Abstract in English:

Abstract Background: Difficult airway, characterized by difficult mask ventilation and intubation, is common in obese patients undergoing surgery. The purpose of this study was to evaluate and compare the prognostic efficiency of ultrasound-measured anterior cervical soft tissue parameters as an indicator of difficult airway during anesthesia induction in obese patients. Methods: This prospective, double-blind, observational study was conducted at Balikesir University Faculty of Medicine Hospital between March 2020 and March 2022. A total of 157 patients age ≥ 18 (BMI ≥ 30 kg.m−2), without previous head and neck surgery were included in the study. Anterior cervical soft tissue measurements were performed at three levels; minimum distance between the hyoid bone and skin at the level of the hyoid bone; (DSHB), distance between the midpoint of the epiglottis and skin at the level of the thyrohyoid membrane; (DSE), distance between the anterior commissure of vocal cords and skin at the vocal cord level; (DSV). The Han scale was used to assess difficult mask ventilation and the Cormack-Lehane scale was used to assess difficult laryngoscopy. Results: In the difficult laryngoscopy group, the mean values of DSHB, DSE and DSV were 18.5 ± 3.5, 18.3 ± 3.8, and 18.6 ± 3.4, respectively. The AUC values for DSHB, DSE, and DSV were 0.845, 0.827, and 0.850, respectively. Anterior cervical measurements showed a better predictive value for difficult laryngoscopy compared to difficult mask ventilation. Conclusion: Ultrasonographic measurements were predictive for difficult laryngoscopy and ventilation with better correlation in laryngoscopy.

Abstract in English:

Abstract Background: The primary aim of this proof-of-concept study was to investigate whether the Cardiac Power Index (CPI) could be a novel alternative method to assess fluid responsiveness in the prone position. Methods: Patients undergoing scheduled elective lumbar spine surgery in the prone position under general anesthesia were enrolled in the criteria of patients aged 19–75 years with American Society of Anesthesiologists (ASA) physical status I–II. The hemodynamic variables were evaluated before and after changes in posture after administering a colloid bolus (5 mL.kg−1)in the prone position. Fluid responsiveness was defined as an increase in the Stroke Volume Index (SVI) ≥ 10%. Results: A total of 28 patients were enrolled. In responders, the CPI (median [1/4Q–3/4Q]) decreased to 0.34 [0.28–0.39] W.m−2 (p = 0.035) after the prone position. After following fluid loading, CPI increased to 0.48 [0.37–0.52] W.m−2 (p < 0.008), and decreased SVI (median [1/4Q –3/4Q]) after prone increased from 26.0 [24.5–28.0] mL.m−2 to 33.0 [31.0–37.5] mL.m−2 (p = 0.014). Among non-responders, CPI decreased to 0.43 [0.28–0.53] W.m−2 (p = 0.011), and SVI decreased to 29.0 [23.5–34.8] mL.m−2 (p < 0.009). CPI exhibited predictive capabilities for fluid responsiveness as a receiver operating characteristic curve of 0.78 [95% Confidence Interval, 0.60–0.95; p = 0.025]. Conclusion: This study suggests the potential of CPI as an alternative method to existing preload indices in assessing fluid responsiveness in clinical scenarios, offering potential benefits for responders and non-responders.

Abstract in English:

Abstract Background: Kidney transplant recipients face complex perioperative challenges due to comorbidities from chronic kidney disease. This study aimed to assess perioperative complications in kidney transplant recipients and evaluate the association between the Charlson Comorbidity Index (CCI) and complication severity using the Clavien-Dindo (CD) classification. Methods: A prospective cohort study conducted at a tertiary hospital in South Brazil from September 2020 to March 2022, including 230 adult kidney transplant recipients. Data on demographics, comorbidities, and complications were collected. Complications were categorized using the CD scale, and their relationship with CCI was analyzed using univariate and multivariate Cox regression. Results: Mean age was 49.2 ± 12.7 years, with 58.7% male recipients. The mean CCI score was 3.65 ± 1.5 points. Intraoperative complications occurred in 10.9% of patients, with notable issues including bleeding and airway difficulties. In the immediate postoperative period, 9.1% required urgent dialysis. In the 30-day follow-up, 57.8% had delayed graft function, 21.7% infections, 11.3% had vascular complications, and the mortality was 1.7%. CCI was not a significant predictor of severe complications; however, congestive heart failure was strongly associated with severe complications (HR = 6.6 95% CI 2.6–6.7, p < 0.001). Conclusions: Despite a low overall comorbidity profile, kidney transplant recipients faced significant perioperative challenges. The lack of a significant association between the CCI score and severe complications suggests that traditional risk assessment tools may not fully capture the risks specific to the early postoperative period in kidney transplantation, and future research should focus on developing more refined risk assessment models for chronic kidney disease patients.

Abstract in English:

Abstract Background: Superior Vena Cava (SVC) diameter and collapsibility index, dynamic measures of fluid responsiveness, have been successfully utilized as echocardiographic indices for fluid responsiveness in ventilated septic patients. Whether these measurements are correlated with Central Venous Pressure (CVP) measurements in liver transplant patients is unknown. We sought to assess the correlation of maximum and minimum SVC diameter and SVC collapsibility index measurements obtained intraoperatively by Transesophageal Echocardiography (TEE) with those of simultaneously recorded CVP measurements obtained through a right atrial port of a pulmonary artery catheter. The secondary aim of the study was to assess the correlation between SVC measurements and simultaneously obtained thermodilution cardiac index measurements. Methods: Single center prospective observational trial of patients with end stage liver disease undergoing liver transplantation in an academic tertiary care center. Results: The minimum SVC exhibited a mild significant correlation with CVP as did the maximum SVC. The correlation between the SVC collapsibility index and CVP was not significantly different from zero. In our secondary analysis, the correlation between minimum SVC diameter and cardiac index was determined to be weak but non-zero as was the correlation between the maximum SVC diameter and cardiac index. The correlation between SVC collapsibility index and cardiac index was not different from zero. Conclusion: While statistically significant, the weak clinical correlation of intraoperative SVC measurements obtained by TEE make them unsuitable as a replacement for central venous pressure or thermodilution cardiac index measurements in liver transplant recipients.

Abstract in English:

Abstract Introduction: Acute Kidney Injury (AKI) following Liver Transplantation (LT) is associated with prolonged ICU and hospital stay, increased risk of chronic renal disease, and decreased graft survival. Intraoperative hypotension is a modifiable risk factor associated with postoperative AKI. We aimed to determine in which phase of LT hypotension has the strongest association with AKI: the anhepatic or neohepatic phase. Methods: This retrospective cohort study included adult patients undergoing LT between January 2010 and June 2022. Exclusion criteria were re-do or combined transplantations, preoperative dialysis, and early graft failure or death. Primary outcome was AKI as defined by KDIGO. Hypotension was Mean Arterial Pressure (MAP) below predefined thresholds in minutes. Risk adjusted logistic regression analysis considered hypotension in 3 periods: the total procedure, anhepatic phase, and neohepatic phase. Results: Our cohort included 1153 patients. The median MELD-NA score was 19 (IQR 11–28), and 412 (35.9%) were living-related donations. AKI occurred in 544 patients (47.2%). The unadjusted model showed an association with AKI for MAP < 60 mmHg (OR = 1.011 [1.0, 1.022], p = 0.047) and MAP < 55 mmHg (OR = 1.023 [1.002, 1.047], p = 0.040) in the anhepatic phase, and for MAP < 60 mmHg (OR = 1.032 [1.01, 1.056], p = 0.006) in the neohepatic phase. The adjusted model did not reach significance in the subgroups but did in the total procedure: MAP < 60 mmHg (OR = 1.005 [1.002, 1.008], p < 0.001) and MAP < 55 mmHg (OR = 1.008 [1.003–1.013], p = 0.004). Conclusion: Intraoperative hypotension is independently associated with AKI following LT. This association is seen during the anhepatic phase. Maintaining MAP above 60 mmHg may improve kidney function after LT.

Abstract in English:

Abstract Background: Dexmedetomidine, a highly selective alpha-2 adrenoceptor agonist with sedative and analgesic effects, has been suggested in recent studies to possess renoprotective properties. Dexmedetomidine may reduce the incidence of delayed graft function and contribute to effective pain control post-renal transplantation. The primary objective of this systematic review was to assess whether dexmedetomidine decreases the occurrence of delayed graft function in renal transplant patients. Methods: Databases including MEDLINE, EMBASE, and CENTRAL were comprehensively searched from their inception until March 2023. The inclusion criteria covered all Randomized Clinical Trials (RCTs) and observational studies comparing dexmedetomidine to control in adult patients undergoing renal transplant surgery. Exclusions comprised case series and case reports. Results: Ten RCTs involving a total of 1358 patients met the eligibility criteria for data synthesis. Compared to the control group, the dexmedetomidine group demonstrated a significantly lower incidence of delayed graft function (OR = 0.71, 95% CI 0.52-0.97, p = 0.03, GRADE: Very low, I2 = 0%). Dexmedetomidine also significantly prolonged time to initiation of rescue analgesia (MD = 6.73, 95% CI 2.32–11.14, p = 0.003, GRADE: Very low, I2 = 93%) and reduced overall morphine consumption after renal transplant (MD = −5.43, 95% CI −7.95 to −2.91, p < 0.0001, GRADE: Very low, I2 = 0%). The dexmedetomidine group exhibited a significant decrease in heart rate (MD = −8.15, 95% CI −11.45 to −4.86, p < 0.00001, GRADE: Very low, I2 = 84%) and mean arterial pressure compared to the control group (MD = −6.66, 95% CI −11.27 to −2.04, p = 0.005, GRADE: Very low, I2 = 87%). Conclusions: This meta-analysis suggests that dexmedetomidine may potentially reduce the incidence of delayed graft function and offers a superior analgesia profile as compared to control in adults undergoing renal transplants. However, the high degree of heterogeneity and inadequate sample size underscore the need for future adequately powered trials to confirm these findings.

Abstract in English:

Abstract Background: This study compares dexmedetomidine and buprenorphine as potential adjuvants for spinal anesthesia. Dexmedetomidine enhances sensory block and minimizes the need for pain medication, while buprenorphine, a long-acting opioid, exhibits a favorable safety profile compared to traditional opioids. Methods: PubMed, Cochrane and EMBASE were systematically searched in December 2023. Eligibility criteria: RCTs with patients scheduled for lower abdominal, pelvic, or lower limb surgeries; undergoing spinal anesthesia with a local anesthetic and buprenorphine or dexmedetomidine. Results: Eight RCTs involving 604 patients were included. Compared with dexmedetomidine, buprenorphine significantly reduced time for sensory regression to S1 (Risk Ratio [RR = −131.28]; 95% CI −187.47 to −75.08; I2 = 99%) and motor block duration (RR = −118.58; 95% CI −170.08 to −67.09; I2 = 99%). Moreover, buprenorphine increased the onset time of sensory block (RR = 0.42; 95% CI 0.03 to 0.81; I2 = 93%) and increased the incidence of postoperative nausea and vomiting (RR = 4.06; 95% C11.80 to 9.18; I2 = 0%). No significant differences were observed in the duration of analgesia, onset time of motor block, time to achieve the highest sensory level, shivering, hypotension, or bradycardia. Conclusions: The intrathecal administration of buprenorphine, when compared to dexmedetomidine, is linked to reduction in the duration of both sensory and motor blocks following spinal anesthesia. Conversely, buprenorphine was associated with an increased risk of postoperative nausea and vomiting and a longer onset time of sensory block. Further high-quality RCTs are essential for a comprehensive understanding of buprenorphine’s effects compared with dexmedetomidine in spinal anesthesia.