A comparison of three methods for estimating appropriate tracheal tube depth in children
ABSTRACT Estimating appropriate tracheal tube (TT) depth following tracheal intubation in infants and children presents a challenge to anesthesia practitioners. We evaluated three methods commonly used by anesthesiologists to determine which one most reliably results in appropriate positioning.
After IRB approval, 60 infants and children scheduled for fluoroscopic procedures requiring general anesthesia were enrolled. Patients were randomly assigned to one of three groups: (1) deliberate mainstem intubation with subsequent withdrawal of the TT 2 cm above the carina ('mainstem' method); (2) alignment of the double black line marker near the TT tip at the vocal cords ('marker' method); or (3) placement of the TT at a depth determined by the formula: TT depth (cm) = 3 x TT size (mmID) ('formula' method). TT tip position was determined to be 'appropriate' if located between the sternoclavicular junction (SCJ) and 0.5 cm above the carina as determined by fluoroscopy. Risk ratios were calculated, and data were analysed by the chi-square test accepting statistical significance at P < 0.05.
The mainstem method was associated with the highest rate of appropriate TT placement (73%) compared with both the marker method (53%, P = 0.03, RR = 1.56) and the formula method (42%, P = 0.006, RR = 2.016). There was no difference between the marker and formula methods overall (P = 0.2, RR = 1.27). Analysis of age-stratified data demonstrated higher success with the marker method compared with the formula method for patients 3-12 months (P = 0.0056, RR = 4.0).
Deliberate mainstem intubation most reliably results in appropriate TT depth in infants and children.
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ABSTRACT: To determine, for two different age groups, the effect of duration of sevoflurane administration on the amount of propofol needed when performing tracheal intubation. Classic Dixon's Up-and-Down sequential method. University based operating rooms. 106 ASA physical status 1 and 2 patients aged one to 11 years. Patients were allocated to the 1-6 year (≥ 12 and < 72 mos) and 6-11 year (≥ 72 and < 132 mos) age groups. Midazolam 0.5 mg/kg was given orally to the 1-6 year group, and all patients were induced with 8% dialed sevoflurane and 67% nitrous oxide (N2O), with N2O discontinued and sevoflurane dialed to 5% after one minute and 1.5 minutes for the younger and older age groups, respectively. Intravenous access was obtained and propofol was promptly administered. Propofol dose was determined according to age group and whether propofol was given 2-4, 4-6, or 6-8 minutes after the start of sevoflurane induction, with Dixon's Up and Down Method used separately for each specific age/time group. Tracheal intubation conditions one minute after propofol were evaluated. Isotonic regression determined propofol ED50 estimates for excellent tracheal intubation conditions, and linear regression determined the effect of propofol dose on change in systolic blood pressure (SBP). Estimated propofol ED50 doses for 1-6 year olds, with 95% confidence intervals (CIs), were 1.48 mg/kg (0.80, 2.03), 0.00 mg/kg (0.00, 0.38), and 0.07 mg/kg (0.00, 0.68) in the 2-4, 4-6, and 6-8 minute groups, respectively, with estimated differences between the 2-4 minute group versus the 4-6 and 6-8 minute groups being 1.47 mg/kg (95% CI = 1.04, 2.06) and 1.41 mg/kg (95% CI = 0.74, 2.04), respectively. Estimated propofol ED50 doses for 6-11 year olds, with 95% CIs, were 2.35 mg/kg (1.97, 2.45) and 2.33 mg/kg (1.59, 2.45) in the 2-4 and 4-6 minute groups, respectively. Diminutions in SBP at one minute and two minutes after propofol administration were dose dependent for children 1-6 years of age, decreasing 5.3% and 8.1% for each 1 mg/kg of propofol, respectively. The amount of propofol needed to supplement sevoflurane in children 1-6 years of age can be expected to decrease after 4 minutes of sevoflurane.Journal of clinical anesthesia 01/2014; DOI:10.1016/j.jclinane.2013.08.005 · 1.21 Impact Factor
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ABSTRACT: Background Accurate positioning of the tip of the tracheal tube (tube tip) is challenging in young children. Prevalent clinical methods include placement of intubation depth marks, palpation of the tube cuff in the suprasternal notch, or deliberate mainstem intubation with subsequent withdrawal. To compare the predictability of tube tip positions, variability of the resulting positions in relation to the carina was determined applying the three techniques in each patient.Methods In 68 healthy children aged ≤4 years, intubation was performed with an age-adapted, high-volume low-pressure cuffed tube adjusting the imprinted depth mark to the level of the vocal cords. The tube tip-to-carina distance was measured endoscopically. Thereafter, placements using (I) cuff palpation in the suprasternal notch and (II) auscultation to determine change in breath sounds during withdrawal after bronchial mainstem intubation were completed in random order.ResultsTube tip position above the carina was higher when using depth marks (mean = 36.8 mm) compared with cuff palpation in the suprasternal notch (mean = 19.0 mm). Variability, expressed as sd, was lowest with the mainstem intubation technique (5.2 mm) followed by the cuff palpation (7.4 mm) and the depth mark technique (11.2 mm) (P < 0.005).Conclusion Auscultation after deliberate mainstem intubation and cuff palpation resulted in a tube tip position above the carina that was shorter and more predictable than placement of the tube using depth markings.Pediatric Anesthesia 10/2014; DOI:10.1111/pan.12552 · 1.74 Impact Factor
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ABSTRACT: Background : The aim of this study was to determine the accuracy of standard techniques for estimating oral and nasal tracheal tube length in children and to devise more accurate predictive formulae that can be used at the bedside.Methods : Data were collected from 255 children who required tracheal intubation whilst on the Pediatric Intensive Care Unit over a period of 1 year. Age, weight, the final length of the tracheal tube and the internal diameter were documented. Patients with a tracheostomy were excluded from the study.Results : Using linear regression the following formulae best predicted final tracheal tube length. For children over 1 year of age: For children below 1 year of age: Conclusions : Current Advanced Paediatric Life Support guidelines underestimate the appropriate tracheal tube lengths for orotracheal intubation in children over 1 year of age. Similarly, the novel weight-based formulae for tracheal tube lengths in children below the age of 1 year proved more accurate than standard reference charts. We therefore recommend that these new formulae are prospectively evaluated.Pediatric Anesthesia 11/2006; 16(12):1238 - 1243. DOI:10.1111/j.1460-9592.2006.01982.x · 1.74 Impact Factor
Edward Rivera Mariano