To Compare Effect of Sevoflurane Versus Desflurane on the Return of Swallowing Reflexes in the Elderly
Condition: Pulmonary Aspiration
Study type: Interventional
Phase: Phase 4

Summary: 
      Anaesthesia and surgery has become more common in the elderly as the population survives
      longer. Anaesthesia in the elderly confers a higher risk which is related to the aging
      process and the diseases that accompany seniority. As such, there is a need to provide
      optimal anaesthetic management in order to minimize complications and risks perioperatively.
      One of the changes associated with ageing is the progressive decrease in protective laryngeal
      reflexes. Any depression of upper airway reflexes increases the chance of pulmonary
      aspiration and compromises the maintenance of the airway.

      Desflurane is an inhalational agent strongly favored due to its lower solubility in blood,
      lean tissue and fat as compared to sevoflurane. This enables the agent to be quickly
      eliminated at the end of surgery, with minimal metabolic breakdown, thus facilitating more
      rapid emergence as compared to sevoflurane anesthesia in elderly undergoing general
      anaesthesia. McKay et al conducted a study in 2005 in US, which showed that the choice of
      inhalational agent itself can influence the return of protective airway reflexes. In the
      study, the inhalational agent sevoflurane was found to cause significant impairment of
      swallowing, in comparison with desflurane(1). However, the aforementioned study focussed on
      the general population. As such, the purpose of this study is to determine whether the choice
      of inhalational anesthetic (sevoflurane versus desflurane) has similar influence on the
      return of protective airway reflexes in the geriatric population in Malaysia, and whether the
      significance is greater in the elderly population.
    

Detailed description: 
      This is a prospective, double-blind, randomized controlled trial by single operator. American
      Society of Anaesthesiologists' classification of physical status I-II male and female
      patients aged 60-85 year scheduled to have general anesthesia for surgical procedures were
      recruited. Patients recruited will be given 20mls of water to swallow in the upright position
      prior to surgery after obtaining informed consent. All patients enrolled are judged to have
      adequate swallowing if no coughing or drooling occurred after the water passed into the
      mouth, and no water remained in the oropharynx upon subsequent visual inspection.

      The anaesthetist in charge of the patients enrolled in the study will be given a sealed
      envelope containing the name of the randomised gas to be used for the patient. At the end of
      surgery, an observer who is blinded to the anaesthethic allocation will record the relevant
      data. The blinded observer determined the time to first appropriate response to command
      (asking the patient to 'open his/her eyes' or squeezing the observer's hand, state his/her
      name or state date of birth) every 30s after discontinuation of anesthetic administration and
      removal of LMA. Exactly 5 minutes after appropriate verbal response, patient was asked to
      swallow 20mls of water in a 30 degree upright position. Successful swallowing is defined as
      ingestion of the 20mls of water without coughing or drooling. If swallowing was successful,
      the study was concluded. If it was unsuccessful, the patient was asked to swallow at 5, 10,
      15, 20, 25 and 30 minutes, with termination of participation after successful swallowing. A
      stopwatch will be used to time the duration to recovery.

      A study sample size of 60 is selected, with a power of 0.80 taken as the standard of
      adequacy. A p-value of < 0.05 is taken as the criteria for the test result to be
      statistically significant and data will be analyzed.
    

Intervention name(s): Sevoflurane; Desflurane
Intervention type(s): Drug; Drug
Other intervention name(s): Sevorane
Intervention MeSH terms: Sevoflurane; Desflurane
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: sevoflurane; desflurane; protective airway reflexes; elderly