Women's acute anxiety variations before and after epidural anesthesia for childbirth.

OBJECTIVE: This study assessed changes in anxiety during different phases of childbirth in a sample of women demanding epidural anesthesia. DESIGN: Prospective, longitudinal case series. SAMPLE: A total of 133 women who demanded epidural anesthesia for childbirth answered the questionnaires. METHODS: Anxiety state was measured using the State Trait Anxiety Inventory (STAI) questionnaire. The STAI-S (anxiety state) was administered in three phases during childbirth: Phase 1 was before applying epidural anesthesia, Phase 2 was 45 min after the application of epidural anesthesia and Phase 3 was at less than 24 h after delivery. Data were collected in two general hospitals: a third-level public hospital and a well-recognized private hospital. MAIN OUTCOME MEASURES: STAI scores. RESULTS: Anxiety state decreases significantly after applying the epidural anesthesia (Phase 2) compared to before anesthesia (Phase 1), and it remains low levels 24 h after childbirth (Phase 3). There were statistically significant differences in STAI scores between the different phases administrated (Phases 1 and 2: p < 0.001; effect size, d = 1.40; Phases 1 and 3: p < 0.001; effect size, d = 1.39). In Phase 3, women with cesarean section birth had significant differences in STAI scores relative to those with spontaneous birth (p = 0.037; d = 0.44). The type of health-care setting (public or private), the educational level and the numbers of previous births does not affect the level of anxiety state in women in any of the three phases. CONCLUSIONS: Women's anxiety decreases significantly after applying epidural anesthesia, and it remains low 24 h after delivery. Anxiety against childbirth was not influenced by the health system used by women, by the condition of primiparous or multiparous, or by the educational level. Women who received an epidural anesthesia with a cesarean section reported higher rates of anxiety state after birth.

Sugammadex, a neuromuscular blockade reversal agent, causes neuronal apoptosis in primary cultures.

Sugammadex, a γ-cyclodextrin that encapsulates selectively steroidal neuromuscular blocking agents, such as rocuronium or vecuronium, has changed the face of clinical neuromuscular pharmacology. Sugammadex allows a rapid reversal of muscle paralysis. Sugammadex appears to be safe and well tolerated. Its blood-brain barrier penetration is poor (< 3% in rats), and thus no relevant central nervous toxicity is expected. However the blood brain barrier permeability can be altered under different conditions (i.e. neurodegenerative diseases, trauma, ischemia, infections, or immature nervous system). Using MTT, confocal microscopy, caspase-3 activity, cholesterol quantification and Western-blot we determine toxicity of Sugammadex in neurons in primary culture. Here we show that clinically relevant sugammadex concentrations cause apoptotic/necrosis neuron death in primary cultures. Studies on the underlying mechanism revealed that sugammadex-induced activation of mitochondria-dependent apoptosis associates with depletion of neuronal cholesterol levels. Furthermore SUG increase CytC, AIF, Smac/Diablo and CASP-3 protein expression in cells in culture. Potential association of SUG-induced alteration in cholesterol homeostasis with oxidative stress and apoptosis activation occurs. Furthermore, resistance/sensitivity to oxidative stress differs between neuronal cell types.

Antioxidants and gabapentin prevent heat hypersensitivity in a neuropathic pain model.

BACKGROUND: The involvement of voltage-dependent calcium channels and reactive oxygen species in the pathophysiology of neuropathic pain might justify the preventative administration of antioxidant enzymes, at low doses, in combination with gabapentin (GaP) to maximize its analgesic effect in an experimental model of neuropathic pain in rats. METHODS: This work investigated the analgesic effects of these drugs, alone or in combination, by intraperitoneal administration for three consecutive days before (Series I) or after (Series II) a peripheral neuropathy induced by left sciatic nerve ligation. A prospective randomized study was conducted using 96 Wistar rats (50 males and 46 females). Mechanical hypersensitivity was measured with a dynamic plantar anesthesiometer. A hot plate analgesia meter calculated the thermal sensitivity. Side effect profiles for drug combinations were evaluated with a conventional scale to assess levels of sedation interfering with postural control and righting reflexes. RESULTS: Preinjury administration (Series I) of GaP alone prevented the development of mechanical hypersensitivity at the nerve-damage hind paw. When GaP was administered concurrently with superoxide dismutase and catalase, its preventive analgesic effect did not increase. Antioxidants administered alone were completely ineffective at modulating the mechanical or thermal hypersensitivity. When treatments were only delivered following surgery (Series II), only the group receiving combined GaP and antioxidants treatment prior to nerve injury showed higher thermal thresholds from postsurgery days 7-30. CONCLUSIONS: These results suggest that preventive antioxidants in combination with GaP provided a synergistic suppression of thermal hypersensitivity that GaP alone cannot produce.

Electromyographic thresholds after thoracic screw stimulation depend on the distance of the screw from the spinal cord and not on pedicle cortex integrity.

BACKGROUND CONTEXT: Present studies concerning the safety and reliability of neurophysiological monitoring during thoracic pedicle screw placement remain inconclusive, and therefore, universally validated threshold levels that confirm osseous breakage of the instrumented pedicles have not been properly established. PURPOSE: The objective of this work was to analyze whether electromyographic (EMG) thresholds, after stimulation of the thoracic pedicle screw, depend on the distance between the neural structures and the screws. The modifier effect of different interposed tissues between a breached pedicle and neural structures was also investigated. STUDY DESIGN: This experimental study uses a domestic pig model. METHODS: Electromyographic thresholds were recorded after the stimulation of 18 thoracic pedicle screws that had been inserted into five experimental animals using varying distances between each screw and the spinal cord (8 and 2 mm). Electromyographic thresholds were also registered after the medial pedicle cortex was broken and after different biological tissues were interposed (blood, muscle, fat, and bone) between the screw and the spinal cord. RESULTS: Mean EMG thresholds increased to 14.1±5.5 mA for screws with pedicle cortex integrity that were placed 8 mm away from the dural sac. After the medial pedicle cortex was broken and without varying the distance of the screw to the dural sac, the mean EMG thresholds were not appreciably changed (13.6±6.3 mA). After repositioning the screw at a distance of 2 mm from the spinal cord and after medial cortical breach of the pedicle, the mean threshold significantly slowed to 7.4±3.4 mA (p<.001). When the screw was placed in contact with the spinal dural sac, even lower EMG thresholds were registered (4.9±1.9, p<.001). Medial pedicle cortex rupture and the interposition of different biological tissues in experimental animals did not alter the stimulation thresholds of the thoracic pedicle screws. CONCLUSIONS: In the experimental animals, the observed electrical impedance depended on the distance of screws from the neural structures and not on the integrity of the pedicle cortex. The screw-triggered EMG technique did not reliably discriminate the presence or absence of bone integrity after pedicle screw placement. The response intensity was not related to the type of interposed tissue.

Metabolic muscle damage and oxidative stress markers in an America's Cup yachting crew.

Activities of enzymes involved in muscle damage [creatine kinase (CK) and aspartate aminotransferase (AST)] and levels of malondialdehyde (MDA) as a marker of oxidative stress were monitored in the plasma of 27 members of an America's Cup yachting crew. The preventive benefits of allopurinol on muscle damage were also tested. In racing period A, the crew was divided into two groups according to their tasks on board. Blood samples from all 27 sailors were obtained before the start of a 5-day fleet race, after the last race, and after the ten match races. In period B, crew members were divided at random into two groups. One group (13 participants) received 300 mg/day of allopurinol 3 h before racing. The other ten members received placebo. Blood samples were collected just before and after the second round of the Louis Vuitton Cup. All participants showed increased CK and AST activities after the racing period A. The increase in CK activity was highest in sailors involved in strenuous physical work. At the end of period A, plasma MDA levels were higher in all participants as compared with non-participant athletes. In period B, a significant decrease in CK activity, but not in AST, appeared among participants receiving allopurinol. Plasma MDA decreased in sailors treated with allopurinol, but this reduction did not reach statistical significance. America's Cup is a sailing sport with high physical demands, as shown by the increase in muscle-damage markers. Treatment with allopurinol appeared to decrease the levels of muscle damage markers.

Ultrasound guidance for lateral midfemoral sciatic nerve block: a prospective, comparative, randomized study.

Block of the sciatic nerve at the midfemoral level is usually performed using nerve stimulation techniques. We investigated the efficacy of ultrasound, combined with nerve stimulation, to locate and block the sciatic nerve at the lateral midfemoral level compared to nerve stimulation alone. Sixty-one patients scheduled for foot and ankle surgery were enrolled in this prospective, randomized study. Thirty patients underwent a lateral block of the sciatic nerve at the midfemoral level guided by ultrasound (group US) and 31 patients received the block without ultrasound (group ES). Once an adequate motor response was obtained using nerve stimulation, 35 mL of ropivacaine 0.5% was administered. The main end-points of the study were: number of attempts to obtain an adequate motor response, success rate of nerve location at the first attempt, quality and duration of both sensory and motor blocks, and anesthetic distribution. The success of sciatic nerve location at the first attempt was significantly more frequent in the US group than in the ES group (76.6% versus 41.9%; P < 0.001). The quality of the sensory block and the tolerance to the pneumatic tourniquet were also significantly better in the US group (P < 0.01). We conclude that ultrasound combined with nerve stimulation improved the quality of the sensory block and the tolerance to the pneumatic tourniquet, reducing the number of attempts to perform sciatic nerve block at the midfemoral level.

A comparison of lateral popliteal versus lateral midfemoral sciatic nerve blockade using ropivacaine 0.5%.

BACKGROUND AND OBJECTIVES: The midfemoral approach to the sciatic nerve (MF) is a new technique that has been used for postoperative analgesia after knee surgery. The aim of the present study was to compare efficacy, performance time, and patient acceptance of the midfemoral approach to that of the lateral approach at the level of the popliteal fossa (popliteal block [PB]). METHODS: Sixty-three patients were enrolled in this prospective, randomized study. Thirty-two patients received a lateral sciatic nerve block (group PB) and 31 patients a midfemoral block (group MF). Ropivacaine 0.5% (30 mL) was used in both groups. RESULTS: The quality of nerve blockade was comparable in both groups. Onset of sensory block for peroneal and tibial nerves was significantly shorter in group MF than in group PB, 5 (1-20) minutes and 5 (1-20) minutes versus 10 (1-40) minutes and 10 (1-45) minutes, respectively. Onset of motor block in both territories was also shorter in group MF compared with PB, 6 (2-35) minutes and 5 (2-55) minutes versus 15 (2-60) minutes and 15 (2-60) minutes, respectively (P <.05). There was no difference in duration of sensory and motor blockade, 16 (7-32) hours versus 16 (6-43) hours and 16 (8-32) hours versus 16 (6-25) hours. There was no significant difference between both groups with respect to difficulty of nerve block performance. Patient discomfort during needle puncture was also similar. CONCLUSIONS: The midfemoral approach to the sciatic nerve for ankle and foot surgery resulted in a reliable anesthetic, comparable to that of the lateral popliteal approach. This technique is simple, safe, and provides postoperative analgesia as effective as that obtained with the lateral approach.