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; 25(4). DOI:10.1111/pan.12552 · 1.74 Impact Factor
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ABSTRACT: To evaluate whether the transillumination method increased the probability of appropriate tracheal tube (TT) placement compared with the main-stem method.DesignProspective, randomized, controlled study.SettingOperating room, university hospital.PatientsEighty children < 2 years old scheduled for elective surgery undergoing general anesthesia.InterventionsTrachlight was used for the transillumination method. After intubation, patients were randomly assigned to 1 of 2 groups: (1) deliberate bronchial intubation with subsequent withdrawal of the TT to 2 cm above the carina (main-stem group) or (2) transmitted visual signal from a bright light at the TT tip on the skin at the suprasternal notch after inserting the Trachlight into the TT (transillumination group).MeasurementsThe TT tip position was assessed by chest radiograph after the procedure. Appropriate TT placement was defined when the TT tip was located between the sternoclavicular junction and 1 cm above the carina.Main ResultsAppropriate TT placement was found in 31 (80%) of 39 patients in the transillumination group and 26 (65%) of 40 in the main-stem group. The transillumination method had higher rate of appropriate TT placement than the main-stem method (P = .15; risk ratio, 1.22; 95% confidence interval, 0.93-1.61). Seven patients (18%) had proximal TT placement, and 1 (3%) had distal TT placement in the transillumination group. In the main-stem group, 7 patients (18%) had proximal TT placement, and 7 (18%) had distal TT placement.Conclusions The transillumination method was reliable for appropriate TT placement in small children < 2 years old undergoing general anesthesia, although the transillumination method was not found to be better compared with the main-stem method.Journal of Clinical Anesthesia 11/2014; 27(1). DOI:10.1016/j.jclinane.2014.09.003 · 1.21 Impact Factor
Edward Rivera Mariano