Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2004
ReviewA review of intrathecal and epidural analgesia after spinal surgery in children.
In view of the overall experience regarding regional anesthetic techniques to control postoperative pain in infants and children, it is feasible that a similar efficacy and safety profile can be obtained when using such techniques after major orthopedic procedures such as anterior or posterior spinal fusion. I reviewed previous reports regarding the use of neuraxial techniques to provide analgesia after spine surgery in the pediatric population. ⋯ Variations of the analgesic technique include 1). the dose of the medications used; 2). the route of delivery (intrathecal or epidural); 3). the mode of delivery (single dose, intermittent bolus dosing, and continuous infusion); 4). the number of epidural catheters used (one versus two); 5). the medications infused (opioids, local anesthetics, or both); 6). the opioid used (morphine, fentanyl, hydromorphone); and 7). the analgesic regimen of the control group (intermittent "as needed" morphine or patient-controlled analgesia). Although limited data are available to document the analgesic superiority of these techniques over parenteral opioids, clinical data offer evidence of other benefits, including decreased intraoperative blood loss and quicker return of gastrointestinal function.
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Anesthesia and analgesia · Apr 2004
Randomized Controlled Trial Clinical TrialPreoperative oral dextromethorphan attenuated tourniquet-induced arterial blood pressure and heart rate increases in knee cruciate ligament reconstruction patients under general anesthesia.
The precise mechanism of tourniquet-induced arterial blood pressure increase is unknown. We determined the effect of preoperative oral dextromethorphan (DM) on arterial blood pressure and heart rate changes during tourniquet inflation in knee cruciate ligament reconstruction patients under general anesthesia. Patients in the DM group (n = 38) received oral DM 30 mg, and patients in the control group (n = 38) received oral placebo 2 h before the induction of anesthesia. Anesthesia was maintained with sevoflurane 2.0% and N(2)O in 33% oxygen, and the trachea was intubated until the end of surgery. Arterial blood pressure and heart rate were measured at 0, 30, and 60 min after the start of tourniquet inflation. Systolic arterial blood pressure and heart rate at 60 min in the control group were significantly more than those in the DM group (131.1 +/- 15.8 mm Hg versus 123.6 +/- 15.9 mm Hg [P < 0.05] and 74.1 +/- 11.3 bpm versus 67.8 +/- 8.5 bpm [P < 0.01], respectively). The percentage increase in systolic arterial blood pressure and heart rate in the DM group was also attenuated when compared with that in the control group (P < 0.05). In conclusion, preoperative oral DM 30 mg significantly attenuated arterial blood pressure and heart rate increases during tourniquet inflation under general anesthesia. ⋯ We demonstrated that preoperative oral dextromethorphan 30 mg significantly attenuated arterial blood pressure and heart rate increases at 60 min during tourniquet inflation in patients undergoing knee cruciate ligament reconstruction under general anesthesia.
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Anesthesia and analgesia · Apr 2004
Comparative StudyThe effects of pretreatment with lidocaine or bupivacaine on the spatial and temporal expression of c-Fos protein in the spinal cord caused by plantar incision in the rat.
We investigated the spatial and temporal patterns of c-Fos protein (Fos) expression in the dorsal horn of the spinal cord caused by plantar incision in the rat and the effects of pretreatment with local anesthetics. Bupivacaine (0.5%), lidocaine (2%), or saline for control was injected for nerve block and local infiltration before the plantar incision was made under anesthesia. Pain behavior and Fos expression in the L4-L5 segments of the spinal cord were assessed at 1, 3, 6, 24, 48, 72, and 120 h after the incision. The withdrawal threshold to mechanical stimulation decreased significantly at 1 h until 120 h (1-72 h, P < 0.01;120 h, P < 0.05), and pretreatment with local anesthetics increased the threshold significantly at 1 h (both groups: P < 0.01), 3 h (both groups: P < 0.01), and 6 h (bupivacaine, P < 0.01; lidocaine, P < 0.05) in comparison with that in the saline group. In the saline group, Fos expression was detected predominantly in laminae I-II and V-VI, and the total Fos expression was maximal at 1 h and then decreased gradually. Pretreatment with local anesthetics suppressed Fos expression significantly in all layers, and this suppression continued for several days. This study provides evidence of spatial and temporal changes in Fos expression induced by plantar incision. Our results indicate that although pretreatment with local anesthetics suppresses Fos expression for several days in the postoperative period, the analgesic effect is observed only for the expected duration of the local anesthetic used. ⋯ Prevention of early pain by pretreatment with local anesthetics provides little benefit for postoperative pain relief in the plantar incision model, although c-Fos expression is suppressed. The number of c-Fos-expressing neurons is not necessarily correlated with pain behavior.
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Anesthesia and analgesia · Apr 2004
Case ReportsUnusually low bispectral index values during emergence from anesthesia.
We observed unusually low BIS values during emergence from anesthesia apparently caused by misanalysis (as "suppression") of low voltage electroencephalogram. ⋯ When BIS values do not adequately correspond with clinical status, it is necessary to check raw electroencephalogram waveforms to more clearly characterize patient status.
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Lumbar epidural anesthesia and analgesia has gained increasing importance in perioperative pain therapy for abdominal and lower limb surgery. The loss-of-resistance technique, used to identify the epidural space, is thought to rely on the penetration of the ligamentum flavum. However, the exact morphology of the ligamentum flavum at different vertebral levels remains controversial. Therefore, in this study, we directly investigated the incidence of lumbar ligamentum flavum midline gaps in embalmed cadavers. Vertebral column specimens were obtained from 45 human cadavers. On each dissected level, ligamentum flavum midline gaps were recorded. The incidence of midline gaps per number of viable specimens at the following levels was: L1-2 = 10 of 45 (22.2%), L2-3 = 5 of 44 (11.4%), L3-4 = 5 of 45 (11.1%), L4-5 = 4 of 43 (9.3%), L5/S1 = 0 of 33 (0%). In conclusion, the present study determined the frequency of lumbar ligamentum flavum midline gaps. Gaps in the lumbar ligamentum flavum are most frequent between L1 and L2 but are more rare below this level. When using the midline approach, the ligamentum flavum may not impede entering the epidural space in all patients. ⋯ The ligamentum flavum is a crucial anatomical landmark for the safe performance of epidural anesthesia. However, the present study demonstrates some failure of the lumbar ligamentum flavum as a landmark. This may mean that, using a midline approach, one cannot always rely on the ligamentum flavum as a perceptible barrier to epidural needle advancement.