Erector spinae plane block for chronic low back pain analgesia: A case series

BACKGROUND

Chronic low back pain (CLBP) is a frequent condition, poorly managed with conventional treatments. The ultrasound-guided erector spinae plane block has increasingly been used in the management of acute and chronic pain. We aimed to determine this technique's analgesic efficacy in patients with moderate to severe CLBP.

METHODS

Ten consecutively selected patients: adults, regularly followed in our Pain Clinic with moderate/severe long-term CLBP refractory to pharmacological treatment, VAS > 4. Prospective data collection: before the intervention -demographical data, past medical history, current pain therapies, VAS pain level, Brief Pain Inventory- Short Form and Neuropathic Pain Questionnaire; 30 min after - VAS and satisfaction level; 24 and 72 h, 7 days and 1 month after - complications and pain level.

RESULTS

Majority of females (90%), mean age of 70.3 years-old. All had primary musculoskeletal CLBP. 90% experienced severe pain (VAS >= 7) in the last 24 h. Half presented neuropathic characteristics. Patients were very satisfied with the technique (mean: 8.75) with immediate pain relief (VAS mean: 2.3). 24 and 72 h, 7 days and 1 month after the treatment VAS means were 3.2, 3.1, 3.8 and 6.2. We report a 20.8 days duration mean. No short or long-term complications.

DISCUSSION AND CONCLUSIONS

Ultrasound-guided erector spinae plane block has preliminary advantages in CLBP: easily performed with low complications risk, immediate discharge home with absence of motor block, 100% efficacy at short and medium-terms. Even though pain's relief was shorter than a month, it is a useful tool allowing patients' well-being, physical rehabilitation and exercise during this period.

Early resynchronization of non-pregnant beef cows based in corpus luteum blood flow evaluation 21 days after Timed-AI

The study aimed to verify whether a hormone protocol started at Day 13 (D13) after Timed Artificial Insemination (TAI) influences the conception rate. Nelore cows (primiparous and multiparous) from two commercial beef farms (n = 1,431) were first TAI (D0). Timed AI was performed in lots (TAI Lots) ranging from 187 to 346 cows. On D13, regarding the TAI lot, cows were assigned for either receiving (Resynch group, n = 1,002) or not (Control group, a subset of approximately 30%, n = 429) another hormone protocol for resynchronization. The same hormone protocol was used for the first TAI and for the resynchronization, except for 1 mg instead of 2 mg of estradiol benzoate (EB) at the begging of the protocol. Eight days later (D21), the Resynch group was checked for corpus luteum blood flow by color Doppler ultrasonography, and in those detected as non-pregnant, the protocol was completed and a 2nd TAI was performed at D23. Pregnancy diagnosis was later (D30) performed by B-mode ultrasonography in the control group and confirmed in the presumptive pregnant cows from the 1st TAI of the Resynch group. The remaining cows were checked for pregnancy 30 days after the 2nd TAI (experimental Day 53). The statistical model to explain conception rate considered the effects of Group (Control or Resynch), Farm, Parity (primiparous or multiparous), Sire, Technician (who perform AI), TAI Lot and pertinent interactions (Group*Parity, Group*Farm and Group*TAI Lot). The statistical analyses of the model were performed using the Proc Glimmix (SAS virtual University Edition). The conception rate for the 1st TAI was similar (P > 0.4) between Control (50.3%, 216/429) and Resynch group (52.6%, 527/1002). The positive predictive diagnostic on D21 showed high relation with PD30 (90.7%, 527/581). In Resynch group, non-pregnant cows (n = 421, 1002 minus 581) were re-inseminated. The conception rate of the 2nd TAI (42.8%, 180/421) was affected (P < 0.002) by side effects of the Farm (48.5 vs. 33.1%) and Parity (51.2 vs. 40.3%, for multiparous vs. primiparous, p < 0.001). Nevertheless, after the 2 TAIs of the Resynch group, the cumulative conception rate was 70.5% (707/1002). In conclusion, the early resynchronization of cows with a low (1 mg) EB dose and progesterone device at D13 after TAI can be used as a strategy to reduce conception interval in beef cattle, and thus to increase the number of pregnant cows from artificial insemination after the breeding season.

Spiroplasma infection in Drosophila melanogaster: what is the advantage of killing males?

Male-killing bacteria are maternally inherited agents that cause death of sons of infected females. Their transmission rate is commonly high but imperfect and also sensitive to different environmental factors. Therefore, the proportion of infected females should be reduced in each generation. In order to explain male-killers spread and persistence in host population, a mechanism resulting in the relative increase of infected females must outweigh the losses caused by the imperfect transmission. The resource release hypothesis states that the males' death results in increased resources available to sibling females which would otherwise be used by their male siblings. Infected females are then expected: to be larger than uninfected females in natural populations; or to have higher viability; or to have shorter development times; or any combination of these outcomes. Here, we tested the resource release hypothesis by measuring body size of infected and uninfected wild-caught Drosophila melanogaster females and carried out other fitness related measures in the laboratory. Wild-caught infected females produced more daughters than uninfected females in their first days in the laboratory. However, although no significant difference in viability was found in a controlled experiment with infected and uninfected flies from a standard laboratory strain, there was a decrease in development time probably mediated by reduced competition. Fitness effects conditioned by the host genetic background are pointed out as a possible explanation for this difference between wild and laboratory flies. Our findings are discussed in the context of the resource advantage hypothesis.

[Limb amputations carried out in hospitals of the national health service in the years from 1990 to 1993]

This study was to assess the number of limbs amputations in Portugal State Hospitals over a four years period (1990 to 1993), analysing their incidence according to etiology, sex, average age, duration of hospitalization, level of amputation and mortality rate. The authors emphasise the levels of amputation which are mot favourable for an effective rehabilitation.