Abstract Background Breast cancer surgery is associated with considerable acute post-surgical pain and restricted mobility. Various regional and neuraxial anesthesia techniques have been used to alleviate post-mastectomy pain. Ultrasound-guided serratus anterior plane block (SAPB) has been considered a simple and safe technique. This randomized control study was performed to compare the efficacy of SAPB with the thoracic paravertebral block (TPVB) for postoperative analgesia after breast cancer surgery. Methods A total of 40 adult ASA physical status I - II female patients undergoing radical mastectomy were randomly allocated into two groups to receive either ultrasound-guided TPVB or SAPB with 0.4 mL.kg-1 0.5% ropivacaine, 30 min before surgery. All patients received standardized general anesthesia for surgery. Injection diclofenac and tramadol were used for postoperative rescue analgesia. The time to first rescue analgesia, total analgesic consumption in the first 24 hours, postoperative pain scores, and any adverse effects were recorded. Results The time to first rescue analgesia was significantly longer in the SAPB group (255.3 ± 47.8 min) as compared with the TPVB group (146.8 ± 30.4 min) (p< 0.001). Total diclofenac consumption in 24 hours was also less in the SAPB group (138.8 ± 44.0 mg vs 210.0 ± 39.2 mg in SAPB and TPVB group respectively, p< 0.001). Postoperative pain scores were significantly lower in the SAPB group as compared with TPVB group (p< 0.05). The incidence of PONV was also less in the SAPB group (p= 0.028). No block-related adverse effects were reported. Conclusion We found that the serratus anterior plane block was more effective than the thoracic paravertebral block for postoperative analgesia after breast cancer surgery.

Resumo Justificativa e objetivos: O alívio inadequado da dor após a reconstrução do ligamento cruzado anterior afeta a mobilidade, leva ao desenvolvimento de aderências, inserção do ligamento enfraquecido e atrofia muscular. O bloqueio do canal adutor para analgesia pós-operatória preserva a força do quadríceps. O presente estudo foi feito para comparar o período sem dor em pacientes de reconstrução artroscópica do ligamento cruzado anterior, submetidos ao bloqueio do canal adutor guiado por ultrassom com ropivacaína isolada e ropivacaína + clonidina. Métodos: Um estudo prospectivo, randômico e duplo-cego foi conduzido com 63 pacientes adultos, estado físico ASA I-II, submetidos à reconstrução do ligamento cruzado anterior. Os pacientes foram randomizados em três grupos: Grupo S, que recebeu bloqueio do canal adutor com 30 mL de solução salina para controle; Grupo R, que recebeu bloqueio do canal adutor com 30 mL de ropivacaína a 0,375%; Grupo RC, que recebeu bloqueio do canal adutor com 30 mL de ropivacaína a 0,375% e 1 µg.kg-1 de clonidina. O desfecho primário do estudo foi comparar o período sem dor nos pacientes que receberam bloqueio do canal adutor com ropivacaína isolada ou ropivacina + clonidina. Os desfechos secundários foram escores de dor em repouso e movimento, necessidade total de analgésicos, escore de sedação, além de náusea e vômito no pós-operatório. Resultados: Os períodos médios sem dor foram 20 min, 384,76 min e 558,09 min para os grupos S, R e RC, respectivamente, e essa diferença foi estatisticamente significativa (p < 0,001). Não houve diferença significativa entre os grupos R e RC em termos de escores de dor em repouso e movimento e a necessidade total de analgésicos. Conclusão: A adição de clonidina à ropivacaína em bloqueio do canal adutor guiado por ultrassom levou a um prolongamento significativo do período sem dor, embora os escores de dor em repouso e movimento, e a necessidade de analgésico de resgate, não tenham diferido.

Abstract Background and objectives: Inadequate pain relief after anterior cruciate ligament reconstruction affects mobility leading to development of adhesions, weakened ligament insertion and muscle atrophy. Adductor canal block for postoperative analgesia preserves quadriceps strength. The present study was conducted to compare pain free period in patients undergoing arthroscopic anterior cruciate ligament reconstruction, receiving ultrasound-guided adductor canal block with ropivacaine alone and ropivacaine with clonidine. Methods: A prospective randomized double blinded study was conducted including sixty-three adult, ASA class I, II patients undergoing anterior cruciate ligament reconstruction. They were randomized into three groups: Group S - control group received adductor canal block with 30 mL saline, Group R - ropivacaine group received adductor canal block with 30 mL of 0.375% ropivacaine and Group RC - clonidine group received adductor canal block with 30 mL of 0.375% ropivacaine with clonidine 1 µg.kg-1. The primary aim was to compare the pain free period in patients receiving adductor canal block with ropivacaine alone or ropivacine with clonidine. The secondary outcomes were pain score at rest and movement, total analgesic requirement, sedation score and postoperative nausea and vomiting. Results: The mean pain free periods were 20 min, 384.76 min and 558.09 min for Group S, Group R and Group RC, respectively and this difference was statistically significant (p < 0.001). There was no significant difference between Group R and Group RC in terms of pain scores at rest and movement and total analgesic requirement. Conclusion: Addition of clonidine to ropivacaine in USG guided adductor canal block led to significant prolongation of pain free period though pain score at rest and movement, and rescue analgesic requirement, did not differ.

Resumo Justificativa: A eficácia da pré-oxigenação depende da concentração inspirada de oxigênio, do fluxo de gases, da configuração do circuito respiratório e das características do paciente. Nossa hipótese foi que, no cenário clínico real, no qual o circuito respiratório não é preparado com 100% de oxigênio, os pacientes podem precisar de mais tempo para atingir EtO2 ≥ 90% e essa duração pode ser diferente entre vários circuitos de respiração. Avaliamos, portanto, a eficácia da pré-oxigenação com o uso dos circuitos não preparados Mapleson A, Bain e Circular com volume corrente de respiração com um fluxo de oxigênio de 5 L.min−1 e 10 L.min−1. Métodos: Os pacientes foram alocados aleatoriamente em um dos seis grupos, nos quais foram pré-oxigenados com o uso do circuito Mapleson A, Bain ou Circular com um fluxo de O2 de 5 L.min−1 ou 10 L.min−1. O desfecho primário de nosso estudo foi o tempo necessário para atingir EtO2 ≥ 90% com um fluxo de 5 e 10 L.min−1. Resultados: Com um fluxo de oxigênio de 5 L.min−1, o tempo para atingir EtO2 ≥ 90% foi significativamente maior com o circuito Bain (3,7 ± 0,67 min) do que com os circuitos Mapleson A e Circular (2,9 ± 0,6 e 3,3 ± 0,97 min, respectivamente). No entanto, com o fluxo de oxigênio de 10 L.min−1 foi significativamente menor e comparável entre os três circuitos respiratórios (2,33 ± 0,38 min com Mapleson; 2,59 ± 0,50 min com Bain e 2,60 ± 0,47 min com o Circular). Conclusões: Durante respiração espontânea com volume corrente normal e com um fluxo de oxigênio de 5 L.min−1, o sistema Mapleson A pode pré-oxigenar o paciente de forma ideal dentro de três minutos, enquanto os sistemas Bain e Circular requerem mais tempo. Porém, com um fluxo de O2 de 10 L.min−1, todos os três circuitos respiratórios podem pré-oxigenar o paciente de forma ideal em menos de três minutos.

Abstract Background: Efficacy of preoxygenation depends upon inspired oxygen concentration, its flow rate, breathing system configuration and patient characteristics. We hypothesized that in actual clinical scenario, where breathing circuit is not primed with 100% oxygen, patients may need more time to achieve EtO2 ≥ 90%, and this duration may be different among various breathing systems. We thus studied the efficacy of preoxygenation using unprimed Mapleson A, Bain's and Circle system with tidal volume breathing at oxygen flow rates of 5 L.min−1 and 10 L.min−1. Methods: Patients were randomly allocated into one of the six groups, wherein they were preoxygenated using either Mapleson A, Bain's or Circle system at O2 flow rate of either 5 L.min−1 or 10 L.min−1. The primary outcome measure of our study was the time taken to achieve EtO2 ≥ 90% at 5 and 10 L.min−1 flow rates. Results: At oxygen flow rate of 5 L.min−1, time to reach EtO2 ≥ 90% was significantly longer with Bain's system (3.7 ± 0.67 min) than Mapleson A and Circle system (2.9 ± 0.6, 3.3 ± 0.97 min, respectively). However at oxygen flow rate of 10 L.min−1 this time was significantly shorter and comparable among all the three breathing systems (2.33 ± 0.38 min with Mapleson, 2.59 ± 0.50 min with Bain's and 2.60 ± 0.47 min with Circle system). Conclusions: With spontaneous normal tidal volume breathing at oxygen flow rate of 5 L.min−1, Mapleson A can optimally preoxygenate patients within 3 min while Bain's and Circle system require more time. However at O2 flow rate of 10 L.min−1 all the three breathing systems are capable of optimally preoxygenating the patients in less than 3 min.