Geriatric Patients and Laryngeal Mask Unique

Anaesthesia Clinical Trial

Official title: A Comparison of Laryngeal Mask UniqueTM in Denticulate and Edentulate Geriatric Patients

Status Completed

Clinical Trial Summary

As a result of rises in living standards quality of life is progressively increasing. Combined with developments in anesthesia, surgical techniques and medication allowing more difficult and complicated interventions to be carried out, elderly patients are encountered more often in daily anesthetic practice.Reduced tone in the upper airway of geriatric patients increases the possibility of airway obstruction. In old patients with no teeth, sunken cheeks may make ventilation with a mask ineffective; perhaps even impossible.

In addition to our observations that Laryngeal mask (LM) is more difficult to place in older patients, in the literature there are very few studies on the use of LM in older patients. Sixty percent of patients over the age of 65 have no teeth. Ventilation with a mask is more difficult for patients without teeth compared to those with teeth. Laryngeal mask is an alternative airway device for patients without teeth when the face mask does not sit correctly.

The aim of this study is primarily to measure the success of placement on first try, ease and duration of insertion and oropharyngeal leak pressure of laryngeal mask Unique (LMU) in patients 65 years of age and above dentulous and edentulous elderly patients. The secondary aim is to compare the effects on the hemodynamic response occurring during placement.

Clinical Trial Description

This study received permission from Dokuz Eylül University Medical Faculty Ethics Committee and informed consent was obtained from the patients. Sixty-six patients above the age of 65 with American Society of Anesthesiologists (ASA) physiological classification group I-III, undergoing elective surgery and with indications for laryngeal mask placement participated in this prospective, randomized and double bland study.

Patients taken to the operating room were monitored for heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP), electrocardiography (ECG-Derivation II), and peripheral oxygen saturation (SpO2) before anesthesia induction. Depth of anesthesia was evaluated with a bispectral index monitor. The patients were preoxygenated with 6 L/min oxygen through a face mask for 3 minutes. For anesthesia induction 0.02 mg.kg-1 midazolam, 1-2 μg.kg-1 fentanyl and 1-2 mg.kg-1 propofol were used. Afterwards patients were given mask ventilation with 100% oxygen. Before laryngeal masks were inserted they were prepared by being lubricated with water-based gel and the cuffs were completely deflated.

After induction agents were administered when BIS values were less than 40 and sufficient chin relaxation was obtained LMU was inserted according to the standard methods determined by Brain. The LMU size was chosen based on the patient's body weight; those from 30-50 kg used no. 3, from 50-70 kg used no. 4 and those from 70-100 kg used no 5 LMU. During attempts depending on the patient reaction and to keep the BIS values below 40, an additional dose of 0.5 mg/kg propofol was administered.

The cuffs of the laryngeal mask were inflated and held at 60 centimeters of water. After the operation before the LM was removed the cuff inner pressure was measured again and recorded. The success of the first attempt at insertion of the laryngeal mask was recorded. During placement in cases with 3 unsuccessful attempts, patients were intubated to provide airway management.

Anesthesia was maintained with a 50% O2/air mix with 1.5-2.5% sevoflurane. Concentration of sevoflurane was set to keep the bispectral index value below 40.

Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), heart rate (HR) and bispectral index values (BIS) were recorded before anesthesia induction, before LM insertion and in the 1st, 2nd, 3rd and 5th minutes after LM insertion was confirmed.

The time for successful insertion was defined as the duration from mouth opening to first successful ventilation and recorded. The number of insertion attempts and ease of insertion were recorded.

Criteria indicating successful laryngeal mask placement:

1. Waves with square shape on capnogram

2. Easy ventilation with respiration balloon and observed chest movement

3. No ventilation leak with approximately 20 centimeters of water positive pressure Evaluation of ease of insertion based on likert scala (1-4 point from easy to unsuccessful).

After laryngeal mask insertion, the oropharyngeal leak test was conducted by a researcher unaware of whether the patients had teeth or not. To complete the test after the expiring valve was shut fresh gas flow was reduced to 3 L/min. When the sound of a leak was heard from the mouth the airway pressure value (OLP) was recorded. During this test airway pressure was not allowed to rise above 40 centimeters of water. From the start of the operation to the end, the patients were monitored for hypoxia (SpO2 falling below 90%) and laryngospasm. In cases where the third attempt at LM insertion was unsuccessful, if the SpO2 values fell below 90% at any time in the study or if laryngospasm developed, the patients were excluded from the study.

The duration of use of laryngeal mask (duration from insertion to removal) in both groups were recorded. After the laryngeal mask was removed it was evaluated for traces of blood. When leaving the recovery unit and 24 hours later throat pain, dysphonia and dysphagia were evaluated. Throat pain was evaluated using the VAS-10 (visual analogue scale). ;

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Investigator, Outcomes Assessor), Primary Purpose: Screening

Related Conditions & MeSH terms

• Anaesthesia

• NCT number: NCT02219282
• Study type: Interventional
• Source: Dokuz Eylul University
• Status: Completed
• Phase: Phase 4
• Start date: August 2010
• Completion date: December 2010