Respiratory and Haemodynamic Effects of Conscious Sedation With Dexmedetomidine for a TAVI Procedure
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age60+
SponsorErasme University Hospital
About this trial
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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
-aged 60 or over,
undergoing transfemoral TAVI,
treated under sedation without general anaesthesia,
having given their written informed consent,
Disqualifiers
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).
Trial design
Design model
Parallel
Treatments tested in this trial
Sedation with dexmedetomidine
DrugLoading 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 significant drowsiness/bradycardia: * Reduce by 0.1 µg/kg/h. * If bradycardia \< 45 bpm: Pacemaker in place by surgical team If hypotension (SBP \< 90 mmHg): → Reduce flow rate and administer crystalloids ± vasopressor (noradrenaline)
sedation propofol and remifentanil
DrugPropofol 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: Increase Propofol by 0.2 µg/ml and Remifentanil by 0.3 ng/ml If hypoventilation (EtCO₂ \> 50 or FR \< 8) : Reduce Propofol by 0.2 µg/ml or Remifentanil by 0.3 ng/ml. If bradycardia \< 45 bpm: Pacing If hypotension (SBP \< 90 mmHg): Reduce the infusion rate and administer crystalloids ± a vasopressor (noradrenaline) Maximum remifentanil dose: 2.5 ng/mL Maximum propofol dose: 1.5 µg/mL
Treatment groups
80 Participants
are divided into 2 treatment groupsGroup A: sedation dexmedetomidineExperimental treatment 1 intervention
Group B: sedation propofol-remifentanilActive comparator 1 intervention
Trial outcomes
Primary outcomes
1
the occurrence of an intraoperative respiratory event during a TAVI procedure performed under sedation
Oxygen desaturation, defined as: * moderate desaturation with an SpO₂ ≤ 95%, * severe/significant desaturation with an SpO₂ ≤ 90%, Bradypnoea, defined as a respiratory rate \< 10 breaths per minute, Impaired ventilation as evidenced by capnography, measured using the CapnoLine® device, including: * a reduction in waveform amplitude, * respiratory irregularity, * or any abnormality consistent with hypoventilation or airway obstruction. Respiratory monitoring will be carried out continuously throughout the procedure, including monitoring of oxygen saturation, respiratory rate and capnography
Time frame
during sedation for TAVI procedureSecondary outcomes
1
Postoperative cognitive function
Changes in the MoCA (Montreal Cognitive Assessment) score between the preoperative period (performed the day before de TAVI procedure) and the postoperative period (performed between 24 and 48 hours after TAVI procedure). The MoCA is a rapid cognitive screening test, scored out of 30, used to identify mild or more severe cognitive impairment. A score of 30/30 indicates the absence of cognitive impairment. The lower the score, the more severe the cognitive impairment. Here, we will examine the difference between the pre- and post-measurements, which will be calculated statistically using the score.
Time frame
the day before TAVI procedure and between 24 and 48 hours postoperatively.2
Intraoperative blood pressure stability
Variations blood pressure during the procedure. Blood pressure will be measured in mm Hg using an arterial catheter. Need for vasopressors or corrective interventions.
Time frame
during sedation and TAVI procedure3
Heart Rate stability during procedure
Variations in haert rate (beat per minute) during the procedure. Need for corrective interventions.
Time frame
during sedation and TAVI procedure4
Comfort and quality of sedation
Assessment of patient comfort, of the anaesthetist and the operating cardiologist using Visual Analog Scale (ranging from 0 to 10). A score of 0 indicates complete dissatisfaction, whilst a score of 10 indicates maximum satisfaction
Time frame
Day 0 (at the completion of the TAVI procedure)Sponsors and contacts
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Source ClinicalTrials.gov