Clinical and biochemical aspects of thiamine treatment for metabolic acidosis during total parenteral nutrition

Clinical Characteristics and Outcomes Associated With High-Dose Intravenous Thiamine Administration in Patients With Encephalopathy

BACKGROUND

Wernicke encephalopathy is a common neuropsychiatric syndrome due to thiamine deficiency. There is no consensus regarding thiamine dosing when Wernicke encephalopathy is suspected. A longstanding dosing strategy for Wernicke encephalopathy is 100mg daily, yet updated clinical guidelines suggest using high-dose intravenous (HDIV) thiamine.

OBJECTIVE

To describe thiamine prescribing practices at a large, public academic hospital and investigate clinical characteristics and outcomes associated with HDIV thiamine in patients with encephalopathy who received IV thiamine.

METHODS

Electronic medical records of hospitalized patients who received thiamine between 4/4/2014 and 11/1/2015 were reviewed. Chi-square tests, Wilcoxon Rank Sum tests, and logistic regression were used to compare clinical variables in patients with encephalopathy who received HDIV thiamine (≥ 200mg twice daily) vs lower doses of IV thiamine.

RESULTS

Among the total of 5236 thiamine orders, 29% (n = 1531) were IV; 10% (n = 150) of IV orders met HDIV criteria. In patients with encephalopathy who received IV thiamine (n = 432), HDIV thiamine was administered to 20% (n = 86) and only 2.1% (n = 9) received dosing consistent with Royal College of Physicians guidelines. In bivariable analyses, HDIV thiamine was associated with surgical services (p = 0.001), psychiatric consultation (p < 0.001), and decreased mortality (p = 0.004). In multivariable models, the association between HDIV thiamine and decreased in-hospital mortality did not meet statistical significance (p = 0.061).

CONCLUSIONS

In a large, public academic hospital, guideline-concordant thiamine supplementation is rare and HDIV thiamine is infrequently prescribed to patients with encephalopathy. Further studies are needed to confirm the possible benefits of HDIV thiamine for patients with suspected thiamine-deficient encephalopathy.

Thiamin in Clinical Practice

Thiamin is a water-soluble vitamin also known as vitamin B1. Its biologically active form, thiamin pyrophosphate (TPP), is a cofactor in macronutrient metabolism. In addition to its coenzyme roles, TPP plays a role in nerve structure and function as well as brain metabolism. Signs and symptoms of thiamin deficiency (TD) include lactic acidosis, peripheral neuropathy, ataxia, and ocular changes (eg, nystagmus). More advanced symptoms include confabulation and memory loss and/or psychosis, resulting in Wernicke's encephalopathy and/or Wernicke's Korsakoff syndrome, respectively. The nutrition support clinician should be aware of patients who may be at risk for TD. Risk factors include those patients with malnutrition due to 1 or more nutrition-related etiologies: decreased nutrient intake, increased nutrient losses, or impaired nutrient absorption. Clinical scenarios such as unexplained heart failure or lactic acidosis, renal failure with dialysis, alcoholism, starvation, hyperemesis gravidarum, or bariatric surgery may increase the risk for TD. Patients who are critically ill and require nutrition support may also be at risk for TD, especially those who are given intravenous dextrose void of thiamin repletion. Furthermore, understanding thiamin's role as a potential therapeutic agent for diabetes, some inborn errors of metabolism, and neurodegenerative diseases warrants further research. This tutorial describes the absorption, digestion, and metabolism of thiamin. Issues pertaining to thiamin in clinical practice will be described, and evidence-based practice suggestions for the prevention and treatment of TD will be discussed.

Severe lactic acidosis and multiorgan failure due to thiamine deficiency during total parenteral nutrition

A 16-year-old perioperative paediatric patient presented with refractory lactic acidosis and multiorgan failure due to thiamine-deficient total parenteral nutrition during a recent national multivitamin shortage. Urgent empiric administration of intravenous thiamine resulted in prompt recovery from this life-threatening condition. Despite readily available treatment, a high index of suspicion is required to prevent cardiovascular collapse and mortality.

Wernicke's Encephalopathy After Longterm Feeding with Parenteral Nutrition

Wernicke's encephalopathy occurs due to thiamine (vitamin B1) deficiency which is characterized by occulomotor dysfunction, confusion and ataxia. Although it is most common with alcoholism, can also be seen due to hyperemesis caused by chemotherapy, Crohn's disease, gastrointestinal system surgery, AIDS, bariatric surgery and longterm feeding with parenteral nutrition. In this case, a 51-year-old woman who was treated with longterm total parenteral nutrition due to hyperemesis and had the diagnosis of Wernicke's encephalopathy after admission to the intensive care unit is presented.

Potential non-hypoxic/ischemic causes of increased cerebral interstitial fluid lactate/pyruvate ratio: a review of available literature

Microdialysis, an in vivo technique that permits collection and analysis of small molecular weight substances from the interstitial space, was developed more than 30 years ago and introduced into the clinical neurosciences in the 1990s. Today cerebral microdialysis is an established, commercially available clinical tool that is focused primarily on markers of cerebral energy metabolism (glucose, lactate, and pyruvate) and cell damage (glycerol), and neurotransmitters (glutamate). Although the brain comprises only 2% of body weight, it consumes 20% of total body energy. Consequently, the ability to monitor cerebral metabolism can provide significant insights during clinical care. Measurements of lactate, pyruvate, and glucose give information about the comparative contributions of aerobic and anaerobic metabolisms to brain energy. The lactate/pyruvate ratio reflects cytoplasmic redox state and thus provides information about tissue oxygenation. An elevated lactate pyruvate ratio (>40) frequently is interpreted as a sign of cerebral hypoxia or ischemia. However, several other factors may contribute to an elevated LPR. This article reviews potential non-hypoxic/ischemic causes of an increased LPR.

Detection of Cerebral Compromise With Multimodality Monitoring in Patients With Subarachnoid Hemorrhage

BACKGROUND:

Studies in traumatic brain injury suggest that monitoring techniques such as brain tissue oxygen (Pbto2) and cerebral microdialysis may complement conventional intracranial pressure (ICP) and cerebral perfusion pressure (CPP) measurements.

OBJECTIVE:

In this study of poor-grade (Hunt and Hess grade IV and V) subarachnoid hemorrhage (SAH) patients, we examined the prevalence of brain hypoxia and brain energy dysfunction in the presence of normal and abnormal ICP and CPP.

METHODS:

SAH patients who underwent multimodal neuromonitoring and cerebral microdialysis were studied. We examined the frequency of brain hypoxia and energy dysfunction in different ICP and CPP ranges and the relationship between Pbto2 and the lactate/pyruvate ratio (LPR).

RESULTS:

A total of 2394 samples from 19 patients were analyzed. There were 149 samples with severe brain hypoxia (Pbto2 ≤10 mm Hg) and 347 samples with brain energy dysfunction (LPR &gt;40). The sensitivities of abnormal ICP or CPP for elevated LPR and reduced Pbto2 were poor (21.2% at best), and the LPR or Pbto2 was abnormal in many instances when ICP or CPP was normal. Severe brain hypoxia was often associated with an LPR greater than 40 (86% of samples). In contrast, mild brain hypoxia (≤20 mm Hg) and severe brain hypoxia were observed in only 53% and 36% of samples with brain energy dysfunction, respectively.

CONCLUSION:

Our data demonstrate that ICP and CPP monitoring may not always detect episodes of cerebral compromise in SAH patients. Our data suggest that several complementary monitors may be needed to optimize the care of poor-grade SAH patients.

A rare case of severe lactic acidosis in a preterm infant: lack of thiamine during total parenteral nutrition

Total parenteral nutrition (TPN) is a revolution in neonatal intensive care unit (NICU) care, but this therapy is not without problems. A 35-week-old, 1300 g female infant was transferred to our NICU because of bilious vomiting and feeding problems. When enteral feeding was started again, a severe condition similar to the previous one developed. On the 24th day, the patient underwent surgery with a diagnosis of Hirschprung's disease. One week before surgery, the parenteral solutions were composed without vitamins because intravenous vitamin supplements suitable for infants were not available. Thereafter, the patient suffered from severe hypoglycaemia, and sepsis started to develop, accompanied by a large anion gap and metabolic acidosis which is severe lactic acidosis refractory to massive doses of bicarbonate. The acidosis improved significantly when the patient was treated with thiamin. Although TPN is life saving in the NICU, meticulous attention must be paid while treating a patient with TPN, and all possible nutrients should be provided. In this report, a case of a preterm newborn requiring a prolonged period of TPN and complicated by serious lactic acidosis is presented and discussed.

Refeeding syndrome: treatment considerations based on collective analysis of literature case reports

Refeeding syndrome (RFS) represents a group of clinical findings that occur in severely malnourished individuals undergoing nutritional support. Cardiac arrhythmias, multisystem organ dysfunction, and death are the most severe symptoms observed. As the cachectic body attempts to reverse its adaptation to the starved state in response to the nutritional load, symptoms result from fluid and electrolyte imbalances, with hypophosphatemia playing a central role. Because guidelines for feeding the malnourished patient at risk for refeeding syndrome is scarce, we have provided management recommendations based on the knowledge derived from a collection of reported English literature cases of the RFS. A MEDLINE search using keywords including "refeeding syndrome," "RFS," and "refeeding hypophosphatemia" was performed. References from initial cases were utilized for more literature on the subject. We have emphasized the continued importance of managing patients at risk for RFS, compared how management of the severely malnourished patients have evolved over time, and provided comprehensive clinical guidelines based on the sum of experience documented in the case reports for the purpose of supplementing the guidelines available. Based on our review, the most effective means of preventing or treating RFS were the following: recognizing the patients at risk; providing adequate electrolyte, vitamin, and micronutrient supplementation; careful fluid resuscitation; cautious and gradual energy restoration; and monitoring of critical laboratory indices.

Coronary artery bypass graft surgery depletes plasma thiamine levels

OBJECTIVE

Thiamine is an essential component of cellular metabolism, and lack of this vitamin results in a potentially life-threatening biochemical lesion. The stress of surgery and critical disease depletes electrolytes, minerals, and essential biochemical substrates. We hypothesized that critical illness (represented by major surgery) would result in decreased thiamine levels over time.

METHODS

We performed a prospective, observational study of serial thiamine levels of 15 patients who underwent non-emergent coronary artery bypass graft surgery. The primary endpoint was change in thiamine levels from before to immediately after surgery. Secondary endpoints included change in thiamine levels from presurgical to 6- and 24-h time points.

RESULTS

Of the 15 study patients, 1 did not have a plasma thiamine measurement at time 0 because of laboratory error and could not be accounted for in paired comparisons over time. Plasma thiamine levels decreased significantly from before to after coronary artery bypass grafting (P=0.0004). In addition, there was a statistically significant decrease in thiamine levels from before surgery to 24h (P=0.003).

CONCLUSION

Our data suggest that major surgery (as a surrogate for the stress of critical illness) depletes thiamine levels; further study is needed to determine whether routine replacement of thiamine in the critically ill is warranted.

Clinical examination of the water-soluble vitamin levels in blood during peripheral parenteral nutrition

The water-soluble vitamin (included vitamin B1, B6, B12 and C) preparations are not always replenished when peripheral parenteral nutrition (PPN) is used in Japan. We evaluated the need for administration of vitamins preparation during PPN, and involved analysis of the blood levels of water-soluble vitamins in patients receiving perioperative PPN before and after gastrectomy. Patients were examined as two set of groups as follows; 18 patients who did not receive water-soluble vitamin preparations during PPN, the Unsupplemented Group, and 22 patients who received such preparations during PPN, the Supplemented Group. Consequently, in the Unsupplemented Group, the blood vitamin B1 level during the early postoperative period was significantly lower than the preoperative level, but in the Supplemented Group, it was significantly higher than the preoperative level. In the Supplemented Group, the blood vitamin B12 level during the early postoperative period was markedly higher than the preoperative level. And in both groups, the blood vitamin C level remained below the lower limit of the criterion range throughout the perioperative period. These results suggested that administration of water-soluble vitamins during PPN was needed to avoid potential vitamin deficiencies after surgery and to prevent a potential onset of severe metabolic complications from any deficiencies.

Ketosis and cardiac failure: common signs of a single condition

The metabolic effects of chronic alcohol abuse can induce a broad spectrum of disorders. We describe the case of an initially unidentified alcoholic, poorly nourished woman who presented with ketoacidosis. She developed severe cardiac failure, which did not respond to classical treatment. The administration of intravenous thiamine resulted in an impressive recovery of cardiac function. Laboratory examinations confirmed the diagnosis of alcoholic ketoacidosis and cardiac beriberi. The clinical entity and treatment of these two uncommon disorders are discussed. If recognized early both diseases (and their combination) are fully reversible.

Severe lactic acidosis due to thiamine deficiency in a patient with B-cell leukemia/lymphoma on total parenteral nutrition during high-dose methotrexate therapy

An 11-month-old girl with B-cell leukemia/lymphoma developed profound lethargy due to severe lactic acidosis during chemotherapy and total parenteral nutrition (TPN). Initial treatment with NaHCO3 was ineffective. Treatment with a vitamin cocktail (OH-cobalamin, pyridoxine, thiamine, riboflavine, biotin, carnitine) at pharmacologic doses rapidly improved the child's clinical and laboratory status. Lactic acidosis was caused by an impairment of pyruvate dehydrogenase complex, which was due to lack of its necessary cofactor thiamine in the TPN. This case report indicates that lactic acidosis may be a front-line diagnosis in patients on TPN with lethargy and outlines the need for monitoring thiamine supply in TPN.

Severe metabolic acidosis and heart failure due to thiamine deficiency

We report the case of a male patient with severe metabolic acidosis and heart failure caused by thiamine deficiency. He was admitted in August 1998 to the Tokai University Oiso Hospital because of severe dyspnea. The patient was diagnosed with heart failure and metabolic acidosis of unknown causes based on arterial blood gas analysis, chest x ray, and ultrasonic echocardiographic examinations. Our previous experience in treating a patient with thiamine deficiency caused by total parenteral nutrition without thiamine supplementation suggested that this patient was deficient in thiamine. The serum thiamine level was low and the lactate level was high. After intravenous administration of thiamine, the acidosis and heart failure disappeared. Dietary analysis showed that thiamine intake was low (0.32 mg/1000 kcal/d). Thiamine deficiency should be included in the differential diagnosis when encountering cases of heart failure with severe metabolic acidosis, even in developed countries.

[Is thiamine supplementation necessary in patient with cardiac insufficiency?]

Interest has recently risen regarding thiamine deficiency in patients with cardiac deficiency who are receiving long-term diuretic therapy. Thiamine deficiency can lead biventricular myocardial failure (cardiac beriberi), and treatment consists of thiamine administration. Studies have shown that long-term furosemide use may be associated with thiamine deficiency through urinary loss, contributing to cardiac insufficiency in patients with congestive heart failure. Thiamine supplementation could improved left ventricular function. However, the results of those studies are controversial, and none study have till proved the clinical impact of a systematic administration of thiamine in a cohort of patients with cardiac insufficiency. To date, and waiting for available literature, thiamine administration should be consider in patients at risk for thiamine deficiency (elderly, malnourished, alcoholic), and in patients receiving very large doses of diuretics.

Determination of thiamine by high-performance liquid chromatography

High-performance liquid chromatographic methods for the determination of thiamine (vitamin B1) in foodstuffs or biological tissues and fluids are outlined and discussed. The methods are often similar and interchangeable, sample extraction and clean up procedures being the major difference. Most of the methods use either ultraviolet or fluorescence detection. Fluorescence detection requires either precolumn or postcolumn oxidation of thiamine to thiochrome. A number of methods are recommended and problems with standardization are emphasized.

[Severe lactic acidosis and thiamine deficiency during parenteral nutrition in a child]

We report the case of a leukemic child treated with chemotherapy and parenteral nutrition for three weeks, who developed a severe lactic acidosis. Clinical features included both digestive and neurological disorders associated with a moderate cardiovascular collapse. After elimination of a toxic, a neoplastic or a septic cause, a thiamin (or vitamin B1) deficiency was suspected because of the lack of vitamin supply to parenteral nutrition. Intravenous administration of thiamin rapidly controlled lactic and clinical features. The diagnosis was confirmed by a low plasmatic concentration of thiamin. Thiamin deficiency must be suspected in case of severe lactic acidosis during parenteral nutrition and systematically prevented by supply of vitamins.

Thiamine-Responsive Lactic Acidosis, Encephalopathy, and Shock

Objective:

To report a case of severe lactic acidosis, encephalopathy, and hypotension in a patient receiving total parenteral nutrition without multivitamin supplementation and the dramatic response to intravenous administration of thiamine.

Case Summary:

A 15-year-old African-American girl undergoing treatment for chronic myelogenous leukemia with allogenic bone marrow transplantation and requiring total parenteral nutrition was admitted to our intensive care unit for management of life-threatening lactic acidosis, encephalopathy, and hemodynamic instability. Because of the manufacturing shortage of parenteral multivitamin preparations, oral multivitamins were prescribed; however, the patient was unable to swallow the oral multivitamins because of oral mucositis. Intravenous administration of thiamine promptly reversed the profound metabolic, neurologic, and hemodynamic abnormalities.

Discussion:

Carbohydrate loading associated with inadequate thiamine intake may result in potentially lethal metabolic, neurologic, and hemodynamic alterations. Prompt intravenous administration of thiamine can rapidly reverse metabolic acidosis, encephalopathy, and shock in such situations.

Conclusions:

Adequate administration of multivitamins must be ensured in all patients receiving total parenteral nutrition.