Effect of Laryngeal Mask Cuff Pressure in Geriatric Patients

Effect of Laryngeal Mask Cuff Pressure on Postoperative Pharyngolaryngeal Complications in Geriatric Patients

Laryngeal Mask is widely used for air-way management during anaesthesia. Pharyngolaryngeal morbidity linked to laryngeal mask use is related to correct choice of mask size, placement technique, placement of the laryngeal mask in the correct position on the larynx, cuff volume and cuff pressure. It has been stated that keeping laryngeal mask cuff pressure below 45 mmHg (60 centimeter of water(cmH2O) ) can prevent pharyngolaryngeal morbidity related to laryngeal mask (throat pain, dysphonia, dysphagia) and shown that using a manometer after Laryngeal Mask Unique placement to limit pressure within the cuff can reduce this morbidity by nearly 70%. Studies commenting on pharyngolaryngeal morbidity generally do not choose a certain age group and cover stages including very young and middle-aged groups. In the literature only one similar study on the geriatric age group was found.

The aim of this study is to compare the postoperative pharyngolaryngeal morbidity in a group with cuff pressure held to 44 mmHg (60 cmH2O with a manometer and a group with Laryngeal Mask cuff inflated without reference to pressure in the geriatric age group with indications for Laryngeal Mask Unique placement.

Study Overview

• Status: Completed
• Conditions: Anaesthesia
• Intervention / Treatment: Procedure: The placement according to the manufacturer's instructions; Procedure: Cuff inner pressure was held below 44 mmHg

Detailed Description

This study received permission from Dokuz Eylül University Medical Faculty Non-Interventional Ethics Committee and informed consent was obtained from the patients. Ninety 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 blind study.

Patients taken to the operating room were given standard monitoring (ECG, pulse oxymetry, non-invasive blood pressure) and BIS monitoring [BIS-Vista ™ (Aspect Medical Systems, USA)] before anesthesia induction.

After patients were preoxygenated with 6 L/min oxygen through a face mask for 3 minutes anesthesia induction was provided by 0.02 mg/kg midazolam, 1-2 µg/kg fentanyl and 1-2 mg/kg propofol. During respiration Airway was not used, unless there was ventilation difficulty with the face mask. Before insertion the laryngeal mask used in daily routine (Laryngeal Mask Unique® (LMU)) was lubricated with a water-based gel and the cuff was completely deflated. After induction when bispectral index (BIS) values were between 40 and 60 and sufficient chin relaxation was obtained for patients weighing less than 50 kg no. 3 LMU, for those between 50-90 kg no. 4 and for patients above 90 kg no. 5 LMU was inserted by an anesthetist with more than five years experience. The placement method was according to the manufacturer's instructions. All patients were respirated by a breathing circuit with heat and moisture filter.

After the laryngeal mask was inserted the cases were manually respirated so peak inspiratory pressure was less than 20 cmH2O and the cuff of both groups was inflated with a 20 ml injector until the leak sound ceased. To evaluate ventilation the capnogram showed square wave forms and the patients' chest movements were observed, in unsuccessful situations the procedure was repeated. During attempts depending on the patients' reactions and with the requirement of keeping BIS values between 40 and 60, an additional dose of 0.5 mg/kg propofol was administered.

After Laryngeal Mask was determined and when anesthetic depth was sufficient (BIS 40-60) the inner pressure of the LMU cuff was measured and recorded by a manometer (cuff pressure manometer, Rusch, Germany). Later groups were divided in two using a random number table. In the group with cuff pressure limitation (Group Pressure Limiting (PL), n=45) cuff inner pressure was held below 60 cmH2O (44 mmHg), while the routine group (Group Routine Care, n=45) pressure was only recorded.

Anesthesia was maintained by 50% O2:50% air mix with 1.5-2.5% sevoflurane, with sevoflurane concentration and additional fentanyl doses arranged to keep BIS between 40 and 60. All patients were respirated with positive pressure ventilation tidal volume 7-8 ml/kg, inspiring: expiring rate 1:2, respiration frequency on the capnograph end tidal carbon dioxide held between 30-35 mmHg. Oropharyngeal leak pressure measurement was recorded as the pressure value when a leak sound was heard from the mouth after the expiring valve was closed and fresh gas flow was reduced to 3 L/min. Immediately after the laryngeal mask was inserted, every 5 minutes in the first half hour and every 15 minutes after that, tidal volume, mean airway pressure, end tidal carbon dioxide levels and peripheral oxygen saturation values were recorded. If the operation lasted more than one hour a second manometric measurement was taken and stable values were maintained.

After the operation, the LMU's were removed when the patients were awake and could open their mouths on an oral command and unless necessary, aspiration was not applied.After anesthesia the patients were monitored in the recovery unit and analgesia was provided by 5-10 mg intravenous dolantin titration. A researcher blind to the groups recorded throat pain, voice loss and difficulty swallowing in the 1st and 24th hour, classifying as Likert scale ranges from 1 (none) to 4 (severe). Cases developing rare complications of recurrent laryngeal nerve, hypoglossal nerve and lingual nerve paralysis were recorded. The cases were brought to the ward when Aldrete scoring criteria were appropriate. Cases discharged early from the ward had 24th hour evaluation by telephone communication.

• Study Type: Interventional
• Enrollment (Actual): 90
• Phase: Phase 4

Contacts and Locations

Study Locations

• Turkey
  • Izmi̇r, Turkey, 35320
    • Dokuz Eylül University, School of Medicine, Department of Anesthesiology and Reanimation

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years and older (Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Above the age of 65
• ASA I-III
• Undergoing elective surgery

Exclusion Criteria:

• Patients with recent history of upper respiratory infection
• Obese patients with body-mass index above 35 kg/m2
• Symptomatic hiatus hernia
• Severe gastroesophageal reflux
• Dementia

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Screening
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Group Routine Care; The placement according to the manufacturer's instructions.	Procedure: The placement according to the manufacturer's instructions; Before insertion the laryngeal mask used in daily routine (Laryngeal Mask Unique®(LMU)) was lubricated with a water-based gel and the cuff was completely deflated. After induction when BIS values were between 40 and 60 and sufficient chin relaxation was obtained for patients weighing less than 50 kg no. 3 LMU, for those between 50-90 kg no. 4 and for patients above 90 kg no. 5 LMU was inserted by an anesthetist with more than five years experience
Experimental: Group Pressure Limiting; Cuff inner pressure was held below 44 mmHg	Procedure: Cuff inner pressure was held below 44 mmHg; cuff pressure limitation (Group Pressure Limiting (PL), n=45) cuff inner pressure was held below 60 cmH2O (44 mmHg)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Pharyngolaryngeal Morbidity Postoperative 1.Hour	The primary outcome was a composite endpoint of any pharyngolaryngeal complications such as sore throat, dysphonia and dysphagia according to Likert scale ranges from 1 (none) to 4 (severe) at postoperative 1.hour	Postoperative 1.hour

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Pharyngolaryngeal Morbidity at Postoperative 24.Hour	The primer outcome was a composite endpoint of any pharyngolaryngeal complications such as sore throat, dysphonia and dysphagia according to Likert scale ranges from 1 (none) to 4 (severe) at postoperative 24.hour	Postoperative 24.hour

Collaborators and Investigators

• Sponsor: Dokuz Eylul University
• Investigators: Principal Investigator: FERİM GÜNENÇ, M.D., Dokuz Eylül University, School of Medicine, Department of Anesthesiology and Reanimation

Study record dates

Study Major Dates

• Study Start: July 1, 2011
• Primary Completion (Actual): July 1, 2012
• Study Completion (Actual): August 1, 2012

Study Registration Dates

• First Submitted: June 28, 2014
• First Submitted That Met QC Criteria: July 11, 2014
• First Posted (Estimate): July 15, 2014

Study Record Updates

• Last Update Posted (Estimate): August 31, 2015
• Last Update Submitted That Met QC Criteria: August 5, 2015
• Last Verified: August 1, 2015

More Information

Terms related to this study

• Keywords: elderly; laryngeal masks; postoperative complications
• Other Study ID Numbers: 269-GOA