Novel device for automating exchange transfusions through umbilical venous route in neonates.

Manually performed double-volume exchange transfusion (DVET) is tedious, error-prone, and may incur the risk of embolism. We aimed to develop a device that automates the DVET procedure performed through the umbilical venous route. We evaluated changes in blood passing through the device during DVET. We developed an electro-mechanical device with accessories (tubing and valve assembly) to perform a complete DVET. It comprises two syringes driven by a common pump that moves back and forth to withdraw aliquots of the patient's blood and infuse equal volumes of donor blood. In tandem, it draws donor blood from a blood bank bag and pushes the patient blood drawn from the previous cycle into a waste bag, respectively. One-way duckbill valves and a two-way pinch valve ensure the separation of the donor and patient blood. A sensor detects bubbles and clots. A dashboard displays set and measured parameters. We tested the accuracy of the delivered flow rate and volume, electrical safety, embolus detection, and changes in hematological and biochemical values. The delivered flow and volume were within 5% of the set parameters. All electrical safety parameters were within normal limits. The sensor consistently detected microbubbles and clots. There were no clinically significant differences in laboratory parameters between samples drawn directly from the blood bank bag and drawn from the exit port at 80, 100, 120, and 160 s with a fixed aliquot volume. CONCLUSIONS: Our prototype of a novel device can safely automate a DVET. Further trials of this device are warranted. WHAT IS KNOWN: • Double volume exchange transfusion is often performed manually, but this is time-consuming and error-prone. • Previous attempts at automation were not widely adopted because they involved inserting two catheters and did not have mechanisms to prevent embolism. WHAT IS NEW: • This novel device fully automates double volume exchange transfusions through a single-lumen umbilical venous catheter. • It prevents air and clot embolism and has a screen for input and output parameters and alarms.

Aetiological Spectrum of Urticaria.

One hundred patients of urticaria were investigated to establish the causative agents. ,A detailed hist,6ry,:ccal examination and routine investigations led to detection of the cause m O/. patie s. Bacterial foci were responsible in 10%, worm infestations in 6%, drugs in 6%, insect bites in 3%, cold in 2%, chofine 'c in 4% and demographic in 3% rgl cases. In 60% cases, the cause was detected by intradermal tests with antigen extracts of pouen- hm fragments, dust, danders and food. Inhalantt were responsible in 35%: and foods in 25% cases. Among inhalants, pollen were found in 26%, insects in 1%, fungi in 9%, house dust and buffalo dander 'm 10/c each. In 6%, patients, no cause could be detected it; of extensive investigation.