Perioperative evaluation of tumescent anaesthesia technique in bitches submitted to unilateral mastectomy

Abstract

BackgroundTumescent anaesthesia (TA) is a widely used technique in oncologic surgeries necessitating large resection margins. This technique produces transoperative and postoperative analgesia, reduces surgical bleeding, and facilitates tissue divulsion. This prospective, randomised, blind study evaluated the use of TA in bitches submitted to mastectomy and compared the effect of TA with an intravenous fentanyl bolus. A 2.5-mcg/kg intravenous fentanyl bolus (n = 10) was compared with TA using 0.275% lidocaine (n = 10) in bitches submitted to unilateral mastectomy. Sedation was performed by intramuscular (IM) injection of 0.05 mg/kg of acepromazine combined with 2 mg/kg of meperidine. Anaesthesia was induced with 5 mg/kg of intravenous propofol and maintained with isoflurane/O2. Heart and respiratory rates; systolic, mean, and diastolic arterial blood pressures; central venous pressure; SpO2; ETCO2; inspired and expired isoflurane concentrations; and temperature were measured transoperatively. Visual analogue scales for sedation and pain and the Glasgow composite and Melbourne pain scales were used for postoperative assessment. The surgeon investigated the quality of the surgical approach, considering bleeding and resection ability, and the incidence of postoperative wound complications.ResultsThe heart rate was lower and the end-tidal isoflurane concentration was higher in dogs treated with fentanyl than in dogs treated with TA. A fentanyl bolus was administered to 8 of 10 dogs treated with fentanyl and to none treated with TA. Intraoperative bleeding and the mammary gland excision time were lower in dogs treated with TA. The maximal mean and individual plasma lidocaine concentrations were 1426 ± 502 ng/ml and 2443 ng/ml at 90 minutes after infiltration, respectively. The Glasgow Composite Pain Scale scores were higher in dogs treated with fentanyl than in dogs treated with TA until 2 hours after extubation.ConclusionsCompared with intravenous fentanyl, TA in bitches: may be easily performed in non-inflamed, ulcerated, adhered mammary tumours; has an isoflurane-sparing effect; improves transoperative and immediate postoperative analgesia; is apparently safe for use in clinical conditions as evidenced by the fact that it did not produce any adverse signs or lidocaine plasma concentrations compatible with toxicity; does not modify the recovery time; and facilitates the surgical procedure without interfering with wound healing.

Evaluation of Postoperative Residual Analgesia of Two Solutions Used for Local Anesthesia By Tumescence In Bitches who Underwent a Unilateral Mastectomy

“…Outros autores [3] compararam a técnica de anestesia convencional à anestesia por tumescência e concluíram que nesta última há redução da dor no período pós-operatório; bem como, observou-se que ao comparar a técnica de tumescência com lidocaína à infusão contínua de fentanil, utilizando como MPA a associação de acepromazina e meperidina [5], obtiveram resultados semelhantes aos do estudo aqui apresentado, com uma média de resgate analgésico em 60 min após o final da cirurgia. Neste estudo pode-se afirmar que a analgesia do período pós-operatório se torna mais efetiva quando associada a um protocolo de analgesia preemptiva ou multimodal, observando-se uma melhor qualidade na recuperação no pós-operatório imediato das pacientes por ser um incremento a analgesia local.…”

“…A solução para tumescência no GTL foi composta por 210 mL de Ringer com Lactato 3 previamente refrigerado entre 8 e 12°C, 40 mL de cloridrato de lidocaína 6 2% sem vasoconstritor e 0,5 mL de adrenalina 6 1 mg/mL [10]. Para o GTR foram utilizados 233,3 mL de Ringer com Lactato 3 na mesma temperatura que a solução anterior, 16,7 mL de ropivacaína 5 7,5 mg/mL e 0,5 mL de adrenalina 6 1 mg/mL [2], e utilizados 15 mL/kg de cada solução para infiltração em toda a cadeia mamária a ser retirada.…”

Tumescent anesthesia or epidural anesthesia combined with intercostal block in bitches submitted to mastectomy

“…Thirty minutes after the end of anesthesia, the dog was submitted to the first postoperative pain assessment (T0), using the modified Glasgow pain scale [5]. Four additional evaluations were performed: the first two with an hour interval between each (T1, T2) and the last two with a two-hour interval between each (T4, T6), totaling to 6 hours.…”

“…Locoregional anesthesia is an element of multimodal pain management and is widely used in veterinary medicine because it reduces the operative use of general anesthetics and analgesics. Tumescent local anesthesia (TLA) is the most commonly used approach in dogs undergoing mastectomy and involves the administration of large amounts of diluted anesthetic solution in the subcutaneous tissue capable of promoting transand postoperative analgesia (5) . However, there are limitations to its use, as in the case of poorly defined tumors, skin infection, or ulcerated tumors, owing to the risk of postoperative infection or seeding of neoplastic cells (6) .…”

“…Não houve diferenças entre os parâmetros clínicos (p > 0,05) no período transoperatório entre e dentro dos grupos. O GEBI apresentou maior quantidade de resgates analgésicos transoperatórios (9) em relação a GALT (5), porém sem diferenças estatísticas. No pós-operatório, nenhum animal de ambos os grupos atingiu pontuação máxima para resgate analgésico.…”