Extubation in Pediatric Patients: An Observational Study
Condition: Anesthesia, Pediatric
Study type: Observational

Summary: 
      The timing of extubation following surgery and anesthesia in young children is a complex
      decision frequently guided by the experience of the clinician. The clinician frequently must
      make a decision based on assimilating multiple cues that may or may not demonstrate that the
      patient is ready for extubation such as eye opening, conjugate gaze, spontaneous ventilation,
      and end tidal agent concentration. At this time there is no published data on the predictive
      ability of individual extubation criteria for young patients undergoing anesthesia for
      surgery so most practice is based solely on experience and anecdotal teaching. In some cases
      if the timing is misjudged and the patient is extubated too early negative airway reflexes
      such as breath holding and laryngospasm may take over creating a critical situation in which
      the patient forgoes gas exchange and rapidly desaturates with the potential for bradycardia
      and further cardiovascular collapse.

      Routine criteria used to determine fitness for extubation have been primarily described in
      the intensive care unit literature and may be less relevant in the operating room in the
      setting of routine general anesthetics. Most predictors including adequate tidal volume,
      presence of conjugate gaze, eye opening, patient movement purposeful or otherwise, low end
      tidal anesthetic agent concentration, response to physical or verbal stimulation and the
      laryngeal stimulation test have not previously been evaluated to determine their individual
      predictive value in deciding if the presently anesthetized patient now emerging is ready to
      be extubated.

      In order to perform a laryngeal stimulation test the patient must be breathing spontaneously
      and practitioner will gently move the endotracheal tube up and down stimulating the larynx.
      In patients in stage 2 of anesthesia, the clinician will typically observe a cough or series
      of coughs followed by a respiratory pause of greater than 5 seconds. In this situation the
      patient has not adequately passed through stage 2 and remains at increased risk for apnea,
      breath holding, or laryngospasm. If the patient is in stage 1 of anesthesia the clinician
      will observe a cough followed by a brief pause (less than 5 seconds) or almost immediate
      return to spontaneous ventilation.

      In conclusion, their exist no quantitative data on the predictive value of these various
      criteria for extubation and the goal of our study is determine the indivdual predictive value
      of different criteria in determing fitness for extubaion in young pediatric patients by
      recording the presence or absence of various criteria in pediatric patients at the time of
      extubation during routine anesthetic care.
    

Detailed description: 
      Objectives

      The objective of this study is to prospectively observe the frequency and predictive value of
      specific signs and criteria and correlate those with successful extubation in young children
      to determine which are present with the greatest frequency and which signs are most
      predictive of successful extubation.

      Methods and Measures

      Design

      A trained observer will prospectively observe emergence and extubation in pediatric patients
      between the ages of less than 7 years of age in which potent inhalational agents were used
      for anesthetic maintenance. They will record the presence or absence of certain accepted
      signs that a young child is ready for extubation such as eye opening, postive larygneal
      stimulation test, purposeful movement, end tidal agent concentration, and several others (see
      Appendix 1 for complete list). We will also record the use of nondepolarizing neuromuscular
      blocking drugs, use and presence of train of four monitoring, and end tidal carbon dioxide
      concentration at the time of extubation. Timing of extubation will be at the discretion of
      the attending anesthesiologist caring for the patient according to their usual practice.
      Following extubation we will observe the patient and a second checklist will be filled out
      detailing any events such as the need for continuous positive pressure with 100% oxygen,
      reintubation. The quality of extubation will be scored as either "successful," "moderately
      successful," or "failed," according to predefined criteria; see appendix 1.The investigators
      will record the oxygen saturation, respiratory rate, and presence or absence of additional
      oxygen supplementation such as "blow by," "mask oxygen" or "nasal cannula" on arrival to the
      Post anesthesia care unit, at 5, 10, and 30 minutes after arrival in the post anesthesia care
      unit. The investigators will also record the post anesthesia care unit length of stay as
      defined as the time at arrival until the time the nurse deems that the patient has recovered
      sufficiently to leave the post anesthesia care unit either for home or for their inhouse bed.

      Investigators will record age, height, weight, gender, American society of anesthesiologist
      status, type of surgery, and presence or absence of any upper respiratory infection symptoms
      in the previous 2 weeks, and any premedication, type of inhalational agent used.

      Investigators will observe patients less than 7 years old based on the operating room
      schedule.

      The study will be performed at Wake Forest Baptist Medical Center a tertiary academic medical
      center.

      Subjects selection criteria

      Pediatric patients under the age of 7 scheduled for surgery and anesthesia with an
      endotracheal tube will be observed at the time of extubation.

      • Inclusion Criteria

      Patients less than 7 years of age scheduled for surgery and anesthesia in which an
      endotracheal tube is placed for airway management and potent inhalational agents are used for
      anesthetic maintenance for which a trained study observer can be present for extubation will
      be included.

      • Exclusion Criteria

      Patients using a laryngeal mask airway or other supralaryngeal device for airway management
      during an elective procedure.

      Patients with a tracheostomy in place. Any case in which total intravenous anesthesia is
      used. Patient in which a mask alone is used for airway management.

      • Sample Size

      Using an a priori sample size calculator for multiple regression analysis based on effect
      size f2 of 0.05 in a model with 7 predictors, a probablility level of 0.05, and a statistical
      power of 80% we estimate a sample size of 293 patients. The calculator can be found at the
      following internet address: http://www.danielsoper.com/statcalc/calculator.aspx?id=1 Given
      the number of 293 patients we will observe 300 extubations.

      Interventions and Interactions:

      Interventions and interactions for the patient should be minimal since this is an
      observational study. Study personnel will monitor the pediatric operating room schedule
      during the day to look for cases where an endotracheal tube is being used for airway
      management in children less than 7 years of age. Study personnel will consult with the
      responsible anesthesia team and will prospectively record data at the time of emergence and
      extubation. They will also intermittently observe the patient in the post anesthesia care
      unit but may delegate the recording of respiratory data in the post anesthesia care unit at
      arrival, 5, 10, and 30 minutes. They will also record post anesthesia care unit length of
      stay.

      Outcome Measure(s)

      Outcome measures will be successful, moderately successful or failed extubation and the
      correlation, frequency, and predictive value of individual subjective and objective criteria
      for extubation.

      Analytical Plan

      Results will be analyzed initially using descriptive statistics and multivariate logistic
      regression analysis to determine the predictive value of different criteria for successful
      extubation and further to determine if one criteria is more predictive than another.

      Human Subjects Protection

      Subject Recruitment Methods

      Study participants will be identified by looking at the pediatric operating room schedule and
      consulting with the anesthesia team responsible for the patient to determine if they used an
      endotracheal tube for airway management and then further if they plan to extubate the patient
      at the end of the procedure. If the aforementioned is acceptable and the patient meets the
      age inclusion criteria and a member of the study is available they will observe the emergence
      and record data based on what is occurring during the emergence and extubation.

      Informed Consent

      Informed consent will not be sought as this is an observational study designed to observe
      criteria used in the routine practice of pediatric anesthesia to determine the timing of
      extubation. All clinical care will be administered at the discretion of the attending
      anesthesiologist according to their routine standard practice.
    

Intervention name(s): We are observing criteria present at extubation
Intervention type(s): Other
Intervention description(s): We will not be performing any intervention. We will only be observing what clinical data is present at the time of extubation and how predictive are different pieces of clinical data.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Pediatric Patients < 7 years of age.