Awareness during emergence from anaesthesia: significance of neuromuscular monitoring in patients with butyrylcholinesterase deficiency

Prolonged duration of action of suxamethonium in pregnant and postpartum patients: A registry study

BACKGROUND

Suxamethonium is hydrolysed by butyrylcholinesterase (BChE) and a low BChE activity can result in a prolonged duration of action of suxamethonium. The BChE activity is reduced during pregnancy and postpartum period by up to 33%. However, it can also be reduced by mutations in the BChE gene. In this study, we assessed BChE activity and mutations in the BChE gene in pregnant and postpartum patients with prolonged duration of action of suxamethonium. It was hypothesised that at least 30% of patients with a low BChE activity did not have a mutation in the BChE gene.

METHODS

In this registry study we focused on pregnant and postpartum patients with a history of prolonged duration of action of suxamethonium referred to the Danish Cholinesterase Research Unit (DCRU) between March 2007 and January 2023. Primary outcome was the proportion of patients without a mutation among patients with a low BChE activity. Secondary outcomes were the proportion of patients with a low BChE activity and the proportion of patients with a mutation out of the total number of patients.

RESULTS

A total of 40 patients were included and among patients with a low BChE activity, 6% (95% CI: 1%-21%) did not have a mutation. Out of the total number of included patients referred to the DCRU, 90% (95% CI: 76%-97%) had a mutation and 94% (95% CI: 80%-99%) had a low BChE activity.

CONCLUSION

Among pregnant and postpartum patients with a history of prolonged duration of action of suxamethonium and a low BChE activity, 6% did not have a mutation in the BChE gene. Our findings suggest that during pregnancy and postpartum clinically relevant prolonged duration of action of suxamethonium rarely occurs in genotypically normal patients.

Peri-operative management of neuromuscular blockade: A guideline from the European Society of Anaesthesiology and Intensive Care

Recent data indicated a high incidence of inappropriate management of neuromuscular block, with a high rate of residual paralysis and relaxant-associated postoperative complications. These data are alarming in that the available neuromuscular monitoring, as well as myorelaxants and their antagonists basically allow well tolerated management of neuromuscular blockade. In this first European Society of Anaesthesiology and Intensive Care (ESAIC) guideline on peri-operative management of neuromuscular block, we aim to present aggregated and evidence-based recommendations to assist clinicians provide best medical care and ensure patient safety. We identified three main clinical questions: Are myorelaxants necessary to facilitate tracheal intubation in adults? Does the intensity of neuromuscular blockade influence a patient's outcome in abdominal surgery? What are the strategies for the diagnosis and treatment of residual paralysis? On the basis of this, PICO (patient, intervention, comparator, outcome) questions were derived that guided a structured literature search. A stepwise approach was used to reduce the number of trials of the initial research ( n  = 24 000) to the finally relevant clinical studies ( n  = 88). GRADE methodology (Grading of Recommendations, Assessment, Development and Evaluation) was used for formulating the recommendations based on the findings of the included studies in conjunction with their methodological quality. A two-step Delphi process was used to determine the agreement of the panel members with the recommendations: R1 We recommend using a muscle relaxant to facilitate tracheal intubation (1A). R2 We recommend the use of muscle relaxants to reduce pharyngeal and/or laryngeal injury following endotracheal intubation (1C). R3 We recommend the use of a fast-acting muscle relaxant for rapid sequence induction intubation (RSII) such as succinylcholine 1 mg kg -1 or rocuronium 0.9 to 1.2 mg kg -1 (1B). R4 We recommend deepening neuromuscular blockade if surgical conditions need to be improved (1B). R5 There is insufficient evidence to recommend deep neuromuscular blockade in general to reduce postoperative pain or decrease the incidence of peri-operative complications. (2C). R6 We recommend the use of ulnar nerve stimulation and quantitative neuromuscular monitoring at the adductor pollicis muscle to exclude residual paralysis (1B). R7 We recommend using sugammadex to antagonise deep, moderate and shallow neuromuscular blockade induced by aminosteroidal agents (rocuronium, vecuronium) (1A). R8 We recommend advanced spontaneous recovery (i.e. TOF ratio >0.2) before starting neostigmine-based reversal and to continue quantitative monitoring of neuromuscular blockade until a TOF ratio of more than 0.9 has been attained. (1C).

Pseudocholinesterase deficiency in ophthalmology: a systematic review

PURPOSE

Unexpected anesthesia-related complications are among the most feared outcomes of ambulatory surgery. One potential culprit is pseudocholinesterase deficiency, which most commonly presents with protracted apnea, necessitating prolonged mechanical ventilation. We report the first case of pseudocholinesterase deficiency in a Bengali person and the first systematic review of pseudocholinesterase deficiency in ophthalmology. This review analyzed the epidemiology, etiologies, presentation, evaluation, and treatment of pseudocholinesterase deficiency.

METHODS

Searches were conducted in PubMed, Embase, and Medline through August of 2022 for publications related to pseudocholinesterase deficiency in ophthalmology. In total, 689 studies were screened by two independent reviewers with 26 full-text articles examined for inclusion eligibility. Nineteen studies were eligible and included in the final analysis.

RESULTS

Of the 16 identified cases of pseudocholinesterase deficiency, nine (56%) were drug-induced, four (25%) were inherited deficiencies, and in one (6%) of the cases, the cause could not be determined. In two (13%) cases, pseudocholinesterase deficiency could not be confirmed or ruled out. The duration of post-operative apnea ranged from 10 minutes to 14 hours. Continued ventilatory support was the main treatment for all cases and all patients made a full recovery.

CONCLUSIONS

Pseudocholinesterase deficiency is a rare, but potentially fatal, anesthetic complication that results in prolonged apnea, respiratory distress, and dependency on ventilators. Ophthalmologists should remain aware of this condition, especially when planning outpatient procedures, as ambulatory centers may have limited resources for managing prolonged post-operative complications.

Improving neuromuscular monitoring and reducing residual neuromuscular blockade via e-learning: A multicentre interrupted time-series study (INVERT study)

Background

Neuromuscular monitoring should be applied routinely to avoid residual neuromuscular block. However, anaesthetists often refrain from applying it, even when the equipment is available. We aimed to increase neuromuscular monitoring in six Danish anaesthesia departments via e‐learning.

Methods

Interrupted time series study, with baseline data from a previous study and prospective data collection after implementation of the module, which was available for 2 weeks from 21 November 2016. We included all patients receiving general anaesthesia with muscle relaxants until 30 April 2017. Main outcome was application of acceleromyography, grouped as succinylcholine only and non‐depolarising relaxants. Secondary outcomes were last recorded train‐of‐four ratio (non‐depolarising) relaxants and score on a ten‐question pre‐ and post‐course multiple‐choice test.

Results

The post‐intervention data consisted of 6525 cases (3099 (48%) succinylcholine only, 3426 (52%) non‐depolarising relaxants). Analysing all departments, we found a positive pre‐intervention trend in application of acceleromyography for both groups, of estimated 7.5% and 4.8% per year, respectively (p < .001). The monitoring rate increased significantly for succinylcholine in two departments post‐intervention (p = .045 and .010), and for non‐depolarising relaxants in one department (p = .041), but followed by a negative trend of −37.0% per year (p = .041). The rate was already close to 90% at the time of the intervention and the mean last recorded train‐of‐four ratio was 0.97 (SD 0.21), also without a significant change. The median score on the post‐course test increased from 7 (IQR 5–8) to 9 (IQR 8–10) (p < .001, Wilcoxon Signed‐Ranks Test).

Conclusion

We found no overall effect of the e‐learning module on application of neuromuscular monitoring, although the post‐course test indicated an effect on anaesthetists’ knowledge in this field.

Trial registration

Trial registration: Clinicaltrials.gov identifier: NCT02925143. https://clinicaltrials.gov/ct2/show/NCT02925143

Cholinesterase activity in serum during general anesthesia in patients with or without vascular disease

Maintaining hemodynamic stability during the induction and maintenance of anesthesia is one of the challenges of the anesthesiologist. Patients with vascular disease are at increased risk of instability due to imbalance between the sympathetic and parasympathetic parts of the autonomic nervous system, a balance accessible by serum cholinesterase activity. We aim to characterize the dynamics of cholinesterase activity in patients undergoing general anesthesia (GA) and surgery. This was a prospective study of 57 patients undergoing ambulatory or vascular surgery under GA. Cholinesterase activity was measured before the induction of anesthesia, after 15 min and at the end of surgery by calculating the capacity of serum acetylcholinesterase (AChE) and butyrylcholinesterase to hydrolyze AcetylThioCholine. Data on atherosclerotic disease, anesthesia management were analyzed. Both AChE and total cholinergic status (CS) decreased significantly after GA induction at 15 min and even more so by the end of surgery. Vascular surgery patients had lower baseline cholinesterase activity compared to ambulatory surgery patients. Patients requiring intraoperative administration of phenylephrine for hemodynamic support (21.1%) had a significantly lower level of AChE and CS compared to untreated patients. Our findings serve as a mirror to the sympathetic/parasympathetic imbalance during GA, with a marked decrease in the parasympathetic tone. The data of a subgroup analysis show a correlation between low cholinesterase activity and an increase in the need for hemodynamic support.

Delayed Emergence from Anesthesia: What We Know and How We Act

The emergence from anesthesia is the stage of general anesthesia featuring the patient’s progression from the unconsciousness status to wakefulness and restoration of consciousness. This complex process has precise neurobiology which differs from that of induction. Despite the medications commonly used in anesthesia allow recovery in a few minutes, a delay in waking up from anesthesia, called delayed emergence, may occur. This phenomenon is associated with delays in the operating room, and an overall increase in costs. Together with the emergence delirium, the phenomenon represents a manifestation of inadequate emergence. Nevertheless, in delayed emergence, the transition from unconsciousness to complete wakefulness usually occurs along a normal trajectory, although slowed down. On the other hand, this awakening trajectory could proceed abnormally, possibly culminating in the manifestation of emergence delirium. Clinically, delayed emergence often represents a challenge for clinicians who must make an accurate diagnosis of the underlying cause to quickly establish appropriate therapy. This paper aimed at presenting an update on the phenomenon, analyzing its causes. Diagnostic and therapeutic strategies are addressed. Finally, therapeutic perspectives on the “active awakening” are reported.

<p>Genetic Testing for <em>BCHE</em> Variants Identifies Patients at Risk of Prolonged Neuromuscular Blockade in Response to Succinylcholine</p>

Background

Genetic variants in the BCHE (butyrylcholinesterase) gene are associated with reduced BChE enzyme activity and prolonged post-succinylcholine neuromuscular blockade, which can lead to postanesthetic apnea and respiratory depression. Testing for BChE deficiency is usually performed by biochemical methods and is generally only offered to patients who have a personal or family history of prolonged post-succinylcholine neuromuscular blockade.

Purpose

Using a clinical test, we investigated the frequencies of BCHE genotypes that are associated with increased risk for prolonged post-succinylcholine neuromuscular blockade.

Materials and Methods

Five BCHE variants, including the A (atypical, rs1799807), K (Kalow, rs1803274), F₁ (fluoride-1, rs28933389), F₂ (fluoride-2, rs28933390), and S₁ (silent-1, rs398124632), were genotyped in a large (n = 13,301), multi-ethnic cohort in the United States. Subjects were recipients of pharmacogenetic testing ordered by their physicians as part of routine care.

Results

The minor allele frequencies of A, K, F₁, F₂, and S₁ were 1.60%, 19.93%, 0.08%, 0.47%, and 0.04%, respectively, in this cohort. Based on a review of biochemical and clinical data of these variants, we grouped BCHE genotypes into four phenotypic categories to stratify the risk for prolonged post-succinylcholine neuromuscular blockade. Approximately 0.06% of patients were predicted to have severe BChE deficiency, 8% were predicted to have moderate BChE deficiency, and 29% were predicted to have mild BChE deficiency. Compared to other ethnic groups, Caucasians were predicted to have the highest frequency of BChE deficiency.

Conclusion

While severe BChE deficiency is rare in the United States, approximately 8% of Americans are at moderate risk of prolonged post-succinylcholine neuromuscular blockade, suggesting that a sizable percentage of patients may benefit from preoperative genetic testing of BCHE.

Barriers and aids to routine neuromuscular monitoring and consistent reversal practice-A qualitative study

Background

Neuromuscular monitoring is recommended whenever a neuromuscular blocking agent is administered, but surveys have demonstrated inconsistent monitoring practices. Using qualitative methods, we aimed to explore barriers and aids to routine neuromuscular monitoring and consistent reversal practice.

Methods

Focus group interviews were conducted to obtain insights into the thoughts and attitudes of individual anaesthetists, as well as the influence of colleagues and department culture. Interviews were conducted at five Danish and one US hospital. Data were analysed using template analysis.

Results

Danish anaesthetists used objective neuromuscular monitoring when administering a non‐depolarizing relaxant, but had challenges with calibrating the monitor and sometimes interpreting measurements. Residents from the US institution used subjective neuromuscular monitoring, objective neuromuscular monitoring was generally not available and most had not used it. Danish anaesthetists used neuromuscular monitoring to assess readiness for extubation, whereas US residents used subjective neuromuscular monitoring, clinical tests like 5‐second head lift and ventilatory parameters. The residents described a lack of consensus between senior anaesthesiologists in reversal practice and monitoring use. Barriers to consistent and correct neuromuscular monitoring identified included unreliable equipment, time pressure, need for training, misconceptions about pharmacokinetics of neuromuscular blocking agents and residual block, lack of standards and guidelines and departmental culture.

Conclusion

Using qualitative methods, we found that though Danish anaesthetists generally apply objective neuromuscular monitoring routinely and residents at the US institution often apply subjective neuromuscular monitoring, barriers to consistent and correct use still exist.

A retrospective observational study of neuromuscular monitoring practice in 30,430 cases from six Danish hospitals

Timely application of objective neuromuscular monitoring can avoid residual neuromuscular blockade. We assessed the frequency of objective neuromuscular monitoring with acceleromyography and the last recorded train‐of‐four ratio in a cohort of Danish patients. We extracted data from all patients receiving general anaesthesia from November 2014 to November 2016 at six hospitals in the Zealand Region of Denmark. Acceleromyography was available in all operating rooms and data were recorded automatically. The primary outcome measure was acceleromyography use in patients receiving neuromuscular blocking agents, divided into non‐depolarising agents and succinylcholine only. The dataset included 76,743 cases, of which 30,430 received a neuromuscular blocking drug. Non‐depolarising drugs were used in 16,525 (54%) and succinylcholine as the sole drug in 13,905 (46%) cases. Acceleromyography was used in 14,463 (88%) patients who received a non‐depolarising neuromuscular blocking drug and in 4224 (30%) receiving succinylcholine alone. Acceleromyography use varied between the departments from 58% to 99% for non‐depolarising drugs and from 3% to 79% for succinylcholine alone. The median (IQR [range]) of the last recorded train‐of‐four ratio before tracheal extubation was 0.97 (0.90–1.06 [0.01–2.20]) when non‐depolarising drugs were used, and was less than 0.9 in 22% of cases. The OR for oxygen desaturation was higher with the use of succinylcholine [2.51 (95%CI 2.33–2.70) p < 0.001] and non‐depolarising drugs [2.57 (95%CI 2.32–2.84) p < 0.001] as compared with cases where no neuromuscular blockade drug was used. In conclusion, acceleromyography was almost always used in cases where non‐depolarising neuromuscular blocking drugs were used, but a train‐of‐four ratio of 0.9 was not always achieved. Monitoring was used in less than 30% of cases where succinylcholine was the sole drug used.

Awareness during emergence from anesthesia: Features and future research directions

The anesthesia awareness with recall (AAWR) phenomenon represents a complication of general anesthesia consisting of memorization of intraoperative events reported by the patient immediately after the end of surgery or at a variable distance from it. Approximately 20% of AAWR cases occur during emergence from anesthesia. Clinically, these unexpected experiences are often associated with distress especially due to a sense of paralysis. Indeed, although AAWR at the emergence has multiple causes, in the majority of cases the complication develops when the anesthesia plan is too early lightened at the end of anesthesia and there is a lack of use, or misuse, of neuromuscular monitoring with improper management of the neuromuscular block. Because the distress caused by the sense of paralysis represents an important predictor for the development of severe psychological complications, the knowledge of the phenomenon, and the possible strategies for its prophylaxis are aspects of considerable importance. Nevertheless, a limited percentage of episodes of AAWR cannot be prevented. This paradox holds also during the emergence phase of anesthesia which represents a very complex neurophysiological process with many aspects yet to be clarified.

Sugammadex: Appropriate Use in the Context of Budgetary Constraints

Purpose of Review

The purpose of this review is to assess how sugammadex impacts postoperative residual curarization using appropriate doses based on neuromuscular transmission monitoring and whether the advantages of sugammadex versus neostigmine outweigh its higher cost.

Recent Findings

An accurate assessment of neuromuscular blockade with monitoring is necessary before selecting neostigmine versus sugammadex for reversal at the end of surgery to overcome incomplete neuromuscular recovery. The main advantages of sugammadex over neostigmine are its predictability and its ability to extend the range of blockade reversal. The cost of sugammadex is greater when higher doses of sugammadex are required for antagonism of deep block. Sugammadex probably has the potential to be cost-effective compared with neostigmine if its time savings are put to productive use in clinical practice. However, to date, the economic benefits of the drug are unknown.

Summary

With sugammadex, almost any degree of neuromuscular block can be antagonized within 2–3 min; neostigmine is the only reversal agent effective against benzylisoquinolines and can ideally be used for reversal of lower levels of residual paralysis. The performance of the more expensive sugammadex on improving patient outcomes may depend on several elements of clinical strategy.

Improving Neuromuscular Monitoring and Reducing Residual Neuromuscular Blockade With E-Learning: Protocol for the Multicenter Interrupted Time Series INVERT Study

Background

Muscle relaxants facilitate endotracheal intubation under general anesthesia and improve surgical conditions. Residual neuromuscular blockade occurs when the patient is still partially paralyzed when awakened after surgery. The condition is associated with subjective discomfort and an increased risk of respiratory complications. Use of an objective neuromuscular monitoring device may prevent residual block. Despite this, many anesthetists refrain from using the device. Efforts to increase the use of objective monitoring are time consuming and require the presence of expert personnel. A neuromuscular monitoring e-learning module might support consistent use of neuromuscular monitoring devices.

Objective

The aim of the study is to assess the effect of a neuromuscular monitoring e-learning module on anesthesia staff’s use of objective neuromuscular monitoring and the incidence of residual neuromuscular blockade in surgical patients at 6 Danish teaching hospitals.

Methods

In this interrupted time series study, we are collecting data repeatedly, in consecutive 3-week periods, before and after the intervention, and we will analyze the effect using segmented regression analysis. Anesthesia departments in the Zealand Region of Denmark are included, and data from all patients receiving a muscle relaxant are collected from the anesthesia information management system MetaVision. We will assess the effect of the module on all levels of potential effect: staff’s knowledge and skills, patient care practice, and patient outcomes. The primary outcome is use of neuromuscular monitoring in patients according to the type of muscle relaxant received. Secondary outcomes include last recorded train-of-four value, administration of reversal agents, and time to discharge from the postanesthesia care unit as well as a multiple-choice test to assess knowledge. The e-learning module was developed based on a needs assessment process, including focus group interviews, surveys, and expert opinions.

Results

The e-learning module was implemented in 6 anesthesia departments on 21 November 2016. Currently, we are collecting postintervention data. The final dataset will include data from more than 10,000 anesthesia procedures. We expect to publish the results in late 2017 or early 2018.

Conclusions

With a dataset consisting of thousands of general anesthesia procedures, the INVERT study will assess whether an e-learning module can increase anesthetists’ use of neuromuscular monitoring.

Trial Registration

Clinicaltrials.gov NCT02925143; https://clinicaltrials.gov/ct2/show/NCT02925143 (Archived by WebCite® at http://www.webcitation.org/6s50iTV2x)

Current Status of Neuromuscular Reversal and Monitoring

Postoperative residual neuromuscular block has been recognized as a potential problem for decades, and it remains so today. Traditional pharmacologic antagonists (anticholinesterases) are ineffective in reversing profound and deep levels of neuromuscular block; at the opposite end of the recovery curve close to full recovery, anticholinesterases may induce paradoxical muscle weakness. The new selective relaxant-binding agent sugammadex can reverse any depth of block from aminosteroid (but not benzylisoquinolinium) relaxants; however, the effective dose to be administered should be chosen based on objective monitoring of the depth of neuromuscular block.

To guide appropriate perioperative management, neuromuscular function assessment with a peripheral nerve stimulator is mandatory. Although in many settings, subjective (visual and tactile) evaluation of muscle responses is used, such evaluation has had limited success in preventing the occurrence of residual paralysis. Clinical evaluations of return of muscle strength (head lift and grip strength) or respiratory parameters (tidal volume and vital capacity) are equally insensitive at detecting neuromuscular weakness. Objective measurement (a train-of-four ratio greater than 0.90) is the only method to determine appropriate timing of tracheal extubation and ensure normal muscle function and patient safety.

Delayed recovery from paralysis associated with plasma cholinesterase deficiency

Introduction

This case was to describe a patient presented a 6 h length of apnea associated with low cholinesterase activity.

Case description

A 32 years old female patient (body weight 50 kg, height 160 cm) was admitted to the hospital for laparoscopy combined with hysteroscopy exploration. The preoperative interrogation revealed no significant personal or family history of adverse reaction to anesthetics. The patient was healthy, with no chronic or systemic disease. ASA classification is I. We performed a general anesthesia with intubation to the patient. Succinylcholine 100 mg was administered in anesthesia induction. After intubation, cisatracurium 3 mg and 3% sevoflurane were used for anesthesia maintenance. The patient had been mostly unresponsive to external stimuli for 10 min since the end of the operation. Six hours after operation, the patient had totally recovered from paralysis and tracheal tube was extubated. The plasma cholinesterase test showed 291 U/L, significantly below normal (4650–10,440 U/L). Three days after operation, the patient was discharged from hospital with no special discomfort.

Discussion and evaluation

Reduced plasma cholinesterase activity may occur as a result of inherited, acquired defects or iatrogenic causes. If the acquired defects are excluded, low BChE activity is usually considered to be caused by mutations in butyrylcholinesterase gene (BCHE). 80% of the patients experiencing prolonged neuromuscular blockade following mivacurium have butyrylcholinesteraseen enzyme (BChE) deficiency of genetic origin. The novel mutation of BChE gene is usually associated with the ethnic of the patients. There is no specific treatment for butyrylcholinesterase deficiency and the mainstream is to maintain ventilatory support until succinlcholine is metabolized out of the myoneural junction and neuromuscular function recovers. Transfusion of fresh frozen plasma is also viable.

Conclusions

Plasma cholinesterase deficiency is a genetic or acquired condition. The most obvious feature of this genetic variants is prolonged recovery from paralysis in which administrated with succinylcholine or mivacurium. Once this is suspected, a laboratory test is important. There is no specific treatment for plasma cholinesterase deficiency. The best and safest way is to let the patient recover spontaneously. Mechanical ventilation support is important.

Postoperative awake paralysis in the intensive care unit after cardiac surgery due to residual neuromuscular blockade: a case report and prospective observational study

PURPOSE

We report a case of awake paralysis due to residual neuromuscular blockade (NMB) in the intensive care unit (ICU) in a patient following fast-track cardiac surgery. As a result of this case, we performed a prospective quality assurance audit to investigate the incidence of residual paralysis in the ICU in a similar population of cardiac surgery patients.

CLINICAL FEATURES AND AUDIT METHODS

A 73-yr-old woman (69 kg) underwent coronary artery bypass surgery under anesthesia induced with intravenous sufentanil 25 µg, midazolam 5 mg, ketamine 25 mg, and rocuronium 100 mg (followed by two additional 50-mg doses during surgery) and maintained with sevoflurane. Postoperatively in the ICU, the patient was initially sedated with propofol (50 mg·hr(-1)) but failed to awaken 90 min after its cessation. As train-of-four neurostimulation showed residual paralysis, she was re-sedated. Neostigmine 3 mg and glycopyrrolate 0.6 mg were administered, and she was extubated 30 min later. During this episode of residual paralysis, the patient was conscious and reported explicit memory of the events. She was discharged on day 7 without psychological distress related to her postoperative awake paralysis. We subsequently performed a prospective audit in 50 consecutive patients to determine the timing of NMB dosing and to quantify the incidence of residual paralysis after fast-track cardiac surgery.

RESULTS

Of the 50 patients studied, 24 (48%) had received an NMB during the last hour of surgery and 33 (66%) had evidence of residual paralysis during the immediate postoperative period.

CONCLUSION

Postoperative residual paralysis after fast-track cardiac surgery was common in our institution and likely contributed to the reported case of postoperative awake paralysis. We suggest that an NMB not be administered after intubation in fast-track patients. If given, however, it must be well communicated to the ICU team upon ICU admission. We further recommend routine assessment of neuromuscular function before sedation is weaned prior to extubation.

A 7-Year Retrospective Multisource Analysis on the Incidence of Anesthesia Awareness With Recall in Cancer Patients: A Chance of Collaboration Between Anesthesiologists and Psycho-Oncologists for Awareness Detection

Although randomized controlled studies reported an incidence of anesthesia awareness with recall ∼1 to 2 per 1000 (0.1-0.2%), recent data from the NAP5 study showed an incidence of only 1:19,600. Although in a prospective study many tools for anesthesia awareness detection can be used, a retrospective analysis requires a careful collection of information.The aim of the study was to evaluate the incidence of anesthesia awareness with recall in a cohort of cancer patients through a multisource retrospective analysis, and the clinical description, including the psychological outcome, of the cases detected. We also tested whether our retrospective analysis would be improved by a routinely psycho-oncological assessment. As secondary endpoints we evaluated the use of depth of anesthesia monitoring over a large cohort of patients, and the correlation between the brain monitoring and the incidence of awareness.We have carried out a 7-year retrospective analysis in a large cohort of cancer patients on the incidence of awareness with recall during general anesthesia. Of 35,595 patients assessed for eligibility, 21,099 were studied. We analyzed all data from the operative rooms' database, the anesthesia records, and from the database of the surgical divisions. In addition we examined reports from psychologists and spontaneous reports to the quality team of the hospital.Two certain cases of awareness were detected, with an incidence of 1:10,550 (0.0095%). They occurred during elective surgery, in female patients without other risk factors. One case came from the report of a psychologist. In both episodes, brain monitoring was not applied and no long-term psychological sequelae were reported.Despite the limitations, our investigation suggests that the incidence of anesthesia awareness is very low, also in a specific cohort of patients, such as the cancer patients, and even when the depth of anesthesia monitoring is rarely used. The limitations caused by both the retrospective analysis and the absence of specific tools for direct awareness detection, such as structured interviews, can be filled with an effective postoperative psychological assessment which is often of routine in a cancer center. This observation could suggest the usefulness of inserting specific questions within the psychological tools commonly used by psycho-oncologists.