Introduction: Intrathecal opioids when added to local anaesthetics decrease their dosage and provide haemodynamic stability. Nalbuphine is an agonist-antagonist and acts on kappa receptors providing analgesia. Aim:The study aims to compare the analgesic efficacy of fentanyl with that of two doses of nalbuphine when used with injection bupivacaine heavy in spinal anaesthesia.

No abstract

Introduction: Caudal block is now-a -days a commonly used procedure for pain management and regional anaesthesia. The optimum volume of drugs required to reach the appropriate level is needed.

A B S T R A C TBackground: Laryngoscopy and intubation are associated with a sympathetically mediated circulatory response due to irritation of respiratory tract which is associated with increase in pulse rate and blood pressure that may be dangerous. Aims and Objectives: The aim of the present study was to determine and compare the efficacy of dexmedetomidine and fentanyl in attenuating the hemodynamic response to laryngoscopy and intubation and to detect any complication or side effect as a result of these drugs. Materials and Methods: Following approval by ethical committee, 60 ASA grade I and II patients of either sex undergoing general anaesthesia for elective surgery were included in this study. Patients were randomly divided into two groups of 30 patients each. Dexmedetomidine in a dose of 1µg/kg was given to Group A patients and Fentanyl 2 µg/kg was given to Group B patients. Both the drugs were diluted with normal saline solution to make 10ml and were administered slow intravenous 10 min before induction.The hemodynamic parameters were recorded, demographic data was analyzed using unpaired t-test and hemodynamic variables were analyzed by using unpaired and paired t-test. Side effects were analyzed using chi square test. Result: The two groups were comparable in their demographic profiles. Dexmedetomidine proved itself to be an excellent drug when given intravenously as a premedicant in dose of 1µg/kg to attenuate hemodynamic response to laryngoscopy and intubation. It blunted the hemodynamic response to laryngoscopy and intubation to a greater magnitude than fentanylin a dose of 2µg/kg intravenously as a premedicant. Conclusion: We conclude that fentanyl 2µg/kg i.v. given ten minutes prior to airway instrumentation shows an inconsistent response to laryngoscopy and intubation. Between the two drugs under study, the use of dexmedetomidine 1µg/kg i.v. is satisfactory and produces a more favorable hemodynamic profile while fentanyl 2µg/kg is found to be non-dependable and less effective for the attenuation of the pressor response to laryngoscopy and endotracheal intubation. However, further larger studies are required to strengthen these conclusions.

A recent article published in Nature Metabolism, "A network of trans-cortical capillaries as a mainstay for blood circulation in long bones," explained the long bone vascularity. In the mouse model, the authors demonstrated hundreds of transcortical vessels (TCVs) commencing from the bone marrow and traversing the whole cortical thickness. They realized that TCVs were the same as bleeding vessels of periosteal bed observed in the human tibia and femoral epiphysis during surgery. TCVs expressed arterial or venous markers and were proposed to be the backbone of bone vascularity as 80% of arterial and 59% of venous blood distributed through them. This new evidence challenged the existence of the "cortical capillaries" stated in previous literature. We conducted a review of the existing literature to compare this model with those in earlier research. The bone vascularity model was explained by many researchers who did their work in animal models like pig, dog, rabbit, and mouse. The TCVs were identified in these animal model studies as cortical capillaries or vessels of cortical canals. Studies are scarce, showing the presence of TCVs in humans. The role of TCVs in human cortical vascularity remains ambiguous until the substantial evidence is collected in future studies.