Resumo em Inglês:

Abstract Background The underlying mechanism of chronic pain involves the plasticity in synaptic receptors and neurotransmitters. This study aimed to investigate potential roles of Neuroligins (NLs) within the spinal dorsal horn of rats in a newly established Bone Cancer Pain (BCP) model. The objective was to explore the mechanism of neuroligin involved in the occurrence and development of bone cancer pain. Methods Using our rat BCP model, we assessed pain hypersensitivity over time. Quantitative real-time polymerase chain reaction and Western blot analysis were performed to investigate NL expression, and NLs were overexpressed in the rat spinal cord using lentiviral vectors. Immunofluorescence staining and whole-cell patch-clamp recordings were deployed to investigate the role of NLs in the development of BCP. Results We observed reduced expression levels of NL1 and NL2, but not of NL3, within the rat spinal cord, which were found to be associated with and essential for the development of BCP in our model. Accordingly, NL1 or NL2 overexpression in the spinal cord alleviated mechanical hypersensitivity of rats. Electrophysiological experiments indicated that NL1 and NL2 are involved in BCP via regulating γ-aminobutyric acid-ergic interneuronal synapses and the activity of glutamatergic interneuronal synapses, respectively. Conclusions Our observations unravel the role of NLs in cancer-related chronic pain and further suggest that inhibitory mechanisms are central features of BCP in the spinal dorsal horn. These results provide a new perspective and basis for subsequent studies elucidating the onset and progression of BCP.

Resumo em Inglês:

Abstract Background There are few studies related to Coronavirus Disease 2019 (COVID-19) on the prevalence and nature of pain symptoms after hospital discharge, especially in individuals who develop moderate to severe disease forms. Therefore, this study aimed to evaluate the presence of chronic pain in patients discharged after hospitalization for COVID-19, and the relationship between the presence of chronic pain and intensive care stay, demographics, and risk factors for the worst Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) outcome. Methods A cross-sectional observational study was carried out on patients with COVID-19 who recovered after hospitalization. Patients were recruited at the least 3 months after discharge and their hospital's health files were prospected. The variables evaluated were demographics, the severity of SARS-CoV-2 infection (considering the need for intensive care), and the presence of chronic pain. The results were shown in a descriptive manner, and multivariate analysis expressed as Odds Ratios (ORs) and respective Confidence Intervals (CIs) for the outcomes studied. Statistical significance was set at p < 0.05. Results Of 242 individuals included, 77 (31.8%) reported chronic pain related to COVID-19, with no correlation with the severity of infection. Female sex and obesity were associated with a higher risk for chronic pain with ORs of 2.69 (Confidence Interval [95% CI 1.4 to 5.0]) and 3.02 (95% CI 1.5 to 5.9). The limbs were the most affected areas of the body. Conclusion Chronic pain is common among COVID-19 survivors treated in hospital environments. Female sex and obesity are risk factors for its occurrence.

Resumo em Inglês:

Abstract Background There is no consensus on the most effective strategy for Postoperative Pulmonary Complication (PPC) reduction. This study hypothesized that a Goal-Directed Fluid Therapy (GDFT) protocol of infusion of predetermined boluses reduces the occurrence of PPC in patients undergoing elective open abdominal surgeries when compared with Standard of Care (SOC) strategy. Methods Randomized, prospective, controlled study, conducted from May 2012 to December 2014, with ASA I, II or III patients undergoing open abdominal surgeries, lasting at least 120 min, under general anesthesia, randomized into the SOC and the GDFT group. In the SOC, fluid administration was according to the anesthesiologist's discretion. In the GDFT, the intervention protocol, based on bolus infusion according to blood pressure and delta pulse pressure, was applied. Patients were postoperatively evaluated by an anesthesiologist blinded to the group allocation regarding PPC incidence, mortality, and Length of Hospital Stay (LOHS). Results Forty-two patients in the SOC group and 43 in the GDFT group. Nineteen patients (45%) in the SOC and 6 in the GDFT (14%) had at least one PPC (p = 0.003). There was no difference in mortality or LOHS between the groups. Among the patients with PPC, four died (25%), compared to two deaths in patients without PPC (3%) (p = 0.001). The LOHS had a median of 14.5 days in the group with PPC and 9 days in the group without PPC (p = 0.001). Conclusion The GDFT protocol resulted in a lower rate of PPC; however, the LOHS and mortality did not reduce.

Resumo em Inglês:

Abstract Background The incidence of arterial hypotension during induction of general anesthesia is influenced by the method of propofol administration, but there is a dearth of randomized clinical trials comparing bolus injection and target-controlled infusion in relation to arterial hypotension. This study seeks to compare the incidence of arterial hypotension between these two methods of propofol administration. Methods This prospective, randomized, single-center, non-blinded study included 60 patients (aged 35 to 55 years), classified as ASA physical status I or II, who were undergoing non-cardiac surgeries. They were randomly allocated using a computer to two groups based on the method of propofol administration during the induction of general anesthesia: the Target Group, receiving target-controlled infusion at 4 μg.mL−1, and the Bolus Group, receiving a bolus infusion of 2 mg.kg−1. Both groups also received midazolam 2 mg, fentanyl 3 μg.kg−1, and rocuronium 0.6 mg.kg−1. Over the first 10 minutes of anesthesia induction, Mean Arterial Pressure (MAP), Heart Rate (HR), level of Consciousness (qCON), and Suppression Rate (SR) were recorded every 2 minutes. Results Twenty-seven patients remained in the TCI group, while 28 were in the Bolus group. Repeated measure analysis using mixed-effects models could not reject the null hypothesis for the effect of group-time interactions in MAP (p = 0.85), HR (p = 0.49), SR (p = 0.44), or qCON (p = 0.72). The difference in means for qCON (60.2 for TCI, 50.5 for bolus, p < 0.001), MAP (90.3 for TCI, 86.2 for bolus, p < 0.006), HR (76.2 for TCI, 76.9 for bolus, p = 0.93), and SR (0.01 for TCI, 5.5 for bolus, p < 0.001), irrespective of time (whole period means), revealed some significant differences. Conclusion Patients who received propofol bolus injection exhibited a lower mean arterial pressure, a greater variation in the level of consciousness, and a higher suppression rate compared to those who received it as a target-controlled infusion. However, the interaction effect between groups and time remains inconclusive.

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Abstract Background The escalation of surgeries for high-risk patients in Low- and Middle-Income Countries (LMICs) lacks evidence on the positive impact of Intensive Care Unit (ICU) admission and lacks universal criteria for allocation. This study explores the link between postoperative ICU allocation and mortality in high-risk patients within a LMIC. Additionally, it assesses the Ex-Care risk model's utility in guiding postoperative allocation decisions. Methods A secondary analysis was conducted in a cohort of high-risk surgical patients from a 800-bed university-affiliated teaching hospital in Southern Brazil (July 2017 to January 2020). Inclusion criteria encompassed 1431 inpatients with Ex-Care Model-assessed all-cause postoperative 30-day mortality risk exceeding 5%. The study compared 30-day mortality outcomes between those allocated to the ICU and the Postanesthetic Care Unit (PACU). Outcomes were also assessed based on Ex-Care risk model classes. Results Among 1431 high-risk patients, 250 (17.47%) were directed to the ICU, resulting in 28% in-hospital 30-day mortality, compared to 8.9% in the PACU. However, ICU allocation showed no independent effect on mortality (RR = 0.91; 95% CI 0.68‒1.20). Patients in the highest Ex-Care risk class (Class IV) exhibited a substantial association with mortality (RR = 2.11; 95% CI 1.54-2.90) and were more frequently admitted to the ICU (23.3% vs. 13.1%). Conclusion Patients in the highest Ex-Care risk class and those with complications faced elevated mortality risk, irrespective of allocation. Addressing the unmet need for adaptable postoperative care for high-risk patients outside the ICU is crucial in LMICs. Further research is essential to refine criteria and elucidate the utility of risk assessment tools like the Ex-Care model in assisting allocation decisions.

Resumo em Inglês:

Abstract There is growing interest in using cannabinoids across various clinical scenarios, including pain medicine, leading to the disregard of regulatory protocols in some countries. Legislation has been implemented in Brazil, specifically in the state of São Paulo, permitting the distribution of cannabinoid products by health authorities for clinical purposes, free of charge for patients, upon professional prescription. Thus, it is imperative to assess the existing evidence regarding the efficacy and safety of these products in pain management. In light of this, the São Paulo State Society of Anesthesiology (SAESP) established a task force to conduct a narrative review on the topic using the Delphi method, requiring a minimum agreement of 60% among panelists. The study concluded that cannabinoid products could potentially serve as adjuncts in pain management but stressed the importance of judicious prescription. Nevertheless, this review advises against their use for acute pain and cancer-related pain. In other clinical scenarios, established treatments should take precedence, particularly when clinical protocols are available, such as in neuropathic pain. Only patients exhibiting poor therapeutic responses to established protocols or demonstrating intolerance to recommended management may be considered as potential candidates for cannabinoids, which should be prescribed by physicians experienced in handling these substances. Special attention should be given to individual patient characteristics and the likelihood of drug interactions.

Resumo em Inglês:

Abstract Background Prior research has established the effectiveness of magnesium in relieving postoperative pain. This article aims to evaluate magnesium sulfate for perioperative analgesia in adults undergoing general abdominal surgery under general anesthesia. Objective The primary aim was to assess pain scores at 6 and 24 hours postoperatively in patients receiving magnesium sulfate vs. the control group. Secondary outcomes were postoperative opioid consumption, perioperative complications, and time to rescue analgesia. Methods A comprehensive database search identified studies comparing magnesium sulfate with control in adults undergoing general anesthesia for general abdominal surgery. Using random-effects models, data were presented as mean ± Standard Deviation (SD) or Odds Ratios (OR) with corresponding 95% Confidence Intervals (95% CI). A two-sided p-value < 0.05 was considered statistically significant. Results In total, 31 studies involving 1762 participants met the inclusion criteria. The magnesium group showed significantly lower postoperative pain scores at both early (within six hours) and late (up to 24 hours) time points compared to the control group. The early mean score was 3.1 ± 1.4 vs. 4.2 ± 2.3, and the late mean score was 2.3 ± 1.1 vs. 2.7 ± 1.5, resulting in an overall Mean Difference (MD) of −0.72; 95% CI −0.99, −0.44; p < 0.00001. The magnesium group was associated with lower rates of postoperative opioid consumption and shivering and had a longer time to first analgesia administration compared to the saline control group. Conclusion Magnesium sulfate administration was linked to reduced postoperative pain and opioid consumption following general abdominal surgery.

Resumo em Inglês:

Abstract Background To explore the median effective dose (ED50) and 95% effective dose (ED95) of remimazolam besylate combined with alfentanil for adult gastroscopy. Methods This prospective studyenrolled 31 patients scheduled to painless gastroscopy at Anhui No. 2 Provincial People's Hospital between April and May, 2022. 5 µg.kg−1 of alfentanil hydrochloride was used for pre-analgesia. The initial single loading dose of remimazolam besylate was 0.12 mg.kg−1, increased or reduced by 0.01 mg.kg−1 for the next patient with modified Dixon sequential method. The modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S) was used to assess sedation. Results Combined with alfentanil, the ED50 of remimazolam besylate was 0.147 mg.kg−1 (95% CI: 0.138-0.160 mg.kg−1) and ED95 0.171 mg.kg−1 (95% CI: 0.159-0.245 mg.kg−1). The induction time after injection of remimazolam besylate was 70 ± 25 s, with the anesthesia recovery time and the observation time in resuscitation room 5.13 ± 2.13 min and 2.32 ± 1.6 min, respectively. Twenty nine patients’ vital signs were within acceptable limits during gastroscopy. Conclusions The ED50 of remimazolam besylate combined with alfentanil for painless gastroscopy was 0.147 mg.kg−1, and the ED95 was 0.171 mg.kg−1.