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Tube Size (tube + size)

Distribution by Scientific Domains
Medical Sciences71%

Selected Abstracts

Frontal Polymerization Synthesis of Starch-Grafted Hydrogels: Effect of Temperature and Tube Size on Propagating Front and Properties of Hydrogels

CHEMISTRY - A EUROPEAN JOURNAL, Issue 12 2006
Qing-Zhi Yan Prof. Dr.
Abstract The frontal polymerization process was used to produce superabsorbent hydrogels based on acrylic acid monomers grafted onto starch. Using a simple test tube which was nonadiabatic and permitted contact with air, the effects of initial temperature and tube size on the propagating front of grafting copolymerization and the properties of hydrogels were explored. The unrestricted access of the reaction mixture to oxygen delayed the formation of self-propagating polymerization front. The ignition time was markedly lengthened with the increasing of tube size attributed to the formation of large amounts of peroxy radicals. The front velocity dependence on initial temperature could be fit to an Arrhenius function with the average apparent activation energy of 24 kJ,mol,1, and on tube size to a function of higher order. The increase of the initial temperature increased the front temperature, which lead to more soluble oligomers and higher degree of crosslinking. The interplay of two opposite effects of oligomer and crosslinking determined the sol and gel content. An increase in tube size had two effects on the propagating front. One was to reduce heat loss. The other effect was to increase the number of escaping gas bubbles. The combined action of the two effects resulted in a maximum value of front temperature, an increase in sol content and a reduction in gel content with tube size. The highest swelling capacity of hydrogels was obtained when the initial temperature or tube size favored a formation of porous microstructure of hydrogels. [source]

Can the Broselow Tape Be Used to Estimate Weight and Endotracheal Tube Size in Korean Children?

ACADEMIC EMERGENCY MEDICINE, Issue 5 2007
Hye Young Jang MD
BackgroundThe Broselow pediatric emergency tape (BT) was developed to provide a length-based estimate of body weight and equipment size during resuscitation. ObjectivesTo conduct a validation study on the use of the BT in Korean children. MethodsAnesthesia records from children were retrospectively reviewed. The measured weights of the subjects were compared with the BT weight estimates by using Bland-Altman analysis. The accuracy of the BT and age-based formula in predicting the endotracheal tube (ETT) size were also compared. The authors drew a receiver operating characteristics (ROC) curve to evaluate the cutoff height that would be acceptable for the application of BT without error in Korean children. ResultsA total of 665 children (mean [± SD] age, 5.1 [± 3.3] years, 61.8% male) were enrolled. The average measured weight of the Korean children was 1.54 kg heavier than the BT estimates (95% CI = 1.24 to 1.85 kg). The BT estimates showed better agreement with the actually used ETT sizes than did the age-based formula estimates (86.9% vs. 34.9%, p < 0.001). The cutoff height of the ROC curve was 127.15 cm. When the BT was used in children who were shorter than the cutoff height, 98.8% of the enrolled children's estimated weights were within the limits of agreement. ConclusionsThe BT can be used in Korean children as a helpful adjunct during resuscitation to estimate the weight and ETT size. [source]

Endotracheal tube size and sore throat following surgery: a randomized-controlled study

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2010
M. JAENSSON
Background: Sore throat following endotracheal intubation is a common problem following surgery and one of the factors that affects the quality of recovery. This study was carried out with the primary aim of assessing whether the size of the endotracheal tube (ETT) affects the risk of sore throat in women following anaesthesia. Methods: One hundred healthy adult women undergoing elective surgery were randomly allocated to oral intubation with either ETT size 6.0 or 7.0. Anaesthesia was based on either inhalation or total intravenous anaesthesia according to standardized routines. Pre- and post-operatively, sore throat and discomfort were assessed on a four-graded scale and for hoarseness on a binary scale (yes or no). Post-operatively, the assessments were performed after 1,2 and 24 h, and if there was discomfort at 24 h, a follow-up call was made at 72 and 96 h. Results: After 1,2 h post-operatively, there were a higher proportion of patients with sore throat in ETT 7.0 vs. ETT 6.0 (51.1% vs. 27.1%), P=0.006. This difference between the groups was also evident, P=0.002, when comparing changes between the pre- and the post-operative values. The severity of discomfort from sore throat was also higher in ETT 7.0 (38.8%) compared with ETT 6.0 (18.8%), P=0.02. No differences were found in the incidence of hoarseness between the groups. The remaining symptoms lasted up to 96 h post-operatively in 11%, irrespective of the tube size. Conclusion: Use of a smaller-sized ETT can alleviate sore throat and discomfort in women at the post-anaesthesia care unit. [source]

CASE REPORT: The unrecognised difficult extubation: a call for vigilance

ANAESTHESIA, Issue 9 2010
J. Antoine
Summary Tracheal extubation remains a critical and often overlooked period of difficult airway management. A 66-year-old man, scheduled for C5,C7 anterior fusion, with an easy view of the vocal cords, presented with a sublaryngeal obstruction that required a reduced tracheal tube size. Despite correct tube placement, intra-operative ventilation remained difficult. At the end of surgery a pulsatile tracheal compression was fibreopticially observed above the carina. After discussion with the attending otolaryngologist, neuromuscular blockade was antagonised and the patient was able to maintain normal minute volumes while spontaneously ventilating. With the otolaryngologist present, and with the patient conscious, the trachea was successfully extubated over an airway exchange catheter. A subsequent CT scan revealed an impingement of the trachea by the innominate artery and a mildly ectatic ascending and descending aorta that, in conjunction with tracheomalacia and neuromuscular blockade, could explain the observed signs and symptoms. [source]

Frontal Polymerization Synthesis of Starch-Grafted Hydrogels: Effect of Temperature and Tube Size on Propagating Front and Properties of Hydrogels

CHEMISTRY - A EUROPEAN JOURNAL, Issue 12 2006
Qing-Zhi Yan Prof. Dr.
Abstract The frontal polymerization process was used to produce superabsorbent hydrogels based on acrylic acid monomers grafted onto starch. Using a simple test tube which was nonadiabatic and permitted contact with air, the effects of initial temperature and tube size on the propagating front of grafting copolymerization and the properties of hydrogels were explored. The unrestricted access of the reaction mixture to oxygen delayed the formation of self-propagating polymerization front. The ignition time was markedly lengthened with the increasing of tube size attributed to the formation of large amounts of peroxy radicals. The front velocity dependence on initial temperature could be fit to an Arrhenius function with the average apparent activation energy of 24 kJ,mol,1, and on tube size to a function of higher order. The increase of the initial temperature increased the front temperature, which lead to more soluble oligomers and higher degree of crosslinking. The interplay of two opposite effects of oligomer and crosslinking determined the sol and gel content. An increase in tube size had two effects on the propagating front. One was to reduce heat loss. The other effect was to increase the number of escaping gas bubbles. The combined action of the two effects resulted in a maximum value of front temperature, an increase in sol content and a reduction in gel content with tube size. The highest swelling capacity of hydrogels was obtained when the initial temperature or tube size favored a formation of porous microstructure of hydrogels. [source]

Use of the Broselow Tape May Result in the Underresuscitation of Children

ACADEMIC EMERGENCY MEDICINE, Issue 10 2006
ACNP, Carolyn T. Nieman MSN
Abstract Objectives The purpose of this study was to determine the concordance of the Broselow tape with the measured heights and weights of a community-based population of children, especially in light of the increase in obesity in today's children. Methods The authors examined more than 7,500 children in a cross-sectional, descriptive study in two different cohorts of children to compare their actual weight with their predicted weight by a color-coded tape measure. Results In all patients, the percent agreement and , values of the Broselow color predicted by height versus the actual color by weight for the 2002A tape were 66.2% and 0.61, respectively. The concordance was best in infants, followed by school-age children, toddlers, and preschoolers (,= 0.66, 0.44, 0.39, and 0.39, respectively; percent agreement, 81.3%, 58.2%, 60.7%, and 64.0%, respectively). The tapes accurately predicted (within 10%) medication dosages for resuscitation in 55.3%,60.0% of the children. The number of children who were underdosed (by ,10%) exceeded those who were overdosed (by ,10%) by 2.5 to 4.4 times (p < 0.05). The tapes accurately predicted uncuffed endotracheal tube sizes when compared with age-based guidelines in 71% of the children, with undersizing (,0.5 mm) exceeding oversizing by threefold to fourfold (p < 0.05). Conclusions The Broselow tape color-coded system inaccurately predicted actual weight in one third of children. Caregivers need to take into consideration the accuracy of this device when estimating children's weight during the resuscitation of a child. [source]