Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2005
A novel technique for experimental stellate ganglion block in rats.
A stellate ganglion block (SGB) is routinely performed in a clinical setting for the treatment of sympathetically maintained pain syndromes. However, the cardiovascular effects of SGB have not been well defined. The purpose of the present study was to develop a new technique of SGB in a rat model. Our new technique of SGB is a posterior percutaneous approach and uses the cartilaginous process of the C7 spinous process as a landmark. Twenty-six Sprague-Dawley female rats were divided into six groups. Group I (n = 4) underwent right sided SGB, Group II (n = 5) underwent left-sided SGB, and Group III (n = 5) underwent bilateral SGB using bupivacaine 0.25%. Three additional sham groups (n = 4 in each group) served as controls to each of the three treatment groups. Ipsilateral eyelid droop (ptosis) was observed in all animals that underwent SGB with bupivacaine. Heart rate decreased significantly for up to 45 min after bilateral SGB compared with control groups. However, this value did not change in rats after unilateral SGB. In 9 additional rats, we evaluated the accuracy of SGB by injecting methylene blue to stain the right (n = 3), left (n = 3), and bilateral SGB (n = 3). At autopsy, 11 of 12 SG were stained post-methylene blue injection. We conclude from our study that our new approach, posterior percutaneous SGB is a reliable technique that can be used for further studies. ⋯ We describe a new technique for stellate ganglion block in rats that may be used in future studies to investigate the role of cervical sympathetic nervous system (especially the stellate ganglion) in regulating sympathetically maintained pain and myocardial function.
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Anesthesia and analgesia · Aug 2005
Randomized Controlled Trial Comparative Study Clinical TrialIntraarticular patient-controlled regional anesthesia after arthroscopically assisted anterior cruciate ligament reconstruction: ropivacaine/morphine/ketorolac versus ropivacaine/morphine.
Anterior cruciate ligament reconstruction (ACLR) is associated with moderate to severe postoperative pain. We compared the intraarticular analgesic effects of ropivacaine and morphine with or without ketorolac and the need for rescue IV morphine at rest and during movement in patients undergoing anterior cruciate ligament reconstruction during spinal anesthesia. Thirty-nine patients receiving intraarticular patient-controlled regional analgesia with a 10-mL bolus and a 60-min lockout interval were randomized into 3 groups: the RM group received 0.25% ropivacaine and morphine 0.2 mg/mL; the RMK group received 0.25% ropivacaine, morphine 0.2 mg/mL and ketorolac 1 mg/mL; the P group received saline. Analgesic mixtures were prepared in 100-mL bags and coded. If needed, rescue morphine 2 mg was self-administered IV with 10-min lockout intervals. Pain scores and patient satisfaction were assessed at rest and during movement. There were no significant differences among the groups in pain scores and patient satisfaction. Daily morphine consumption was significantly smaller in the RMK group (8 +/- 8 mg) compared with the RM group (23 +/- 20 mg; P = 0.002) and in both groups compared with control (46 +/- 21 mg; P < 0.001). We conclude that intraarticular patient-controlled regional analgesia provides effective pain relief after anterior cruciate ligament reconstruction. The combination of intraarticular ropivacaine, morphine, and ketorolac was superior to control or to a combination of ropivacaine and morphine. ⋯ This study showed the feasibility and efficacy of intraarticular patient-controlled regional analgesia technique for pain relief after anterior cruciate ligament reconstruction. The combination of intraarticular ropivacaine, morphine, and ketorolac was superior to control or to a combination of ropivacaine and morphine.
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Anesthesia and analgesia · Aug 2005
Randomized Controlled Trial Comparative Study Clinical TrialA double-blind comparison of intravenous ondansetron and placebo for preventing postoperative emesis in 1- to 24-month-old pediatric patients after surgery under general anesthesia.
We assessed the efficacy and safety of ondansetron (0.1 mg/kg IV) prophylactically administered before surgery for prevention of postoperative vomiting (POV) in a double-blind, placebo-controlled study of 670 pediatric patients, 1- to 24-mo-old, undergoing elective surgery under general anesthesia. The study enrolled 335 children in each treatment group (ondansetron versus placebo). Significantly fewer children treated with ondansetron exhibited emesis or discontinued the study prematurely after surgery (ondansetron, 11%; placebo, 28%; odds ratio = 0.33; P < 0.0001). The number required to treat prophylactically with ondansetron to prevent POV was approximately six. Ondansetron treatment also resulted in fewer patients requiring rescue medication or assumed to have had rescue upon early discontinuation from the study during the postoperative period (ondansetron, 5%; placebo, 10%) and less emesis (0 of 6) after rescue medication when compared with placebo (7 of 21). The incidence of POV and other antiemetic effects of ondansetron were similar in children aged 1-12 mo and 13-24 mo and in children prospectively expected or not expected to require opioids as part of their anesthetic or analgesic management. Ondansetron was well tolerated; the incidence of adverse events considered possibly related to study drug was similar between treatment groups (ondansetron, 1.8%; placebo, 1.5%). ⋯ This prospective, randomized, double-blind, placebo-controlled study establishes the efficacy and tolerability of IV ondansetron (0.1 mg/kg) in the prevention of postoperative emesis in 1- to 24-mo-old pediatric patients undergoing elective surgery under general anesthesia.
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Anesthesia and analgesia · Aug 2005
Randomized Controlled Trial Comparative Study Clinical TrialThe influence of lumbosacral cerebrospinal fluid volume on extent and duration of hyperbaric bupivacaine spinal anesthesia: a comparison between seated and lateral decubitus injection positions.
We designed the present study to examine the influence of lumbosacral cerebrospinal fluid (CSF) volume on the spread and duration of hyperbaric bupivacaine spinal anesthesia when the injection is made with the patient in the lateral position compared with that when the patient is in a seated position. Seventy-four patients undergoing peripheral orthopedic or urogenital surgery with spinal block were enrolled. Lumbosacral CSF volumes were calculated from axial magnetic resonance images. Patients were randomly assigned to 1 of 2 groups: the lateral (L) and seated (S) groups (n = 37 each). Spinal anesthesia (3 mL hyperbaric 0.5% bupivacaine) was administered using a 25-gauge pencil-type needle with the needle aperture directed cephalad and the patient in the lateral decubitus position with the non-operated side up (L group) or with the patient in a seated position (S group). Patients were turned supine immediately after spinal injection (L group) or after remaining seated for 2 min (S group). Statistical correlation coefficients (rho) were assessed using Spearman's rank correlation. There were negative correlations between CSF volume and peak sensory block level in both the L (rho = -0.69, P < 0.0001) and S groups (rho = -0.68, P < 0.0001). In the S group, but not in the L group, CSF volume significantly correlated with onset time of peak sensory block level (rho = -0.48, P = 0.004), and time required for regression to L1-4 (P < 0.05-0.01). We conclude that CSF volume influences the spread of spinal anesthesia with hyperbaric bupivacaine regardless of patient position when the spinal injection is made. CSF volume influenced the duration of spinal sensory anesthesia when the injection was made with the patient in a seated position, but not in the lateral position. ⋯ Patient position during the spinal injection does not alter the influence of cerebrospinal fluid (CSF) volume on the spread of hyperbaric bupivacaine spinal anesthesia. However, CSF volume influences the duration of spinal sensory anesthesia when the injection is made with the patient in a seated position, but not in the lateral position.