Hyperammonemia-induced encephalopathy: A rare devastating complication of bariatric surgery

Nonhepatic hyperammonemic encephalopathy following bariatric surgery: A systematic review

BACKGROUND

Nonhepatic Hyperammonemic encephalopathy (NHAE) following Bariatric Surgery (BS), mainly Roux-en-Y Gastric Bypass (RYGB) and Biliopancreatic Diversion (BPD) is a potentially devastating condition if not diagnosed and managed promptly.

METHODS

A literature review was performed using PRISMA guidelines. Eighteen studies and 3 conference abstracts with a total of 33 patients were included in this review.

RESULTS

Majority (28 patients, 84.8 %) had RYGB. Seven patients (21.2 %) had associated metabolic disorders. 60 % of patients presented with neurological symptoms or signs such as confusion, cognitive and/or psychomotor changes, and decreased reflexes. Two patients presented with status epilepticus. In 30 of the 33 patients an elevated serum ammonia levels was reported (90.9 %). The overall mortality was 39.3 %.

CONCLUSION

NHAE is a rare condition following bariatric surgery (in particular bypass procedures), carrying a high mortality rate. The signs and symptoms are predominantly neurological and may be mistaken for Wernicke's encephalopathy or other more common neurological conditions. Serum ammonia levels should be checked in those who present with these symptoms and signs. Prompt treatment might be life saving in patients with NHAE.

Dry Beriberi Post Roux-en-Y Gastric Bypass Surgery

Bariatric surgery is an effective strategy for achieving substantial weight loss, prolonging survival, and improving the comorbidities associated with obesity. Nutritional deficiency is a commonly recognized post-procedural complication. Here, we present a case of a patient with paresthesia, lower extremity weakness, and altered mental status one year following Roux-en-Y gastric bypass, who was found to have multiple vitamin and micronutrient deficiencies and was diagnosed with beriberi in the setting of profound thiamine deficiency.

Hyperammonemia in the setting of Roux-en-Y gastric bypass presenting with osmotic demyelination syndrome

Hyperammonemia can lead to serious outcomes including brain herniation, coma and death. It is often attributed to liver disease, specifically in association with alcohol use. However, in the absence of liver pathology, it can be difficult to diagnose the etiology. We present a case of a patient with a history of remote alcohol use disorder in remission and Roux-en-Y gastric bypass (RYGB) 20 years prior who was admitted for altered mental status, found to have hyperammonemia with normal liver function tests and a normal liver biopsy. An extensive workup was unremarkable until several weeks into her admission, where she was found to have osmotic demyelination syndrome on head MRI, which was obtained after she developed persistent myoclonus and opsoclonus. Her osmotic demyelination was speculated to be secondary to hyperammonemia, which itself was correlated to her history of RYGB. There have been multiple case reports on the association of late onset hyperammonemic encephalopathy after RYGB; however, no significant correlation has yet to be made between osmotic demyelination syndrome and hyperammonemia.

Nonhepatic hyperammonemic encephalopathy complications following bariatric surgery: a case report and review of the literature

Background

Hyperammonemic encephalopathy, a rare but fatal condition, is increasingly being reported as a possible complication of bariatric surgery. Here, we present a case of hyperammonemic encephalopathy, focusing on the clinical presentation, diagnostic measures, and our treatment methods, which resulted in a rare favorable outcome, emphasizing the unique role of renal replacement treatment. We also provide a detailed discussion of the mechanism through which hyperammonemia occurs secondarily to bariatric surgery.

Case presentation

A 44-year-old Moroccan Jew woman with a history of obesity presented in the hospital with urea cycle disorder that manifested after bariatric surgery. A rapid diagnostic process, together with conservative treatment with lactulose, nutritional supplementation, dietary protein restriction, and ammonia scavengers did not result in adequate improvement. Therefore, hemofiltration was performed, which yielded a favorable outcome.

Conclusions

The case findings indicate an association between hyperammonemic encephalopathy and bariatric surgery, and support early treatment with ammonia scavengers, as currently accepted. Nevertheless, if rapid improvement is not seen, it is advisable to consider hemodialysis or hemofiltration as early invasive strategies.

Use of Lactulose to Treat Hyperammonemia in ICU Patients Without Chronic Liver Disease or Significant Hepatocellular Injury

OBJECTIVES

To review ICU patients with elevated ammonia without a clear hepatic etiology, to compare outcomes between those who received lactulose and those who did not.

DESIGN

Retrospective observational study.

SETTING

Medical, surgical, and subspecialty intensive care units at Wake Forest Baptist Medical Center, Winston-Salem, North Carolina between December 2012 and August 2016.

PATIENTS

Adults with ammonia levels above 50 μmol/L, excluding those with known chronic liver disease, inborn error of metabolism, active use of valproic acid, total bilirubin ≥ 2 μmol/L, or alanine aminotransferase ≥ 100 units/L.

INTERVENTIONS

Comparison in ICU length of stay (LOS), hospital LOS, in-hospital mortality, and mortality at 30 and 90 days.

MEASUREMENTS AND MAIN RESULTS

Criteria for inclusion were met in 103 cases. Mean ammonia level was 75 μmol/L, with undetermined etiology in the majority of subjects. Lactulose was given in 48 cases (46.6%), with a median of 9.5 doses given. There were no significant differences in outcomes between the lactulose and non-lactulose groups. Among subjects with multiple data points, lactulose did not have a dose-dependent effect on ammonia level, and was not associated with faster ammonia normalization compared to non-lactulose. When analyzed separately, patients with moderate hyperammonemia (60-99 μmol/L) who received lactulose had longer hospital and ICU length of stay compared to non-lactulose (417.8 hours vs. 208.4 hours, P = 0.003, and 229.2 hours vs. 104.7 hours, P = 0.025; respectively), though confounders were present.

CONCLUSIONS

Routine use of lactulose to treat mild to moderate hyperammonemia in this patient population was not associated with improved outcomes.

Russian Consensus “Hyperammonemia in Adults” (Version 2021)

Justification Given the large number of reports on the peculiarities of liver lesions during the Sars-Cov-2 infection [1], a team of experts who participated in the 23rd Congress of the Scientific Society of Gastroenterologists of Russia and 15 National Congress of Therapists of November 19, 2020 decided to make additions to the Russian Consensus of “Hyperammonemia in Adults” published early 2020 [2, 3].

Hyperammonemic Encephalopathy: A Complication of Gastric Bypass Surgery

Hyperammonemia is a metabolic abnormality characterized by elevated levels of ammonia in the blood. This case report illustrates a 72-year-old Caucasian female with a history of prior gastric bypass surgery done 15 years ago, who was admitted multiple times for acute encephalopathy over the course of a few months. The patient was found to have a gastro-gastric fistula seen on a CT scan of the abdomen, which was the culprit of her acute encephalopathy. The patient underwent fistula closure via esophagogastroduodenoscopy.

Nonfatal Hyperammonemic Encephalopathy as a Late Complication of Roux-en-Y Gastric Bypass

Roux-en-Y gastric bypass (RYGB) is the most common weight loss procedure performed in the US. Gastric bypass–related hyperammonemia (GaBHA) is a potentially fatal entity, characterized by encephalopathy associated with hyperammonemia and various nutritional deficiencies, which can present at variable time intervals after RYGB. Twenty-five cases of hyperammonemic encephalopathy after bariatric surgery have been previously reported in the literature. We describe the case of a 48-year-old Hispanic woman with no prior history of liver disease, presenting with nonfatal hyperammonemic encephalopathy as a late postoperative complication 20 years after undergoing a RYGB. Hyperammonemic encephalopathy in the absence of known hepatic dysfunction presents a diagnostic dilemma. An early diagnosis and intervention are crucial to decrease morbidity and mortality.

Postbariatric Surgery Hyperammonemia: A Rare Cause of Encephalopathy

Hyperammonemic encephalopathy is an under-recognized and potentially fatal complication of Roux-en-Y gastric bypass surgery. We present a case of a 42-year-old woman with no known history of liver disease who experienced worsening encephalopathy 1 year after bariatric surgery. She presented with elevated ammonia and severe encephalopathy requiring intubation. A complete workup led to the diagnosis of a urea cycle disorder. The patient was managed with lactulose, ammonia scavenging agents, and nutritional supplementation with a favorable outcome. We report this case to increase awareness of this condition and urge providers to maintain a high clinical suspicion in the appropriate setting.

Bariatric Surgery Causing Hyperammonemia

Bariatric surgery is recognized as a highly effective therapy for obesity but it does carry a risk of short term and long term complications since it results in a permanent alteration of the patient's anatomy. We present a case of 45-year-old female presented with a macular rash on extremities and facial rash from a rehabilitation center after having been discharged a month earlier from a revision surgery on her gastric bypass for anastomotic bleeding. She progressively became lethargic with Magnetic Resonance Imaging (MRI) of the brain showed symmetrically restricted diffusion concerning for hypoxic injury. Her ammonia levels were at 142 micromoles per liter (mmol/L) at the initial check which worsened to 432 mmol/L over a few days, despite treatment. Laboratory investigation later revealed her to be deficient in zinc along with many essential and nonessential amino acids. Supplemental nutrition was initiated, specifically fortifying her parenteral feeds with the essential amino acid combinations that were found deficient on testing. This lead to a slow but progressive improvement in encephalopathy. This case highlights the importance of understanding the short and long term complications of bariatric surgery. Although neurological complications are rare with peripheral neuropathy being the most common one, hyperammonemic encephalopathy is a very severe complication, with incompletely understood mechanisms and predispositions, frequently resulting in failure of recognition and subsequent delays in intervention.

Features of Adult Hyperammonemia Not Due to Liver Failure in the ICU

OBJECTIVES

To evaluate the epidemiology of hyperammonemia unrelated to liver failure in the critical care setting.

DESIGN

Retrospective case series.

SETTING

Critically ill patients admitted to ICUs at Mayo Clinic, Rochester, MN (medical ICU, two mixed medical-surgical ICUs, coronary care unit, or the cardiosurgical ICU) between July 1, 2004, and October 31, 2015.

PATIENTS

Adult critically ill patients with hyperammonemia not related to acute or chronic liver failure. We excluded patients with diagnosis of moderate or severe liver disease, hyperbilirubinemia, and patients who denied the use of their medical records.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 3,908 ICU patients with hyperammonemia, 167 (4.5%) had no evidence of acute or chronic liver failure. One-hundred one patients (60.5%) were male with median age of 65.7 years (interquartile range, 50-74.5 yr) and median serum ammonia level of 68 µg/dL (interquartile range, 58-87 µg/dL). Acute encephalopathy was present in 119 patients (71%). Predisposing conditions included malnutrition 27 (16%), gastric bypass six (3.6%), total parenteral nutrition four (2.4%); exposure to valproic acid 17 (10%); status epilepticus 11 (6.6%), high tumour burden 19 (11.3%), and renal failure 82 (49.1%). Urea cycle defects were diagnosed in seven patients (4.1%). Hospital mortality was high (30%), and median ammonia level was higher among the nonsurvivors (74 vs 67 µg/dL; p = 0.05). Deaths were more likely in hyperammonemic patients who were older (p = 0.016), had greater illness severity (higher Acute Physiology and Chronic Health Evaluation III score, p < 0.01), malignancy (p < 0.01), and solid organ transplantation (p = 0.04), whereas seizure disorder was more common in survivors (p = 0.02). After adjustment, serum ammonia level was not associated with increased mortality.

CONCLUSIONS

Hyperammonemia occurs in a substantial minority of critically ill patients without liver failure. These patients have a poor prognosis, although ammonia level per se is not independently associated with mortality. Serum ammonia should be measured when risk factors are present, such as nutritional deficiencies and protein refeeding, treatment with valproic acid, high tumour burden, and known or suspected urea cycle abnormalities.

An overview of complications affecting the Central Nervous System following bariatric surgery

Bariatric surgery has been considered as an effective treatment for morbid obesity. Apart from procedures related complications, a broad spectrum of neurological disorders affecting any part of neuraxis has been reported following BS. Central nervous system complications, although less common than peripheral nervous system complications, carry significant morbidity and potential mortality. Encephalopathy, behavioral and psychiatric disorders, myelopathy and optic neuropathy are the most frequently reported CNS complications. Early detection and prompt management may improve or completely reverse these neurological complications. It is essential that the treating physicians must be aware of their clinical manifestations and management, so early diagnosis and treatment can prevent patients from suffering significant neurological deficits and even death. This review discusses the clinical manifestations of these complications in detail which will help concerned physician in earlier recognition and hence prevent the delay in specific treatment.

Simultaneous living donor liver transplant with sleeve gastrectomy for metabolic syndrome and NASH-related ESLD-First report from India

Nonalcoholic steatohepatitis (NASH) with morbid obesity and metabolic syndrome is now a common cause of end-stage liver disease (ESLD). These patients are high-risk candidates for liver transplant, and require bariatric surgery to prevent recurrent disease in the new liver. Data reports bariatric surgery after transplant, which maybe difficult because of adhesions between the stomach and liver in living donor liver transplant (LDLT) recipient. We report the first case of combined LDLT with sleeve gastrectomy (SG) from India. A morbidly obese diabetic woman with NASH-related ESLD was planned for combined right lobe LDLT with open SG, in view of failed diet therapy, musculo-skeletal complaints, and restricted mobility. Postoperatively, with liver graft functioning adequately, bariatric diet restrictions resulted in maximum reduction of 25% weight, achieving a target BMI below 30 kg/m² within 2 months, along with complete cure of diabetes and better ambulation. Thus, combination of LDLT and bariatric surgery in the same sitting is safe and effective in management of metabolic syndrome and associated NASH-related ESLD.

Brain MRS glutamine as a biomarker to guide therapy of hyperammonemic coma

Acute idiopathic hyperammonemia in an adult patient is a life-threatening condition often resulting in a rapid progression to irreversible cerebral edema and death. While ammonia-scavenging therapies lower blood ammonia levels, in comparison, clearance of waste nitrogen from the brain may be delayed. Therefore, we used magnetic resonance spectroscopy (MRS) to monitor cerebral glutamine levels, the major reservoir of ammonia, in a gastric bypass patient with hyperammonemic coma undergoing therapy with N-carbamoyl glutamate and the ammonia-scavenging agents, sodium phenylacetate and sodium benzoate. Improvement in mental status mirrored brain glutamine levels, as coma persisted for 48h after plasma ammonia normalized. We hypothesize that the slower clearance for brain glutamine levels accounts for the delay in improvement following initiation of treatment in cases of chronic hyperammonemia. We propose MRS to monitor brain glutamine as a noninvasive approach to be utilized for diagnostic and therapeutic monitoring purposes in adult patients presenting with idiopathic hyperammonemia.

The nature of early astroglial protection-Fast activation and signaling

Our present review is focusing on the uniqueness of balanced astroglial signaling. The balance of excitatory and inhibitory signaling within the CNS is mainly determined by sharp synaptic transients of excitatory glutamate (Glu) and inhibitory γ-aminobutyrate (GABA) acting on the sub-second timescale. Astroglia is involved in excitatory chemical transmission by taking up i) Glu through neurotransmitter-sodium transporters, ii) K⁺ released due to presynaptic action potential generation, and iii) water keeping osmotic pressure. Glu uptake-coupled Na⁺ influx may either ignite long-range astroglial Ca²⁺ transients or locally counteract over-excitation via astroglial GABA release and increased tonic inhibition. Imbalance of excitatory and inhibitory drives is associated with a number of disease conditions, including prevalent traumatic and ischaemic injuries or the emergence of epilepsy. Therefore, when addressing the potential of early therapeutic intervention, astroglial signaling functions combating progress of Glu excitotoxicity is of critical importance. We suggest, that excitotoxicity is linked primarily to over-excitation induced by the impairment of astroglial Glu uptake and/or GABA release. Within this framework, we discuss the acute alterations of Glu-cycling and metabolism and conjecture the therapeutic promise of regulation. We also confer the role played by key carrier proteins and enzymes as well as their interplay at the molecular, cellular, and organ levels. Moreover, based on our former studies, we offer potential prospect on the emerging theme of astroglial succinate sensing in course of Glu excitotoxicity.

Combined liver transplantation and sleeve gastrectomy for end-stage liver disease in a bariatric patient: First European case-report

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Non-alcoholic Steatohepatitis is the 3rd indication for liver transplantation.

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Obese transplanted patients have higher morbidity and mortality rates.

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Bariatric surgery decreases morbidity and mortality in obese patients.

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Combined liver transplant and sleeve gastrectomy can be safely performed.

Introduction

Obesity is a contributor to the global burden of chronic diseases, including non-alcoholic fatty liver disease and non-alcoholic steatohepatitis (NASH). NASH cirrhosis is becoming a leading indication for liver transplant (LT). Obese transplanted patients have higher morbidity and mortality rates. One strategy, to improve the outcomes in these patients, includes bariatric surgery at the time of LT. Herein we report the first European combined LT and sleeve gastrectomy (SG).

Case presentation

A 53 years old woman with Hepatocellular carcinoma and Hepatitis C virus related cirrhosis, was referred to our unit. She also presented with severe morbid obesity (BMI 40 kg/m²) and insulin-dependent diabetes. Once listed for LT, she was assessed by the bariatric surgery team to undergo a combined LT/SG. At the time of transplantation the patient had a model for end-stage liver disease calculated score of 14 and a BMI of 38 kg/m².

The LT was performed using a deceased donor. An experienced bariatric surgeon, following completion of the LT, performed the SG. Operation time was 8 h and 50 min. The patient had an uneventful recovery and is currently alive, 5 months after the combined procedure, with normal allograft function, significant weight loss (BMI = 29 kg/m²), and diabetes resolution.

Conclusion

Despite the ideal approach to the management of the obese LT patients remains unknown, we strongly support the combined procedure during LT in selected patients, offering advantages in terms of allograft and patient survival, maintenance of weigh loss that will ultimately reduce obese related co-morbidities.