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RecruitingNCT07280611HB-DLTXUpdated Dec 12, 2025

The Hering-Breuer Reflex in Bilateral Lung Transplant Patients

An interventional study of Nasogastric tube placement and elicitation of Hering-Breuer reflex in Hering-Breuer Reflex, sponsored by Policlinico Hospital. Recruiting at 1 site in Italy. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-12-12.

Sponsored by Policlinico Hospital · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
22
Allocation
Non-randomized
Ages
18 Years and older
Sex
All
01

Study summary

The goal of this clinical trial (non-pharmacologic, single-center) is to determine whether the Hering-Breuer inflation reflex is preserved-and how it is modulated by end-expiratory pressure-in adult intensive-care patients who have undergone bilateral lung transplantation.

The study will enroll men and women ≥ 18 years admitted to the ICU during the early weaning phase and will include a comparison group of intubated ICU patients after major non-thoracic surgery.

The main questions it aims to answer are:

  • Is the Hering-Breuer reflex (measured as the ratio THBR/TSPONT) absent or attenuated in double-lung-transplant recipients?
  • Does changing the level of positive end-expiratory pressure (PEEP 8 vs 12 cmH₂O) influence the reflex?

Comparison group: Researchers will compare the transplant arm (post-bilateral lung transplantation) with the control arm (post-operative, non-thoracic surgery patients) to see whether loss or blunting of the reflex-and its response to PEEP-differs between the two cohorts.

Participants will:

  • Have a nasogastric catheter with embedded electrodes positioned to record the electrical activity of the diaphragm (EAdi).
  • Be ventilated in pressure-support mode at two preset PEEP levels (8 cmH₂O and 12 cmH₂O) during the weaning phase.
  • Receive one standardized high-volume insufflation at \~30 cmH₂O in each PEEP condition to elicit the reflex, while EAdi, airway pressures, inspiratory/expiratory times, and tidal volumes are recorded for 10 minutes per level.
02

Conditions studied

  • Hering-Breuer Reflex

Keywords

  • Hering-Breuer reflex
  • Bilateral Lung Transplant
03

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Age >18 years;
  • Both sexes;
  • For group 1: patients admitted to the Intensive Care Unit after undergoing bilateral lung transplantation, during respiratory weaning;
  • For group 2: patients admitted to the Intensive Care Unit for support or monitoring after non-thoracic surgery, who will arrive intubated.

Exclusion criteria

Exclusion Criteria:

For group 1, patients meeting at least one of the following criteria will be excluded:

  • Re-transplantation or single-lung transplantation;
  • Urgent lung transplantation;
  • Post-transplant respiratory system compliance \< 30 mL/cmH₂O;
  • Hemodynamic instability (defined as the presence of one or more of the following: plasma lactate > 4 mmol/L, need for vasoactive support with norepinephrine and/or epinephrine at a dose > 0.05 mcg/kg/min, systolic arterial pressure \< 80 mmHg);
  • Increased risk of bleeding related to the placement of a nasogastric tube due to coagulopathy or severe thrombocytopenia (INR > 2 and platelets \< 70,000);
  • Pregnancy

For group 2, patients presenting with one or more of the following criteria will be excluded:

  • Postoperative respiratory system compliance \< 30 mL/cmH₂O;
  • Hemodynamic instability (defined as the presence of one or more of the following: plasma lactate > 4 mmol/L, need for vasoactive support with norepinephrine and/or epinephrine at a dose > 0.05 mcg/kg/min, systolic arterial pressure \< 80 mmHg);
  • Contraindications to nasogastric tube placement (gastroesophageal surgery within the last 3 months, gastroesophageal bleeding in the previous 30 days, esophageal varices, facial trauma);
  • Increased risk of bleeding related to the placement of a nasogastric tube due to coagulopathy or severe thrombocytopenia (INR > 2 and platelets \< 70,000);
  • History of lung transplantation or major thoracic surgery;
  • Pregnancy.
04

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
22 participants (estimated)

Study arms

  • Experimental
    Bilateral Lung Transplant patients

    This group include patients admitted to the Intensive Care Unit for post-operative care following bilateral lung transplantation during the weaning phase from mechanical ventilation. The following patients will be excluded: minors, those undergoing retransplantation, single-lung transplantation or urgent lung transplantation; patients with respiratory system compliance \< 30 mL/cmH2O; haemodynamically unstable patients and those at increased risk of bleeding due to nasogastric tube placement.

    Device: Nasogastric tube placement and elicitation of Hering-Breuer reflex

  • Active comparator
    Non-thoracic surgery patients

    This group include patients admitted to the Intensive Care Unit for post-operative care or monitoring after non-thoracic surgery. The following patients will be excluded: minors, those who had undergone previous lung transplant or thoracic surgery; patients with respiratory system compliance \< 30 mL/cmH2O; haemodynamically unstable patients; those at increased risk of bleeding due to nasogastric tube placement and patients with contraindications to nasogastric tube placement.

    Device: Nasogastric tube placement and elicitation of Hering-Breuer reflex

Interventions

  • DeviceNasogastric tube placement and elicitation of Hering-Breuer reflex

    Enrolled patients will have a nasogastric tube placed, through which diaphragmatic electrical activity will be measured. Patients will be ventilated in pressure support mode with an expansion breath delivered at a maximum pressure of approximately 30 cmH2O in order to elicit the Hering-Breuer Reflex. Diaphragmatic electrical activity, timing, volumes and pressures will then be analyzed before and after the expansion breath over a 10 minute period, testing two levels of PEEP (8 and 12 cmH2O).

05

What researchers measure

Primary outcomes

  1. THBR/TSPONT ratio

    Comparison of the ratio between the diaphragm electrical activation time after a high-volume breath aimed at eliciting the HBR (THBR) and a spontaneous breath (TSPONT), i.e., the THBR/TSPONT ratio, between patients who underwent bilateral lung transplantation and those who underwent non-thoracic surgery.

    Time frame: At the enrollment

Secondary outcomes

  1. The variation of the THBR/TSPONT ratio as a function of PEEP

    Variation of the THBR/TSPONT ratio calculated at two different PEEP levels (8 and 12 cmH₂O) in patients who underwent bilateral lung transplantation and in those who underwent non-thoracic surgery.

    Time frame: At the enrollment

06

Study locations

1 of 1 sites recruiting
  • Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico
    Milan, Michigan 20122, Italy
    Recruiting
07

References and documents

Individual participant data

Plan to share: Yes

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT07280611
Lead sponsor
Policlinico Hospital
Responsible party
Giacomo Grasselli (Head of department of Anestesia and Intensive care unit, Policlinico Hospital) — Principal investigator
First posted
Dec 12, 2025
Start date
Oct 7, 2025
Primary completion
Jan 2026 (estimated)
Completion
Jun 2026 (estimated)
Last update
Dec 12, 2025

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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