Dexmedetomidine prolongs the duration of action of mepivacaine on anesthesia of the palmar digital nerves of horses

OBJECTIVE To determine whether palmar digital nerve (PDN) blockade in horses with a combination of dexmedetomidine and mepivacaine would block the response to mechanical force applied to the digit longer than would anesthetizing these nerves with mepivacaine alone or dexmedetomidine alone. ANIMALS 8 mares with no signs of lameness. PROCEDURES In a randomized, crossover, blinded, experimental study, both PDNs of the same forelimb of each horse were anesthetized by perineural injection with either 30 mg mepivacaine alone, 250 µg of dexmedetomidine alone, or 30 mg mepivacaine combined with 250 µg of dexmedetomidine. Each horse received each treatment, and treatments were administered ≥ 2 weeks apart. The mechanical nociceptive threshold was measured at a region between the heel bulbs with the use of a digital force gauge before (baseline) and at 15-minute intervals after treatment. RESULTS The mean duration of sensory blockade of the digit was 2-fold longer when a combination of mepivacaine and dexmedetomidine was administered (371 minutes), compared with when mepivacaine alone was administered (186 minutes). Treatment with dexmedetomidine alone did not change the mechanical nociceptive threshold substantially from baseline and resulted in no clinical signs of sedation. CLINICAL RELEVANCE Results indicated that relief from digital pain provided by perineural treatment with mepivacaine for PDN blockade can be extended by adding dexmedetomidine to the injectate.

Bupivacaine-lidocaine versus Ropivacaine-lidocaine Retrobulbar Anesthesia in Vitreoretinal Surgery

Purpose: To compare efficacies of bupivacaine-lidocaine and ropivacaine-lidocaine mixtures in terms of inducing retrobulbar anesthesia during vitrectomy.Methods: Sixty patients who underwent retrobulbar anesthesia during vitrectomy were divided into two groups. Patients in group 1 received a mixture of bupivacaine and lidocaine (n = 30); patients in group 2 received a mixture of ropivacaine and lidocaine (n = 30). The effects of the two combinations were retrospectively compared and analyzed. The onset times of analgesia and akinesia were measured. Two hours after surgery, sensory blockade was assessed by touching the corneas with cotton swabs and by communicating with patients. Ocular movement was evaluated in four gaze direction quadrants. A 10-point visual analog pain scale was used to assess pain during and 2 hours after surgery. Intra- and postoperative complications were recorded.Results: The mean analgesia onset times in groups 1 and 2 were 94.62 ± 28.87 and 92.32 ± 35.53 seconds, respectively (p = 0.071); the mean akinesia onset times were 147.89 ± 59.35 and 132.57 ± 76.38 seconds (p = 0.223), respectively. Patients in group 2 reported significantly less postoperative pain and exhibited less postoperative ocular movement, compared with patients in group 1 (both p = 0.002). One patient in group 1 experienced respiratory depression after retrobulbar blockade.Conclusions: When retrobulbar anesthesia is required during vitrectomy, a ropivacaine-lidocaine mixture and a bupivacaine-lidocaine mixture induce anesthesia with similar rapidity. However, the ropivacaine-lidocaine mixture is safer and affords better-quality intra- and postoperative anesthesia.

“A COMPARATIVE STUDY OF ULTRASOUND GUIDED TECHNIQUE VERSUS PERIPHERAL NERVE STIMULATOR GUIDED TECHNIQUE IN INFRA-CLAVICULAR BRACHIAL PLEXUS BLOCK FOR UPPER LIMB SURGERIES.”

Background: Extensive use of ultrasonography for block execution has increased the success of procedure due to direct visualization of anatomical structures. Infra-clavicular brachial plexus block can be an attractive alternative to supraclavicular nerve block for upper limb surgeries. The objective of our study was to assess and compare the efcacy and success rate of USG guided technique versus PNS technique in Infra-clavicular brachial plexus block. Material And Methods: 70 adult patients with age in the range of 18-60 years, weight 50-80 Kg, ASA Grade I & II posted for elective upper limb surgeries of hand, wrist, forearm and distal arm under infra-clavicular brachial plexus block. Group P (PNS)– Nerve stimulator guided Infraclavicular brachial plexus block. Group U (USG)– Ultrasound guided Infraclavicular brachial plexus block. Block execution time, sensory blockade, motor blockade and success rate were assessed. Assessment of sensory blockade was done by Hollmen scale whereas motor block assessment was done by Bromage Scale. Results: There was statistically signicant difference between the groups for block execution time, onset of sensory and motor blockade, time for complete sensory and motor block and success rate(p<0.05). Conclusion: We conclude that, Ultrasound guided infraclavicular nerve block has shorter block execution time, faster sensory and motor block onset, signicantly earlier complete sensory and motor blockade, higher success rate with lesser pricks and minimal complications and should be preferred over PNS technique.

Comparision of dexmedetomidine and clonidine with hyperbaric bupivacain in spinal anaesthesia

Background: Alpha-2 adrenergic agonists used as adjuvant to spinal anaesthesia produce substantial sensory and motor blockade of bupivacaine. This study was planned to compare the sensory and motor blockade characteristics of intrathecal combinations of adjuvants dexmedetomidine and clonidine with hyperbaric bupivacaine in the cases who underwent lower limb surgery under spinal anaesthesia.Methods: This was prospective, randomized, double blind study. 90 patients of age group between 18-60 years, ASA grade I and II were allotted into 3 equal groups. Group B received 15 mg bupivacaine plain, group BD and BC received dexmedetomidine (5mcg) and clonidine (50mcg) as adjuvants to bupivacaine respectively.Results: The duration of 2 dermatome regression time, sensory blockade and motor blockade were longest in dexmedetomidine group (129.37±4.87; 386±58.43; 353±48.87) in compared to clonidine (109.77±5.95; 296.53±57.19; 269.7±51.2) and bupivacaine group (81.03±6.83; 211.1± 30.47;181.03±20.8). Both drugs do not affect the peak level of sensory blockade, sensory block onset and motor block onset time. Dexmedetomidine and clonidine do not cause sedation in intraoperative and postoperative period.Conclusions: We conclude that addition of dexmedetomidine and clonidine in spinal anesthesia with hyperbaric bupivacaine increase the duration of ‘2 dermatome regression’ time, sensory and motor blockade and both are more with dexmedetomidine than with clonidine.

COMPARISON OF ROPIVACAINE AND BUPIVACAINE IN ULTRASOUND-GUIDED TRANSVERSUS ABDOMINIS PLANE BLOCK FOR POSTOPERATIVE ANALGESIA IN PATIENTS UNDERGOING LAPAROSCOPIC SURGERY

Transversus Abdominis Plane (TAP) Block is a regional analgesic technique. It provides analgesia after abdominal surgery.The anterior abdominal wall is innervated by nerve afferents that course through the transverses abdominis neurovascular fascial plane. TAP block allows sensory blockade of abdominal wall skin and muscles when local anesthetic deposited above transversus abdominis muscle (TAM).

Study of duration and efficacy of chloroprocaine for spinal anesthesia in infraumbilical surgeries

Background: Spinal anesthesia is a reliable and safe technique for infraumbilical surgeries. Nevertheless, some of its characteristics may limit its use for day care surgery. Use of long-acting anesthetic drugs like bupivacaine in spinal anesthesia may lead to side effects such as delayed ambulation and risk of urinary retention. Chloroprocaine is an amino-ester local anesthetic with a very short half-life now being extensively evaluated in volunteer studies and clinical practice with a favorable safety profile and efficacy, suggesting that it may be a suitable alternative to long-acting local anesthetics like bupivacaine in day care surgeries. Aims and Objective: This study aims at evaluating the duration and efficacy of chloroprocaine in spinal anesthesia for infraumbilical surgeries. The primary outcome of the study was to evaluate the duration and efficacy of chloroprocaine 1% in spinal anesthesia for infraumbilical surgeries and the secondary outcome was to find out the incidence of adverse effects if any. Materials and Methods: In this randomized single-blinded clinical evaluation, after institutional ethical committee approval, 30 adult patients (18–70 years, ASA physical Status I-III, BMI < 36 kg/m2) scheduled for infraumbilical surgeries received chloroprocaine 40 mg intrathecally. Patients were evaluated for onset and regression of sensory and motor blockade, peak level of sensory blockade, and time of ambulation postoperatively. Results: The average duration of the surgeries was 46.87±15.24 min. Anesthesia was sufficient for the planned surgery. Only three patients required sedation intraoperatively. The median peak sensory block height was T8. The mean time for peak height sensory block was 6.6±1.673 min and complete motor block was 2±1.05 min. Mean time for complete sensory block regression was 95.37±20.79 min and complete motor block regression was 81.43±20.33 min. Four patients required inj. atropine following bradycardia and three patients required vasopressors following hypotension. Conclusion: Spinal anesthesia with chloroprocaine provides reliable sensory and motor block for short duration infraumbilical surgeries with fewer intraoperative and post-operative complications.

COMPARATIVE STUDY OF INTRATHECAL FENTANYL WITH HYPERBARIC BUPIVACAINE TO IMPROVE PERIOPERATIVE ANALGESIA IN PATIENT UNDERGOING ORTHOPEDIC SURGERY

Background: Various methods exist for treating post-operative pain which includes systemic narcotics, NSAIDS, patient-controlled analgesia, regional anaesthesia techniques, epidural local anaesthetic – narcotic mixtures, cryoanalgesia, transcutaneous electric nerve stimulation, psychological methods. Various opioides intrathecally and epidurally have been tried for post-operative analgesia. These include - morphine, pethidine, pentazocine, methadone, tramadol, Fentanyl, sufentanyl. In present study, we tried to find out analgesic effectiveness of intrathecal Fentanyl for post-operative analgesia, combined with 0.5 % Bupivacaine and side effects if any, in patients undergoing lower limb surgeries. Materials and Methods: After approval from the local ethics committee and with written informed consent from patient, a randomized controlled prospective study is carried out in the medical college and hospital.100 patients belonging to American Society of Anesthesiologists (ASA)classification I &amp; II, aged between 18-60 years, posted for elective lower limb surgeries, were randomly allocated for the study. Group-I: 50 patients received intrathecal 3 ml of 0.5 % hyperbaric Bupivacaine only. Group-II : 50 patients received intrathecal 3 ml of 0.5% hyperbaric Bupivacaine and Fentanyl 25 mcg.The patients studied across the group did not vary much with respect to age,height, weight and sex distribution. Results: The onset of sensory blockade was faster by 1.27 min in Group-BF. The perioperative and postoperative hemodynamic parameters were comparable in both the groups. The sensory analgesia in Group II was significantly prolonged by 159 mins, thus increasing the duration of analgesia. The time of first request of analgesics by the patients in group-II is prolonged compared to group-I thus prolonging the duration of analgesia. Analgesic requirement is also reduced in study group in early post-operative period. The onset of motor block was faster when Fentanyl was added to intrathecal Bupivacaine and it was 1.1 min earlier in study group. The duration of motor block to Bromage III was prolonged by almost 22 min in study group as compare to control group. Visual analogue scores were significantly lower in group-II compared to group-I after two hours of surgery thus reducing the frequency of supplemental postoperative analgesics. Conclusion: With the present study we can summarize that intrathecal Fentanyl potentiates the action of Bupivacaine thereby bringing about better quality and longer duration of analgesia, intense motor block, no hemodynamic disturbance and better postoperative outcome with/ minimum side effects.

Perioperative effect of dexmedetomidine on quality of analgesia and hemodynamic parameters in vaginal hysterectomy: A tertiary centre experience

Vaginal hysterectomy Surgery with long acting local anaesthetic like bupivacaine still requires higher doses of analgesics in the post-operative period. Dexmedetomidine is highly selective αadrenoreceptor agonist and sympatholytic drug is a useful adjunct drug in patients undergoing vaginal hysterectomy under continuous spinal epidural block (CSE). We sought to study duration of perioperative analgesia, observe the intra-operative and post-operative hemodynamic changes and post-operative sedation effect of dexmedetomidine.: The study groups were divided as Group D (study group) administered 1 µg/kg Dexmedetomidine and Group C (control group) administered 0.9% saline drip at the rate of 1ml/kg. Dexmedetomidine group had prolonged duration of sensory blockade, duration for 2 dermatomal regression of sensory blockade and the duration for motor block regression to Modified Bromage scale 0. This group had prolonged duration of Time to first request for rescue analgesic.14% patients required mephentermine for management of hypotension.Intraoperative diastolic blood pressure (DBP) was lower in study group while Intraoperative Systolic blood pressure (SBP) was comparable in both the groups. Intravenous dexmedetomidine significantly decreases the heart rate and is associated with higher incidence of bradycardia. It is effective in providing postoperative analgesia and in preventing postoperative shivering with reduced incidence of postoperative nausea and vomiting.

KINETIC STUDY COMPARISON OF IMMOBILIZED GLUCOSE ISOMERASE (GENSWEET AND SWEETZYME IT) IN STIRRED TANK REACTOR AND PACKED BED REACTOR

Various additives have been employed to extend the brachial plexus block. Dexamethasone, when added to local anesthetic block prolongation with analgesic and anti-inflammatory effects has been seen. Group I (Control group) received Inj. Lignocaine 1.5% plus adrenaline (1:200000) max safe dose of 7mg/kg+ NS- 2ml while group II (Dexa group) received Inj. Lignocaine 1.5% plus adrenaline (1:200000) max safe dose of 7mg/kg + Inj. Dexamethasone - 2ml (8mg). Total volume in each group ranged between 25-32ml considering the patients individual body weight. Block characteristics, duration and quality of analgesia in the post-operative period were noted. Dexamethasone hastens the onset and prolonged the duration of motor and sensory blockade. The mean duration of postoperative analgesia was prolonged till 8th hour in the dexamethasone group while in the control group it was continued till 3hrs, the role of rescue analgesia commenced after 3rd hour. Dexamethasone provides better hemodynamic stability and profound analgesia without any untoward side effects in the perioperative period. In the supraclavicular method of brachial plexus block, the addition of dexamethasone to lignocaine adrenaline offers excellent anesthetic and analgesia.

Comparative study of ropivacaine with tramadol and ropivacaine with midazolam for post-operative epidural analgesia

Epidural analgesia is the most commonly used method for surgical anesthesia, obstetric analgesia, post-operative pain control, and chronic pain management. These epidurals are used either as a single-shot technique or with the catheter that allows intermittent boluses or continuous infusion, or both. All of these variables are controlled by choice of drug concentration, dosage, and level of injections. To compare the onset and duration of sensory block, motor block, and post-operative analgesia duration using Ropivacaine with Tramadol and Ropivacaine with Midazolam in the Epidural technique. In this prospective, non-randomized, comparative study, the total of 160 patients who underwent surgeries below the umbilicus did under epidural technique at Govt. Kilpauk Medical college hospital a Govt. Royapettah hospital, Chennai, was screened. Patients were divided into two groups. Patients in Group R received an epidural injection of 0.5% Ropivacaine (30ml) with Tramadol 2 mg/kg, whereas patients in Group L received an epidural injection of 0.5% ropivacaine (30ml) with Midazolam (50mg/kg). On studying the comparison of the onset of sensory, motor blockade, and duration of the sensory-motor blockade in the two groups, the onset of sensory blockade, motor blockade, and duration of motor blockade was more among ropivacaine with midazolam group. In comparison, the duration of sensory blockade was more among ropivacaine with tramadol group. A statistically significant difference in onset of sensory, motor blockade, and duration of sensory blockade across the group was found (p&#60;0.005). Tramadol or Midazolam's addition to caudal epidural block with ropivacaine showed significant prolongation of post-operative analgesia compared to ropivacaine alone. The mean duration of analgesia was more among ropivacaine with the Tramadol group.