Comparison of Weight-based Versus External Ear-size Based Technique for Selection of Laryngeal Mask Airway in Pediatric Surgical Patients.
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Aga Khan University
- Enrollment
- 136
- Locations
- 1
- Primary Endpoint
- Adequacy of Ventilation
Study Overview
Brief Summary
Laryngeal Mask Airway (LMA) is widely used in pediatric surgical patients. The manufacturer recommends the size of LMA to be used in children should be based on actual body weight but this method has several limitations. To overcome these concerns, various alternatives have been tried by different researchers, one of them is external ear size for LMA size selection. Investigators therefore would like to know whether the external ear size based method can be used for LMA size selection in pediatric surgical patients in Pakistan.
Detailed Description
OBJECTIVE:
to determine whether external ear-size is non-inferior to weight for LMA size selection in pediatric surgical patients.
INTRODUCTION:
The Laryngeal Mask Airway (LMA) is widely used in pediatric population. The manufacturer recommends the size of LMA to be used in children should be based on actual body weight. However, this method has several limitations, the range of weight for a particular size is very wide, it may not be appropriate for overweight or underweight children as it is based on actual body weight rather than ideal body weight, in emergency situations where weight of the patient is unknown the correlation between weight and size of LMA is impossible, and finally weight based recommendation may not be suitable as development of the child's oropharyngeal cavity is related to height and age rather than weight. All these factors may lead to inappropriate size selection, which may result in larger sized LMA causing trauma/injury to the airway and smaller ones causing obstruction or insufficient ventilation. To overcome these concerns various alternatives to weight based technique have been tried by different researchers in both adult and pediatric patients, one of them is external ear size. Literature revealed differences in external ear size dimensions in different ethnic population and the investigator's literature search failed to reveal any local data/study in Pakistani pediatric patients where external ear size was compared or used for size selection of the LMA. The investigators therefore would like to know whether the external ear size based method can be used for LMA size selection in pediatric surgical patients in Pakistan.
HYPOTHESIS:
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Prevention
- Masking
- Triple (Participant, Investigator, Outcomes Assessor)
Masking Description
One of the investigators will record patients' weight and external ear measurements in the study proforma. Patient's medical record (MR) number will then be send to the Research assistant/ Statistician for randomization into one of the groups (Group A or Group B). On the day of surgery, research assistant will hand over patient's group allocation in a sealed opaque envelop to one of the investigators who will not be the primary anesthetist. This investigator will determine the LMA size according to the group allocation. In case the dimensions fall between the two sizes of LMA in the ear size group, the closest one will be selected. After writing LMA size in the proforma it will be handed over to the primary anesthetist who will be blinded to patient's group allocation. Primary anesthetist (who has an experience of minimum 50 LMA insertions) will use the LMA.
Eligibility Criteria
- Ages
- 6 Months to 18 Years (Child, Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •All children aged between 6 months to 18 years of age of either sex
- •American Society of Anesthesiologist (ASA) Classification I-II
- •Elective surgical procedures in whom an LMA will be indicated
- •Procedure lasting up to 2hrs
Exclusion Criteria
- •Any external ear morphological abnormality
- •Previous external ear surgeries
- •Patient/Parent refusal
- •Children with oropharyngeal lesion
- •Any patient conditions (Gastroesophageal Re-flux Disease [GERD], hiatal hernia, incomplete NPO, bowel obstruction etc.) or procedures requiring rapid sequence induction and intubation
- •History of Upper respiratory tract infection (URTI) within the last 2 weeks
Arms & Interventions
Group A - Weight Based Method
Body Weight Based method: This is the conventional method for LMA size selection. The patient will be weighed and LMA size corresponding to their weight will be used as follows.
(LMA Size - 1 for up to 5 kg of body weight) (LMA Size - 1.5 for 5 to 10 kg of body weight) (LMA Size - 2 for 10 to 20 kg of body weight) (LMA Size - 2.5 for 20 to 30 kg of body weight) (LMA Size - 3 for 30 to 50 kg of body weight)
Group B - Ear Size Based Method
Ear Size Based method: External ear size will be measured by using a paper ruler and will be recorded in cm as follows:
Vertical length: will be measured from the most dependent portion of the lobule to the furthest portion of the auricle.
Horizontal length (width): from the tragus to the furthest part of the helix horizontally.
Dimension(cm2): Vertical length (L) × Horizontal length (width-W )
Based on these ear measurements, nearest smaller LMA size will be selected.
Intervention: Ear Size Based Method (Ambu® AuraOnce™ Laryngeal Mask Airway) (Device)
Outcomes
Primary Outcomes
Adequacy of Ventilation
Time Frame: 1 minute
Adequacy of ventilation: will be judged by an oxygen saturation of greater than or equal to 95% at a Fractional Inspired Oxygen concentration (FiO2) less than 0.5 and an end-tidal carbon dioxide (ETCO2) of 35-45 mmHg at a tidal volume of 6- 8 ml/kg Actual Body Weight (ABW) at peak airway pressure less than the oropharyngeal leak pressure (OLP), and by adjusting the respiratory rate (RR).
Proper Placement
Time Frame: 1 minute
Proper LMA placement will be assessed by chest expansion on positive pressure ventilation, absence of audible leak and a square wave capnograph waveform.
Secondary Outcomes
- Oropharyngeal Leak Pressure (OLP)(30 seconds)
- Leak fraction (LF)(1 minute)
- Incidence of mucosal injury and laryngospasm(1 minute)
Investigators
Muhammad Qamarul Hoda
Professor, Department of Anesthesiology
Aga Khan University