Reduction In Dose Requirement Research Articles

English

BACKGROUND Inguinal hernia is a frequently encountered surgical problem. General anaesthesia carries the risk of possible airway complications. Regional blocks improve acute post-operative pain, decrease post-operative visual analogue scale (VAS) score and patient can mobilise early. The purpose of this study was to compare the effectiveness of transversus abdominis plane (TAP) block vs. paravertebral (PVB) block for post-operative analgeia in inguinal hernia surgeries. METHODS We conducted a research on 64 patients of age > 18 years with American society of Anaesthesiologists (ASA I – III) to undergo unilateral inguinal herniorrhaphy. Patients were randomized into two groups. Group T received TAP block in which 20 ml of 0.25 % bupivacaine was injected and Group P underwent PVB in which 5 ml of bupivacaine (0.25 %) at each segment from T10-L1 was injected slowly (total dose of 20 ml). Post-operative VAS score, time for first rescue analgesia, total diclofenac requirement, total anti-emetic requirement and complications if any was noted. RESULTS The demographic data of both the groups were comparable. Also, pre and postoperative heart rate, blood pressure, IV fluids, ephedrine use, operative time and complications were statistically insignificant. As compared to group T, group P had lower VAS score from 2nd – 12th hour which was statistically significant (P < 0.05). Although more time is required to perform paravertebral block but the time for request of first rescue analgesia was quite prolonged in paravertebral block. Time of ambulation in group P was significantly lower than group T. CONCLUSIONS PVB requires more time to perform due to multiple site of injection, the comparison of both techniques in the present study revealed that PVB showed relatively higher efficacy in the management of post-operative pain, early ambulation and had significant reduction in dose requirement of additional analgesia (diclofenac) and antiemetics (ondansetron) over tap block. KEYWORDS Paravertebral Block, Transversus Abdominis Block, Inguinal Hernia

Bioavailability of curcumin and curcumin glucuronide in the central nervous system of mice after oral delivery of nano-curcumin

Curcumin is a bioactive molecule extracted from Turmeric roots that has been recognized to possess a wide variety of important biological activities. Despite its great pharmacological activities, curcumin is highly hydrophobic, which results in poor bioavailability. We have formulated this hydrophobic compound into stable polymeric nanoparticles (nano-curcumin) to enhance its oral absorption. Pharmacokinetic analysis after oral delivery of nano-curcumin in mice demonstrated approximately 20-fold reduction in dose requirement when compared to unformulated curcumin to achieve comparable plasma and central nervous system (CNS) tissue concentrations. This investigation corroborated our previous study of curcumin functionality of attenuating opioid tolerance and dependence, which shows equivalent efficacy of low-dose (20mg/kg) nano-curcumin and high-dose (400mg/kg) pure curcumin in mice. Furthermore, the highly selective and validated liquid chromatography⿿mass spectrometry (LC⿿MS) method was developed to quantify curcumin glucuronide, the major metabolite of curcumin. The results suggest that the presence of curcumin in the CNS is essential for prevention and reversal of opioid tolerance and dependence.

Regional Anaesthesia for Bilateral Upper Limb Surgery: A Review of Challenges and Solutions

Regional anaesthesia for bilateral upper limb surgery can be challenging, yet surgeons are becoming increasingly interested in performing bilateral procedures at the same operation. Anaesthetists have traditionally avoided bilateral brachial plexus block due to concerns about local anaesthetic toxicity, phrenic nerve block and pneumothorax. We discuss these three concerns and review whether advances in ultrasound guidance and nerve catheter techniques should make us reconsider our options. A search of Medline and EMBASE from 1966 to January 2009 was conducted using multiple search terms to identify techniques of providing anaesthesia or analgesia for bilateral upper limb surgery and potential side-effects. Ultrasound imaging and nerve catheter techniques have led to a reduction in dose requirements for effective blocks without side-effects. Effective regional anaesthesia can be performed for bilateral surgery while remaining within recommended safe dose limits. Spacing blocks apart in time can further reduce potential toxicity issues, such that peak absorption rates for each block do not coincide. Since phrenic nerve block remains an issue even with low doses of local anaesthesia, bilateral interscalene blocks are still not recommended. Peripheral nerve blocks have excellent safety profiles and are ideal for ultrasound guidance. Regional anaesthesia can be a suitable option for bilateral upper limb surgery.

A comparison of mivacurium dosage requirements during isoflurane and desflurane anesthesia

Study Objective: To evaluate the dose requirement and recovery characteristics of mivacurium infusions during anesthesia with equipotent concentrations of either desflurane or isofiurane. Design: Randomized, open-study comparing the effects of desflurane and isoflurane on mivacurium-induced neuromuscular blockade. Setting: Operating suite of a university-affiliated medical center. Patients: 41 ASA status I, II, and III adult patients, requiring more than 45 minutes of neuromuscular blockade for surgery. Interventions: Following a standardized induction sequence and established steady desflurane-nitrous oxide (DES group) or isoflurane-nitrous oxide (ISO group) anesthesia at 1 minimum alveolar concentration (MAC), an intubating dose of 0.2 mg/kg of mivacurium chloride was administered. Ventilation was maintained with a face mask until the first twitch (T1) of the evoked train-of-four (TOF) reached 10% or less of control when tracheal intubation was performed. T1 was allowed to return to 10% of its control value. An infusion of mivacurium at the initial rate of 5 μg/kg/min was then started and adjusted to maintain T1 at 10% ± 2% of control. Within 20 minutes of completion of surgery, the mivacurium infusion was stopped, and the time for the evoked electromyograph (EMG) to return to 25% and 75% of the original baseline was noted. Measurements and Main Results: Neuromuscular function was monitored continuously by an evoked EMG. The average infusion rate was 5.7 ± 2.4 μg/kg/min (mean ± SD) for DES group (n = 20) and 6.6 ± 2.7 μg/kg/min for ISO group (n = 21) (p = NS). There was no change in the infusion rate of mivacurium over time for both groups. However, there was an inverse relationship in both groups between the time to recovery following a bolus dose and the subsequent mean infusion rate of mivacurium (correlation coefficient = −5.0; p < 0.005). The spontaneous recovery index (T25–75)for the two groups was identical, 11.5 ± 4.9 min (mean ± SD) for DES group and 11.5 ± 7.9 min for ISO group (p = NS). Conclusion: There were no differences in the dose requirement and recovery indices of mivacurium during either desflurane or isoflurane-based anesthesia. Patients who took longer to recover from the bolus dose in both groups showed a subsequent reduction in dose requirements of mivacurium.