Hemodynamic and metabolic effects of rapid correction of hypophosphatemia in patients with septic shock

Intensive Care Unit-Acquired Weakness in Patients With Acute Kidney Injury: A Contemporary Review

Acute kidney injury (AKI) and intensive care unit-acquired weakness (ICU-AW) are 2 frequent complications of critical illness that, until recently, have been considered unrelated processes. The adverse impact of AKI on ICU mortality is clear, but its relationship with muscle weakness-a major source of ICU morbidity-has not been fully elucidated. Furthermore, improving ICU survival rates have refocused the field of intensive care toward improving long-term functional outcomes of ICU survivors. We begin our review with the epidemiology of AKI in the ICU and of ICU-AW, highlighting emerging data suggesting that AKI and AKI treated with kidney replacement therapy (AKI-KRT) may independently contribute to the development of ICU-AW. We then delve into human and animal data exploring the pathophysiologic mechanisms linking AKI and acute KRT to muscle wasting, including altered amino acid and protein metabolism, inflammatory signaling, and deleterious removal of micronutrients by KRT. We next discuss the currently available interventions that may mitigate the risk of ICU-AW in patients with AKI and AKI-KRT. We conclude that additional studies are needed to better characterize the epidemiologic and pathophysiologic relationship between AKI, AKI-KRT, and ICU-AW and to prospectively test interventions to improve the long-term functional status and quality of life of AKI survivors.

Clinical value of serum calcium in elderly patients with sepsis

PURPOSE

To explore the clinical value of serum calcium (Ca) in elderly patients with sepsis.

MATERIALS AND METHODS

The clinical data and laboratory data of elderly patients with sepsis (n = 165) and elderly population for physical examination (n = 67) in a tertiary hospital from January 2020 to November 2020 were collected. We analyzed serum Ca levels in sepsis and septic shock firstly, and then continued to investigate them in the survival group and the death group. Meanwhile, we also assessed the correlation between serum Ca and PCT.

RESULTS

The serum Ca levels of the elderly patients with sepsis were lower than that of the control group (median 1.98 vs 2.31 mmol/L, P < 0.001), and the more severe the sepsis, the lower the serum Ca levels. Sepsis patients with decreased serum Ca had higher shock rate and mortality. There was a negative correlation between serum Ca and PCT (r = -0.2957, P < 0.001).

CONCLUSION

Serum Ca has a certain value for the early recognition of elderly patients with sepsis and the judgment of the severity of the disease.

[Prescription of phosphorus, calcium and magnesium: choice of the millimole unit to establish the equivalence of doses between oral and injectable forms]

OBJECTIVES

Information available on the packaging of drugs indicated for patients electrolytes replenishment differs from one manufacturer to another. They relate, for example, the unit chosen to express elemental electrolyte concentration. These differences constitute a risk factor for medication errors. This article proposes a clinical decision support tool which defines dose equivalences between the oral and injectable formulation galenic forms for medications providing phosphorus, calcium and magnesium and a calculated replenishment ratio.

METHODS

The amounts of elemental electrolyte were determined from the information contained on the packaging and the summaries of product characteristics. Only the specialties of our hospital drug formulary were studied. For each element, the replenishment ratio was determined from published data.

RESULTS

Equivalence tables were created for the phosphorus, calcium and magnesium between oral and injectable formulation. A clinical decision support tool was developed from these data.

CONCLUSION

The use of this tool is a first way to reduce the risk of medication errors. It remains to determine the conditions for its dissemination and evaluation. This issue raises the questions of the exclusive use of the millimole unit on packaging and for prescription, and that of the integration of this type of tool into prescription software and decision support systems.

Impaired cardiac and neurological function with mild hypophosphatemia during insulin therapy for diabetic ketoacidosis and marked improvement with phosphate supplementation: A case report

Insulin treatment for diabetic ketoacidosis occasionally results in hypophosphatemia, which is often mild and does not require treatment. However, we experienced a case in which intravenous insulin administration resulted in myocardial injury and altered consciousness despite mild hypophosphatemia. Phosphate replacement therapy resulted in a marked improvement in symptoms. As overlapping conditions that result in hypophosphatemia can cause severe complications after insulin therapy for diabetic ketoacidosis, even in patients with mild hypophosphatemia, physicians should pay more attention to changes in phosphate levels in patients undergoing treatment for diabetic ketoacidosis.

Hypophosphatemia in critically ill adults and children - A systematic review

BACKGROUND & AIMS

Phosphate is the main intracellular anion essential for numerous biological processes. Symptoms of hypophosphatemia are non-specific, yet potentially life-threatening. This systematic review process was initiated to gain a global insight into hypophosphatemia, associated morbidity and treatments.

METHODS

A systematic review was conducted (PROSPERO CRD42020163191). Nine clinically relevant questions were generated, seven for adult and two for pediatric critically ill patients, and prevalence of hypophosphatemia was assessed in both groups. We identified trials through systematic searches of Medline, EMBASE, Scopus, Cochrane Central Register of Controlled Trials, CINAHL, and Web of Science. Quality assessment was performed using the Cochrane risk of bias tool for randomized controlled trials and the Newcastle-Ottawa Scale for observational studies.

RESULTS

For all research questions, we identified 2727 titles in total, assessed 399 full texts, and retained 82 full texts for evidence synthesis, with 20 of them identified for several research questions. Only 3 randomized controlled trials were identified with two of them published only in abstract form, as well as 28 prospective and 31 retrospective studies, and 20 case reports. Relevant risk of bias regarding selection and comparability was identified for most of the studies. No meta-analysis could be performed. The prevalence of hypophosphatemia varied substantially in critically ill adults and children, but no study assessed consecutive admissions to intensive care. In both critically ill adults and children, several studies report that hypophosphatemia is associated with worse outcome (prolonged length of stay and the need for respiratory support, and higher mortality). However, there was insufficient evidence regarding the optimal threshold upon which hypophosphatemia becomes critical and requires treatment. We found no studies regarding the optimal frequency of phosphate measurements, and regarding the time window to correct hypophosphatemia. In adults, nutrient restriction on top of phosphate repletion in patients with refeeding syndrome may improve survival, although evidence is weak.

CONCLUSIONS

Evidence on the definition, outcome and treatment of clinically relevant hypophosphatemia in critically ill adults and children is scarce and does not allow answering clinically relevant questions. High quality clinical research is crucial for the development of respective guidelines.

Impact of electrolyte-rich dialysate during continuous renal replacement therapy on serum phosphate and potassium in ICU patients

Background

Hypophosphatemia and hypokalemia occur frequently during continuous renal replacement therapy (CRRT). We evaluated serum phosphate and potassium levels in patients administered three different types of dialysis solution.

Methods

The study population consisted of 324 intensive care unit patients who underwent CRRT between January 2015 and December 2018. Patients were divided into three groups: group 1 (n = 105) received Hemosol B0 (no potassium or phosphate); group 2 (n = 78) received Hemosol B0 and potassium-containing solution (MultiBic); and group 3 (n = 141) received phosphate- and potassium-containing solution (Phoxilium), Hemosol B2, Prismasol 2, and Prismasol 4. A different protocol was followed in each group.

Results

The incidence rate of hypophosphatemia was 55% lower in group 3 compared to group 1 (incidence rate ratio (IRR) 0.45, 95% confidence interval (CI): 0.33 to 0.61) and 61% lower compared to group 2 (IRR 0.39, 95% CI: 0.29 to 0.53). Group 3 also had a 50% lower incidence rate of hypokalemia compared to group 1 (IRR 0.50, 95% CI: 0.29 to 0.88). The negative slope in phosphate level in group 3 was greater than that in group 1 (ß = 0.19, 95% CI: 0.02 to 0.37, p = 0.032), while the negative slope in the potassium level was greater in group 2 than in group 1(ß = 0.10, 95% CI: 0.03 to 0.17, p = 0.008). Additional intravenous calcium was not used in any case, and most cases of acid-base disturbances were well controlled.

Conclusions

The use of phosphate- and potassium-containing with a proper CRRT protocol prevented decreases in serum phosphate and potassium levels, thus also preventing hypophosphatemia and hypokalemia, and additional replacement during CRRT.

Hypophosphatemia in critically ill patients with acute kidney injury on renal replacement therapies

Hypophosphatemia is a common but often underestimated electrolyte derangement among intensive care unit (ICU) patients. Low phosphate levels can lead to cellular dysfunction with potentially relevant clinical manifestations (e.g., muscle weakness, respiratory failure, lethargy, confusion, arrhythmias). In critically ill patients with severe acute kidney injury (AKI) renal replacement therapies (RRTs) represent a well-known risk factor for hypophosphatemia, especially if the most intensive and prolonged modalities of RRT, such as continuous RRT or prolonged intermittent RRT, are used. Currently, no evidence-based specific guidelines are available for the treatment of hypophosphatemia in the critically ill; however, considering the potentially negative impact of hypophosphatemia on morbidity and mortality, strategies aimed at reducing its incidence and severity should be timely implemented in the ICUs. In the clinical setting of critically ill patients on RRT, the most appropriate strategy could be to anticipate the onset of RRT-related hypophosphatemia by implementing the use of phosphate-containing solutions for RRT through specifically designed protocols. The present review is aimed at summarizing the most relevant evidence concerning epidemiology, prognostic impact, prevention and treatment of hypophosphatemia in critically ill patients with AKI on RRT, with a specific focus on RRT-induced hypophosphatemia.

Hypophosphataemia in confused half-marathon runners: A report of two cases

Introduction:

Severe hypophosphataemia may occur in long distance runners presenting to Accident & Emergency (A&E) department with exertional heat illness.

Case presentation:

A 46-year-old man who collapsed in half marathon race was found to have raised body temperature (38.8°C) and confused with memory loss in the Accident & Emergency department. His amnesia was persistent even after his body temperature was normalized. He was found to have severe hypophosphataemia (0.21 mmol/L; reference range: 0.74 - 1.4 mmol/L). He had a neurological recovery after phosphate replacement. Another 45-year-old female half marathon runner was found to have moderate hypophosphataemia (0.5 mmol/L) co-presenting with exertional heat illness.

Discussion:

Moderate to severe hypophosphataemia complicated the clinical picture of the two cases presented with exertional heat illness. Causes of hypophosphataemia in runners are multifactorial.

Conclusion:

Emergency physician should be alert of profound hypophosphataemia as a complication in heat exertional illness.

Aggressive Treatment of Life-Threatening Hypophosphatemia During Recovery From Fulminant Hepatic Failure: A Case Report

Acute liver failure secondary to acetaminophen overdose can be a life-threatening condition, characterized by severe electrolyte derangements. Hepatocyte regeneration is associated with phosphorous utilization and is a known complication of liver recovery following injury. We report the case of profound, life-threatening hypophosphatemia following recovery from acute fulminant liver failure. As the liver enzymes normalized, serum phosphorous levels plummeted. Our patient required an aggressive, individualized phosphorus replacement regimen, which resulted in a continuous infusion of intravenous (IV) sodium phosphate, titrated to a maximum rate of 30 mmol/h or 0.5 mmol/kg/h. The patient required over 400 mmol of total IV and oral phosphorous over the course of 48 hours. An aggressive approach to phosphorous replacement was done safely and effectively. Traditional replacement protocols are not adequate to sustain patients with this degree of hypophosphatemia. This is the first report to utilize a continuous infusion of phosphate with a maximum reported rate (0.5 mmol/kg/h). Our report summarizes a novel and safe approach for clinicians to maximally support these patients through high-dose, continuous infusion phosphorous administration.

[Causes, consequences and treatment of hypophosphatemia: A systematic review]

CONTEXT

Although hypophosphatemia is usually very seldom, it can reach two to 3% of hospitalized patients and until 28% of intensive care unit patients. Due to the lack of knowledge, clinical practice regarding seeking or treatment of hypophosphatemia is very heterogenous. However its clinical consequences might be heavy. A better knowledge of its causes, physiopathological effects and treatment should lead to a documented and homogenous care of these patients in clinics.

OBJECTIVE

The aim of our study was a systematic review of littérature, seeking for publications about causes, consequences and treatment of hypophosphatemia.

DOCUMENTARY SOURCES (KEYWORDS AND LANGUAGE)

A research has been conducted on the Medline database by using the following keywords "phosphorus supplementation", "hypophosphatemia" and ("physiopathology" or "complications").

RESULTS

Three mains mechanisms might be responsible for hypophosphatemia: a decrease in digestive absorption, a rise in kidney excretion and a transfer of phosphorus to the intracellular compartment. Denutrition, acid base balance troubles, parenteral nutrition or several drugs are capable of provoking or favouring hypophosphatemia. All these situations are frequently encountered in intensive care unit. Consequences of hypophosphatemia might be serious. Best studied and documented are cardiac and respiratory muscle contractility decrease, sometimes leading to acute cardiac and respiratory failure, cardiac rhythm troubles and cardiac arrest. Hypophosphatemia is frequent during sepsis. It could be responsible for leucocyte dysfunction that might favour or increase sepsis. The treatment of hypophosphatemia is usually simple through a supplementation that quickly restores a regular concentration, with few adverse effects when regularly used.

CONCLUSION

During at-risk situations, the systematic search for hypophosphatemia and its treatment may limit the occurrence of serious consequences.

A New Graduated Dosing Regimen for Phosphorus Replacement in Patients Receiving Nutrition Support

BACKGROUND

Hypophosphatemia is a common metabolic complication in patients receiving specialized nutrition support. We changed our previously reported dosing algorithm because the low dose no longer appeared to be effective at increasing serum phosphorus concentrations. The purpose of this study was to evaluate the safety and efficacy of a revised weight-based phosphorus-dosing algorithm in critically ill trauma patients receiving specialized nutrition support.

METHODS

Seventy-nine adult trauma patients with hypophosphatemia (serum phosphorus concentration < or = 0.96 mmol/L) receiving nutrition support received an IV dose of phosphorus on day 1 according to the serum concentration of phosphorus: 0.73-0.96 mmol/L (0.32 mmol/kg, low dose), 0.51-0.72 mmol/L (0.64 mmol/kg, moderate dose), and < or = 0.5 mmol/L (1 mmol/kg, high dose). The IV phosphorus bolus dose was administered at 7.5 mmol/hour. Generally, patients with a serum potassium concentration <4 mmol/L received potassium phosphate and patients with a serum potassium concentration > or = 4 mmol/L received sodium phosphate. Patients who still had hypophosphatemia on day 2 were dosed using the new dosing algorithm by the nutrition support service according to that day's serum concentration of phosphorus, or empirically by the trauma service.

RESULTS

Of the 79 patients studied, 57 were male and 22 were female with a mean age of 44.8 +/- 20.6 years. Mean Injury Severity Scores and APACHE-II scores were 27.1 +/- 11.6 and 15.2 +/- 6.8, respectively. There was no difference in baseline characteristics among the 3 dosing groups. Of the 79 patients, 34 received the low dose, 30 received the moderate dose, and 15 received the high dose of phosphorous. Mean serum phosphorous concentrations on day 2 were significantly increased in the moderate-dosed group (0.64 +/- 0.06 to 0.77 +/- 0.22 mmol/L, p < .05) and high-dosed group (0.38 +/- 0.06 to 0.93 +/- 0.32 mmol/L, p < .01), respectively, when compared with day 1. Mean serum phosphorus concentrations were normal in all 3 groups on day 3. Serum concentrations of magnesium, sodium, and potassium, as well as arterial pH, were stable across the study. Mean concentrations of ionized calcium were not significantly different in any of the 3 dosing groups across the study period.

CONCLUSIONS

This weight-based phosphorus-dosing algorithm is safe for use in critically ill patients receiving nutrition support. The moderate and severe-dose regimens effectively increase serum phosphorus concentrations.

Electrolyte and mineral disturbances in septic acute kidney injury patients undergoing continuous renal replacement therapy

Electrolyte and mineral disturbances remain a major concern in patients undergoing continuous renal replacement therapy (CRRT); however, it is not clear whether those imbalances are associated with adverse outcomes in patients with septic acute kidney injury (AKI) undergoing CRRT. We conducted a post-hoc analysis of data from a prospective randomized controlled trial. A total of 210 patients with a mean age of 62.2 years (136 [64.8%] males) in 2 hospitals were enrolled. Levels of sodium, potassium, calcium, and phosphate measured before (0 hour) and 24 hours after CRRT initiation. Before starting CRRT, at least 1 deficiency and excess in electrolytes or minerals were observed in 126 (60.0%) and 188 (67.6%) patients, respectively. The excess in these parameters was greatly improved, whereas hypokalemia and hypophosphatemia became more prevalent at 24 hours after CRRT. However, 1 and 2 or more deficiencies in those parameters at the 2 time points were not associated with mortality. However, during 28 days, 89 (71.2%) deaths occurred in patients with phosphate levels at 0 hour of ≥4.5 mg/dL as compared with 49 (57.6%) in patients with phosphate levels <4.5 mg/dL. The 90-day mortality was also significantly higher in patients with hyperphosphatemia. Similarly, in 184 patients who survived at 24 hours after CRRT, hyperphosphatemia conferred a 2.2-fold and 2.6-fold increased risk of 28- and 90-day mortality, respectively. The results remained unaltered when the serum phosphate level was analyzed as a continuous variable. Electrolyte and mineral disturbances are common, and hyperphosphatemia may predict poor prognosis in septic AKI patients undergoing CRRT.

Neuromuscular signs associated with acute hypophosphatemia in a dog

The purpose of this report was to describe the successful recognition and management of neuromuscular dysfunction secondary to severe, acute hypophosphatemia in an adult dog with a 2 day history of vomiting, anorexia, and abdominal pain. Radiographs were suggestive of a foreign body obstruction, and surgery was recommended. Resection and anastomosis of the distal duodenum and proximal jejunum was performed. The dog recovered uneventfully, but approximately 36 hr postoperatively, he was found to have significant weakness and muscle tremors that were accompanied by hyperthermia. The only significant abnormality on a serum biochemical profile was a phosphorous level of 0.26 mmol/L. Within 6 hr of initiating phosphorous supplementation, the patient fully recovered and had no residual signs of neuromuscular dysfunction. Signs of neurologic dysfunction secondary to hypophosphatemia are commonly recognized in human patients. Reports of patients with severe muscle weakness, some of which necessitate ventilation due to weakening of muscles of respiration, are common throughout the literature. Less commonly, tremors are noted. This is the first known report of neuromuscular signs recognized and rapidly corrected in a dog. Although it is likely to be uncommon, hypophosphatemia should be recognized as a differential diagnosis in patients with tremors and/or muscle weakness.

Prevalence of severe hypokalaemia in patients with traumatic brain injury

INTRODUCTION

Patients with traumatic brain injury (TBI) are more vulnerable to develop hypokalaemia, we sought to investigate the prevalence, and the relationship between severe hypokalaemia and the mortality of traumatic brain injury patients.

METHODS

Isolated traumatic brain patients who had hypokalaemia (serum potassium <3.5mmol/L) and age≥14yrs were recruited into the study between January 2008 and March 2013. Hypokalaemia was defined as potassium level in the blood <3.5mmol/L during the hospitalisation, which was classified by severity: mild (3.0mmol/L≤K<3.5mmol/L), moderate (2.5mmol/L≤K<3.0mmol/L) and severe (K<2.5mmol/L). Multivariable logistic regression was performed to find the impact of hypokalaemia on mortality.

RESULTS

A total 375 cases were included in analysis. The peak incidence of severe hypokalaemia occurred in the first 24-96h. TBI patients with severe hypokalaemia had significantly higher serum sodium and lower serum phosphorus than those patients with mild or moderate hypokalaemia (p<0.001). Compare to other groups, the severe hypokalaemia group had the worst outcome. Moreover, the patients (n=15) who had severe hypokalaemia, hypernatraemia (Na>160mmol/L), and hypophosphataemia (P<0.3mmol/L) all died in hospital. Multiple logistic regression analysis resulted in decrease of GCS (OR=1.27; 95% CI=1.15-1.41; p<0.001) and potassium (OR=4.35; 95% CI=2.04-9.26; p<0.001) being associated with significant increased risk of mortality.

CONCLUSIONS

The peak incidence of severe hypokalaemia occurred in the first 24-96h. TBI patients with severe hypokalaemia are more vulnerable to develop hypophosphataemia and hypernatraemia than patients with mild and moderate hypokalaemia. Severe hypokalaemia are the independent risk factors for mortality in TBI patients.

Association between Hypophosphatemia and Cardiac Arrhythmias in the Early Stage of Sepsis: Could Phosphorus Replacement Treatment Reduce the Incidence of Arrhythmias?

It is well known that new-onset arrhythmias are common in septic patients. It is thought that hypophosphatemia in the early stages of sepsis may contribute to the development of new arrhythmias. In this study, we hypothesized that intravenous (IV) phosphorus replacement may reduce the incidence of arrhythmias in critically ill patients. 34 adult septic patients with hypophosphatemia admitted to the general intensive care unit were treated with IV phosphorus replacement per ICU protocol, and the incidence of new arrhythmias were compared with 16 patients from previously published data. IV phosphorus replacement was associated with a significantly reduced incidence of arrhythmias (38% vs. 63%, p=0.04). There were no differences in observed mortality between subgroups, which may be due to the small sample size. This study demonstrated that IV phosphorus replacement might be effective in reducing the incidence of new arrhythmias in septic patients.

Phoxilium vs Hemosol-B0 for continuous renal replacement therapy in acute kidney injury

PURPOSE

This study aimed to compare the biochemical effects of Phoxilium (containing phosphate at 1.2 mmol/L; Gambro Lundia AB, Lund, Sweden) and Hemosol-B0 (Gambro Lundia AB) as dialysate and/or replacement fluid during continuous renal replacement therapy (CRRT).

METHODS

We examined serum biochemistry in critically ill patients for 42 hours of Phoxilium administration for the prevention of hypophosphatemia during CRRT and compared them with corresponding results in random historical controls who received Hemosol-B0.

RESULTS

We studied 15 patients in each arm (Phoxilium vs Hemosol-B0). Respective median ages were 57 (49-68) and 64 (57-67) years. Baseline patient illness severity scores, prescribed CRRT effluent rates, and cumulative phosphate intakes were comparable. After 36 to 42 hours of Phoxilium administration, serum phosphate levels increased from 0.95 (0.81-1.13) to 1.44 (1.23-1.78) mmol/L, in contrast to the decline from 1.71 (1.09-2.00) to 0.83 (0.55-1.59) mmol/L with Hemosol-B0 (P=.0001). Serum ionized calcium levels decreased from 1.27 (1.22-1.37) to 1.12 (1.06-1.21) mmol/L with Phoxilium, compared with an increase from 1.09 (0.90-1.19) to 1.20 (1.16-1.25) mmol/L with Hemosol-B0 (P<.0001). Serum bicarbonate, base excess levels, and effective strong ion difference decreased with Phoxilium and were lower than those with Hemosol-B0 at 36 to 42 hours (P<.05).

CONCLUSION

Phoxilium effectively prevented hypophosphatemia during CRRT but was associated with relative metabolic acidosis and hypocalcemia compared with Hemosol-B0 use.

Change of serum phosphate level and clinical outcome of hypophosphatemia in massive burn patient

BACKGROUND

Hypophosphatemia is relatively common phenomenon in patients with massive burn injury. Therefore, we check serum phosphate level routinely and try to supply phosphate in a timely manner. The purpose of this study was to investigate the change of the serum phosphate level of early postburn period and the impact of hypophosphatemia on the prognosis of patients.

METHODS

A total of 227 patients with burn injury were reviewed retrospectively. We performed analysis of serum phosphate level within 20 days from burn injury.

RESULTS

Patients' mean (SD) age was 47.0 (14.1) years, and mean (SD) percentage of total body surface area burned were 47.7 (21.9). Severe hypophosphatemia (phosphate < 1.0 mg/dL) was observed in 35 patients (15.8%), and moderate hypophosphatemia (1.0 ≤ phosphate < 2.0 mg/dL) was found in 115 patients (50.6%). Therefore, overall incidence of hypophosphatemia was 66.4%. There was no significant difference in serum phosphate level with survival, total body surface area burned, and mechanical ventilation. Age (odds ratio [OR], 3.180; 95% confidence interval [CI], 1.025-9.871; p = 0.045), total body surface area burned (OR, 20.934; 95% CI, 6.845-64.024; p = 0.000), and mechanical ventilation (OR, 5.581; 95% CI, 2.380-13.085; p = 0.002) were independently associated with mortality. However, serum phosphate level (OR, 0.828; 95% CI, 0.275-2.495; p = 0.737) does not have a statistical significance.

CONCLUSION

Although multiple studies have evaluated the efficacy and safety of phosphate repletion regimens, the effect on mortality and morbidity is not well reported. However, our results show that patients with massive burn injury have high incidence of hypophosphatemia, and hypophosphatemia can result in many complications. Therefore, routine check and supply of phosphate can be suggested in patients with massive burn injury.

LEVEL OF EVIDENCE

Prognostic study, level II.

Biochemical effects of phosphate-containing replacement fluid for continuous venovenous hemofiltration

AIMS

To examine biochemical effects of phosphate-containing replacement fluid (Phoxilium(®)) for continuous venovenous hemofiltration (CVVH).

METHODS

Retrospective comparison of respective serum biochemistry with sequential use of Accusol™ and Phoxilium, each over 48 h of CVVH.

RESULTS

We studied 15 critically ill patients. Accusol was switched to Phoxilium after 5 (4-8) days of CVVH. Respective serum biochemistry after 36-42 h of Accusol versus Phoxilium were: phosphate 1.02 (0.82-1.15) versus 1.44 (1.23-1.78) mmol/l, ionized calcium 1.28 (1.22-1.32) versus 1.12 (1.06-1.21) mmol/l, bicarbonate 24 (23-25) versus 20 (19-22) mmol/l, base excess 0 (-2 to 1) versus -4 (-6 to -3) mmol/l (p < 0.001). Cumulative phosphate intakes during respective periods were 69.6 (56.6-76.6) versus 67.2 (46.6-79.0) mmol (p = 0.45). Plasma strong ion differences were narrower with Phoxilium (p < 0.05), with similar strong ion gaps. No additional intravenous phosphate was given during Phoxilium use. Seven patients had serum phosphate >1.44 mmol/l.

CONCLUSIONS

Phoxilium versus Accusol use during CVVH effectively prevented hypophosphatemia but contributed to mild hyperphosphatemia, and is associated with relative hypocalcemia and metabolic acidosis.

Phosphate-containing dialysis solution prevents hypophosphatemia during continuous renal replacement therapy

BACKGROUND

hypophosphatemia occurs in up to 80% of the patients during continuous renal replacement therapy (CRRT). Phosphate supplementation is time-consuming and the phosphate level might be dangerously low before normophosphatemia is re-established. This study evaluated the possibility to prevent hypophosphatemia during CRRT treatment by using a new commercially available phosphate-containing dialysis fluid.

METHODS

forty-two heterogeneous intensive care unit patients, admitted between January 2007 and July 2008, undergoing hemodiafiltration, were treated with a new Gambro dialysis solution with 1.2 mM phosphate (Phoxilium) or with standard medical treatment (Hemosol B0). The patients were divided into three groups: group 1 (n=14) receiving standard medical treatment and intravenous phosphate supplementation as required, group 2 (n=14) receiving the phosphate solution as dialysate solution and Hemosol B0 as replacement solution and group 3 (n=14) receiving the phosphate-containing solution as both dialysate and replacement solutions.

RESULTS

standard medical treatment resulted in hypophosphatemia in 11 of 14 of the patients (group 1) compared with five of 14 in the patients receiving phosphate solution as the dialysate solution and Hemosol B0 as the replacement solution (group 2). Patients treated with the phosphate-containing dialysis solution (group 3) experienced stable serum phosphate levels throughout the study. Potassium, ionized calcium, magnesium, pH, pCO(2) and bicarbonate remained unchanged throughout the study.

CONCLUSION

the new phosphate-containing replacement and dialysis solution reduces the variability of serum phosphate levels during CRRT and eliminates the incidence of hypophosphatemia.

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.

Serum phosphate level in burn patients

INTRODUCTION

Despite plasma phosphate imbalance being rare, it is a relatively common finding in certain subsets of burn patients. It may occur due to the burn itself or as a result of the treatment. Severe hypophosphataemia (<1.0 mg dl(-1)) is associated with a significant morbidity and a fourfold increase in mortality. In this study, the relation between serum phosphate level and the total body surface area (TBSA) of the burn was compared.

METHODS

According to the percentage of TBSA of the burn, the patients (n=155) were divided into three groups: group A with 20-29% TBSA burns, group B with 30-39% and group C with more than 40% TBSA burns (62, 48 and 45 patients, respectively). Analysis of variance (ANOVA)-repeated measure was used to detect any statistically significant difference in the three post-burn time-points of 3rd, 6th and 9th days and the mean score of the serum phosphate level between the three groups.

RESULTS

The incidence of hypophosphataemia at 9th post-burn day in the three groups was 6.1%, 32.4% and 73.5%, respectively. There were significant differences (p<0.05) between mean serum phosphate levels of groups A and C, B and C and A and B as well. We found significant differences between the three post-burn follow-up time stages.

DISCUSSION

We have shown that hypophosphataemia, defined as mean serum phosphate levels below 3.0 mg dl(-1), was very common following burn, based on 75.6% of patients with more than 40% burn at the 3rd post-burn day. As the percentage of TBSA of burn increases, the incidence of hypophosphataemia significantly increases. We suggest that phosphate level be routinely measured after a major burn, especially in patients with a complicated course, so that appropriate replacement therapy may be started in a timely manner.

Is this the worst outcome of metabolic syndrome? Hypophosphatemia and resulting cardiac arrest during the treatment of diabetic ketoacidosis with hypertriglyceridemia

We report a case of diabetic ketoacidosis (DKA) and severe hypertriglyceridemia who developed cardiac arrest due to hypophosphatemia. He was diagnosed with diabetes and hyperlipidemia, indicating metabolic syndrome. Hypophosphatemia was caused by large insulin doses received while treating DKA, which were required because of insulin resistance owing to hypertriglyceridemia. Metabolic syndrome may have accelerated serum phosphate depletion. We suggest frequent monitoring of serum phosphate and phosphate replacement for patients with DKA and severe hypertriglyceridemia. Although such a critical condition has not been reported, it may occur during treatment of patients with poorly controlled type 2 diabetes with DKA.

A possible hypophosphatemia-induced, life-threatening encephalopathy in diabetic ketoacidosis: a case report

Hypophosphatemia, a common metabolic disorder, is usually silent and diagnosed by blood tests. However, misdiagnosis may result in delayed phosphate repletion, responsible for significant morbidity and potential mortality. We report an exceptional case of hypophosphatemia-related, life-threatening encephalopathy. A 49-year-old type-1 diabetic woman was admitted to our intensive care unit with coma and severe ketoacidosis. Initial neurologic impairment worsened despite improvement in acid-base disturbances and glucose levels. The electroencephalogram showed bilateral spikes with a background theta wave rhythm. Profound hypophosphatemia <0.20 mmol/L (<0.6 mg/dL) was diagnosed. No other cause of encephalopathy was found. Prompt phosphate repletion resulted in progressive and complete recovery. This observation allowed us to study the relations between the coma depth, the electroencephalographic findings, and the serum phosphate concentrations. Our data strongly suggest that phosphate depletion-induced encephalopathy probably originates from direct impairment of cerebral electrophysiological activity rather than from cardiac flow alteration.

Hypophosphatemia: clinical consequences and management

Current evidence regarding the clinical consequences of hypophosphatemia is not straightforward. Given the potentially different implications of hypophosphatemia among various patient groups, this commentary touches on patients with low serum phosphate after acute hospitalization, those with chronic ambulatory hypophosphatemia, and those with hypophosphatemia in the setting of advanced renal disease. Finally, this commentary examines the evidence regarding how best to replete phosphorous in the hypophosphatemic patient.

Hypophosphatemia in children hospitalized within an intensive care unit

The aims of this study were to estimate the occurrence of hypophosphatemia and to identify potential risk factors and outcome measures associated with this disturbance in children admitted to a pediatric intensive care unit. Data concerning 42 children admitted consecutively to 1 pediatric intensive care unit over a 1-year period were examined. Serum phosphorus levels were measured on the third day of admission, where levels below 3.8 mg/dL were considered indicative of hypophosphatemia. Hypophosphatemia was found in 32 children (76%), and there was a significant association between this disturbance and malnutrition (P = .04). Of the potential risk factors such as sepsis, diuretic/steroid therapy, starvation (over 3 days), and Pediatric Index of Mortality, none discriminated for hypophosphatemia. There were no associations between hypophosphatemia and mortality, length of stay in the pediatric intensive care unit, or time on mechanical lung ventilation. Hypophosphatemia was a common finding in critically ill children and was associated with malnutrition.

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.

[Prevalence of dysphosphoremia in patients admitted in intensive care unit with an impaired renal function]

OBJECTIVE

To assess the frequency of dysphosphoremia in patients admitted in intensive care unit with an impaired renal function and to determine the associated risks factors. Study design. - Epidemiological prospective study.

PATIENTS AND METHODS

The creatinine clearance and the phosphoremia were measured in 134 consecutive patients admitted in intensive care unit over a six-month period. Patients with chronic renal failure were excluded. Known risk factors for hypophosphoremia in intensive care unit were recorded.

RESULTS

Seventy-nine out of one hundred thirty-four patients (59%) had an impaired renal function (arbitrarily defined by a creatinine clearance < 60 ml/min). The proportion of patients with impaired renal function that where hypo-, normo- (0.8 to 1.2 mmol/l) or hyperphosphoremic was 16, 34 and 50% respectively. Hypophosphoremia was severe (< 0.5 mmol/l) in 5 patients, all with impaired renal function. No risk factors usually associated with hypophosphoremia could be identified.

CONCLUSION

As opposed to chronic renal failure patients who are mainly hyperphosphoremic, patients admitted in intensive care unit with an impaired renal function may present with a normo-, or hypophosphoremia. These dysphosphoremias are sometimes severe. Phosphate status should be promptly determined at admission.

Hypophosphatemia in critically ill children

The purpose of this paper is to review clinical studies on hypophosphatemia in pediatric intensive care unit patients with a view to verifying prevalence and risk factors associated with this disorder. We searched the computerized bibliographic databases Medline, Embase, Cochrane Library, and LILACS to identify eligible studies. Search terms included critically ill, pediatric intensive care, trauma, sepsis, infectious diseases, malnutrition, inflammatory response, surgery, starvation, respiratory failure, diuretic, steroid, antiacid therapy, mechanical ventilation. The search period covered those clinical trials published from January 1990 to January 2004. Studies concerning endocrinological disorders, genetic syndromes, rickets, renal diseases, anorexia nervosa, alcohol abuse, and prematurity were not included in this review. Out of 27 studies retrieved, only 8 involved pediatric patients, and most of these were case reports. One clinical trial and one retrospective study were identified. The prevalence of hypophosphatemia exceeded 50%. The commonly associated factors in most patients with hypophosphatemia were refeeding syndrome, malnutrition, sepsis, trauma, and diuretic and steroid therapy. Given the high prevalence, clinical manifestations, and multiple risk factors, the early identification of this disorder in critically ill children is crucial for adequate replacement therapy and also to avoid complications.

Serum phosphate abnormalities in the emergency department

Abnormalities in serum phosphate levels are more prevalent in certain subsets of Emergency Department patients than in the general population. Patients with diabetic ketoacidosis, chronic obstructive pulmonary disease, alcoholism, malignancy, and renal failure are at increased risk. Multiple factors, including nutritional intake, medications, renal or intestinal excretion, and cellular redistribution, are potential etiologies. The clinical manifestations of mild hypophosphatemia or hyperphosphatemia are typically minor and nonspecific (myalgias, weakness, anorexia). When the imbalance is severe, critical complications may occur (tetany, seizures, coma, rhabdomyolysis, respiratory failure, ventricular tachycardia). Mild asymptomatic hypophosphatemia can be treated with oral phosphate supplementation (15 mg/kg daily) on an outpatient basis. Patients with severe or symptomatic hypophosphatemia should be treated with IV phosphate therapy (0.08-0.16 mg/kg over 6 h) and admitted for monitoring and subsequent serum electrolyte testing. Mild asymptomatic hyperphosphatemia is commonly managed in renal failure by limiting dietary intake and reducing absorption with phosphate-binding salts. Hemodialysis may be required for severe hyperphosphatemia with symptomatic hypocalcemia.

Reversible myocardial dysfunction in critically ill, noncardiac patients: a review

OBJECTIVE

To review reversible myocardial dysfunction affecting critically ill patients without cardiac pathology.

DATA SOURCES

The bibliography for the study was compiled through a search of different databases for the period 1966-2001. References cited in the selected articles also were reviewed.

STUDY SELECTION

The selection criteria included all articles published on reversible myocardial dysfunction in critically ill patients.

CONCLUSIONS

Reversible myocardial dysfunction may develop in a situation of critical pathology, but the etiology of reversible myocardial dysfunction is not fully understood. This dysfunction may be accompanied by increases in enzyme concentrations and electrocardiographic changes. Reversible myocardial dysfunction probably is underdiagnosed, although its presence is associated with a worsening of the prognosis and with more specific therapeutic options. Further studies are necessary to define its true incidence and clinical implications.

Hypophosphatemia and hypomagnesemia induced by cooling in patients with severe head injury

OBJECT

Induced hypothermia in patients with severe head injury may prevent additional brain injury and improve outcome. However, this treatment is associated with severe side effects, including life-threatening cardiac tachyarrhythmias. The authors hypothesized that these arrhythmias might be caused by electrolyte disorders and therefore studied the effects of induced hypothermia on urine production and electrolyte levels in patients with severe head injury.

METHODS

Urine production, urine electrolyte excretion, and plasma levels of Mg, phosphate, K, Ca, and Na were measured in 41 patients with severe head injury. Twenty-one patients (Group I, study group) were treated using induced hypothermia and pentobarbital administration, and 20 patients (Group 2, controls) were treated with pentobarbital administration alone. In Group 1, Mg levels decreased from 0.98+/-0.15 to 0.58+/-0.13 mmol/L (mean +/- standard deviation; p < 0.01), phosphate levels from 1.09+/-0.19 to 0.51+/-0.18 mmol/L (p < 0.01), Ca levels from 2.13+/-0.25 to 1.94+/-0.14 mmol/L (p < 0.01), and K levels from 4.2+/-0.59 to 3.6+/-0.7 mmol/L (p < 0.01) during the first 6 hours of cooling. Electrolyte levels in the control Group 2 remained unchanged. Electrolyte depletion in Group I occurred despite the fact that moderate and, in some cases, substantial doses of electrolyte supplementation were given to many patients, and supplementation doses were often increased during the cooling period. Average urine production increased during the cooling period, from 219+/-70 to 485+/-209 ml/hour. When the targeted core temperature of 32 micro C was reached, urine production returned to levels that approximated precooling levels (241+/-102 ml/hour). Electrolyte levels rose in response to high-dose supplementation. In the control group, urine production and electrolyte excretion remained unchanged throughout the study period.

CONCLUSIONS

Induced hypothermia is associated with severe electrolyte depletion, which is at least partly due to increased urinary excretion through hypothermia-induced polyuria. This may be the mechanism through which induced hypothermia can lead to arrhythmias. When using this promising new treatment in patients with severe head injury, stroke, or postanoxic coma following cardiopulmonary resuscitation, prophylactic electrolyte supplementation should be considered and electrolyte levels should be monitored frequently.

Nutritional support in sepsis: still skeptical?

The immediate metabolic response to a septic challenge is probably adaptive, meaning that nutritional interference, mainly via the parenteral route, during this early phase of instability can do more harm than good. During the later phases, a gradual increase in enteral nutrition, at the expense of parenteral nutrition, combined with the administration of nutraceuticals such as glutamine and omega-3 fatty acids, can counteract wasting and modulate the complex inflammatory response and immunosuppression associated with sepsis. In these times of scarce resources, there is an urgent need to clearly document the efficacy of immuno/pharmaconutrients, individually and in combination, enterally or parenterally, before proposing them for routine management of septic patients in the intensive care unit.

Hypophosphataemia. Pathophysiology, effects and management on the intensive care unit

Routine detection and treatment of hypophosphataemia on the intensive care unit is commonplace. Hypophosphataemia has been associated with a multitude of clinical effects and there are many associations between correction of hypophosphataemia and improvement in symptoms. However, there is no evidence at present to support the routine correction of hypophosphataemia in the absence of clinical symptoms or signs.