Anesthesia Intubation Complication
Conditions
Keywords
intubation of children without neuromuscular blockade
Brief summary
The purpose of this study is to determine the amount of propofol required to achieve 50% of patients obtaining a perfect (excellent) intubation score of 5 on the Steyn modification of the Helbo-Hansen Intubation Score, when placing a tracheal tube in children 1-6 years and 6-12 years (division of age groups at 6th birthday) of age, under a specific induction and ventilation sequence as specified in this study design.
Detailed description
The practice of tracheal intubation of children without neuromuscular blockade (TIWNB) is widespread in pediatric anesthesia practices. There are several different methods reported for TIWNB, most of which involve administration of an inhaled anesthetic in combination with an intravenous adjunctive medication. The technique of administering propofol IV, immediately after IV placement, after a sevoflurane induction is perhaps the most popular method for pediatric TIWNB in the United States and worldwide (personal communication, and personal practice of this technique). At the time this study was proposed, nobody had studied this technique, and therefore nobody had quantified the amount of propofol needed in this context, or considered that the amount may differ according to the time sevoflurane has been administered at the moment propofol is given. This study divides patients into two age categories, with the first age group starting at the 1 year birthday and going up to the 6th year birthday, and the second age group going from the 6th year birthday up to the 12th birthday. The study also divides participants according to time that they have received sevoflurane from the start of anesthetic induction until intravenous access is achieved and propofol immediately administered. That amount of time varies in clinical practice due to variable difficulty obtaining pediatric intravenous access, and the amount of propofol may vary according to the amount of sevoflurane administered (time administered) because depth of anesthesia will increase with increasing duration of sevoflurane administration. The purpose of this study is to determine for both age groups the amount of propofol required to achieve 50% of patients obtaining a perfect intubation score of 5 on the Steyn modification of the Helbo-Hansen Intubation Score (HH Score), when placing a tracheal tube after various time periods of administration of sevoflurane. The 3 different time windows for sevoflurane administration prior to the propofol bolus will be 2-4 minutes, 4-6 minutes, and 6-8 minutes, starting the time clock at the start of anesthetic induction and ending at the moment the propofol is given. The study therefore has 6 separate groups (2 age groups x 3 time period groups) each of which utilizes a Dixon's Up and Down Method, moving up or down on the amount of propofol administered according to the result of the previous patient in each group (HH Score of 5 labeled excellent intubation indicates allocation of predetermined (0.3 mg/kg) incrementally smaller amount of propofol and \>5 labeled as not-excellent intubation an increase of 0.3 mg/kg of propofol. Linear regression will be used for each of the 6 groups to determine the amount of propofol required to achieve 50% perfect intubation, with 95% confidence intervals also calculated.
Interventions
DRUGpropofol
Initial dose: Propofol 2 mg/kg, then dose changes separately based on the last subject in the same age group and sevo time range
Sponsors
University of Virginia
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
NONE
Intervention model description
This is a single study with 6 parallel groups as noted in the description. With Dixon's Up and Down Method for determining a 50th percentile of a dichotomous outcome, the number of patients required is not known prior to starting a study. Data from Paul and Fisher demonstrated that 6 crossovers (change in the dichotomous outcome from one patient to another, indicating change from increasing the dose of the study drug to decreasing it, or visa-versa). When choosing a meaningful starting point near the 50th percentile, the number required is typically 15-20 patients. With 6 study groups, the estimated number of patients required would be 90-120. Please Note: This is not a study where one can perform a power analysis and determine a required N.
Eligibility
Sex/Gender
ALL
Age
1 Years to 11 Years
Healthy volunteers
No
Inclusion criteria
* Informed consent / assent * Ages 1-11 years (12 - 132 months) * American Society of Anesthesiology (ASA) physical status 1 or 2, which implies that the patient has no comorbidity that limits daily function. * Scheduled for non-emergent surgery/ procedure under general anesthesia in which the anesthesia team intends to place an endotracheal tube * Expected routine intubation according to physical exam and history * Weight under 50 kg
Exclusion criteria
* Requires neuromuscular blocking agents * Emergent surgery / procedure * Expected difficult intubation * ASA physical status 3 or 4 * Weight over 50 kg * Age under 12 months or over 132 months * Allergy to study drugs to be used
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Estimated Propofol Doses Producing 50% Excellent Intubation Conditions | Amount of time it takes to intubate each patient; approximate time is 15-45 seconds | Logistic regression utilized to measure the amount of propofol to obtain 50% excellent intubation conditions for each age/time group. The quality of tracheal intubation will be graded according to the Steyn modification of the Helbo-Hansen scoring system for tracheal intubation, which includes evaluation of ease of laryngoscopy, position of the vocal cords, coughing, jaw relaxation and movement of limbs, each evaluated on a 1-4 scale, with 1 being the best possible condition and 4 the worst. The intubation conditions will be classified as either excellent or not-excellent. Excellent will be defined as a total score of 5, a score of 1 for each category, and not-excellent will be a total score of 6-20, meaning a score of \>1 in any category. While the outcome measure of each intubation is excellent or not excellent, the overall outcome being generated is the amount of propofol in mg/kg required for 50% excellent intubation score. |
Countries
United States
Participant flow
Recruitment details
Participants were recruited at an outpatient surgery center
Pre-assignment details
Four patients dropped out due to protocol violations or ended up outside the three time periods by the time IV access obtained.
Participants by arm
| Arm | Count |
|---|---|
| Age 1-6 Years, Time 2-4 Minutes of Sevoflurane Until Propofol Administration Propofol 2 mg/kg administered to first subject. Dose will be increased by 0.3 mg/kg for the next subject if intubation score is not excellent. Dose will be decreased by 0.3 mg/kg if intubation score is excellent. This dosing scheme will be continued.
propofol: Initial dose: Propofol 2 mg/kg, then dose changes separately based on the last subject in the same age group and sevo time range | 19 |
| Age 1-6 Years, Time 4-6 Minutes of Sevoflurane Until Propofol Administration Propofol 2 mg/kg administered to first subject. Dose will be increased by 0.3 mg/kg for the next subject if intubation score is not excellent. Dose will be decreased by 0.3 mg/kg if intubation score is excellent. This dosing scheme will be continued.
propofol: Initial dose: Propofol 2 mg/kg, then dose changes separately based on the last subject in the same age group and sevo time range | 26 |
| Age 1-6 Years, Time 6-8 Minutes of Sevoflurane Until Propofol Administration Propofol 2 mg/kg administered to first subject. Dose will be increased by 0.3 mg/kg for the next subject if intubation score is not excellent. Dose will be decreased by 0.3 mg/kg if intubation score is excellent. This dosing scheme will be continued.
propofol: Initial dose: Propofol 2 mg/kg, then dose changes separately based on the last subject in the same age group and sevo time range | 24 |
| Age 6-11 Years, Time 2-4 Minutes of Sevoflurane Until Propofol Administration Propofol 2 mg/kg administered to first subject. Dose will be increased by 0.3 mg/kg for the next subject if intubation score is not excellent. Dose will be decreased by 0.3 mg/kg if intubation score is excellent. This dosing scheme will be continued.
propofol: Initial dose: Propofol 2 mg/kg, then dose changes separately based on the last subject in the same age group and sevo time range | 15 |
| Age 6-11 Years, Time 4-6 Minutes of Sevoflurane Until Propofol Administration Propofol 2 mg/kg administered to first subject. Dose will be increased by 0.3 mg/kg for the next subject if intubation score is not excellent. Dose will be decreased by 0.3 mg/kg if intubation score is excellent. This dosing scheme will be continued.
propofol: Initial dose: Propofol 2 mg/kg, then dose changes separately based on the last subject in the same age group and sevo time range | 16 |
| Total | 100 |
Baseline characteristics
| Characteristic | Age 1-6 Years, Time 2-4 Minutes of Sevoflurane Until Propofol Administration | Age 1-6 Years, Time 4-6 Minutes of Sevoflurane Until Propofol Administration | Age 1-6 Years, Time 6-8 Minutes of Sevoflurane Until Propofol Administration | Age 6-11 Years, Time 2-4 Minutes of Sevoflurane Until Propofol Administration | Age 6-11 Years, Time 4-6 Minutes of Sevoflurane Until Propofol Administration | Total |
|---|---|---|---|---|---|---|
| Age, Categorical <=18 years | 19 Participants | 26 Participants | 24 Participants | 15 Participants | 16 Participants | 100 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Region of Enrollment United States | 19 Participants | 26 Participants | 24 Participants | 15 Participants | 16 Participants | 100 Participants |
| Sex: Female, Male Female | — | — | — | — | — | 0 Participants |
| Sex: Female, Male Male | — | — | — | — | — | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 106 |
| other Total, other adverse events | 0 / 106 |
| serious Total, serious adverse events | 0 / 106 |
Outcome results
Primary
Estimated Propofol Doses Producing 50% Excellent Intubation Conditions
Logistic regression utilized to measure the amount of propofol to obtain 50% excellent intubation conditions for each age/time group. The quality of tracheal intubation will be graded according to the Steyn modification of the Helbo-Hansen scoring system for tracheal intubation, which includes evaluation of ease of laryngoscopy, position of the vocal cords, coughing, jaw relaxation and movement of limbs, each evaluated on a 1-4 scale, with 1 being the best possible condition and 4 the worst. The intubation conditions will be classified as either excellent or not-excellent. Excellent will be defined as a total score of 5, a score of 1 for each category, and not-excellent will be a total score of 6-20, meaning a score of \>1 in any category. While the outcome measure of each intubation is excellent or not excellent, the overall outcome being generated is the amount of propofol in mg/kg required for 50% excellent intubation score.
Time frame: Amount of time it takes to intubate each patient; approximate time is 15-45 seconds
Population: Two patients in Age 6-11 years, 6-8 minutes, did not appear in baseline analysis population due to inadequate numbers collected in that age group and time range to be able to analyze; IV access always achieved earlier that 6 minutes due to ease of IV access.
| Arm | Measure | Value (MEAN) |
|---|---|---|
| Age 1-6 Years, Time 2-4 Minutes of Sevoflurane Until Propofol Administration | Estimated Propofol Doses Producing 50% Excellent Intubation Conditions | 1.48 mg/kg |
| Age 1-6 Years, Time 4-6 Minutes of Sevoflurane Until Propofol Administration | Estimated Propofol Doses Producing 50% Excellent Intubation Conditions | 0.00 mg/kg |
| Age 1-6 Years, Time 6-8 Minutes of Sevoflurane Until Propofol Administration | Estimated Propofol Doses Producing 50% Excellent Intubation Conditions | 0.07 mg/kg |
| Age 6-11 Years, Time 2-4 Minutes of Sevoflurane Until Propofol Administration | Estimated Propofol Doses Producing 50% Excellent Intubation Conditions | 2.35 mg/kg |
| Age 6-11 Years, Time 4-6 Minutes of Sevoflurane Until Propofol Administration | Estimated Propofol Doses Producing 50% Excellent Intubation Conditions | 2.33 mg/kg |