Crystalloid preload versus crystalloid coload for parturients undergoing cesarean section under spinal anesthesia

Context: There is a paucity of studies comparing crystalloid preload and coload in parturients undergoing cesarean section under spinal anesthesia from India. Aims: To compare crystalloid preload and coload for the prevention of maternal hypotension in parturients undergoing cesarean section under spinal anesthesia. Secondary outcomes studied included requirement of ephedrine for treatment of hypotension, maternal nausea and vomiting, neonatal APGAR scores and acid base status. Settings and Design: Tertiary level, teaching hospital. Prospective, randomized study. Materials and Methods: Hundred parturients, aged 20 to 40 years, American Society of Anesthesiologist (ASA) physical status 1 or 2, with singleton, uncomplicated pregnancies scheduled for cesarean section under spinal anesthesia were randomized into two groups. Subjects in group P received 15 ml/kg of lactated Ringer′s (RL) solution as preload over 20 min before the placement of spinal block, while those in group C received 15 ml/kg of RL over 20 min, starting as soon as CSF was tapped. Statistical Analysis Used: Student′s t-test, Chi-square test, Fisher′s test. Results: The number of parturients developing hypotension in group P and C was 30 and 23 respectively and was comparable statistically. More number of patients developed nausea (19 versus 10, P = 0.0473) and vomiting (14 versus 6, P = 0.0455) in group P as compared to group C and these values were statistically significant. The mean number of doses of ephedrine required (2.6 in group P and 1.8 in group C) and the total dose of ephedrine used (14.2 mg and 12.6 mg in groups P and C respectively) in the groups were comparable statistically. Conclusions: Both preloading and coloading with 15 ml/ kg of RL solution are ineffective in the prevention of spinal-induced maternal hypotension. We recommend frequent monitoring of maternal blood pressure (at 1-min intervals) and prompt treatment of maternal hypotension with vasopressors for better neonatal outcomes

Enhancement and Detection of Mechanical Damage MFL Signals from Gas Pipeline Inspection

Natural gas is transported in United States through a vast network of transmission pipelines that requires routine maintenance for safe and efficient transport of this cheap form of energy [1]. In order to ensure the integrity of the system, the pipelines are periodically inspected using tools called “pigs” which are propelled inside the pipe under the pressure of natural gas. Figure 1 shows the schematic of a typical pig structure. The pig, in brief, is a magnetizer-sensor assembly, employing the magnetic flux leakage (MFL) technique for assessing the condition of the pipe. A strong permanent magnet in the pig saturates the pipe wall with magnetic flux flowing in the axial direction. When the pig encounters an anomaly as it traverses the pipe, a part of the flux leaks out. This MFL signal is detected by a flux sensitive device such as an Hall-effect sensor. An array of Hall sensors is usually installed around the circumference of the pig (between the two poles of the magnetizer) for this purpose. The signal picked up by the sensor array can be interpreted as an “magnetic image” of the condition of pipeline, where the shape and amplitude of the signal is indicative of the nature of the anomaly. The MFL data is recorded and stored using an on-board data acquisition system, and subsequently analyzed by data analysts.</p

Enhancement and Detection of Mechanical Damage MFL Signals from Gas Pipeline Inspection

Natural gas is transported in United States through a vast network of transmission pipelines that requires routine maintenance for safe and efficient transport of this cheap form of energy [1]. In order to ensure the integrity of the system, the pipelines are periodically inspected using tools called “pigs” which are propelled inside the pipe under the pressure of natural gas. Figure 1 shows the schematic of a typical pig structure. The pig, in brief, is a magnetizer-sensor assembly, employing the magnetic flux leakage (MFL) technique for assessing the condition of the pipe. A strong permanent magnet in the pig saturates the pipe wall with magnetic flux flowing in the axial direction. When the pig encounters an anomaly as it traverses the pipe, a part of the flux leaks out. This MFL signal is detected by a flux sensitive device such as an Hall-effect sensor. An array of Hall sensors is usually installed around the circumference of the pig (between the two poles of the magnetizer) for this purpose. The signal picked up by the sensor array can be interpreted as an “magnetic image” of the condition of pipeline, where the shape and amplitude of the signal is indicative of the nature of the anomaly. The MFL data is recorded and stored using an on-board data acquisition system, and subsequently analyzed by data analysts