Phosphate Urine Excretion in Critically Ill Patients

NCT06779331 | Active Not Recruiting

• 1 other identifier: RMC-0149-23
• Study Type: observational
• Target: 205
• Locations: 1 country
• Sites: 1

Brief Summary

Hypophosphatemia is a common disorder in critically ill patients, appearing in 15-35% of Intensive Care Unit (ICU) admissions. Its reasons are multifactorial, including sepsis, refeeding syndrome, and continuous renal replacement therapy. Hypophosphatemia is generally accepted as a predictor of poor outcomes, such as prolonged ventilation and higher mortality. However, conflicting evidence exists and several works demonstrated no effect on length of ventilation, nor mortality. We have recently demonstrated no effect of hypophosphatemia on mortality and length of ventilation. However, both parameters were affected by energy delivery to the patient, with higher energy delivery associated with lower mortality and longer length of ventilation, suggesting a complex interaction between energy delivery to the patient, hypophosphatemia appearance, and patient outcomes. This raised hypothesis that hypophosphatemia is a marker of recovery, as in fulminant hepatic failure, or recovery after hepatectomy. Phosphate is mainly an intracellular anion, with only 1% of its total body amount is extracellular. It is absorbed from the small intestine, mainly at the jejunum, both through passive para-cellular and active trans-cellular process. Phosphate is excreted in the urine, after being filtered in the glomeruli, and reabsorbed mainly in the proximal tubule (less than 10% of the reabsorption occurs in the distal nephron), by sodium-phosphate co-transporters. Phosphate regulation in the body is complex. It is regulated by vitamin D, parathyroid hormone (PTH), and fibroblast growth factor 23 (FGF-23). Therefore, phosphate regulation is affected both from intestine dysfunction and kidney injury. Although hyperphosphatemia in various kidney injury is well described, the effect of kidney function regarding phosphate excretion in critically ill patients with hypophosphatemia has been scarcely described. French and Bellomo described 7 patients who had decreased phosphate kidney reabsorption during hypophosphatemia. Charrone et. al demonstrated increased phosphate excretion after IV phosphate infusion to 47 critically ill patients with hypophosphatemia. Dickerson et. al demonstrated higher rates of hypophosphatemia in 20 thermally injured patients (compared to 20 multiple trauma patients) despite greater phosphate delivery through nutrition, along with increased (although insignificant) phosphate urinary excretion in this group. This might suggest that increased renal phosphate loss has a role in hypophosphatemia development. Better understanding these processes is important, with regard to the effect of nutritional support and hypophosphatemia effects on patients' outcomes. This study aims to describe urinary phosphate excretion in critically ill patients with regard to kidney function, phosphate serum level, and phosphate intake.

Conditions

Critically Ill Intensive Care Unit Patients

Keywords

phosphate; hypophosphatemia; hyperphosphatemia; urine collection

Outcome Measures

Primary Outcomes (1)

• 90 day mortality

  Mortality within 90 days of ICU admission.

  90 days from ICU admission

Secondary Outcomes (11)

• 28-Ventilation free days

  28 days of ICU admission

• ICU Length of stay

  90 days from ICU admissino

• hospital length of stay

  up to 90 days after ICU admission

• ICU and hospital mortality

  90 days from ICU admissino

• Differences in Glomerular Filtration Rate

  Daily during first five days of ICU admission

Study Arms (4)

early hypophosphatemia

patients who developed first hypophosphatemia (Pi\<2.5mg/dL) within 24 hours of ICU admission

hypophosphatemia

patients who developed first hypophosphatemia (Pi\<2.5mg/dL) at least 24 hours after ICU admission, within study observation period

Normophosphatemia

patients who did not develop neither hypophosphatemia (Pi\<2.5mg/dL) nor hyperphosphatemia (Pi\>4.5mg/dL) during study observation period.

Hyperphosphatemia

patients who developed hyperphosphatemia (Pi\>4.5mg/dL) during study observation period.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Critically ill patients who were admitted to the ICU

You may qualify if:

• Adult (\>18) Critically ill patients who are admitted for at least 48 hours in the ICU, who are being ventilated in the first time it's 00:00 during their admission, with a urinary foley catheter.

You may not qualify if:

• Age \< 18 years
• Pregnancy.
• Recent admission to an ICU (within 30 days)
• Chronic kidney disease treated with hemodialysis.
• Oral nutrition by the patient at admission time
• Existence of another urinary catheter (e.g nephrostomy), or ileal conduit.
• Hematuria
• RRT treatment within 48 hours of admission

Sponsors & Collaborators

• Rabin Medical Center: lead

Study Sites (1)

Rabin Medcial Center

Petah Tikva, 4941492, Israel

Location

MeSH Terms

Conditions

Hypophosphatemia; Hyperphosphatemia

Condition Hierarchy (Ancestors)

Phosphorus Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: physician

Study Record Dates

• First Submitted: January 8, 2025
• First Posted: January 16, 2025
• Study Start: September 11, 2023
• Primary Completion: April 30, 2025
• Study Completion: April 30, 2026
• Last Updated: May 28, 2025

Record last verified: 2025-05

Locations

IL (1)