A comparative study on adequate anesthesia depth: clinical judgement and the Narcotrend® measurement

Research trends related to emergence agitation in the post-anaesthesia care unit from 2001 to 2023: A bibliometric analysis

Background

Emergence agitation (EA) is a behavioural disturbance encountered during the recovery phase of patients following general anaesthesia. It is characterised by restlessness, involuntary limb movements, and drainage tube withdrawal and may significantly harm patients and medical staff. The mechanism of EA has not been fully understood and is still a challenging subject for researchers.

Methods

We extracted relevant publications published between 1 January 2001 and 31 December 2023 on the Web of Science Core Collection platform. VOSviewer software was utilised to analyse the retrieved literature and predict the development trends and hotspots in the field.

Results

The results show that the number of publications grew annually, with China contributing the most, followed by the United States and South Korea. The co-occurrence of keywords "children," "propofol," "risk factors" are current research hotspots. Owing to its self-limiting and short-duration characteristics, EA lacks standardised clinical time guidelines and objective assessment tools, which may be the focus of future research in this field.

Conclusions

Understanding the research hotspots and the latest progress in this field, this study will help to continuously improve the clinical understanding and management of EA, and help to timely identify environmental risk factors for EA in clinical practice.

Association between postinduction hypotension and postoperative mortality: a single-centre retrospective cohort study

PURPOSE

We aimed to elucidate whether postinduction hypotension (PIH), defined as hypotension between anesthesia induction and skin incision, and intraoperative hypotension (IOH) are associated with postoperative mortality.

METHODS

We conducted a retrospective cohort study of adult patients with an ASA Physical Status I-IV who underwent noncardiac and nonobstetric surgery under general anesthesia between 2015 and 2021 at Nagoya City University Hospital. The primary and secondary outcomes were 30-day and 90-day postoperative mortality, respectively. We calculated four hypotensive indices (with time proportion of the area under the threshold being the primary exposure variable) to evaluate the association between hypotension (defined as a mean blood pressure < 65 mm Hg) and mortality using multivariable logistic regression models. We used propensity score matching and RUSBoost (random under-sampling and boosting), a machine-learning model for imbalanced data, for sensitivity analyses.

RESULTS

Postinduction hypotension and IOH were observed in 82% and 84% of patients, respectively. The 30-day and 90-day postoperative mortality rates were 0.4% (52/14,210) and 1.0% (138/13,334), respectively. Postinduction hypotension was not associated with 30-day mortality (adjusted odds ratio [aOR], 1.03; 95% confidence interval [CI], 0.93 to 1.13; P = 0.60) and 90-day mortality (aOR, 1.01; 95% CI, 0.94 to 1.07; P = 0.82). Conversely, IOH was associated with 30-day mortality (aOR, 1.19; 95% CI, 1.12 to 1.27; P < 0.001) and 90-day mortality (aOR, 1.12; 95% CI, 1.06 to 1.19; P < 0.001). Sensitivity analyses supported the association of IOH but not PIH with postoperative mortality.

CONCLUSION

Despite limitations, including power and residual confounding, postoperative mortality was associated with IOH but not with PIH.

Consciousness and General Anesthesia: Challenges for Measuring the Depth of Anesthesia

The optimal consciousness level required for general anesthesia with surgery is unclear, but in existing practice, anesthetic oblivion, may be incomplete. This article discusses the concept of consciousness, how it is altered by anesthetics, the challenges for assessing consciousness, currently used technologies for assessing anesthesia levels, and future research directions. Wakefulness is marked by a subjective experience of existence (consciousness), perception of input from the body or the environment (connectedness), the ability for volitional responsiveness, and a sense of continuity in time. Anesthetic drugs may selectively impair some of these components without complete extinction of the subjective experience of existence. In agreement with Sanders et al. (2012), the authors propose that a state of disconnected consciousness is the optimal level of anesthesia, as it likely avoids both awareness and the possible dangers of oversedation. However, at present, there are no reliably tested indices that can discriminate between connected consciousness, disconnected consciousness, and complete unconsciousness.

Influence of Narcotrend-Assisted Anesthesia In-Depth Monitor on Cognitive Impairment of Elderly Patients under General Anesthesia

Objective

This research is designed to probe into the influence of Narcotrend- (NT-) assisted anesthesia in-depth monitor on cognitive impairment of elderly patients under general anesthesia (GA).

Methods

One hundred and forty-four elderly patients with GA in our hospital from October 2020 to April 2021 were randomized into two groups, namely, NT group (supervised anesthesia under NT monitoring) and group C (anesthesia according to doctors' experience). The heart rate (HR), mean arterial pressure (MAP), and central venous pressure (CVP) were recorded before surgery (T0), at the beginning of surgery (T1), at the end of surgery (T2), and 1 day after surgery (T3). Serum of patients was obtained at these four time points for measurements of C-reactive protein (CRP), interleukin-6 (IL-6), and cortisol (Cor) levels using the enzyme-linked immunosorbent assay (ELISA). The alterations in cognitive function pre- and post-anesthesia were assessed using the mini-mental state examination (MMSE), and adverse events (AEs) during anesthesia recovery, postoperative recovery, and dosage of anesthetics were recorded.

Results

At T1 and T2, MAP was higher and CVP was lower in NT group, versus group C. NT group presented higher CRP, IL-6, and Cor than group C at T1-T3. MMSE scores were higher in TN group than in group C at 12, 24, and 48 h after surgery. The incidence rates of postoperative cognitive dysfunction (POCD) and total AEs in group C were noticeably higher than those in NT group. Compared with group C, the time of anesthesia recovery, extubation, and postanesthesia care unit (PACU) residence in NT group reduced remarkably.

Conclusions

NT has little effect on the physical condition of elderly patients under GA, and can reduce the dosage of narcotic drugs and promote the recovery of patients from anesthesia, which has high clinical value.

Cerebral Tissue Oxygen Saturation Correlates with Emergence from Propofol-Remifentanil Anesthesia: An Observational Cohort Study

Anesthesia emergence is accompanied by changes in cerebral circulation. It is unknown whether cerebral tissue oxygen saturation (SctO₂) could be an indicator of emergence. Changes in SctO₂, bispectral index (BIS), mean arterial pressure (MAP), and heart rate (HR) were evaluated during the emergence from propofol-remifentanil anesthesia. At the time of cessation of anesthetic delivery, SctO₂, BIS, MAP, and HR values were recorded as baseline. The changes of these parameters from the baseline were recorded as Δ SctO₂, Δ BIS, Δ MAP, and Δ HR. The behavioral signs (body movement, coughing, or eye opening) and response to commands (indicating regaining of consciousness) were used to define emergence states. Prediction probability (Pk) was used to examine the accuracy of SctO₂, BIS, MAP, and HR as indicators of emergence. SctO₂ showed an abrupt and distinctive increase when appearing behavioral signs. BIS, MAP, and HR, also increased but with a large inter-individual variability. Pk value of Δ SctO₂ was 0.97 to predict the appearance behavioral signs from 2 min before that, which was much higher than the Pk values of Δ BIS (0.81), Δ MAP (0.71) and Δ HR (0.87). The regaining of consciousness was associated with a further increase in the SctO₂ value.

Meta-Analysis of the Prognostic Value of Narcotrend Monitoring of Different Depths of Anesthesia and Different Bispectral Index (BIS) Values for Cognitive Dysfunction after Tumor Surgery in Elderly Patients

Objective

To study the effect of Narcotrend monitoring on the incidence of early postoperative cognitive dysfunction (POCD) under different bispectral index (BIS) conditions and the effect of different depths of anesthesia on the incidence of POCD.

Methods

We performed a literature search of PubMed, Embase, OVID (database system made by Ovid Technologies, USA), CBM (Chinese Biomedical Literature database), CNKI (China National Knowledge Infrastructure), Wanfang, and VIP databases (full-text database of Chinese sci-tech journals), etc., from the date of the establishment of the database until December 31, 2020. Our meta-analysis was focused on the collection and study of Narcotrend monitoring of different depths of anesthesia. We carefully read the abstracts and full texts of randomized controlled trials on the incidence of POCD in the early postoperative period, and their references were tracked. Data extraction and quality evaluation of the included literature were also performed, and RevMan 5.3 software was used for analysis.

Results

In the end, eight articles were included, with a total of 714 patients. The meta-analysis results showed that four articles (255 patients) compared the state of deep anesthesia (BIS 30-40) with conventional anesthesia (BIS 40-60 earlier) after POCD. Also, the incidence of POCD on the first day after deep anesthesia (Narcotrend stage (NTS): negative correlation is currently the most appropriate EEG description; Nd can subdivide the original EEG into six stages and 15 levels (Nd Sg, NTS), namely, A (state of wakefulness) state, B0 B2 (sedated state), C0 C2 (light anesthetic state), D0 D2 (general anesthesia), and E0-E1) was significantly lower than that of conventional anesthesia (NTS DO-D1) (odds ratio (OR) = 0.21, 95% confidence interval (CI): 0.13-0.35, P < 0.00001). Moreover, the incidence of POCD in deep anesthesia (NTS E1) at 7 days after surgery was significantly lower than that of conventional anesthesia (NTS D0) (OR (odds ratio) = 0.45, 95% CI: 0.23-0.91, P=0.03), while the incidence of POCD 7 days after NTS D2 in conventional anesthesia was significantly lower than that of NTS D0 (OR = 0.42, 95% CI: 0.24-0.71, P=0.001). Discussion. Deep anesthesia can reduce the incidence of POCD (OR = 0.40, 95% CI: 0.22-0.73, P=0.002). This meta-analysis included three studies (216 patients) that compared the early postoperative POCD incidence of BIS 40-50 under conventional anesthesia and BIS 50-60; the BIS 40-50 did not significantly reduce the incidence of POCD (OR = 1.11, 95% CI: 0.24-5.24, P=0.9). The incidence of POCD under deep anesthesia with Narcotrend monitoring was lower than that under conventional anesthesia.

Systematic review and meta-analysis of the prognostic value of Narcotrend monitoring of different depths of anesthesia and different Bispectral Index (BIS) values for cognitive dysfunction after tumor surgery in elderly patients

Background

To study the effect of Narcotrend monitoring on the incidence of early postoperative cognitive dysfunction (POCD) under different Bispectral Index (BIS) conditions and the effect of different depths of anesthesia on the incidence of POCD.

Methods

We performed a literature search of the PubMed, Embase, OVID (database system made by Ovid Technologies, USA), Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), VIP Chinese Sci-tech Journals Database, Wanfang Data, etc. from the date of establishment of the database until December 31, 2020.

Results

In the end, eighty articles were included, with a total of 714 patients. The meta-analysis results showed that four articles (255 patients) compared the state of deep anesthesia (BIS 30–40) with conventional anesthesia (BIS 40–60 earlier) after POCD. Also, the incidence of POCD on the first day after deep anesthesia [Narcotrend stage (NTS): negative correlation is currently the most appropriate egg description; Nd can subdivide the original electroencephalogram (EEG) into six stages 15 levels (Nd Sg, NTS), or A (state of wakefulness), state B0–B2 (sedated state), state C0–C2 (light anesthetic state), state D0–D2 (general anesthesia), state E0–E2 (deep anesthesia state), and state F0–F2 (burst suppression state)] was significantly lower than that of conventional anesthesia (NTS D0–D1) [odds ratio (OR) =0.21, 95% confidence interval (CI): 0.13–0.35, P<0.00001]. Moreover, the incidence of POCD in deep anesthesia (NTS E1) at 7 days after surgery was significantly lower than that of conventional anesthesia (NTS D0) (OR =0.45, 95% CI: 0.23–0.91, P=0.03), while the incidence of POCD 7 days after NTS D2 in conventional anesthesia was significantly lower than that of NTS D0 (OR =0.42, 95% CI: 0.24–0.71, P=0.001).

Discussions

POCDs are thought to be the result of a combination of physical defects and precipitating factors in patients with their own physical impairments, and despite potential adverse effects, there is currently no consensus on the incidence of POCDs in patients with tumor, current risk factors, causes, and prevention strategies. Moreover, the level of evidence is low, and the deviation between different studies cannot be ruled out.

Comparison of Quantium Consciousness Index and Richmond Agitation Sedation Scale in Mechanically Ventilated Critically Ill Patients: An Observational Study

Background

The quantium consciousness index (qCON), an electroencephalography (EEG)-based modality, has no studies regarding intensive care unit (ICU) sedation, though very few studies describe its use for assessing depth of anesthesia in the operation theater. In this study, we evaluated qCON for assessing sedation compared with Richmond Agitation Sedation Scale (RASS) in patients on a mechanical ventilator in the ICU.

Materials and methods

Eighty-seven mechanically ventilated patients aged between 18 and 60 years were investigated over a 12-hour period. They were given a standardized dosage of sedation comprised of a bolus dose of propofol 0.5 mg/kg and fentanyl 1 µg/kg, and then infusions of propofol 2-5 mg/kg/hour and fentanyl 0.5-2 µg/kg/hour. These drug infusions were adjusted to achieve a RASS score between 0 and -3. Using the qCON monitor, the investigator recorded the qCON values and then assessed the RASS score.

Results

A total of 1,218 readings were obtained. After contrasting each qCON value correspondingly with time to each RASS value, we found their correlation to be statistically significant (ρ = 0.288, p <0.0001). With the help of receiver operating characteristic (ROC) curves, we were able to differentiate appropriate from inappropriate levels of sedation. A qCON value of 80 had a sensitivity of 72.67% and a specificity of 67.42% (AUC 0.738 with SE 0.021).

Conclusion

qCON can be used for assessing sedation levels in mechanically ventilated critically ill patients.

Clinical trial registration

CTRI/2019/07/020064.

How to cite this article

Harsha MS, Bhatia PK, Sharma A, Sethi P. Comparison of Quantium Consciousness Index and Richmond Agitation Sedation Scale in Mechanically Ventilated Critically Ill Patients: An Observational Study. Indian J Crit Care Med 2022;26(4):491-495.