Laryngeal Mask Supreme During Laparoscopic Gynecologic Surgery
Condition: Anaesthesia
Study type: Interventional

Summary: 
      Laryngeal mask (LM) use in gynecological laparoscopy, contrary to widespread opinion, does
      not increase the incidence of gastric aspiration, the failure of ventilation or the risk of
      pulmonary aspiration . LM is presented as an alternative to endo tracheal tube (ETT) in
      spontaneous or positive pressure ventilation (PPV) . LM has gained widespread popularity in
      England for gynecological laparoscopic procedures. In addition in many previous studies LM
      has been successfully shown to provide appropriate lung ventilation in laparoscopic surgical
      interventions .Miller et al. compared the use of ETT, LM-P laparoscopic gynecological
      interventions and identified advantages to LM use. The most important of these advantages was
      that, contrary to tracheal tube techniques for laparoscopic surgeries, use of supraglottic
      laryngeal devices or neuromuscular blocker agents (NBA) were not required during placement.
      Thus for laparoscopic surgeries, compared with the ETT technique, without the need for
      supraglottic laryngeal devices or muscular relaxants, it is easily placed and reduces the
      time spent in the operating room.

      Our aim; to compare the use of LM-S and ETT without neuromuscular agents for laparoscopic
      gynecological intervention with positive pressure ventilation from a surgical viewpoint and
      in terms of effect on ventilation parameters.

      Secondary aim, comparison of airway morbidity with endotracheal intubation and supraglottic.
    

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 (50 patients) Group 2=>LM-S (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 was administered. After induction patients were
      ventilated with 6 L/min 100% fraction of inspired oxygen inspired oxygen fraction oxygen
      through a face mask. Anesthesia depth was standardized in all patients using bispectral index
      monitoring. Bispectral index values were held between 40-60. Bispectral index values were
      maintained in this interval by increasing or decreasing propofol infusion by 1 mg/kg.

      Airway devices were inserted by two researchers with more than 5 years experience.

      During airway device placement according to patient reactions an extra dose of 0.5 mg/kg
      propofol was given if necessary.

      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.

      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
      centimeters of water (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 centimeters of water.

      Successful placement of LM 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 40centimeters of water 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 volume controlled 6-8 ml/kg tidal volume and 10 respirations/min frequency. Positive end
      expiratory pressure 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 arterial pressure (SAP), diastolic arterial pressure
      (DAP), mean arterial pressure (MAP) 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 F 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.

      The number of interventions with Verres needle, initial intra-abdominal pressure, duration to
      reach intra-abdominal pressure of 15 mmHg, and insufflated volume of CO2 were recorded.
      Sufficiency of pneumoperitoneum (sufficient/insufficient), and quality of airway provision
      were evaluated by the surgeon who was blind to the airway device used by giving points
      between 1-4.

      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 laryngeal supra glottic airway device 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): Laryngeal Mask Airway-Supreme; Endotracheal Tube
Intervention type(s): Device; Device
Intervention description(s): Group LM-S (Laryngeal Mask Airway-Supreme)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.; ETT
Other intervention name(s): Group LM-S; Group ETT
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Other
Keywords: laryngeal mask Supreme; laparoscopic gynecologic surgery; Laryngeal mask during surgery