Assessment of Common Criteria for Awake Extubation in Infants and Young Children.

BACKGROUND: Practice patterns surrounding awake extubation of pediatric surgical patients remain largely undocumented. This study assessed the value of commonly used predictors of fitness for extubation to determine which were most salient in predicting successful extubation following emergence from general anesthesia with a volatile anesthetic in young children. METHODS: This prospective, observational study was performed in 600 children from 0 to 7 yr of age. The presence or absence of nine commonly used extubation criteria in children were recorded at the time of extubation including: facial grimace, eye opening, low end-tidal anesthetic concentration, spontaneous tidal volume greater than 5 ml/kg, conjugate gaze, purposeful movement, movement other than coughing, laryngeal stimulation test, and oxygen saturation. Extubations were graded as Successful, Intervention Required, or Major Intervention Required using a standard set of criteria. The Intervention Required and Major Intervention Required outcomes were combined as a single outcome for analysis of predictors of success. RESULTS: Successful extubation occurred in 92.7% (556 of 600) of cases. Facial grimace odds ratio, 1.93 (95% CI, 1.03 to 3.60; P = 0.039), purposeful movement odds ratio, 2.42 (95% CI, 1.14 to 5.12; P = 0.022), conjugate gaze odds ratio, 2.10 (95% CI, 1.14 to 4.01; P = 0.031), eye opening odds ratio, 4.44 (95% CI, 1.06 to 18.64; P= 0.042), and tidal volume greater than 5 ml/kg odds ratio, 2.66 (95% CI, 1.21 to 5.86; P = 0.015) were univariately associated with the Successful group. A stepwise increase in any one, in any order, of these five predictors being present, from one out of five and up to five out of five yielded an increasing positive predictive value for successful extubation of 88.3% (95% CI, 82.4 to 94.3), 88.4% (95% CI, 83.5 to 93.3), 96.3% (95% CI, 93.4 to 99.2), 97.4% (95% CI, 94.4 to 100), and 100% (95% CI, 90 to 100). CONCLUSIONS: Conjugate gaze, facial grimace, eye opening, purposeful movement, and tidal volume greater than 5 ml/kg were each individually associated with extubation success in pediatric surgical patients after volatile anesthetic. Further, the use of a multifactorial approach using these predictors, may lead to a more rational and robust approach to successful awake extubation.

An initial experience with an Extraluminal EZ-Blocker® : A new alternative for 1-lung ventilation in pediatric patients.

BACKGROUND: The need for 1-lung ventilation in school age, pediatric patients is uncommon and as a result there are relatively few devices available to facilitate lung isolation in this population. Furthermore, little is known about the efficacy and techniques of placement of the currently available devices. One of the newest devices available that may be appropriate in this age group is the EZ-Blocker. AIMS: We aimed to examine our initial experience with the EZ-Blocker to evaluate the performance of this device with respect to potential improvements in technique and patient selection going forward. METHODS: We performed a retrospective chart review of all pediatric patients who underwent 1-lung ventilation with an EZ-Blocker since the blocker became available at our institution. We recorded demographics, details of placement, intraoperative course, number of repositions, and any postoperative morbidity related to blocker placement or 1-lung ventilation. RESULTS: We were able to correctly place the EZ-Blocker and achieve lung isolation in 8 of 11 patients. There was a single episode of repositioning required during 1-lung ventilation with an EZ-Blocker. CONCLUSION: The EZ-Blocker was successful in providing lung isolation for a majority of our school age patients. Size constraints in children <6 years of age, excessive secretions, and distortions of tracheal anatomy seemed to be the greatest hindrances to successful placement and positioning of the device. Once correctly positioned, however, the EZ-Blocker may be more stable than the Arndt endobronchial blocker.

Specific dermatological benefits associated with quantities of lotion transferred to the skin.

BACKGROUND: A growing number of manufacturers are taking advantage of the ability of absorbent consumer products to deliver lotion to the skin. The lotion is included on these products to help protect the skin from adverse skin effects that can occur, including: (1) irritation, (2) over hydration of the stratum corneum, (3) dryness that can occur from extended exposure to highly absorbent consumer products, and (4) changes in pH. OBJECTIVE: This manuscript presents results of a quantitative lotion transfer study of adult incontinence products. Resulting lotion transfer is compared to the results of several separate experiments in which specific skin benefits have been correlated to lotion concentrations. METHODS: The behind-the-knee (BTK) lotion transfer protocol was used to quantitate lotion transfer from adult incontinence (AI) test products constructed using 2 lotion formulations and 2 configurations of lotion application. A modified arm patch protocol, in which skin sites of a measured dimension were pre-treated with specific volumes of lotion, was used to evaluate protective effects of lotion against exposure to irritants, and over hydration from wetted absorbent products. RESULTS: After a 6-hours continuous exposure in the BTK the 5-stripe lotion configuration products transferred (adjusted mean ± SE) 94 ± 11-104 ± 11 µg/cm2 lotion. After 24 hours of wear, transfer had increased to 127 ± 22 and 149 ± 24 µg/cm2 , respectively. The single-block configuration products transferred 289 ± 10-316 ± 10 µg/cm2 (P = .04). Transfer after 24 hours of wear was 328 ± 23 and 472 ± 21 µg/cm2 , respectively (P < .0001). Several protocols were used to evaluate the concentration of lotion required to provide four specific skin benefits. In studies evaluating protection against irritants, skin site pre-treated with lotion were patched with 0.5% sodium lauryl sulfate (SLS). Protective effects were assessed by visual assessment of erythema and trans-epidermal water loss (TEWL). In the first experiment, lotion pre-treatment concentrations as low as 165 µg/cm2 exhibited significantly (P < .05) lower erythema and TEWL compared to the positive irritant control (ie, no lotion pre-treatment and SLS only). In the second experiment, lotion pre-treatment concentrations of 80 µg/cm2 (P = .018) exhibited significantly (P = .018) lower TEWL. In two studies on protection from over hydration, lotion pre-treatment sites were subsequently patched with wetted absorbent consumer products. The change in TEWL was used as a measure of over hydration. Lotion concentrations significantly reduced the increase in TEWL at 80 µg/cm2 (P = .007) and 70 µg/cm2 (P ≤ .05). A BTK study was used to evaluate the ability of lotion to prevent dryness. After 6 hours of wear, test products transferring lotion concentrations of 110 or 133 µg/cm2 produced significantly lower scores for dryness compared to products transferring 48 or 69 µg/cm2 . Using collagen sheets to mimic the stratum corneum, an in vitro study was conducted to measure the ability of lotion to prevent passage of high pH buffer solution. Results demonstrated that the lowest concentration of lotion that was tested (110 µg/cm2 ) interfered with passage of the high pH buffer through the collagen sheet, delaying the rise in pH. CONCLUSIONS: We can conclude that pretreatment with 110 µg/cm2 lotion acts as a barrier to high pH fluids such as urine. Using the measurement of lotion transfer from the AI products, together with the results of studies conducted to determine the concentration of lotion required to provide specific skin benefits, we conclude that the five-stripe lotion configuration AI test products transferred enough lotion (ie, ≥80 µg/cm2 ) to provide skin protection with regard to: (1) irritant effects and (2) excess moisture. The single-block AI test products also transferred enough lotion to provide these skin benefits (ie, ≥165 µg/cm2 ), and the additional benefits of skin protection against: (3) dryness, and (4) changes in pH.

Setting the Record Straight on Diaper Rash and Disposable Diapers.

Skin in the diapered area is continuously threatened by exposure to changes in pH levels, overhydration, mechanical friction, and fecal enzymes, making diaper rash a common occurrence among babies. Up to one third of infants may exhibit clinical symptoms of diaper rash at any time, and more than half of babies between the ages of 4 and 15 months develop diaper rash at least once in a 2-month period. Despite misperceptions that disposable diapers are related to an increase in diaper rash, the incidence of diaper dermatitis is on the decline, largely due to significant improvements in disposable diaper construction and materials. Modern-day disposable diapers are specifically designed to limit exposure to irritants in the diaper area, reduce overhydration, inhibit skin barrier compromise, and help maintain normal skin pH levels and have been thoroughly evaluated for safety and skin compatibility.

Staining of proteins in gels with Coomassie G-250 without organic solvent and acetic acid.

In classical protein staining protocols using Coomassie Brilliant Blue (CBB), solutions with high contents of toxic and flammable organic solvents (Methanol, Ethanol or 2-Propanol) and acetic acid are used for fixation, staining and destaining of proteins in a gel after SDS-PAGE. To speed up the procedure, heating the staining solution in the microwave oven for a short time is frequently used. This usually results in evaporation of toxic or hazardous Methanol, Ethanol or 2-Propanol and a strong smell of acetic acid in the lab which should be avoided due to safety considerations. In a protocol originally published in two patent applications by E.M. Wondrak (US2001046709 (A1), US6319720 (B1)), an alternative composition of the staining solution is described in which no organic solvent or acid is used. The CBB is dissolved in bidistilled water (60-80 mg of CBB G-250 per liter) and 35 mM HCl is added as the only other compound in the staining solution. The CBB staining of the gel is done after SDS-PAGE and thorough washing of the gel in bidistilled water. By heating the gel during the washing and staining steps, the process can be finished faster and no toxic or hazardous compounds are evaporating. The staining of proteins occurs already within 1 minute after heating the gel in staining solution and is fully developed after 15-30 min with a slightly blue background that is destained completely by prolonged washing of the stained gel in bidistilled water, without affecting the stained protein bands.

Simplified screening for the detection of soluble fusion constructs expressed in E. coli using a modular set of vectors.

BACKGROUND: The solubility of recombinant proteins expressed in bacteria is often disappointingly low. Several strategies have been developed to improve the yield and one of the most common strategies is the fusion of the target protein with a suitable partner. Despite several reports on the successful use of each of these carriers to increase the solubility of some recombinant proteins, none of them was always successful and a combinatorial approach seems more efficient to identify the optimal combination for a specific protein. Therefore, the efficiency of an expression system critically depends on the speed in the identification of the optimal combination for the suitable fusion candidate in a screening process. This paper describes a set of expression vectors (pETM) designed for rapid subcloning, expression and subsequent purification using immobilized metal affinity chromatography (IMAC). RESULTS: A single PCR product of two Yellow Fluorescent Proteins (EYFPs) was cloned into 18 vectors comprising identical restriction sites and varying fusion partners as well as differing protease recognition sites. After a small-scale expression, the yields of the different constructs were compared using a Coomassie stained SDS-polyacrylamide gel and the results of this preliminary screening were then confirmed by large-scale purification. The yields were calculated and the stability of the different constructs determined using three independent conditions. The results indicated a significant correlation between the length and composition of non-native amino acid tails and stability. Furthermore, the buffer specificity of TEV and 3C proteases was tested using fusion proteins differing only in their protease recognition sequence, and a His-GST-EYFP construct was employed to compare the efficiency of the two alternative affinity purification methods. CONCLUSION: The experiments showed that the set of pETM vectors could be used for the rapid production of a large array of different constructs with specific yield, stability, and cleavage features. Their comparison allowed the identification of the optimal constructs to use for the large-scale expression. We expect that the approach outlined in this paper, i.e. the possibility to obtain in parallel fusion products of the target protein with different partners for a preliminary evaluation, would be highly beneficial for all them who are interested in the rapid identification of the optimal conditions for protein expression.