Hering-Breuer reflex after bilateral lung transplant

The Hering-Breuer Reflex in Bilateral Lung Transplant Patients

This study will test whether the Hering-Breuer inflation reflex is preserved in adults recovering from bilateral lung transplant and whether changing PEEP (8 vs 12 cmH₂O) alters the reflex compared with intubated patients after non-thoracic surgery.

Quick facts

• Phase: Not applicable
• Study type: Interventional
• Enrollment: 22 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Policlinico Hospital (Academic / other)
• Locations: 1 site (Milan, Michigan)
• Trial ID: NCT07280611 on ClinicalTrials.gov

What this trial studies

This single-center, non-pharmacologic interventional study will enroll intubated adults in the ICU during early weaning after bilateral lung transplantation and a comparison group of intubated patients after major non-thoracic surgery. Investigators will elicit the Hering-Breuer inflation reflex via nasogastric tube maneuvers and quantify it using the ratio THBR/TSPONT. Reflex measurements will be made at two levels of positive end-expiratory pressure (PEEP 8 vs 12 cmH₂O) to see how end-expiratory pressure modulates the response. The transplant and control arms will be compared to determine whether the reflex is absent, attenuated, or differently modulated by PEEP in double-lung-transplant recipients.

Who should consider this trial

Good fit: Adults (age ≥18) who are intubated and in the early weaning phase in the ICU after bilateral lung transplantation, with a control group of intubated ICU patients after non-thoracic surgery.

Not a fit: Patients with single-lung or re-transplantation, urgent transplants, marked low respiratory compliance, hemodynamic instability, or high bleeding risk from nasogastric tube placement are excluded and unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, results could improve understanding of respiratory control after lung transplant and help inform ventilator weaning strategies.

How similar studies have performed: Physiologic studies have described the Hering-Breuer reflex in healthy subjects and some ICU contexts, but its status after bilateral lung transplantation and response to PEEP remains largely untested.

Eligibility criteria

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:

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.

Where this trial is running

Milan, Michigan

• Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico — Milan, Michigan, Italy (Recruiting)

Conditions Hering-Breuer Reflex; Hering-Breuer reflex; Bilateral Lung Transplant