A multifactorial analysis to explain inadequate surgical analgesia after extradural block

A multivariate analysis of inadequate extradural analgesia was carried out prospectively on 1051 patients undergoing lumbar extradural anaesthesia for surgery performed on structures innervated by T10-S5. Ninety-six patients (9%) experienced pain during surgery. Age, extradural fentanyl, diazepam sedation and duration of surgery had no significant influence. We found some weak evidence that the type of surgery affects the risk of feeling pain. The probability of pain increased with increasing weight, except in overweight women, and was significantly greater for both shorter and taller patients, relative to patients of average height. The probability of pain decreased with increasing dose of local anaesthetic, increasing spread of extradural analgesia, addition of adrenaline, and fentanyl or thiopentone sedation. In conclusion, patient-, surgery- and anaesthesia-related factors influence the risk of inadequate extradural analgesia. If such factors are taken into account, an increase in the success rate may be anticipated.      

Ultrasound in anesthesiology--ultrasound in interventional pain therapy

Ultrasound is an emerging new imaging and guiding technique for diagnostic or therapeutic interventional pain procedures. Advantages are the real time monitoring of the targeted structures, the placement of the instruments and the visualization of local anaesthetic spread without exposing patients and personal to radiation. Pain specialists need a large anatomical knowledge and training to use the new method safely and distinctively. The increasing published data available and the personal experience of the authors suggest a potential usefulness in interventional pain therapy, but also limitations.     

Sonographic visualization and ultrasound-guided block of the third occipital nerve: prospective for a new method to diagnose C2-C3 zygapophysial joint pain

BACKGROUND: Chronic neck pain after whiplash injury is caused by cervical zygapophysial joints in 50% of patients. Diagnostic blocks of nerves supplying the joints are performed using fluoroscopy. The authors' hypothesis was that the third occipital nerve can be visualized and blocked with use of an ultrasound-guided technique. METHODS: In 14 volunteers, the authors placed a needle ultrasound-guided to the third occipital nerve on both sides of the neck. They punctured caudal and perpendicular to the 14-MHz transducer. In 11 volunteers, 0.9 ml of either local anesthetic or normal saline was applied in a randomized, double-blind, crossover manner. Anesthesia was controlled in the corresponding skin area by pinprick and cold testing. The position of the needle was controlled by fluoroscopy. RESULTS: The third occipital nerve could be visualized in all subjects and showed a median diameter of 2.0 mm. Anesthesia was missing after local anesthetic in only one case. There was neither anesthesia nor hyposensitivity after any of the saline injections. The C2-C3 joint, in a transversal plane visualized as a convex density, was identified correctly by ultrasound in 27 of 28 cases, and 23 needles were placed correctly into the target zone. CONCLUSIONS: The third occipital nerve can be visualized and blocked with use of an ultrasound-guided technique. The needles were positioned accurately in 82% of cases as confirmed by fluoroscopy; the nerve was blocked in 90% of cases. Because ultrasound is the only available technique today to visualize this nerve, it seems to be a promising new method for block guidance instead of fluoroscopy.     

Motor examination in children with Attention-deficit/hyperactivity Disorder and Asperger Syndrome

Aim: Evaluating whether motor skills could differentiate drug‐naive subjects with two neurodevelopmental disorders: Attention‐Deficit Hyperactivity Disorder (ADHD) and Asperger Syndrome (AS). Methods: Thirty‐six boys (12 with ADHD, 12 with AS and 12 with typical development) aged 8–12 were evaluated using the Physical and Neurological Examination for Subtle Signs. Three primary outcome variables were obtained as follows: (i) total speed of timed activities, (ii) total overflow and (iii) total dysrhythmia. Results: Children with AS performed more slowly than those with ADHD and healthy children independently of age and IQ. Total dysrhythmia differentiates ADHD and AS children from controls. Conclusion: Dysfunction of the fronto‐striatal–cerebellar networks related to motor control could be the physiopathological basis of the reported findings.     

Long pentraxin 3: a marker of inflammation in untreated psoriatic patients

Psoriasis is a common cutaneous disorder characterized by abnormal epidermal differentiation, proliferation and inflammation mediated by dermal infiltrates, such as T cells, neutrophils, dendritic cells and macrophages. There are renewed interest in the role of components of the innate immune system. Cytokines such as tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6, and -1beta involved in pathogenic phenomena in psoriasis are known as inducers of the acute phase response. Among the large group of acute phase reactants, C-reactive protein (CRP) and fibrinogen are of special interest in psoriasis. The PTX-3, a long pentraxin sharing similarities with the classical short proteins. Thus, considering the numerous biological roles of inflammatory cytokines and their relationship with inflammatory markers, such as CRP and fibrinogen we have investigated the role of PTX3 in psoriasis. To this aim PTX3, TNF-alpha, IL-6 and IL-1beta in plasma and in monocytic cultures by enzyme linked immunosorbent assay (ELISA) in 44 patients including severe and mild psoriasis were measured. An increased production of PTX3, both in supernatant of purified monocytes and in plasma from patients with severe psoriasis, was found. The significant correlation, between cellular production and plasma levels of PTX3 in psoriasis was found as a sign of cellular activation by monocytes/macrophages that first infiltrate the psoriatic lesion. In severe psoriasis, a significant correlation between psoriasis area and severity index (PASI) score and TNF-alpha and IL-6 levels in both supernatant of monocytes and plasma was found. In contrast, no correlation was found for IL-1beta. By immunohistochemistry and immunofluorescence, a strong PTX3 staining in fibroblasts, endothelial cells and monocytes/macrophages in severe psoriatic lesional skin was detected. Finally, a positive correlation between PTX3 and disease activity of psoriasis was observed as PASI score was elevated. These findings suggest that PTX3 could be used as a further marker of disease activity of psoriasis.     

Ranking of parameters of pain hypersensitivity according to their discriminative ability in chronic low back pain

Low back pain is associated with plasticity changes and central hypersensitivity in a subset of patients. We performed a case-control study to explore the discriminative ability of different quantitative sensory tests in distinguishing between 40 cases with chronic low back pain and 300 pain-free controls, and to rank these tests according to the extent of their association with chronic pain. Gender, age, height, weight, body mass index, and psychological measures were recorded as potential confounders. We used 26 quantitative sensory tests, including different modalities of pressure, heat, cold, and electrical stimulation. As measures of discrimination, we estimated receiver operating characteristics (ROC) and likelihood ratios. Six tests seemed useful (in order of their discriminative ability): (1) pressure pain detection threshold at the site of most severe pain (fitted area under the ROC, 0.87), (2) single electrical stimulation pain detection threshold (0.87), (3) single electrical stimulation reflex threshold (0.83), (4) pressure pain tolerance threshold at the site of most severe pain (0.81), (5) pressure pain detection threshold at suprascapular region (0.80), and (6) temporal summation pain threshold (0.80). Pressure and electrical pain modalities seemed most promising and may be used for diagnosis of pain hypersensitivity and potentially for identifying individuals at risk of developing chronic low back pain over time.     

Effect of intravenous tropisetron on modulation of pain and central hypersensitivity in chronic low back pain patients

The activation of 5-hydroxytryptamine-3 (5-HT-3) receptors in spinal cord can enhance intrinsic spinal mechanisms of central hypersensitivity, possibly leading to exaggerated pain responses. Clinical studies suggest that 5-HT-3 receptor antagonists may have an analgesic effect. This randomized, double-blind, placebo-controlled crossover study tested the hypothesis that the 5-HT-3 receptor antagonist tropisetron attenuates pain and central hypersensitivity in patients with chronic low back pain. Thirty patients with chronic low back pain, 15 of whom were women (aged 53 ± 14 years) and 15 men (aged 48 ± 14 years), were studied. A single intravenous injection of 0.9% saline solution, tropisetron 2 mg, and tropisetron 5 mg was administrated in 3 different sessions, in a double-blind crossover manner. The main outcome was the visual analogue scale (VAS) score of spontaneous low back pain before, and 15, 30, 60, and 90 minutes after drug administration. Secondary outcomes were nociceptive withdrawal reflexes to single and repeated electrical stimulation, area of reflex receptive fields, pressure pain detection and tolerance thresholds, conditioned pain modulation, and area of clinical pain. The data were analyzed by analysis of variance and panel multiple regressions. All 3 treatments reduced VAS scores. However, there was no statistically significant difference between tropisetron and placebo in VAS scores. Compared to placebo, tropisetron produced a statistically significant increase in pain threshold after single electrical stimulation, but no difference in all other secondary outcomes was found. A single-dose intravenous administration of tropisetron in patients with chronic low back pain had no significant specific effect on intensity of pain and most parameters of central hypersensitivity.