Critically Ill Intensive Care Unit PatientsNCT06779331
Phosphate Urine Excretion in Critically Ill Patients
An observational study of Critically Ill Intensive Care Unit Patients, run by Rabin Medical Center at 1 site in Israel.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Critically Ill Intensive Care Unit Patients
- How many people
- 205 participants
- Where
- 1 siteIsrael
- Study dates
- 11 Sep 2023to 30 Apr 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Critically ill patients who were admitted to the ICU
Who may be able to join
- 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.
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Phosphate Urine Excretion in Critically Ill Patients - a Prospective Observational Study
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.
Read the detailed description
Data collection
We will document the following data for each patient, for maximum of five days from admission:
- Demographic data, including age; sex, height, weight, admission reason to ICU.
- Acute Physiology And Chronic Health Evaluation II (APACHE II) Score (24 hours after ICU admission)
- Daily Sequential Organ Failure Assessment (SOFA) Score and SOFA components.
- Daily Ventilation status
- Daily vasopressor requirement
- Daily Renal replacement therapy (if any)
- Daily urine volume
- Daily fluid balance - including daily fluid input and output
- Daily 6 hours urine collection, with documentation of collection volume, urine creatinine, and urine electrolytes. Specimens from the first two days of admission will be sent to laboratory analysis only after the patient is admitted for more than 48 hours.
- Calculation of glomerular filtration rate (GFR) based on urine collection findings.
- Calculation of phosphate excretion amount based on urine collection findings - both maximal phosphate tubular reabsorption rate (TmP) and Fractional Excretion of phosphate (FePi).
- Daily serum phosphate and calcium levels
- Daily phosphate intake - from enteral nutrition, parenteral nutrition, and supplemental (enteral and parenteral).
- For the last 60 patients - a single measurement of PTH and vitamin D.
- Patient outcomes: ICU length of stay; Hospital length of stay; Length of ventilation; Ventilator free days at 28 days; Mortality - at ICU, during hospital admission, and at 28 \& 90 days.
- Keywords
- phosphate, hypophosphatemia, hyperphosphatemia, urine collection
- Medical subject headings
- Hypophosphatemia, Hyperphosphatemia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| 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. |
What is being measured
The primary outcome is the main question the study is designed to answer.
90 day mortality
Mortality within 90 days of ICU admission.
Measured: 90 days from ICU admission
Secondary outcomes (11)
28-Ventilation free days
Number of ventilator free days within 28 days of ICU admission
Measured: 28 days of ICU admission
ICU Length of stay
ICU admission duration
Measured: 90 days from ICU admissino
hospital length of stay
hospital admission duration
Measured: up to 90 days after ICU admission
ICU and hospital mortality
whether mortality happened during ICU/hospital admissino
Measured: 90 days from ICU admissino
Differences in Glomerular Filtration Rate
Differences in glomerular filtration rate (GFR) (ml/min)
Measured: Daily during first five days of ICU admission
Maximal tubular reabsorption of phosphate (TmP)
Differences in Maximal tubular reabsorption of phosphate (TmP) (mg/min) will be examined in each group and between groups.
Measured: Daily during first five days of ICU admission
Phosphate Balance
Differences in phosphate balance (mg) will be examined between the groups
Measured: Daily during first five days of ICU admission
Ratio of Maximal Tubular Reabsorption rate to Glomerular Filtartaion Rate (Tmp/GFR)
Differences in the ratio Tmp/GFR (mg/ml), and daily phosphate balance will be examined in each group and between groups.
Measured: Daily during first five days of ICU admission
PTH level and Vitamin D level
Differences in PTH (ng/ml) and Vitamin D (IU/ml) between groups
Measured: One measurement, during first five days of ICU admission
caloric intake
Differences in the caloric intake provided (Kcal/day) will be examined between the groups
Measured: daily measurement during first five days of ICU admission
timing of nutritional support initiation
timing of nutritional support initiation will be compared between groups.
Measured: within first five days of ICU admission
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Jan 2025
- Study start11 Sep 2023
- Primary completion30 Apr 2025
- Study completion30 Apr 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Critically Ill Intensive Care Unit PatientsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 205 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Rabin Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Liran Statlender, Rabin Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06779331
- Sponsor's protocol ID
- RMC-0149-23
- Status last verified
- May 2025
- First submitted
- 8 Jan 2025
- Last updated
- 28 May 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Statlender L, Shochat T, Moshiashvili M, Robinson E, Itzhaki MH, Bendavid I, Fishman G, Singer P, Kagan I. Evaluation of 6-hour urine creatinine clearance as the kidney component in the SOFA score: An observational cohort study. J Intensive Med. 2025 Oct 25;6(1):69-74. doi: 10.1016/j.jointm.2025.08.009. eCollection 2026 Feb.
PubMed 41736786
Study at a glance
From the registry record, last updated by the sponsor on 28 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Phosphate Urine Excretion in Critically Ill Patients - a Prospective Observational Study
- ClinicalTrials.gov ID
- NCT06779331
- Acronym / sponsor ID
- RMC-0149-23
- Keywords
- phosphate, hypophosphatemia, hyperphosphatemia, urine collection
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 205 participants (estimated)
- Lead sponsor
- Rabin Medical CenterUniversity, hospital or other
- Study start
- 11 Sep 2023 (actual)
- Primary completion
- 30 Apr 2025 (actual)
- Study completion
- 30 Apr 2026 (estimated)
- First posted
- 16 Jan 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Data collection
We will document the following data for each patient, for maximum of five days from admission:
- Demographic data, including age; sex, height, weight, admission reason to ICU.
- Acute Physiology And Chronic Health Evaluation II (APACHE II) Score (24 hours after ICU admission)
- Daily Sequential Organ Failure Assessment (SOFA) Score and SOFA components.
- Daily Ventilation status
- Daily vasopressor requirement
- Daily Renal replacement therapy (if any)
- Daily urine volume
- Daily fluid balance - including daily fluid input and output
- Daily 6 hours urine collection, with documentation of collection volume, urine creatinine, and urine electrolytes. Specimens from the first two days of admission will be sent to laboratory analysis only after the patient is admitted for more than 48 hours.
- Calculation of glomerular filtration rate (GFR) based on urine collection findings.
- Calculation of phosphate excretion amount based on urine collection findings - both maximal phosphate tubular reabsorption rate (TmP) and Fractional Excretion of phosphate (FePi).
- Daily serum phosphate and calcium levels
- Daily phosphate intake - from enteral nutrition, parenteral nutrition, and supplemental (enteral and parenteral).
- For the last 60 patients - a single measurement of PTH and vitamin D.
- Patient outcomes: ICU length of stay; Hospital length of stay; Length of ventilation; Ventilator free days at 28 days; Mortality - at ICU, during hospital admission, and at 28 \& 90 days.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| 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. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Critically ill patients who were admitted to the ICU
Key inclusion criteria (1 listed)
- 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.
Key exclusion criteria (8 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
90 day mortality
Time frame: 90 days from ICU admission
Mortality within 90 days of ICU admission.
11 secondary outcomes
28-Ventilation free days
Time frame: 28 days of ICU admission
ICU Length of stay
Time frame: 90 days from ICU admissino
hospital length of stay
Time frame: up to 90 days after ICU admission
ICU and hospital mortality
Time frame: 90 days from ICU admissino
Differences in Glomerular Filtration Rate
Time frame: Daily during first five days of ICU admission
Maximal tubular reabsorption of phosphate (TmP)
Time frame: Daily during first five days of ICU admission
Phosphate Balance
Time frame: Daily during first five days of ICU admission
Ratio of Maximal Tubular Reabsorption rate to Glomerular Filtartaion Rate (Tmp/GFR)
Time frame: Daily during first five days of ICU admission
PTH level and Vitamin D level
Time frame: One measurement, during first five days of ICU admission
caloric intake
Time frame: daily measurement during first five days of ICU admission
timing of nutritional support initiation
Time frame: within first five days of ICU admission
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 May 2025.
- Derived from this study: PubMed 41736786Statlender L, Shochat T, Moshiashvili M, Robinson E, Itzhaki MH, Bendavid I, Fishman G, Singer P, Kagan I. Evaluation of 6-hour urine creatinine clearance as the kidney component in the SOFA score: An observational cohort study. J Intensive Med. 2025 Oct 25;6(1):69-74. doi: 10.1016/j.jointm.2025.08.009. eCollection 2026 Feb.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Critically Ill Intensive Care Unit Patients, run by Rabin Medical Center at 1 site in Israel.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 28 May 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Israel. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
90 day mortality (time frame: 90 days from ICU admission). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06779331, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 May 2025.