Factors contributing to the development of hypophosphataemia when refeeding using parenteral nutrition

Risk factors for the development of refeeding syndrome in adults: A systematic review

Identifying patients with a particularly high risk of refeeding syndrome (RFS) is essential for taking preventive measures. To guide the development of clinical decision-making and risk prediction models or other screening tools for RFS, increased knowledge of risk factors is needed. Therefore, we conducted a systematic review to identify risk factors for the development of RFS. PubMed, EMBASE, Cochrane Library, and Web of Science were searched from January 1990 until March 2023. Studies investigating demographic, clinical, drug use, laboratory, and/or nutrition factors for RFS were considered. The Newcastle-Ottawa Scale was used to appraise the methodological quality of included studies. Of 1589 identified records, 30 studies were included. Thirty-three factors associated with increased risk of RFS after multivariable adjustments were identified. The following factors were reported by two or more studies, with 0-1 study reporting null findings: a previous history of alcohol misuse, cancer, comorbid hypertension, high Acute Physiology and Chronic Health Evaluation II score, high Sequential Organ Failure Assessment score, low Glasgow coma scale score, the use of diuretics before refeeding, low baseline serum prealbumin level, high baseline level of creatinine, and enteral nutrition. The majority of the studies (20, 66.7%) were of high methodological quality. In conclusion, this systematic review informs on several risk factors for RFS in patients. To improve risk stratification and guide development of risk prediction models or other screening tools, further confirmation is needed because there were a small number of studies and a low number of high-quality studies on each factor.

Association between energy delivery from parenteral nutrition and refeeding syndrome in hospitalized adults: A retrospective cohort study

BACKGROUND

Patients receiving parenteral nutrition (PN) may develop refeeding syndrome (RFS). This study determined RFS prevalence in hospitalized adults on PN and evaluated whether higher energy delivered by PN on day 1 of PN initiation was associated with RFS development.

METHODS

We reviewed the medical records of adult patients receiving PN at a Thai quaternary hospital from June 2019 to May 2022. RFS was defined based on the Nutrition Management Clinical Practice Recommendation by the Society of Parenteral and Enteral Nutrition of Thailand. The association between PN energy delivery and RFS development was determined using a generalized estimating equation for multiple logistic regression analysis adjusted for NICE guideline risk factors.

RESULTS

A total of 547 patients was included (mean age 59.8 ± 17.2 years, mean body mass index 20.7 ± 4.8 ). The prevalence of RFS was 45%. Factors associated with RFS included energy from PN on the first day of PN initiation (adjusted odds ratio [aOR] 1.17; 95% CI 1.04-1.33; for every 5 kcal/kg/day increase), starvation >5 days prior to PN (aOR 1.54; 95% CI 1.04-2.26), concomitant diuretic use (aOR 1.81; 95% CI 1.25-2.64), low baseline potassium level (aOR 1.79; 95% CI 1.19-2.70), and individual compounding PN (aOR 1.61; 95% CI 1.04-2.51).

CONCLUSION

RFS was common among hospitalized patients receiving PN. The amount of energy delivered on the first day of PN was independently associated with RFS, raising a concern regarding initiation of PN with higher energy.

Parenteral Nutrition in the Pediatric Oncologic Population: Are There Any Sex Differences?

Gender-based medicine is attracting increasing interest every day, but studies on pediatric populations are still limited. In this setting, sex differences among patients undergoing total parenteral nutrition (TPN) have not been previously reported. This study investigated the presence of sex differences in parenteral nutrition composition and outcomes among a cohort of pediatric patients admitted at the Oncohematology and Bone Marrow Transplant Unit of the Institute for Maternal and Child Health "Burlo Garofolo" of Trieste, Italy. For all 145 recruited patients (87 males, 58 females), the following data were collected: age, sex, volume and duration of TPN, macro- and micronutrient composition of TPN bags, electrolytic or blood gases imbalance, glycolipid alterations, liver damage during TPN, and the incidence of sepsis and thrombosis. The analysis showed that females required higher daily phosphate intake (p = 0.054) and essential amino acid supplementation (p = 0.07), while males had a higher incidence of hypertriglyceridemia (p < 0.05) and cholestasis. A higher incidence of sepsis was found in the non-transplanted male population (p < 0.05). No significant differences were appreciable in other analyzed variables. This study aims to create a basis for future gender-based nutritional recommendations in the pediatric field.

Hypophosphatemia in cancer patients

Dysregulation of phosphorus homeostasis resulting in hypophosphatemia is common in cancer patients and can result in serious complications and impact outcomes. Several factors, including critical illness, nutritional status, cancer type and therapy, influence the development of hypophosphatemia. Hypophosphatemia can develop as a result of phosphaturic mesenchymal tumors or as a paraneoplastic phenomenon. The clinical presentation for hypophosphatemia varies depending on the duration and severity of the hypophosphatemia and affects several organ systems. Among other serious effects, hypophosphatemia can impair tissue oxygenation and can cause hemolysis, leukocyte and platelet dysfunction, encephalopathy, seizures, arrhythmias, cardiomyopathy, rhabdomyolysis and coma. Multiple studies have demonstrated that hypophosphatemia is an adverse prognostic marker in inpatients with increased in-hospital stay, mortality and postoperative complications. The phosphate level is homeostatically regulated and maintained in a narrow range by three main hormones: parathyroid hormone, fibroblast growth factor 23 and 1,25-dihydroxyvitaminD₃. Together, these hormones regulate how the intestine, kidneys and bones traffic phosphorus. Several hematological malignancies and cancer therapies are associated with proximal tubular dysfunction (Fanconi syndrome), resulting in phosphaturia. Caution should be taken with parenteral administration of phosphate salts, because secondary complications can develop, principally due to hypocalcemia. The general approach to hypophosphatemia should target the underlying cause. Early recognition and prevention are essential and the approach to hypophosphatemia in the cancer patient, because of the nuances and complexity, should be multidisciplinary.

The Refeeding Syndrome: a neglected but potentially serious condition for inpatients. A narrative review

The Refeeding Syndrome (RFS) is a potentially serious, but still overlooked condition, occurring in individuals who are rapidly fed after a period of severe undernourishment. RFS derives from an abnormal electrolyte and fluid shifts leading to many organ dysfunctions. Symptoms generally appear within 2-5 days of re-feeding and may be absent/mild or severe and life threating, depending on the pre-existing degree of malnutrition and comorbidities. The lack of a standard definition and the nonspecificity of the symptoms make both incidence estimate and diagnosis difficult. In 2020, the American Society for Parenteral and Enteral Nutrition (ASPEN) proposed a unifying definition for the RFS and its severity classification. The awareness of the condition is crucial for identifying patients at risk, preventing its occurrence, and improving the management. The objectives of this narrative review were to summarize the current knowledge and recommendations about the RFS and to provide useful tips to help physicians to recognize and prevent the syndrome.

Hypophosphatemia in a Specialized Intestinal Failure Unit: An Observational Cohort Study

BACKGROUND

Patients with intestinal failure (IF) are prone to hypophosphatemia and shifts in magnesium and potassium levels. Although these shifts are often attributed to refeeding syndrome (RFS), the incidence of electrolyte shifts among patients with IF is unknown. We evaluated the occurrence of hypophosphatemia and other electrolyte shifts according to the functional and pathophysiological IF classifications.

METHODS

We consecutively included all patients' first admission to an IF unit from 2013 to 2017. Electrolyte shifts were defined as severe hypophosphatemia <0.6 mmol/L (mM) or any 2 other shifts below reference range, comprising hypomagnesemia <0.75 mM, hypophosphatemia <0.8 mM, or hypokalemia <3.5 mM. Outcomes included length of stay, central line-associated bloodstream infection, and other infections. Mortality was evaluated 6 months after discharge.

RESULTS

Of 236 patients with IF, electrolyte shifts occurred in 99 (42%), and 127 (54%) of these patients received intravenous supplementation with either phosphate, magnesium, or potassium. In patients who started parenteral nutrition, up to 62% of early-onset shifts (<5 days) related to refeeding, and up to 63% of late-onset shifts (≥5 days) could be ascribed to infections. Derangements occurred in 7 (18%) with type 1 IF, 53 (43%) with type 2 IF, and 39 (53%) readmitted patients with type 3 IF. Of 133 patients with IF secondary to short-bowel syndrome, 65 (49%) developed shifts.

CONCLUSION

In patients with IF, electrolyte shifts are frequent but not always due to RFS. Electrolyte shifts are common in patients with type 2 and those readmitted with type 3 IF.

Mortality associated with new risk classification of developing refeeding syndrome in critically ill patients: A cohort study

BACKGROUND & AIMS

Although refeeding syndrome (RFS) has been recognized as a potentially fatal metabolic complication, the definition of RFS has remained unclear. Recently, European researchers suggested an evidence-based and consensus-supported algorithm that consisted of a new RFS risk classification and treatment strategies for medical inpatients. The classification was based on the National Institute for Health and Clinical Excellence (NICE) criteria for patients at risk of developing RFS. In this study, we aimed to investigate the frequency of each applied new risk group and the association between the new classification and mortality in critically ill patients.

METHODS

This cohort study was conducted at a Japanese metropolitan tertiary-care university hospital from December 2016 to December 2018. We included critically ill adult patients who were admitted to the intensive care unit (ICU) via the emergency department and who stayed in the ICU for 24 h or longer. We applied the new risk classification based on the NICE RFS risk factors on ICU admission. The main exposure was risk classification of RFS: no risk, low risk, high risk, or very high risk. The primary outcome was in-hospital mortality censored at day 30 after ICU admission. We performed a multivariable analysis using Cox proportional hazard regression.

RESULTS

We analyzed 542 patients who met the eligibility criteria. The prevalence of the four RFS risk classification groups was 25.8% for no risk, 25.7% for low risk, 46.5% for high risk, and 2.0% for very high risk. The 30-day mortality was 5.0%, 7.2%, 16.3%, and 27.3%, respectively (log-rank trend test: p < 0.001). In the multivariable Cox regression, adjusted hazard ratios with no risk group as a reference were 1.28 (95% CI 0.48-3.38) for low risk, 2.81 (95% CI 1.24-6.35) for high risk, and 3.17 (95% CI 0.78-12.91) for very high risk.

CONCLUSIONS

Approximately half the critically ill patients were categorized as high or very high risk based on the new risk classification. Furthermore, as the risk categories progressed, the 30-day in-hospital mortality increased. Early recognition of patients at risk of developing RFS may improve patient outcomes through timely and optimal nutritional treatment.

Management of Refeeding Syndrome in Medical Inpatients

Refeeding syndrome (RFS) is the metabolic response to the switch from starvation to a fed state in the initial phase of nutritional therapy in patients who are severely malnourished or metabolically stressed due to severe illness. It is characterized by increased serum glucose, electrolyte disturbances (particularly hypophosphatemia, hypokalemia, and hypomagnesemia), vitamin depletion (especially vitamin B1 thiamine), fluid imbalance, and salt retention, with resulting impaired organ function and cardiac arrhythmias. The awareness of the medical and nursing staff is often too low in clinical practice, leading to under-diagnosis of this complication, which often has an unspecific clinical presentation. This review provides important insights into the RFS, practical recommendations for the management of RFS in the medical inpatient population (excluding eating disorders) based on consensus opinion and on current evidence from clinical studies, including risk stratification, prevention, diagnosis, and management and monitoring of nutritional and fluid therapy.

Refeeding syndrome in the frail elderly population: prevention, diagnosis and management

Aging is linked to physiological and pathophysiological changes. In this context, elderly patients often are frail, which strongly correlates with negative health outcomes and disability. Elderly patients are often malnourished, which again is an independent risk factor for both frailty and adverse clinical outcomes. Malnutrition and resulting frailty can be prevented by adequate nutritional interventions. Yet, use of nutritional therapy can also have negative consequences, including a potentially life-threatening metabolic alteration called refeeding syndrome (RFS) in high-risk patients. RFS is characterized by severe electrolyte shifts (mainly hypophosphatemia, hypomagnesemia and hypokalemia), vitamin deficiency (mainly thiamine), fluid overload and salt retention leading to organ dysfunction and cardiac arrhythmias. Although the awareness of malnutrition among elderly people is well established, the risk of RFS is often neglected, especially in the frail elderly population. This partly relates to the unspecific clinical presentation and laboratory changes in the geriatric population. The aim of this review is to summarize recently published recommendations for the management of RFS based on current evidence from clinical studies adapted with a focus on elderly patients.

Incidence and Risk Factors of Refeeding Syndrome in Head and Neck Cancer Patients-An Observational Study

This study aimed to determine the incidence rates of refeeding phenomena (defined as a decline in p-phosphate) and refeeding syndrome (RFS; defined as development of clinical symptoms in addition to a decline in p-phosphate) in head and neck cancer patients, and to identify risk factors. Fifty-four head and neck cancer patients referred for surgery were included. Forty-six potential risk factors were registered at the baseline, and p-phosphate was measured at Days 2, 4, and 7. Eleven patients (20%) developed RFS, and twenty-eight (52%) developed refeeding phenomena. At baseline, these patients presented a higher prevalence of head and neck pain, eating difficulties, higher p-phosphate levels, lower p-transferrin levels, and, in men, lower b-hemoglobin levels. Patients who developed symptoms had a decline in p-phosphate ≥0.22 mmol/l. At baseline, these patients had higher p-phosphate levels, higher alcohol consumption, and lower p-transferrin and p-sodium levels, as well as a higher prevalence of eating difficulties, low handgrip strength (HGS), and a history of radiation therapy. The risk factors most strongly associated with the development of refeeding phenomena and RFS were pain, eating difficulties, low HGS, high alcohol intake, and previous radiation therapy.

Refeeding hypophosphatemia in adolescents with anorexia nervosa: a systematic review

The rate of adolescents presenting with anorexia nervosa (AN) is increasing. Medically unstable adolescents are admitted to the hospital for nutrition restoration. A lack of global consensus on appropriate refeeding practices of malnourished patients has resulted in inconsistent refeeding practices. Refeeding hypophosphatemia (RH) is the most common complication associated with refeeding the malnourished patient. This review sought to identify the range of refeeding rates adopted globally and the implication that total energy intake and malnutrition may have on RH while refeeding adolescents with anorexia nervosa. Studies were identified by a systematic electronic search of medical databases from 1980 to September 2012. Seventeen publications were identified, including 6 chart reviews, 1 observational study, and 10 case reports, with a total of 1039 subjects. The average refeeding energy intake was 1186 kcal/d, ranging from 125-1900 kcal/d, with a mean percentage median body mass index (% mBMI) of 78%. The average incidence rate of RH was 14%. A significant correlation between malnutrition (% mBMI) and post-refeeding phosphate was identified (R (2) = 0.6, P = .01). This review highlights the disparity in refeeding rates adopted internationally in treating malnourished adolescents with anorexia nervosa. Based on this review, the severity of malnutrition seems to be a marker for the development of RH more so than total energy intake.

Leptin and insulin growth factor 1: diagnostic markers of the refeeding syndrome and mortality

Refeeding syndrome is difficult to diagnose since the guidelines for identifying those at risk are largely based on subjective clinical parameters and there are no predictive biochemical markers. We examined the suitability of insulin-like growth factor 1 (IGF1) and leptin as markers to identify patients at risk of the refeeding syndrome before initiation of parenteral nutrition (PN). A total of thirty-five consecutive patients referred for commencement of PN were included. Serum leptin and IGF1 were measured before starting PN. Electrolytes, liver and renal function tests were conducted before and daily for 1 week after initiating PN. The primary outcome was a decrease in phosphate 12–36 h after initiating PN. ‘Refeeding index’ (RI) was defined as leptin × IGF1 divided by 2800 to produce a ratio of 1·0 in patients who are well nourished. RI had better sensitivity (78 %; 95 % CI 40, 97 %) and specificity (78 %; 95 % CI 40, 97 %) with a likelihood ratio of 3·4, at a cut-off value of 0·19 for predicting a ≥ 30 % decrease in phosphate concentration within 12–36 h after starting PN, compared with IGF1 or leptin alone. However, IGF1 was a better predictor of mortality than either leptin or the RI. The present study is the first to derive and test the ‘RI’, and find that it is a sensitive and specific predictor of the refeeding syndrome in hospitalised patients before starting PN.