The association between serum phosphate and length of hospital stay and all-cause mortality in adult patients: a cross-sectional study.

BACKGROUND: Data is limited on the prevalence of hypophosphatemia in general hospitalized patients, and its association with length of hospital stay (LOS) and mortality remained unclear. We aimed to investigate the prevalence of admission phosphate abnormality and the association between serum phosphate level and length of hospital stay and all-cause mortality in adult patients. METHODS: This was a multi-center retrospective study based on real-world data. Participants were classified into five groups according to serum phosphate level (inorganic phosphorus, iP) within 48 h after admission: G1, iP < 0.64 mmol/L; G2, iP 0.64-0.8 mmol/L; G3, iP 0.8-1.16 mmol/L; G4, iP 1.16-1.45 mmol/L; and G5, iP ≥ 1.45 mmol/L, respectively. Both LOS and in-hospital mortality were considered as outcomes. Clinical information, including age, sex, primary diagnosis, co-morbidity, and phosphate-metabolism related parameters, were also abstracted from medical records. RESULTS: A total number of 23,479 adult patients (14,073 males and 9,406 females, aged 57.7 ± 16.8 y) were included in the study. The prevalence of hypophosphatemia was 4.74%. An "L-shaped" non-linear association was determined between serum phosphate level and LOS and the inflection point was 1.16 mmol/L in serum phosphate level. Compared with patients in G4, patients in G1, G2 or G3 were significantly associated with longer LOS after full adjustment of covariates. Each 0.1 mmol/L decrease in serum phosphate level to the left side of the inflection point led to 0.64 days increase in LOS [95% confidence interval (CI): 0.46, 0.81; p for trend < 0.001]. But there was no association between serum phosphate and LOS where serum levels of phosphate ≥ 1.16 mmol/L. Multivariable logistic regression analysis showed that adjusted all-cause in-hospital mortality was 3.08-fold greater in patients in G1 than those in G4 (95% CI: 1.52, 6.25; p for trend = 0.001). Similarly, no significant association with either LOS or mortality were found in patients in G5, comparing with G4. CONCLUSIONS: Hypophosphatemia, but not hyperphosphatemia, was associated with LOS and all-cause mortality in adult inpatients. It is meaningful to monitor serum levels of phosphate to facilitate early diagnosis and intervention.

Hypophosphataemia and late-onset sepsis in extremely preterm neonates: A case-control study.

AIM: Late-onset sepsis (LOS) is common in extreme prematurity. These infants are at risk of refeeding syndrome-associated hypophosphataemia. Our objective was to investigate whether hypophosphataemia predisposes to LOS in extremely premature neonates. METHODS: A retrospective case-control study of neonates born before 29 weeks' gestation in an Australian NICU from 2016 to 2020. Cases developed LOS or localised infection. Two controls, matched within 2 gestational weeks and 90 calendar days, were selected per case. RESULTS: Amongst 48 cases and 93 controls, cases were smaller at birth (767 g vs. 901 g, P = 0.01), but were otherwise comparable. Hypophosphataemia was more common in cases (26% vs. 15%, P = 0.18). Increased intravenous protein intake in the first week was protective against LOS (OR = 0.9, 95% CI 0.76-1.00, P = 0.04); median 2.1 g/kg/day in cases, 2.3 g/kg/day in controls. CONCLUSIONS: Hypophosphataemia as part of refeeding syndrome is prevalent and under-recognised in extremely premature neonates. We did not find an association between hypophosphataemia and LOS. Low intravenous protein may be an independent risk factor for infection.

[Prevalence of hypophosphatemia in children with diabetic ketoacidosis and treatment with subcutaneous regular insulin. Observational study]. / Prevalencia de Hipofosfatemia en niños con cetoacidosis diabética y tratamiento con insulina regular subcutánea. Estudio observacional.

Diabetic ketoacidosis (DKA) is one of the most serious complications of type 1 diabetes mellitus. Its treatment requires fluid and electrolyte replacement and insulin. Hypophosphatemia as a complication of treatment has been scarcely evaluated. OBJECTIVES: To estimate the incidence of hypophosphatemia in children with DKA, treated with subcutaneous regular insulin (IRS), and to explore factors associated with this complication. PATIENTS AND METHOD: Prospective, observational study. Patients diagnosed with DKA hospitalized in the general care ward were included. Data on phosphatemia, glycemia, acid-base status, and IRS amount (U/kg) received were recorded at baseline and after 24 h of treatment. Hypophosphatemia was defined as values below 2.5 mg/dl. The correlation between initial phosphate and at 24 h of treatment was evaluated; the incidence of hypophosphatemia at 24 h was expressed as a percentage of the total number of patients. RESULTS: 30 patients were included, 15 were female, mean age 11.4 ± 3.2 years. At 24 h of treatment with IRS, 36.7% (95%CI 22-55%) presented hypophosphatemia, mean value 1.9 ± 1.5 mg/dl. Initial bicarbonate < 10 mmol/L acted as a predictor of hypophosphatemia (OR 7.5; 95%CI 1.4-39.8%; p = 0.01). No patient required intravenous phosphate correction, and no associated clinical complications were observed. CONCLUSION: In the group studied, the incidence of hypophosphatemia reached 36.7% at 24 hours of treatment. Initial bicarbonate lower than 10 mmol/L was significantly associated with hypophosphatemia. No complications associated with hypophosphatemia were observed.

Incidence of hypophosphataemia after ICU admission in mechanically ventilated patients and its relationship with risk factors for refeeding syndrome.

OBJECTIVE: To describe the incidence of hypophosphatemia in patients admitted to the ICU who have required mechanical ventilation. To analyze the presence of risk factors and its relationship with nutritional practice. DESIGN: Prospective observational study. SETTING: Polyvalent ICUs of 2 University Hospitals. PATIENTS OR PARTICIPANTS: Patients on invasive mechanical ventilation ≥72 h with normal level of phosphorus at admission. INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: Electrolyte levels (phosphorus, magnesium, potassium) were determined on admission to the ICU and at 96 h. Risk categories on admission, caloric intake, insulin doses and acid-base status during the first 4 days of admission were recorded. Incidence was calculated as the number of patients who developed hypophosphataemia after admission. Univariate analysis was performed for between-group comparison and multivariate analysis of potential risk factors. RESULTS: 89 patients were included. The incidence of hypophosphataemia was 32.6%. In these patients phosphorus decreased from 3.57 ±â€¯1.02 mmol/l to 1.87 ±â€¯0.65 mmol/l (52.3%). The mean kcal/kg/24 h provided in the first 4 days was 17.4 ±â€¯4.1, with no difference between the group that developed hypophosphataemia and the group that did not. Significant risk factors were insulin doses administered and pH and PaCO2 values. CONCLUSIONS: The incidence of hypophosphataemia at 96 h from admission in mechanically ventilated patients is high and unrelated to the risk category and hypocaloric nutritional practice used. Insulin dosis and acid-base status are the main determinants of its occurrence.

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.

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.

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.

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.

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.

[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.

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.

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.].

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.