Constant Rate Infusion of Lidocaine, Tumescent Anesthesia and Their Combination in Dogs Undergoing Unilateral Mastectomy

Tumescent anesthesia (TUM) is a technique that was initially used to perform liposuction under local anesthesia, which consists of the injection of such large volumes of local anesthetic until to produce swelling and firmness (tumescence) of the surgical area. The aim of this study was to compare the intraoperative analgesic efficacy of lidocaine (LID) constant rate infusion (CRI), of TUM, or their combination (LID/TUM) and the postoperative pain and analgesic requirement in dogs undergoing unilateral mastectomy. Twenty-four dogs were premedicated with dexmedetomidine (3 μg/kg) and methadone (0.2 mg/kg) intravenously (IV). After induction with propofol IV to effect, dogs were randomly allocated to receive a loading dose of lidocaine (2 mg/kg) followed by a CRI of 100 μg/kg/min (Group LID) in addition to an equivalent volume of lactated Ringer’s solution instead of local TUM; a loading dose of lactated Ringer’s solution followed by a CRI of Ringer’s solution in addition to TUM (Group TUM); a loading dose of lidocaine (2 mg/kg) followed by a CRI of 100 μg/kg/min in addition to TUM (Group LID/TUM). Anesthesia was maintained with isoflurane in oxygen. Postoperative pain scores were assessed once the dogs had fully recovered from the sedative effects, and following 15, 30, 45 and 60 min. The results of the current study allow us to assert that all three treatments provided satisfactory intraoperative antinociceptive effects but administration of LID/TUM induced greater inhibition on sympathetic stimulating effect up to 60 min from recovery, thus, providing better early postoperative pain relief in dogs undergoing mastectomy.

Veterinary approaches to canine mammary tumors and knowledge of the consensus statement in Brazil

Mammary gland tumors are one of the most commonly diagnosed tumors in female dogs, with a reported prevalence ranging from 26 to 73% in Brazil. In recognition of the importance of these tumors veterinary researchers and clinicians in Brazil produced the first consensus statement regarding canine mammary tumors in 2010. The intention was to establish criteria for diagnosis, prognosis, and treatment. This study evaluated the methods of prevention, diagnosis, treatment, and determination of prognosis used by veterinarians in Brazil, and sought to quantify the number of veterinarians who were aware of the consensus statement. One hundred and three veterinary clinics participated in the study, 87.37% of which recommend early neutering as a preventative treatment for mammary tumors. For diagnosis, 100% of these use laboratory testing, 94.17% perform chest radiography, 78.64% incisional biopsies, 44.66% cytological analysis, and 13.59% immunohistochemical analysis. The most common surgical procedure is unilateral mastectomy (72.81%), and chemotherapy is performed in 49.51% of the clinics. Of the 103 clinics, 66.01% were aware of the consensus. Although knowledge of the consensus statement is widespread among veterinarians in Brazil, not all its recommendations are being followed. Preventive actions for canine mammary tumors are well established in most parts of the country. However, the consensus statement has had little influence on informing prognostic and therapeutic approaches, with a poor uptake of surgical removal of lymph nodes and immunohistochemical examination.

Use of Spinal Anaesthesia with Anaesthetic Block of Intercostal Nerves Compared to a Continuous Infusion of Sufentanyl to Improve Analgesia in Cats Undergoing Unilateral Mastectomy

Unilateral mastectomy is a common surgical procedure in feline species and requires postoperative pain management. Our study aimed to evaluate the analgesic efficacy of subarachnoid anaesthesia combined with an intercostal nerve block, in comparison with the use of sufentanyl citrate administered as a constant-rate infusion (CRI). Twenty cats were randomly divided into two groups (n = 10/group) based on the analgesic protocol used: the first received loco-regional anaesthesia with levobupivacaine (LR group), and the second received a CRI of sufentanyl (SUF group). The evaluation criteria during surgery were the need for a bolus of fentanyl in the event of an increased heart rate or increased blood pressure. In the postoperative period, the levels of comfort/discomfort and pain were used to obtain a score according to the UNESP-Botucatu multimodal scale. Subjects who scored above seven received analgesic drug supplementation. Intraoperative analgesia was satisfactory, with good haemodynamic stability in both groups. Four patients in the LR group required an extra dose of methadone after they achieved the sternal decubitus position, whereas those in the SUF group required many more doses. The analgesia achieved in the LR group was more satisfactory than that in the SUF group.

Trends in bilateral mastectomy for cases of unilateral breast cancer in a Brazilian institute over a 10-year period

Introduction: There has been a substantial increase worldwide in the number of women with unilateral breast cancer who undergo bilateral mastectomy. Possible contributing factors include the advent of nipple-sparing mastectomy (NSM) and an improvement in breast reconstruction techniques. This study evaluated the trend in bilateral mastectomy at the Ceará Cancer Institute in Brazil. Methods: Patients with unilateral breast cancer who underwent mastectomy and immediate breast reconstruction were evaluated retrospectively between 2009 and 2018. Clinical, pathological and surgical factors were analyzed to determine their possible effects on the type of surgery performed. Results: Of 121 patients, 77 (63.6%) were submitted to unilateral mastectomy, while 44 (36.4%) underwent bilateral mastectomy. Most were treated with NSM (n = 66; 54.5%), with this technique being significantly associated with bilateral mastectomy (p < 0.001). Bilateral mastectomy increased significantly over the period (p = 0.009; r2 = 0.592), but unilateral mastectomy did not (p = 0.417; r2 = 0.084). Age < 45 years (p = 0.007) and negative axilla (p = 0.003) were also associated with bilateral mastectomy, while axillary dissection was associated with unilateral mastectomy (p = 0.028). Multivariate analysis showed the 2016-2018 period to be an independent factor associated with bilateral mastectomy. Conclusions: These results corroborate the international literature. From 2010 onwards, there was a trend towards an increase in bilateral mastectomy with breast reconstruction. These data may contribute to multidisciplinary debates, facilitating the establishment of guidelines. Further studies are required to improve understanding of this phenomenon in Brazil.