The Effect of Sevofluorane on Wash-out Time in COPD
Condition: Anesthesia
Study type: Observational [Patient Registry]

Summary: 
      COPD (Chronic obstructive disease ) is a condition of respiratory system failure seen
      occasionally in elderly patients of society. Sevofluorane is a safe, volatile anesthetic used
      considerably widely all over the world. Because respiratory functions and gas exchange became
      impaired in COPD patients, the respiratory system excretion/washout of inhalational
      anesthetic agents can be affected. In our study we aimed to investigate if there is a
      relation between sevofluorane's washout time and the degree of COPD.
    

Detailed description: 
      Having approval by the Duzce University non-invasive clinical ethics committee and the
      written consent, the study was conducted by researchers among 60 American Society of
      Anesthesiologists (ASA) physical status 1 or 2 patients scheduled for orthopedic, urologic
      and lower limp surgery which performed under general anesthesia .We investigated patients who
      have normal pulmonary function and who have chronic obstructive pulmonary disease .We divided
      into two groups by via questioning and evaluating pulmonary function tests of patients.

      The patients were 18-60 years old, with body mass index between 22-29. The exclusion criteria
      were:

        1. Cardiac failure

        2. Hepatic failure

        3. Renal failure

        4. Neurologic diseases

        5. Endocrine diseases Study design Neither group received premedication. After being taken
           to the operating room all patients were monitored continuously throughout the study by
           standard ASA monitors. In addition to standard ASA monitors, inspired oxygen
           concentration (FiO2 ), inspired and expired concentration of sevofluorane, MAC levels of
           the patients were monitored.

      Anesthesia was induced by propofol (2mg . kg-1), fentanyl (1,5-2 mcg. kg-1),
      rocuronium(0,6mg. kg-1) intravenously. General anesthesia was maintained by remifentanyl
      infusion(0,25-1 mcg.kg-1.min-1) and sevofluorane (1 MAC level corrected for the patients
      age). Fresh gas flow was 6 L. min-1 (50%-50% oxygen/air mixture). Patients were mechanically
      ventilated (Vt: 6-8 ml. kg-1 , frequency: 9-12 breath.min-1), adjusted to provide an
      end-tidal CO2 concentration of 35-40 mmHg and SpO2> %95 during anesthetic and surgical
      procedure.The patients non-invasive arterial tension and heart rate was maintain within
      normal limits. All data were recorded on each patient's observation charts.

      At the end of the surgery, the sevofluorane vaporizer was turned off and the time taken for
      the sevofluorane concentration to decrease from 1 MAC to 0.3 MAC (MAC awake) and 0.1 MAC were
      recorded. The ratio of the fraction of inspired of sevoflurane and of expired concentration
      (Fexp) of sevofluorane at 1 MAC and Fexp of sevofluorane at 0.1 MAC were recorded. Mechanical
      ventilations of the patients were maintained until extubation and standardized according to
      ideal body weight. All patients extubated immediately after the patients were given reaction
      to the endotracheal tube. Remifetanyl infusion was maintained until 0.1 MAC level was
      reached.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        the study was conducted by reserchers among 60 American Society of Anesthesiologists (ASA)
        physical status 1 or 2 patients scheduled for orthopedic, urologic and lower limp surgery
        which performed under general anesthesia .We investigated patientes who have normal
        pulmonary function and who have chronic obstructive pulmonary disease .We divided into two
        groups by via questioning and evaluating pulmonary function tests of patients.

        The patients were 18-60 years old, with body mass index between 22-29
      
Keywords: sevoflurane, anesthesia, washout time,COPD