Effect of Hypophosphatemia on Neuro-excursion Efficiency During Mechanical Ventilator Weaning

Hypophosphatemia in Wean

Hypophosphatemia is a common phenomenon in the ICU, and several retrospective studies have shown that hypophosphatemia is associated with prolonged mechanical ventilation in ICU patients. However, the specific mechanism and causal relationship are not clear. Previous studies have shown that phosphate infusion improves the contraction of the diaphragm induced by exogenous electrical stimulation, but the effect of hypophosphatemia and phosphate supplementation on the pathophysiology in decannulated patients on mechanical ventilation has not been confirmed. The study group hypothesized that hypophosphatemia affects neural conduction function and muscle contraction by affecting ATP synthesis. Correcting hypophosphatemia may improve respiratory muscle strength and potentially improve diaphragmatic neural conduction, ultimately improving the patient's neuromuscular conversion efficiency and facilitating discharge.

1. The attending physician evaluates the patient's ventilator condition daily and meets the disconnection criteria (spontaneous breathing, RSBI < 105 (min*ml)-1, stable hemodynamics: norepinephrine or epinephrine ≤ 0.1μg/kg/min, PEEP ≤ 8cmH2O, FiO2 ≤ 50%, no increase in ventilator support conditions in the past 24 hours, PS 10cmH2O, MAAS score 2-4, pH ≥ 7.30, discontinuation of all sedative medications). After signing an informed consent form, a diaphragm electromyography (EEG) catheter is placed. (The diaphragm EEG catheter is a gastric tube with diaphragm electromyography monitoring function, with the same placement process and risks as a regular gastric tube. There is a small probability of complications such as nasal mucosal damage.)
2. Start CPAP disconnection: Adjust the ventilator PS 10 → 0 cmH2O, and keep the other conditions unchanged. Collect ventilator parameters, diaphragm electromyography (EAdi) parameters, and diaphragm ultrasound parameters at 0, 1, 3, 5, 10, 20, and 30 minutes after the trial begins, and collect the maximum EAdi and diaphragm ultrasound during quiet state.
3. Simultaneously monitor blood inorganic phosphorus, and divide the patients into two groups: the low phosphorus group (<0.8mmol/L) and the control group (0.8-1.4 mmol/L). Low phosphorus patients receive intravenous phosphate supplementation according to the clinical phosphate supplementation protocol at our center [1-5]: patients with blood phosphorus < 0.4mmol/L receive 40mmol of glycerol phosphate sodium intravenously via infusion or injection over 4-6 hours; patients with blood phosphorus 0.4-0.8mmol/L receive 30mmol of glycerol phosphate sodium intravenously via infusion or injection; Normal phosphorus patients do not require any special treatment.
4. 24h after the first CPAP offline, patients in both groups repeated the CPAP offline process, collected related parameters, and measured blood inorganic phosphorus.

Study Overview

• Status: Recruiting
• Conditions: Weaning Failure; Hypophosphatemia; Mechanical Ventilation
• Intervention / Treatment: Drug: Sodium Glycerophosphate 216 MG/ML

• Study Type: Observational
• Enrollment (Estimated): 70

Contacts and Locations

• Study Contact: Name: Shitong Diao, MD; Phone Number: 86-13833117878; Email: diaost@foxmail.com

Study Locations

• China
  • Beijing, China, 100730
    • Recruiting
    • Peking Union Medical College Hospital
    • Contact: Jiayue Li; Email: pumchkyc@126.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Mechanical ventilation patients in the weaning stage

Description

Inclusion criteria:

age ≥18 years old; Acute respiratory failure, tracheal intubation patients; Invasive ventilator use time ≥48 hours; Clinically determined remission of primary disease, has switched to auxiliary ventilation mode and plans to go offline in the near future.

Exclusion criteria:

patients with severe neuromuscular disease; Patients with central system diseases; Patients using muscle relaxants for more than 48 hours; Patients who have been or are about to be discontinued from life support; Patients with contraindications for gastric tube insertion after esophagogastric fundus varices, digestive tract perforation, and upper digestive tract surgery; Pregnant patients; Ultrasonic window is poor.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Hypophosphatemia group; On the day of weaning, the patient's peripheral blood phosphorus was low(<0.8mmol/ L).	Drug: Sodium Glycerophosphate 216 MG/ML; Low phosphorus patients receive intravenous phosphate supplementation according to the clinical phosphate supplementation protocol at our center: patients with blood phosphorus < 0.4mmol/L receive 40mmol of glycerol phosphate sodium intravenously via infusion or injection over 4-6 hours; patients with blood phosphorus 0.4-0.8mmol/L receive 30mmol of glycerol phosphate sodium intravenously via infusion or injection; Normal phosphorus patients do not require any special treatment.
Normal phosphorus group; On the day of weaning, the patient's peripheral blood phosphorus was normal.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Neural-excursion efficiency	Diaphragm excursion/diaphragm potential	0,1,3,5,10,20,30minutes after initiation of the SBT

Collaborators and Investigators

• Sponsor: Peking Union Medical College

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2024
• Primary Completion (Actual): April 1, 2025
• Study Completion (Estimated): August 1, 2025

Study Registration Dates

• First Submitted: December 23, 2024
• First Submitted That Met QC Criteria: December 23, 2024
• First Posted (Actual): January 1, 2025

Study Record Updates

• Last Update Posted (Actual): May 31, 2025
• Last Update Submitted That Met QC Criteria: May 27, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Metabolic Diseases; Phosphorus Metabolism Disorders; Hypophosphatemia
• Other Study ID Numbers: K6646

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No