Desflurane versus sevoflurane anesthesia and postoperative recovery in older adults undergoing minor- to moderate-risk noncardiac surgery - A prospective, randomized, observer-blinded, clinical trial

STUDY OBJECTIVE

The effect of volatile anesthetics on postoperative recovery in older adults is still not entirely clear. Thus, we evaluated the effect of desflurane versus sevoflurane anesthesia on speed of postoperative recovery in older adults eligible for same-day discharge. We further evaluated the incidence of postoperative nausea and vomiting (PONV), bispectral index (BIS) values, and S100B concentrations.

DESIGN

Single-center, prospective, observer-blinded, randomized clinical trial.

SETTING

Operating room.

PATIENTS

190 patients ≥65 years of age and scheduled for minor- to moderate-risk noncardiac surgeries.

INTERVENTIONS

Goal-directed administration of desflurane versus sevoflurane for maintenance of anesthesia with an intraoperative goal of BIS 50 ± 5.

MEASUREMENTS

The primary outcome was the time to anesthesia recovery, which was defined as the time between arrival at the post-anesthesia care unit (PACU) and reaching criteria for discharge from PACU, based on modified Aldrete score ≥ 12 points. Modified Aldrete scores were assessed at PACU arrival and thereafter in five-minute intervals. PONV was evaluated during PACU stay and the first three postoperative days, BIS values were recorded during PACU stay, and S100B values were measured before and after surgery, and on the second postoperative day.

MAIN RESULTS

95 patients were randomized to receive desflurane, and 95 patients to receive sevoflurane. We did not observe a significant difference in median duration of postoperative recovery between the groups (desflurane: 0 min [0;0]; sevoflurane: 0 min [0;0]; p = 0.245). 77 patients (81.1%) in the desflurane group and 84 patients (88.4%) in the sevoflurane group already had Aldrete scores ≥12 points upon arrival at PACU (p = 0.277). There was also no significant difference in the incidences of PONV (p = 0.606), postoperative BIS values (p = 0.197), and postoperative maximum S100B concentrations (p = 0.821) between the groups.

CONCLUSIONS

Despite previous reports, we did not observe significant faster recovery times after desflurane anesthesia. Both volatile anesthetics may be appropriate for same-day discharge in older adults.

Anesthesia, Anesthetics, and Postoperative Cognitive Dysfunction in Elderly Patients

Postoperative cognitive dysfunction (POCD) remains a major issue that worsens the prognosis of elderly surgery patients. This article reviews the current research on the effect of different anesthesia methods and commonly utilized anesthetics on the incidence of POCD in elderly patients, aiming to provide an understanding of the underlying mechanisms contributing to this condition and facilitate the development of more reasonable anesthesia protocols, ultimately reducing the incidence of POCD in elderly surgery patients.

Impact of anesthetics on rat hippocampus and neocortex: A comprehensive proteomic study based on label-free mass spectrometry

Anesthesia is regarded as an important milestone in medicine. However, the negative effect on memory and learning has been observed. In addition, the impact of anesthetics on postoperative cognitive functions is still discussed. In this work, in vivo experiment simulating a general anesthesia and ICU sedation was designed to assess the impact of two intravenous (midazolam, dexmedetomidine) and two inhalational (isoflurane, desflurane) agents on neuronal centers for cognition (neocortex), learning, and memory (hippocampus). More than 3600 proteins were quantified across both neocortex and hippocampus. Proteomic study revealed relatively mild effects of anesthetics, nevertheless, protein dysregulation uncovered possible different effect of isoflurane (and midazolam) compared to desflurane (and dexmedetomidine) to neocortical and hippocampal proteins. Isoflurane induced the upregulation of hippocampal NMDAR and other proteins of postsynaptic density and downregulation of GABA signaling, whereas desflurane and dexmedetomidine rather targeted mitochondrial VDAC isoforms and protein regulating apoptotic activity.

Effects of dexmedetomidine on dynamic lung compliance in general anesthesia with desflurane: A randomized controlled study

Objective

The aim of this study was to evaluate the effect of dexmedetomidine on lung compliance in patients under general anesthesia with desflurane.

Methods

This prospective, randomized, double-blind, controlled trial included 51 patients who received general anesthesia undergoing lower limb fracture surgery. Participants were assigned to either the experimental (loading dose of 0.25 μg/kg dexmedetomidine over 10 min, followed by a maintenance dose of 0.3 μg/kg/h until the end of the surgery) or control (0.9% saline) group. Anesthesia was maintained with desflurane, analgesics and muscle relaxants. The two groups were compared for hemodynamic parameters, dynamic lung compliance, oxygenation index, and postoperative complications.

Results

While dynamic lung compliance showed no significant difference between the two groups at T1 (P = 0.321), it was significantly higher in the experimental group at all other time points (all P < 0.001). In the control group, Cdyn at T4, T5, T6, and T7 were lower than that at T1 (P = 0.032, 0.043, 0.032 and 0.018, respectively). There were no significant between-group differences in the mean arterial pressure and heart rate. Compared to the control group, the experimental group had a higher oxygenation index at T1 (P < 0.001), T2 (P < 0.001), T3 (P < 0.001), T4 (P = 0.02), and T5 (P = 0.016) and significantly lower peak airway pressure at all time points (all P < 0.001). Both groups had comparable postoperative outcomes.

Conclusions

Dexmedetomidine infusion at a loading dose of 0.25 μg/kg and maintenance dose of 0.3 μg/kg/h improved dynamic lung compliance in patients receiving desflurane during general anesthesia.

Dual roles of anesthetics in postoperative cognitive dysfunction: Regulation of microglial activation through inflammatory signaling pathways

Postoperative cognitive dysfunction (POCD) is a prevalent clinical entity following surgery and is characterized by declined neurocognitive function. Neuroinflammation mediated by microglia is the essential mechanism of POCD. Anesthetics are thought to be a major contributor to the development of POCD, as they promote microglial activation and induce neuroinflammation. However, this claim remains controversial. Anesthetics can exert both anti- and pro-inflammatory effects by modulating microglial activation, suggesting that anesthetics may play dual roles in the pathogenesis of POCD. Here, we review the mechanisms by which the commonly used anesthetics regulate microglial activation via inflammatory signaling pathways, showing both anti- and pro-inflammatory properties of anesthetics, and indicating how perioperative administration of anesthetics might either relieve or worsen POCD development. The potential for anesthetics to enhance cognitive performance based on their anti-inflammatory properties is further discussed, emphasizing that the beneficial effects of anesthetics vary depending on dose, exposure time, and patients' characteristics. To minimize the incidence of POCD, we recommend considering these factors to select appropriate anesthetics.

Dementia risk after major elective surgery based on the route of anaesthesia: A propensity score-matched population-based cohort study

Background

Whether the route of anaesthesia is an independent risk factor for dementia remains unclear. Therefore, we conducted a propensity score-matched (PSM) population-based cohort study to compare dementia incidence among surgical patients undergoing different routes of anaesthesia.

Methods

The inclusion criteria were being an inpatient >20 years of age who underwent major elective surgery, defined as those requiring GA without or with inhalation anaesthetics or regional anaesthesia, and being hospitalised for >1 day between Jan 1, 2008 and Dec 31, 2019 in Taiwan. Patients undergoing major elective surgery were categorised into three groups according to the type of anaesthesia administered: noninhalation anaesthesia, inhalation anaesthesia, and regional anaesthesia, matched at a 1:1 ratio. The incidence rate (IR) of dementia was determined.

Findings

PSM yielded 63,750 patients (21,250 in the noninhalation anaesthesia group, 21,250 in the inhalation anaesthesia group, and 21,250 in the regional anaesthesia group). In the multivariate Cox regression analysis, the adjusted hazard ratios (aHRs; 95% confidence intervals) of dementia for the inhalation and noninhalation anaesthesia groups compared with the regional anaesthesia group were 20.16 (15.40-26.35; p < 0.001) and 18.33 (14.03-24.04; p < 0.001), respectively. The aHR of dementia for inhalation anaesthesia compared with noninhalation anaesthesia was 1.13 (1.03-1.22; p = 0.028). The IRs of dementia for the inhalation, noninhalation, and regional anaesthesia groups were 3647.90, 3492.00, and 272.99 per 100,000 person-years, respectively.

Interpretation

In this population based cohort study, the incidence of dementia among surgical patients undergoing general anaesthesia was higher than among those undergoing regional anaesthesia. Among patients undergoing general anaesthesia, inhalation anaesthesia was associated with a higher risk of dementia than noninhalation anaesthesia. Our results should be confirmed in a randomised controlled trial.

Funding

The study was partially supported by Lo-Hsu Medical Foundation, Lotung Poh-Ai Hospital (Funding Number: 10908, 10909, 11001, 11002, 11003, 11006, and 11013).

Preventing postoperative cognitive dysfunction using anesthetic drugs in elderly patients undergoing noncardiac surgery: a systematic review and meta-analysis

Postoperative cognitive dysfunction (POCD) is a common neurological system disorder in surgical patients. The choice of anesthetic can potentially reduce POCD. The authors performed this network meta-analysis to compare different anesthetic drugs in reducing the incidence of POCD for elderly people undergoing noncardiac surgery. We searched MEDLINE, EMBASE, the Cochrane Library, and the Web of Science for randomized controlled trials comparing the different anesthetic drugs for noncardiac surgery in elderly from inception until July, 2022. The protocol was registered on the PROSPERO database (CRD#42020183014). A total of 34 trials involving 4314 patients undergoing noncardiac surgery in elderly were included. The incidence of POCD for each anesthetic drug was placebo (27.7%), dexmedetomidine (12.9%), ketamine (15.2%), propofol (16.8%), fentanyl (23.9%), midazolam (11.3%), sufentanil (6.3%), sevoflurane (24.0%), and desflurane (28.3%). Pairwise and network meta-analysis showed dexmedetomidine was significantly reducing the incidence of POCD when compared with placebo. Network meta-analysis also suggested dexmedetomidine was significantly reducing the incidence of POCD when compared with sevoflurane. Sufentanil and dexmedetomidine ranked the first and second in reducing the incidence of POCD with the surface under the cumulative ranking curve value of 87.4 and 81.5%. Sufentanil and dexmedetomidine had the greatest possibility to reduce the incidence of POCD for elderly people undergoing noncardiac surgery.

CTRP6(C1q/Tumor Necrosis Factor (TNF)-related protein-6) alleviated the sevoflurane induced injury of mice central nervous system by promoting the expression of p-Akt (phosphorylated Akt)

Postoperative cognitive impairment and nervous system damage caused by anesthetics seriously affect patient’s postoperative recovery. Recent study has revealed that CTRP6 could alleviate apoptosis, inflammation and oxidative stress of nerve cells, thereby relieving nervous system damage induced by cerebral ischemia reperfusion. However, whether CTRP6 could relieve sevoflurane induced central nervous system injury is unclear. We stimulated C57BL/6 mice with sevoflurane and injected CTRP6 overexpression adenovirus vector. Next, H&E staining and TUNEL assays were performed to examine the effect of CTRP6 on sevoflurane induced injury of central nervous system. Finally, we isolated primary nerve cells of hippocampus. Flow cytometry and commercial kits were used for the detection of apoptosis and ROS levels of these cells. Western blotting was used for the detection of the expression level of p-Akt in central nervous tissues and primary cells. Results showed that sevoflurane induced injury and apoptosis of central nervous tissues. Overexpression of CTRP6 relieved apoptosis and injury of these tissues. CTRP6 inhibited the expression of cleaved caspase-3 and cleaved PARP in these tissues. Sevoflurane promoted apoptosis of primary cells and enhanced the expression of ROS and MDA in these cells. Overexpression of CTRP6 alleviated apoptosis and suppressed production of ROS and MDA in these cells. In addition, CTRP6 also enhanced the expression of p-Akt in primary cells. Taken together, our results suggested that CTRP6 relieved sevoflurane induced injury of central nervous tissues by promoting the expression of p-Akt. Therefore, the targeted drug of CTRP6 should be explored for the remission of these symptoms.

Effects of general anesthetics on synaptic transmission and plasticity

General anesthetics depress excitatory and/or enhance inhibitory synaptic transmission principally by modulating the function of glutamatergic or GABAergic synapses, respectively, with relative anesthetic agent-specific mechanisms. Synaptic signaling proteins, including ligand- and voltage-gated ion channels, are targeted by general anesthetics to modulate various synaptic mechanisms, including presynaptic neurotransmitter release, postsynaptic receptor signaling, and dendritic spine dynamics to produce their characteristic acute neurophysiological effects. As synaptic structure and plasticity mediate higher-order functions such as learning and memory, long-term synaptic dysfunction following anesthesia may lead to undesirable neurocognitive consequences depending on the specific anesthetic agent and the vulnerability of the population. Here we review the cellular and molecular mechanisms of transient and persistent general anesthetic alterations of synaptic transmission and plasticity.

Postoperative cognitive dysfunction in elderly patients undergoing hip arthroplasty

Even after successful hip arthroplasty, elderly patients who have undergone this procedure remain subject to cognitive decline and may collectively develop postoperative cognitive dysfunction (POCD). However, no consensus exists as to the risk factors resulting in a higher likelihood that a patient may present with this complication, and the aetiology of POCD is not well understood. We conducted a systematic review of papers concerning the influence of POCD-related risk factors in patients undergoing hip arthroplasty but limited the literature search to papers in English. A systematic and electronic search for manuscripts in the PubMed database was performed in order to identify all studies in which the risk factors for POCD were investigated. Articles were also obtained from the authors' files. Keywords for the search were postoperative cognitive dysfunction/change/impairment/decline/deficit, elderly/older/aged patients, and hip arthroplasty/replacement surgery. The evidence published to date suggests that POCD is a multifactorial disease, which includes an individual patient's characteristics, surgery, type of anaesthesia, and pain levels. All of these factors can increase the risk of POCD incidence. There are a number of factors that appear to influence the risk of early cognitive dysfunction after hip arthroplasty. Nevertheless, the specific mechanism and explicit risk factors associated with this cognitive dysfunction are not completely understood. Hip arthroplasty has made it possible for older patients to find relief from pain and improve their function, whereas it also increases the risk for suffering POCD that may affect these patients' quality of life and increase their mortality. Therefore, it is worthwhile investigating the mechanism of POCD in future studies in order to prevent and treat this condition.

Exploratory analyses of postanesthetic effects of desflurane using behavioral test battery of mice

Halogenated ethers, such as desflurane, sevoflurane, and isoflurane, are known to exert an array of effects besides sedation. However, the postanesthetic effects of desflurane remain undiscovered as no study has explored these effects systematically. Phenotypic screening using behavioral test batteries is a powerful method to identify such effects. In the present study, we behaviorally phenotyped desflurane-treated mice to investigate postanesthetic effects. We applied comprehensive behavioral test batteries measuring sensorimotor functions, anxiety, depression, sociability, attention, and learning abilities, starting 7 days after anesthesia performed with 8.0% desflurane for 6 h. Although our previous study revealed postanesthetic effects of isoflurane in adult mice, in the current study, desflurane-treated mice exhibited no such effects in any behavioral test. To further examine whether desflurane affect behavior in more early time point, we built up a new additional test battery, which carried out 1 day or 3 days after exposure to desflurane. Mice treated with desflurane 1 day before testing showed more slips than other two groups in the first trial, suggesting mild acute side effects of desflurane on motor coordination. These results suggest the safety of desflurane in clinical settings and imply that postanesthetic effects are unique to each halogenated ether.

Relationship Between mTOR Signaling Activation and Postoperative Neurocognitive Disorder in Aged Rats

BACKGROUND

Although incidence rates of postoperative neurocognitive disorder (PND) in aged individuals following noncardiac major surgery are rising as individuals are living longer, the mechanism of PND remains poorly understood. We wondered if mammalian target of rapamycin (mTOR) signaling might be associated with PND since mTOR controls some essential intracellular events.

OBJECTIVE

To investigate whether surgery activates the mTOR signaling pathway in aged rats, leading to PND, and whether the mTOR inhibitor, rapamycin, can be used to alleviate PND.

METHODS

We randomly assigned aged rats to four groups: normal control (C), isoflurane (I), surgery (S), and rapamycin (R). Then, we anesthetized Groups I, S, and R, following which, Groups S and R underwent a splenectomy. After surgery, Group R was administered rapamycin. We used the Morris water maze to test the rats' spatial learning and memory after surgery.

RESULTS

In Group S, escape latency (ie, the time to find the platform) was markedly higher, and the ratio of swimming time in the target quadrant was lower, compared to the other groups. In Group R, escape latency was markedly lower as compared with Group S, and the ratio of swimming time in the target quadrant was higher.

CONCLUSIONS

Our results indicate that an altered mTOR signaling pathway after a splenectomy causes PND in aged rats, which can be alleviated by rapamycin.

A randomized trial of desflurane or sevoflurane on postoperative quality of recovery after knee arthroscopy

Background

Studies have described different recovery profiles of sevoflurane and desflurane typically early after surgery.

Methods

We conducted a randomized superiority trial to determine whether Overall Recovery 3 days after knee arthroscopy would be superior with desflurane. Adult participants undergoing knee arthroscopic surgery with general anesthesia were randomized to either desflurane or sevoflurane general anesthesia. Intraoperative and postoperative drugs and analgesics were administered at the discretion of the anesthesiologist. Postoperative quality of recovery was assessed using the “Postoperative Quality of Recovery Scale”. The primary outcome was Overall Recovery 3 days after surgery and secondary outcomes were individual recovery domains at 15 minutes, 40 minutes, 1 day, 3 days, 1 month, and 3 months. Patients and researchers were blinded.

Results

300 patients were randomized to sevoflurane or desflurane (age 51.7±14.1 vs. 47.3±13.5 years; duration of anesthesia 24.9±11.1 vs. 23.3±8.3 minutes). The proportion achieving baseline or better scores in all domains increased over the follow-up period in both groups but was not different at day 3 (sevoflurane 43% vs. desflurane 37%, p = 0.314). Similarly, rates of recovery increased over time in the five subdomains, with no differences between groups for physiological, p = 0.222; nociceptive, p = 0.391; emotive, p = 0.30; Activities-of-daily-living, p = 0.593; and cognitive recovery, p = 0.877.

Conclusion

No significant difference in the quality of recovery scale could be shown using sevoflurane or desflurane general anesthesia after knee arthroscopy in adult participants.

Effects of sevoflurane and desflurane on early cognitive changes after thyroid surgery: interim results

The study is being conducted at the 1st Department of Anaesthesiology, the Centre of Abdominal Surgery, the Centre of Anaesthesiology, Intensive Care and Pain Management of Vilnius University Hospital Santaros Klinikos.

Background

These are primary results of a randomized double-blinded study comparing postoperative changes in cognitive functions and the effect of desflurane and sevoflurane on these changes.

Materials and methods

The study includes patients of ≥40 years of age undergoing elective thyroid surgery under general anaesthesia. Patients were randomly allocated to either sevoflurane or desflurane group. Cognitive testing (memory, attention, and reasoning tasks) was performed a day before surgery and repeated 24 hours postoperatively. A decrease of 20% in the postoperative score was considered as postoperative cognitive dysfunction (POCD).

Results

At present 38 patients are included in the study. Median decrease in the postoperative score was 2.7% (IQR 16.7). The incidence of POCD was 2.6%. Significantly decreased memory scores were observed in 15.8% of patients. Both study groups were comparable based on demography, duration of anaesthesia, intraoperative opioids, postoperative pain, and satisfaction. No difference was found in the cognitive score comparing sevoflurane and desflurane groups, except for memory tasks where the sevoflurane group performed worse (p = 0.01).The age or the duration of anaesthesia did not affect postoperative scores. Postoperative satisfaction negatively correlated with the memory score (r = -0.35, p = 0.03). Postoperative satisfaction correlated with the reasoning score (r = -0.55; p < 0.01) and the total score (r = -0.42; p = 0.03) in the sevoflurane group. Likewise, temperature in the sevoflurane group correlated with the memory score (r = -0.58; p = 0.02).

Conclusions

The desflurane group performs better in memory tasks, but no such advantage is found in the total cognitive score. In contrast to the age or anaesthesia duration, intraoperative temperature and postoperative satisfaction may affect postoperative cognitive performance.

Desflurane impairs hippocampal learning on day 1 of exposure: a prospective laboratory study in rats

Background

Quick and complete recovery of cognitive function after general anesthesia is desirable, particularly for working-age patients. Desflurane is less likely to have long-term effects than older-generation inhalational anesthetics, however, its short-term effects have not been fully investigated. Our objective was to elucidate the short-term effects of desflurane exposure on learning and memory in young adult rats.

Methods

Seven-week old male Sprague–Dawley rats were exposed to air (control), or desflurane at 0.7 or 1.2 minimum alveolar concentration (MAC) for 2 h (day 0). The inhibitory avoidance (IA) test was performed on day 1 to delineate the effects on contextual learning. Separate groups of control and 1.2 MAC desflurane animals underwent the IA test on days 3 and 7 to examine the time-dependent changes. Because the IA test is known to be dependent on the long-term potentiation (LTP) of the hippocampus and the trafficking of the GluR1 subunit of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor into the synapses, the effects of 1.2 MAC desflurane on these phenomena were evaluated on day 1.

Results

Desflurane at 1.2 MAC, but not 0.7 MAC, significantly decreased the IA latencies on day 1 compared with the control (one-way ANOVA, F [2,48] = 5.974, P = 0.005, post hoc Tukey’s, mean difference [95% confidence interval], control vs. 1.2 MAC, 168 [49.9 to 287], P = 0.004; control vs. 0.7 MAC, 67.5 [− 51.2 to 186], P = 0.362). The latencies were not affected on days 3 and 7 (day 3, control vs. desflurane, P = 0.861; day 7, control vs. desflurane, P > 0.999). Consistently, hippocampal LTP on day 1 was significantly suppressed in the desflurane group compared with the control group (P = 0.006). Moreover, immunoblotting analysis of synaptic GluR1 expression revealed that desflurane exposure significantly suppressed GluR1 delivery to the synapses after IA training.

Conclusion

Exposure to a relatively high concentration of desflurane caused reversible learning and memory impairment in young adult rats associated with suppression of GluR1 delivery to the synapses in the hippocampus.

Emergence times and airway reactions during general anaesthesia with remifentanil and a laryngeal mask airway: A multicentre randomised controlled trial

BACKGROUND

Avoidance of airway complications and rapid emergence from anaesthesia are indispensable for the use of a laryngeal mask airway (LMA). Evidence from adequately powered randomised studies with a low risk of bias for the optimal anaesthetic in this context is limited.

OBJECTIVE

We tested the hypothesis that when using remifentanil-based intra-operative analgesia, desflurane would be the most suitable anaesthetic: with noninferiority in the occurrence of upper airway complications and superiority in emergence times compared with sevoflurane or propofol.

DESIGN

A randomised, multicentre, partially double-blinded, three-arm, parallel-group study.

SETTING

Two university and two regional German hospitals, from February to October 2015.

PATIENTS

A total of 352 patients (age 18 to 75 years, ASA physical status I to III, BMI less than 35 kg m⁻² and fluent in German) were enrolled in this study. All surgery was elective with a duration of 0.5 to 2 h, and general anaesthesia with a LMA was feasible.

INTERVENTION

The patients were randomised to receive desflurane, sevoflurane or propofol anaesthesia.

MAIN OUTCOME MEASURES

This study was powered for the primary outcome ‘time to state date of birth’ and the secondary outcome ‘intra-operative cough’. Time to emergence from anaesthesia and the incidence of upper airway complications were assessed on the day of surgery.

RESULTS

The primary outcome was analysed for 343 patients: desflurane (n=114), sevoflurane (n=111) and propofol (n=118). The desflurane group had the fastest emergence. The mean (± SD) times to state the date of birth following desflurane, sevoflurane and propofol were 8.1 ± 3.6, 10.1 ± 4.0 and 9.8 ± 5.1 min, respectively (P < 0.01). There was no difference in upper airway complications (cough and laryngospasm) across the groups, but these complications were less frequent than in previous studies.

CONCLUSION

When using a remifentanil infusion for intra-operative analgesia in association with a LMA, desflurane was associated with a significantly faster emergence and noninferiority in the incidence of intra-operative cough than either sevoflurane or Propofol.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02322502; EudraCT identifier: 2014-003810-96.

Influence of intraoperative sevoflurane or desflurane on postoperative sore throat: a prospective randomized study

PURPOSE

Tracheal intubation for general anesthesia causes postoperative sore throat. The purpose of this study was to evaluate the effect of sevoflurane and desflurane on prevalence of postoperative sore throat in patients after general anesthesia.

METHODS

Ninety-six patients scheduled for orthopedic lower extremity surgery under general anesthesia were assigned to sevoflurane group or desflurane group. In the sevoflurane group (n = 48), sevoflurane was used as a maintenance anesthetic agent. In the desflurane group (n = 48), desflurane was used. Prevalence of sore throat, number of patients with rescue analgesics, and analgesics requirements were evaluated.

RESULTS

The overall prevalence of postoperative sore throat in the sevoflurane group was lower than that in the desflurane group [21 (44%) vs. 32 (67%), p = 0.024]. The prevalence of sore throat at postoperative 4 h in the sevoflurane group was lower than that in the desflurane group [6 (13%) vs. 18 (38%), p = 0.005]. The number of patients requiring rescue analgesics was lower in the sevoflurane group [25 (52%) vs. 36 (75%), p = 0.020]. The requirement of diclofenac was also lower in the sevoflurane group (30 ± 37 mg vs. 47 ± 40 mg, p = 0.031).

CONCLUSIONS

We have shown that sevoflurane was associated with less frequent sore throat than desflurane in patients undergoing orthopedic lower extremity surgery.

The effect of bispectral index monitoring on cognitive performance following sedation for outpatient colonoscopy: a randomized controlled trial

BACKGROUND

Bispectral index (BIS) monitoring can positively affect cognitive performance through decreasing the use of sedative agents. We aimed to evaluate the effect of BIS monitoring on early cognitive performance among patients undergoing sedation for colonoscopy.

DESIGN AND SETTING

Randomized, controlled trial in a university hospital.

METHODS

100 patients were randomized into two groups. In the monitored group (n = 50), the depth of anesthesia was monitored using the BIS, and BIS scores were maintained between 60 and 80. In the usual care group (n = 50), BIS monitoring was not performed. To determine the patients' baseline cognitive performance levels, the mini-mental state examination (MMSE), Trieger dot test (TDT) and clock drawing test (CDT) were used. The patients' post-procedure cognitive performance levels were determined when they were classified as ready for discharge.

RESULTS

The total volume (mg) of propofol used [median (range) IQR] in the sedation procedure was lower in the monitored group [100 (50-200) 100-140] than in the usual care group [150 (75-200) 100-200] (P < 0.001). The discharge scores [mean (SD)] using MMSE and CDT were higher in the monitored group [26 (3) and 3 (1), respectively] than in the usual care group [23 (3) and 2 (1), respectively] (P = 0.002 and P = 0.002, respectively). The discharge scores using TDT [mean (SD)] were lower in the monitored group [11 (7)] than in the usual care group [15 (11)] (P = 0.033).

CONCLUSION

BIS monitoring among sedated patients was associated with lower propofol use and smaller decline in cognitive performance.

CLINICAL TRIAL REGISTRATION

This trial was registered in the Australian New Zealand Clinical Trial Registry (ACTRN12617000134325).

Postoperative cognitive dysfunction and short-term neuroprotection from blueberries: a pilot study

BACKGROUND

General anesthesia may be a risk factor for post-operative cognitive impairment, which could be counteracted by neuroprotective compounds. The aims of this study were to determine cognitive functions impaired by general anesthesia and to test blueberry juice as a neuroprotective agent against neuropsychological dysfunctions induced by general anesthesia.

METHODS

Twenty-six patients undergoing elective major surgery were randomized into two groups, receiving either 500 mL/day of blueberry juice within 14 preoperative days (G1) or to a control group (G0). Neuropsychological tests were performed around 20 days before surgery (T0), as well as both three hours (T1) and 24 hours (T2) after surgery. All the scores were statistically analyzed to find significant differences between groups and within the three times.

RESULTS

The control (G0) group showed a significant decrease in the performance in the Prose Memory Test (P<0.001), the Attentional Matrices Test (P<0.01), and the Trail Making Test Part B (P<0.01) after general anesthesia. Significant differences were reported in the Prose Memory test, T0 versus T1 (P<0.01), T0 versus T2 (P<0.001); in the Trail Making Test Part B, T0 versus T2 (P<0.01); and the Attentional Matrices test, and T0 versus T2 (P<0.001). The G1 group did not show any decrease in the performance of the three tests.

CONCLUSIONS

General anesthesia induces a short-term impairment of verbal memory and selective and divided attention. Blueberry compounds may prevent these neuropsychological deficits through a neuroprotective action in patients undergoing general anesthesia.

A prospective randomized study comparing recovery following anesthesia with a combination of intravenous dexmedetomidine and desflurane or sevoflurane in spinal surgeries

Background and Aims:

Desflurane and sevoflurane are inhalational anesthetics which provide stable intraoperative hemodynamics and rapid emergence from anesthesia. Dexmedetomidine is an α2-agonist with sedative and hypnotic effects. We compared recovery following anesthesia with a combination of a continuous intravenous infusion of dexmedetomidine and desflurane or sevoflurane in cases of spine surgeries because no such data are available from India.

Material and Methods:

It was a single-blind, prospective, randomized study. After institutional ethics committee approval, patients were randomly allocated to one of the two groups of fifty patients each. Group D received desflurane and Group S received sevoflurane, along with dexmedetomidine 0.5 μg/kg/h IV infusion for maintenance of anesthesia.

Results and Conclusions:

Extubation time (ET) in Group D was shorter by 4.2 min than in Group S (10.1 ± 2.2 and 14.2 ± 1.3; P = 0.004). Postoperative recovery, postoperative analgesic, and antiemetic requirement between the groups were comparable The mean dial setting required to maintain the minimum alveolar concentration of 1 intraoperatively was 3.1 for desflurane and 0.7 for sevoflurane.

Effect of sugammadex versus neostigmine/atropine combination on postoperative cognitive dysfunction after elective surgery

This study aimed to assess the effects of sugammadex and neostigmine/atropine on postoperative cognitive dysfunction (POCD) in adult patients after elective surgery. A randomised, double-blind controlled trial was carried out on 160 American Society of Anesthesiologists physical status I to III patients who were >40 years. The Mini-Mental State Evaluation, clock-drawing test and the Isaacs Set test were used to assess cognitive function at three timepoints: 1) preoperatively, 2) one hour postoperatively, and 3) at discharge. The anaesthetic protocol was the same for all patients, except for the neuromuscular block reversal, which was administered by random allocation using either sugammadex or neostigmine/atropine after the reappearance of T2 in the train-of-four sequence. POCD was defined as a decline ≥1 standard deviation in ≥2 cognitive tests. The incidence of POCD was similar in both groups at one hour postoperatively and at discharge (28% and 10%, in the neostigmine group, 23% and 5.4% in the sugammadex group, P=0.55 and 0.27 respectively). In relation to individual tests, a significant decline of clock-drawing test in the neostigmine group was observed at one hour postoperatively and at discharge. For the Isaacs Set test, a greater decline was found in the sugammadex group. These findings suggest that there are no clinically important differences in the incidence of POCD after neostigmine or sugammadex administration.

Postoperative Cognitive Dysfunction in the Elderly: A Review Comparing the Effects of Desflurane and Sevflurane

PURPOSE

The incidence of postoperative cognitive dysfunction (POCD) remains a relatively common complication in the elderly following surgery. Use of anesthesia for surgery might precipitate certain cognitive alterations. The purpose of this review is to address the impact of two volatile anesthetic agents, desflurane and sevoflurane, on POCD.

DESIGN

The focus of this review was on postoperative recovery and complications using two anesthetic agents.

METHODS

Several databases including PubMed and Cochrane were searched from the date of inception. The search words POCD, elderly, general anesthetics, desflurane, and sevoflurane were used and the search was limited to human, randomized clinical trials, and English.

FINDINGS

The findings show no difference in the emergence time between sevoflurane and desflurane and the incidence of POCD.

CONCLUSIONS

No definitive conclusion can be drawn about the type of anesthetic used and its relation to occurrence of POCD. However, the information presented is crucial, which can help to improve anesthetic usage and patient safety.

A clinical review of inhalation anesthesia with sevoflurane: from early research to emerging topics

A large number of studies during the past two decades have demonstrated the efficacy and safety of sevoflurane across patient populations. Clinical researchers have also investigated the effects of sevoflurane, its hemodynamic characteristics, its potential protective effects on several organ systems, and the incidence of delirium and cognitive deficiency. This review examines the clinical profiles of sevoflurane and other anesthetic agents, and focuses upon emerging topics such as organ protection, postoperative cognitive deficiency and delirium, and novel ways to improve postanesthesia outcomes.

Effects of midazolam or tramadol premedication on early cognitive function in endoscopic retrograde cholangiopancreatography (ERCP): A randomized, controlled, double-blind study

OBJECTIVE

To evaluate the sedative efficacy and effects on early period cognitive function of premedication in endoscopic retrograde cholangiopancreatography (ERCP).

METHODS

Forty patients (18-70 years; American Society of Anesthesiology risk category I-III) undergoing elective ERCP were randomized to receive oral premedication with 0.15 mg/kg midazolam or 1 mg/kg tramadol. Cognitive function was determined by mini-mental test (MMT). Target scores for effective sedation were determined as a Bispectral index score of 70-90 and modified Ramsay Sedation Scale score (mRSS) of 2-4.

RESULTS

Global MMT score was not significantly different between treatment groups at 60 min post-ERCP. A significant deterioration in the MMT subcategory of recall was determined in with midazolam versus tramadol. Level of sedation (mRSS) was higher in with midazolam compared with tramadol reaching statistical significance at 30 min after drug administration.

CONCLUSIONS

Although more effective sedation was obtained with midazolam in patients undergoing ERCP, there was a dysfunction in memory recall. It was concluded, however, that early cognitive functions were generally preserved with both drugs.

Anaesthesia for hip fracture surgery in adults

BACKGROUND

The majority of people with hip fracture are treated surgically, requiring anaesthesia.

OBJECTIVES

The main focus of this review is the comparison of regional versus general anaesthesia for hip (proximal femoral) fracture repair in adults. We did not consider supplementary regional blocks in this review as they have been studied in another review.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library; 2014, Issue 3), MEDLINE (Ovid SP, 2003 to March 2014) and EMBASE (Ovid SP, 2003 to March 2014).

SELECTION CRITERIA

We included randomized trials comparing different methods of anaesthesia for hip fracture surgery in adults. The primary focus of this review was the comparison of regional anaesthesia versus general anaesthesia. The use of nerve blocks preoperatively or in conjunction with general anaesthesia is evaluated in another review. The main outcomes were mortality, pneumonia, myocardial infarction, cerebrovascular accident, acute confusional state, deep vein thrombosis and return of patient to their own home.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. We analysed data with fixed-effect (I(2) < 25%) or random-effects models. We assessed the quality of the evidence according to the criteria developed by the GRADE working group.

MAIN RESULTS

In total, we included 31 studies (with 3231 participants) in our review. Of those 31 studies, 28 (2976 participants) provided data for the meta-analyses. For the 28 studies, 24 were used for the comparison of neuraxial block versus general anaesthesia. Based on 11 studies that included 2152 participants, we did not find a difference between the two anaesthetic techniques for mortality at one month: risk ratio (RR) 0.78, 95% confidence interval (CI) 0.57 to 1.06; I(2) = 24% (fixed-effect model). Based on six studies that included 761 participants, we did not find a difference in the risk of pneumonia: RR 0.77, 95% CI 0.45 to 1.31; I(2) = 0%. Based on four studies that included 559 participants, we did not find a difference in the risk of myocardial infarction: RR 0.89, 95% CI 0.22 to 3.65; I(2) = 0%. Based on six studies that included 729 participants, we did not find a difference in the risk of cerebrovascular accident: RR 1.48, 95% CI 0.46 to 4.83; I(2) = 0%. Based on six studies that included 624 participants, we did not find a difference in the risk of acute confusional state: RR 0.85, 95% CI 0.51 to 1.40; I(2) = 49%. Based on laboratory tests, the risk of deep vein thrombosis was decreased when no specific precautions or just early mobilization was used: RR 0.57, 95% CI 0.41 to 0.78; I(2) = 0%; (number needed to treat for an additional beneficial outcome (NNTB) = 3, 95% CI 2 to 7, based on a basal risk of 76%) but not when low molecular weight heparin was administered: RR 0.98, 95% CI 0.52 to 1.84; I(2) for heterogeneity between the two subgroups = 58%. For neuraxial blocks compared to general anaesthesia, we rated the quality of evidence as very low for mortality (at 0 to 30 days), pneumonia, myocardial infarction, cerebrovascular accident, acute confusional state, decreased rate of deep venous thrombosis in the absence of potent thromboprophylaxis, and return of patient to their own home. The number of studies comparing other anaesthetic techniques was limited.

AUTHORS' CONCLUSIONS

We did not find a difference between the two techniques, except for deep venous thrombosis in the absence of potent thromboprophylaxis. The studies included a wide variety of clinical practices. The number of participants included in the review is insufficient to eliminate a difference between the two techniques in the majority of outcomes studied. Therefore, large randomized trials reflecting actual clinical practice are required before drawing final conclusions.

Changes in cerebral oxygen saturation and early postoperative cognitive function after laparoscopic gastrectomy: a comparison with conventional open surgery

BACKGROUND

Laparoscopic gastrectomy requires a reverse-Trendelenburg position and prolonged pneumoperitoneum and it could cause significant changes in cerebral homeostasis and lead to cognitive dysfunction. We compared changes in regional cerebral oxygen saturation (rSO2), early postoperative cognitive function and hemodynamic variables in patients undergoing laparoscopic gastrectomy with those patients that underwent conventional open gastrectomy.

METHODS

Sixty patients were enrolled in this study and the patients were distributed to receive either laparoscopic gastrectomy (laparoscopy group, n = 30) or open conventional gastrectomy (open group, n = 30). rSO2, end-tidal carbon dioxide tension, hemodynamic variables and arterial blood gas analysis were monitored during the operation. The enrolled patients underwent the mini-mental state examination 1 day before and 5 days after surgery for evaluation of early postoperative cognitive function.

RESULTS

Compared to baseline value, rSO2 and end-tidal carbon dioxide tension increased significantly in the laparoscopy group after pneumoperitoneum, whereas no change was observed in the open group. No patient experienced cerebral oxygen desaturation or postoperative cognitive dysfunction. Changes in mean arterial pressure over time were significantly different between the groups (P < 0.001).

CONCLUSIONS

Both laparoscopic and open gastrectomy did not induce cerebral desaturation or early postoperative cognitive dysfunction in patients under desflurane anesthesia. However, rSO2 values during surgery favoured laparoscopic surgery, which was possibly related to increased cerebral blood flow due to increased carbon dioxide tension and the effect of a reverse Trendelenburg position.

Perioperative Cognitive Protection-Cognitive Exercise and Cognitive Reserve (The Neurobics Trial): A Single-blind Randomized Trial

PURPOSE

The Neurobics Trial is a single-blind, parallel-group, randomized, controlled trial. The main study objective is to compare effectiveness of preoperative cognitive exercise versus no intervention for lowering the incidence of postoperative delirium. Enrollment began March 2015 and is ongoing.

METHODS

Eligible participants include patients older than 60 years of age scheduled for nonemergent, noncardiac, nonneurological surgery at our institution. Patients provide consent and are screened at our Outpatient Preoperative Assessment Clinic to rule out preexisting cognitive dysfunction, significant mental health disorders, and history of surgery requiring general anesthesia in the preceding 6 months. Participants meeting criteria are randomized to complete 1 hour daily of electronic tablet-based cognitive exercise for 10 days before surgery or no preoperative intervention. Compliance with the effective dose of 10 total hours of preoperative exercise is verified on return of the patient for surgery with time logs created by the software application and by patient self-reporting. After surgery, patients are evaluated for delirium in the postanesthesia recovery area, and then twice daily for the remainder of their hospitalization. Additionally, postoperative quality of recovery is assessed daily, along with pain scores and opiate use. More comprehensive cognitive assessments are completed just before discharge for baseline comparison, and quality of recovery is assessed via telephone interview 7, 30, and 90 days post-surgery. The primary outcome is the incidence of delirium during the postoperative hospitalization period. Randomization is computer generated, with allocation concealment in opaque envelopes. All postoperative assessments are completed by blinded study personnel.

FINDINGS

The study is actively recruiting with 19 patients having provided consent to date, and a total of 264 patients is required for study completion; therefore, no data analysis is currently under way (www.clinicaltrials.gov; NCT02230605).

IMPLICATIONS

To our knowledge, the Neurobics Trial is the first randomized, controlled study to investigate the effectiveness of a significant preoperative cognitive exercise regimen for the prevention of delirium after noncardiac, nonneurological surgery in elderly patients.

Effects of changing from sevoflurane to desflurane on the recovery profile after sevoflurane induction: a randomized controlled study

PURPOSE

Desflurane has the lowest solubility of currently available volatile anesthetics and may allow for more rapid emergence and recovery compared with sevoflurane. Nevertheless, after volatile induction with sevoflurane, it has not been determined whether the use of desflurane provides faster emergence and recovery. The present study aimed to elucidate the effects of changing from sevoflurane to desflurane during the early part of anesthesia.

METHODS

Fifty-two patients who were scheduled for vitreous surgery with general anesthesia were enrolled in this randomized controlled study. Anesthesia was induced with volatile induction consisting of 100% oxygen (6 L·min(-1)) and 5% sevoflurane. For anesthesia maintenance, patients were randomized to receive 1-2% sevoflurane or 3-6% desflurane. In the desflurane group, the anesthetic agent was changed from sevoflurane to desflurane within five minutes following endotracheal intubation. After surgery, we assessed the following endpoints: the times from discontinuing volatile anesthetics to eye opening, obeying the command to squeeze the investigator's hand, tracheal extubation, and orientation to the patients' full name, date, and place.

RESULTS

Emergence and recovery were significantly faster in the desflurane group than in the sevoflurane group in times to mean (SD) eye opening [6.5 (2.9) vs 10.1(3.0) min, respectively; mean difference, 3.6 min; 95% confidence interval (CI), 1.9 to 5.3; P < 0.001], obeying commands [6.6 (2.7) vs 10.1 (3.1) min, respectively; mean difference, 3.5 min; 95% CI, 1.9 to 5.2; P < 0.001], and tracheal extubation [7.0 (2.5) vs 10.6 (3.0) min, respectively; mean difference, 3.6 min; 95% CI, 1.9 to 5.1; P < 0.001]. Similarly, the times from discontinuation of volatile anesthetics to orientation to the patients' full name, date, and place were significantly shorter in the desflurane group compared with the sevoflurane group. There were no significant differences between groups on a 100-mm visual analogue scale assessing postoperative nausea and vomiting, eye pain, and patient satisfaction regarding anesthesia.

CONCLUSION

Changing the anesthetic agent from sevoflurane to desflurane after sevoflurane induction provides faster emergence and recovery compared with sevoflurane anesthesia. This study protocol was registered at http://www.umin.ac.jp/ctr/index.htm , (UMIN000009941).

Influence of Ketamine on Early Postoperative Cognitive Function After Orthopedic Surgery in Elderly Patients

Background:

Postoperative cognitive dysfunction (POCD) is a serious and frequent complication after surgery, especially in elderly patients. Ketamine is an N-methyl D-aspartic acid receptor antagonist with demonstrated neuroprotective effects. An intravenous bolus of a sub-anesthetic dose (0.5 mg/kg) of ketamine can reduce postoperative delirium (POD) and POCD after cardiac surgery. But, the influence of ketamine on early POCD after non-cardiac surgery is unclear.

Objectives:

The current study aimed to evaluate the influence of ketamine on early postoperative cognitive function after orthopedic surgery in elderly patients.

Patients and Methods:

Fifty six elderly patients (> 60-years-old), scheduled for elective orthopedic surgery during general anesthesia (duration of anesthesia > two hours) were enrolled. Patients received intravenous bolus, a total of 3 mL mixed with 0.9% normal saline and 0.5 mg/kg ketamine (K group) or 3 mL of 0.9% normal saline (N group). Three neurocognitive function tests (mini-mental status examination, trail-making test, digit substitution test), and c-reactive protein (CRP) concentration were determined before surgery and on postoperative day one (POD 1) and postoperative day six (POD 6).

Results:

The two groups had similar demographic characteristics except for the gender. Surgical and anesthetic data were not significantly different. A statistically significant difference was observed in comparison of trail-making test score. Trail-making test score increased more in the N group (52.5 points) than the K group (13 points) at POD 1 (P = 0.047) compared with baseline scores. There were no significant differences in the mini-mental status examination, digit substitution test and CRP concentration at POD 1 and POD 6 between the two groups. POCD (the two Z-scores in more than two tests or the combined Z-score was 1.96 or more) was present in one patient (4%) in the K group at POD 6 (P = 0.98).

Conclusions:

The incidence of POCD was not significantly influenced by a bolus dose of ketamine (0.5 mg/kg) after orthopedic surgery in elderly patients. There were no negative effects of ketamine on early POCD.

Comparison of early recovery and cognitive function after desflurane and sevoflurane anaesthesia in elderly patients: A meta-analysis of randomized controlled trials

Objectives

A meta-analysis to compare postoperative cognitive function and the time to specific recovery events in elderly patients (aged >65 years) anaesthetized with sevoflurane or desflurane.

Methods

A systematic search of the PubMed®, Embase®, Cochrane Library and Chinese Biomedical databases was performed using the keywords ‘sevoflurane’ and ‘desflurane’. Data and characteristics of appropriate randomized controlled trials (RCTs) were extracted.

Results

The meta-analysis included five trials ( n = 300). The time taken to follow commands (mean difference [MD] −3.27; 95% confidence intervals [CI] −4.95, −1.59), extubation (MD −1.59; 95%CI −2.62, −0.55), orientation (MD −4.31; 95%CI −4.99, −3.62), and recovery room discharge (MD −9.38; 95%CI −13.43, −5.42) were significantly shorter in the desflurane group than in the sevoflurane group. There was no significant between-drug difference in the incidence of postoperative cognitive dysfunction or the time taken to open the eyes.

Conclusions

Desflurane is associated with a faster recovery from general anaesthesia than sevoflurane in elderly patients.

Postoperative Cognitive Dysfunction: Minding the Gaps in Our Knowledge of a Common Postoperative Complication in the Elderly

Postoperative cognitive dysfunction (POCD) is a common complication associated with significant morbidity and mortality in elderly patients. There is much interest in and controversy about POCD, reflected partly in the increasing number of articles published on POCD recently. Recent work suggests surgery may also be associated with cognitive improvement in some patients, termed postoperative cognitive improvement (POCI). As the number of surgeries performed worldwide approaches 250 million per year, optimizing postoperative cognitive function and preventing/treating POCD are major public health issues. In this article, we review the literature on POCD and POCI, and discuss current research challenges in this area.

Comparison of intraoperative brain condition, hemodynamics and postoperative recovery between desflurane and sevoflurane in patients undergoing supratentorial craniotomy

Background:

Post operative recovery has been reported to be faster with desflurane than sevoflurane anesthesia in previous studies. The use of desflurane is often criticized in neurosurgery due to the concerns of cerebral vasodilation and increase in ICP and studies comparing desflurane and sevoflurane in neurosurgey are scarce. So we compared the intraoperative brain condition, hemodynamics and postoperative recovery in patients undergoing elective supratentorial craniotomy receiving either desflurane or sevoflurane.

Materials and Methods:

Fifty three patients between 18-60yr undergoing elective supratentorial craniotomy receiving N₂O and oxygen (60%:40%) and 0.8-1.2 MAC of either desflurane or sevoflurane were randomized to group S (Sevoflurane) or group D (Desflurane). Subdural intra cranial pressure (ICP) was measured and brain condition was assessed.. Emergence time, tracheal extubation time and recovery time were recorded. Cognitive behavior was evaluated with Short Orientation Memory Concentration Test (SOMCT) and neurological outcome (at the time of discharge) was assessed using Glasgow Outcome Score (GOS) between the two groups.

Results:

The emergence time [Group D 7.4 ± 2.7 minutes vs. Group S 7.8 ± 3.7 minutes; P = 0.65], extubation time [Group D 11.8 ± 2.8 minutes vs. Group S 12.9 ± 4.9 minutes; P = 0.28] and recovery time [Group D 16.4 ± 2.6 minutes vs. Group S 17.1 ± 4.8 minutes; P = 0.50] were comparable between the two groups. There was no difference in ICP [Group D; 9.1 ± 4.3 mmHg vs. Group S; 10.9 ± 4.2 mmHg; P = 0.14] and brain condition between the two groups. Both groups had similar post-operative complications, hospital and ICU stay and GOS.

Conclusion:

In patients undergoing elective supratentorial craniotomy both sevoflurane and desflurane had similar intra-operative brain condition, hemodynamics and post operative recovery profile.

Recovery following desflurane versus sevoflurane anesthesia for outpatient urologic surgery in elderly females

Background:

An unresolved question is the time required for the ability to return to complex tasks following anesthesia.

Objectives:

This study aims to characterize the severity and duration of cognitive impairment following sevoflurane or desfluane anesthesia after brief surgery using tests of cognitive ability to objectively testing performance.

Patients and Methods:

This study is a double blinded randomized controlled trial. Patients were randomized to receive either a desflurane or sevoflurane-based anesthetic. On the morning of the surgery the subjects performed baseline cognitive task tests (Mini Mental Status exam, Trail Making Test Part A and B, Digit Symbol Coding, Hopkins Verbal Learning Test, Stroop Color and Word Test to determine baseline cognitive function. Cognitive testing was repeated 30 minutes and 1 hour after surgery whereas Modified Telephone Interview for Cognitive Status (TICS-M) and Memory Aging Telephone Screen (MATS) was used on the following day of surgery.

Results:

Trail Making Test Part B cognitive test showed statistically significant in comparison for pre and post exposure of anesthetics. This difference was seen in the desflurane group. Other cognitive tests did not show differences on exposure to the anesthetic gases.

Conclusions:

This study questioned the difference between volatile anesthetic agent’s effects on patients completing a battery of neurocognitive tests attempting to answer if one agent has a more profound effect. Our study shows no statistically significant cognitive decline except for those in the Trail Making Part B in the Desflurane group. This conclusion is limited by the inherent limitations of the study, but does reinforce that the systemic inflammatory response from the surgery contributes cognitive impairment.

Perioperative management of elderly patients

The older population only represents 13.7% of the US population but has grown by 21% since 2002. The centenarian population is growing at a faster rate than the total US population. This unprecedented growth has significantly increased surgical demand. The establishment of quality and performance improvement data has allowed researchers to focus attention on the older patient population, resulting in an exponential increase in studies. Although there is still much work to be done in this field, overlying themes regarding the perioperative management of elderly patients are presented in this article based on a thorough literature review.

Effect of inhalational anaesthetic on postoperative cognitive dysfunction following radical rectal resection in elderly patients with mild cognitive impairment

Aims

To determine the effect of choice of inhalational anaesthetic (sevoflurane vs propofol) on the incidence and severity of postoperative cognitive dysfunction (POCD) in elderly patients (aged ≥ 60 years) with mild cognitive impairment (MCI).

Methods

Elderly patients with MCI undergoing radical rectal resection were randomly assigned to receive sevoflurane or propofol general anaesthesia. Cognitive function was assessed using neuropsychological testing before and 7 days after surgery. POCD severity was graded as mild, moderate or severe using standard deviation cut-offs.

Results

At 7 days after surgery, the incidence of POCD was 29.7% in the propofol group ( n = 101) and 33.3% in the sevoflurane group ( n = 99). There was a significant between-group difference for POCD severity: sevoflurane anaesthesia had a more severe impact on cognitive function than propofol anaesthesia.

Conclusions

There was no difference in the incidence of POCD at 7 days after radical rectal resection under sevoflurane or propofol-based general anaesthesia. Both propofol and sevoflurane were associated with negative cognitive effects, but sevoflurane had a more severe impact on cognitive function than propofol, in elderly patients with MCI.

General anesthetic and the risk of dementia in elderly patients: current insights

In this review, we aim to provide clinical insights into the relationship between surgery, general anesthesia (GA), and dementia, particularly Alzheimer’s disease (AD). The pathogenesis of AD is complex, involving specific disease-linked proteins (amyloid-beta [Aβ] and tau), inflammation, and neurotransmitter dysregulation. Many points in this complex pathogenesis can potentially be influenced by both surgery and anesthetics. It has been demonstrated in some in vitro, animal, and human studies that some anesthetics are associated with increased aggregation and oligomerization of Aβ peptide and enhanced accumulation and hyperphosphorylation of tau protein. Two neurocognitive syndromes that have been studied in relation to surgery and anesthesia are postoperative delirium and postoperative cognitive dysfunction, both of which occur more commonly in older adults after surgery and anesthesia. Neither the route of anesthesia nor the type of anesthetic appears to be significantly associated with the development of postoperative delirium or postoperative cognitive dysfunction. A meta-analysis of case-control studies found no association between prior exposure to surgery utilizing GA and incident AD (pooled odds ratio =1.05, P=0.43). The few cohort studies on this topic have shown varying associations between surgery, GA, and AD, with one showing an increased risk, and another demonstrating a decreased risk. A recent randomized trial has shown that patients who received sevoflurane during spinal surgery were more likely to have progression of preexisting mild cognitive impairment compared to controls and to patients who received propofol or epidural anesthesia. Given the inconsistent evidence on the association between surgery, anesthetic type, and AD, well-designed and adequately powered studies with longer follow-up periods are required to establish a clear causal association between surgery, GA, and AD.

Plasma kynurenic acid concentration in patients undergoing cardiac surgery: effect of anaesthesia

Increases in plasma kynurenic acid (KYNA) concentration relate to the severity of inflammation. The aim of this study was to analyse changes in plasma KYNA concentration and neutrophil/lymphocyte ratio (NLR) in cardiac surgery patients. Additionally, the effect of anaesthesia was analysed. Adult cardiac surgery patients under intravenous general anaesthesia were studied. Additionally, some patients received sevoflurane (SEV) prior to cardiopulmonary bypass. Plasma KYNA concentration and NLR were measured before anaesthesia, just after surgery and on postoperative days 1, 2 and 3. Patients were assigned to two groups: patients who did not receive SEV (NonSEV group) and patients who received SEV (SEV group). Forty-three patients were studied. Twenty-four of them received SEV. KYNA increased immediately after surgery and remained elevated through postoperative day 3 in the NonSEV group, whereas it was similar to the preoperative concentration in the SEV group. NLR increased immediately after surgery in both groups, and higher values were noted in the NonSEV group than in the SEV group at postoperative days 2 and 3. Plasma KYNA concentration correlated with NLR in the NonSEV group. Cardiac surgery caused an increase in NLR. Plasma KYNA increased in the NonSEV group and correlated with NLR. Administration of SEV inhibited the increase in KYNA, most likely due to its anti-inflammatory properties.

Cognitive dysfunction following desflurane versus sevoflurane general anesthesia in elderly patients: a randomized controlled trial

As life expectancy increases, more patients ≥65 years undergo general anesthesia. Anesthetic agents may contribute to postoperative cognitive dysfunction, and incidence may differ with anesthetic agents or intraoperative anesthesia depth. Responses to anesthetic adjuvants vary among elderly patients. Processed electroencephalography guidance of anesthetic may better ensure equivalent cerebral suppression. This study investigates postoperative cognitive dysfunction differences in elderly patients given desflurane or sevoflurane using processed electroencephalography guidance.

IRB approved, randomized trial enrolled consenting patients ≥65 years scheduled for elective surgery requiring general anesthesia ≥120 minute duration. After written informed consent, patients were randomly assigned to sevoflurane or desflurane. No perioperative benzodiazepines were administered. Cognitive impairment was measured by an investigator blinded to group assignment using mini-Mental Status Examination (MMSE) at baseline; 1, 6, and 24 hours after the end of anesthesia. Mean arterial pressure was maintained within 20% of baseline. Anesthetic dose was adjusted to maintain moderate general anesthesia per processed electroencephalograpy (Patient State Index 25 to 50). The primary outcome measure was intergroup difference in MMSE change 1 hour after anesthesia (median; 95% confidence interval).

110 patients consented; 26 were not included for analysis (no general anesthesia; withdrew consent; baseline MMSE abnormality; inability to perform postoperative MMSE; data capture failure); 47 sevoflurane and 37 desflurane were analyzed. There were no significant differences in patient characteristics; intraoperative mean blood pressure (desflurane 86.4; 81.3 to 89.6 versus sevoflurane 82.5; 80.2 to 86.1 mmHg; p = 0.42) or Patient State Index (desflurane 41.9; 39.0 to 44.0 versus sevoflurane 41.0; 37.5 to 44.0; p = 0.60) despite a lower MAC fraction in desflurane (0.82; 0.77 to 0.86) versus sevoflurane (0.96; 0.91 to 1.03; p < 0.001). MMSE decreased 1 hour after anesthesia (p < 0.001). The decrease at one hour was larger in sevoflurane (−2.5; −3.3 to −1.8) than desflurane (−1.3; −2.2 to −0.5; p = 0.03). MMSE returned to baseline by 6 hours after anesthesia.

Emergence in elderly patient undergoing general anesthesia with xenon

Introduction. It is a consensus that the postoperative cognitive function is impaired in elderly patients after general anaesthesia, and such category patient takes more time to recover. Xenon is a noble gas with anesthetic properties mediated by antagonism of N-methyl-D-aspartate receptors. With a minimum alveolar concentration of 0.63, xenon is intended for maintaining hypnosis with 30% oxygen. The fast recovery after xenon anaesthesia was hypothesized to be advantageous in this scenario. Case Presentation. We report the case of 99-year-old woman who underwent sigmoid colon carcinoma resection with colorectal anastomosis. We carried out the induction phase by propofol, oxygen, fentanil, and rocuronium bromide, and then we proceeded to a rapid sequence endotracheal intubation consequently. The patient was monitored by IBP, NIBP, ECG, cardiac frequency, respiratory rate, capnometry, TOF Guard, blood gas analysis, and BIS. For maintenance we administrated oxygen, remifentanil, rocuronium bromide, and xenon gas 60-65%. Shortly after the end of surgery the patients started an autonomous respiratory activity, and a high BIS level was also recorded. Decision was made by our team to proceed into the emergence phase. The residual neuromuscular block was antagonized by sugammadex, modified Aldrete score was implicated, and we got our patient fully awake without any cognitive dysfunction or delirium. Conclusion. The rapid emergence to full orientation in very elderly patient who had been anesthetized by xenon shows concordance to the high BIS values and the clinical signs of the depth of anesthesia.

Differential general anesthetic effects on microglial cytokine expression

Post-operative cognitive dysfunction has been widely observed, especially in older patients. An association of post-operative cognitive dysfunction with the neurodegenerative diseases, such as Alzheimer's disease, has been suggested. Neuroinflammation contributes to Alzheimer pathology, through elevated pro-inflammatory cytokines and microglial activation in the CNS leading to neuronal damage, synaptic disruption and ultimately cognitive dysfunction. We compare the effects of three different, clinically-used, anesthetics on microglial activation with, and without, the prototypical inflammatory trigger, lipopolysaccharide (LPS). Microglial BV-2 cell cultures were first exposed to isoflurane, sevoflurane (each at 2 concentrations) or propofol for 6 h, and cytokine levels measured in lysates and media. The same experiments were repeated after 1 h LPS pre-treatment. We found; 1) anesthetics alone have either no or only a small effect on cytokine expression; 2) LPS provoked a large increase in microglia cytokine expression; 3) the inhaled anesthetics either had no effect on LPS-evoked responses or enhanced it; 4) propofol nearly eliminated the LPS pro-inflammatory cytokine response and improved cell survival as reflected by lactate dehydrogenase release. These data suggest that propofol may be a preferred anesthetic when it is desirable to minimize neuroinflammation.

Postoperative cognitive dysfunction in geriatric patients

Postoperative cognitive dysfunction (POCD) is a severe long-term complication after surgical procedures. POCD is mainly seen among geriatric patients. Hospitalization, extent of surgery, and systemic inflammatory response might contribute to POCD. The possible influence of the type of anesthesia is discussed. POCD is often not recognized; thus, incidence rates are likely to be underestimated (19-40%). POCD is associated with major consequences for the individual patient, e.g., delayed long-term recovery, reduced quality of life, and an increased mortality rate. Multiple risk factors have been identified over the last decade. However, the exact etiology is still unknown. This mini-review summarizes the recent developments concerning POCD prevention, diagnosis, and treatment.

A prospective randomized multicenter comparative study of BLM-240 (desflurane) versus sevoflurane in Japanese patients

The present study was conducted to evaluate the efficacy and safety of BLM-240 (desflurane) in comparison to sevoflurane in Japanese patients. A total of 216 patients were enrolled in this randomized comparative study at 15 medical institutions. The patients received either BLM-240 with 50-70 % N2O in O2 (n = 111), BLM-240 with 30 % O2 in air (n = 55), or sevoflurane with 50-70 % N2O in O2 (n = 50). Efficacy was evaluated by an efficacy rate based on an efficacy evaluation criteria and recovery time to extubation from the discontinuation of the anesthetics. Safety was evaluated by incidence of adverse drug reactions (ADR) and other clinical indicators. The efficacy rate of BLM-240 was 98.8 % (164/166 patients), indicating that BLM-240 is effective as an anesthetic. Time from discontinuation of anesthetic delivery to extubation was 9.7 ± 0.6 min in the BLM-240/N2O group and 14.3 ± 0.9 min in the sevoflurane/N2O group, meeting the pre-defined non-inferiority criteria of BLM-240 to sevoflurane. There was no statistically significant difference in the incidence of total ADR between the BLM-240 group (62.0 %) and sevoflurane group (48.0 %). The results indicate that BLM-240 is an effective and safe inhalation anesthetic in Japanese patients.