Dexmedetomidine vs. Remifentanil for Sedation During AFI
Condition: Intubation, Endotracheal
Study type: Interventional
Phase: Phase 4

Summary: 
      The objective of this study is to determine the efficacy and safety of Dexmedetomidine, a
      selective alpha-2 adrenoceptor agonist, which has recently gained increased popularity for
      ICU and intraoperative sedation as a sedative during awake fiberoptic intubation, as compared
      to Remifentanil.

      The hypothesis is that Dexmedetomidine will provide at least equal if not better conditions
      (sedation and analgesia) required for awake fiberoptic intubation (Ramsay Sedation Scale 3)
      with less respiratory and cardiovascular adverse effects, as well as less recall than
      Remifentanil.
    

Detailed description: 
      Awake nasal or oral fiberoptic intubation remains the method of choice for airway management
      in the expected difficult airway. This technique requires that a patient be comfortable,
      relaxed, cooperative and able to maintain their airway with spontaneous ventilation.

      In order to achieve these conditions, the pharmacologic agent chosen for sedation should be
      short acting and highly titratable, provide the required amount of sedation and have little
      suppression of spontaneous ventilation. There have been numerous reports of the use of
      Remifentanil and Propofol used either alone or in combination to achieve this level of
      sedation.

      Remifentanil has the following advantages which makes it a useful drug for this purpose:

        1. Ultra short acting with a constant half life

        2. Anti-tussive effects which help prevent coughing with tracheal manipulation

        3. Reversible with an antagonist naloxone

        4. Attenuates cardiovascular responses to laryngoscopy

      Shortcomings of Remifentanil include undesirable side effects, such as hemodynamic
      instability and respiratory depression.

      Dexmedetomidine is a centrally acting, selective alpha-2 agonist which has gained increasing
      popularity since 1999 as a drug for sedation in ICU settings. It has also been used for
      intraoperative sedation during surgery under regional anesthesia and for awake craniotomies,
      as well as for sedation of pediatric patients in different settings. Finally, there are also
      case reports of Dexmedetomidine being used for awake fiberoptic tracheal intubation.

      Theoretically, the pharmacokinetic and pharmacodynamic properties of Dexmedetomidine make it
      an ideal drug as a single agent for sedation for awake fiberoptic intubation. Venn et al
      showed that in both healthy individuals and ICU patients, Dexmedetomidine shows a rapid onset
      and equally rapid distribution half life with quick recovery. This study also demonstrated
      stable hemodynamics during airway manipulation (extubation) with no adverse cardiovascular or
      respiratory events during the study.

      Other studies have demonstrated that Dexmedetomidine attenuates cardiovascular responses to
      laryngoscopy and intubation and reduces the need for perioperative opioids. In small doses,
      it has been demonstrated to have good sedative, amnestic and analgesic effects, as well as
      anti-sialogogue effects.

      Dexmedetomidine does, however, have some drawbacks. In higher bolus doses it can cause
      hemodynamic changes, such as excessive bradycardia and hypertension followed by hypotension.
      This drug has also been associated with decreased regional and global cerebral blood flow
      despite maintenance of MAP within the auto-regulating parameters. These deleterious effects
      are more prominent in patients with hypovolemia, systemic vasoconstriction, AV block and with
      rapid bolus infusion.
    

Intervention name(s): Remifentanil; Dexmedetomidine
Intervention type(s): Drug; Drug
Intervention MeSH terms: Dexmedetomidine; Remifentanil
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Care Provider)
Keywords: Endotracheal; Awake fiberoptic intubation; Dexmedetomidine; Remifentanil