An Exploratory Study of Sevoflurane as an Alternative for Difficult Sedation in Critically Ill Children

Volatile gas scavenging in the paediatric intensive care unit: Occupational health and safety assessment

Introduction

The use of volatile anesthetic agents in the paediatric intensive care unit (PICU) is experiencing increased interest since the availability of the miniature vapourizing device. However, the effectiveness of scavenging systems in the presence of humidifiers in the ventilator circuit is unknown.

Approach Methods

We performed a bench study to evaluate the effectiveness of the Deltasorb® scavenging system in the presence of isoflurane and active humidity by simulating both infant and child ventilator test settings. A total of four ventilators were set to ventilate test lungs, all with active humidity and a Deltasorb scavenging canister collecting exhaled ventilation gas. Two ventilators also had isoflurane delivered using the Anesthesia Conserving Device- small (ACD®-S) on the inspiratory limb (also called alternative ventilator configuration). We performed instantaneous measurements of isoflurane and continuous sampling with passive badges to measure average environmental exposure over a test period of 6.5 hours. Scavenging canisters were returned to the company, where desorption analysis showed the volume of water and isoflurane captured in each canister.

Findings

Both instantaneous point sampling and diffusive sampling results were below the occupational exposure limit confirming safety. The canisters collected both isoflurane and a portion of the water vapour delivered; the percentage of captured water and isoflurane collected in infants was higher than the child ventilator test settings.

Practice implications Conclusion

The tested scavenging configuration was effective in maintaining a safe working environment with active humidity and inspiratory limb (alternative) ventilator configuration of the the miniature vapourizing device.

Analgesia and sedation in critically ill pediatric patients: an update from the recent guidelines and point of view

In the last decades, the advancement of knowledge in analgesia and sedation for critically ill pediatric patients has been conspicuous and relevant. Many recommendations have changed to ensure patients' comfort during their intensive care unit (ICU) stay and prevent and treat sedation-related complications, as well as improve functional recovery and clinical outcomes. The key aspects of the analgosedation management in pediatrics have been recently reviewed in two consensus-based documents. However, there remains a lot to be researched and understood. With this narrative review and authors' point of view, we aimed to summarize the new insights presented in these two documents to facilitate their interpretation and application in clinical practice, as well as to outline research priorities in the field.    Conclusion: With this narrative review and authors' point of view, we aimed to summarize the new insights presented in these two documents to facilitate their interpretation and application in clinical practice, as well as to outline research priorities in the field. What is Known: • Critically ill pediatric patients receiving intensive care required analgesia and sedation to attenuate painful and stressful stimuli. •Optimal management of analgosedation is a challenge often burdened with complications such as tolerance, iatrogenic withdrawal syndrome, delirium, and possible adverse outcomes. What is New: •The new insights on the analgosedation treatment for critically ill pediatric patients delineated in the recent guidelines are summarized to identify strategies for changes in clinical practice. •Research gaps and potential for quality improvement projects are also highlighted.

Is ketamine infusion effective and safe as an adjuvant of sedation in the PICU? Results from the Ketamine Infusion Sedation Study (KISS)

STUDY OBJECTIVE

We aimed to evaluate the efficacy and safety of ketamine in ensuring comfort and sparing conventional drugs when used as an adjuvant for analgesia and sedation in the Pediatric Intensive Care Unit (PICU) as a continuous infusion (≥12 h).

DESIGN

Observational prospective study.

SETTING

Tertiary-care-center PICU.

PATIENTS

All consecutive patients <18 years who received ketamine for ≥12 h between January 2019 and July 2021.

INTERVENTIONS

ketamine infusion for ≥12 h.

MEASUREMENTS AND MAIN RESULTS

Seventy-seven patients (median age 16 months, Interquartile Range (IQR) 7-43) were enrolled. Twenty-six percent of patients (n = 20) were paralyzed, while 74% (n = 57) were not. The median infusion duration was 90 h (IQR 39-193), with doses between 15 (IQR 15-20) and 30 μg/kg/min (IQR 20-50). At 24 h of ketamine infusion, values of COMFORT-B-Scale (CBS) were significantly lower compared with values pre-ketamine (p < 0.001). Simultaneously, doses/kg/h of opioids and benzodiazepines significantly decreased at 24 h (p < 0.001 and p = 0.002, respectively), while doses/kg/h of propofol (p = 0.500) and dexmedetomidine (p = 0.072) did not significantly change. Seventy-four percent of non-paralyzed patients (42/57) had a decrease in CBS ≥2 points with no increase of concomitant analgosedation drugs. Among paralyzed patients (n = 20), 13 (65%) had no increase of concomitant analgosedation within 24 h after ketamine initiation. Overall, 55/77 (71%) of patients responded to ketamine. The mean and maximum ketamine infusion dosages were significantly higher in the non-responders (p = 0.021 and 0.028, respectively). Eleven patients had adverse events potentially related to ketamine (hypersalivation, systemic hypertension, dystonia/dyskinesia, tachycardia, and agitation) and six patients required intervention (dose reduction, suspension, or pharmacologic therapy). None of the patients developed delirium during ketamine infusion.

CONCLUSIONS

Ketamine used as a continuous infusion in the PICU might represent a valid strategy to ensure comfort and spare opioids and benzodiazepines in difficult-to-sedate PICU patients. Adverse events are minor and easily reversible. Future study will be needed to investigate long-term outcomes.

Malignant Hyperthermia in PICU—From Diagnosis to Treatment in the Light of Up-to-Date Knowledge

Malignant Hyperthermia (MH) is a rare, hereditary, life-threatening disease triggered by volatile anesthetics and succinylcholine. Rarely, MH can occur after non-pharmacological triggers too. MH was detected more often in children and young adults, which makes this topic very important for every pediatric specialist, both anesthesiologists and intensivists. MH crisis is a life-threatening severe hypermetabolic whole-body reaction. Triggers of MH are used in pediatric intensive care unit (PICU) as well, volatile anesthetics in difficult sedation, status asthmaticus or epilepticus, and succinylcholine still sometimes in airway management. Recrudescence or delayed onset of MH crisis hours after anesthesia was previously described. MH can also be a cause of rhabdomyolysis and hyperpyrexia in the PICU. In addition, patients with neuromuscular diseases are often admitted to PICU and they might be at risk for MH. The most typical symptoms of MH are hypercapnia, tachycardia, hyperthermia, and muscle rigidity. Thinking of the MH as the possible cause of deterioration of a patient’s clinical condition is the key to early diagnosis and treatment. The sooner the correct treatment is commenced, the better patient´s outcome. This narrative review article aims to summarize current knowledge and guidelines about recognition, treatment, and further management of MH in PICU.

50% effective concentration of sevoflurane for immobility in cerebral palsy children undergoing botulinum toxin injection

BACKGROUND

This prospective study aimed to determine the optimum end-tidal sevoflurane concentration required for immobility during botulinum toxin injection in spontaneously breathing children with cerebral palsy (CP).

METHODS

Twenty-three children with spastic CP, aged 3 to 12 years, with American Society of Anesthesiologists (ASA) physical status I and II, scheduled to receive botulinum toxin type A injection were enrolled in the study. After induction of deep sedation using pre-filled 8% sevoflurane in oxygen and maintenance of the predetermined end-tidal sevoflurane concentration, the botulinum toxin was injected in spontaneously breathing children. The response to the botulinum toxin injection was classified as "movement" or "no movement" by an independent investigator who was blinded to the predetermined end-tidal sevoflurane concentration and bispectral index (BIS) value. The end-tidal sevoflurane concentration was predetermined, initiating at 2.0% with 0.2% as a step size in the next patient depending on the previous patient's response using the modified Dixon's up-and-down method.

RESULTS

Of 21 children, 12 (57.1%) showed "no movement" in response to the botulinum toxin injection. By Dixon's up-and-down method, the 50% effective end-tidal concentration (EC50) of sevoflurane for successful botulinum toxin injection was 1.76 ± 0.15% (95% CI 1.62-1.90). Based on the dose-response curve using probit analysis, the predicted EC50 and 95% effective end-tidal concentrations (EC95) of sevoflurane without movement were 1.77% (95% CI 1.59-2.35) and 2.09% (95% CI 1.89-5.80), respectively.

CONCLUSION

Botulinum toxin injection can be successfully accomplished at an end-tidal sevoflurane concentration of 1.76 ± 0.15% in 50% of spontaneously breathing children with CP aged 3-12 years.

Pain and sedation management and monitoring in pediatric intensive care units across Europe: an ESPNIC survey

BACKGROUND

Management and monitoring of pain and sedation to reduce discomfort as well as side effects, such as over- and under-sedation, withdrawal syndrome and delirium, is an integral part of pediatric intensive care practice. However, the current state of management and monitoring of analgosedation across European pediatric intensive care units (PICUs) remains unknown. The aim of this survey was to describe current practices across European PICUs regarding the management and monitoring of pain and sedation.

METHODS

An online survey was distributed among 357 European PICUs assessing demographic features, drug choices and dosing, as well as usage of instruments for monitoring pain and sedation. We also compared low- and high-volume PICUs practices. Responses were collected from January to April 2021.

RESULTS

A total of 215 (60% response rate) PICUs from 27 European countries responded. Seventy-one percent of PICUs stated to use protocols for analgosedation management, more frequently in high-volume PICUs (77% vs 63%, p = 0.028). First-choice drug combination was an opioid with a benzodiazepine, namely fentanyl (51%) and midazolam (71%) being the preferred drugs. The starting doses differed between PICUs from 0.1 to 5 mcg/kg/h for fentanyl, and 0.01 to 0.5 mg/kg/h for midazolam. Daily assessment and documentation for pain (81%) and sedation (87%) was reported by most of the PICUs, using the preferred validated FLACC scale (54%) and the COMFORT Behavioural scale (48%), respectively. Both analgesia and sedation were mainly monitored by nurses (92% and 84%, respectively). Eighty-six percent of the responding PICUs stated to use neuromuscular blocking agents in some scenarios. Monitoring of paralysed patients was preferably done by observation of vital signs with electronic devices support.

CONCLUSIONS

This survey provides an overview of current analgosedation practices among European PICUs. Drugs of choice, dosing and assessment strategies were shown to differ widely. Further research and development of evidence-based guidelines for optimal drug dosing and analgosedation assessment are needed.

Intensive care nurses' experiences using volatile anaesthetics in the intensive care unit: An exploratory study

OBJECTIVE

To explore the experiences intensive care nurses have with volatile anaesthetics in the intensive care unit.

RESEARCH METHODOLOGY AND DESIGN

A qualitative exploratory and descriptive design was used. Data were collected in 2019 from individual interviews with nine intensive care nurses, who were recruited using purposive sampling. Data were analysed using systematic text condensation.

SETTING

The study was undertaken in two general intensive care units from different university hospitals in Norway where volatile anaesthetics were utilised.

FINDINGS

Three categories emerged from the data analysis: experiencing the benefits of volatile anaesthetics; coping with unfamiliarity in handling volatile anaesthetics; and meeting challenges related to volatile anaesthetics in practice.

CONCLUSION

The intensive care nurses had positive experiences related to administering volatile anaesthetics in the intensive care unit and responded positively to the prospect of using it more often. Because volatile anaesthetics were rarely used in their units, the participants felt uncertain regarding its use due to unfamiliarity. Collegial support and guidelines were perceived as pivotal in helping them cope with this uncertainty. The participants also experienced several challenges in using volatile anaesthetics in the intensive care unit, with ambient pollution being regarded as the main challenge.

Recommendations for analgesia and sedation in critically ill children admitted to intensive care unit

We aim to develop evidence-based recommendations for intensivists caring for children admitted to intensive care units and requiring analgesia and sedation. A panel of national paediatric intensivists expert in the field of analgesia and sedation and other specialists (a paediatrician, a neuropsychiatrist, a psychologist, a neurologist, a pharmacologist, an anaesthesiologist, two critical care nurses, a methodologist) started in 2018, a 2-year process. Three meetings and one electronic-based discussion were dedicated to the development of the recommendations (presentation of the project, selection of research questions, overview of text related to the research questions, discussion of recommendations). A telematic anonymous consultation was adopted to reach the final agreement on recommendations. A formal conflict-of-interest declaration was obtained from all the authors. Eight areas of direct interest and one additional topic were considered to identify the best available evidence and to develop the recommendations using the Evidence-to-Decision framework according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. For each recommendation, the level of evidence, the strength of the recommendation, the benefits, the harms and the risks, the benefit/harm balance, the intentional vagueness, the values judgement, the exclusions, the difference of the opinions, the knowledge gaps, and the research opportunities were reported. The panel produced 17 recommendations. Nine were evaluated as strong, 3 as moderate, and 5 as weak. Conclusion: a panel of national experts achieved consensus regarding recommendations for the best care in terms of analgesia and sedation in critically ill children.

Protective Effects of Dexmedetomidine on Hippocampal Neurons in Rats Anesthetized with Sevoflurane

To explore effects of dexmedetomidine (Dex) on cognitive function and hippocampal neuronal apoptosis in rats anesthetized with sevoflurane (Sevo), and regulation of brain-derived neurotrophic factor (BDNF) and its downstream signaling. 30 Sprague-Dawley (SD) rats were randomly divided into control group inhaled 29% concentration oxygen), Sevo group (2 L/min oxygen flow +1.5% Sevo), Dex+Sevo group (after injection of 20 μg/kg Dex, treated with 2L/min oxygen flow+1.5% Sevo). Haematoxylin and eosin (HE) staining and Nissl’s staining were adopted to detect morphological and functional changes in hippocampus of rats. Apoptosis was detected by immunofluorescence, BDNF expression was detected by immunohistochemistry. Reverse transcription PCR (RT-PCR) was conducted to detect mRNA expression of key proteins in downstream signaling of BDNF. The results showed that Sevo induced apoptosis of hippocampus neurons, while Dex improved Sevo induced apoptosis. In contrast to the control, the positive expression of BDNF in hippocampus of Sevo group was notably decreased (P < 0.05), and that of Dex+Sevo group was notably higher in contrast to Sevo group (P < 0.05). Signaling pathways of MAPK, PI3K-Akt, and Ras were predicted by String software as the downstream pathways of BDNF. RT-PCR results showed that these 3 signaling pathways were involved in Dex improving Sevo-induced cognitive impairment and hippocampal neuron apoptosis. In conclusion, Dex could improve cognitive dysfunction and hippocampal neuron apoptosis in rats induced by Sevo, and the mechanism was related to upregulation of BDNF expression and activation of pathways of MAPK, PI3K-Akt, and Ras.

TIVA versus Inhalational Agents for Pediatric Cardiac Intensive Care

The field of pediatric intensive care has come a long way, especially with the recognition that adequate sedation and analgesia form an imperative cornerstone of patient management. With various drugs available for the same, the debate continues as to which is the better: total intravenous anesthesia (TIVA) or inhalational agents. While each have their own advantages and disadvantages, in the present era of balance toward the IV agents, we should not forget the edge our volatile agents (VAs) might have in special scenarios. And ultimately as anesthesiologists, let us not forget that be it knob and dial, or syringe and plunger, our aim is to put pain to sleep and awaken a new faith to breathe.

Inhaled sedation with sevoflurane in critically ill children during extracorporeal membrane oxygenation

Sedation can be challenging in critically ill children. Inhaled anesthetics such as sevoflurane have proved to be useful in difficult or long-term sedation. However, its use in children out of the operating room is still limited and little is yet known about its use in patients undergoing ECMO with no previous reports in children. The objective is to assess the effectiveness and safety of sevoflurane during ECMO in two pediatric patients. Sedation was successfully achieved in both patients, and patients' contribution to breathing was possible even with deep sedation. There were not any side effects during sevoflurane treatment or after withdrawal.

Long-Term Inhalative Sedation in Children With Pulmonary Diseases

OBJECTIVES

To describe safety and feasibility of long-term inhalative sedation (LTIS) in children with severe respiratory diseases compared to patients with normal lung function with respect to recent studies that showed beneficial effects in adult patients with acute respiratory distress syndrome (ARDS).

DESIGN

Single-center retrospective study.

SETTING

12-bed pediatric intensive care unit (PICU) in a tertiary-care academic medical center in Germany.

PATIENTS

All patients treated in our PICU with LTIS using the AnaConDa® device between July 2011 and July 2019.

MEASUREMENTS AND MAIN RESULTS

Thirty-seven courses of LTIS in 29 patients were analyzed. LTIS was feasible in both groups, but concomitant intravenous sedatives could be reduced more rapidly in children with lung diseases. Cardiocirculatory depression requiring vasopressors was observed in all patients. However, severe side effects only rarely occured.

CONCLUSIONS

In this largest cohort of children treated with LTIS reported so far, LTIS was feasible even in children with severely impaired lung function. From our data, a prospective trial on the use of LTIS in children with ARDS seems justified. However, a thorough monitoring of cardiocirculatory side effects is mandatory.

Silencing SP1 Alleviated Sevoflurane-Induced POCD Development via Cholinergic Anti-inflammatory Pathway

Postoperative cognitive dysfunction (POCD) is a common complication induced by anesthesia or surgery, which affects the concentration, cognition and memory of patients. Sevoflurane, a clinical anesthetic, could stimulate neuro-inflammation and lead to POCD. Recent studies found that specificity protein 1 (SP1) participates in the development of neurological diseases. Our study aims to elucidate the role of SP1 in sevoflurane-induced POCD pathogenesis. We anesthetized Sprague-Dawley rats and treated the primary hippocampal neurons with sevoflurane to construct the in vivo and in vitro POCD models. Besides, the expression and regulatory mechanism of SP1 in the pathogenesis of POCD were explored. According to the results, sevoflurane anesthesia impaired the cognitive functions of rat, significantly elevated SP1 expression and inactivated the cholinergic anti-inflammatory pathway (CAP) both in vivo and in vitro. Moreover, the sevoflurane-treated rats and neurons also exhibited obvious inflammatory responses and enhanced apoptosis. Loss-of-function assay indicated that SP1 knockdown rescued the deactivation of CAP and alleviated the sevoflurane-induced neuro-inflammation and apoptosis in rat hippocampus. Generally, our study documented that the sevoflurane-induced SP1 up-regulation affected the activation of CAP, leading to the aggravated neuro-inflammation and apoptosis. This may provide a novel sight for POCD therapy.

Gamma-hydroxybutyrate: is it a feasible alternative to midazolam in long-term mechanically ventilated children?

Aim: Benzodiazepines like midazolam are commonly used for long-term sedation of critically ill children requiring mechanical ventilation. Tolerance to midazolam may occur in these patients resulting in a ceiling effect with insufficient or missing sedative response to increases of midazolam infusion or bolus application. The aim of this study was to evaluate the feasibility of a drug rotation protocol replacing continuous infusion of midazolam with gamma-hydroxybutyrate (GHB) to counteract midazolam tolerance. Methods: This retrospective, observational study was conducted in a 14-bed pediatric intensive care unit of a tertiary referral center. Thirty-three mechanically ventilated children with tolerance to midazolam who received continuous infusion of GHB were included. Success of drug rotation from midazolam to GHB was defined as adequate sedation with GHB and subsequent reduction of required doses of midazolam. Results: In our cohort, drug rotation for at least 2 days could be successfully performed in 10 out of 34 children resulting in subsequent reduction of required doses of midazolam. Drug rotation to GHB failed in 24 patients due to insufficient sedation resulting in a premature termination of the protocol. In these children, dosing of midazolam could not be reduced following drug rotation. We could not identify factors which predict success or failure of drug rotation from midazolam to GHB. Conclusions: The data from our single-center study suggest that drug rotation from midazolam to GHB may be worth trying in children with midazolam tolerance during long-term sedation, but physicians should be aware of possible treatment failure.