Volatile capture technology in sustainable anaesthetic practice: a narrative review

Anaesthetic practice contributes to climate change. Volatile capture technology, typically based on adsorption to a carbon- or silica-based substrate, has the potential to mitigate some of the harmful effects of using halogenated hydrocarbons. Anaesthetists have a professional responsibility to use anaesthetic agents which offer the greatest safety and clinical benefit with the lowest financial cost and environmental impacts. Inhalational anaesthetics should be used at an appropriate concentration with a minimal fresh gas flow via a circle system to minimise unnecessary waste. Once practice efficiencies have been maximised, only then should technical solutions such as volatile capture be employed. In this narrative review, we focus on the available literature relating to volatile capture technology, obtained via a targeted literature search and through contacting manufacturers and researchers. We found six studies focusing on the Blue-Zone Technologies Deltasorb®, SageTech Medical SID and Baxter/ZeoSys CONTRAfluran™ volatile capture systems. Though laboratory analyses of available systems suggest that > 95% in vitro mass transfer is possible for all three systems, the in vivo results for capture efficiency vary from 25% to 73%. Currently, there is no financial incentive for healthcare organisations to capture waste anaesthetic gases, and so the value of volatile capture technology requires quantification. System-level organisations, such as Greener NHS, are best positioned to commission such evaluations and make policy decisions to guide investment. Further research using volatile capture technology in real-world settings is necessary and we highlight some priority research questions to improve our understanding of the utility of this group of technologies.

A Multi-Theoretical and Multi-Method Family Study Approach to Preschool Inhibitory Control: Links to Working Memory, Receptive Vocabulary, Behavioral Maladjustment, and Parent Mental Health in the Context of Temperament and Executive Functioning Perspectives

Inhibitory control (IC) is defined as the executive functioning (EF) and self-regulatory temperamental inhibition of impulsive or pre-potent behavior and has been consistently linked to multiple forms of childhood cognitive and socio-emotional maladjustment including academic and learning challenges, externalizing behaviors, and attention deficit hyperactivity disorder. However, the results of relevant investigations are somewhat dependent on the method of IC assessment and the theoretical approach of the researcher. The two primary theoretical perspectives on IC are the temperament and the EF approaches, and although there is considerable overlap between these perspectives, there are some distinctions with regard to assessment and emphases on cognition vs. emotion. Therefore, investigations including both temperament and EF approaches to IC are of considerable interest and will best inform future education, prevention, and intervention efforts. This investigation examined associations between child IC, working memory (WM), receptive vocabulary, externalizing behavioral problems, and primary caregiver depression and anxiety symptoms using a family study design. The sample was composed of 99 families with two typically developing preschool children (n = 198; 2.5-5.5 years old; M = 3.88, SD = 1.04) and one primary caregiver/parent. Child IC was assessed using a multi-method approach consisting of one parent-rated questionnaire, three independent observer rating subscales, two videotaped in-person laboratory temperament episodes, and an EF Stroop task. Child WM and receptive vocabulary were measured in the laboratory using standard assessment techniques, and the remaining measures were parent-reported. Male child participants had significantly higher levels of observer-rated hyperactivity and impulsivity, and females had higher levels of observer-rated attention and Stroop-assessed IC. Correlational results showed that excepting IC-Stroop and a snack delay task, all IC measures were significantly correlated. All IC measures except snack delay were positively correlated with WM, and with receptive vocabulary (except Lab-TAB snack delay and observer-rated hyperactivity), and WM and receptive vocabulary were also positively correlated. All IC variables, WM, and receptive vocabulary were significantly related to externalizing behavior problems. Generally, children with higher IC, WM, and receptive vocabulary had lower levels of behavioral maladjustment. Lower parent-rated IC and higher levels of externalizing behavior problems were positively associated with maternal depression and anxiety (lower receptive vocabulary level was related to depression only). Employing structural equation modeling (SEM) analyses, we further examined the interrelationships among IC temperament variables, IC-Stroop, WM, and receptive vocabulary, controlling for age, gender, externalizing behaviors, maternal depression and anxiety, and the parent-rater variance (the multi-method effect). The results of our hypothesized model showed that the IC Temperament factor, composed of the six temperament IC measures, showed a positive effect on receptive vocabulary, while the IC-Stroop positively predicted WM. The IC Temperament factor and IC-Stroop were positively correlated with each other, and the IC Temperament factor, IC-Stroop, WM, and receptive vocabulary were positively related to age. The IC Temperament factor was also associated with fewer externalizing behavior problems, maternal depression had a negative effect on receptive vocabulary, and females showed lower levels of WM and receptive vocabulary than males. Overall, the IC Temperament factor and other covariates together accounted for 22.5% of the variance in vocabulary, whereas IC-Stroop and other controlled variables could explain 49.8% of the variance in WM. These findings indicate that theoretical perspectives (in this case temperament and EF IC contexts) and the different types of assessments used are crucial considerations when interpreting the results of studies of early childhood IC. Although most assessments of IC were associated with the outcomes under study, we found specific associations between temperament measures of IC and receptive vocabulary as well as externalizing, and IC-Stroop and WM. In addition, maternal depression had an effect on receptive vocabulary, emphasizing the developmental importance of family environment in preschool. These findings are relevant to the field of child development because they address several important questions about child EF and self-regulation. 1. Do temperament and EF conceptions of IC differentially predict outcomes? 2. How does the way we measure IC from the EF and self-regulation/temperament perspectives impact our conceptualizations of these important constructs? 3. How can we reconcile the various ways different disciplines define IC and their independence/overlap? 4. How can multi-method and multi-disciplinary perspectives and data collection approaches be combined to better understand both the temperament and EF conceptions of IC? Future studies with this sample will employ this multi-theoretical and multi-method approach on assessment in preschool to predict temperament, EF, and behavioral and academic adjustment in elementary school longitudinally.

Impact of a national enhanced recovery after surgery programme on patient outcomes of primary total knee replacement: an interrupted time series analysis from "The National Joint Registry of England, Wales, Northern Ireland and the Isle of Man"

OBJECTIVE

We aimed to test whether a national Enhanced Recovery After Surgery (ERAS) Programme in total knee replacement (TKR) had an impact on patient outcomes.

DESIGN

Natural-experiment (April 2008-December 2016). Interrupted time-series regression assessed impact on trends before-during-after ERAS implementation.

SETTING

Primary operations from the UK National Joint Registry (NJR) were linked with Hospital Episode Statistics (HES) data which contains inpatient episodes undertaken in National Health Service (NHS) trusts in England, and Patient Reported Outcome Measures (PROMs).

PARTICIPANTS

Patients undergoing primary planned TKR aged ≥18 years.

INTERVENTION

ERAS implementation (April 2009-March 2011).

OUTCOMES

Regression coefficients of monthly means of Length of stay (LOS), bed day costs, change in Oxford knee scores (OKS) 6-months after surgery, complications (at 6 months), and rates of revision surgeries (at 5 years).

RESULTS

486,579 primary TKRs were identified. Overall LOS and bed-day costs decreased from 5.8 days to 3.7 and from £7607 to £5276, from April 2008 to December 2016. Oxford knee score (OKS) change improved from 15.1 points in April 2008 to 17.1 points in December 2016. Complications decreased from 4.1 % in April 2008 to 1.7 % in March 2016. 5-year revision rates remained stable at 4.8 per 1000 implants years in April 2008 and December 2011. After ERAS, declining trends in LOS and bed costs slowed down; OKS improved, complications remained stable, and revisions slightly increased.

CONCLUSIONS

Different secular trends in outcomes for patients having TKR have been observed over the last decade. Although patient outcomes are better than a decade ago ERAS did not improve them at national level.

A survey of dog and cat anaesthesia in a sample of veterinary practices in New Zealand

AIMS

To survey current anaesthesia practices for dogs and cats in small and mixed animal practices in New Zealand in order to improve anaesthesia education.

METHODS

A questionnaire was sent to 440 small and mixed animal practices, including questions regarding the type of practice, preanaesthetic examination, anaesthetic drugs and management, anaesthetic machines, monitoring and topics of interest for continuing professional development.

RESULTS

Responses were obtained from 113/440 (26%) practices, with 78 (69%) respondents from small and 35 (31%) from mixed animal practices. A preanaesthetic physical examination was carried out by >95% of respondents and premedication was usually given to dogs (112/113; 99%) and cats (95/113; 85%). Acepromazine was the preferred sedative for dogs and cats, with morphine or buprenorphine. Propofol and alfaxalone were the preferred induction agents, and isoflurane was preferred for maintenance in both dogs and cats. A venous catheter was usually placed for anaesthesia in dogs (59/113; 52%), but less so in cats (39/113; 35%). Perioperative fluid was administered at 10 mL/kg/hour by 62/110 (56%) respondents. Intubation was usually used for anaesthesia in dogs (111/112; 99%), and cats (87/112; 78%). Almost 40% of respondents usually administered supplementary oxygen if patients were not intubated. Local analgesia was used by 69/111 (88%) respondents sometimes or always if applicable. Morphine or buprenorphine, and meloxicam were common choices for post-operative analgesia after neuter surgery in dogs and cats. A semiclosed (non-rebreathing) system was used in animals weighing <10 kg, and a Mapleson E or F non-rebreathing circuit was used by 66/109 (61%) practices. Only 15/111 (14%) practices had a ventilator in their practice. A dedicated anaesthetist was usually used by 104/113 (92%) practices, and apnoea alarms, pulse oximeters, thermometers and oesophageal stethoscopes were the main monitoring devices available in practices. Loco-regional block, pain management, and anaesthetic drugs were the main topics of interest for continuing education.

CONCLUSIONS AND CLINICAL RELEVANCE

Responses by the veterinarians taking part in this survey indicated that they had a reasonably good standard of anaesthetic practice. A physical examination was carried out preanaesthesia, and premedication including analgesia was routinely administered to most patients. A dedicated anaesthetist usually monitored patients and most respondents reported they had access to basic anaesthetic monitoring equipment. Areas where changes could lead to improved anaesthetic practice were increased use of I/V catheterisation, endotracheal intubation, and supplementary oxygen, and reduced I/V fluid rates.