Avoiding pain during propofol injection in pediatric anesthesia: Hypnoanalgesia of the hand versus intravenous lidocaine

INTRODUCTION

Pain related to injection of propofol during induction of anesthesia decreases from 66.8% without prevention, to 22-31% of cases when lidocaine is associated. Hypnoanalgesia of the hand is currently used for painful procedures in children but has never been evaluated in this indication. The primary aim of this prospective randomized single-blind study was to evaluate the efficacy of hypnoanalgesia of the hand for the prevention of moderate to severe pain during intravenous injection of propofol alone in comparison to lidocaine admixture. The secondary aim was to compare the global satisfaction of children in both methods.

PATIENTS AND METHODS

One hundred patients aged 7-14 years, ASA 1-2, admitted for scheduled surgery under general anesthesia were randomized into two groups. Group L received a mixture of 1% propofol (3 mg/kg) and 1% Lidocaine (0.3 mg/kg). Group H received 1% propofol (3 mg/kg) after hypnoanalgesia of the hand realized by a single experimented operator. A video was made in order to evaluate the pain related to propofol injection by a blinded observer using the 4-point score of Cameron (painful ≥ 2). The global satisfaction of children was evaluated in postanesthesia care unit and documented if visual analog score was <7/10.

RESULTS

Ninety-six patients were analyzed. The rate of painful patients did not differ significantly between groups (8.5% in group H [n = 47] vs 6.1% in group L [n = 49], OR= 0.70; 95% CI [0.13-3.35], p = 0.65), nor did the rate of nonsatisfied patients (10.6 in group H vs. 12.2% in group L, OR = 0.85; 95% CI [0.19-3.65], p = 1).

CONCLUSIONS

Our results suggest that hypnoanalgesia of the hand alone is effective to prevent the pain related to propofol injection in children. No significant difference was found in comparison with lidocaine admixture nor for pain or satisfaction.

A biophysical framework for double-drugging kinases

Orthosteric inhibition of kinases has been challenging due to the conserved active site architecture of kinases and emergence of resistance mutants. Simultaneous inhibition of distant orthosteric and allosteric sites, which we refer to as "double-drugging", has recently been shown to be effective in overcoming drug resistance. However, detailed biophysical characterization of the cooperative nature between orthosteric and allosteric modulators has not been undertaken. Here, we provide a quantitative framework for double-drugging of kinases employing isothermal titration calorimetry, Förster resonance energy transfer, coupled-enzyme assays, and X-ray crystallography. We discern positive and negative cooperativity for Aurora A kinase (AurA) and Abelson kinase (Abl) with different combinations of orthosteric and allosteric modulators. We find that a conformational equilibrium shift is the main principle governing this cooperative effect. Notably, for both kinases, we find a synergistic decrease of the required orthosteric and allosteric drug dosages when used in combination to inhibit kinase activities to clinically relevant inhibition levels. X-ray crystal structures of the doubledrugged kinase complexes reveal the molecular principles underlying the cooperative nature of double-drugging AurA and Abl with orthosteric and allosteric inhibitors. Finally, we observe the first fully-closed conformation of Abl when bound to a pair of positively cooperative orthosteric and allosteric modulators, shedding light onto the puzzling abnormality of previously solved closed Abl structures. Collectively, our data provide mechanistic and structural insights into rational design and evaluation of doubledrugging strategies.

Teleconsultation in pediatric anesthesia: first assessment of feasibility, quality and satisfaction in France

INTRODUCTION

The COVID-19 pandemic has prompted the development of anesthesia teleconsultation in many countries. In pediatric anesthesia, data about anesthesia teleconsultation are scarce. The main objective of this prospective descriptive study was to provide an evaluation of the feasibility of pediatric anesthesia teleconsultation. Perception of the safety and quality, parental and medical satisfaction were also assessed.

METHODS

From September to December 2020, patients undergoing a pediatric anesthesia teleconsultation in Toulouse University Hospital, using the Teleo™ dedicated teleconsultation platform were prospectively included. Feasibility was defined as the rate of anesthesia teleconsultations successfully performed using the TeleO™ platform alone. Questionnaires regarding the quality, safety and satisfaction were filled out by physicians and families.

RESULTS

114 children (3 months - 17 years) were included in the study. Feasibility was 82%, failure was mainly caused by technical issues. Physicians estimated that the safety and quality of anesthetic preparation were optimal in 100% of cases. Anesthetists were satisfied (VAS ≥ 70/100) with the medical, technical, and relational (child / parents) aspects of anesthesia teleconsultation in 91%, 64%, and 84% / 90% of cases respectively. Almost all parents (97%) stated that they would agree to anesthesia teleconsultation for a future procedure.

CONCLUSION

In this first assessment, pediatric anesthesia teleconsultation appears to be feasible, with high rates of medical and parental satisfaction. Physicians' perception of the safety and quality of this process were positive. Improving the technical process might be a key determinant to promote further development of pediatric anesthesia teleconsultation.

Ventilation in pediatric anesthesia: A French multicenter prospective observational study (PEDIAVENT)

INTRODUCTION

Protective ventilation is now a standard of care in adults. However, management of ventilation is heterogeneous in children and little is known regarding the mechanical ventilation parameters actually used during pediatric anesthesia.

AIM

The aim of the study was to assess current ventilatory practices during pediatric anesthesia in France and to compare them with pediatric experts' statements, with a specific focus on tidal volume.

PATIENTS AND METHODS

We conducted a prospective multicenter observational study, regarding the ventilatory management and the mechanical ventilation parameters, over two days (21 and 22 June 2017) in 29 pediatric centers in France. All children undergoing general anesthesia during these 2 days were eligible; those who required extracorporeal circulation or one-lung ventilation were excluded.

RESULTS

A total of 701 children were included; median [IQR] age was 60 [24-120] months. Among the patients in whom controlled ventilation was used, 254/515 (49.3%) had an expired tidal volume >8 mL/kg and 44 children (8.8%) an expired tidal volume ≥10 mL/kg. Lower weight and use of a supraglottic airway device were significantly associated with provision of a tidal volume ≥10 mL/kg (odds ratio 0.94, 95% confidence interval [0.92; 0.97], P < .001 and 2.28 [1.20; 4.31], P = .012, respectively). The positive end-expiratory pressure was set at a median [IQR] of 4 [3-5] cmH₂ O; it was <3 cmH₂ O in 15.7% of children and not used in 56/499 (9.3%). Among intubated children, 57 (18.3%) received a tidal volume < 10 mL/kg with a positive end-expiratory pressure ≥3 cmH₂ O in association with recruitment maneuvers.

CONCLUSIONS

Ventilatory practices in children were heterogenous, and a large proportion of children were not ventilated as it is currently recommended by some experts.

Guidelines: Anaesthesia in the context of COVID-19 pandemic

OBJECTIVES

The world is currently facing an unprecedented healthcare crisis caused by the COVID-19 pandemic. The objective of these guidelines is to produce a framework to facilitate the partial and gradual resumption of intervention activity in the context of the COVID-19 pandemic.

METHODS

The group has endeavoured to produce a minimum number of recommendations to highlight the strengths to be retained in the 7 predefined areas: (1) protection of staff and patients; (2) benefit/risk and patient information; (3) preoperative assessment and decision on intervention; (4) modalities of the preanaesthesia consultation; (5) specificity of anaesthesia and analgesia; (6) dedicated circuits and (7) containment exit type of interventions.

RESULTS

The SFAR Guideline panel provides 51 statements on anaesthesia management in the context of COVID-19 pandemic. After one round of discussion and various amendments, a strong agreement was reached for 100% of the recommendations and algorithms.

CONCLUSION

We present suggestions for how the risk of transmission by and to anaesthetists can be minimised and how personal protective equipment policies relate to COVID-19 pandemic context.

Management of the child's airway under anaesthesia: The French guidelines

OBJECTIVE

To provide French guidelines about "Airway management during paediatric anaesthesia".

DESIGN

A consensus committee of 17 experts from the French Society of Anaesthesia and Intensive Care Medicine (Société Française d'Anesthésie-Réanimation, SFAR) and the Association of French speaking paediatric anaesthesiologists and intensivists (Association Des Anesthésistes Réanimateurs Pédiatriques d'Expression Francophone, ADARPEF) was convened. The entire process was conducted independently of any industry funding. The authors followed the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to assess the quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised. Few recommendations were not graded.

METHODS

The panel focused on 7 questions: 1) Supraglottic Airway devices 2) Cuffed endotracheal tubes 3) Videolaryngoscopes 4) Neuromuscular blocking agents 5) Rapid sequence induction 6) Airway device removal 7) Airway management in the child with recent or ongoing upper respiratory tract infection. Population, intervention, comparison, and outcomes (PICO) questions were reviewed and updated as needed, and evidence profiles were generated. The analysis of the literature and the redaction of the recommendations were then conducted according to the GRADE® methodology.

RESULTS

The SFAR Guideline panel provides 17 statements on "airway management during paediatric anaesthesia". After two rounds of discussion and various amendments, a strong agreement was reached for 100% of the recommendations. Of these recommendations, 6 have a high level of evidence (Grade 1 ± ), 6 have a low level of evidence (Grade 2 ± ) and 5 are experts' opinions. No recommendation could be provided for 3 questions.

CONCLUSIONS

Substantial agreement exists among experts regarding many strong recommendations for paediatric airway management.

Parallel substrate supply and pH stabilization for optimal screening of E. coli with the membrane-based fed-batch shake flask

Background

Screening in the fed-batch operation mode is essential for biological cultivations facing challenges as oxygen limitation, osmotic inhibition, catabolite repression, substrate inhibition or overflow metabolism. As a screening tool on shake flask level, the membrane-based fed-batch shake flask was developed. While a controlled supply of a substrate was realized with the in-built membrane tip, the possibilities for replenishing nutrients and stabilizing pH values was not yet exploited. High buffer concentrations were initially used, shifting the medium osmolality out of the biological optimum. As the growth rate is predefined by the glucose release kinetics from the reservoir, the resulting medium acidification can be compensated with a controlled continuous supply of an alkaline compound. The focus of this research is to establish a simultaneous multi-component release of glucose and an alkaline compound from the reservoir to enable cultivations within the optimal physiological range of Escherichia coli.

Results

In combination with the Respiratory Activity MOnitoring System, the membrane-based fed-batch shake flask enabled the detection of an ammonium limitation. The multi-component release of ammonium carbonate along with glucose from the reservoir resulted not only in the replenishment of the nitrogen source but also in the stabilization of the pH value in the culture medium. A biomass concentration up to 25 g/L was achieved, which is one of the highest values obtained so far to the best of the author’s knowledge with the utilization of a shake flask and a defined synthetic medium. Going a step further, the pH stabilization allowed the decrease of the required buffer amount to one-fourth establishing an optimal osmolality range for cultivation. As optimal physiological conditions were implemented with the multi-component release fed-batch cultivation, the supply of 0.2 g glucose in a 10 mL initial culture medium volume with 50 mM MOPS buffer resulted in a twofold higher biomass concentration than in a comparable batch cultivation.

Conclusions

The newly introduced multi-component release with the membrane-based fed-batch shake flask serves a threefold purpose of replenishing depleted substrates in the culture medium, stabilizing the pH throughout the entire cultivation time and minimizing the necessary amount of buffer to maintain an optimal osmolality range. In comparison to a batch cultivation, these settings enable to achieve higher biomass and product concentrations.

Electronic supplementary material

The online version of this article (10.1186/s12934-018-0917-8) contains supplementary material, which is available to authorized users.

Systematic evaluation of characteristics of the membrane-based fed-batch shake flask

BACKGROUND

The initial part of process development involves extensive screening programs to identify optimal biological systems and cultivation conditions. For a successful scale-up, the operation mode on screening and production scale must be as close as possible. To enable screening under fed-batch conditions, the membrane-based fed-batch shake flask was developed. It is a shake flask mounted with a central feed reservoir with an integrated rotating membrane tip for a controlled substrate release. Building on the previously provided proof of principle for this tool, this work extends its application by constructive modifications and improved methodology to ensure reproducible performance.

RESULTS

The previously limited operation window was expanded by a systematic analysis of reservoir set-up variations for cultivations with the fast-growing organism Escherichia coli. Modifying the initial glucose concentration in the reservoir as well as interchanging the built-in membrane, resulted in glucose release rates and oxygen transfer rate levels during the fed-batch phase varying up to a factor of five. The range of utilizable membranes was extended from dialysis membranes to porous microfiltration membranes with the design of an appropriate membrane tip. The alteration of the membrane area, molecular weight cut-off and liquid volume in the reservoir offered additional parameters to fine-tune the duration of the initial batch phase, the oxygen transfer rate level of the fed-batch phase and the duration of feeding. It was shown that a homogeneous composition of the reservoir without a concentration gradient is ensured up to an initial glucose concentration of 750 g/L. Finally, the experimental validity of fed-batch shake flask cultivations was verified with comparable results obtained in a parallel fed-batch cultivation in a laboratory-scale stirred tank reactor.

CONCLUSIONS

The membrane-based fed-batch shake flask is a reliable tool for small-scale screening under fed-batch conditions filling the gap between microtiter plates and scaled-down stirred tank reactors. The implemented reservoir system offers various set-up possibilities, which provide a wide range of process settings for diverse biological systems. As a screening tool, it accurately reflects the cultivation conditions in a fed-batch stirred tank reactor and enables a more efficient bioprocess development.

Autoimmune hemolytic anemia in systemic lupus erythematosus at diagnosis: differences between pediatric and adult patients

Objective To determine the overall prevalence of autoimmune hemolytic anemia (AIHA), and to compare clinical and laboratory features in a large population of children and adult lupus patients at diagnosis. Methods This retrospective study evaluated the medical charts of 336 childhood-onset systemic lupus erythematosus (cSLE) and 1830 adult SLE (aSLE) patients followed in the same tertiary hospital. Demographic data, clinical features and disease activity were recorded. AIHA was defined according to the presence of anemia (hemoglobin <10 g/dL) and evidence of hemolysis (reticulocytosis and positive direct antiglobulin test (DAT)/Coombs test) at SLE diagnosis. Evans syndrome (ES) was defined by the combination of immune thrombocytopenia (platelet count <100,000/mm³) and AIHA. Results The frequency of AIHA at diagnosis was significantly higher in cSLE patients compared to aSLE (49/336 (14%) vs 49/1830 (3%), p = 0.0001), with similar frequency of ES (3/336 (0.9%) vs 10/1830 (0.5%), p = 0.438). The median of hemoglobin levels was reduced in cSLE vs aSLE patients (8.3 (2.2-10) vs 9.5 (6.6-10) g/dL, p = 0.002) with a higher frequency of multiple hemorrhagic manifestations (41% vs 7%, p = 0.041) and erythrocyte transfusion due to bleeding (24% vs 5%, p = 0.025). cSLE patients also had more often constitutional involvement (84% vs 31%, p < 0.001), fever (65% vs 26%, p < 0.001), weight loss > 2 kg (39% vs 6%, p < 0.001), reticuloendothelial manifestations (48% vs 8%, p < 0.001), hepatomegaly (25% vs 2%, p < 0.001) and splenomegaly (21% vs 2%, p = 0.004). Other major organ involvements were common but with similar frequencies in cSLE and aSLE ( p > 0.05). Median systemic lupus erythematosus disease activity index 2000 (SLEDAI-2 K) was comparable in cSLE and aSLE (p = 0.161). Conclusions We identified that AIHA was not a common condition in cSLE and aSLE, with distinct features characterized by a higher prevalence/severity in children and concomitant constitutional symptoms in the majority of them.

Kinase dynamics. Using ancient protein kinases to unravel a modern cancer drug's mechanism

Macromolecular function is rooted in energy landscapes, where sequence determines not a single structure but an ensemble of conformations. Hence, evolution modifies a protein's function by altering its energy landscape. Here, we recreate the evolutionary pathway between two modern human oncogenes, Src and Abl, by reconstructing their common ancestors. Our evolutionary reconstruction combined with x-ray structures of the common ancestor and pre-steady-state kinetics reveals a detailed atomistic mechanism for selectivity of the successful cancer drug Gleevec. Gleevec affinity is gained during the evolutionary trajectory toward Abl and lost toward Src, primarily by shifting an induced-fit equilibrium that is also disrupted in the clinical T315I resistance mutation. This work reveals the mechanism of Gleevec specificity while offering insights into how energy landscapes evolve.

[Lipid and fatty acid profiles of Pseudomonas aurantiaca DNA-bound lipids determined by mass spectrometry]

An approach used on investigation of the lipid composition of loosely (fraction 1) and tightly (fraction 2) DNA-bound lipids of Pseudomonas aurantiaca cells by electrospray ionization using mass spectrometry (ESI-LC-MS) was used for determination of the lipidom of a prokaryotic cell. Free fatty acids C16:0, C18:1 (fraction 1), C14:0, C16:0, and C18:2 (fraction 2) were detected. Both fractions of DNA-bound lipids were characterized by the presence of phosphatidylglycerol, phosphatidylserine, and lyso-phosphatidylinositol. The alcohol-soluble fraction 1 could also contain phosphatidylcholine and phosphatidylinositol, while fraction 2 probably contained triacylglycerides. Compared to gas chromatography, ESI-LC-MS provides new possibilities for investigation of the nucleoid lipidome, providing for more detailed investigation of DNA-bound lipids in bacterial cells.

An ADARPEF survey on respiratory management in pediatric anesthesia

BACKGROUND

There have been recent changes with regard to tools and concepts for respiratory management of children undergoing general anesthesia.

OBJECTIVES

To determine the practice of pediatric anesthetists concerning: preoxygenation, breathing systems, ventilation modes, anesthetic agent and airway device, strategies for a general anaesthetic of less than 30 min using spontaneous respiration, and opinion about technical aspects of ventilation.

METHODS

Online questionnaire sent by e-mail to all the anesthetists registered on the mailing list of the French-speaking Pediatric Anesthetists and Intensivists Association (ADARPEF).

RESULTS

232 questionnaires (46%) were returned. More than 25% of anesthetists surveyed declared that they do not perform preoxygenation before induction for children <15 years old, apart from neonates and clinical specific situations. When performed, <65% chose a FiO2 higher than 80%. Inhalational induction with sevoflurane is the preferred mode of induction set at 6% or 8%, respectively, 69% [62-75] vs 25% [18-31]. For induction, the circle system was the most popular circuit used in all ages. The accessory breathing system-Mapleson B type-was predominantly used for neonates (44% [37-54]). For maintenance of an anesthesia lasting <30 min in spontaneous breathing, the use of laryngeal mask increased with age, and the endotracheal tube was reserved for neonates (40% [33-48]). Pressure support ventilation was rarely used from the beginning of induction but was widely used for maintenance, whatever the age-group. Results differed according to the type of institution.

CONCLUSION

Ventilation management depends on the age and institutions in terms of circuit, airway device or ventilation mode, and specific differences exist for neonates.