Effects of Low Dose Vasopressin in Catecholamine Resistant Septic Shock

Background

Septic shock commonly leads to death in critically ill patients. Severe hypotension resistant to conventional catecholamine leads to multiorgan failure. We studied the effectiveness of low dose vasopressin in resistant septic shock.

Methods

Thirty critically ill patients with catecholamine resistant hypotension were included in the study. After adequate fluid resuscitation, infusion of norepinephrine and dobutamine was started. If the patient remained hypotensive, vasopressin was infused at a fixed rate of 0.04 unit/minute for 24 hours. Haemodynamic parameters and mortality rates were recorded.

Result

There was a significant improvement in systolic and mean arterial pressure within four hours of starting vasopressin. This improvement continued throughout the 24-hour period. In addition, it was possible to withdraw dopamine in all the patients and significantly reduce infusion rates of dobutamine and norepinephrine. No significant complication was noted.

Conclusion

Low dose vasopressin at the rate of 0.04 unit/minute is an effective vasopressor in adult patients with catecholamine resistant septic shock.Key Words: Severe sepsis, Septic shock, Vasopressin     

Awake Craniotomy for Tumour Excision

Background

Craniotomy and excision of tumours can produce neurological deficits if the tumour is located close to eloquent areas of the brain. One technique of overcoming this problem is to keep the patient ‘awake’ during surgery.

Methods

Eight patients with intra cranial space occupying lesions (ICSOL) were operated ‘awake’, using a combination of skull block with sedation and analgesia. A mixture of 0.125% bupivacaine and 0.5% lignocaine was used for various nerve and field blocks. Midazolam, fentanyl and propofol in titrated doses were used to achieve conscious sedation.

Result

The procedure was successful in all the patients. They tolerated the procedure well and were able to follow the commands intraoperatively as desired. There were no significant complications.

Conclusion

Awake craniotomy with skull blocks with sedation and analgesia is a well established procedure. It requires a good rapport between surgeon, anaesthesiologist and the patient.Key Words: Awake craniotomy, Skull block, Sedation, Analgesia     

Nanotechnology for nanomedicine and delivery of drugs

Nanotechnology is an emerging technology seeking to exploit distinct technological advances controlling the structure of materials at a reduced dimensional scale approaching individual molecules and their aggregates or supramolecular structures. The manipulation and utilization of materials at nanoscale are expected to be critical drivers of economic growth and development in this century. In recent years, nanoscale sciences and engineering have provided new avenues for engineering materials down to molecular scale precision. The resultant materials have been demonstrated to have enhanced properties and applicability; and these materials are expected to be enabling technologies in the successful development and application of nanomedicine. Nanomedicine is defined as the monitoring, repair, construction, and control of human biological systems at the molecular level using engineered nanodevices and nanostructures. Electrospinning is a simple and cost-effective technique, capable of producing continuous fibers of various materials from polymers to ceramics. The electrospinning technique is used for the preparation of nanofibers and macroporous scaffolds intended for drug delivery and tissue engineering. These have special characteristics in terms of fabrication, porosity, variable diameters, topology and mechanical properties. This review summarizes the recent developments in utilizing nanofibers for drug delivery and tissue engineering applications.     

Radiosynthesis of [18F]ATPFU: a potential PET ligand for mTOR

Mammalian target of rapamycin (mTOR) plays a pivotal role in many aspects of cellular proliferation, and recent evidence suggests that an altered mTOR signaling pathway plays a central role in the pathogenesis of aging, tumor progression, neuropsychiatric, and major depressive disorder. Availability of a mTOR‐specific PET tracer will facilitate monitoring early response to treatment with mTOR inhibitors that are under clinical development. Towards this we have developed the radiosynthesis of [¹⁸F]1‐(4‐(4‐(8‐oxa‐3‐azabicyclo[3.2.1]octan‐3‐yl)‐1‐(2,2,2‐trifluoroethyl)‐1H‐pyrazolo[3,4‐d]pyrimidin‐6‐yl)phenyl)‐3‐(2‐fluoroethyl)urea [¹⁸F]ATPFU ([¹⁸F]1) as an mTOR PET ligand. Synthesis of reference 1 and the precursor for radiolabeling, 4‐(4‐8‐oxa‐3‐azabicyclo[3.2.1]‐octan‐3yl)‐1‐(2,2,2‐trifluoroethyl)‐1H‐pyrazolo[3,4‐d]pyrimidin‐6yl)aniline (10), were achieved from beta‐chloroaldehyde 3 in 4 and 5 steps, respectively, with an overall yield of 25–28%. [¹⁸F]Fluoroethylamine was prepared by heating N‐[2‐(toluene‐4‐sulfonyloxy)ethyl]phthalimide with [¹⁸F]fluoride ion in acetonitrile. [¹⁸F]1 was obtained by slow distillation under argon of [¹⁸F]FCH₂CH₂NH₂ into amine 10 that was pre‐treated with triphosgene at 0–5 °C. The total time required for the two‐step radiosynthesis including semi‐preparative HPLC purification was 90 min, and the overall radiochemical yield of [¹⁸F]1 for the process was 15 ± 5% based on [¹⁸F]fluoride ion (decay corrected). At the end of synthesis (EOS), the specific activity was 37–74 GBq/µmol (N = 6).