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.

Early Hypophosphatemia as a Prognostic Marker in Acute Pancreatitis.

OBJECTIVES: Acute pancreatitis (AP) is a complex disease representing a significant portion of gastrointestinal-related hospitalizations in the U.S. Understanding risk factors of AP might provide attractive therapeutic targets. We evaluated hypophosphatemia a prognostic marker in AP. METHODS: We performed a retrospective review of electronic health records of patients with AP from 01/ 01/2012-12/31/2021 at Cedars-Sinai Medical Center with serum phosphate measured within 48 hours of admission. Multivariable logistic regression modeling was used to evaluate associations with ICU admission and AP severity. Multivariable log-linear modeling was employed to examine associations with length of stay (LOS). RESULTS: Of 1526 patients admitted for AP, 33% (499) had a serum phosphate level measured within 48 hours. Patients with hypophosphatemia were more likely to have ICU admission (adjusted odds ratio (AOR) = 4.57; 95% confidence interval (CI): 2.75-7.62; P < 0.001), have a longer hospital stay (log-LOS = 0.34; SE; 0.09; 95% CI: 0.17-0.52; P < 0.001), and have moderate or severe AP (AOR = 1.80; 95% CI: 1.16-2.80; P < 0.001) compared with those without hypophosphatemia. CONCLUSION: Serum phosphate is infrequently measured in patients with AP and shows promise as an early prognostic marker for outcomes of AP.

Clinical, biochemical and genetic findings in adult patients with chronic hypophosphatasemia.

PURPOSE: The study aimed to define the clinical, biochemical and genetic features of adult patients with osteopenia/osteoporosis and/or bone fragility and low serum alkaline phosphatase (sALP). METHODS: Twenty-two patients with at least two sALP values below the reference range were retrospectively enrolled after exclusion of secondary causes. Data about clinical features, mineral and bone markers, serum pyridoxal-5'-phosphate (PLP), urine phosphoethanolamine (PEA), lumbar and femur bone densitometry, and column X-ray were collected. Peripheral blood DNA of each participant was analyzed to detect ALPL gene anomalies. RESULTS: Pathogenic ALPL variants (pALPL) occurred in 23% and benign variants in 36% of patients (bALPL), while nine patients harbored wild-type alleles (wtALPL). Fragility fractures and dental anomalies were more frequent in patients harboring pALPL and bALPL than in wtALPL patients. Of note, wtALPL patients comprised women treated with tamoxifen for hormone-sensitive breast cancer. Mineral and bone markers were similar in the three groups. Mean urine PEA levels were significantly higher in patients harboring pALPL than those detected in patients harboring bALPL and wtALPL; by contrast, serum PLP levels were similar in the three groups. A 6-points score, considering clinical and biochemical features, was predictive of pALPL detection [P = 0.060, OR 1.92 (95% CI 0.972, 3.794)], and more significantly of pALPL or bALPL [P = 0.025, OR 14.33 (95% CI 1.401, 14.605)]. CONCLUSION: In osteopenic/osteoporotic patients, single clinical or biochemical factors did not distinguish hypophosphatasemic patients harboring pALPL or bALPL from those harboring wtALPL. Occurrence of multiple clinical and biochemical features is predictive of ALPL anomalies, and, therefore, they should be carefully identified. Tamoxifen emerged as a hypophosphatasemic drug.

Prolonged Hypophosphatemia and Intensive Care After Curative Surgery of Tumor Induced Osteomalacia: A Case Report.

Introduction: Rare FGF23-producing mesenchymal tumors lead to paraneoplastic tumor-induced osteomalacia (TIO) presenting with phosphate wasting, hypophosphatemia, chronic hypomineralization of the bone, fragility fractures and muscle weakness. Diagnosis of TIO requires exclusion of other etiologies and careful search for a mesenchymal tumor that often is very small and can appear anywhere in the body. Surgical removal of the tumor is the only definitive treatment of TIO. Surgical complications due to chronic hypophosphatemia are not well recognized. Case Description: The current case describes severe fragility fractures in a 58-year-old woman, who lost her ability to walk and was bedridden for two years. First, the initial diagnostic laboratory work-up did not include serum phosphorus measurements, second, the suspicion of adverse effects of pioglitazone as an underlying cause delayed correct diagnosis for at least two years. After biochemical discovery of hyperphosphaturic hypophosphatemia at a tertiary referral centre, a FGF23-producing tumor of the mandible was discovered on physical examination, and then surgically removed. Postoperatively, severe hypophosphatemia and muscle weakness prolonged the need for ventilation support, intensive care and phosphate supplementation. After two years of rehabilitation, the patient was able to walk short distances. The tumor has not recurred, and serum phosphate concentration has remained within normal limits during 3.5 years of follow-up. Conclusions: The case report illustrates knowledge gaps in the diagnostic work-up of rare causes of low bone mass and fragility fractures. Compared to other low phosphate conditions, surgical recovery from TIO-induced hypophosphatemia warrants special attention. Increased alkaline phosphatase concentration may indicate impaired postsurgical recovery due to prolonged hypophosphatemia, underlining the need for proactive perioperative correction of hypophosphatemia.

Association between phosphate disturbances and mortality among critically ill patients with sepsis or septic shock.

OBJECTIVE: The aim of this study is to examine the association of hypophosphatemia and hyperphosphatemia on the first day of ICU admission with mortality in septic critically ill patients. METHODS: In this retrospective cohort study, all adult patients who were admitted to the medical-surgical ICUs between 2014 and 2017 with sepsis or septic shock were categorized as having hypophosphatemia, normophosphatemia and hyperphosphatemia based on day 1 serum phosphate values. We compared the clinical characteristics and outcomes between the three groups. We used multivariate analysis to examine the association of hypophosphatemia and hyperphosphatemia with these outcomes. RESULTS: Of the 1422 patients enrolled in the study, 188 (13%) had hypophosphatemia, 865 (61%) normophosphatemia and 369 (26%) had hyperphosphatemia. The patients in the hyperphosphatemia group had significantly lower GCS, higher APACHE II scores, higher serum creatinine, increased use of vasopressors, and required more mechanical ventilation with lower PaO2/FiO2 ratio compared with the other two groups. In addition, the hyperphosphatemia group showed significantly higher ICU and hospital mortality in comparison with the other two groups. CONCLUSION: Hyperphosphatemia and not hypophosphatemia on the first ICU admission day was associated with an increase in the ICU and hospital mortality in septic critically ill patients.

Intravenous ferric derisomaltose for the treatment of iron deficiency anemia.

Intravenous (IV) iron is the therapy of choice when oral iron is ineffective or poorly tolerated, yet use has been limited by fears of hypersensitivity reactions (HSRs). Newer formulations that bind iron more tightly and release it more slowly have made the risk of serious or severe HSRs very low. One such formulation, ferric derisomaltose, has been approved in the United States for delivery of 1000 mg iron in a single IV infusion. Ferric derisomaltose rapidly repletes iron parameters with low rates of serious or severe HSRs. Single-infusion iron repletion offers convenience, eliminates adherence concerns, and reduces healthcare resource utilization.

Hyperphosphatemia rather than hypophosphatemia indicates a poor prognosis in patients with sepsis.

BACKGROUND: Sepsis is the leading cause of hospitalization and death in the intensive care unit. It is vital to identify high-risk patients with poor prognosis in the early stages of sepsis. We aimed to investigate the prognostic value of serum phosphorus levels for sepsis. METHODS: The data of 4767 patients with sepsis were collected from the Multiparameter Intelligent Monitoring in Intensive Care III database. The Locally Weighted Scatterplot Smoothing technique and Kaplan-Meier analysis were used to test the crude relationship between serum phosphorus levels and mortality or overall survival. The multivariable logistic regression was used to further analyze the relationship between serum phosphorus levels and in-hospital mortality. The subgroup analysis was performed according to renal failure, use of vasopressin and the Sequential Organ Failure Assessment (SOFA) score. RESULTS: Only hyperphosphatemia significantly correlated with in-hospital mortality [odds ratio (OR) 1.48; 95% confidence interval (CI) 1.19-1.85], while the correlation between hypophosphatemia and in-hospital mortality was not significant (OR 0.91; 95% CI 0.70-1.19). The interactions between serum phosphorus and renal failure, use of vasopressin or the SOFA score were not significant. CONCLUSIONS: Hyperphosphatemia rather than hypophosphatemia indicates a poor prognosis in patients with sepsis.

New onset adrenal insufficiency in a patient with COVID-19.

SARS-CoV-2 is the cause of COVID-19. Since the outbreak and rapid spread of COVID-19, it has been apparent that the disease is having multi-organ system involvement. Still its effect in the endocrine system is not fully clear and data on cortisol dynamics in patients with COVID-19 are not yet available. SARS-CoV-2 can knock down the host's cortisol stress response. Here we present a case of a 51-year-old man vomiting for 10 days after having confirmed COVID-19 infection. He had hypotension and significant hyponatraemia. Work-up was done including adrenocorticotropic hormone stimulation test. He was diagnosed as suffering from adrenal insufficiency and started on steroids with subsequent improvement in both blood pressure and sodium level. COVID-19 can cause adrenal insufficiency. Clinicians must be vigilant about the possibility of an underlying relative cortisol deficiency in patients with COVID-19.

Utility of blood tests in screening for metabolic disorders in kidney stone disease.

OBJECTIVES: To determine the clinical utility of blood tests as a screening tool for metabolic abnormalities in patients with kidney stone disease. SUBJECTS AND METHODS: Clinical and biochemical data from 709 patients attending the Oxford University Hospitals NHS Foundation Trust for assessment and treatment of kidney stones were prospectively collected between April 2011 and February 2017. Data were analysed to determine the utility of serum calcium, parathyroid hormone (PTH), urate, chloride, bicarbonate, potassium and phosphate assays in screening for primary hyperparathyroidism, normocalcaemic hyperparathyroidism, hyperuricosuria, distal renal tubular acidosis (dRTA) and hypercalciuria. RESULTS: An elevated serum calcium level was detected in 2.3% of patients. Further investigations prompted by this finding resulted in a diagnosis of primary hyperparathyroidism in 0.2% of men and 4.6% of women for whom serum calcium was recorded. An elevated serum PTH level in the absence of hypercalcaemia was detected in 15.1% of patients. Of these patients, 74.6% were vitamin D-insufficient; no patients were diagnosed with normocalcaemic hyperparathyroidism. Hyperuricosuria was present in 21.6% of patients and hypercalciuria in 47.1%. Hyperuricaemia was not associated with hyperuricosuria, nor was hypophosphataemia associated with hypercalciuria. No patient was highlighted as being at risk of dRTA using serum chloride and bicarbonate as screening tests. CONCLUSION: This study indicates that individuals presenting with renal calculi should undergo metabolic screening with a serum calcium measurement alone. Use of additional blood tests to screen for metabolic disorders is not cost-effective and may provide false reassurance that metabolic abnormalities are not present. A full metabolic assessment with 24-h urine collection should be undertaken in recurrent stone formers and in those at high risk of future stone disease to identify potentially treatable metabolic abnormalities.

Intravenous iron: do we adequately understand the short- and long-term risks in clinical practice?

Intravenous (IV) iron as a therapeutic agent is often administered but not always fully understood. The benefits of IV iron are well proven in many fields, particularly in nephrology. IV iron is beneficial not only for true iron deficiency but also for iron-restricted anaemia (functional iron deficiency). Yet, the literature on intravenous iron has many inconsistencies regarding its adverse effects. Over the last several years, newer forms of iron have been developed, leading to the more regular use of iron and in larger doses. This review will summarize some of the older and newer literature regarding the differences among iron products, including the mechanisms and frequency of their adverse events (AEs). The pathway and frequency of an underrecognized adverse event (hypophosphataemia) will be discussed. Recent insights on infection risk and iron handling by macrophages are examined. Potential but presently unproven risks of iron overload due to IV iron are discussed. The impact of these on the risk:benefit ratio and dosing of intravenous iron are considered in different clinical settings, including pregnancy and cancer. IV iron is an essential component of the therapy of anaemia and understanding these issues will enable more informed treatment decisions and knowledgeable use of these drugs.

[Pediatric reference values for alkaline phosphatase and pathophysiological variations]. / Valeurs de référence de la phosphatase alcaline en pédiatrie et variations physiopathologiques.

Alkaline phosphatase activity is a parameter included in biochemical liver test. These isoenzymes are of various cellular origin inducing physiological variations on age and sex. The alkaline phosphatase activity standardization as well as numerous international studies have made it possible to standardize the pediatric reference values. The hyperphosphatasemia etiologies are very well know but the hypophosphatasemia are hardly explored and can allow the diagnosis of pathologies including hypophosphatasia, a rare treatable disease.

Severe hypophosphataemia following oral bisphosphonate treatment in a patient with osteoporosis.

A 76-year-old woman was treated with oral bisphosphonate, alendronate, for osteoporosis in an outpatient clinic. Routine blood tests 4 months after alendronate prescription surprisingly revealed severe hypophosphataemia. The patient was hospitalised and treated with intravenous and oral phosphate supplements. Alendronate was later reintroduced as treatment for osteoporosis and the patient once again presented with severe hypophosphataemia in subsequent routine blood tests. The patient had only presented with lower extremity pain, muscle weakness and difficulty walking. Blood tests in the emergency department both times reconfirmed severe hypophosphataemia. Plasma (p-)ionised calcium levels were normal or slightly elevated and p-parathyroid hormone levels were normal or slightly suppressed. The p-25-hydroxyvitamin-D and p-creatine were in the normal range. Critical illness, malabsorption, nutritional issues and genetics were reviewed as potential causes but considered unlikely. Phosphate levels were quickly restored each time on replacement therapy and the case was interpreted as bisphosphonate-induced severe hypophosphataemia.

Long-Term Follow-up of Hypophosphatemic Bone Disease Associated With Elemental Formula Use: Sustained Correction of Bone Disease After Formula Change or Phosphate Supplementation.

In this article, we describe the long-term outcomes of children who were previously reported to have developed hypophosphatemic bone disease in association with elemental formula use. An extended chart review allowed for an updated report of 34 children with regard to severity/duration of bone disease, extent of recovery, and time to correction using radiology reports and biochemical data. After implementation of formula change and/or phosphate supplementation, we found that serum phosphorus concentration increased and serum alkaline phosphatase activity decreased in all patients, normalizing by 6.6 ± 4.0 (mean ± SD) months following diagnosis. The decrease in serum alkaline phosphatase from diagnosis to the time of correction was moderately correlated with the concurrent increase in serum phosphorus (R = 0.48, P < .05). Age at diagnosis significantly correlated with time to resolution (R = 0.51, P = .01). This study supports the earlier report that bone disease associated with hypophosphatemia during elemental formula use responds to formula change and/or phosphate supplementation.

Interferences in the measurement of circulating phosphate: a literature review.

Background Inorganic phosphate in blood is currently determined by the reaction with molybdate. This report aims at reviewing conditions underlying spuriously altered levels of circulating inorganic phosphate. Content A systematic search of the Excerpta Medica, the National Library Database and the Web of Science database was conducted without language restriction from the earliest publication date available through January 31, 2020. Summary For the analysis, 80 reports published in English (n = 77), French (n = 1), German (n = 1) and Spanish (n = 1) were retained. Well-documented pseudohyperphosphatemia was observed in individuals exposed to liposomal amphotericin, in patients affected by a gammopathy, in patients with hyperlipidemia and in patients with hyperbilirubinemia. An unexplained elevated inorganic phosphate level sometimes provided a clue to the diagnosis of a gammopathy. Well-documented cases of pseudohypophosphatemia were observed in patients on large amounts of intravenous mannitol. Finally, pseudohypophosphatemia was occasionally observed on treatment with liposomal amphotericin and in patients with a gammopathy. Outlook In order to avoid unnecessary testing and treatment, the phenomenon of spuriously altered inorganic phosphate should be recognized. An unexplained hyperphosphatemia may provide a clue to the diagnosis of a gammopathy or a severe hyperlipidemia.

Changes in the metabolic profiles of dairy cows before and after calving that were mainly fed fodder beet (Beta vulgaris vulgaris L.) during the dry period.

Case history: Two commercial pasture-based farms within the North Canterbury district of New Zealand were feeding fodder beet (Beta vulgaris vulgaris L.) as a large proportion of the diet to cows during the dry period. On each farm 25 multiparous cows were blood sampled up to six times from 28 days before, to 21 days after calving (Day 0). Plasma samples were analysed for concentrations of ß-hydroxybutyrate (BHBA), non-esterified fatty acid (NEFA), Ca, Mg and P, and aspartate aminotransferase (AST) activity. The first sampling visit was performed when cows were being fed their maximum intake of fodder beet. Clinical findings: The mean body condition score (BCS) of cows on Farm 1 was 5.4 (95% CI = 5.3-5.6) and on Farm 2, 5.4 (95% CI = 5.3-5.6) at first sampling. Mean concentrations of BHBA increased between Days -15 and Day -8 then decreased postpartum on Day 2 before increasing again on Day 21. On Farm 2, concentrations remained low (<1.2 mmol/L) on all days of sampling. Mean concentrations of NEFA in plasma remained low during the periparturient period on Farm 1, then increased on Day 2. On Farm 2, concentrations were elevated above 0.3 mmol/L between Days -28 and -17 then decreased on Day -10, before increasing on Day 2. Mean concentrations of Ca, Mg and P were higher than threshold values on both farms prepartum. However on Day 2, there were 8/23 (35%) cows on Farm 1 and 6/23 (26%) cows on Farm 2 with concentrations of Ca in plasma <2.0 mmol/L, and 10/23 (44%) cows on Farm 1 and 8/23 (35%) cows on Farm 2 with concentrations of P in plasma <1.3 mmol/L. Mean AST activities remained relatively constant and below 130 IU/L on both farms at all sampling times. Clinical relevance: On both farms, post-partum hypocalcaemia and hypophosphataemia were common after calving despite differing fodder beet feeding and mineral supplementation regimes. There was more variation in energy status, especially prior to calving. More research is required on factors affecting mineral and energy status in dry cows fed fodder beet.

The risk of refeeding syndrome among severely malnourished tuberculosis patients in Chhattisgarh, India.

BACKGROUND: A secondary care hospital in rural India serving a highly tuberculosis (TB) and malnutrition endemic region. OBJECTIVE: In this study conducted on patients with chronic protein energy malnutrition (PEM) and TB, we sought to compare nurse-estimated vs. smartphone photograph analytic methods for assessing caloric intake and determine the incidence of refeeding hypophosphatemia (RH) and refeeding syndrome (RFS) in patients with TB. METHODS: Inpatients were prospectively enrolled. Baseline demographic, comorbidity and preadmission caloric data were collected. Nurse estimated caloric intake was compared with digital "before and after" meal images. Serum phosphorus was measured on days 1, 3 and 7 post admission. Patients with RH underwent further evaluation for RFS-associated findings. RESULTS: 27 patients were enrolled. 85% were at risk of RFS by National Institute for Health and Care Excellence (NICE) criteria. Significant discrepancy (>700 calories) was noted between nurse-estimated caloric intake compared to digital images. RH was found in 37% (10/27). None developed clinical RFS. CONCLUSIONS: Our study suggests more standardized methods of caloric intake are needed in resource-limited settings with high co-prevalence of PEM and TB. We noted that despite RH being common in inpatients with PEM+TB given high caloric diets, RFS was not detected.

Neurofibromatosis type 1 associated with hypophosphatemic osteomalacia due to hypersecretion of fibroblast growth factor 23: a case report.

BACKGROUND: Neurofibromatosis type 1 is characterized by multiple café au lait spots and cutaneous and plexiform neurofibromas, and is one of the most common autosomal dominant hereditary disorders caused by mutations of the neurofibromatosis type 1 tumor suppressor gene. Osteomalacia in neurofibromatosis type 1 is very rare and is characterized by later onset in adulthood. In humans, fibroblast growth factor 23, which is a causative factor of tumor-induced osteomalacia, is not only a paracrine and autocrine factor, but is also a physiological regulator of phosphate balance in normal serum. CASE PRESENTATION: Our patient was a 65-year-old Japanese woman whose neurofibromas began to appear when she was in elementary school. At age 28, she was diagnosed as having neurofibromatosis type 1. A spinal compression fracture and multiple rib fractures were identified in 2012 and 2017, respectively. Her laboratory findings revealed hypophosphatemia due to renal phosphate wasting and a high serum level of fibroblast growth factor 23. Neurofibromas located on the surface of her right forearm and left upper arm, in which a slight abnormal accumulation of tracers was observed on 111indium-pentetreotide scintigraphy, were surgically removed, but there was no improvement in hypophosphatemia or serum fibroblast growth factor 23 after surgery. Therefore, we administered eldecalcitol, which also failed to produce improvement in abnormal data. Subsequent combination with dibasic calcium phosphate hydrate led to improvement in some of the abnormalities, including hypophosphatemia. Immunohistochemical staining using anti-human fibroblast growth factor 23 antibody revealed slightly positive results, however, only one out of three amplifications of the fibroblast growth factor 23 gene was observed by real-time polymerase chain reaction, and no clear fibroblast growth factor 23 gene expression in the resected neurofibromas could be confirmed. CONCLUSIONS: We here describe a first rare case of a 65-year-old woman with neurofibromatosis type 1 associated with hypophosphatemic osteomalacia in which a high serum fibroblast growth factor 23 level was confirmed.

Predictors of Hypophosphatemia and Outcomes during Continuous Renal Replacement Therapy.

INTRODUCTION: Hypophosphatemia occurs in up to 80% of patients undergoing continuous renal replacement therapy (CRRT) and has been associated with poor outcomes. Whether preemptive phosphate supplementation is warranted in select patients has not been adequately explored. This single-center, retrospective cohort study evaluates predictors of hypophosphatemia and characterizes treatment approaches in adult patients undergoing at least 12 h of CRRT. METHODS: Patients were divided into 2 groups based on the presence or absence of hypophosphatemia as defined by serum phosphorus <2.5 mg/dL. Select laboratory values at baseline and during CRRT, medications and nutritional sources affecting phosphorus, and CRRT parameters were compared. Patient outcomes including resolution of acute kidney injury (AKI), freedom from renal replacement therapy at hospital discharge, duration of intensive care unit (ICU) and hospital stay, duration of mechanical ventilation, and ICU mortality were evaluated. RESULTS: Seventy-two patients were included. The group was 43% female and 51% African American. CRRT was ordered for AKI in 83% and for end-stage renal disease in 15%. Hypophosphatemia occurred in 45 patients (63%). Mean time to development of hypophosphatemia was 34 ± 22 h. Patients who developed hypophosphatemia received a longer duration of CRRT (p = 0.001), were more likely to have a diet ordered (p = 0.005), less likely to have received calcium infusions (p = 0.045), and had lower phosphorus (p = 0.017) and potassium levels (p = 0.038) and higher calcium levels at baseline (p = 0.048). Development of hypophosphatemia was associated with an increased duration of ICU stay (p = 0.014) but not with the other patient outcomes evaluated. Twenty-seven of the 45 patients (60%) who developed hypophosphatemia received phosphorus supplementation with near equal use of intravenous, oral, and combination routes. Only 17 patients (38%) achieved resolution of hypophosphatemia while on CRRT. CONCLUSION: Hypophosphatemia is common, difficult to correct, and contributes to longer ICU stays in patients requiring CRRT. A preemptive approach to address hypophosphatemia including aggressive supplementation strategies to correct phosphorus is warranted in patients requiring CRRT.