Adrenal status in children with septic shock using low-dose stimulation test.

OBJECTIVES: There is paucity of data on the magnitude of absolute or relative adrenal insufficiency in septic shock, especially in children. We conducted a prospective study to determine the prevalence of adrenal insufficiency in children with septic shock using a low-dose Synacthen (1 microg) stimulation test. DESIGN: Cross-sectional study. SETTING: Pediatric intensive care unit in a tertiary care hospital in northern India. PATIENTS: Children with septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We performed cortisol estimation at baseline and after low-dose Synacthen (1 microg) stimulation at 30 and 60 mins in children with fluid refractory septic shock admitted to our pediatric intensive care unit. Basal cortisol levels <7 microg/dL and peak cortisol level <18 microg/dL were used to define adrenal insufficiency. An increment of <9 microg/dL after stimulation was used to diagnose relative adrenal insufficiency. As there is lack of consensus on the cutoffs for defining relative adrenal insufficiency using the low-dose adrenocorticotropic hormone test, we evaluated different cutoff values (increment at 30 mins, increment at 60 mins, greater of the two increments) and evaluated their association with the incidence of catecholamine refractory shock and outcomes. Children with sepsis but without septic shock were sampled for baseline cortisol levels as a comparison. Thirty children (15 girls) with septic shock were included; median age (95% confidence interval) was 36.5 (9.39- 58.45) months. Median Pediatric Risk of Mortality score was 22.5 (14.13-24.87). Fifteen (50%) children survived. The median (95% confidence interval) cortisol values at baseline and 30 mins and 60 mins after stimulation were 71 (48.74-120.23) microg/dL, 78.1 (56.9-138.15) microg/dL, and 91 (56.17-166.44) microg/dL, respectively. The median baseline cortisol value in age- and gender-matched children with sepsis was 11.5 microg/dL. None of the children with septic shock fulfilled the criteria for absolute adrenal insufficiency. However, nine (30%) patients had relative adrenal insufficiency (increment in cortisol <9 microg/dL). Of these nine patients, five (56%) died; of the 21 patients with a greater increment in cortisol after stimulation, ten died (p = .69). Compared with patients in septic shock with normal adrenal reserve, those with relative adrenal insufficiency had a higher incidence of catecholamine refractory shock (p = .019) but no difference in mortality rate (p = .69). On the sensitivity and specificity analysis using various cutoffs of increment, the best discrimination for catecholamine refractory shock was obtained with a peak increment <6 microg/dL. CONCLUSIONS: Relative adrenal insufficiency is common in children with septic shock and is associated with catecholamine refractory shock.     

Stigmasterol as internal standard for simultaneous quantitation of biliary cholesterol and bile acids by gas-liquid chromatography

The use of stigmasterol (a plant sterol not encountered in bile) as an internal standard during the simultaneous quantitation of biliary cholesterol and individual bile acids by gas-liquid chromatography is described.     

Association between lymphotoxin alpha (-252 A/G and -804 C/A) gene polymorphisms and risk of stroke in North Indian population: a hospital-based case-control study

Purpose: Lymphotoxin alpha (LTA), a proinflammatory cytokine, plays an important role in promoting atherosclerosis which is an independent risk factor for stroke. Recent genetic studies have suggested that polymorphisms in the LTA gene, which affect its expression and biological function, may contribute to the development of stroke. The aim of this case-control study was to determine the association between LTA (-252 A/G and -804 C/A) gene polymorphisms and risk of stroke. Methods: Genotyping was determined by using SNaPshot method for 250 ischemic stroke (IS) patients, 250 age and sex matched IS free controls, 100 intracerebral hemorrhage (ICH) patients and 100 age and sex matched ICH free controls. Conditional logistic regression analysis with adjusting multiple demographic and risk factor variables was used to calculate the strength of association between LTA (-252 A/G and -804 C/A) gene polymorphisms and risk of stroke. The linkage disequilibrium (LD) was analyzed by using HaploView 4.2 software. Results: The distribution of LTA (-252 A/G and -804 C/A) genotypes was consistent with Hardy–Weinberg equilibrium. Adjusted conditional logistic regression analysis showed no significant association between LTA (-252 A/G and -804 C/A) gene polymorphisms and risk of both IS and ICH. Based on Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification, a significant association between LTA -252 A/G gene polymorphism and small vessel disease subtype of IS under dominant model (OR, 2.06; 95% CI, 1.03–4.12; p value 0.04) with the risk of IS was observed. No LD was observed for both single nucleotide polymorphisms (SNPs) in north Indian population. Conclusion: Neither -252 G/A nor -804 C/A polymorphism of the LTA gene was found to be associated with overall stroke as well as any subtype of IS excluding SVD in North Indian population.     

Syncope: Review of Monitoring Modalities

Elucidating the underlying cause of unexplained syncope, palpitations or other possible arrhythmia-related symptoms is a formidable clinical challenge. Cardiac monitoring supplements the most important “test” in patients with syncope or palpitations, that of a thoughtful history and physical examination. Ideally, comprehensive physiologic monitoring during spontaneous symptoms would constitute what, at present, is an unattainable gold standard test for establishing a cause. Short of that goal, establishing an accurate symptom-rhythm correlation can often provide a diagnosis. Ambulatory outpatient monitoring is a powerful diagnostic tool for the evaluation of cardiac arrhythmias. Evolving technologies have provided a vast array of monitoring options for patients suspected of having cardiac arrhythmias, with each modality differing in duration of monitoring, quality of recording, convenience and invasiveness. Holter monitors, event monitors and external loop recorders are non-invasive and provide easily accessible short-term monitoring solutions. In instances where the diagnosis remains elusive, a more long-term strategy with an implantable loop recorder may be the preferred path.     

Limb conservation in extremity soft tissue sarcomas with vascular involvement

Background:

The major neurovascular involvement and large primary tumors are indication of amputation. The present study is an attempt to explore the feasibility of a limb salvage surgery in extremity sarcoma cases with major vessel involvement. Oncological outcomes and surgery-related morbidities are compared with those reported in literature.

Materials and Methods:

A retrospective review of all limb salvage surgeries done in our department between 2005 and 2008 was done and four cases of extremity sarcoma of lower limb involving femoral vessels analyzed. Interpretation of data from these cases, along with review of literature, is done.

Results:

In all these cases a wide monobloc excision was done adhering to oncological principles. This required resection of superficial femoral artery alone in two cases, resection of superficial femoral artery along with common femoral vein and femoral nerve in another, and of common femoral vein alone in yet another. Reconstruction was done in all these cases with reversed long saphenous vein graft. Histopathology of resected margins was free of tumor in all the four patients. One patient developed local recurrence and one developed distant metastsis. Two were disease free for one year with good functional limb, one has been disease-free for three years and another was disease-free at two years, after which he defaulted further follow-up. One patient developed arterial blowout which required ligation of common femoral artery which resulted in gangrene of the limb. He underwent amputation.

Conclusion:

Major neurovascular involvement in extremity sarcoma is not considered a contraindication for limb salvage surgery. Review of literature also supports our view. Post-operative wound related complications are more in this group of patients. However, long term functional outcome is good. Literature suggests a good long term local control after vascular resection and reconstruction.     

Cardiovascular toxicity profiles of vascular-disrupting agents

Background.

Vascular-disrupting agents (VDAs) represent a new class of chemotherapeutic agent that targets the existing vasculature in solid tumors. Preclinical and early-phase trials have demonstrated the promising therapeutic benefits of VDAs but have also uncovered a distinctive toxicity profile highlighted by cardiovascular events.

Methods.

We reviewed all preclinical and prospective phase I–III clinical trials published up to August 2010 in MEDLINE and the American Association of Cancer Research and American Society of Clinical Oncology meeting abstracts of small-molecule VDAs, including combretastatin A4 phosphate (CA4P), combretastatin A1 phosphate (CA1P), MPC-6827, ZD6126, AVE8062, and ASA404.

Results.

Phase I and II studies of CA1P, ASA404, MPC-6827, and CA4P all reported cardiovascular toxicities, with the most common cardiac events being National Cancer Institute Common Toxicity Criteria (version 3) grade 1–3 hypertension, tachyarrhythmias and bradyarrhythmias, atrial fibrillation, and myocardial infarction. Cardiac events were dose-limiting toxicities in phase I trials with VDA monotherapy and combination therapy.

Conclusions.

Early-phase trials of VDAs have revealed a cardiovascular toxicity profile similar to that of their vascular-targeting counterparts, the angiogenesis inhibitors. As these agents are added to the mainstream chemotherapeutic arsenal, careful identification of baseline cardiovascular risk factors would seem to be a prudent strategy. Close collaboration with cardiology colleagues for early indicators of serious cardiac adverse events will likely minimize toxicity while optimizing the therapeutic potential of VDAs and ultimately enhancing patient outcomes.