Outcome of selective non-operative management of penetrating abdominal injuries from the North American National Trauma Database

BACKGROUND

The aim of this study was to investigate trends in the practice of selective non-operative management (SNOM) for penetrating abdominal injury (PAI) and to determine factors associated with its failure.

METHODS

The National Trauma Data Bank for 2002-2008 was reviewed. Patients with PAI were categorized as those who underwent successful SNOM (operative management not required) and those who failed SNOM (surgery required more than 4 h after admission). Yearly rates of SNOM versus non-therapeutic laparotomy (NTL) were plotted. Multivariable regression analysis was performed to identify factors associated with failed SNOM and mortality.

RESULTS

A total of 12 707 patients with abdominal gunshot and 13 030 with stab wounds were identified. Rates of SNOM were 22.2 per cent for gunshot and 33.9 per cent for stab wounds, and increased with time (P < 0.001). There was a strong correlation between the rise in SNOM and the decline in NTL (r = - 0.70). SNOM failed in 20.8 and 15.2 per cent of patients with gunshot and stab wounds respectively. Factors predicting failure included the need for blood transfusion (odds ratio (OR) 1.96, 95 per cent confidence interval 1.11 to 3.46) and a higher injury score. Failed SNOM was independently associated with mortality in both the gunshot (OR 4.48, 2.07 to 9.70) and stab (OR 9.83, 3.44 to 28.00) wound groups.

CONCLUSION

The practice of SNOM is increasing, with an associated decrease in the rate of NTL for PAI. In most instances SNOM is successful; however, its failure is associated with increased mortality. Careful patient selection and adherence to protocols designed to decrease the failure rate of SNOM are recommended.

Toxicological studies on 2,4,6-tribromoanisole

TBA, or 2,4,6-tribromoanisole, is a musty-smelling metabolite of 2,4,6-tribromophenol that is used as a flame retardant and an antifungal agent for wooden pallets and packaging materials. The compound can impart its peculiar, often offensive, odor on product packaging to the concern of consumers for the safety of the package contents. These studies were conducted to evaluate the safety of TBA to humans ingesting products tainted with TBA. In addition to the 28-day oral study, a bacterial reverse mutation study was conducted, and confirmed that TBA was not mutagenic. To evaluate oral safety, TBA was evaluated in single dose and 5-day and 4-week repeated dose oral toxicity studies in rats. The test article, administered in single gavage doses of 2000, 5000 and 7500 mg/kg body weight (bw), in 5 daily repeated doses of 1000, 2000 or 3000 mg/kg bw/day or in 28 daily oral gavage doses of 0 001, 0.01, 100, and 1000 mg/kg bw/day did not result in any deaths. Also, the single and repeat dose studies resulted in no significant differences between control and treated groups on body weight gain, food consumption, clinical observations, blood biochemical values, and hematology findings. Treatment-related adverse findings were only detected in male rats during repeated dose studies and were associated with high plasma concentrations of TBA. The test article-related finding of hyaline droplets in the cortical tubular epithelium of kidneys was associated with increases in α(2 μ)-globulin content in the kidneys as indicated by the intensity of immunohistochemical staining. These findings were correlated with an increased weight of kidneys in males administered 1000mg/kgbw/day for 28days. Chemical induction of hyaline droplets containing α(2μ)-globulin in the renal proximal tubule is a process unique to the male rat and is not relevant for human risk assessment. Findings of increased liver weight with minimal centrilobular to diffuse hepatocellular hypertrophy in males treated with TBA at 1000mg/kg bw/day for 28days were considered to be an adaptive metabolic response to xenobiotic administration. The increased volume of urine, noted in both males and females treated with 1000mg/kg bw/day was considered adaptive and necessary to excrete the high xenobiotic burden resulting from TBA administration. TBA appeared to be highly bioavailable since high concentrations of TBA were detected in plasma, at 1, 4 and 8h after administration of TBA at 100 and 1000mg/kg bw for 1 and 28days. Levels were dose-related but did not clarify the course of TBA elimination with time after administration. These studies indicate that TBA, administered orally to rats, produced male rat-specific, treatment-related toxicity at the highest orally administered dose in repeated dose (5-day at 3000mg/kg bw and 28-day at 1000mg/kg bw) studies. Therefore, the NOAEL for the 28-day oral study was determined to be 1000mg/kg bw/day for the rat.

Neural progenitor potential in cultured Müller glia: effects of passaging and exogenous growth factor exposure

The Müller radial glial cell is the principal support cell of the adult mammalian retina. Recent reports suggest that these cells retain the capacity to proliferate, express phenotypes reminiscent of retinal progenitor cells (RPC) and generate neuron-like progeny. We isolated rodent Müller cells and generated cultures that could be passaged under conditions used in neural stem/progenitor cell colonies. We demonstrate that during the early period of primary culture, Müller glia proliferate into sphere colonies and express a select regimen of phenotypes normally seen in RPCs. This effect correlates temporally with the loss of retinal neurons post-dissection. When chronically maintained in vitro, Müller cells can be repeatedly passaged, and up-regulate early RPC phenotypes that are suggestive of cellular de-differentiation. Furthermore, exposure of Müller glial cultures to differentiating conditions containing growth factors stimulates Müller glia to up-regulate phenotypes associated with retinal neurons. These data provide further evidence that isolated, adult Müller glia retain functional and phenotypic features of RPCs.

Synthesis and incorporation of a simple acyclic furan containing phosphoramidite

A novel furan containing phosphoramidite was synthesized and incorporated into model oligonucleotides. This glycol nucleic acid based building block contains a furan unit substituting the natural base, and can be used for post synthetic oligonucleotide modifications by orthogonal chemistries such as Schiff base formation after in situ oxidation or Diels-Alder cycloadditions.

A common variant of the interleukin 6 receptor (IL-6r) gene increases IL-6r and IL-6 levels, without other inflammatory effects

Interleukin-6 (IL-6) is a key inflammatory cytokine, signalling to most tissues by binding to a soluble IL-6 receptor (sIL-6r), making a complex with gp130. We used 1273 subjects (mean age 68 years) from the InCHIANTI Italian cohort to study common variation in the IL-6r locus and associations with interleukin 6 receptor (IL-6r), IL-6, gp130 and a battery of inflammatory markers. The rs4537545 single nucleotide polymorphism (SNP) tags the functional non-synonymous Asp358Ala variant (rs8192284) in IL-6r (r(2)=0.89, n=343). Individuals homozygous for the rs4537545 SNP minor allele (frequency 40%) had a doubling of IL-6r levels (132.48 pg/ml, 95% CI 125.13-140.27) compared to the common allele homozygous group (68.31 pg/ml, 95% CI 65.35-71.41): in per allele regression models, the rs4537545 SNP accounted for 20% of the variance in sIL-6r, with P=5.1 x 10(-62). The minor allele of rs4537545 was also associated with higher circulating IL-6 levels (P=1.9 x 10(-4)). There was no association of this variant with serum levels of gp130 or with any of the studied pro- and anti-inflammatory markers. A common variant of the IL-6r gene results in major changes in IL-6r and IL-6 serum levels, but with no apparent effect on gp130 levels or on inflammatory status in the general population.

Common genetic variation in the gene encoding interleukin-1-receptor antagonist (IL-1RA) is associated with altered circulating IL-1RA levels

Interleukin-1-receptor antagonist (IL-1RA) modulates the biological activity of the proinflammatory cytokine interleukin-1 (IL-1) and could play an important role in the pathophysiology of inflammatory and metabolic traits. We genotyped seven single nucleotide polymorphisms (SNPs) that capture a large proportion of common genetic variation in the IL-1RN gene in 1256 participants from the Invecchiare in Chianti study. We identified five SNPs associated with circulating IL-1RA levels with varying degrees of significance (P-value range=0.016-4.9 x 10(-5)). We showed that this association is likely to be driven by one haplotype, most strongly tagged by rs4251961. This variant is only in weak linkage disequilibrium (r(2)=0.25) with a previously reported variable number of tandem repeats polymorphism (VNTR) in intron-2 although a second variant, rs579543, that tags the VNTR (r(2)=0.91), may also be independently associated with IL-1RA levels (P=0.03). We found suggestive evidence that the C allele at rs4251961 that lowers IL-1RA levels is associated with an increased IL-1beta (P=0.03) level and may also be associated with interferon -gamma (P=0.03), alpha-2 macroglobulin (P=0.008) and adiponectin (P=0.007) serum levels. In conclusion, common variation across the IL-1RN gene is strongly associated with IL-1RA levels.

An evaluation of the clinical and cost-effectiveness of pulmonary artery catheters in patient management in intensive care: a systematic review and a randomised controlled trial

OBJECTIVES

To evaluate the clinical and cost-effectiveness of managing critically ill patients in adult, general intensive care with or without pulmonary artery catheters (PACs).

DESIGN

An open, multi-centre, randomised controlled trial with economic evaluation (cost-utility and cost-effectiveness analysis).

SETTING

The setting was general (mixed medical/surgical) intensive care units (ICUs) in the UK admitting adults.

PARTICIPANTS

Adult patients in participating ICUs deemed by the responsible treating clinician to require management with a PAC.

INTERVENTIONS

These were insertion of a PAC and subsequent clinical management, at the discretion of the responsible treating clinicians, using data derived from the PAC. The control group were managed without a PAC but with the option of using alternative cardiac output monitoring devices.

MAIN OUTCOME MEASURES

The main outcome measure was hospital mortality. Secondary outcome measures were length of stay in the ICU, length of stay in an acute hospital and organ-days of support in the ICU. For the economic evaluation, the main outcome measure was quality-adjusted life-years (QALYs) and the secondary outcome measure was hospital mortality.

RESULTS

Sixty-five ICUs in the UK participated. Of these, 43 (66%) used alternative cardiac output monitoring devices in control group patients. A total of 1263 patients were identified as being eligible for the trial. Of these, 1041 (82.4%) were randomised and allocated to management with (n = 519) or without (n = 522) a PAC. There were no losses to follow-up. However, 27 patients (13 in the PAC group and 14 in the control group) were withdrawn from the trial because either the patient withdrew consent on recovering mental competency or the relatives withdrew agreement following randomisation. Data on 1014 patients were included in the analysis. Participants in the two groups had similar baseline characteristics. There was no difference in hospital mortality for patients managed with (68.4%) or without (65.7%) a PAC. The adjusted hazard ratio (PAC versus no PAC) was 1.09 [95% confidence interval (CI) 0.94 to 1.27]. There was no difference in the median length of stay in ICU, the median length of stay in an acute hospital or mean organ-days of support in ICU between the two groups. The economic evaluation found that the expected cost per QALY gained from the withdrawal of PAC was 2985 pounds. The expected cost per life gained from the withdrawal of PAC was 22,038 pounds.

CONCLUSIONS

Clinical management of critically ill patients with a PAC, as currently practised in the UK, neither improves hospital survival for adult, general intensive care patients nor reduces length of stay in hospital. The lack of demonstrable benefit from a device previously believed to be beneficial could be explained by statistical chance, by misinterpretation of PAC-derived data, by ineffective treatment strategies based on data correctly interpreted using the current paradigm or by subsequent inaction following insertion of the device. It is also possible that detailed data on haemodynamics, however used, cannot modify the disease process sufficiently to influence disease outcome. The economic evaluation, using decision analysis techniques rather than conventional hypothesis testing, suggests that the withdrawal of the PAC from routine clinical practice in the NHS would be considered cost-effective in the current decision-making climate, and might result in lives or life-years being saved at modest cost. With the declining use of PACs in the UK and the findings of this report indicating no overall benefit from management with a PAC, it should now be possible to examine protocolised management with a PAC in selected groups of critically ill patients against appropriate controls, something that was difficult while PACs were the considered standard of care.

Power Doppler ultrasound of rheumatoid synovitis: quantification of therapeutic response

The aim of this study is to quantify power Doppler assessment of therapeutic response in rheumatoid synovitis. 13 patients (6 male, 7 female) with rheumatoid arthritis, who had an acute exacerbation of small joint synovitis in the hands, were examined with quantitative power Doppler, before and after intravenous corticosteroid treatment. All patients were examined by a single radiologist, using an ATL HDI 5000 ultrasound machine (ATL, Boswell). The images were analysed using a specially developed software package (HDI Lab), which quantifies power Doppler signal. All patients improved clinically following treatment, which was reflected in functional disability scores, and in the C-reactive protein levels and erythrocyte sedimentation rate. In all cases, there was a significant decrease in synovial vascularity as measured by the mean amplitude of signal on quantitative power Doppler. Quantitative power Doppler may allow objective assessment of treatment in small joint synovitis.