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.

Reforestation of agricultural land in the tropics: The relative contribution of soil, living biomass and debris pools to carbon sequestration.

Tropical regions of the world experience high rates of land-use change and this has a major influence on terrestrial carbon (C) pools and the global C cycle. We assessed land-use change from agriculture to reforested plantings (with endemic species), up to 33 years of age, using 10 paired sites in the wet tropics, Australia. We determined the impacts on 0-50 cm below-ground C (soil organic C (SOC), charcoal C, humic organic C, particulate organic C, resistant organic C), C stored in roots (fine and coarse), C stored in living above-ground biomass and debris C pools. Reforested areas accumulated ecosystem C at a rate of 7.4 Mg ha-1 yr-1. Reforestation plantings contained, on average, 2.3 times more ecosystem C than agricultural areas (102 Mg ha-1 and 233 Mg ha-1, respectively). Most of the C accumulation was in living above-ground and below-ground biomass (60 and 30%, respectively) with a smaller amount in debris pools (16%). Apart from C in roots, soil C accumulation was not obvious across sites ranging from 8 to 33 years since reforestation, relative to the agricultural baseline. Differences in SOC (and associated SOC pools) to a depth of 50 cm, did exist between reforested areas and adjacent agriculture at some sites, however there was not a consistent trend in SOC associated with reforestation. Local site-based factors (e.g. soil texture and mineralogy, land-use history and microbial activity) appear to have a strong influence on the direction of the change in SOC. While reforestation in the tropics has great potential to accumulate C in biomass in living vegetation, and debris pools, it is likely to take approximately 50 years before C stocks of reforested areas resemble natural ecosystems. Accumulation of SOC through reforestation is difficult to achieve, highlighting the need to conserve carbon pools in remnant forests in the tropics.

Host tree influences on longicorn beetle (Coleoptera: Cerambycidae) attack in subtropical Corymbia (Myrtales: Myrtaceae).

Phoracantha longicorn beetles are endemic to Australia, and some species have become significant pests of eucalypts worldwide, yet little is known about their host plant interactions and factors influencing tree susceptibility in Australia. Here, we investigate the host relationships of Phoracantha solida (Blackburn, 1894) on four eucalypt taxa (one pure species and three hybrid families), examining feeding site physical characteristics including phloem thickness, density, and moisture content, and host tree factors such as diameter, height, growth, taper, and survival. We also determine the cardinal and vertical (within-tree) and horizontal (between-tree) spatial distribution of borers. Fewer than 10% of P. solida attacks were recorded from the pure species (Corymbia citriodora subsp. variegate (Hook)), and this taxon also showed the highest survival, phloem thickness, relative growth rate, and bark:wood area. For the two most susceptible taxa, borer severity was negatively correlated with moisture content, and positively related to phloem density. Borers were nonrandomly and nonuniformly distributed within trees, and were statistically aggregated in 32% of plots. More attacks were situated on the northern side of the tree than the other aspects, and most larvae fed within the lower 50 cm of the bole, with attack height positively correlated with severity. Trees with borers had more dead neighbors, and more bored neighbors, than trees without borers, while within plots, borer incidence and severity were positively correlated. Because the more susceptible taxa overlapped with less susceptible taxa for several physical tree factors, the role of primary and secondary chemistries in determining host suitability needs to be investigated. Nevertheless, taxon, moisture content, phloem density, tree size, and mortality of neighboring trees appeared the most important physical characteristics influencing host suitability for P. solida at this site.

Time-dependent perioperative anesthetic management and outcomes of the first 100 consecutive cases of spring-assisted surgery for sagittal craniosynostosis.

BACKGROUND: The anesthetic risks and outcomes of the first 100 consecutive spring-assisted surgeries (SAS) for cranial expansion from a single institution are reported. The effect of number of procedures was also tested on hematocrit postoperative day 1 (POD1), anesthesia time, and surgery time of the first procedure. METHODS: The records of 100 consecutive patients undergoing SAS were reviewed. Anesthesia management and related complications are presented. Time series linear regression analysis was performed on hematocrit POD1, anesthesia time, and surgery time of the first procedure. RESULTS: The average age of the first insertion procedure was 4.4 and 9.0 months for the second removal procedure. Two patients were inadvertently extubated during positioning. Thirty-eight children had a decrease in blood pressure >20% from baseline. No child was admitted to the intensive care unit. No patient received any blood or blood product transfusion. Anesthesia time, surgery time, and hematocrit POD1 were correlated with procedure number or experience. CONCLUSIONS: Changes in anesthetic management resulted from changing the procedure. The reduction in volume resuscitation reduces the need for invasive monitoring. Facility and comfort with the surgical procedure increase with time and number of procedures performed. This experience further reduces blood loss and risk of transfusion.

Video-assisted ductal ligation in premature infants.

BACKGROUND: Video-assisted thoracic surgery has been shown to be a safe and effective method of closing the patent ductus arteriosus in infants and children. We have applied this technique in low birth weight premature infants and now report our experience. METHODS: Since 1996, we have used video-assisted thoracic surgery ligation as the treatment of choice for all patent ductus arteriosus, including 100 performed on premature infants (23 to 31 weeks' gestation, mean 25.6 weeks; 0.420 to 1.5 kg, mean 0.859 kg). A modification of our previously described technique was used with a three-port approach. All patients had some degree of symptoms of congestive failure with failure to wean from ventilatory support or oxygen dependency. Five infants had associated patent foramen, and 1 had a small ventricular septal defect. RESULTS: All 100 procedures were performed in the operating room. One infant was found to have a coarctation, and the procedure was aborted. The remaining 99 were successfully ligated, although three were converted to an open procedure (3%) because of coagulopathy, poor pulmonary compliance, or hemodynamic instability. There were no procedure-related deaths; however, 15 infants subsequently died of complications of prematurity, including enterocolitis, sepsis, and late respiratory failure. Six infants had chest tubes left in place for coagulopathy, effusions, suspected air leak, and existing empyema. There were six residual pneumothoraces, four requiring treatment. CONCLUSIONS: Video-assisted thoracic surgery is a safe and effective technique for patent ductus arteriosus ligation in premature infants, including those with very low and extremely low birth weight.

Surgical advancement influences perioperative care: a comparison of two surgical techniques for sagittal craniosynostosis repair.

Methods for surgical correction of sagittal craniosynostosis have progressed. The hypothesis is that advances in surgical interventions for craniosynostosis affect perioperative anesthetic care. We reviewed the records of eight children who underwent cranial vault reconstruction (CVR) and nine who underwent spring-mediated cranial expansion (SME) for sagittal craniosynostosis. We compared the data from the CVR procedure to data from the combined procedures for SME (insertion and removal of springs). Anesthesia times were similar between the CVR (4 h 24 min) and the combined SME (4 h 27 min) groups, whereas surgical times were different between the CVR (3 h 25 min) and combined SME groups (2 h 21 min) (P = 0.002). Length of stay was 4.1 days for the CVR group (confidence interval [CI], 3.8-4.4 days) versus 3.1 days (CI, 2.9-3.4 days) in the combined SME group (P = 0.0001). Blood loss was significantly less in the combined SME group at 48 mL (CI, 29-83 mL) compared with the CVR group at 291 mL (CI, 230-352 mL). All eight patients in the CVR group received blood with a mean of 1.4 U (range, 1-2 U). No SME patient received any blood products. The reduction in blood loss with this new surgical treatment is significant for the patient in reducing blood transfusion and for the anesthesiologist in reducing concerns of volume resuscitation.