Oxygen Reserve Index in One-Lung Ventilation During Elective Thoracic Operations
Condition: One-Lung Ventilation; Hypoxemia During Surgery; Oxygen Reserve Index; Perfusion Index; Pleth Variability Index
MeSH terms: Hypoxia
Study type: Observational [Patient Registry]

Summary: 
      The investigators' goal is to perform an observational cohort study investigating the use of
      oxygen reserve index (ORi) in patients undergoing elective thoracic surgery and one-lung
      ventilation (OLV). For this purpose, ORi values are recorded and compared to the other
      collected hemodynamical and oximeter parameters. The primary hemodynamic parameters include
      heart rate (HR) and blood pressure (BP), while; oximeter device-related parameters include
      peripheral oxygen saturation, perfusion index (PI), and pleth variability index (PVI).

      The investigators' secondary goal is to investigate relationships between these hemodynamical
      and oximeter parameters using statistical analysis methods.
    

Detailed description: 
      The main objective of this study is to investigate the possible benefits of using the oxygen
      reserve index (ORi) parameter during one-lung ventilation (OLV) and elective thoracic
      operations. For this purpose, ORi values are compared to primary hemodynamical parameters of
      blood pressure (BP) and heart rate (HR) and Meanwhile, a device from Masimo Inc, USA,
      provides oximeter-related parameters, including peripheral oxygen saturation, perfusion index
      (PI), and pleth variability index (PVI). The secondary objective is to investigate possible
      statistically significant correlations between these hemodynamical and oximeter parameters
      using appropriate statistical methods.

      The study participants are patients undergoing video-assisted thoracotomy surgical procedures
      (VATS) or open thoracotomy for suspicion and possible lung tumor removal. The surgical
      operation of either lobectomy, pneumonectomy, lung biopsy, or wedge resection is considered
      during this procedure. The inclusion and exclusion criteria are summarized in another section
      of the clinicaltrials.gov registration document. All patients in the study receive a similar
      anesthetic management protocol. Premedication is not required in the study. After admitting a
      patient to the operating theatre, pulse oximetry SpO2, electrocardiogram, and noninvasive
      blood pressure monitoring are established. Heart rate (HR), mean arterial pressure (MAP),
      systolic blood pressure (SBP), and diastolic blood pressure (DBP) are measured at certain
      time points. Anesthesia requires induction of anesthesia with intravenous doses of propofol
      (Pofol, Fresenius Pharmaceutical, Turkey), 2 to 3 mg/kg, rocuronium (Esmeron, Organon
      Pharmaceuticals, U.S.A.) at a dose of 0.6 mg/kg, and fentanyl (Janssen fentanyl, Janssen
      Pharmaceutical, Belgium) at a dose of 2 to 3 mcg/kg. Tracheal intubation requires the use of
      a left Robertshaw double-lumen tube. During anesthesia, one-lung ventilation (OLV) is
      provided to all patients in addition to mechanical ventilation. The anesthesia maintenance
      includes inhalational anesthetic of sevoflurane (Sevorane, Abbott Pharmaceutical, USA) at an
      end-tidal concentration of 1 to 2% to provide a sufficient minimum alveolar concentration to
      establish anesthesia and intravenous fentanyl boluses at a dose of 0.2 mcg/kg every hourly to
      provide analgesia and to keep mean arterial blood pressure between 60 and 80 mmHg. In
      addition to standard follow-up parameters, oxygen reserve index (ORi), perfusion index (PI),
      pleth variability index (PVI) is monitored for each patient at certain time points. Hypoxemia
      during OLV was defined as peripheral oxygen saturation (SpO2) value of less than 95% when the
      inspired oxygen fraction (FiO2)value is equal to or greater than 60% on a pulse oximetry
      device. Hemodynamic and oximeter data were continuously monitored. The parameters that are in
      need of investigation include; MAP, SBP, DBP, HR, SpO2, PaO2, ORi, PI, and PVI values. These
      data are monitored at thirteen different time points during the period of anesthesia
      induction and maintenance of the surgery. The device used in this study is called the
      Radical-7 Pulse CO-Oximeter device for the measurement of ORi, PI, and PVI. A correlation
      between these values was investigated on the continuous graphs. The duration of surgery,
      anesthesia, OLV, and total 100% oxygen application time are recorded. Blood gas analysis was
      provided at DL5 at a 5-minute time point and blood gas analysis was performed for prolonged
      surgeries and for surgeries with high bleeding performance that required other analysis.
      Routinely, patients are ventilated with 50% FiO2 (50% oxygen + 50% air mixture, 1
      liter/minute fresh gas flow) after induction. The value of FiO2 rises depending on pulse
      oximeter values between the values of 60% and 100% in order to keep SpO2 values greater than
      94. The incidence of thromboembolic complications, arrhythmia, pneumonia, the duration of
      hospital and intensive care unit stay is recorded.
    

Intervention name(s): Masimo Radical-7 Pulse CO-Oximeter
Intervention type(s): Device
Intervention description(s): The Masimo Radical-7 Pulse CO-Oximeter is a device for the measurement of pulse oximetry, oxygen reserve index (ORi), perfusion index (PI), and pleth variability index (PVI). The device is the product of a company called Masimo Inc, Irvine, CA, USA
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        From a total of fifty-nine patients, 50 patients underwent either video-assisted thoracic
        surgery or open thoracotomy after a diagnosis of a suspicious lung tumor.
      
Keywords: ventilation; hypoxemia; one-lung ventilation; oxygen; perfusion