Severe hypophosphatemia in a general hospital population

Blood alcohol levels after standardized intake of alcohol are related to measured blood phosphate levels

The role of blood phosphate in alcohol metabolism has not been studied. In this explorative experimental study, the relationship between blood phosphate levels and metabolism of alcohol was investigated. Twenty young male volunteers were given alcohol relative to body weight to make them reach a theoretical blood alcohol concentration (BAC) of 0.12%. Ten measurements of BAC were taken across the time from intake, to peak and total elimination. The results indicated that individuals with high blood phosphate levels achieved a lower BAC maximum than those with low blood phosphate levels. The difference between the highest and lowest maximum BAC was as much as 30-40% and correlated negatively to physiological blood phosphate levels. The results suggest that phosphate plays a role in prehepatic, possibly gastric, alcohol metabolism. The Alcohol Dehydrogenase enzyme 7 (ADH7) is represented in the upper gastrointestinal tract and may be the enzyme responsible for this variation in the blood alcohol concentration reached.

Admission serum phosphate levels and the risk of respiratory failure

BACKGROUND

The objective of this study was to evaluate the relationship between admission serum phosphate and in-hospital respiratory failure requiring mechanical ventilation in hospitalised patients.

METHODS

We analysed a cohort of all adult patients admitted at a tertiary referral hospital between the year 2009 and 2013. We included patients who had available serum phosphate and were not on mechanical ventilation within 24 hours of hospital admission. We stratified admission serum phosphate based on its distribution into 6 groups: ≤2.4, 2.5-3.0, 3.1-3.6, 3.7-4.2, 4.3-4.8 and ≥4.9 mg/dL. We performed multivariable logistic regression analysis to assess the odds ratio of in-hospital respiratory failure requiring mechanical ventilation based on admission serum phosphate, using phosphate level of 3.1-3.6 as the reference group.

RESULTS

This study enrolled a total of 37 728 hospitalised patients, with a mean admission serum phosphate of 3.8 ± 1.1 mg/dL. Of these patients, 2792 (7.4%) developed respiratory failure requiring mechanical ventilation during hospitalisation. Increased incidence of respiratory failure requiring mechanical ventilation was observed in both decreased and increased admission serum phosphate, assuming the J-shaped curve. In adjusted analysis, admission serum phosphate of ≤2.4 and 2.5-3.0 mg/dL was significantly associated with increased risk of respiratory failure requiring mechanical ventilation with odds ratio (OR) of 1.18 (95% confidence interval [CI] 1.01-1.40) and 1.19 (95% CI 1.04-1.35), respectively. Similarly, admission serum phosphate of 4.3 to 4.8 and ≥4.9 mg/dL was significantly associated with increased risk of respiratory failure requiring mechanical ventilation with OR of 1.19 (95% CI 1.05-1.36) and 1.58 (95% CI 1.37-1.82), respectively.

CONCLUSION

Our study revealed the J-shaped association between serum phosphate level at admission and risk of respiratory failure requiring mechanical ventilation in unselected hospitalised patients.

Hypophosphatemia as a Predictor of Organ-Specific Complications Following Gastrointestinal Surgery: Analysis of 8034 Patients

BACKGROUND

Organ-specific complications (OSC) remain serious potential sequela of gastrointestinal surgery. Hypophosphatemia correlates with poor outcomes and may be a harbinger of OSC after gastrointestinal surgery. Our goal was to describe and evaluate the relationship between postoperative phosphate levels and OSC.

METHODS

Consecutive patients who underwent pancreatic, colorectal, or gastric resections were analyzed. OSC were defined as those resulting from the failure of at least one anastomosis performed during the primary resection, manifesting as an anastomotic leak, fistula, and/or intra-abdominal abscess. Postoperative serum phosphate levels and other recognized OSC risk factors were compared among patients who did and did not develop OSC.

RESULTS

A total of 8034 patients who underwent pancreatic (n = 397), colorectal (n = 5808), or gastric (n = 1829) resections were included in the study. In each resection group, the majority of patients experienced hypophosphatemia postresection with the nadir on postoperative day (POD) 2, and the subgroups that developed OSC exhibited lower phosphate levels on POD3-7. On multivariate analysis, lower phosphate level on POD3 remained significantly associated with OSC following pancreatic resection [median (interquartile range) mmol/L, 0.65 (0.53-0.76) vs. 0.71 (0.61-0.84), p = 0.045] and colorectal resection [0.71 (0.61-0.87) vs. 0.77 (0.65-0.94), p = 0.006], and lower phosphate level on POD4 remained associated with OSC following gastric resection [0.87 (0.74-1.03) vs. 0.96 (0.81-1.13), p = 0.049].

CONCLUSION

This study identified a consistent trajectory of serum phosphate levels following 3 different gastrointestinal operations and association between early postoperative phosphate levels and OSC. Persistent lower phosphate levels should raise the level of concern for evolving postoperative leak and may lead to earlier radiographic evaluation and treatment.

Successful Localization Using 68Ga-DOTATOC PET/CT of a Phosphaturic Mesenchymal Tumor Causing Osteomalacia in a Patient with Concurrent Follicular Lymphoma

Diagnosing tumor-induced osteomalacia is often challenging because conventional imaging modalities may fail to locate the responsible tumor. This report describes the ability of ⁶⁸Ga-DOTATOC PET/CT to successfully distinguish between the responsible phosphaturic mesenchymal tumor and concurrent lymphoma lesions. A 52-year-old man with bone pain for several years was diagnosed with a vitamin D-resistant hypophosphatemic osteomalacia. Whole body ¹⁸F-FDG PET/CT revealed multiple enlarged hypermetabolic lymph nodes in his bilateral cervical, axillary, mediastinal, abdominal, pelvic, and inguinal regions. Core needle biopsy of the right cervical lymph node confirmed the diagnosis of follicular lymphoma. However, lymphoma was not considered the cause of osteomalacia. ⁶⁸Ga-DOTATOC PET/CT before chemotherapy showed a small nodule with intensely increased uptake in the right inguinal region, which was distinguished from the other enlarged lymph nodes. The nodule was surgically removed and histopathologically consistent with phosphaturic mesenchymal tumor. After surgery, the patient's serum phosphorus and alkaline phosphatase levels normalized without nutritional supplement.

Admission serum phosphate levels predict hospital mortality

BACKGROUND

The aim of this study was to assess the relationship between admission serum phosphate levels and in-hospital mortality in all hospitalized patients.

METHODS

All adult hospitalized patients who had admission serum phosphate available between years 2009 and 2013 were enrolled. Admission serum phosphate was categorized based on its distribution into six groups (<2.5, 2.5-3.0, 3.1-3.6, 3.7-4.2, 4.3-4.8 and ≥4.9 mg/dL). The odds ratio (OR) of in-hospital mortality by admission serum phosphate, using the phosphate category of 3.1-3.6 mg/dL as the reference group, was obtained by logistic regression analysis.

RESULTS

42,336 patients were studied. The lowest incidence of in-hospital mortality was associated with a serum phosphate within 3.1-4.2 mg/dL. A U-shaped curve emerged demonstrating higher in-hospital mortality associated with both serum phosphate <3.1 and >4.2 mg/dL. After adjusting for potential confounders, both serum phosphate <2.5 and >4.2 mg/dL were associated with in-hospital mortality with ORs of 1.60 (95%CI 1.25-2.05), 1.60 (95%CI 1.29-1.97), and 3.89 (95%CI 3.20-4.74) when serum phosphate were <2.5, 4.3-4.8 and ≥4.9 mg/dL, respectively. Among subgroups of patients with chronic kidney disease (CKD) and cardiovascular disease (CVD), the highest mortality was associated with a serum phosphate ≥4.9 mg/dL with ORs of 4.11 (95%CI 3.16-5.39) in CKD patients and 5.11 (95%CI 3.33-7.95) in CVD patients.

CONCLUSION

Hospitalized patients with admission serum phosphate <2.5 and >4.2 mg/dL are associated with an increased risk of in-hospital mortality. The highest mortality risk is associated with CKD and CVD patients with admission hyperphosphatemia.

Hyperphosphatemia Is an Independent Risk Factor for Mortality in Critically Ill Patients: Results from a Cross-Sectional Study

BACKGROUND

Phosphate imbalances or disorders have a high risk of morbidity and mortality in patients with chronic kidney disease. It is unknown if this finding extends to mortality in patients presenting at an emergency room with or without normal kidney function.

METHODS AND PATIENTS

This cross sectional analysis included all emergency room patients between 2010 and 2011 at the Inselspital Bern, Switzerland. A multivariable cox regression model was applied to assess the association between phosphate levels and in-hospital mortality up to 28 days.

RESULTS

22,239 subjects were screened for the study. Plasma phosphate concentrations were measured in 2,390 patients on hospital admission and were included in the analysis. 3.5% of the 480 patients with hypophosphatemia and 10.7% of the 215 patients with hyperphosphatemia died. In univariate analysis, phosphate levels were associated with mortality, age, diuretic therapy and kidney function (all p<0.001). In a multivariate Cox regression model, hyperphosphatemia (OR 3.29, p<0.001) was a strong independent risk factor for mortality. Hypophosphatemia was not associated with mortality (p>0.05).

CONCLUSION

Hyperphosphatemia is associated with 28-day in-hospital mortality in an unselected cohort of patients presenting in an emergency room.

Phosphate homeostasis and disorders

Recent studies of inherited disorders of phosphate metabolism have shed new light on the understanding of phosphate metabolism. Phosphate has important functions in the body and several mechanisms have evolved to regulate phosphate balance including vitamin D, parathyroid hormone and phosphatonins such as fibroblast growth factor-23 (FGF23). Disorders of phosphate homeostasis leading to hypo- and hyperphosphataemia are common and have clinical and biochemical consequences. Notably, recent studies have linked hyperphosphataemia with an increased risk of cardiovascular disease. This review outlines the recent advances in the understanding of phosphate homeostasis and describes the causes, investigation and management of hypo- and hyperphosphataemia.

Occurrence of refeeding syndrome in adults started on artificial nutrition support: prospective cohort study

BACKGROUND

Refeeding syndrome is a potentially life-threatening condition characterised by severe intracellular electrolyte shifts, acute circulatory fluid overload and organ failure. The initial symptoms are non-specific but early clinical features are severely low-serum electrolyte concentrations of potassium, phosphate or magnesium. Risk factors for the syndrome include starvation, chronic alcoholism, anorexia nervosa and surgical interventions that require lengthy periods of fasting. The causes of the refeeding syndrome are excess or unbalanced enteral, parenteral or oral nutritional intake. Prevention of the syndrome includes identification of individuals at risk, controlled hypocaloric nutritional intake and supplementary electrolyte replacement.

OBJECTIVE

To determine the occurrence of refeeding syndrome in adults commenced on artificial nutrition support.

DESIGN

Prospective cohort study.

SETTING

Large, single site university teaching hospital. Recruitment period 2007-2009.

PARTICIPANTS

243 adults started on artificial nutrition support for the first time during that admission recruited from wards and intensive care.

MAIN OUTCOME MEASURES

PRIMARY OUTCOME

occurrence of the refeeding syndrome. Secondary outcome: analysis of the risk factors which predict the refeeding syndrome. Tertiary outcome: mortality due to refeeding syndrome and all-cause mortality.

RESULTS

133 participants had one or more of the following risk factors: body mass index <16-18.5≥(kg/m(2)), unintentional weight loss >15% in the preceding 3-6 months, very little or no nutritional intake >10 days, history of alcohol or drug abuse and low baseline levels of serum potassium, phosphate or magnesium prior to recruitment. Poor nutritional intake for more than 10 days, weight loss >15% prior to recruitment and low-serum magnesium level at baseline predicted the refeeding syndrome with a sensitivity of 66.7%: specificity was >80% apart from weight loss of >15% which was 59.1%. Baseline low-serum magnesium was an independent predictor of the refeeding syndrome (p=0.021). Three participants (2% 3/243) developed severe electrolyte shifts, acute circulatory fluid overload and disturbance to organ function following artificial nutrition support and were diagnosed with refeeding syndrome. There were no deaths attributable to the refeeding syndrome, but (5.3% 13/243) participants died during the feeding period and (28% 68/243) died during hospital admission. Death of these participants was due to cerebrovascular accident, traumatic injury, respiratory failure, organ failure or end-of-life causes.

CONCLUSIONS

Refeeding syndrome was a rare, survivable phenomenon that occurred during hypocaloric nutrition support in participants identified at risk. Independent predictors for refeeding syndrome were starvation and baseline low-serum magnesium concentration. Intravenous carbohydrate infusion prior to artificial nutrition support may have precipitated the onset of the syndrome.

Metabolic encephalopathies

Kinnier Wilson coined the term metabolic encephalopathy to describe a clinical state of global cerebral dysfunction induced by systemic stress that can vary in clinical presentation from mild executive dysfunction to deep coma with decerebrate posturing; the causes are numerous. Some mechanisms by which cerebral dysfunction occurs in metabolic encephalopathies include focal or global cerebral edema, alterations in transmitter function, the accumulation of uncleared toxic metabolites, postcapillary venule vasogenic edema, and energy failure. This article focuses on common causes of metabolic encephalopathy, and reviews common causes, clinical presentations and, where relevant, management.

Treatment of hypophosphatemia in the intensive care unit: a review

Introduction

Currently no evidence-based guideline exists for the approach to hypophosphatemia in critically ill patients.

Methods

We performed a narrative review of the medical literature to identify the incidence, symptoms, and treatment of hypophosphatemia in critically ill patients. Specifically, we searched for answers to the questions whether correction of hypophosphatemia is associated with improved outcome, and whether a certain treatment strategy is superior.

Results

Incidence: hypophosphatemia is frequently encountered in the intensive care unit; and critically ill patients are at increased risk for developing hypophosphatemia due to the presence of multiple causal factors. Symptoms: hypophosphatemia may lead to a multitude of symptoms, including cardiac and respiratory failure. Treatment: hypophosphatemia is generally corrected when it is symptomatic or severe. However, although multiple studies confirm the efficacy and safety of intravenous phosphate administration, it remains uncertain when and how to correct hypophosphatemia. Outcome: in some studies, hypophosphatemia was associated with higher mortality; a paucity of randomized controlled evidence exists for whether correction of hypophosphatemia improves the outcome in critically ill patients.

Conclusions

Additional studies addressing the current approach to hypophosphatemia in critically ill patients are required. Studies should focus on the association between hypophosphatemia and morbidity and/or mortality, as well as the effect of correction of this electrolyte disorder.

Hypophosphataemia: An Easy Strategy for Diagnosis and Treatment in HIV Patients

Because HIV infection has become a chronic disease, it is crucial that metabolic complications secondary to HIV infection or prolonged therapy be diagnosed and managed appropriately over time. Therefore the optimal follow-up becomes complex and time consuming. Our review aimed to provide physicians in charge of HIV-infected patients with key data helping them to diagnose and understand hypophosphataemia in HIV patients. Hypophosphataemia is frequent and sometimes secondary to renal phosphate wasting. It is very rarely a component of a complex proximal tubular disorder, such as Fanconi syndrome. When isolated, hypophosphataemia is easy to rule out and treat. In rare cases, prolonged hypophosphataemia, when related to renal phosphate wasting and tubular dysfunction, might have potential consequences on bone outcome, however, more studies are needed. HIV infection by itself might be a risk factor for bone metabolism abnormalities; antiretroviral drugs might also be involved. Therefore, it seems valuable for patients that the minimal screening should be performed routinely, in order to prevent long-term disabilities.

Electrolyte disorders related to EGFR-targeting drugs

It is now clearly established that anti-vascular endothelial growth factor (VEGF) drug class induces hypertension and proteinuria sometimes related to thrombotic microangiopathy and/or various glomerulopathies, according to capillary and glomerular VEGF and VEGF-receptor expressions. As reported in the literature, anti-epidermal growth factor receptor (EGFR) therapies seem to be less nephrotoxic. Indeed, many reports of anti-EGFR nephrotoxicity are tubular dependent such as acute tubular necrosis, electrolyte disorders (hypophosphatemia, hypomagnesemia, etc.) or both. This is explained by elective tubular expression of renal EGF/EGFR. In this paper, we focus on electrolyte disorders related to anti-EGFR treatment and discuss the tubular involvement of these drugs based on their renal expression.

Hypophosphataemia at a large academic hospital in South Africa

Aim:

The aim of this study was to determine the most common causes of hypophosphataemia (⩽0.5 mmol/l) in a hospital population in order to identify patient groups at risk of developing the condition.

Methods:

The study was conducted at Tygerberg Hospital, a tertiary care centre in the Western Cape, South Africa. All patients identified with a phosphate level ⩽0.5 mmol/l during an 18-month period were included in the study. Medical records of these patients were reviewed.

Results:

Of all the requests received for serum phosphate determination by the laboratory, 2% (861 out of 45 394 requests) were ⩽0.5 mmol/l. Thirty per cent (30%; n = 189) of the patients in the study population died during their hospital stay. Most (45%; n = 278) of the patients with low phosphate levels occurred in an intensive care setting, whereas 10% (n = 63) were most likely due to refeeding, and 6% (n = 35) had neoplastic disease. Sepsis was implicated as a contributing factor in 26% (n = 162).

Conclusion:

Severe hypophosphataemia is associated with a very high mortality (30%, n = 189). Patients with a high risk of developing hypophosphataemia include those in an intensive care unit (ICU), patients suffering from neoplastic diseases, possible refeeding syndrome and septic patients. Regular phosphate determination is recommended in these patients to facilitate early diagnosis of hypophosphataemia.

Potassium and phosphorus repletion in hospitalized patients: implications for clinical practice and the potential use of healthcare information technology to improve prescribing and patient safety

OBJECTIVES

Evaluate potassium and phosphorus repletion in hospitalized patients. Assess the potential role for use of various methods, including healthcare information technology, to improve prescribing and patient safety.

RESEARCH DESIGN AND METHODS

Inpatient medication profiles were screened to identify orders for potassium and phosphorus replacement products. Electronic laboratory and medical records were used to evaluate efficacy and safety. Eligibility for oral therapy was defined by the presence of other scheduled oral medications on the medication profile. Appropriateness of prescribing was based on adherence to the hospital guidelines for repletion.

RESULTS

Overall, 134 orders for potassium in 92 patients and 36 orders for phosphorus in 27 patients were evaluated over a 3-week data collection period. Intravenous (IV) potassium was prescribed in 73% of replacement episodes (46% as single doses and 54% within large volume IV fluids), with 85% for normokalemia or mild-to-moderate cases of hypokalemia. Phosphorus orders involved single doses of IV potassium phosphate (mean 13.1 mmol) in 75% of cases. Approximately 85% of doses were for mild or moderate hypophosphatemia. Eligibility for oral therapy was evident in 74% of normokalemic or mild hypokalemic cases receiving IV potassium products and in 33% of cases receiving IV phosphorus replacement. Six cases of mild hyperkalemia were observed. No hyperphosphatemia was documented. Study limitations include use of a retrospective design, inability to discern whether some electrolyte doses were given with a preventative intent, potential overestimation of the number of patients eligible for oral repletion, and lack of data on the accessibility of the laboratory serum concentrations or the awareness of serum values to the prescribers.

CONCLUSIONS

Intravenous potassium and phosphate products are commonly prescribed for mild or moderate cases of hypokalemia or hypophosphatemia. Many patients met eligibility for oral therapy. Efforts to enhance prescriber education and implement computerized prescribing and decision support systems have the potential to improve prescribing and reduce possibilities of adverse drug events and medication errors related to potassium and phosphate administration.

Hypophosphatemia: an update on its etiology and treatment

Phosphate plays a key role in several biological processes. In recent years, new insights have been obtained into the regulation of the phosphate metabolism, including a growing amount of evidence suggesting that factors other than parathyroid hormone (PTH) and vitamin D are involved in maintaining the phosphate balance. A new class of phosphate-regulating factors, the so-called "phosphatonins," have been shown to be important in phosphate-wasting diseases. However, the role of the phosphatonins in the normal human homeostasis remains to be established. The incidence of hypophosphatemia in selected patient series can be more than 20%, with clinical sequelae ranging from mild to life threatening. Only when combined with phosphate depletion does hypophosphatemia become clinically significant. The factors that are involved in the phosphate homeostasis, the pathophysiology, the relevance in patient care, the clinical manifestations, and an appropriate management of phosphate depletion are discussed in this review.

Is hypotonic dysfunctional labor associated with hypophosphatemia?

OBJECTIVE

The purpose of this study was to determine whether hypotonic dysfunctional labor is associated with hypophosphatemia.

STUDY DESIGN

We conducted a prospective nested case control study of term women who were in active labor. Serum phosphate samples were drawn at admission with active labor and before delivery. Phosphate concentration was compared between control subjects and women with hypotonic, dysfunctional uterine contractions.

RESULTS

Both serum samples were available for 90 women. Hypophosphatemia was documented in 14% of the participants. There was no significant difference in phosphate concentration between the 2 groups either at admission or before delivery. The mean decrease in phosphate concentration between admission and delivery was similar between the 2 cohorts.

CONCLUSION

Although transient hypophosphatemia is found commonly in laboring women, hypotonic dysfunctional contractions are not associated with mild hypophosphatemia.

High prevalence of hypophosphataemia amongst patients with infectious diseases. A retrospective study

OBJECTIVES

To describe the prevalence of hypophosphataemia amongst all patients treated during 1993 for infectious diseases. The associations between serum C-reactive protein, serum albumin and white blood cells in blood were studied amongst hypophosphataemic patients. Comparisons were made according to the severity of infection.

DESIGN

A retrospective study of the prevalence of hypophosphataemia, and a case-control study amongst a subgroup of patients.

SETTING

The Department of Infectious Diseases, University Hospital, Umeå, Sweden.

SUBJECTS

For the prevalence study all 967 patients (449 women and 518 men) treated during 1993 were included. In the case-control study, 108 cases, with serum phosphate < or =0.64 mmol L(-1), 216 age-and sex-matched controls with serum phosphate >0.82 mmol L(-1) (men) and >0.86 mmol L(-1) (women), respectively, were included.

RESULTS

In 402 of 967 patients (42%) at least one serum phosphate value was below the reference level. Hypophosphataemia was found in 573 of 1966 blood samples (29%). Severe hypophosphataemia (<0.30 mmol L(-1)) was seen in 1.2% of the patients (0.9% of blood samples). The prevalence of hypophosphataemia was higher amongst women than amongst men. In the case-control study, the serum C-reactive protein and the number of white blood cells was higher amongst the cases compared with the controls (124 vs. 94 mg L(-1) and 11.4 vs. 9.3 cells/L x10(9), respectively). The multiple logistic regression showed a 4-fold higher risk of having low serum phosphate in patients with severe infection, compared with mild infections. None of the other variables (albumin, days of hospital stay or white blood cells in blood) increased the risk for hypophosphataemia.

CONCLUSIONS

The high prevalence of low serum phosphate levels and the increased risk of having low levels in severe infections shown in this study needs further attention.

Hypophosphataemia in general practice patients

We compared plasma phosphate concentrations in general practice patients and hospital inpatients and outpatients over an 8-month period. The distribution of results in all three groups was similar and 12-16% of results were at or below 0.8 mmol/L. In general practice patients, 8.3% of results from males and 12.1% from females were below the lower limit of their respective reference ranges. Eighteen of these patients (0.2% of results) had plasma phosphate concentrations < or = 0.4 mmol/L. On follow-up, only two of these patients had any attributable cause for their severe hypophosphataemia; in the remainder, it was unexpected and unexplained. Hypophosphataemia in outpatients and general practice patients is more common than has previously been appreciated. We present a strategy for further investigation of these patients.

Magnesium and phosphorus

A summary of new findings regarding alterations of magnesium (Mg2+) and phosphorus (P) metabolism are reviewed for the clinician caring for patients in general wards. Alterations in serum concentrations of Mg2+ and P are frequently observed in acute or very ill patients in emergency rooms or intensive-care areas. A significant proportion of these alterations are iatrogenic. Most of the symptoms related are non-specific, and usually they are associated with changes in concentration of other ions. The need to measure Mg2+ and P routinely and to define better the real abnormal values is stressed. Correction of the abnormalities must be early in the course of the alterations.

Hypophosphatemia-induced neuropathy: clinical and electrophysiologic findings

Severe hypophosphatemia has rarely been reported as a cause of acute paralysis. We present the clinical and electrophysiological findings on a patient who developed quadriparesis following several surgeries for complicated cholecystectomy. The paralysis was most likely the result of severe hypophosphatemia causing a neuropathy which improved readily after proper phosphate replacement. The possible pathogenic mechanisms of hypophosphatemic neuropathy are discussed.

Severe hypophosphatemia in postoperative patients

Severe hypophosphatemia may develop in postoperative patients for several reasons including alcohol withdrawal, diabetic ketoacidosis, nutritional recovery (refeeding) syndrome, and severe respiratory alkalosis. Severe hypophosphatemia may result in central nervous system abnormalities, muscle weakness, and renal, hepatic, cardiac, and respiratory dysfunction. Hypophosphatemia may be prevented by close monitoring of phosphorus concentrations in serum, especially in patients predisposed to developing this problem. Proper techniques for the maintenance and repletion of phosphate for both enteral and parenteral use are described.