Comparison of Laryngeal Mask Airway Supreme and Endotracheal Tube In Patients Undergoing Gynecological Laparoscopy Surgery
Condition: Anaesthesia
Study type: Interventional

Summary: 
      Endotracheal Tube (ETT) is still preferred for laparoscopic surgeries because of the fear of
      pulmonary aspiration and inadequate ventilation. Laryngeal mask Supreme (LM-S) is a single
      use device and the presence of a drain tube allows to separate the gastrointestinal and
      respiratory tracts. We planned to compare ventilation parameters and gastric distension
      scores of with LM-S vs ETT during laparoscopic gynecological surgery.
    

Detailed description: 
      This prospective, randomized and double-blind study received permission from "Dokuz Eylül
      University Medical Faculty Non-Interventional Research Ethics Committee" and after obtaining
      patients' informed consent, 100 patients with American society of anesthesiologists (ASA)
      classification group I-II, between 18-65 years, undergoing elective laparoscopic
      gynecological surgery were included.

      Patients were divided into:

      Group 1=>ETT (Endo tracheal group) (50 patients) Group 2=>LM-S (Laryngeal mask Supreme) (50
      patients) Patients and surgeons performing the operation were not aware of which airway
      device was used. The patients in the groups were determined by block randomized methods.

      Patients taken to the surgical room were given standard monitoring (non-invasive blood
      pressure measurements, electrocardiogram, and peripheral oxygen saturation measurements)
      before anesthesia induction. For preoperative sedation 0.02 mg/kg midazolam IV was
      administered.

      Patients were preoxygenated with 6 L/min oxygen for 3 minutes through a face mask.

      For anesthesia induction after 2 minutes of 0.2 µg/kg/min remifentanil and 6 mg/kg/hr
      propofol infusion, IV 1-2 mg/kg propofol , 0,5 mg/kg rocuronium bromide was administered.
      After induction patients were ventilated with 6 L/min 100% oxygen through a face mask.

      Airway devices were inserted by two researchers with more than 5 years experience.

      Anesthetic maintenance was provided by 50% O2/air mixture with 0.1-0.4 µg/kg/min remifentanil
      and 50-150 µg/kg/hr (3-9 mg/kg/hr) propofol IV infusion (24).

      Before LM-S was inserted, to lubricate the surface in contact with the palate a water-based
      gel without local anesthetic was applied to completely cover the LM-S cuff. Depending on the
      patient's body weight For <50 kg, no. 3 Between 50-70 kg, no. 4 Between 70-100 kg, no. 5 LM-S
      (The Laryngeal Mask Company Limited, Singapore) was inserted.

      After LM-S placement the cuff was inflated with air so as to have a pressure below 60 water
      of centimeter (cmH20) (cuff pressure manometer, Rusch, Germany). Two minutes after LM-S
      placement, before insufflation, 10 minutes after insufflation and trendelenburg position,
      before desufflation and before LM-S removal, cuff pressure was measured repeatedly and
      recorded. At the same time intervals in the ETT group, ETT cuff pressure was measured.

      In the ETT group for women no. 7-7.5 tube was used. The ETT cuff was inflated until the leak
      sound ceased. It was measured with a manometer to remain between 20-30 water of centimeter
      (cmH20).

      Successful placement of LM-S or ETT was confirmed by square-shaped waves observed on the
      capnogram, easy ventilation of the respiration balloon and visible chest movements. After
      successful placement of the airway device, it was covered to prevent observation of which
      device was used.

      The length of time for successful placement (duration from mouth opening to first successful
      ventilation), number of tries, and ease of placement were recorded. Ease of placement was
      evaluated by the anesthetist in charge of the airway as easy, hard or unsuccessful
      (alternative airway management).

      In a situation where airway provision was unsuccessful after 3 tries, patients without
      placement of LM-S or who could not be intubated were switched to the other group and airway
      management was provided.

      For oropharyngeal leak test after the expiratory valve was closed air was shut off, O2 was
      reduced to 3 L/min and the first pressure value when a leak sound was heard was recorded as
      the oropharyngeal leak pressure. To prevent exposure of the lungs to barotrauma, when the
      peak inspiratory pressure reached 40 cmH2O the expiratory valve was opened and the test was
      concluded. This test was repeated before peritoneal insufflation, 10 minutes later and
      immediately before desufflation and was completed by a researcher blind to the type of airway
      device inserted.

      Positive pressure respiration was begun by using a ring system, 2-4 L/min fresh gas flow and
      0.5 fraction of inspired oxygen (FiO2) volume controlled 6-8 ml/kg tidal volume and 10
      respirations/min frequency. PEEP was not administered and I:E ratio was adjusted to 1:2.
      ETCO2 was held between 35-45 mmHg, if necessary first respiration frequency was increased
      then tidal volume was increased. Permission was given for CO2 insufflation for the
      laparoscopic intervention with peritoneal interior pressure of 15 mmHg.

      Two minutes after LM-S or ETT placement, before insufflation, 10 minutes after insufflation
      and trendelenburg position, immediately before peritoneal desufflation and before airway
      device removal, ventilation parameters were evaluated.

      Respiratory measurements to be recorded: Tidal volume (TV), respiration number (RN),
      peripheral oxygen saturation (SPO2), end-tidal carbon dioxide pressure (PETCO2), peak airway
      pressure (P peak), mean airway pressure (P mean) and expiration volume per minute (VE).

      Hemodynamic measurements to be recorded: (simultaneous to the measurements above and
      additionally before induction) Systolic blood pressure (SBP), diastolic blood pressure (DBP),
      mean blood pressure (MBP) and heart rate (HR).

      Evaluation related to gastric tube:

      Immediately after airway device placement using either the LM-S drainage tube or in intubated
      patients using a 14 Ch orogastric probe within the airway, the stomach was reached and the
      gastric contents were aspirated. Ease of placement and amount of fluids aspirated were
      recorded. Ease of placement was classified by the person who inserted the orogastric probe as
      very easy, easy, difficult and very difficult.

      Immediately after the intra-abdominal laparoscopic intervention and immediately before
      peritoneal insufflation was ended, gastric distension was evaluated by a surgeon blind to the
      airway device used between 0-10 (0=empty stomach, 10=distension obstructing the surgical
      field) and the difference between the scores at the start and end of the operation was
      recorded .

      When the patient cooperated LM-S or ETT was removed and total anesthesia duration and
      peritoneal insufflation duration was recorded. Possible complications that could develop
      during airway device removal (coughing, vomiting, laryngeal stridor, laryngeal spasm or
      requirement for airway intervention) were recorded.

      After LM-S removal the presence of blood was evaluated as

        1. no blood

        2. trace amounts of blood

        3. clear amount of blood Revived patients were taken to the recovery unit and a blind
           researcher evaluated the patients' throat pain, hoarseness and presence of difficulty
           swallowing in the 1st and 24th hours. To evaluate throat pain the visual analogue scale
           was used.
    

Intervention name(s): Endotracheal Tube; Laryngeal Mask Airway-Supreme
Intervention type(s): Device; Device
Intervention description(s): ETT:Ruschelit, Teleflex Medical Snd. Bhd. Malaysia. Ref:112482; Before LM-S was inserted, to lubricate the surface in contact with the palate a water-based K-YTM gel (Johnson & Johnson Ltd. Maidenhead, UK) without local anesthetic was applied to completely cover the LM-S cuff. Depending on the patient's body weight For <50 kg, no. 3 Between 50-70 kg, no. 4 Between 70-100 kg, no. 5 LM-S (The Laryngeal Mask Company Limited, Singapore) was inserted.
Other Names:
LM-S (The Laryngeal Mask Company Limited, Singapore) serial number: 175030 lot: hmabw7
Other intervention name(s): Device: Endotracheal Tube (ETT); Group LM-S (laryngeal mask group).
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Screening
Keywords: laryngeal mask Supreme; laparoscopic gynecologic surgery; Laryngeal mask during surgery