Abstract Introduction and objectives Multimodal Analgesia (MMA) has shown promising results in postoperative outcomes across a broad spectrum of surgeries, including bariatric surgery. We compared the analgesic effect immediately after Laparoscopic Bariatric Surgery (LBS) of the combined effect of MMA and methadone against two techniques that were based mainly on the use of high-potency medium-acting opioids. Methods Two hundred seventy-one patients were retrospectively reviewed. The primary outcome was postoperative pain score > 3/10 measured by the Verbal Numeric Scale (VNS) during the Postanesthetic Care Unit (PACU) stay. The three protocols of intraoperative analgesia were: (P1) sufentanil at anesthetic induction followed by remifentanil infusion; (P2) sufentanil at induction followed by dexmedetomidine infusion; and (P3) remifentanil at induction followed by MMA including dexmedetomidine, magnesium, lidocaine, and methadone. Only P1 and P2 patients received morphine toward the end of surgery. Poisson regression was used to adjust confounding factors and calculate Prevalence Ratio (PR). Results Postoperative VNS > 3 was recorded in 135 (49.81%) patients, of which 93 (68.89%) were subjected to P1, 25 (18.56%) to P2, and 17 (12.59%) to P3. In the final adjusted model, both anesthetic techniques (P3) (PR = 0.10; 95% CI [0.03-0.28]), and (P2) (PR = 0.42%; 95% CI [0.20-0.90]) were associated with lower occurrence of VNS > 3, whereas age range 20-29 was associated to higher occurrence of VNS > 3 (PR = 3.21; 95% CI [1.22-8.44]) in PACU. Postoperative Nausea and Vomiting (PONV) was distributed as follows: (P1) 20.3%, (P2) 31.25% and (P3) 6.77%; (P3 < P1, P2; p< 0.05). Intraoperative hypotension occurred more often in P3 (39%) compared to P2 (20.31%) and P1 (17.46%) (p< 0.05). Conclusion MMA + methadone was associated with higher incidence of intraoperative hypotension and lower incidence of moderate/severe pain in PACU after LBS.

RESUMO JUSTIFICATIVA E OBJETIVOS: O objetivo deste estudo foi comparar técnicas anestésicas com sufentanil em diferentes doses na indução anestésica e infusão contínua de remifentanil ou dex medetomidina no intraoperatório para manutenção da anestesia, relacionando tais fatores à incidência de dor, náuseas e vômitos no pós-operatório e demais complicações na sala de recuperação pós-anestésica. MÉTODOS: Estudo observacional analítico retrospectivo reali zado em pacientes obesos (n=120). Os pacientes incluídos foram selecionados aleatoriamente e constituíram 4 grupos de 30 pa cientes cada: G1 - indução com sufentanil 0,5 µg.kg-1 associado à infusão continua de remifentanil; G2 - indução com sufentanil 0,7 µg.kg-1 associado à infusão contínua de remifentanil; G3 - indução com sufentanil 0,5 µg.kg-1 associado à infusão contínua de dexmedetomidina; G4 - indução com sufentanil 0,7 µg.kg-1 associado à infusão contínua de dexmedetomidina. Considerou -se como critério de significância valor de p<0,05. RESULTADOS: A incidência de dor na sala de recuperação pós -anestésica foi de 52,5% (n=63) e, entre esses, em 36,11% dos casos foi considerada intensa. A incidência de dor foi menor nos pacientes que receberam infusão de dexmedetomidina compara do àqueles que receberam infusão de remifentanil. A dose de su fentanil na indução anestésica não influenciou na incidência de dor (G1=G2>G3=G4) (p<0,05). A ocorrência de complicações respiratórias não apresentou diferença estatisticamente significa tiva entre os grupos. CONCLUSÃO: O uso de dexmedetomidina apresentou vanta gem em relação à analgesia na sala de recuperação pós-anestésica, sem aumento no risco de complicações respiratórias, quando comparado à infusão contínua de remifentanil, independente mente da dose de sulfentanil utilizada na indução.

ABSTRACT BACKGROUND AND OBJECTIVES: Compare anesthesia techniques with sufentanil and intraoperative infusion of remifentanil or dexmedetomidine, and to then analyze their associations with the incidence of pain and other complications in the post-anesthesia care unit. METHODS: A retrospective analytical observational study conducted in a reference center for bariatric surgery in São Paulo, São Paulo State, Brazil. Patients (n=120) included in the study were randomly selected using this site’s anesthesia records for bariatric surgery. Four 30-patient groups were established: G1 - induction with 0.5 µg.kg-1 sufentanil associated with the continuous infusion of remifentanil; G2 - induction with 0.7 µg.kg-1 sufentanil associated with the continuous infusion of remifentanil; G3 - induction with 0.5 µg.kg-1 sufentanil associated with the continuous infusion of dexmedetomidine; and G4 - induction with 0.7 µg.kg-1 sufentanil associated with the continuous infusion of dexmedetomidine. Significance was set at p<0.05. RESULTS: The incidence of pain in the post-anesthesia care unit was 52.5% (n=63). It was considered intense in 36.11% of these cases. The incidence of pain in the post-anesthesia care unit was lower in patients receiving a continuous infusion of dexmedetomidine relative to those who received remifentanil infusion. Sufentanil dosage in anesthesia induction did not influence the incidence of pain (G1=G2>G3=G4; p<0.05). The occurrence of respiratory complications did not differ significantly between the groups. CONCLUSION: The use of dexmedetomidine proved to be better for analgesia in the post-anesthesia care unit, and it did not increase the risk of respiratory complications when compared to the continuous infusion of remifentanil, regardless of the sufentanil dose used for induction.

JUSTIFICATIVA E OBJETIVOS: A dor pós-operatória em pacientes obesos é um evento prejudicial para sua recuperação, retardando a alta e aumentando a chance de complicações. O objetivo deste estudo foi determinar a frequência de dor na sala de recuperação pós-anestésica e averiguar os fatores associados à ocorrência de dor moderada ou intensa em obesos submetidos a gastroplastia, relacionando-os a possíveis complicações. MÉTODOS: Estudo observacional prospectivo incluindo 84 pacientes submetidos a anestesia geral com sevoflurano para gastroplastia laparoscópica. Na sala de recuperação pós-anestésica, os pacientes foram avaliados quanto à intensidade da dor pela escala numérica e verbal, sedação (escala de Ramsay), ocorrência de náuseas, vômitos e complicações respiratórias. O modelo de regressão logística foi utilizado para determinar as variáveis independentes associadas à dor. RESULTADOS: Na sala de recuperação pós-anestésica, a ausência de dor na admissão ocorreu em 61,63% dos pacientes. Na análise multivariada, o uso do opioide fentanil em comparação ao sufentanil foi o único fator independentemente associado à dor (RR 3,07 - IC95% 1,17-6,4). Não houve diferença entre o tipo de opioide utilizado e a ocorrência de náuseas e vômitos (p>0,05). Os escores da escala de Ramsay não diferiram entre os tipos de opioides utilizados no intraoperatório (p>0,05). CONCLUSÃO: O único fator independentemente associado à dor na sala de recuperação pós-anestésica foi o tipo de opioide utilizado na indução anestésica. A dor pós-operatória ainda é um evento frequente que acomete a maioria dos pacientes e protocolos de analgesia precisam ser implementados para minimizar os efeitos que a dor subtratada pode causar.

BACKGROUND AND OBJECTIVES: Postoperative pain in obese patients is a noxious event for their recovery delaying hospital discharge and increasing the chance of complications. This study aimed at determining pain frequency in the post-anesthetic care unit and at investigating factors associated to moderate to severe pain in obese patients submitted to gastroplasty, relating them to potential complications. METHODS: This is an observational and prospective study including 84 patients submitted to general anesthesia with sevoflurane for laparoscopic gastroplasty. Patients were evaluated in the post-anesthetic care unit for pain intensity by the verbal and numerical scale (Ramsay scale), presence of nausea, vomiting and respiratory complications. Logistic regression model was used to determine pain-related independent variables. RESULTS: There has been no pain at admission to the post-anesthetic care unit in 61.63% of patients. In the multivariate analysis, fentanyl as compared to sufentanil was the only independent factor associated to pain (OR 3.07 - IC95% 1.17 - 6.4). There has been no difference between the type of opioid used and the presence of nausea and vomiting (p>0.05). Ramsay scale scores were not different between opioids used in the intraoperative period (p>0.05). CONCLUSION: The only independent factor associated to pain in the post-anesthetic care unit was the type of opioid used for anesthetic induction. Postoperative pain is still a frequent event affecting most patients, and analgesic protocols have to be implemented to minimize the effects that undertreated pain may induce.