Clinical profile and outcome of intermediate syndrome in acute organophosphate poisoning

Background: Deaths by acute organ phosphorus poisoning is very common in rural India especially in people associated with agriculture sector. The present study was aimed to study the clinical characteristics of organ phosphorus compound (OPC) poisoning and to assess the associated factors related to the outcome (recovery/death) of intermediate syndrome (IMS).Methods: This is an observational study conducted on 40 patients showing features of intermediate syndrome at Poison center, Institute of internal medicine, Rajiv Gandhi Government General Hospital, Chennai. Detailed clinical examination was done on the day of admission and daily with close monitoring. All patients included under study will be treated with pralidoxime as per protocol, atropine as required and other supportive measures was provided. Mechanical ventilatory support was provided for patients in respiratory failure. Patients are followed up till the end point of outcome (recovered and discharged/death) that was correlated with type of compound, quantum of exposure, duration of IMS, serum cholinesterase and creatinine kinase levels and respiratory failure.Result: Patients of age group between 30-40 years are more affected. Males outnumbered the females and most of them are from agriculture sector (65%). Out of 40, on treatment and follow up 34 patients were recovered and 6 were died. Onset of intermediate syndrome ranges between days 2-4 following exposure and duration of symptoms was observed for 5� days. Methylparathion was the frequent compound associated with IMS in about 9 cases. Out of 40, 16 had respiratory failure and given ventilator support. Proximal muscle weakness was seen in about 38 patients as common symptom.Conclusion: The results of the present study concludes that factors such as mode of poisoning, onset of IMS, type of compound, PChE level are not correlated with the outcome of study. Duration of IMS, respiratory failure, ventilator associated pneumonia (VAP), ventilator support duration were associated with outcome of the study. Hence, early recognition of IMS and its associated respiratory paralysis is very important in patients affected with OPC toxicity to prevent morbidity and mortality rate.

Design of homogeneous and heterogeneous human equivalent thorax phantom for tissue inhomogeneity dose correction using TLD and TPS measurements

The purpose of this study is to fabricate inexpensive in-house low cost homogeneous and heterogeneous human equivalent thorax phantom and assess the dose accuracy of the Treatment Planning Systems [TPS] calculated values for different lung treatment dosimetery. It is compared with Thermoluminescent Dosimeter [TLD] measurement. Homogeneous and heterogeneous thorax human equivalent phantoms were fabricated using bee's wax [density=0.99 g/cm[3]] as a tissue simulating material, with inserts of cork [density=0.2 g/cm[3]] and Teflon [density=2 g/cm[3]] as lung and spine simulating material respectively. Lithium fluoride [LiF] TLD capsules were irradiated for different thoracic tumor treatment techniques using the locally fabricated homogeneous and heterogeneous phantoms. The 3D TPS calculated values of homogeneous and heterogeneous phantoms were compared with TLD measured values. Experiments were carried out for different thoracic tumour treatment techniques for small and larger field sizes and also with and without wedge for Cobalt - 60 photon beams. Plato TPS were used to calculate the inhomogeneity for the homogeneous and heterogeneous phantoms. TLD and 3D TPS calculated values were found to have deviation of +/- 5%. Both the homogeneous and heterogeneous phantoms has proved to be a valuable tools in the development and implementation of external beam radiotherapy [EBRT] in the clinical thorax region and in the verification of absolute dose and dose distributions in the regions of clinical and dosimetric interest

Fabrication of low cost in-house slab homogeneous and heterogeneous phantoms for lung radiation treatment

The heterogeneous composition of the human body presents numerous tissue types and cavities with widely differing radiologic properties. The aim of the present work was to develop a low cost homogeneous and heterogeneous phantom and the absorbed dose were measured by ionization chamber for different radiotherapy treatment techniques and compared with treatment planning system absorbed dose values. Present work deals with the fabrication of inexpensive homogeneous and heterogeneous tissue equivalent slab phantom using polymethyl methacrylate, cork, teflon and perspex as a tissue, lung, spine and tumor simulating materials respectively. These phantoms were used for different treatment techniques and full rotation techniques in SSD and SAD techniques. The measured dose values for the different positions of both phantoms were compared with the TPS values. The values are coinciding with each other and the percentage of deviation varies from 0.47 to 2.8 and 0.49 to 2.86 for heterogeneous and homogeneous phantoms respectively. The measured values from ion chamber were compared with 3-D Plato Treatment Planning System [TPS]. TPS values were also revealed the same result for homogeneous and heterogeneous phantoms. The dose value of tumor is found to be gradually decreased with increase in arc angle. The dose value of spine is also found to be gradually decreased up to 90° and increased in 360°. Heterogeneity correction would definitely improve the cancer treatment of the heterogeneity region. This in-house phantom is inexpensive, easy to handle and very useful one to verify the TPS calculation