Physiological modelling of agitation–sedation dynamics including endogenous agitation reduction

Sedation administration and agitation management are fundamental activities in any intensive care unit. A lack of objective measures of agitation and sedation, as well as poor understanding of the underlying dynamics, contribute to inefficient outcomes and expensive healthcare. Recent models of agitation-sedation pharmacodynamics have enhanced understanding of the underlying dynamics and enable development of advanced protocols for semi-automated sedation administration. However, these initial models do not capture all observed dynamics, particularly periods of low sedative infusion. A physiologically representative model that incorporates endogenous agitation reduction (EAR) dynamics is presented and validated using data from 37 critical care patients. High median relative average normalised density (RAND) values of 0.77 and 0.78 support and minimum RAND values of 0.51 and 0.55 for models without and with EAR dynamics respectively show that both models are valid representations of the fundamental agitation-sedation dynamics present in a broad spectrum of intensive care unit (ICU) patients. While the addition of the EAR dynamic increases the ability of the model to capture the observed dynamics of the agitation-sedation system, the improvement is relatively small and the sensitivity of the model to the EAR dynamic is low. Although this may represent a limitation of the model, the inclusion of EAR is shown to be important for accurately capturing periods of low, or no, sedative infusion, such as during weaning prior to extubation.

Combined endovenous laser therapy and ambulatory phlebectomy: refinement of a new technique

OBJECTIVE

Sclerotherapy (IS) or ambulatory phlebectomy (AP) are required as subsequent interventions in majority of cases following endovenous laser therapy (EVLT). We assessed whether AP performed concomitantly with EVLT (EVLTAP), is effective, acceptable, and reduces subsequent requirement for interventions.

METHOD

67 patients (70 limbs) with great saphenous varicosities underwent EVLTAP. Pain was assessed on days 1, 4 and 7 using a visual analogue scale (VAS) of 0 to 10. Clinical and ultrasound assessments were done at 1, 6 and 12 weeks (no ultrasound at 6 weeks). Residual varicosities underwent further AP or IS. Patients' satisfaction with the cosmetic outcome and overall treatment was assessed at 12 weeks using a VAS rating.

RESULTS

49 patients (70%) completed follow-up. Median pain scores were 1.6 (IQR 0.2-4.8), 0.3 (0-1.4) and 0.2 (0-1.1) on days 1, 4 and 7 respectively. Ultrasound demonstrated 69 (99%) and 47 (96%) occluded long saphenous veins at 1 and 12 weeks respectively. Subsequent IS or AP was performed on 3 (4%) or 1 (1%) limbs respectively. Cosmetic satisfaction was 9.6 (IQR 8.9-10) and overall satisfaction 9.8 (IQR 9.3-10).

CONCLUSION

EVLTAP produces excellent results, is feasible and acceptable, and obviates need for subsequent procedures in the short-term.

Fiber-optic color synthesizer

Full-color synthesis was achieved, for what we believe is the first time, utilizing a novel 3x1 hard polymer-clad fiber coupler along with red, green, and blue (RGB) LED primaries. By using RGB LEDs that are coupled to three input ports, the device rendered full color from the output port with a circular emitting pixel of 135 microm in diameter with an extended color gamut. The proposed fiber-optic color synthesizer can provide a compact waveguide solution for the beam scanning display and the tunable pure white source for LED backlighting.

Synchronous bifocal alveolar rhabdomyosarcoma

We report a case of bifocal rhabdomyosarcoma involving the hand and thigh in an 11-year-old female. We highlight the importance of a thorough clinical examination and an aggressive surgical approach in which each lesion is treated as a separate primary.

Hub colonization of central line catheters in children with cancer

18530

Background: Central venous catheter (CVC) hub sites provide bacterial access to the blood stream through migration along the external and internal surfaces of the catheter. Hub colonization rates vary from 29–38% in the adult literature. While pediatric studies were not found, one study reported the incidence of blood stream infections in neonates to be 30 times higher in catheters with hub colonization compared to catheter hubs that were not colonized. The purpose of this descriptive study was to obtain baseline cultures of CVC hubs to determine the incidence of colonization. Methods: Fifty-one catheter hub cultures were obtained from a convenience sample of 27 children with cancer. The mean age of the patients was 8.2 years (range 0.5–16.2 years); 77% were diagnosed with leukemia and 23% with solid tumors. Cultures were obtained by swabbing the threaded area of the catheter hub after removing the injection cap. A semi-quantitative culture for bacteria and fungus was obtained using standard laboratory procedures by a microbiologist. This study was conducted in a large urban hospital in the Southwest. Results: Fifty-seven percent of the hubs were culture positive. Of those positive cultures, 69%, 24%, 10% and 7% were colonized with 2, 3, 4 and 5 organisms, respectively. The most common organism cultured was coagulase negative staphylococcus. The only significant risk factor for this population was previous central venous catheter infections (p = 0.025). Sixty-nine percent of the lines were tunneled catheters. Central venous catheters were in place on an average of 75.3 days but this was not a factor in the colonization rate. Conclusions: The majority (57%) of the 51 central venous catheter hubs cultured were colonized with at least one organism. This study is the first to evaluate the rate of central venous catheter hub colonization in children with cancer. These findings support the need for more stringent guidelines for central venous catheter care. Further research evaluating the relationship between hub colonization and subsequent blood stream infection is needed.

No significant financial relationships to disclose.

Comprehensive analysis of UGT1A polymorphisms predictive for pharmacokinetics and treatment outcome in non-small cell lung cancer patients treated with irinotecan and cisplatin

13121

Purpose: To determine whether UGT1A1, UGT1A7, and UGT1A9 polymorphisms affect pharmacokinetics (PK) of irinotecan and treatment outcome of Korean patients with advanced non-small cell lung cancer (NSCLC). Methods: Eighty-one patients with advanced NSCLC were treated with irinotecan and cisplatin chemotherapy. Genomic DNA was extracted from peripheral blood and genotyped using direct sequencing. We analyzed the association of UGT1A genotypes with irinotecan PK and clinical outcomes. Results: In genotype-PK association analysis, UGT1A1*6/*6 (n = 6), UGT1A7*3/*3 (n = 6) and UGT1A9–118(dT)9/9 (n = 11) were associated with significantly lower AUCSN-38G/AUCSN-38 ratio (P = 0.002, 0.009and 0.001, respectively). In linkage disequilibrium (LD) analysis, the UGT1A7 variants were highly linked with UGT1A1*6 (D` = 0.85, r2 = 0.63) and UGT1A9*22 (D` = 0.95, r2 = 0.88), which was substantiated in haplotype analysis. Patients with UGT1A1*6/*6 had lower tumor response and higher incidence of severe neutropenia. UGT1A9–118(dT)9/9 also showed a trend for high incidence of severe diarrhea, but not tumor response. In survival analysis, patients with UGT1A1*6/*6 had significantly shorter progression-free survival (P = 0.001) and overall survival (P = 0.017). Conclusions: These findings suggest that UGT1A1*6 and UGT1A9*22 genotypes may be important for SN-38 glucuronidation and associated with irinotecan-related severe toxicity. Specifically, UGT1A1*6 might be useful for predicting tumor response and survival outcome of Korean patients with NSCLC treated with irinotecan-based chemotherapy. (Supported in part by NCC Grant 0210130 and 0510080 from National Cancer Center, Korea).

No significant financial relationships to disclose.

Early prediction of response in patients with advanced/metastatic non-small cell lung cancer during chemotherapy with FDG-PET-CT

13154

Background: To evaluate the use of 18-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) for prediction of response and survival early during the course of treatment in patients with advanced/metastatic NSCLC. Methods: Between May 2004 and November 2005, 31 patients (gender, 23M, 8F; stage, 2IIIB/29IV, histology, 6 squamous cell ca, 22 adenoca, 3 NOS; age median 57 (30–73 y)) with histopathologically proven NSCLC stage IIIB/IV were enrolled into this study. PET-CT was performed prior to and after one cycle of treatment. Early changes of primary tumor FDG-uptake measured by standardized uptake values (SUV) were correlated with best response to therapy as assessed by CT scan according to WHO response criteria. Results: Patients underwent standard treatment with gemcitabine/vinorelbine (15), gemcitabine/cisplatin (1) gemcitabine/vinorelbine/cisplatin (1), irinotecan/cisplatin (9) or gefitinib (5). In the 25 patients evaluable for response, other 6 patients ongoing, 9 patients achieved a partial response (36%), 5 showed stable diseases and 11 were progressive. Using a cut-off value of 20% reduction of FDG-uptake as a criterion for a response in PET-CT, subsequent best response was predicted with a sensitivity of 88.9% and a specificity of 87.5%. The positive predictive value of a metabolic response was 80.0% and the negative predictive value 93.3%, respectively. There was a significant correlation between the decrease of tumor metabolic activity and subsequent best response (p< 0.001). The median time to progression for PET-CT responder was 10.1 months when compared with that of non-responders with 2.6 months (log-rank p=0.009). Conclusions: Using FDG-PET best response to standard treatment and patient outcome can be predicted very early and therefore, the use of PET-CT may allow to reduce side effects and costs of ineffective therapy in non-responding patients

No significant financial relationships to disclose.