Type 2 Diabetes Mellitus with Tight Glucose Control and Poor Pre-Injury Stair Climbing Capacity May Predict Postoperative Delirium: A Secondary Analysis.

(1) Background: Previous evidence demonstrates that tight glycemic control and good physical function could reduce the risk of delirium. This study aimed to investigate whether the occurrence of postoperative delirium (POD) in older hip fracture surgery patients is associated with preoperative glycemic control factors or pre-injury physical performance. (2) Methods: Three-hundred and nine individuals aged over 65 years and scheduled for hip fracture surgery were included at a single center. Glycemic control factors and pre-injury physical performance were assessed preoperatively. The presence of delirium was assessed using the Confusion Assessment Method on postoperative hospitalization days. Univariate and multivariable logistic regression models and a risk prediction model of POD were established. (3) Results: Among the 309 patients, 52 (16.83%) experienced POD during the hospital stay. The numbers of pre-injury physical performance and type 2 diabetes mellitus (T2DM) patients were significantly different in the POD and non-POD groups. The multivariable model showed that development of delirium was significantly explained by preoperative fasting blood glucose (FBG) (OR 0.804, p = 0.004), stair climbing (OR 0.709, p = 0.003), T2DM (odds ratio (OR) 3.654, p = 0.001), and age-adjusted Charlson comorbidity index (ACCI) (OR 1.270, p = 0.038). The area under the receiver operating characteristic curve (AUROC) of the risk prediction model including those covariates was 0.770. (4) Conclusions: More older T2DM patients develop POD after hip fracture surgery than patients without T2DM. A simple assessment of preoperative FBG and pre-injury stair climbing capacity may identify those at high risk for the development of POD. Higher preoperative FBG and good pre-injury stair climbing capacity are protective factors for POD.

Protective effect of vitamin C on DNA damage in surgery-induced cognitive dysfunction in APP/PS1 mice.

Postoperative cognitive impairment is more likely to occur in elderly patients and in those with neurodegenerative diseases. The mechanisms underlying this impairment include neuroinflammation and oxidative stress. The increase in reactive oxygen species during oxidative stress causes cellular and molecular injury to neurons, including DNA damage, which aggravate brain dysfunction. Vitamin C has antioxidant effects and improves cognitive function in patients with Alzheimer's disease. However, it is unclear whether it can ameliorate surgery-induced cognitive impairment by inhibiting oxidative stress. In this study, 6-month-old mice overexpressing mutant amyloid precursor protein and presenilin-1 (APP/PS1) were subjected to laparotomy. The open field and fear conditioning tests were used to assess cognitive function. Mice that underwent surgery showed cognitive impairment without changes in spontaneous locomotor activity. Oxidative stress, DNA damage and inflammatory mediators were increased in the hippocampus after surgery. The expression levels of non-homologous end-joining DNA repair-associated proteins, including Ku heterodimer, DNA-dependent protein kinase catalytic subunit, X-ray repair cross complementing 4 (XRCC4) and XRCC4-like factor, were increased after surgery. Vitamin C pretreatment effectively attenuated cognitive dysfunction induced by surgery and reduced oxidative stress and DNA damage. Our findings suggest that DNA damage plays an important role in surgery-induced cognitive dysfunction, and that vitamin C pretreatment may have therapeutic potential as a preventative approach for the cognitive impairment.

Effects of a fixed low-dose ropivacaine with different volume and concentrations on interscalene brachial plexus block: a randomized controlled trial.

BACKGROUND: Ultrasound guidance has reduced the amount of local anesthetics to achieve a successful block. Previous studies of the relationship between the volume or concentration of local anesthetics and the effects of the block were based on relatively high doses of local anesthetics. We tested the hypothesis that providing low dose of ropivacaine at three combinations of volumes and concentrations for ultrasound-guided interscalene brachial plexus block would produce different effects in the aspect of onset time, pain control and the incidence of side effects. METHODS: Ninety-nine patients undergoing elective arthroscopic shoulder surgery were randomized to receive an ultrasound guided combined with nerve stimulator mediated interscalene block with ropivacaine 0.75 % (6.7 ml, Group 0.75), 0.5 % (10 ml, Group 0.5) or 0.25 % (20 ml, Group 0.25). The primary end point was the onset time of the sensory blockade, assessed by using a pinprick in the C5-6 dermatome. The secondary end points included the onset time of the motor blockade, block success rate, postoperative pain rating score, rescue analgesics requirement, sleep quality, strength of the hand on the block side,and the incidence of hemi-diaphragmatic paresis which was evaluated by ultrasonography. RESULTS: There was a statistically significant difference of the sensory block median onset times among Group 0.75 (5 min), Group 0.5 (10 min) and Group 0.25 (20 min). One patient in Group 0.5 and 20 patients in Group 0.25 did not achieve a complete motor block within 30 min, which were also significantly different. No significant difference was observed in postoperative analgesia, decrease of handgrip strength and the incidence of hemi-diaphragmatic paresis among the 3 groups. CONCLUSIONS: This study demonstrates that ropivacaine 50 mg as 0.25, 0.5 or 0.75 % solution for interscalene brachial plexus block before arthroscopic shoulder surgery produces comparable blockade with few side effects, while 0.75 % seems to be more preferable as it is associated with faster onset time. TRIAL REGISTRATION: ChiCTR-TRC-13004058 . Registered 4 December 2013.

Effective background infusion rate of ropivacaine 0.2% for patient-controlled interscalene brachial plexus analgesia after rotator cuff repair surgery.

BACKGROUND: Continuous interscalene nerve block (CISB) is considered to be the most effective method for postoperative analgesia after shoulder surgery with prolonged severe pain. This study was performed to evaluate the minimum effective background infusion rate and the effective background infusion rate of ropivacaine 0.2% for CISB after arthroscopic rotator cuff repair surgery in 95% of patients. METHODS: Patients scheduled for arthroscopic rotator cuff repair surgery under general anesthesia at Peking University Third Hospital were prospectively enrolled from December 2011 to May 2012. Preoperatively, an interscalene catheter (ISC) was placed under the guidance of ultrasound and nerve stimulation in each patient. Consecutively, 30 patients with successful nerve block were included. A continuous infusion of ropivacaine 0.2% with a 5 ml patient-controlled bolus available hourly was started at postoperative anesthesia care unit (PACU) after completion of surgery. The initial background infusion rate was 6 ml/h, which was subsequently varied for each consecutive patient according to the analgesic effects of the previous one. The minimum effective background rate was determined using the Dixon and Massey up-and-down method. The effective background rate in 95% of patients was calculated using isotonic analysis. RESULTS: The minimum effective background rate based on the Dixon and Massey up-and-down method was 2.8 ml/h (95% CI, 2.3-3.3 ml/h). The effective background rate in 95% of patients calculated with the isotonic regression analysis was 4.4 ml/h (95% CI, 3.8-6.5 ml/h). CONCLUSION: The effective background rate for patient-controlled interscalene brachial plexus analgesia after shoulder surgery in 50% and 95% of the patients was 2.8 and 4.4 ml/h, respectively.

[Influence of inhaled anesthesia on bispectral index of elderly patients with cognitive decline].

OBJECTIVE: To investigate the influence of inhaled anesthesia on bispectral index (BIS) of elderly patients with cognitive decline at loss of consciousness and regain of consciousness, and on deepening of sedation. METHODS: The patients aged more than 65 years undergoing elective operations from January 2012 to September 2012 were recruited, then 60 cognitive intact patients and 60 cognitive decline patients were screened by mini-mental state examinations. Inhaled anesthesia was administered using sevoflurane. BIS's of the two groups at loss of consciousness and regain of consciousness, and during end-tidal concentration of sevoflurane (CETSev) changing from 0.7% to 2.8% were recorded. The data were compared with independent-samples t test and repeated-measures general linear model of ANOVA. RESULTS: In the study, 117 patients finshed the investigation, The BIS's of the cognitive decline group at loss of consciousness were significantly higher than those of the cognitive intact group (P<0.01). There were no significant differences at regain of consciousness between the two groups (P>0.05). The BIS's of the cognitive decline group during CETSev changing from 0.7% to 2.8% were significantly lower than those of the cognitive intact group (P<0.05). The BIS's of the cognitive decline group at CETSev 0.7%, 1.05%, 1.4% and 1.75% were significantly lower than those of the cognitive intact group (P<0.05), but there were no significant differences at CETSev 2.1%, 2.45% and 2.8% between the two groups (P>0.05). CONCLUSION: During inhaled anesthesia, the BIS of the elderly patients with cognitive decline at loss of consciousness is higher than that of the patients with cognitive intact, The BIS of elderly patients with cognitive decline on deepening of anesthesia is lower than that of the patients with cognitive intact, especially during light anesthesia, and its mechanisms may attribute to cognitive decline related neurodegeneration and neurotransmitter system dysfunction.

[Effects of continuous interscalene brachial plexus block plus general anesthesia versus general anesthesia alone on perioperative management of arthroscopic rotator cuff repair surgery].

OBJECTIVE: To compare continuous interscalene brachial plexus block (CISB) in the patients undergoing rotator cuff repair surgery. METHODS: A total of 60 patients undergoing rotator cuff repair surgery were randomly assigned to either ISB plus GA group (ISB + GA group) or GA group. Preoperatively, an interscalene catheter was placed in the ISB + GA group patients. Both groups received general anesthesia. The intraoperative mean arterial pressure (MAP) at the level of external acoustic meatus was maintained at a target of 60 - 65 mm Hg with a continuous infusion of remifentanil. Postoperatively, the patients in the ISB + GA and GA groups received CISB and patient controlled intravenous analgesia (PCIA) respectively for 48 h. RESULTS: Surgical field conditions were similar in two groups (P = 1.000). Compared to the GA group, the consumption of remifentanil [(0.04 ± 0.03) vs (0.14 ± 0.03) µg×kg(-1)×min(-1), P < 0.01] and the inhalational concentration of sevoflurane(1.80% ± 0.5% vs 2.1% ± 0.5%, P < 0.05)were lower in the ISB + GA group. Compared to the GA group, the values of MAP and heart rate (HR) were lower at all postoperative time-points in the ISB + GA group(P < 0.05). The postoperative measurements of numerical rating pain score (NRPS) were lower (P < 0.01) and the level of patient satisfaction was greater in the ISB + GA group [8(6 - 10) vs 7 (5 - 10), P < 0.01]. CONCLUSION: In comparisons with GA alone for rotator cuff repair surgery, the combined uses of ISB and GA may achieve a better perioperative control of hemodynamic responses, a markedly reduced consumption of general anesthetics, a rapid recovery of consciousness from anesthesia, superior analgesia with fewer side effects and greater patient satisfaction.

[Effect of enhanced ultrasound guiding on brachial plexus block].

OBJECTIVE: To assess whether the enhanced imaging technology can improve the needle visibility during ultrasound-guided auxillary brachial plexus block. METHODS: After obtaining informed consent, 60 ASA (American Society of Anesthesiologists) I-II patients undergoing forearm or hand surgery were enrolled in this prospective, randomized, double-blind study. The patients were randomly assigned to two groups, the common image group (n=30) and enhanced image group (n=30). Ultrasound was used in guiding the block of the four branches of brachial plexus, i.e. the median, radial, ulnar and musculocutaneous nerves. In the enhanced image group a special function key "Multi-beam enhance" (MBe) was turned on during the needle insertion. After the nerve stimulator identification of the median, radial, ulnar and musculocutaneous nerves, 10 mL of 0.5% ropivacaine was injected near each nerve. The operating time, the visibility of the needle, the depth of each nerve, the onset time of the block, and the complications related to the block were assessed and recorded. RESULTS: The operating time was significantly shorter in the enhanced image group compared with the common image group [(2.63±0.81) min vs. (5.07±1.89) min, P=0.01]. The visibility of the needle was better in enhanced image group when the radial and musculocutaneous nerve blocks were performed (P<0.05). CONCLUSION: The enhanced image technology can reduce the operating time and improve the visibility of the needle during the peripheral nerve block for the nerve which is relatively deep.