The Hering-Breuer Reflex in Bilateral Lung Transplant Patients
ConditionHering-Breuer Reflex
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18+
SponsorPoliclinico Hospital
About this trial
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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
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.
Disqualifiers
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);
Trial design
Design model
Parallel
Treatments tested in this trial
Nasogastric tube placement and elicitation of Hering-Breuer reflex
DeviceEnrolled 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).
Treatment groups
22 Participants
are divided into 2 treatment groupsGroup A: Bilateral Lung Transplant patientsExperimental treatment 1 intervention
Group B: Non-thoracic surgery patientsActive comparator 1 intervention
Trial outcomes
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 enrollmentSecondary 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 enrollmentSponsors and contacts
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Source ClinicalTrials.gov