Incidence and Prevalence of Fibrous Dysplasia/McCune-Albright Syndrome: A Nationwide Registry-Based Study in Denmark.

CONTEXT: Fibrous dysplasia/McCune-Albright syndrome (FD/MAS) is a rare genetic disorder. Incidence and prevalence are not well-studied. Epidemiological research is complicated by the rarity of FD/MAS, absence of registries, heterogeneous presentation, and possibly asymptomatic phenotype. FD/MAS may present with FGF23-mediated hypophosphatemia, of which the epidemiology is also unclear. OBJECTIVE: Evaluate incidence and prevalence of FD/MAS and FD/MAS-related hypophosphatemia. METHODS: This cohort study based on the nationwide Danish National Patient Registry from 1995-2018, included patients identified by ICD-10 codes M85.0 (monostotic FD [MFD]) and Q78.1 (polyostotic FD [PFD]/MAS). Incidence rates and prevalence were calculated and stratified by sex, age, calendar period, and diagnosis code. Cases were screened for FD-associated hypophosphatemia by diagnosis code E.83 (disorder of mineral metabolism) and dispatched vitamin D analogues. RESULTS: A total of 408 patients were identified, 269 with MFD (66%), 139 with PFD/MAS (34%), comparable between sexes. Incidence of FD/MAS demonstrated increasing secular trend with a rate of 3.6 per 1 000 000 person-years (95% CI: 2.9, 4.5) in 2015-2018. Incidence peaked between age 11 and 20. Prevalence of FD/MAS increased over time to 61.0 (95% CI: 54.6, 67.4) per 1 000 000 persons in 2018. The incidence rate of MFD was 1.5-fold that of PFD/MAS in the first decade, rising to 2.5-fold in the last decade. No FD/MAS cases were registered with diagnosis code or treatment for hypophosphatemia. CONCLUSION: FD/MAS is rare, diagnosis peaks during adolescence without sex predominance, and MFD is most prevalent. Hypophosphatemia may be underdiagnosed and undertreated, or it may be underregistered, comparing this study to literature.

Prevalence of FGF23 elevation in patients with hypophosphatemia.

BACKGROUND AND AIMS: To investigate the contribution of FGF23 in explaining the cases of hypophosphatemia observed in clinical practice, we aimed to determine for the first time the prevalence of FGF23 elevation in patients with hypophosphatemia and to describe the different mechanisms of FGF23-related hypophosphatemic disorders. MATERIALS AND METHODS: We performed a prospective, observational, multicenter, cohort study of 260 patients with hypophosphatemia. Blood measurements (PTH, 1,25-dihydroxyvitamin D, bone alkaline phosphatase, 25-hydroxyvitamin D, and FGF23) were performed on a Liaison XL® (DiaSorin) analyzer. RESULTS: Primary elevation of FGF23 (>95.4 pg/mL) was reported in 10.4% (95CI: 7.0-14.7) of patients (n = 27) with hypophosphatemia, suggesting that at least 1 in 10 cases of hypophosphatemia was erroneously attributed to an etiology other than FGF23 elevation. Patients with elevated blood FGF23 were grouped according to the etiology of the FGF23 elevation. Thus, 10 patients had a renal pathology, chronic kidney disease or post-renal transplantation condition. The remaining patients (n = 17) had the following etiologies: malignancies (n = 9), benign pancreatic tumor (n = 1), post-cardiac surgery (n = 4), cirrhosis (n = 2), and chronic obstructive pulmonary disease (n = 1). CONCLUSION: In order to improve patient management, it seems essential to better integrate plasma FGF23 measurement into the routine evaluation of hypophosphatemia.

Disease Manifestations and Complications in Dutch X-Linked Hypophosphatemia Patients.

X-linked hypophosphatemia (XLH) is the most common monogenetic cause of chronic hypophosphatemia, characterized by rickets and osteomalacia. Disease manifestations and treatment of XLH patients in the Netherlands are currently unknown. Characteristics of XLH patients participating in the Dutch observational registry for genetic hypophosphatemia and acquired renal phosphate wasting were analyzed. Eighty XLH patients, including 29 children, were included. Genetic testing, performed in 78.8% of patients, showed a PHEX mutation in 96.8%. Median (range) Z-score for height was - 2.5 (- 5.5; 1.0) in adults and - 1.4 (- 3.7; 1.0) in children. Many patients were overweight or obese: 64.3% of adults and 37.0% of children. All children received XLH-related medication e.g., active vitamin D, phosphate supplementation or burosumab, while 8 adults used no medication. Lower age at start of XLH-related treatment was associated with higher height at inclusion. Hearing loss was reported in 6.9% of children and 31.4% of adults. Knee deformities were observed in 75.0% of all patients and osteoarthritis in 51.0% of adult patients. Nephrocalcinosis was observed in 62.1% of children and 33.3% of adults. Earlier start of XLH-related treatment was associated with higher risk of nephrocalcinosis and detection at younger age. Hyperparathyroidism longer than six months was reported in 37.9% of children and 35.3% of adults. This nationwide study confirms the high prevalence of adiposity, hearing loss, bone deformities, osteoarthritis, nephrocalcinosis and hyperparathyroidism in Dutch XLH patients. Early start of XLH-related treatment appears to be beneficial for longitudinal growth but may increase development of nephrocalcinosis.

Refeeding Hypophosphatemia in Oldest Old Critically Ill Patients.

BACKGROUND: Refeeding syndrome is characterized by metabolic and electrolyte alterations that result from the initiation of feeding after a period of inadequate caloric intake. Especially, in the elderly with acute and/or chronic illness, nutritional deficiencies are common, and diminished oral intake with effects of catabolic status yields malnutrition. This study was conducted to evaluate refeeding hypophosphatemia and its consequences on outcomes in the oldest old critically ill patients. METHODS: This study was designed as a retrospective cohort study that included patients who were 80 years old or older admitted to ICU. Patients were grouped depending on whether hypophosphatemia occurred after 48 hours of admission who started feeding. RESULTS: The median age of all patients was 87[82-90] years and 61(73%) of them were female. Refeeding hypophosphatemia was observed in 25(30%) patients. When patients were grouped depending on the occurrence of hypophosphatemia, groups were similar according to the severity scores, and comorbidities. Neither ICU mortality nor hospital mortality was different between groups (p=0.76 and p=0.19, respectively). CONCLUSION: Refeeding hypophosphatemia incidence was similar to previous studies, although study patients were the highest risk group. Outcome parameters including mortality rate and length of ICU stay were not different between patients with or without refeeding hypophosphatemia.

The impact of tubular dysfunction and its relationship with acute kidney injury in children.

BACKGROUND: Tubular dysfunction can cause electrolyte disturbances with potentially serious consequences. We studied the epidemiology and outcomes of electrolyte disturbances and tubular dysfunction among critically ill children and evaluated their relationships with acute kidney injury (AKI). METHODS: We conducted a prospective cohort study recruiting children aged 1 month to ≤ 18 years old admitted to the pediatric intensive care unit (PICU) from 6/2020 to 6/2021. The serum levels of sodium, potassium, calcium, phosphate, and magnesium were reviewed and simultaneous urinary investigations for tubular function were performed among children with electrolyte disturbances. RESULTS: Altogether there were 253 episodes of admission. The median (interquartile) age was 4.9 (1.3-11.0) years and 58.1% were male. The median number of electrolyte disorders was 3 (2-4) types. Hypophosphatemia (74.2%), hypocalcemia (70.3%) and hypermagnesemia (52.9%) were the three commonest types of disturbances. Urinary electrolyte wasting was commonly observed among children with hypomagnesemia (70.6%), hypophosphatemia (67.4%) and hypokalemia (28.6%). Tubular dysfunction was detected in 82.6% of patients and urinary ß2-microglobulin level significantly correlated with the severity of tubular dysfunction (p < 0.001). The development of tubular dysfunction was independent of AKI status. Tubular dysfunction was associated with mortality (p < 0.001) and was an independent predictor of PICU length of stay (LOS) (p < 0.001). The incorporation of the tubular dysfunction severity into the AKI staging system improved the prediction of PICU LOS. CONCLUSIONS: Tubular dysfunction was associated with both morbidity and mortality in critically ill children and its assessment may help to capture a more comprehensive picture of acute kidney insult.

Incidence of Hypophosphatemia After Intravenous Administration of Iron: A Matching-Adjusted Indirect Comparison of Data from Japanese Randomized Controlled Trials.

INTRODUCTION: Intravenous (IV) administration of iron is considered a safe and efficacious treatment for iron deficiency anemia (IDA), recommended in patients requiring rapid replenishment of iron, or intolerant or unresponsive to oral administration of iron. Recent randomized controlled trials (RCTs) have shown high incidence of hypophosphatemia after administration of two IV iron preparations: saccharated ferric oxide (SFO) and ferric carboxymaltose (FCM). The present study aimed to conduct matching-adjusted indirect comparison (MAIC) of hypophosphatemia incidence with these iron formulations and ferric derisomaltose (FDI) based on data from head-to-head RCTs conducted in Japan. METHODS: A MAIC of hypophosphatemia incidence was conducted on the basis of data from two head-to-head RCTs. The relative odds of hypophosphatemia with FDI versus SFO were obtained from patient-level data from a recent RCT and adjusted for cumulative iron dose, while parametric models of serum phosphate levels from a separate RCT were used to estimate the relative odds of hypophosphatemia with FCM with SFO. An anchored MAIC was then conducted comparing FDI with FCM. RESULTS: The adjusted odds of experiencing hypophosphatemia were significantly lower with FDI than SFO [odds ratio (OR) of 0.02; 95% confidence interval (CI) 0.01-0.05]. The parametric models of serum phosphate from the RCT comparing FCM with SFO provided an estimated OR of 1.17 for the incidence of hypophosphatemia with FCM versus SFO. Combining the two estimates in the MAIC showed that the odds of experiencing hypophosphatemia would be 52.5 (95% CI 27.7-99.4) times higher with FCM than FDI in patients with IDA associated with heavy menstrual bleeding in Japan. CONCLUSIONS: Direct comparison of patient-level data and a MAIC from two RCTs in Japanese patients with heavy menstrual bleeding indicated that hypophosphatemia is less frequent in patients treated with FDI than those with FCM or SFO. Results are in agreement with RCTs comparing FDI and FCM in patients with various etiologies conducted in the USA and Europe.

Elevated morbidity and mortality in patients with chronic idiopathic hypophosphatemia: a nationwide cohort study.

Background: Chronic idiopathic hypophosphatemia (CIH) induced by X-linked hypophosphatemic rickets or tumor-induced osteomalacia is a rare inherited or acquired disorder. However, due to its rarity, little is known about the epidemiology and natural course of CIH. Therefore, we aimed to identify the prevalence and long-term health outcomes of CIH patients. Methods: Using the Korean Health Insurance Review and Assessment claims database, we evaluated the incidence of hypophosphatemia initially diagnosed from 2003 to 2018. After excluding secondary conditions that could change serum phosphorus levels, we identified 154 patients (76 men and 78 women) with non-secondary and non-renal hypophosphatemia. These hypophosphatemic patients were compared at a ratio of 1:10 with age-, sex-, and index-year-matched controls (n = 1,540). Results: In the distribution of age at diagnosis, a large peak was observed in patients aged 1-4 years and small peaks were observed in ages from 40-70 years. The age-standardized incidence rate showed non-statistically significant trend from 0.24 per 1,000,000 persons in 2003 to 0.30 in 2018. Hypophosphatemic patients had a higher risk of any complication (adjusted hazard ratio [aHR], 2.17; 95% confidence interval [CI], 1.67-2.69) including cardiovascular outcomes, chronic kidney disease, hyperparathyroidism, osteoporotic fractures, periodontitis, and depression. Hypophosphatemic patients also had higher risks of mortality and hospitalization than the controls (aHR, 3.26; 95% CI, 1.83-5.81; and aHR, 2.49; 95% CI, 1.97-3.16, respectively). Conclusion: This first nationwide study of CIH in South Korea found a bimodal age distribution and no sex differences among patients. Hypophosphatemic patients had higher risks of complications, mortality, and hospitalization compared to age- and sex-matched controls.

Incidence and predictors of hypophosphataemia after ferric carboxymaltose use-A 3-year experience from a single institution in Singapore.

Ferric carboxymaltose (FCM) administration helps reduce transfusion requirements in the perioperative situation, which improves patient outcomes and reduces healthcare costs. However, there is increasing evidence of hypophosphataemia after FCM use. We aim to determine the incidence of hypophosphataemia after FCM administration and elucidate potential biochemical factors associated with the development of subsequent hypophosphataemia. A retrospective review of anonymised data of all FCM administrations in a single institution was conducted from August 2018 to August 2021. Each unique FCM dose administered was examined to assess its effect on Hb and serum phosphate levels within the subsequent 28 days from each FCM administration. Phosphate levels were repeatedly measured within the 28-day interval and the lowest phosphate level within that period was determined. Patients' serum phosphate levels within 28 days of FCM administration were compared against normal serum phosphate levels within 2 weeks before FCM administration. The odds ratios of various pre-FCM serum markers were calculated to elucidate potential biochemical predictors of post-FCM hypophosphataemia. In 3 years, a total of 1296 doses of FCM were administered to 1069 patients. The mean improvement in Hb was 2.45 g/dL (SD = 1.94) within 28 days of FCM administration, with the mean time taken to peak Hb levels being 6.3 days (SD = 8.63), which is earlier than expected, but was observed in this study and hence reported. The incidence of hypophosphataemia <0.8 mmol/L was 22.7% (n = 186), and <0.4 mmol/L was 1.6% (n = 9). This figure is lower than the numbers reported in previously published meta-analyses given that routine checks of serum phosphate levels were not conducted initially and hence could possibly be higher. The odds of developing hypophosphataemia (<0.8 mmol/L) were 27.7 (CI: 17.3-44.2, p < 0.0001) if baseline serum phosphate was less than 1 mmol/L. The odds of developing hypophosphataemia (<0.8 mmol/L) were 1.3 (CI: 1.08-1.59, p < 0.01) if the change in Hb levels observed after FCM administration were more than 4 g/dL. Hypophosphataemia after FCM administration is significant and FCM should be used by clinicians with caution.

Hypophosphatemia in infants with severe bronchiolitis and association with length of mechanical ventilation.

OBJECTIVES: Electrolyte disorders occurs frequently in children with bronchiolitis. The aim of the present study was to describe the frequency of hypophosphatemia and to evaluate its association with length of mechanical ventilation in infants admitted to a pediatric intensive care unit (PICU) with bronchiolitis. METHODS: This retrospective cohort study included infants aged between 7 days and 3 months admitted to a PICU between September 2018 and March 2020 and diagnosed with severe acute bronchiolitis requiring respiratory support. Infants with a chronic condition that could potentially be a confounding factor were excluded. The primary outcome was the frequency of hypophosphatemia (<1.55 mmol/L); the secondary outcomes were the frequency of hypophosphatemia during the PICU stay, and the association with length of mechanical ventilation (LOMV). RESULTS: Among the 319 infants admitted 178 had at least one phosphatemia value and were included in the study. The frequency of hypophosphatemia was 41% at PICU admission (61/148) and 46% during the PICU stay (80/172). The median [IQR] LOMV was significantly longer in children with hypophosphatemia at admission (109 [65-195] h vs. 67 [43-128] h, p = 0.007), and in multivariable linear regression lower phosphatemia at admission was associated with longer LOMV (p < 0.001) after controlling for severity (PELOD2 score) and weight. CONCLUSION: Hypophosphatemia was frequent in infants with severe bronchiolitis admitted to a PICU and was associated with a longer LOMV.

Hypophosphataemia definitions, incidence and associated outcomes in paediatric intensive care: A retrospective cohort study in post-cardiac surgical patients <2 years of age.

AIM: Hypophosphataemia has been linked to higher morbidity and mortality in intensive care but there is inconsistency in the definition of hypophosphataemia for infants and children. We aimed to determine the incidence of hypophosphataemia in a group of at-risk children in paediatric intensive care unit (PICU) and associations with patient characteristics and clinical outcomes using three different hypophosphataemia thresholds. METHODS: Retrospective cohort study of 205 post-cardiac surgical patients <2 years of age admitted to Starship Child Health PICU, Auckland, New Zealand. Patient demographics and routine daily biochemistry for 14 days after PICU admission were collected. Rates of sepsis, mortality and length of mechanical ventilation were compared between groups with different serum phosphate concentrations. RESULTS: Out of 205 children, 6 (3%), 50 (24%) and 159 (78%) had hypophosphataemia at thresholds of <0.7, <1.0 and <1.4 mmol/L, respectively. There were no differences in gestational age at birth, sex, ethnicity or mortality in those with and without hypophosphataemia at any threshold. Children with a serum phosphate <1.4 mmol/L had more mean (SD) total hours of mechanical ventilation (85.2 (79.6) vs. 54.9 (36.2) h, P = 0.02) and those with mean serum phosphate <1.0 mmol/L had more mean hours of mechanical ventilation (119.4 (102.8) vs. 65.2 (54.8) h, P < 0.0001), episodes of sepsis (14% vs. 5%, P = 0.03) and longer length of stay (6.4 (4.8-20.7) vs. 4.9 (3.9-6.8) days, P = 0.02). CONCLUSIONS: Hypophosphataemia is common in this PICU cohort and serum phosphate <1.0 mmol/L is associated with increased morbidity and length of stay.

Quality improvement project in a neonatal intensive care unit reduced the prevalence and duration of hypophosphatemia with significant and sustainable results.

BACKGROUND: Hypophosphatemia is associated with prolonged mechanical ventilation and may affect growth, bone mineralization, nephrocalcinosis, and mortality in preterm infants. Optimal nutrition practices may decrease risk for hypophosphatemia and improve outcome. METHODS: A quality improvement project was established to improve parenteral and enteral phosphorus intake with the goal to decrease prevalence and duration of hypophosphatemia in the first 14 days in infants <32 weeks' gestation. RESULTS: Among 406 preterm infants, the prevalence of moderate hypophosphatemia decreased from 44% to 19% (P < 0.01) over 4 years. The median duration of moderate hypophosphatemia decreased from 72 h (48-128) to 24 (24-53) (P < 0.01). Daily intakes of parenteral calcium and phosphorus on the fourth day of life increased from 1.5 to 2.5 mEq/kg/day (P < 0.01) and 0.6 to 1.3 mmol/kg/day (P < 0.01), respectively. The median postnatal age of first serum phosphorus concentration assessment decreased from 53 h (41-64) to 32 (24-40) (P < 0.01). CONCLUSION: During this quality improvement project, reduced prevalence and duration of hypophosphatemia in infants <32 weeks' gestation in the first 14 days of life was achieved through the optimization of parenteral and enteral phosphorus intake and improved response to acute hypophosphatemia.

[Hypophosphatemia after injectable iron treatments in adults: Comparison between ferric carboxymaltose and iron sucrose]. / Hypophosphorémie après traitement par fer injectable chez l'adulte : comparaison entre le carboxymaltose ferrique et l'hydroxyde ferrique-saccharose.

Hypophosphatemia is a recognized side effect of treatment of iron deficiency anemias with injectable iron. We analyzed 35 clinical trials that used ferric carboxymaltose (FCM) or iron sucrose (IS). Hypophosphatemia prevalence ranged from 0 to 91.7%. FCM-induced a significant (P<0.001) greater hypophosphatemia prevalence and phosphatemia decrease than IS (52.0% [95% CI: 42.2-61.8%] vs. 7.7% [95% CI: -2.8 to 18.2%] and -1.12mmol/L [95% CI: -1.36 to -0.89mmol/L] vs. -0.13mmol/L [95% CI: -0.59 to 0.32mmol/L]). FCM-induced hypophosphatemia was dose-dependent. The nadir of hypophosphatemia was reached in almost all studies after 7 and 14days. Hypophosphatemia persisted at the end of the study in 53.8% of the reported studies that used FCM and lasted up to 6months. FCM-induced an increase in intact circulating fibroblast growth factor 23 and in renal phosphorus excretion while serum 1-25 dihydroxyvitamin D was decreased. Risk factors for hypophosphatemia after FCM therapy were low basal circulating phosphate or ferritin, low body weight, high glomerular filtration rate, serum parathyroid hormone or hemoglobin and age, whereas renal insufficiency was associated with a lower risk. In conclusion, hypophosphatemia is common after treatment with injectable iron, FCM being associated with a higher risk than IS and with disorders of phosphocalcium metabolism. Monitoring of blood phosphate and 1-25 dihydroxyvitamin D could be considered during FCM therapy.

The importance of hypophosphatemia in the clinical management of primary hyperparathyroidism.

AIM: The levels of serum phosphorus (P) are low or low-normal in primary hyperparathyroidism (PHPT), and there is an inverse relationship between the levels of parathormone (PTH) and P. However, when considering the diagnostic and surgical indication criteria of PHPT, serum P levels are generally ignored. The aim of this study was to retrospectively evaluate the association of serum P levels with the clinical outcomes of PHPT. MATERIALS AND METHODS: A retrospective evaluation was made of the data of 424 consecutive patients (370 females, 54 males) with PHPT who presented at our centre. RESULTS: The mean age of the study population was 57 ± 11.68 years. The mean P was 2.57 ± 0.53 mg/dl. Asymptomatic disease was determined in 199 (47%) patients. Male patients had significantly lower levels of P. Symptomatic patients and patients with renal stones, vitamin D < 20 µg/l, calcium level ≥ 11.2 mg/dl, 24 h urinary calcium > 400 mg/day, or hypomagnesemia, were seen to have significantly lower levels of P (p < 0.05). Hypophosphatemia (hypoP) was found in 202 of 424 patients (47%), and these patients had a higher rate of symptomatic disease (63% to 44%, p < .0001). Of the 61 (88%) patients with moderate hypoP, 54 (88%) had at least one of the surgical criteria. A statistically significant increase in the incidence of hypoP was determined in symptomatic and male patients. In the patients with hypoP, serum PTH and urine calcium levels were found to be higher, and lumbar T-scores and serum vitamin D levels were lower. The patients with hypoP had higher rates of renal stones and osteoporosis (p < 0.05). CONCLUSIONS: The current study results show that hypoP is associated with a higher risk of osteoporosis and renal stones in PHPT patients. Even if patients are asymptomatic, moderate hypoP may be associated with poor outcomes of PHPT. Therefore, moderate hypoP may be a new criterion for parathyroidectomy, regardless of hypercalcemia level.

Hypophosphataemia risk associated with ferric carboxymaltose in heart failure: A pooled analysis of clinical trials.

AIMS: Iron deficiency is a common finding among patients with heart failure (HF) and is associated with adverse outcomes, including decreased quality of life, increased risk of hospitalization, and decreased survival. Intravenous ferric carboxymaltose (FCM) has been shown to improve outcomes among patients with HF and concomitant iron deficiency, but FCM is associated with an increased risk of hypophosphataemia. We aimed to better characterize this risk among HF populations. METHODS AND RESULTS: This pooled analysis examined data from 41 studies of adults with iron deficiency across disease states and therapeutic areas. Among the 7931 patients treated with FCM available for analysis, 14% made up the HF subgroup. Additional subgroups included women's health (36%), non-dialysis-dependent chronic kidney disease (NDD-CKD; 27%), haemodialysis-dependent chronic kidney disease (HD-CKD; 1%), gastrointestinal (10%), neurology (3%), and other (10%). The incidence of post-baseline moderate or severe hypophosphataemia (i.e. serum phosphate [PO4 3- ] level <2.0 mg/dL) varied across the therapeutic areas, with the lowest incidences observed in the HD-CKD (0%), HF (8.1%), and NDD-CKD (12.8%) subgroups. The prevalence of moderate or severe hypophosphataemia among the women's health, other, gastrointestinal, and neurology subgroups was 30.1%, 40.6%, 51.0%, and 55.6%, respectively. In the HF subgroup, one patient (<0.1%) had a serum PO4 3- of <1.0 mg/dL recorded, compared with 4.8% and 4.0% of the subjects in the neurology and gastrointestinal groups, respectively. With the exception of the HD-CKD subgroup, mean serum PO4 3- levels decreased through weeks 2 to 4, and then returned toward baseline and plateaued by week 8. The strongest predictor of hypophosphataemia was preserved kidney function (estimated glomerular filtration rate: >60 mL/min/1.73 m2 vs. <30 mL/min/1.73 m2 ; odds ratio: 12.2). Among patients in the HF subgroup, the incidence of treatment-emergent adverse events potentially related to hypophosphataemia (e.g. cardiac failure, ventricular tachyarrhythmias, fatigue, muscle weakness, bone pain, neurological symptoms, and muscle pain) was lower among FCM-treated patients than among those receiving placebo, and lower among patients with a post-baseline PO4 3- <2 mg/dL vs. those not meeting such criteria. CONCLUSIONS: The risk of laboratory-assessed hypophosphataemia in HF patients treated with FCM was lower than that seen in patients in other therapeutic areas treated with FCM, and clinical events associated with hypophosphataemia are uncommon with FCM therapy in this population. Appropriate monitoring, particularly soon after administration in the unlikely event of repeated dosing in HF patients, will allow for further refinement of management strategies. [Correction added on 24 February 2023, after first online publication: In the preceding sentence, "…administration, will allow…" has been corrected to "…administration in the unlikely event of repeated dosing in HF patients, will allow…" in this version.].

Impact of Nutritional Management on Survival of Critically Ill Malnourished Patients with Refeeding Hypophosphatemia.

BACKGROUND: Early nutritional therapy may aggravate hypophosphatemia in critically ill patients. AIM: To investigate the influence of the type nutritional therapy on the survival of critically-ill malnourished patients at refeeding hypophosphatemia risk. METHODS: Retrospective cohort study including malnourished, critically-ill adults, admitted from June 2014-December 2017 in an intensive care unit (ICU) at a tertiary hospital. Refeeding hypophosphatemia risk was defined as low serum phosphorus levels (<2.5 mg/dL) seen at two timepoints: before the initiation and at day 4 of the nutritional therapy. Patients receiving enteral nutrition (EN) were compared with those receiving supplemental parenteral nutrition (SPN-EN plus parenteral nutrition). Primary outcome was 60 d survival. Secondary endpoint was the incidence of refeeding hypophosphatemia risk. RESULTS: We included 468-321 patients (68.6%) received EN and 147 (31.4%) received SPN. The mortality rate was 36.3% (n = 170). Refeeding hypophosphatemia risk was found in 116 (24.8%) patients before and in 177 (37.8%) at day 4 of nutritional therapy. The 60 d mean survival probability was greater for patients receiving SPN both before (42.4 vs. 22.4%, p = 0.005) and at day 4 (37.4 vs. 25.8%, p = 0.014) vs. patients receiving EN at the same timepoints. Cox regression showed a hazard ratio of 3.3 and 2.4 for patients at refeeding hypophosphatemia risk before and at day 4 of EN, respectively, compared to the SPN group at the same timepoints. CONCLUSION: Refeeding hypophosphatemia risk was frequent in malnourished ICU patients and the survival for patients receiving SPN seemed associated with better survival than EN only.

The Association Between Hypophosphatemia and Lactic Acidosis After Cardiac Surgery With Cardiopulmonary Bypass: A Retrospective Cohort Study.

OBJECTIVES: The clinical significance of hypophosphatemia in cardiac surgery has not been investigated extensively. The aim of this study was to evaluate the association of postoperative hypophosphatemia and lactic acidosis in cardiac surgery patients at the time of intensive care unit (ICU) admission. DESIGN: A retrospective cohort study. SETTING: At a single academic center. PARTICIPANTS: Patients who underwent nontransplant cardiac surgery with cardiopulmonary bypass between August 2009 and December 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Serum phosphate and lactate levels were measured upon ICU admission in patients undergoing nontransplant cardiac surgery with cardiopulmonary bypass. There were 681 patients in the low-phosphate (<2.5 mg/dL) group and 2,579 patients in the normal phosphate group (2.5-4.5 mg/dL). A higher proportion of patients in the low phosphate group (26%; 179 of 681; 95% CI: 23-30) had severe lactic acidosis compared to patients in the normal phosphate group (16%; 417 of 2,579; 95% CI: 15-18). In an unadjusted logistic regression model, patients in the low phosphate group had 1.9-times the odds of having severe lactic acidosis (serum lactate ≥4.0 mmol/L) when compared to patients in the normal phosphate group (95% CI: 1.5-2.3), and still 1.4-times the odds (95% CI: 1.1-1.7) after adjusting for several possible confounders. CONCLUSIONS: Hypophosphatemia is associated with lactic acidosis in the immediate postoperative period in cardiac surgery patients. Future studies will need to investigate it as a potential treatment target for lactic acidosis.

Incidence, evolution and risk factors of hypophosphatemia in patients with solid tumors receiving ferric carboxymaltose: a retrospective cohort study.

OBJECTIVES: Ferric carboxymaltose (FCM) is increasingly used in the management of cancer-related anemia, yet it may cause hypophosphatemia. This retrospective study describes the incidence, evolution and risk factors of hypophosphatemia in a cohort of patients with solid tumors receiving FCM. METHODS: Serum phosphorus concentration was assessed longitudinally using a random intercepts model. The probability of developing hypophosphatemia, as graded by CTCAE version 4.0, was investigated using a multi-state model. Transition hazards were modeled non-parametrically and semi-parametrically by a Cox model. Causal marginal risk differences between baseline interventions on serum phosphorus and/or FCM dose were obtained via G-computation. RESULTS: In 174 ambulatory patients with solid tumors receiving FCM at two university hospitals between October 2020 and September 2021, the risk of developing moderate-to-severe hypophosphatemia was 36.0% (95% confidence interval (CI) 28.2-43.9%) and peaked within 16 days after first FCM administration. The average duration of moderate-to-severe hypophosphatemia was 12.4 days. After adjustment for confounders, lower baseline serum phosphorus (adjusted hazard ratio (aHR) 0.88 per 0.1 mmol/L increase, 95% CI 0.79-0.98) and higher FCM dose (first dose: aHR 1.12 per 1 mg/kg increase, 95% CI 1.01-1.25; second dose: aHR 1.06 per 1 mg/kg increase, 95% CI 1.00-1.13) significantly increased the hazard of moderate-to-severe hypophosphatemia. CONCLUSION: Approximately one out of three ambulatory patients with solid tumors may develop moderate-to-severe hypophosphatemia after FCM administration. Baseline serum phosphorus and FCM dose may be modifiable risk factors that should be considered for intervention in order to mitigate the risk of hypophosphatemia.

A Retrospective Chart Review to Determine Hypophosphatemia Incidence and Phosphorus Supplementation Requirements in Patients With Severe Thermal Cutaneous Injuries Receiving High-Volume Hemofiltration.

Patients with severe thermal injuries have increased metabolic demands necessitating frequent phosphate supplementation. Patients with acute renal failure may have less requirements, due to reduced elimination. However, patients being supported with renal replacement therapy have varying degree of requirements. Little published evidence depicts the incidence of hypophosphatemia and repletion requirements in patients with severe thermal injuries treated with high-volume hemofiltration (HVHF) and a high-flux membrane. The objective of this retrospective chart review was to determine the incidence of hypophosphatemia and characterize repletion requirements and response in this population. Enrolled patients had at least 20% TBSA thermal injuries and required continuous hemofiltration with prefilter replacement fluid doses ≥35 mL/kg IBW/hr. A randomly selected cohort without acute kidney injury (AKI) and matched based on age and extent of TBSA was used to compare phosphorus requirements over an initial 14-day period. Demographics, diet, and variables affecting phosphorus concentrations were collected. Sixteen patients were included in the retrospective HVHF group and 16 patients in a case-control cohort to better depict the impact of HVHF. The average age was 60.2 ± 15.1 years and median TBSA was 30% (23.4, 56.3) in the HVHF group, compared to 53.3 ± 16.4 years (P = .22) and TBSA 29% (26.4, 33.9; P = .73). All patients in the HVHF group were started on HVHF with a 1.6 m2 polyethersulfone membrane for AKI. As expected, the HVHF group exhibited statistically higher than normal baseline potassium and phosphorous laboratory values. The HVHF group experienced more days with hypophosphatemia (49.6 ± 12.4% vs 29.3 ± 16.3%, P = .012), despite 0.75 mmol/kg/day phosphorous supplementation (compared to 0.66 mmol/kg/day for the control group, P = .45). Patients with longer durations of HVHF therapy experienced increasing risk of hypophosphatemia, reaching 100% by the end of the study period. This study demonstrates severe thermally injured patients receiving HVHF for AKI are at increased risk for hypophosphatemia, and require high phosphate supplementation.

Identification of risk factors for iatrogenic hypophosphatemia: A retrospective case-control study.

BACKGROUND AND OBJECTIVES: To investigate the iatrogenic risk factors for hypophosphatemia in intensive care unit (ICU) patients. METHODS AND STUDY DESIGN: A total of 120 patients were enrolled and further divided into 4 groups, namely normal, mild, moderate or severe, according to the degree of hypophosphatemia. A number of related factors were analyzed and compared among the 4 groups, including the treatment method and outcomes. Univariate and multivariate regression analyses were employed to identify and confirm the risk factors associated with the occurrence of hypophosphatemia. RESULTS: The results revealed that the acute physiology and chronic health evaluation II (APACHEII), Sequential Organ Failure Assessment (SOFA), modified NUTrition Risk in Critically ill (NUTRIC) scores as well as the length of patient stays in ICUs exhibited a gradually increasing trend of aggravation of hypophosphatemia. Univariate regression analysis identified the use of dehydrating drugs to be closely associated with the occurrence of hypophosphatemia, which was further confirmed by a multivariate regression analysis. CONCLUSIONS: The use of dehydrating drugs led to hypophosphatemia; therefore blood phosphorus concentrations should be closely monitored during treatment of ICU patients.

Early hypophosphatemia in critically ill children and the effect of parenteral nutrition: A secondary analysis of the PEPaNIC RCT.

BACKGROUND & AIMS: Hypophosphatemia during critical illness has been associated with adverse outcome. The reintroduction of enteral or parenteral nutrition, leading to refeeding hypophosphatemia (RFH), has been presented as potential risk factor. We investigated the occurrence of early RFH, its association with clinical outcome, and the impact of early parenteral nutrition (PN) on the development of early RFH in pediatric critical illness. METHODS: This is a secondary analysis of the PEPaNIC randomized controlled trial (N = 1440), which showed that withholding supplemental parenteral nutrition (PN) for 1 week (late-PN) in the pediatric intensive care unit (PICU) accelerated recovery and reduced new infections compared to early-PN (<24 h). Patients with renal replacement therapy or unavailable phosphate concentrations were excluded from this analysis. Early RFH was defined as serum/plasma phosphate <0.65 mmol/L and a drop of >0.16 mmol/L within 3 days of admission to the PICU. The association between baseline characteristics and early RFH, and the association of early RFH with clinical outcome were investigated using logistic and linear regression models, both uncorrected and corrected for possible confounders. To examine the impact of nutritional intake on phosphate concentrations, structural nested mean models with propensity score and censoring models were used. RESULTS: A total of 1247 patients were eligible (618 early-PN, 629 late-PN). Early RFH occurred in 40 patients (3%) in total, significantly more in the early-PN group (n = 31, within-group occurrence 5%) than in the late-PN-group (n = 9, within-group occurrence 1%, p < 0.001). Patients who were older (OR 1.14 (95% CI 1.08; 1.21) per year added, p < 0.001) and who had a higher Pediatric Risk of Mortality (PIM3) score had a higher risk of developing early RFH (OR 1.36 (95% CI 1.15; 1.59) per unit added, p < 0.001), whereas patients in the late-PN group had a lower risk of early RFH (OR 0.24 (95% CI 0.10; 0.49), p < 0.001). Early RFH was significantly associated with a 56% longer PICU stay (p = 0.003) and 42% longer hospital stay (p = 0.007), but not with new infections (OR 2.01 (95% CI 0.90; 4.30), p = 0.08) or length of mechanical ventilatory support (OR 1.05 (95% CI -3.92; 6.03), p = 0.68), when adjusted for possible confounders. Increase of parenteral nutrition intake (in % kcal of predicted resting energy expenditure) decreased phosphate concentrations (c = -0.002 (95% CI -0.002; -0.001). CONCLUSIONS: Early RFH occurred in 3% of critically ill children. Patients randomized to late-PN had a lower chance of developing early RFH, which may be explained by the more gradual build-up of nutrition. As early RFH might impact recovery, it is important to closely monitor phosphate concentrations in patients, especially of those at risk for early RFH.