RESUMEN
Immobilization material has slowly revolutionized since 3000 BCE from traditional plaster to modern day synthetic casting tape, including other sustainable immobilization material. This revolution is driven by the search for superior casting material that possesses excellent mechanical and load-bearing properties, non-toxicity, excellent healing rates, patient satisfaction and eco friendliness. Even though the new materials have been evolved, the traditional plaster still remains a material of choice owing to its excellent skin conformability, low cost and availability. This paper aims to present a comprehensive review on the technique of immobilization, existing orthopedic immobilization (casting and splinting) materials and complications associated with immobilization (mainly casting) which aimed to assist the medical practitioners and researchers in casting material improvements and selection. Nine immobilization materials are comprehensively discussed for their desirable properties, drawbacks and the required improvements to the composition, along with the most common cast complications ranging from superficial pressure sores to compartment syndrome and Deep Vein Thrombosis. . This paper identifies that among the existing material, plaster casts are still highly used due to their cost benefit and the ability to fit patients into full body casts, while synthetic material is too rigid and has a higher probability of causing complications such as compartment syndrome and deep vein thrombosis. Patients show a higher preference in using synthetic casts for short term and body extremity casting as they are comparatively more comfortable. New materials such as Woodcast shows good promise but their mechanical characteristics and comfort are yet to be critically analyzed. However, there exists an imminent requirement to upgrade existing material as well as to introduce novel promising sustainable material for long term immobilization.
RESUMEN
Objectives: To construct gestation specific reference limits for fetal umbilical (UA), middle cerebral artery (MCA) pulsatility indices (PI) and the cerebroplacental ratio (CPR) in singleton pregnancies with normal BMI between 16 and 40 weeks of gestation. Methods: We ultrasonographically examined 596 fetuses from women with normal nutritional and health status and minimal environmental constraints on fetal growth. Each mother was considered only once for measurement of fetal Doppler indices, at gestations between 16 and 40 weeks in a prospective cross-sectional study. Gestational age was confirmed by fetal crown-rump length measurement between 11 and 14 weeks. Pulsatility indices of umbilical and middle cerebral arteries were measured by real time and Doppler ultrasonography. CPR ratio was calculated by dividing MCA PI by UA PI. The fetal Doppler measurements obtained from the current study were compared with commonly used reference charts. For each parameter separate polynomial regression models were fitted to estimate the gestation specific means and standard deviations, assuming that the measurements have a normal distribution at each gestational age. Results: A significant difference of fetal Doppler indices was observed between our study and previously published reference charts for most gestational weeks. The fitted 10th, 50th and 90th centiles at 40 weeks of gestation were 0.65, 0.87 and 1.08 for UA PI; 0.93, 1.32 and 1.71 MCA PI; 1.02, 1.58 and 2.13 for CPR. Conclusions: These charts can be used for better defining the normal range of fetal arterial Doppler indices. This will be useful in the diagnosis and management of fetuses with abnormal fetal growth.
