Respiratory and Haemodynamic Effects of Conscious Sedation With Dexmedetomidine for a TAVI Procedure

Official title

Respiratory and Haemodynamic Effects Comparison of Conscious Sedation With Dexmedetomidine Versus Sedation With Remifentanil-propofol for a TAVI Procedure: a Prospective, Randomised, Single-blind Study

Overview

Transcatheter aortic valve implantation (TAVI) is now the standard procedure for elderly patients with severe aortic stenosis. This patient group is characterised by increased frailty, multiple comorbidities and limited physiological reserve, exposing them to an increased risk of intraoperative complications. The majority of TAVI procedures are now performed under conscious sedation, in order to limit the risks associated with general anaesthesia and to promote a faster recovery. However, this strategy carries a risk of intraoperative respiratory events, notably bradypnoea, oxygen desaturation and airway obstruction, particularly in elderly patients with comorbidities. The anaesthetic strategy, and in particular the type of sedation used, is likely to influence intraoperative respiratory and haemodynamic tolerance. Traditionally used agents, such as propofol combined with opioids, can induce dose-dependent respiratory depression. Conversely, dexmedetomidine, an α2-adrenergic receptor agonist, has a distinct pharmacological profile, characterised by sedation with a theoretically limited respiratory impact. However, comparative data regarding the impact of different sedation strategies on intraoperative respiratory tolerance during TAVI remain limited, justifying the conduct of this study. Dexmedetomidine is a selective α2-adrenergic receptor agonist, used in anaesthesia and intensive care for its sedative and anxiolytic properties. It induces what is known as 'cooperative' sedation, characterised by the maintenance of relative alertness, the possibility of interacting with the patient and, above all, a limited impact on spontaneous breathing. Physiologically, dexmedetomidine differs from conventional sedatives, such as propofol and opioids, in causing less respiratory depression, making it a particularly attractive option for conscious sedation. This property is essential in elderly and comorbid patients, particularly during procedures such as TAVI, where maintaining spontaneous ventilation is a major concern. Several clinical studies, particularly in procedural sedation and interventional cardiology, suggest that the use of dexmedetomidine is associated with better respiratory tolerance, with a reduction in episodes of desaturation, bradypnoea and the need for airway interventions, compared with strategies based on propofol and opioids. However, data specific to the context of TAVI under conscious sedation remain limited, particularly regarding the prospective and standardised assessment of intraoperative respiratory events. This study therefore aims to address this knowledge gap by assessing the effect of dexmedetomidine, compared with standard sedation using propofol-remifentanil, on intraoperative respiratory tolerance in patients undergoing TAVI under conscious sedation.

Interventions

• Drug Sedation with dexmedetomidine
  Loading dose (optional depending on tolerance): 0.5 µg/kg administered as a slow infusion over 10 minutes (no direct bolus to avoid bradycardia). Maintenance infusion: 0.2 to 0.7 µg/kg/h. Start at 0.4 µg/kg/h. Adjust in increments of 0.1-0.2 µg/kg/h depending on the level of sedation observed. Target: RASS -2 to 0 (patient calm, arable to verbal stimulation). Adjustment of sedation: If agitation/discomfort: * Increase Dexdor by 0.1 µg/kg/h. * If persistent: sufentanil bolus 2.5-5 µg. If si
• Drug sedation propofol and remifentanil
  Propofol and remifentanil will be administered via target-controlled infusion (TCI) pumps in accordance with standard pharmacokinetic models: Sedation will be titrated to maintain a RASS score between -2 and 0 (patient calm, arousable to verbal stimulation). Start the infusion at the lower target (propofol 0.5 µg/mL; remifentanil 1.0 ng/mL). Gradually adjust every 2-3 minutes based on RASS, signs of discomfort or pain, and haemodynamic and respiratory stability. If agitation/discomfort: Incr

Primary outcome measures

• the occurrence of an intraoperative respiratory event during a TAVI procedure performed under sedation [Time frame: during sedation for TAVI procedure]

Secondary outcome measures (6)

• Postoperative cognitive function [Time frame: the day before TAVI procedure and between 24 and 48 hours postoperatively.]
• Intraoperative blood pressure stability [Time frame: during sedation and TAVI procedure]
• Heart Rate stability during procedure [Time frame: during sedation and TAVI procedure]
• Comfort and quality of sedation [Time frame: Day 0 (at the completion of the TAVI procedure)]
• Length of hospital stay [Time frame: up to 30 days]
• Tolerance and safety [Time frame: up to 30 days]

Eligibility criteria

Inclusion criteria

• -aged 60 or over,
• undergoing transfemoral TAVI,
• treated under sedation without general anaesthesia,
• having given their written informed consent,
• with sufficient command of French to undertake cognitive tests.

Exclusion criteria

• whose first language is not English,
• who have a contraindication to dexmedetomidine,
• who require conversion to general anaesthesia during the procedure,
• or who present with major haemodynamic instability (shock, uncontrolled arrhythmia).

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Other

Study locations

Belgium · 1 center

• HUB Erasme — Brussels

Identifiers

NCT: NCT07532733 · HUB2025720

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗