Application of Dexmedetomidine Sedation Combined With Suprascapular Nerve Block and Axillary Nerve Block in Shoulder Arthroscopy, A Randomized Single-Blind Study

Objective: The aim of the present study was to evaluate the anesthetic and analgesic effects of dexmedetomidine combined with suprascapular nerve block and axillary nerve block in shoulder arthroscopy.Methods: A total of 60 patients were randomly divided into the experimental group (DEX group) and the control group (GA group) via a random number table method. Dexmedetomidine sedation combined with suprascapular nerve block and axillary nerve block was used in the DEX group, while general anesthesia with tracheal intubation combined with interscalene brachial plexus block was used in the GA group. The perioperative indexes, intraoperative hemodynamics, cerebral oxygen saturation, and postoperative pain score, as well as any complications, were compared between the two groups.Results: The anesthesia duration (p < 0.05) and postoperative monitoring time (p < 0.05) in the DEX group were significantly shorter than those in the GA group. At most time points during the anesthesia, the cerebral oxygen saturation (p < 0.05) and mean arterial pressure (p < 0.05) in the DEX group were significantly higher than those in the GA group. Additionally, the decrease in the cerebral oxygen saturation and mean arterial pressure in the GA group was significantly higher than that in the DEX group (p < 0.05). The pain score of DEX group 12 h after operation significantly lower than that in the GA group (p < 0.05), and the incidence of postoperative hypoxemia along with nausea and vomiting in the GA group was significantly higher than that in the DEX group (p < 0.05).Conclusion: Dexmedetomidine combined with suprascapular nerve block and axillary nerve block could reduce the incidence of hypoxemia, while the approach demonstrated better hemodynamic stability, fully ensured the cerebral blood perfusion, and exhibited better anesthetic and analgesic effects, meaning it could be safely and effectively applied in shoulder arthroscopy procedures.

The effect of pulsatile versus non-pulsatile flow during cardiopulmonary bypass on cerebral oxygenation: A randomized trial

Background The present study aims to compare regional oxygen supply determined by Near-Infrared Spectroscopy in the course of pulsatile perfusion with non-pulsatile perfusion during cardiopulmonary bypass in patients undergoing valvular heart surgery. Methods In this prospective randomized single-blinded trial, we enrolled adult subjects aged 18–65 years scheduled for elective valvular heart repair/replacement surgery with non-stenotic carotid arteries, employing a consecutive sampling method. Eligible patients were then randomly assigned in a 1:1 ratio to pulsatile or non-pulsatile perfusion during aortic cross-clamp. The primary outcome was regional cerebral oxygenation monitored by Near-Infrared Spectroscopy in each group. Results Seventy patients were randomly assigned, and each group comprised 35 patients. Mean age was 46.8 and 46.5 years in pulsatile and non-pulsatile groups, respectively. There were no significant between-group differences in regional cerebral oxygen saturation at different time points of cardiopulmonary bypass ( p-value for analysis of variance repeated measures: 0.923 and 0.223 for left and right hemispheres, respectively). Moreover, no significant differences in regional cerebral oxygen saturation levels from baseline between pulsatile and non-pulsatile groups at all desired time points for the left ( p = 0.51) and right ( p = 0.22) hemispheres of the brain were detected. Conclusion Pulsatile perfusion during cardiopulmonary bypass does not offer superior regional cerebral oxygenation measured by Near-Infrared Spectroscopy than non-pulsatile perfusion during cardiopulmonary bypass. Nonetheless, the efficacy of pulsatile flow in the subgroup of patients in whom cerebral blood flow is impaired due to carotid artery stenosis needs to be explored and evaluated by this method in future studies.

Relationship Between Cerebral Hemodynamics, Tissue Oxygen Saturation, and Delirium in Patients With Septic Shock: A Pilot Observational Cohort Study

Background: Septic shock patients have tendencies toward impairment in cerebral autoregulation and imbalanced cerebral oxygen metabolism. Tissue Oxygen Saturation (StO2) and Transcranial Doppler (TCD) monitoring were undertaken to observe the variations of cerebral hemodynamic indices and cerebral/peripheral StO2 to find risk factors that increase the sepsis-associated delirium (SAD).Materials and Methods: The research cohort was chosen from septic shock patients received in the Department of Critical Care Medicine, Xiangya Hospital, Central South University between May 2018 and March 2019. These patients were separated into two groups, SAD and non-SAD as assessed by using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). Comparisons were made between the two groups in terms of peripheral StO2, fluctuations in regional cerebral oxygen saturation (rSO2), cerebral vascular automatic regulation function [Transient Hyperemic Response Ratio (THRR) index], cerebral hemodynamic index, organ function indicators, blood gas analysis indices, and patient characteristics.Results: About 39% of the patients (20/51) suffered from SAD. Nearly 43% of the patients died within 28 days of admission (22/51). Individuals in the SAD cohort needed a longer period of mechanical ventilation [5 (95% CI 2, 6) vs. 1 days (95% CI 1, 4), p = 0.015] and more time in ICU [9 (95% CI 5, 20) vs. 5 days (95% CI 3, 9), p = 0.042]; they also experienced more deaths over the 28-day period (65 vs. 29%, p = 0.011). The multivariate regression analysis indicated that independent variables associated with SAD were THRR index [odds ratio (OR) = 5.770, 95% CI: 1.222–27.255; p = 0.027] and the mean value for rSO2 was < 55% (OR = 3.864, 95% CI: 1.026–14.550; p = 0.046).Conclusion: Independent risk factors for SAD were mean cerebral oxygen saturation below 55% and cerebrovascular dysregulation (THRR < 1.09).

Abstract 11340: Increasing Mean Arterial Pressure or Cardiac Output in Comatose Out-of-Hospital Cardiac Arrest Patients Undergoing Targeted Temperature Management: Effects on Cerebral Tissue Oxygenation

Introduction: There are few data regarding the effects of norepinephrine-uptitration on global and regional hemodynamics in cardiac intensive care patients. Methods: We prospectively studied 10 OHCA patients at our cardiac intensive care unit. The trial consisted of 5 phases. The first 4 phases were achieved by titrating norepinephrine to reach targets of mean arterial pressure (MAP). First a MAP of 65 mmHg, second 75 mmHg, third 85 mmHg, fourth 65 mmHg again. The fifth phase was with a constant MAP of 65 mmHg but aiming at an increased PaCO2 from 6.5-7.3 kPa to increase cardiac output. During each phase, 20 minutes steady state was achieved before measurements. We measured hemodynamic variables with a Swan-Ganz catheter, arterial and mixed venous blood gases, and near-infrared spectroscopy at the forehead (cerebral oxygen saturation). Results: To obtain a MAP at 85 mmHg, norepinephrine was increased from 0.11±0.02 to 0.18±0.02 μg · kg–1 · min–1 (P < 0.001). Norepinephrine uptitration significantly increased MAP, systemic vascular resistance and pulmonary artery pressure, without affecting cardiac output or heart rate. After phase 3, norepinephrine was decreased to basal values, and all variables returned to baseline. Increasing pCO2, resulted in a significant increase in cardiac output and cerebral oxygen saturation, while decreasing systemic vascular resistance. MAP (and NE dose) was unaffected by increasing pCO2. Conclusions: A short-term increase in MAP with norepinephrine in resuscitated OHCA-patients is associated with increased SVR and PVR without affecting cardiac output or NIRS of the brain. An increase in CO caused by an increase in pCO2 and thereby a decreased SVR increased NIRS potentially improving brain oxygenation.

Lower cerebral oxygen utilization is associated with Alzheimer’s disease-related neurodegeneration and poorer cognitive performance among apolipoprotein E ε4 carriers

Oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) are markers of cerebral oxygen homeostasis and metabolism that may offer insights into abnormal changes in brain aging. The present study cross-sectionally related OEF and CMRO2 to cognitive performance and structural neuroimaging variables among older adults (n = 246, 74 ± 7 years, 37% female) and tested whether apolipoprotein E ( APOE)-ε4 status modified these associations. Main effects of OEF and CMRO2 were null (p-values >0.06), and OEF interactions with APOE-ε4 status on cognitive and structural imaging outcomes were null (p-values >0.06). However, CMRO2 interacted with APOE-ε4 status on language (p = 0.002), executive function (p = 0.03), visuospatial (p = 0.005), and episodic memory performances (p = 0.03), and on hippocampal (p = 0.006) and inferior lateral ventricle volumes (p = 0.02). In stratified analyses, lower oxygen metabolism related to worse language (p = 0.02) and episodic memory performance (p = 0.03) among APOE-ε4 carriers only. Associations between CMRO2 and cognitive performance were primarily driven by APOE-ε4 carriers with existing cognitive impairment. Congruence across language and episodic memory results as well as hippocampal and inferior lateral ventricle volume findings suggest that APOE-ε4 may interact with cerebral oxygen metabolism in the pathogenesis of Alzheimer’s disease and related neurodegeneration.

Effects on Cerebral Oxygen Balance in Coronary Artery Bypass Grafting: A Comparison of Conventional and Minimal Extracorporeal Circulation

Objective: To investigate the cerebral oxygen balance difference between minimal extracorporeal circulation (MECC) and conventional extracorporeal circulation (CECC) during coronary artery bypass grafting. Methods: 20 patients undergoing coronary artery bypass grafting with cardiopulmonary bypass (CPB) were divided into two groups, the CECC group (n=10) and the MECC group (n=10). Blood withdrawn from radial artery and right jugular vein were analyzed at the following timepoints: during the anesthesia induction (T1), before CPB (T2), the initiation of CPB (T3), aorta crossclamped (T4), after temperature decreased (T5), during stable hypothermia (T6), initiation of rewarming (T7), aorta unclamped (T8), after weaning of CPB (T9), end of the operation (T10).The artery oxygen content (CaO2 ) and cerebral oxygen extraction ratio (OER) were calculated. The mean artery pressure (MAP), hemoglobin (Hb), nasopharyngeal temperature (NPT), and pump perfusion flow were recorded during the operation. Results: (1) MAP and Hb of MECC group were significantly higher than those in the CECC group from T3 to T10 (P<0.05); perfusion flow in MECC group during CPB was significantly lower than those in CECC group (P<0.05); NPT in MECC group was significantly higher than those in CECC group (P<0.05). (2) During T3-T4 and T8-T9, jugular venous oxygen saturation in CECC group was significantly lower than those in MECC (P<0.05); OER in CECC group was significantly higher than those in MECC group (P<0.05). (3) The arterial lactic acid and venous lactic acid in these two groups were decreased gradually from T3 to T10. Thearteriovenous difference in lactic acid in CECC group were higher than those in MECC group during T3-T4 and T8-T9 (P<0.05). Conclusion: Patients undergoing coronary artery bypass grafting with MECC enjoy more stable blood pressure, less intense hemodilution and lighter temperature disturbance than those with CECC, which indicating a better cerebral oxygen balance in CABG.