Intravenous diclofenac and orphenadrine for the treatment of postoperative pain after remifentanil-based anesthesia : A double-blinded, randomized, placebo-controlled study.

BACKGROUND: Postoperative intravenous diclofenac reduces patient opioid demand and is commonly used in surgical units. Orphenadrine is mainly used in combination with diclofenac for musculoskeletal injuries and postoperative pain control. The objective of this study was to compare the analgesic efficacy of diclofenac-orphenadrine, diclofenac alone and saline. METHODS: We performed a double-blind, randomized, placebo-controlled, parallel-group, single-center clinical study investigating the opioid-sparing effect of a combination of diclofenac and orphenadrine versus diclofenac alone versus isotonic saline solution. Initially 72 patients were included and received total intravenous anesthesia during cruciate ligament surgery. All patients were postoperatively treated with a patient-controlled analgesia (PCA) device containing hydromorphone. Pharmacological safety was assessed by laboratory parameters, vital signs, and delirium detection scores. RESULTS: There was no significant difference between the groups in cumulative dose of PCA analgesics required after 24 h postsurgery, with 5.90 mg (SD ± 2.90 mg) in the placebo group, 5.73 mg (SD ± 4.75 mg) in the diclofenac group, and 4.13 mg (SD ± 2.57 mg) in the diclofenac-orphenadrine group. Furthermore, there was no significant difference between the groups in cumulative dose of PCA analgesics required 2 h postsurgery (n = 65). Mean dose of hydromorphone required after 2 h was 1.54 mg (SD ± 0.57 mg) in the placebo group, 1.56 mg (SD ± 1.19 mg) in the diclofenac-only group, and 1.37 mg (SD ± 0.78 mg) in the diclofenac-orphenadrine group. However, when comparing the diclofenac-orphenadrine group and the diclofenac group combined to placebo there was a significant reduction in PCA usage in the first 24 h postsurgery. In total, there were 25 adverse events reported, none of which were rated as severe. CONCLUSION: Orphenadrine-diclofenac failed to significantly reduce postoperative opioid requirements. However, in an exploratory post hoc analysis the diclofenac-orphenadrine and the diclofenac group combined versus placebo showed a tendency to reduce opioid demand in postoperative pain control. Further research is required to determine the value of orphenadrine as an adjuvant in a multimodal approach for postoperative pain management.

Comparison of cooling and EMLA to reduce the burning pain during capsaicin 8% patch application: a randomized, double-blind, placebo-controlled study.

Topical capsaicin 8% was developed for the treatment of peripheral neuropathic pain. The pain reduction is associated with a reversible reduction of epidermal nerve fiber density (ENFD). During its application, topical capsaicin 8% provokes distinct pain. In a randomized, double-blind study analyzed with a block factorial analysis of variance, we tested whether cooling the skin would result in reliable prevention of the application pain without inhibiting reduction of ENFD. A capsaicin 8% patch was cut into 4 quarters and 2 each were applied for 1 hour on the anterior thighs of 12 healthy volunteers. A randomization scheme provided for 1 of the application sites of each thigh to be pretreated with EMLA and the other with placebo, whereas both application sites of 1 thigh, also randomly selected, were cooled by cool packs, resulting in a site temperature of 20°C during the entire treatment period. The maximum pain level given for the cooled sites (visual analogue scale [VAS] 1.3 ± 1.4) proved to be significantly lower than for the non-cooled sites (VAS 7.5 ± 1.9) (P < .0001). In contrast, there was no significant difference in application pain between the sites pretreated with EMLA or with placebo (VAS 4.1 ± 3.6 vs 4.8 ± 3.5, P = .1084). At all application sites, ENFD was significantly reduced by 8.0 ± 2.8 (ENF/mm ± SD, P < .0001), that is, 70%, with no significant differences between the sites with the different experimental conditions. In conclusion, cooling the skin to 20°C reliably prevents the pain from capsaicin 8% patch application, whereas EMLA does not. ENFD reduction is not inhibited by cooling.

Perioperative auricular electroacupuncture has no effect on pain and analgesic consumption after third molar tooth extraction.

BACKGROUND: Auricular acupuncture (AA) has been shown to alleviate acute and chronic pain. We investigated the effects of auricular electroacupuncture (AE) on pain and analgesic drug consumption in the first 48 h after unilateral mandibular third molar tooth extraction under local anesthesia in a prospective, randomized, double-blind, placebo-controlled study in 149 patients. METHODS: Patients received either AA with electrical stimulation (AE, n = 76) or without (AA, n = 37) electrical stimulation at an alternating frequency of 2/100 Hz or a sham AE with metal plates instead of needles and no electrical stimulation, no-needle (NN, n = 36) at the AA points 1 (tooth), 55 (Shen men) and 84 (mouth) during the entire study period. Regularly rated pain intensity (five-point verbal rating scale), consumption of acetaminophen 500 mg tablets and additional rescue medication with mefenamic acid 500 mg were assessed. RESULTS: The median fraction of time when pain was rated as moderate or worse (upper and lower quartile): AE: 33% (12%, 64%), AA: 22% (6%, 56%), NN: 30% (7%, 53%) did not differ significantly among the treatment groups. There were no significant differences in mean number of acetaminophen 500 mg tablets (range): AE: 5.2 (0-12), AA: 4.6 (0-11), NN: 5.4 (0-10) or percentage of patients requiring additional mefenamic acid: AE: 19%, AA: 18%, NN: 19%. CONCLUSION: We conclude that neither AE nor AA alone reduce either pain intensity or analgesic consumption in a molar tooth extraction model of acute pain.

Age-dependent changes of the periodontal ligament in rats.

Even after the end of the natural tooth eruption, there is a continuous renewal of the periodontal collagenous fiber system, depending on functional demands. The aim of this study was to analyse the age-dependent changes and regional differences of the collagen renewal rate of the periodontal ligament in healthy rats. The study was performed by autoradiography of the molars of rats aged 1, 8, and 18 months, where collagen was labelled by intravenously applied 3H-proline. After an 8-hour incorporation period, the animals were killed. For comparative examinations, molar roots were subdivided into cervical, middle, and apical thirds. Structural and quantitative analyses were performed by light microscopy and autoradiography, using an image-analysing computer-assisted operating unit that determined the 3H-proline-labelled collagen by photometry based on extinction measurement. With increasing age of the animals, the number of silver grains (3H-proline-blackened collagen) was reduced and the quantitative evaluation indicated a reduction of 3H-proline in the periodontal ligament. The lowest level of 3H-proline activities was observed in the middle, and the highest level in the apical root third, independent of age. All preparations revealed condensations of silver grains, which were located in the region of the periodontal ligament adjacent to the alveolar bone, but did not reveal any preferred position with regard to the dental topography. With progressive age, the uptake of 3H-proline in the periodontal ligament was reduced by about 20 to 30%, a result that corresponds to a decrease in collagenous fiber production. Collagen was mainly formed in the apical and cervical root third, starting from the alveolar bone side, presumably in response to functional strain.

Lymph drainage in the human dental pulp.

We investigated which structural components are responsible for maintaining interstitial fluid equilibrium in the pulpal tissue, for which the existence of an effective lymph drainage is postulated. There have been only a small number of investigations on pulpal lymph tissue. Therefore, we decided to perform a detailed structural analysis. Twenty vital, healthy teeth that had to be extracted for orthodontic reasons were immersed in Patent Blue for 10 to 15 minutes after opening the pulpal cavity. They were then extracted and the dental pulps were opened by cleavage of the surrounding hard tooth structure. Subsequently, the specimens were prepared for light and electron microscopic investigation. A clear blue ring of stain was detected by light microscopy in Weil's zone in the coronal region of the pulp, the cell-rarefied layer surrounded by the odontoblasts. No dye deposition was observed in the apical part. However, using transmission electron microscopy, capillary structures with typical morphological characteristics of lymphatic vessels were found apically. The coronal part of the pulp did not reveal any such vascular structures. It may be concluded from these findings that the lymph in the coronal region is collected in interstitial tissue clefts and drained towards the apex, whence it is further transported via lymph capillaries.

The color change in CO2 absorbents on drying: an in vitro study using moisture analysis.

UNLABELLED: Alkali hydroxide-free absorbents change color markedly when they dry, whereas absorbents containing alkali hydroxides do not. We investigated whether this observation can be explained by the weaker hygroscopic properties of pure calcium hydroxide compared with alkali hydroxides. Samples of the alkali hydroxide-free absorbents Amsorb or Superia and samples of these two absorbents with 1% or 3% NaOH or 3% KOH added were dried in a moisture analyzer at 105 degrees C to determine their moisture content and to assess the color of the samples during drying (each group, n = 5). Additionally, we repeated the experiments with pulverized samples of Baralyme and Spherasorb, which contain approximately 4% KOH and 1% NaOH, respectively. Amsorb and Superia changed color long before they were dry. After the addition of 1% NaOH, and as with the Spherasorb samples, the drying time required for a color change was longer, and the intensity of the resulting violet was less. This effect was even stronger when 3% NaOH was added. The samples with added KOH and the Baralyme did not change color at all on drying. We conclude that the differences in color change on drying in absorbents with varying NaOH or KOH content cannot be explained by larger water retention because of the hygroscopic properties of the alkali hydroxides. IMPLICATIONS: In an in vitro study, the moisture content and color change on drying were determined in samples of Amsorb or Superia and in the same absorbents with added NaOH or KOH. With increasing concentrations of alkali hydroxide, a delay in the color change upon drying was observed. However, the moisture content did not change.

Intrathecal temperature is closely reflected by the aortic, but not by the rectal, temperature in a rabbit model of spinal cord ischemia.

IMPLICATIONS: Experimental ischemic lesions in the lumbar spinal cord of the rabbit can be induced by inflating the balloon of a Swan-Ganz catheter in the abdominal aorta. The intrathecal temperature is significantly better reflected by the temperature from the thermistor of the catheter than by the rectal temperature.

Leprosy affects facial nerves in a scattered distribution from the main trunk to all peripheral branches and neurolysis improves muscle function of the face.

Current literature rejects nerve release in leprous facial neuropathy and states that lesions are restricted to the peripheral zygomatic branches. Since there are approximately 500,000 patients with this disease throughout the world, we wanted to clarify the precise location of facial nerve's affection and the benefit of neurolysis. Our study showed that in patients with leprosy, the facial nerve's main trunk, the peripheral zygomatic branches, and all other branches were affected. Follow-up showed improvement in lagophthalmos and in misreinnervation, with no improvement in the control cohort. Nerve release improves muscle function in leprous facial neuropathy, provided surgery is performed on all affected segments. Intraoperative electroneurodiagnostics is an effective tool for detecting the most proximal site of lesion and ensuring effective surgery.

Leprosy affects facial nerves in a scattered distribution from the main trunk to all peripheral branches and neurolysis improves muscle function of the face

Current literature rejects nerve release in leprous facial neuropathy and states that lesions are restricted to the peripheral zygomatic branches. Since there are approximately 500,000 patients with this disease throughout the world, we wanted to clarify the precise location of facial nerve's affection and the benefit of neurolysis. Our study showed that in patients with leprosy, the facial nerve's main trunk, the peripheral zygomatic branches, and all other branches were affected. Follow-up showed improvement in lagophthalmos and in misreinnervation, with no improvement in the control cohort. Nerve release improves muscle function in leprous facial neuropathy, provided surgery is performed on all affected segments. Intraoperative electroneurodiagnostics is an effective tool for detecting the most proximal site of lesion and ensuring effective surgery.

Small carbon monoxide formation in absorbents does not correlate with small carbon dioxide absorption.

UNLABELLED: In this study we sought to determine whether an absorbent in which little carbon monoxide (CO) forms has a correspondingly small capacity to absorb carbon dioxide (CO(2)). Completely dried samples (600 g) of Baralyme (A), Drägersorb 800 (B), Drägersorb 800 Plus (C), Intersorb (D), Spherasorb (E), LoFloSorb (F), Superia (G), and Amsorb (H) were exposed to a flow of 0.5% (A-H; n = 4-5) and 4% isoflurane (F-H; n = 3) in pure oxygen at 5 L/min for 60 min. Downstream CO concentration, temperature, and isoflurane concentration were recorded every 60 s to calculate CO formation and isoflurane loss. The CO(2) absorption capacity of each brand was determined by passing 5.1% CO(2) in oxygen (flow, 250 mL/min) through untreated samples (30 g; n = 5) until the outlet CO(2) concentration reached 0.5%. CO formation was largest in absorbents containing potassium hydroxide (A and B) and negligible in absorbents not containing any alkali hydroxide (F-H). The outlet temperature correlated with CO formation, but the isoflurane loss did not. The duration of CO(2) absorption also did not correlate with CO formation. We conclude that absorbents that allow only very little CO formation are not necessarily poor CO(2) absorbents. IMPLICATIONS: In an in vitro study, carbon dioxide (CO(2)) absorption capacity and possible carbon monoxide (CO) formation were tested in different absorbent brands. Absorbents with very small CO formation are not necessarily poor CO(2) absorbents.

Using amsorb to detect dehydration of CO2 absorbents containing strong base.

BACKGROUND: Because Amsorb changes color when it dries, the authors investigated whether Amsorb combined with different strong base-containing carbon dioxide absorbents signals dehydration of such absorbents. METHODS: Five different carbon dioxide absorbents (1,330 g) each topped with 70 g of Amsorb were dried in an anesthesia machine (Modulus CD, Datex-Ohmeda, Madison, WI) with oxygen (Amsorb layer at the fresh gas inflow site). As soon as a color change was detected in the Amsorb, the authors tested the samples for a change in weight and carbon monoxide formation from 7.5% desflurane or 4% isoflurane. In a different experiment with the five absorbents, Amsorb was layered at the drying gas outflow site. In further experiments, the authors tested for a color change in Amsorb from drying and rehydrating and from drying with nitrogen. Finally, they dried a mixture of Amsorb and 1% NaOH and examined it for color change. RESULTS: In the experiments with Amsorb layered at the inflow, the Amsorb changed color when the water content of the samples was only marginally reduced (to a mean 13.6%), and no carbon monoxide formed. With Amsorb layered at the outflow, it changed color when the mean water content of the samples was reduced to 8.8%, and carbon monoxide formation was detected to varying degrees. The color change was independent of the drying gas and could be reversed by rehydrating. Adding NaOH to Amsorb prevented a color change. CONCLUSIONS: Dehydration in strong base-containing absorbents can reliably be indicated before carbon monoxide is formed when Amsorb is layered at the fresh gas inflow. The authors assume that the indicator dye in Amsorb changes color on drying because of the absence of strong base in this absorbent.