follow-up of patients and to prevent them if possible.
Case presentation
A man in his 20s, a patient with known chronic kidney disease (CKD) with a baseline creatinine of 2.56, estimated glomerular filtration rate of 33 mL/min/1.73 m2, who underwent Indiana pouch repair for bladder exstrophy at 6 years of age, presented to the emergency room with a history of sudden-onset progressive loss of motor power of all four limbs and trunk over a period of 6 hours with preserved reflexes. Cranial nerves were also affected, resulting in slurring of speech. He also had two episodes of vomiting after the onset of weakness. No history of trauma. No history of preceding fever, or acute or chronic diarrhoea. On examination, the patient was fully conscious and oriented. Vital signs were stable. A neurological examination revealed a loss of power in all the limbs to 1/5. Cardiac, respiratory, and abdominal systemic examinations were unremarkable.
Investigations
The patient’s initial lab workup revealed him to have severe hypokalaemia (K+: 2.03 mmol/L) and severe metabolic acidosis(pH: 6.95). A 12-lead standard ECG was done and showed prominent U waves in the precordial leads V2 and V3 (figure 1). The rest of the reports is as mentioned in table 1.
12-Lead standard ECG shows prominent U waves in leads V2 and V3. aVR, agumented vector right; aVL, augmented vector left; aVF, augmented vector foot.
Laboratory investigations and blood gas analysis done
| Labs | Day 1 | Day 2 | Day 3 | Day 4 | Day 5 | Reference range |
| Hb (g/L) | 160 | 130–170 | ||||
| TC (c/cumm) | 13 300 | 4000–11 000 | ||||
| PLT (c/cumm) | 213 000 | 150 000–400 000 | ||||
| Na (mmol/L) | 138 | 137 | 136–145 | |||
| K (mmol/L) | 2.03 | 1.88 | 3.05 | 4.83 | 4.23 | 3.5–5.1 |
| Urea (mg/dL) | 97.6 | 16.6–48.5 | ||||
| Creat (mg/dL) | 4.20 | 3.82 | 4.53 | 0.7–1.4 | ||
| Ph | 6.95 | 7.09 | 7.13 | 7.35–7.45 | ||
| PCo2 (mm Hg) | 25 | 29 | 24 | 30–40 | ||
| PO2 (mm Hg) | 117 | 120 | 124 | 35–45 | ||
| HCO3 (mmol/L) | 5.5 | 8.8 | 8.0 | 22–27 | ||
| SPO2 | 95 | 97 | 97 | >92 | ||
| Lact | 0.5 | 0.6 | 0.5 | |||
| Cl (mmol/L) | 112 | 111.5 | 98–107 | |||
| Mg (mg/dL) | 2.56 | 1.6–2.6 | ||||
| Ca (mg/dL) | 8.0 | 8.6–10 | ||||
| TSH (ulU/mL) | 2.36 | 0.27–4.2 | ||||
| Urine K (mmol/L) | 16.5 | |||||
| RBS (mg/dL) | 98 |
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Ca, calcium ion; Cl, chloride ion; Creat, creatinine; Hb, haemoglobin; HCO3, bicarbonate ion; K, potassium ion; Lact, lactate levels; Mg, Magnesium ion; Na, Sodium-ion; pCO2, partial pressure of arterial carbon dioxide; pH, potential of hydrogen; PLT, platelet count; pO2, partial pressure of arterial oxygen; RBS, random blood sugar; SPO2, oxygen saturation; TC, total counts; TSH, thyroid stimulation hormone.
On evaluation, he was found to have severe mixed metabolic acidosis with high anion gap metabolic acidosis and normal anion gap metabolic acidosis (figure 2). For evaluation of hypokalaemia, serum TSH and serum magnesium were sent and were normal. The serum calcium level was 8 mg/dL. Though a urine analysis is not accurate as the urine is technically not from the bladder, it was done and showed a urinary K+of 16.5 mmol/L. Ultrasound sonography of the abdomen and CT showed bilateral hydroureteronephrosis, calculus in the reservoir of the Indiana pouch and a left renal calculus (figures 3–5).
Stepwise analysis of the patient’s initial ABG (A). Pictorial representation of the anion gap (AG) in a normal state, a high AG in high AG metabolic acidosis, and a high AG in a mixed high AG and non-AG metabolic acidosis. Note that only the values in the mixed high AG and non-AG metabolic acidosis are of the patients (B). This image has been created by the author. ABG, atrerial blood gas analysis; pCO2, partial pressure of carbon dioxide.
CT image of the patient at the level of the kidneys showing bilateral hydroureteronephrosis. LK, left kidney; RK, right kidney.
CT image of the patient showing the reservoir of the Indiana pouch as labelled filled with urine.
CT image of the lower part of the Indiana pouch with calculus in situ.
Differential diagnosis
With the given acute presentation of quadriparesis and a history of urinary diversion procedure and pre-existing CKD, quadriparesis secondary to hypokalaemia was considered the first differential diagnosis. Guillain-Barré syndrome (GBS) was a close differential but was ruled out due to preserved deep tendon reflexes. Laboratory workup revealing hypokalaemia helped to rule in diagnosis against other causes of acute quadriparesis like neuromuscular junction disorders, GBS and channelopathies. Renal tubular acidosis can also present with hypokalaemia and metabolic acidosis.
Treatment
The patient was immediately treated with intravenous potassium chloride through central venous access at 60 mEq/hour for the correction of hypokalaemia. In view of severe metabolic acidosis, the patient had one haemodialysis session.
Outcome and follow-up
After treatment, the acidosis improved and potassium levels normalised. The patient regained motor power in all the limbs and trunk over 2 days of intravenous potassium correction. The patient had regained full motor power in the course of 5 days and was discharged with oral potassium chloride of 15 meq three times per day and bicarbonate supplementation of 500 mg two times per day. During follow-up after 2 weeks, he was completely asymptomatic and had normal laboratory parameters.
Discussion
The Indiana pouch may lead to several complications, including diarrhoea, malabsorption, acid-base abnormalities, electrolyte abnormalities, calculus formation, hyperammonaemia encephalopathy, vitamin B12 deficiencies, demineralisation of bone and worsening of renal function.3
Acid-base abnormalities occur when the systemic arterial pH is not maintained in the normal range of 7.35–7.45 by the extracellular and intracellular chemical buffering systems by the respiratory and renal regulatory systems. Metabolic acidosis occurs because of an increase in endogenous acid production, loss of bicarbonate or accumulation of endogenous acids because of an inappropriately low excretion of acid by the diseased kidneys. In this patient, the high anion gap acidosis is due to the accumulation of acidic anions due to acute renal failure.
In patients where ileal or colonic segments are used for urinary diversion as in Indiana pouch patients usually tend to develop a hyperchloraemic metabolic acidosis as the bowel epithelial cells have a chloride ion/bicarbonate ion (Cl-/ HCO3-) exchanger which is quite metabolically active. As the urine is in prolonged contact with the epithelial cells of the reservoir, the chloride ions are absorbed and bicarbonate ions are secreted. This loss of bicarbonate ions with chloride accumulation results in hyperchloraemic metabolic acidosis. As a result of this metabolically active luminal wall, there is always a chronic acid load. This chronic metabolic acidosis is present in 70% of the patients with urinary diversions, but only 1% of them develop severe metabolic acidosis.4 Concomitant reduced renal functions further predispose the patients to severe metabolic acidosis. Colonic reservoirs are more prone to acidosis as compared with ileal reservoirs.
As reported in previous studies, electrolyte disturbances seen with urinary diversion procedures include hypokalaemia, hypocalcaemia and hypomagnesaemia.2 4 5 Though electrolyte abnormalities in urinary diversion procedures have been reported in many different studies, no long-term epidemiological studies have been done to determine the incidence of these abnormalities. Hypokalaemia is caused by both intestinal as well as renal loss. The intestinal loss of K+ is much less common with ileal as compared with sigmoid diversions. The renal loss of potassium is due to systemic acidosis. Metabolic acidosis is associated with decreased net proximal Na+ reabsorption. The subsequent increase in distal delivery leads to volume contraction and activation of the renin–angiotensin–aldosterone system (RAAS). The RAAS might also be activated by the inappropriate loss of HCO3- salts generated by the intestinal segment. The combination of increased distal Na+ delivery and aldosterone increases renal K+ excretion. This hypokalaemia is important and must be recognised as this uncorrected hypokalaemia might worsen while correcting metabolic acidosis. This is because when there is a slow development of extracellular acidosis over some time, the H+ ions that are in excess extracellularly enter the cells in exchange for K+ ions in an attempt to maintain electroneutrality, and during rapid correction of acidosis, the H+ ions leave the cells in exchange for K+ ions. This leads to a rapid intracellular shift of the K+ ions and a worsening of hypokalaemia if present. Clinically, hypokalaemia becomes apparent as muscle weakness, sometimes so profound as to be mistaken for GBS, as reported in the literature previously. Hypocalcaemia is caused by renal wasting as well as depletion of the body’s stores. The body’s stores of calcium carbonate in bones are mobilised during the buffering of the chronic acidotic state, and the excess calcium is cleared by the kidneys. Hypomagnesaemia is a rare form of electrolyte abnormality caused in part due to renal wasting and due to nutritional deficiency.
Finally, patients with urinary diversion are prone to calculus formation, especially upper tract calculus of the struvite type. Chronic bacteriuria with urease-producing organisms and upper urinary tract dilatation associated with urinary stasis are two important causes of the development of renal calculi. After 20 years of follow-up, up to 20% of patients with ileal conduits will have renal calculi. Pouch calculi are reported in about 10% of patients with continent diversion.2 Initially, due to the presence of exposed staples, there was a high incidence of pouch calculus formation.
In our case, after the recognition of hypokalaemia and severe mixed metabolic acidosis with components of both high anion gap and normal anion gap over the background of CKD with reduced renal function, the patient was started promptly on intravenous potassium correction with 60 mEq/hour through central venous access. The mixed metabolic acidosis is due to high anion gap acidosis due to renal failure and normal anion gap acidosis due to hyperchloraemia. The patient underwent one session of haemodialysis in view of severe metabolic acidosis (pH- 6.9). Intravenous potassium supplementation was continued for 2 days, followed by oral supplementation. Oral bicarbonate supplementation was increased to a higher dose of 500 mg two times per day as he was already on sodium bicarbonate supplementation of 300 mg two times per day for his CKD. Over the course of 5 days, the patient made a full motor recovery with no residual motor weakness. He was discharged with oral potassium chloride 15 meg three times per day and sodium bicarbonate 500 mg two times per day supplementation and was advised frequent urinary reservoir emptying. As this was his first time having this complication, the patient and his family members were educated about all the possible metabolic complications and their clinical manifestations. He was planned for endoscopic pouch evaluation given the development of calculus in the pouch at a later date.2
In a case report by Dsouza and Hussein, a 45-year-old patient who had muscle-invasive bladder carcinoma underwent a urinary diversion procedure in the form of a Studer pouch and was discharged only to be readmitted 3 days after discharge when he presented with haematuria, looking ill, tachycardic and dehydrated.6 He was diagnosed with acute kidney injury and hyperchloraemic metabolic acidosis. The patient was promptly treated to correct his metabolic parameters and he improved. Their case report highlights the metabolic complications of urinary diversion in the early postoperative period.
In a case report by Niwa et al, a 65-year-old man who underwent urinary diversion with bilateral ureterosigmoidostomy for bladder carcinoma 16 years ago presented with weakness of all four limbs, similar to the patient in our case report.5 He was diagnosed with hypokalaemia and severe metabolic hyperchloraemic acidosis. Treatment with intravenous potassium and sodium bicarbonate resulted in improvement in metabolic parameters and improvement of quadriparesis. The treatment of metabolic parameters resulted in the recovery of quadriparesis similar to that of our case.
There are several limitations to our study. A quantitative evaluation of muscle power at presentation and after recovery was not done. Second, even though the temporality of events indicates the patient’s symptoms were related to hypokalaemia, as suggested by the fact that the symptoms improved on normalisation of electrolytes, other causes of quadriparesis were not ruled out. Early GBS can present with quadriparesis with intact deep tendon reflexes, although reduced, so it would have been prudent to perform a lumbar puncture to rule out GBS.
Patient’s perspective
It was a pretty scary experience from the beginning. Life was going on as usual, and 1 day in the morning, around 10 a.m., I started noticing difficulty in getting up from bed. I didn’t give it much thought, but soon noticed the weakness spreading to involve both my legs and my hands. I started getting really worried when I was not able to move my legs or my arms completely and alerted my father. He immediately rushed me to the hospital. On the way to the hospital, I started developing nausea and vomiting once. This got me really anxious and I started guilt-tripping, thinking it was all my fault as I delayed emptying my bladder this morning. Once I reached the hospital, the doctors ran some blood tests and told me not to worry, and that I might regain the ability to move my body with treatment. They told me I needed to undergo emergency dialysis to remove excess acid levels built up in my body and also need urgent treatment for low potassium levels in my body. This gave me hope and the courage to carry on forward. They started treatment, and I underwent dialysis. By night time, my nausea had settled and I was feeling a little better. The next morning, I was able to move my fingers and was soon regaining power. By the second day, I was able to sit up and move my hands and legs. It was a big relief to me as the treatment seemed to be working. The doctors then got a scan done and told me I had a small stone in my urinary pouch, but it’s nothing to be worried about at the moment, so I thought I would get it treated later. The doctors mentioned that due to my surgical pouch, I’m more prone to developing some complications and that I should be on the lookout for alarming symptoms and reach out immediately to the hospital in case such things ever happen again.
Learning points
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Urinary diversion procedures are associated with surgical as well as non-surgical complications. Complications can occur early or late after the procedure, sometimes even several years postprocedure.
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Electrolyte imbalances, including hypokalaemia, can be seen in patients with urinary diversion and can present with motor weakness, sometimes severe enough to mimic Guillain-Barre syndrome.
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The majority of patients with urinary diversion procedures have a low level of underlying acid-base disorder, with 1% of them developing severe metabolic acidosis. Hyperchloraemic metabolic acidosis is the most common acid-base disorder encountered in patients with the Indian pouch.
Ethics statements
Patient consent for publication
Footnotes
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Contributors Dr.Anurag Kuchulakanti is a postgraduate in the department of general medicine, and Dr.Pradeep M Shenoy is a chief consultant and head of the unit in the department of nephrology. The patient in this case report was admitted under PMS and AK carried out the treatment plans after discussing with PMS. It was PMS idea to submit this case as a case report. AK followed through with the idea and did the data collection, data analysis, drafting of the article. PMS contributed to the critical revision of the article and final approval of the version to be uploaded. The British Medical Journal was selected by AK for the publication of this case report as it provides clinicians across the globe the clinical information about this interesting case.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.
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