Risk Factors for New-Onset Persistent Low-Back Pain Following Nonobstetric Surgery Performed With Epidural Anesthesia.
Reg Anesth Pain Med. 2012 Jan 26;
Authors: Hakim SM, Narouze S, Shaker NN, Mahran MA
Abstract
BACKGROUND: The aim of this trial was to identify risk factors for persistent low-back pain (LBP) of new onset following nonobstetric surgery performed with lumbar epidural anesthesia. METHODS: Four-hundred eighty-three patients with no history of LBP were screened for backache 2 days, 10 days, and 13 weeks after nonobstetric surgeries were performed with lumbar epidural anesthesia. Demographic data, details of epidural techniques, and operative data were compared in patients who developed back pain that persisted for 13 weeks with those patients who did not. Multivariate logistic regression analysis was performed to identify predictors of persistent LBP. RESULTS: Ten patients (2.1%) consistently experienced clinically significant LBP at 2 days, 10 days, and 13 weeks after surgery; they were labeled as having persistent LBP. Multivariate analysis showed that higher body mass index (P < 0.001), multiple attempts at epidural placement (P = 0.026), surgery in the lithotomy position (P = 0.013), and duration of surgery exceeding 2½ hrs (P = 0.025) were independent risk factors for persistent LBP. As much as 51% of variation in the outcome measure could be explained by the model (R = 0.51), which had an overall accuracy of 98.1%. CONCLUSIONS: Persistent LBP after nonobstetric surgery performed with lumbar epidural anesthesia is rather rare. Independent risk factors for this untoward outcome are higher body mass index, multiple trials at epidural placement, surgery in the lithotomy position, and operative time exceeding 2½ hrs. These results need to be validated by prospective trials using larger cohorts.
PMID: 22286517 [PubMed - as supplied by publisher]
Transversus Abdominis Plane Block: The Effects of Surgery, Dosing, Technique, and Timing on Analgesic Outcomes: A Systematic Review.
Reg Anesth Pain Med. 2012 Jan 26;
Authors: Abdallah FW, Chan VW, Brull R
Abstract
ABSTRACT: Ultrasound guidance has led a surge of interest in transversus abdominis plane (TAP) block for postoperative analgesia following abdominal surgery. Despite or because of the numerous descriptive applications and techniques that have recently populated the literature, results of comparative studies for TAP block have been inconsistent. This systematic review pragmatically addresses many unanswered questions, specifically the following: what are the effects of surgical procedure, block dose, block technique, and block timing on TAP block analgesia?Eighteen intermediate- to good-quality randomized trials that included diverse surgical procedures were identified. Improved analgesia was noted in patients undergoing laparotomy for colorectal surgery, laparoscopic cholecystectomy, and open and laparoscopic appendectomy. There was a trend toward superior analgesic outcomes when 15 mL of local anesthetic or more was used per side compared with lesser volumes. All 5 trials investigating TAP block performed in the triangle of Petit and 7 of 12 trials performed along the midaxillary line demonstrated some analgesic advantages. Eight of 9 trials using preincisional TAP block and 4 of 9 with postincisional block revealed better analgesic outcomes. Although the majority of trials reviewed suggest superior early pain control, we were unable to definitively identify the surgical procedures, dosing, techniques, and timing that provide optimal analgesia following TAP block. This review suggests that our understanding of the TAP block and its role in contemporary practice remains limited.
PMID: 22286518 [PubMed - as supplied by publisher]
Neurologic Complications After Chlorhexidine Antisepsis for Spinal Anesthesia.
Reg Anesth Pain Med. 2012 Jan 26;
Authors: Sviggum HP, Jacob AK, Arendt KW, Mauermann ML, Horlocker TT, Hebl JR
Abstract
BACKGROUND AND OBJECTIVES: Recent reports of infectious complications after neuraxial procedures highlight the importance of scrupulous aseptic technique. Although chlorhexidine gluconate (CHG) has several advantages over other antiseptic agents; including a more rapid onset of action, an extended duration of effect, and rare bacterial resistance, it is not approved by the US Food and Drug Administration for use before lumbar puncture because of absence of clinical safety evidence. The objective of this retrospective cohort study was to test the hypothesis that the incidence of neurologic complications associated with spinal anesthesia after CHG skin antisepsis is not different than the known incidence of neurologic complications associated with spinal anesthesia. METHODS: All patients 18 years or older who underwent spinal anesthesia at Mayo Clinic Rochester from 2006 to 2010 were identified. The primary outcome variable was the presence of any new or progressive neurologic deficit documented within 7 days of spinal anesthesia. The etiology of a patient’s neurologic complication was independently categorized as possibly or unlikely related to the spinal anesthetic by 3 investigators. Consensus among all reviewers was required for final category assignment. RESULTS: A total of 11,095 patients received 12,465 spinal anesthetics during the study period. Overall, 57 cases (0.46%; 95% confidence interval, 0.34%-0.58%) met criteria for neurologic complication. Spinal anesthesia was felt to be the possible etiology of 5 neurologic complications (0.04%; 95% confidence interval, 0.00%-0.08%); all completely resolved within 30 days. DISCUSSION: The incidence of neurologic complications possibly associated with spinal anesthesia (0.04%) after CHG skin antisepsis is consistent with previous reports of neurologic complications after spinal anesthesia. These results support the hypothesis that CHG can be used for skin antisepsis before spinal placement without increasing the risk of neurologic complications attributed to the spinal anesthetic.
PMID: 22286519 [PubMed - as supplied by publisher]
Electron-Microscopic Imaging of Endothoracic Fascia in the Thoracic Paravertebral Space in Rats.
Reg Anesth Pain Med. 2012 Jan 26;
Authors: Stopar Pintaric T, Veranic P, Hadzic A, Karmakar M, Cvetko E
Abstract
BACKGROUND AND OBJECTIVES: Anesthesia and analgesia with paravertebral block are reportedly variable. Existence of an endothoracic fascia has been proposed as one of the possible mechanisms leading to variability. We undertook an electron-microscopy imaging study to investigate the endothoracic fascia in the thoracic paravertebral space (TPS) in rats. METHODS: Male Wistar rats were studied in accordance with the principles of laboratory animal care. After the rats were euthanized in a CO2 chamber, the thoracic paravertebral tissues were removed en bloc and cut into consecutive transverse sections of approximately 3 mm. Stereomicroscopy and electron-microscopy assessments were performed by 2 independent observers. RESULTS: The endothoracic fascia was consistently identified in all specimens. The fascia was located between the parietal pleura and the innermost intercostal muscles or ribs. Its thickness ranged from 15 to 27 μm (mean, 20 ± 3 μm). The endothoracic fascia divided the TPS in 2 compartments: one, extrapleural and anterolateral (EPC); another, subendothoracic and posteromedial (SETC). The spinal nerves with their ganglia were found within SETC, whereas the sympathetic ganglia were consistently located within the EPC. CONCLUSIONS: The endothoracic fascia in rats appears to divide the TPS into EPC and SETC. These anatomic characteristics may have implications in thoracic paravertebral blockade.
PMID: 22286520 [PubMed - as supplied by publisher]
Bupivacaine Extended-Release Liposome Injection Exhibits a Favorable Cardiac Safety Profile.
Reg Anesth Pain Med. 2012 Jan 19;
Authors: Bergese SD, Onel E, Morren M, Morganroth J
Abstract
BACKGROUND AND OBJECTIVES: Bupivacaine extended-release liposome injection is an investigational local analgesic intended for use in postsurgical pain management. In recognition of the incompletely characterized association of bupivacaine use and cardiac effects, this article reviews the cardiac safety profile of this novel formulation of bupivacaine. METHODS: Findings from paired electrocardiograms (ECGs), corresponding pharmacokinetic assessments, and cardiovascular adverse events (AEs) in a phase 2, randomized, double-blind, dose-ranging study of bupivacaine extended-release (150, 300, 450, or 600 mg) or bupivacaine HCl 150 mg with epinephrine administered intraoperatively via wound infiltration in patients undergoing total knee arthroplasty (n = 138), were assessed for potential causality. Results from 4 phase 1 bupivacaine extended-release studies that also obtained ECG and/or Holter monitor findings (n = 169) were assessed. In addition, incidences of cardiovascular AEs reported across 10 bupivacaine extended-release wound infiltration studies (n = 1459) were pooled and assessed. RESULTS: In the phase 2 study, mean change from baseline in QRS duration and QTcF duration across dose levels of bupivacaine extended-release was similar (range, -1 to +4 milliseconds and -7 to -10 milliseconds) compared with bupivacaine HCl (-1 millisecond and -6 milliseconds). Mean change from baseline in heart rate, PR interval, and QRS interval was similar between treatment groups as well. No clinically relevant ECG changes or cardiac AEs with bupivacaine extended-release were observed in the other clinical studies. CONCLUSIONS: A focused assessment of ECG data from a phase 2 study and cardiac findings/AEs data from other studies in the bupivacaine extended-release development program did not reveal any cardiac safety issues.
PMID: 22266897 [PubMed - as supplied by publisher]
Effect of Local Anesthetic Volume (15 vs 40 mL) on the Duration of Ultrasound-Guided Single Shot Axillary Brachial Plexus Block: A Prospective Randomized, Observer-Blinded Trial.
Reg Anesth Pain Med. 2012 Jan 19;
Authors: Schoenmakers KP, Wegener JT, Stienstra R
Abstract
BACKGROUND AND OBJECTIVES: One of the advantages of ultrasound-guided peripheral nerve block is that visualization of local anesthetic spread allows for a reduction in dose. However, little is known about the effect of dose reduction on sensory and motor block duration. The purpose of the present study was to compare the duration of sensory and motor axillary brachial plexus block (ABPB) with 15 or 40 mL mepivacaine 1.5%. METHODS: Thirty patients were randomly allocated to receive ultrasound-guided ABPB with either 15 (group 15 mL, n = 15) or 40 mL (group 40 mL, n = 15) mepivacaine 1.5%. Onset, efficacy, and duration of sensory and motor block were compared. RESULTS: Two patients in group 15 mL needed an additional rescue block before surgery and were excluded from subsequent analysis. The overall median duration of sensory and motor block was significantly shorter in group 15 mL (225 [148-265] mins vs 271 [210-401] mins and 217 [144-250] mins vs 269 [210-401] mins, respectively; P < 0.01). Duration of sensory and motor block of individual nerves was significantly shorter in group 15 mL (20%-40% reduction for sensory and 18%-37% for motor block). Time to first request of postoperative analgesia was also significantly reduced in group 15 mL (163 [SD, 39] vs 235 [SD, 59] mins, respectively, P < 0.05). There were no differences in the other block characteristics. CONCLUSIONS: In ABPB with mepivacaine 1.5%, reducing the dose from 40 mL to 15 mL (62.5%) shortens the overall duration of sensory and motor block by approximately 17% to 19%, reduces sensory and motor block duration of individual nerves by 18% to 40%, and decreases the time to first request of postoperative analgesia by approximately 30%.
PMID: 22266898 [PubMed - as supplied by publisher]
The Analgesic Effects of a Bilateral Sternal Infusion of Ropivacaine After Cardiac Surgery.
Reg Anesth Pain Med. 2012 Jan 19;
Authors: Eljezi V, Dualé C, Azarnoush K, Skrzypczak Y, Sautou V, Pereira B, Tsokanis I, Schoeffler P
Abstract
BACKGROUND AND OBJECTIVES: The aim of this study was to assess the effects of a continuous postoperative administration of local anesthetic through 2 catheters placed deeply under fascia at the lateral edges of the sternum, close to the emergence of the intercostal nerves. We focused on pain during mobilization, as this aspect is likely to interact with postoperative morbidity. METHODS: Forty adult patients scheduled for open heart surgery with sternotomy were included in this randomized, placebo-controlled, double-blind study. A continuous fixed-rate infusion of 4 mL/hr of 0.2% ropivacaine or normal saline was administered during the first 48 postoperative hrs. All patients received acetaminophen and self-administered morphine. The efficacy outcomes were as follows: pain score during standardized mobilization and at rest; morphine consumption; spirometry and arterial blood gases; postoperative rehabilitation criteria, and patient satisfaction. Total ropivacaine plasma level was monitored throughout the study. RESULTS: Pain scores were lower in the ropivacaine group during mobilization (P = 0.0004) and at rest (P = 0.0006), but the analgesic effects were mostly apparent during the second day after surgery, with a 41% overall reduction in movement-evoked pain levels. The bilateral sternal block also reduced morphine consumption. It improved the patients’ satisfaction and rehabilitation, but no effects were noted on respiratory outcomes. No major adverse effect due to the treatment occurred, but the ropivacaine plasma level was greater than 4 mg/L in 1 patient. CONCLUSIONS: This technique may find a role within the framework of multimodal analgesia after sternotomy, although further confirmatory studies are needed.
PMID: 22266899 [PubMed - as supplied by publisher]
Prolongation of Epidural Analgesia Using Solid Lipid Nanoparticles as Drug Carrier for Lidocaine.
Reg Anesth Pain Med. 2012 Jan 4;
Authors: Leng F, Wan J, Liu W, Tao B, Chen X
Abstract
BACKGROUND AND OBJECTIVES: Solid lipid nanoparticles (SLNs), as a drug carrier, are a very attractive strategy for sustained and controlled drug release. In this study, we investigated the feasibility of SLNs to prolong the action of lidocaine for potential application in epidural anesthesia and analgesia. METHODS: Lidocaine-loaded SLNs were prepared with different lipids, including monostearin (MS), glyceryl palmitostearate (GP), and stearic acid (SA). The morphology and crystallinity were characterized with transmission electron microscopy and powder x-ray diffraction. In vitro release studies were carried in phosphate buffer solution of pH 7.4 using cellulose dialysis membrane. The in vivo efficacy of epidural anesthesia was evaluated in rats. RESULTS: Lidocaine was successfully incorporated in SLNs prepared with MS, GP, and SA, respectively. The particle sizes of lidocaine-loaded SLNs were 143 to 388 nm with polydispersity index of 0.29 to 0.45. Powder x-ray diffraction analysis showed that lidocaine was mainly dispersed in SLNs in an amorphous state. The in vitro release within 48 hrs showed that lidocaine released from SLNs was 80% with MS SLNs, 69% with GP SLNs, and 89% with SA SLNs. The epidural efficacy was compared with that of aqueous lidocaine HCl. Single injection of lidocaine SLN suspension produced epidural block for more than 8 hrs with MS SLNs, 12 hrs with GP SLNs, and 4 hrs with SA SLNs. ]The same dose of lidocaine in aqueous solution lasted for less than 2 hrs. CONCLUSIONS: Solid lipid nanoparticles can be exploited as a promising drug carrier for extending the action of lidocaine.
PMID: 22222687 [PubMed - as supplied by publisher]
Ultrasound-Guided Suprascapular Nerve Block, Description of a Novel Supraclavicular Approach.
Reg Anesth Pain Med. 2012 Jan 4;
Authors: Siegenthaler A, Moriggl B, Mlekusch S, Schliessbach J, Haug M, Curatolo M, Eichenberger U
Abstract
BACKGROUND AND OBJECTIVES: The suprascapular nerve (SSN) block is frequently performed for different shoulder pain conditions and for perioperative and postoperative pain control after shoulder surgery. Blind and image-guided techniques have been described, all of which target the nerve within the supraspinous fossa or at the suprascapular notch. This classic target point is not always ideal when ultrasound (US) is used because it is located deep under the muscles, and hence the nerve is not always visible. Blocking the nerve in the supraclavicular region, where it passes underneath the omohyoid muscle, could be an attractive alternative. METHODS: In the first step, 60 volunteers were scanned with US, both in the supraclavicular and the classic target area. The visibility of the SSN in both regions was compared. In the second step, 20 needles were placed into or immediately next to the SSN in the supraclavicular region of 10 cadavers. The accuracy of needle placement was determined by injection of dye and following dissection. RESULTS: In the supraclavicular region of volunteers, the nerve was identified in 81% of examinations (95% confidence interval [CI], 74%-88%) and located at a median depth of 8 mm (interquartile range, 6-9 mm). Near the suprascapular notch (supraspinous fossa), the nerve was unambiguously identified in 36% of examinations (95% CI, 28%-44%) (P < 0.001) and located at a median depth of 35 mm (interquartile range, 31-38 mm; P < 0.001). In the cadaver investigation, the rate of correct needle placement of the supraclavicular approach was 95% (95% CI, 86%-100%). CONCLUSIONS: Visualization of the SSN with US is better in the supraclavicular region as compared with the supraspinous fossa. The anatomic dissections confirmed that our novel supraclavicular SSN block technique is accurate.
PMID: 22222688 [PubMed - as supplied by publisher]
