Remifentanil and Laryngeal Reflex Responses in Pediatric Patients With URI
Condition: Upper Respiratory Infections
MeSH terms: Respiratory Tract Infections
Study type: Interventional
Phase: Phase 4

Summary: 
      To describe respiratory and laryngeal responses to laryngeal stimulation during propofol
      anesthesia in children with upper airway infections. To determine whether the
      co-administration of remifentanil blunts these reflex responses. To test whether the
      co-administration of remifentanil results in a significant reduction of apnea with
      laryngospasm in these patients.

      Hypotheses:

      I: In children with a URI undergoing anesthesia with propofol, the incidence of apnea and
      laryngospasm after controlled stimulation is expected to occur 2.5 times more frequently than
      in children without URI (20 vs. 8%).

      II: The incidence of apnea and laryngospasm is diminished after administration of
      remifentanil.
    

Detailed description: 
      Patients undergoing anesthesia in the presence of an upper respiratory infection (URI) are
      very common in pediatric anesthesia practice. Although, clinical data confirm that children
      with URIs are at increased risk of perioperative complications, it has become standard
      practice not to postpone anesthesia in the presence of URI. While complications (such as
      cough, hypoxemia) can be anticipated, recognized, and treated, laryngospasm remains the most
      severe and dramatic complication. In clinical practice, patients who develop laryngospasm are
      greater than 2.5 times more likely to have an active upper respiratory infection; therefore,
      knowledge that allows for rational selections of anesthetic agents under this condition is
      highly warranted. Based on our results obtained in healthy children, the use of propofol
      appears to be most promising under these circumstances. For this reason, the laryngeal and
      respiratory reflex responses should be assessed in patients with URI anaesthetized with
      propofol.

      Commonly held believes suggest, that the administration of opioids blunts airway reflexes,
      including laryngospasm. However, in a previous study of our group in children anesthetized
      with sevoflurane the administration of fentanyl effectively blunted all airway reflexes but
      laryngospasm. These results are in contrast to those obtained in adults anesthetized with
      propofol where fentanyl also effectively blunted laryngospasm.

      In children the combined use of propofol and remifentanil has become more frequent,
      particularly because of its synergistic pharmacodynamic effect. Besides its use during
      surgical procedures, this regime is also being increasingly advocated for diagnostic
      procedures such as bronchoscopy and esophago-gastroduodenoscopy. These interventions include
      instrumentation of the airway in children that are at an increased risk of harmful effects of
      laryngeal reflex responses.

      Despite their obvious clinical significance, reflexes that involve the function of the upper
      airway are only minimally understood and information on such reflexes is scarce in
      anesthetized humans. Nonetheless, a model was developed by analyzing respiratory variables
      and endoscopic images after stimulating the laryngeal mucosa with a small amount of distilled
      water. This model was successfully adapted to the pediatric setting by our group assessing
      the impact of propofol, sevoflurane, fentanyl and lidocaine administration on laryngeal
      reflex responses in preschool children.
    

Intervention name(s): propofol, remifentanil
Intervention type(s): Drug
Intervention description(s): propofol 3micrgr/ml (TCI plasma concentration Kataria model) versus propofol 3micrgr/ml and remifentanil 0.05microgr/kg/min
Other intervention name(s): Recofol; Disoprivan; Ultiva
Intervention MeSH terms: Remifentanil; Propofol
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Anesthesia; Children; Larynx