Guidelines for the safe clinical practice of peripheral nerve blocks in the adult patient

The Peripheral Nerve Block working group of the Belgian Association for Regional Anesthesia has revised and updated the “Clinical guidelines for the practice of peripheral nerve block in the adult” which were published in 2013.

A prospective randomized double-blind trial of the efficacy of a bilateral lumbar erector spinae block on the 24h morphine consumption after posterior lumbar inter-body fusion surgery

BACKGROUND

Spine surgery is associated with considerable postoperative pain and can be challenging to treat. A loco-regional technique suitable for spine surgery should cover the dorsal root of the spinal nerves at the levels where surgery is performed. The erector spinae block is a loco-regional technique with promising results and was recently described at the thoracic level. There are no randomized trials of this technique on a lumbar level. This study tests the hypothesis that the 24-h postoperative morphine consumption is significantly lower in patients undergoing posterior lumbar inter-body fusion surgery with a lumbar erector spinae (LUMBES) block when compared with a sham block.

METHODS

This prospective randomized double-blind multicenter study will randomly allocate 80 adult patients undergoing elective posterior lumbar inter-body fusion surgery during general anesthesia to one of two groups as follows: (1) bilateral erector spinae block (20 mL 0.25% levobupivacaine) or (2) bilateral sham block (20 mL NaCl 0.9%). Our primary endpoint is 24-h postoperative morphine consumption. Secondary endpoints include 72-h morphine consumption, intraoperative sufentanil dosage, postoperative pain scores at regular time intervals both at rest and during movement, time to first postoperative mobilization, and the Quality of Recovery 40 survey score.

DISCUSSION

The LUMBES trial is a pragmatic clinical study that will provide evidence of whether a bilateral lumbar erector spinae block is effective in reducing 24-h postoperative morphine consumption in patients undergoing lumbar inter-body fusion surgery. If this hypothesis is confirmed, this finding could contribute to more widespread implementation of this technique.

TRIAL REGISTRATION

Local ethics committee B300201837508, ClinicalTrials.gov identifier: NCT03825198 . Registered on 31 Jan 2019.

Regional versus general anesthesia for spine surgery. A comprehensive review

The use of regional anesthesia techniques for intra-operative anesthesia remains very controversial for patients scheduled to undergo spinal interventions. Spine surgery is still mostly performed under general anesthesia. This has to be explained by the patient's position required during surgery, the extent and duration of some procedures, the preference of the surgeon and/or anesthesiologist and a trend which becomes more and more prominent to abandon central nerve blocks in general. The presence of foreign material in the neighborhood of the surgical field may be a reason for surgeons to refuse such techniques. Nevertheless, during the last decade the available literature has increased progressively in support of regional anesthesia for these interventions. The present overview will focus on the feasibility of different regional techniques to be used intra-operatively. These techniques may also be of interest or even intended for prolonged postoperative analgesia and benefit even after a single bolus injection, continuous or intermittent administration. Although all techniques described offered favorable success rates, future research is mandatory to determine their superiority over general intra-operative anesthesia and conventional pain therapy.

Magnetism in bcc and fcc Fe with carbon and manganese

Density functional theory calculations were performed to study the structure and magnetic properties of bcc (α) and fcc (γ) Fe with 3 at.% carbon and manganese impurities. We find that all bcc-based Fe, Fe-C and Fe-Mn-C phases exhibit a ferromagnetic (FM) ground state, while the antiferromagnetic double-layer (AFMD) state is lowest in energy within the collinear spin approach in fcc Fe, Fe-C and Fe-Mn-C phases. However, the carbon and manganese impurities affect the local magnetic interactions significantly. The states with opposite manganese magnetic moments are quasi-degenerate in bcc Fe-Mn alloy, whereas octa-site carbon stabilizes ferromagnetic coupling of the nearest manganese atom with the Fe host. We demonstrate that the antiferromagnetic (AFM) fcc Fe-C and Fe-Mn-C alloys are intrinsically inhomogeneous magnetic systems. Carbon frustrates the local magnetic order by reorientation of magnetic moments of the nearest Mn and Fe atoms, and favors their ferromagnetic coupling. The competition between ferromagnetic and antiferromagnetic Fe-Fe and Fe-Mn interactions and the local magnetovolume instability near carbon may give rise to the spin-glass-like regions observed in austenitic Fe-Mn-C alloys.

Comparative susceptibility of indigenous and improved pig breeds to Classical swine fever virus infection: practical and epidemiological implications in a subsistence-based, developing country setting

This study investigated the comparative susceptibility of indigenous Moo Laat and improved Large White/Landrace pig breeds to infection with classical swine fever virus (CSFV) under controlled conditions in the Lao People's Democratic Republic (Lao PDR). The Moo Laat (ML) and Large White/Landrace cross-breed (LWC) pigs were inoculated with a standard challenge strain designated Lao/Kham225 (infectivity titre of 10(2.75) TCID50/ml). The results demonstrated that both the native breed and an improved pig breed are fully susceptible to CSFV infection and the mortality rate is high. LWC pigs demonstrated lower (or shorter) survival times (50% survival time: 11 days), earlier and higher pyrexia and earlier onset of viraemia compared to ML pigs (50% survival time: 18 days). In the context of village-based pig production, the longer time from infection to death in native ML pigs means that incubating or early sick pigs are likely to be sold once an outbreak of CSF is recognized in a village. This increased longevity probably contributes to the maintenance and spread of disease in a population where generally the contact rate is low.

Comparative study of strongyle infections of cattle and buffaloes in Mindanao, the Philippines

Faecal samples were collected from 500 cattle and 385 buffaloes belonging to backyard farmers from 24 villages in the province of Bukidnon, Mindanao, the Philippines. Strongyle nematode infections were studied on these samples by faecal egg counts and infective larvae differentiation. The effects of animal species and age on the prevalence and intensity of infections were studied. The overall prevalence of strongyle infection was 53% for cattle and 28% for buffaloes. The prevalence decreased with increasing age in both animal species. Faecal egg counts were significantly lower in buffaloes than in cattle. Adult animals had lower egg counts than calves. This age effect was most pronounced in buffaloes. Six genera of strongyle nematodes were identified from the faecal cultures in both animal species, Mecistocirrus, Haemonchus, Trichostrongylus, Cooperia, Bunostomum and Oesophagostomum. The distribution of larvae did not vary much with age.

Development of immunity to Mecistocirrus digitatus (Nematoda: Trichostrongylidae) in calves

The importance of the third (L3), fourth (L4) and adult stages of Mecistocirrus digitatus in inducing resistance to reinfection was examined. Three groups of 5 calves (A, B, C) were immunized for 2 consecutive days with a daily dose of 20,000 M. digitatus infectious larvae. Group A was treated with ivermectin 7 days post-infection (exposed to L3), group B was treated after 26 days (exposed to L3 and L4) and group C after 60 days (exposed to L3, L4 and adults). Thirty days posttreatment, animals were challenged with 30,000 M. digitatus L3. Five previously uninfected control animals (group D) also received 30,000 L3. All animals were necropsied 75 days post-challenge. Increases in exposure to the immunizing infection resulted in significant increases in the pre-patent period post-challenge; 54 days in the controls, compared with 63, 70 and 72 days for groups A, B and C, respectively. Only adult worms were recovered at necropsy, and the mean number of worms significantly increased with increasing exposure to the immunizing infection: 355 in the controls, compared to 481, 937 and 1174 in groups A, B and C, respectively. No significant changes in worm length were observed. Infection with M. digitatus significantly affects a subsequent challenge infection--stimulation of the immune system by exposure to L3 extends the pre-patent period, and suppression by later stages (L4, adult) leads to higher worm burdens.

Epidemiology of Mecistocirrus digitatus and other gastrointestinal nematode infections in cattle in Mindanao, Philippines

Over a period of 14 months, faecal and serum samples were collected monthly from cattle of 1 to 30 months old on three ranches (20-25 animals ranch-1 sample-1) in Mindanao, Philippines. Individual faecal egg counts, serum pepsinogen levels and Mecistocirrus digitatus specific antibodies were determined, and infective larvae from pooled faecal samples were examined. Post mortem worm counts were carried out on tracer calves (n = 16) that had been kept for 30 days with the herds on two of the ranches. A number of gastrointestinal nematode species were present: M. digitatus, Haemonchus placei, H. similis, Trichostrongylus axei, Cooperia punctata, C. pectinata, Bunostomum phlebotomum and Oesophagostomum radiatum. Strongyle eggs first appeared in the faeces of calves of two months old, egg counts peaked when animals were 3-6 months old, after which they steadily and significantly declined. Faecal egg output of M. digitatus increased up to the age of 10 months, after which there was a steady but not significant decline until the age of 24 months. In faecal cultures the relative proportion of Cooperia larvae decreased from over 70% in 0-6 month old animals to 30% in 19-24 month old animals, and a corresponding 30% increase in the proportion of Mecistocirrus was observed. Both serum pepsinogen and M. digitatus specific antibodies levels increased during the first year of life, and then remained at the same level in older animals. Whereas the total faecal egg output did not significantly vary throughout the year, worm counts from tracer calves indicated a marked seasonality in transmission.

Pathophysiological aspects of Mecistocirrus digitatus (Nematoda: Trichostrongylidae) infection in calves

Three groups of four calves were experimentally infected with infectious larvae of Mecistocirrus digitatus. One group received a trickle infection of 5000 L3 per day for 8 days, the other two groups received a single infection of 5000 and 40,000 L3, respectively. All animals were necropsied 120 days after infection. Prepatent periods varied between 61 and 79 days, and maximal faecal egg output was reached between 80 and 100 days after infection. Repeated infections were not additive and worm counts at 120 days after infection varied between 100 and 440 in the first two groups and between 120 and 1700 in the last group. There was no significant difference in worm counts between the different infection regimes. However, there was a significant positive relationship between worm burden and faecal egg counts. In addition, there were significant negative relationships between worm burden and packed cell volume, and weight gain. The relative decreases in packed cell volume and weight gain emerged 70-80 days after infection. Serum pepsinogen levels were significantly elevated by the end of the trial, but the observed positive relationship between worm burden and pepsinogen was not significant. An enzyme immunoassay based on crude adult antigen was able to detect M. digitatus infection at 90 and 100 days after infection, but again there was no significant association between worm burden and antibody levels. Therefore, anaemia and a reduction in weight gain caused by the haematophagous activity of adult stages seem to be the most important pathogenic effects of M. digitatus infection in calves.

Thelazia rhodesii (Desmarest, 1828) infections in cattle in Mindanao, Philippines

Thelazia rhodesii was found in the eyes of 149 of 643 bovine heads (23%) that were examined at the abattoir of Cagayan de Oro City, Philippines, during the period February 1994 to February 1995. In nearly half of the animals both eyes were infected and an average of 4.1 worms per infected animal was recovered. Of the 1286 eyes examined, 17% were infected; worm burdens ranged from one to 36 (average 2.9) worms per infected eye. Monthly prevalence of infection ranged from 13% to 36%. T. rhodesii infection was significantly more common in cattle of more than 3 years of age (25%) than in younger animals (15%). Ocular lesions were observed in 73 (11%) cattle; 22% of these were infected with T. rhodesii. There was no relationship between presence of T. rhodesii and ocular lesions.

Mammomonogamus laryngeus (Railliet, 1899) infections in cattle in Mindanao, Philippines

During one year, 597 cattle were examined for Mammomonogamus laryngeus infections in the abattoir of Cagayan de Oro, Philippines. The overall prevalence was 23% with no obvious seasonal variations. The infection rate was 19% in animals up to 4 years old and 24% in animals 4-12 years old. In infected animals up to 8 years old an average of eight parasite pairs was found; infected animals of 8-12 years old had 5.2 parasite pairs on average. All worms were located on the posterior side of the epiglottis. Field observations on cattle in Mindanao revealed that adult M. laryngeus had developed on the epiglottis of a tracer calf that had been on pasture for 30 days and then kept away from possible nematode infection for 28 days.

The epidemiology of Schistosoma spindale Montgomery, 1906 in cattle in Sri Lanka

During 1988 and 1989, the mesenteric veins of 901 cattle were examined for the presence of schistosomes at the Kandy slaughterhouse (Sri Lanka). The overall prevalence of infection was 31.2%. Animals younger than 2 years were less infected (21.3%) than those older than 5 years (47.9%). Based on the number of paired worms counted, three intensities of infection were recognized: low (1-20 pairs), moderate (21-100 pairs) and heavy (greater than 100 pairs). Intensities increased with the age of the animals but remained low (average 10 worm pairs). The worm burden increased by approximately 20% for each step in age group. The number of miracidia/100 g faeces was measured in 85 animals of all age groups and intensities of infection; 77% of the samples contained less than 100 miracidia. Miracidia counts decreased with age; moderately and heavily infected animals in each age group had the highest and the lowest counts, respectively. This may be due to a host immune response. The results raise questions on the sensitivity of faecal egg counts as a diagnostic method for visceral schistosomiasis in cattle.

Studies of the relationships between Schistosoma nasale and S. spindale and their snail host Indoplanorbis exustus

Infectivity and cercarial production of Indoplanorbis exustus related to variation of miracidial dose (1, 4, 10 or 20) with Schistosoma nasale and S. spindale from Sri Lanka were studied. The intermediate host-parasite relationships of the two schistosome species showed marked differences under the conditions of observation recorded in this study. Prepatent death rates (PDR) were on average higher for S. spindale (30%) than for S. nasale (10%). The size of the miracidial dose to which snails had been exposed had no effect on PDR. The infection rates (IR) were on average higher for S. nasale (41%) compared with S. spindale (27%). Highest IR occurred after exposure to 4 miracidia in S. nasale infections (79%) and after exposure to 10 miracidia in S. spindale infections (60%). The highest daily average cercarial production per snail was recorded for S. nasale at a level of 4 miracidia (1311), and for S. spindale at a level of 10 miracidia (1615). At low level (1 or 4 miracidia) of exposure, I. exustus showed a better compatibility with S. nasale than with S. spindale. An opposite tendency was observed at higher levels (10 or 20 miracidia) of exposure. Unsuccessful infections of Lymnaea luteola with either S. nasale or S. spindale indicate that this species is not involved in transmission.

Gastro-intestinal nematode infections in a goat breeding farm in north-western Sri Lanka

Faecal egg counts were used to study patterns of nematode infestation of adult female goats and their offspring according to season, pregnancy and lactation or age on a goat farm (n = 2000) in north-western Sri Lanka. Average rainfall in the area is 825 mm and temperature is between 23 and 33 degrees C throughout the year. The only nematode species present on the farm were Haemonchus contortus and Oesophagostomum columbianum. In adult females the faecal egg output was not influenced by season and no significant periparturient rise was observed. In kids the egg counts rose from the third month of age onwards and reached the same levels as the adults by the fourth month. Post-mortem studies on a neighbouring farm indicated that hypobiosis was not present.

Pathology of natural infections of Schistosoma spindale Montgomery, 1906, in cattle

The pathology of natural Schistosoma spindale infections in cattle in Sri Lanka was studied. Hepatic lesions were moderate with periportal cell infiltration and periportal epithelioid cell granulomas within perilobular zones. Submucosal and mucosal granulomas accompanied by cellular changes were present in the small and large intestine. Two unusual observations included the migration of an adult worm from the mesenteric veins to the mucosa of the small intestine in one bull and the presence of epithelioid cell granulomas containing slender living eggs in the urinary bladder of one animal. Intensities of infections, histopathological changes and immunological responses are discussed and comparison is made with other schistosome species.

The prevalence and pathology of Schistosoma nasale Rao, 1933 in cattle in Sri Lanka

During 1987 a total of 1393 cattle was examined for Schistosoma nasale infection at the Kandy slaughterhouse, Sri Lanka. The overall prevalence was 12.6% (monthly range 3-17%). Based on the appearance of macroscopic lesions, 6 types (0-5) were recognized; type 5 being the most severe, with cauliflower-like growths obstructing the nasal cavity. Older bovines with 8 permanent incisors were more heavily infected (29.1%) than younger ones with no permanent incisors (6.0%). The severity of the lesions increased also with the age of the animals. Observations on the localization of the lesions showed that the first sessile nodular areas appear on the medial septum, on the dorsal edge of the ventral nasal concha and on the lateral wall of the middle meatus of the nasal cavity. Later, they gradually spread over the whole mucosal surface of the anterior part of the cavity but were rarely found further than 10 cm posterior to the nasal opening. The histopathology showed that granuloma formation due to the presence of eggs was the most common feature of the respiratory mucosa.

Mammomonogamus laryngeus (Railliet, 1899) infections in cattle from Sri Lanka

During one year 1249 male cattle were examined for Mammomonogamus laryngeus infections in the slaughterhouse at Kandy, Sri Lanka. The overall prevalence was 40% with only light monthly variations (34 to 52%). The infection rate was highest (47%) in 2 to 2.5 year old animals. In infected animals an average of 6.4 parasite pairs was found with higher numbers in older animals. The majority of worms were located on the posterior side of the epiglottis. Lesions observed were mucosal plugs at the site where the parasites were attached to the mucosa and moderate to severe erosions and ulcers in other zones.