Efficiency of passive activated carbon anaesthetic gas capturing systems during simulated ventilation.

BACKGROUND: Interest in passive flow filter systems to remove sevoflurane from anaesthetic machine exhaust have increased recently to mitigate the environmental impact of volatile anaesthetics. These filter systems consist of chemically activated carbon, with limited evidence on their performance characteristics. We hypothesised that their efficiency depends on filter material. METHODS: Binding capacity was tested for three carbon filter materials (CONTRAfluran®, FlurAbsorb®, and Anaesthetic Agent Filter AAF633). Adsorption efficiency and resistive pressure were determined during simulated ventilation at different stages of filter saturation and fresh gas flow. In addition, sevoflurane concentration in filtered gas was measured at randomly selected anaesthesia workstations. RESULTS: Sevoflurane concentration in filtered gas exceeded 10 ppm when saturated with 184 ml sevoflurane each for CONTRAfluran and FlurAbsorb and 276 ml for AAF633. During simulated ventilation, sevoflurane concentration >10 ppm passed through CONTRAfluran and AAF633 at fresh gas flow 10 L min-1 only at maximum saturation, but through FlurAbsorb at all stages of saturation. The resistance pressure of all filters was negligible during simulated ventilation, but increased up to 5.2 (0.2) cm H2O during simulated coughing. At two of seven anaesthesia workstations, sevoflurane concentration in filtered exhaust gas was >10 ppm. CONCLUSIONS: Depending on the filter material and saturation, the likelihood of sevoflurane passing through passive flow carbon filters depends on the filter material and fresh gas flow. Combining the filter systems with anaesthetic gas scavenging systems could protect from pollution of ambient air with sevoflurane.

Comparison of Force Distribution during Laryngoscopy with the C-MAC D-BLADE and Macintosh-Style Blades: A Randomised Controlled Clinical Trial.

Background: The geometry of a laryngoscope's blade determines the forces acting on the pharyngeal structures to a relevant degree. Knowledge about the force distribution along the blade may prospectively allow for the development of less traumatic blades. Therefore, we examined the forces along the blades experienced during laryngoscopy with the C-MAC D-BLADE and blades of the Macintosh style. We hypothesised that lower peak forces are applied to the patient's pharyngeal tissue during videolaryngoscopy with a C-MAC D-BLADE compared to videolaryngoscopy with a C-MAC Macintosh-style blade and direct laryngoscopy with a Macintosh-style blade. Beyond that, we assumed that the distribution of forces along the blade differs depending on the respective blade's geometry. Methods: After ethical approval, videolaryngoscopy with the D-BLADE or the Macintosh blade, or direct laryngoscopy with the Macintosh blade (all KARL STORZ, Tuttlingen, Germany), was performed on 164 randomly assigned patients. Forces were measured at six positions along each blade and compared with regard to mean force, peak force and spatial distribution. Furthermore, the duration of the laryngoscopy was measured. Results: Mean forces (all p < 0.011) and peak forces at each sensor position (all p < 0.019) were the lowest with the D-BLADE, whereas there were no differences between videolaryngoscopy and direct laryngoscopy with the Macintosh blades (all p > 0.128). With the D-BLADE, the forces were highest at the blade's tip. In contrast, the forces were more evenly distributed along the Macintosh blades. Videolaryngoscopy took the longest with the D-BLADE (p = 0.007). Conclusions: Laryngoscopy with the D-BLADE resulted in significantly lower forces acting on pharyngeal and laryngeal tissue compared to Macintosh-style blades. Interestingly, with the Macintosh blades, we found no advantage for videolaryngoscopy in terms of force application.

Health Literacy of Children and Adolescents with Inflammatory Bowel Disease (IBD) and Parents of IBD Patients-Coping and Information Needs.

BACKGROUND: The number of children and adolescents with inflammatory bowel disease (IBD) is increasing. Many chronically ill children and adolescents have low health literacy. Patient empowerment (PE) enables positive changes and control over one's disease through specific activities, information, and counseling. The CEDNA (IBD Needs Assessment) Survey aimed to provide the necessary data to improve PE in pediatric IBD (PIBD). METHODS: Questionnaires were distributed to adolescent IBD patients and parents of children and adolescents with IBD throughout Germany. The answers were given anonymously. Based on the available data, a subgroup analysis was conducted in relation to the age of the patients and the period since diagnosis. For the parents' responses, the same age groups were analyzed for comparison with the patients' responses. RESULTS: From October 2021 to April 2022, 2810 questionnaires were distributed and 1158 questionnaires were completed (n = 708 parents [61.1%], n = 450 patients [38.9%]). The results indicate that health literacy in children with IBD is low. Significant gaps in knowledge of important IBD topics were identified, and a comparison of responses regarding preferred methods and timing of obtaining information revealed differences between patient and parent preferences. The greatest need for knowledge on IBD topics was found in the group of 16-17-year-old patients on transition (n = 214, 31.8%) and in the group of patients diagnosed 1-2 years ago on the causes of IBD (n = 288, 17.4%). The willingness to seek advice was unexpectedly low. CONCLUSIONS: The analysis of all findings according to the patient's age structure and duration since diagnosis can be used to enable age-appropriate communication at certain stages of the disease. This tailored information should increase patients' health literacy, improve their management of the disease, and reduce the burden on their families.

Effective volume of rebreathed air during breathing with facepieces increases with protection class and decreases with ambient airflow.

Wearing facepieces is discussed in the context of increasing the volume of rebreathed air. We hypothesized that rebreathed air volume increases with increasing filtering facepiece (FFP) class and that persons breathing via facepieces compensate for the additional dead-space. We have determined the effective amount of rebreathed air for a surgical masks and FFP2 and FFP3 respirators in a physical model and determined tidal volumes, breathing frequency, blood oxygen saturation, and transcutaneously measured blood carbon dioxide partial pressure (PCO2) in lung-healthy subjects breathing without and with facepieces at rest and during exercising on a recumbent ergometer. Rebreathed air volume increased with the facepieces' protection class and with increasing inspiration volume by 45 ± 2 ml to 247 ± 1 ml. Ambient airflow reduced rebreathed air volume by 17% up to 100% (all p < 0.001). When wearing facepieces, subjects increased tidal volume (p < 0.001) but not breathing frequency. Oxygen saturation was not influenced by facepieces. With FFP3 respirators PCO2 increased by up to 3.2 mmHg (p < 0.001) at rest but only up to 1.4 mmHg (p < 0.001) when exercising. Discomfort of breathing increased with increasing protection class of the facepiece but was consistently perceived as tolerable. We conclude that the amount of rebreathed air increases with increasing protection class of facepieces. Healthy adults were capable to compensate the facepieces' dead-space by adapting tidal volume at rest and during physical activity; thereby they tolerated moderate increases in PCO2. Ambient airflow may considerably reduce the amount of facepiece related rebreathed air.

Comparative usability of manual defibrillators - A human factors study.

Background: A manual defibrillator represents key equipment for resuscitation of cardiac arrest scenario. Improper or slow operation of a defibrillator may adversely affect acute care. A self-explanatory interface facilitates handling and decreases the risk of operating errors. Therefore, we evaluated the usability of four commercially available defibrillators. Methods: 31 medical students executed 15 consecutive tasks on each defibrillator (Physio-Control Lifepak 20e, Schiller Defigard Touch 7, Corpuls 3 and Zoll X-Series). The operators' gaze was measured via eye-tracking and frequencies of required assistances and task completion times were recorded. Additionally, subjective perception of usability was assessed by a standardized questionnaire. Results: Least assistances (16) were required when operating the Lifepak 20e and most (63) when operating the X-Series. Cumulative task completion times were shortest in the Lifepak 20e (124 ± 31 s), followed by the Corpuls 3 (220 ± 69 s), the Defigard Touch 7 (225 ± 81 s) and the X-Series (289 ± 85 s; p < 0.001). Completion times of specific tasks differed considerably between the devices. Eye-tracking revealed associated interface issues that impeded the operators' performance. Overall standardized usability was rated best for the Lifepak 20e (81 ± 15) and worst for the X-Series (44 ± 20). Conclusions: The usability of defibrillators differs considerably and task specifically between devices. Interface issues of tasks impaired the operators' efficiency specifically. The perceived usability and the perceived stress-level after operating the devices corresponded with objective measures of usability. Eliminating specific usability issues may improve the operator's performance and, as a consequence patient outcome.

Calculating intrinsic positive end-expiratory pressure from end-expiratory flow in mechanically ventilated children-A study in physical models of the pediatric respiratory system.

RATIONALE: The high resistance of pediatric endotracheal tubes (ETTs) exposes mechanically ventilated children to a particular risk of developing intrinsic positive end-expiratory pressure (iPEEP). To date, determining iPEEP at the bedside requires the execution of special maneuvers, interruption of ventilation, or additional invasive measurements. Outside such interventions, iPEEP may be unrecognized. OBJECTIVE: To develop a new approach for continuous calculation of iPEEP based on routinely measured end-expiratory flow and ETT resistance. METHODS: First, the resistance of pediatric ETTs with inner diameter from 2.0 to 4.5 mm were empirically determined. Second, during simulated ventilation, iPEEP was either calculated from the measured end-expiratory flow and ETT's resistance (iPEEPcalc ) or determined with a hold-maneuver available at the ventilator (iPEEPhold ). Both estimates were compared with the end-expiratory pressure measured at the ETT's tip (iPEEPdirect ) by means of absolute deviations. RESULTS: End-expiratory flow and iPEEP increased with decreasing ETT inner diameter and with higher respiratory rates. iPEEPcalc and iPEEPhold were comparable and indicated good correspondence with iPEEPdirect . The largest absolute mean deviation was 1.0 cm H2 O for iPEEPcalc and 1.1 cm H2 O for iPEEPhold . CONCLUSION: We conclude that iPEEP can be determined from routinely measured variables and predetermined ETT resistance, which has to be confirmed in the clinical settings. As long as this algorithm is not available in pediatric ICU ventilators, nomograms are provided for estimating the prevailing iPEEP from end-expiratory flow.

A Nationwide Survey on Patient Empowerment in Pediatric Inflammatory Bowel Disease in Germany.

BACKGROUND: The incidence/prevalence of pediatric inflammatory bowel disease (IBD) is increasing. IBD places a significant burden on young patients during important developmental stages and affects their families. Children and adolescents with IBD require increased support from health care services. However, little is known about the additional support needed and how to provide it. Therefore, a large survey was conducted with a focus on patient empowerment. METHODS: For the anonymous survey, called CEDNA, a patient questionnaire for adolescents with IBD and a questionnaire for parents of children and adolescents with IBD were made available throughout Germany (distributed n = 2810). Questions covered various aspects of coping with the disease, utilization of care, use and need of information and communication services, and how information should be provided. RESULTS: From October 2021 to April 2022, 1158 (n = 708 parents (61.1%), n = 450 patients (38.9%)) questionnaires were completed. The results show a deficit in pediatric IBD care and revealed a large gap in knowledge about core IBD topics (e.g., 74.8% of patients feel poorly informed about transition, 62.4% know little about patient organizations and self-help groups, and 54.7% have little information about preventive health measures), indicating a low level of health literacy among affected children and adolescents. CONCLUSION: Pediatric IBD poses significant challenges for patients, their families, and healthcare teams. By empowering patients and families, and providing targeted information and communication tailored to the age of the child or adolescent and the needs of the parents, care can be improved and better adapted to the needs of patients. Actions would include providing quality information online through scientific societies and patient organizations and facilitating self-management in adolescents.

Healthcare service use in paediatric inflammatory bowel disease: a questionnaire on patient and parent care experiences in Germany.

BACKGROUND: Paediatric inflammatory bowel disease (PIBD) patients require chronic care over the lifespan. Care for these patients is complex, as it is adapted for childrens' life stages and changing disease activity. Guideline based care for this patient group recommends a multidisciplinary approach, which includes in addition to paediatric gastroenterologists, nutritional and psychological care services. For PIBD patients, a discrepancy between available guideline-based multidisciplinary care and actual care has been found from the provider side, but to what extent patients experience this is unclear. OBJECTIVES: To identify which healthcare services were used and whether socio-demographic, geographic or disease related factors have an influence on health service utilisation. METHODS: A standardised questionnaire (CEDNA) was distributed amongst parents of children aged 0-17 diagnosed with PIBD and adolescents (aged 12-17) with a PIBD. Items related to health service use were analysed, these included specialist care, additional care services, reachability of services and satisfaction with care. Logistic regression models on additional service use were calculated. Service availability and reachability maps were made. RESULTS: Data was analysed for 583 parent and 359 adolescent questionnaires. Over half of the respondents had Crohn's Disease (CD, patients n = 186 parents n = 297). Most patients and parents reported their paediatric gastroenterologist as their main care contact (patients 90.5%; parents 93%). Frequently reported additional services were nutritional counselling (patients 48.6%; parents 42.2%) and psychological support (patients 28.1%; parents 25.1%). Nutritional counselling was more frequently reported by CD patients in both the patient (OR 2.86; 95%CI 1.73-4.70) and parent (OR 3.1; 95%CI 1.42-6.71) sample. Of the patients, 32% reported not using any additional services, which was more likely for patients with an illness duration of less than one year (OR 3.42; 95%CI 1.26-9.24). This was also observed for the parent population (OR 2.23; 95%CI 1.13-4.4). The population-based density of specialised paediatric gastroenterologists was not proportionate to the spatial distribution of patients in Germany, which may have an influence on access. CONCLUSIONS: Parents and children reported highly specialised medical care. Multidisciplinary care offers do not reach the entire patient population. Access to multidisciplinary services needs to be ensured for all affected children.

Establishment and validation of intravenous anesthesia with dexmedetomidine for pigs under assisted spontaneous breathing: A preclinical model of intensive care conditions.

Large animal models are frequently used to investigate new medical approaches. In most cases, animals are kept under general anesthesia and mandatory mechanical ventilation during the experiments. However, in some situations assisted spontaneous breathing is essential, e.g. when simulating conditions in a modern intensive care unit. Therefore, we established an anesthesia regime with dexmedetomidine and midazolam/ketamine in porcine models of assisted spontaneous breathing. The total intravenous anesthesia was used in lung healthy pigs, in pigs with oleic acid induced acute respiratory distress syndrome and in pigs with methacholine induced bronchopulmonary obstruction. We were able to maintain stable conditions of assisted spontaneous breathing without impairment of hemodynamic, respiratory or blood gas variables in lung healthy pigs and pigs with induced acute respiratory distress syndrome for a period of five hours and in pigs with induced bronchopulmonary obstruction for three hours. Total intravenous anesthesia containing dexmedetomidine enables stable conditions of assisted spontaneous breathing in healthy pigs, in pigs with induced acute respiratory distress syndrome and in pigs induced bronchopulmonary obstruction as models of intensive care unit conditions.

Quantification of regional CMRO2 in human brain using dynamic 17O-MRI at 3T.

OBJECTIVE: To investigate the feasibility of cerebral metabolic rate of oxygen consumption (CMRO2) measurements with MRI at 3 Tesla in different brain regions. METHODS: CMRO2 represents a key indicator of the physiological state of brain tissue. Dynamic 17O-MRI with inhalation of isotopically enriched 17O gas has been used to quantify global CMRO2 in brain white (WM) and gray matter (GM). However, global CMRO2 can only reflect the overall oxygen metabolism of the brain and cannot provide enough information on local tissue oxygen metabolism. To investigate the feasibility of determination of regional CMRO2 at a clinical 3 T MRI system, CMRO2 values in frontal, parietal and occipital WM and GM were determined in 5 healthy volunteers and compared to evaluate the regional differences of oxygen metabolism in WM and GM. Additionally, regional CMRO2 values were determined in deep brain structures including thalamus, dorsal striatum, caudate nucleus and insula cortex and in the cerebella, and compared with literature values from 15O-PET studies. RESULTS: In cortical GM the determined CMRO2 values were in good agreement with the literature, whereas values in WM were about 32-48% higher than literature values. Regional analysis revealed a significantly higher CMRO2 in the occipital GM compared to the frontal and parietal GM. By contrast, no significant difference of CMRO2 was observed across the WM. In addition, CMRO2 in deep brain structures was lower compared to literature values and in the cerebella a good hemispheric symmetry of the tissue oxygen metabolism was found. CONCLUSION: Dynamic 17O-MRI enables direct, non-invasive determination of regional CMRO2 in brain structures in healthy volunteers at 3T.

Postpyloric nutrition to prevent emergencies - a step away from repeat inpatient care in children with methylmalonic acidaemia and propionic acidaemia - a case report of four cases.

Methylmalonic acidaemia (MMA) and propionic acidaemia (PA) are very rare autosomal recessive inherited metabolic diseases from the group of organoacidopathies. Katabolism due to minor infections can lead to metabolic decompensation including hyperammonemia and ketoacidosis, especially in small children. We present data from a small cohort to clarify whether placement of a percutaneous endoscopic gastrostomy with jejunal tube (J-PEG) reduce metabolic imbalances and hospital stays. The aim is to prevent emergencies from occurring by preventing metabolic derailments at an early stage. 4 patients with MMA (N = 3) or PA (N = 1) were included. Data were collected at every investigation, in particular pH value, pCO2, bicarbonate, base excess, ammonia and lactate. Due to repeated metabolic derailments, a percutaneous endoscopic gastrostomy was placed for postpyloric nutrition. In conclusion, placement of a percutaneous endoscopic gastrostomy with postpyloric tube appears to reduce the rate of metabolic decompensations. In addition, hospital stays and especially the number of treatment days can be reduced. This method, especially the placement of a postpyloric tube could enable parents to prevent catabolism when vomiting begins by continuously feeding through the jejunal part, as a step to prevent a metabolic emergency from occurring.

Constipation in Children and Adolescents.

BACKGROUND: According to a population-based study, approximately 6.8% of children and adolescents in Germany suffer from acute or chronic constipation. It can be of organic or functional origin and may be associated with comorbid disturbances, particularly fecal incontinence. METHODS: We selectively searched the PubMed and Google Scholar databases for articles with the keywords "constipation," "children and adolescents," and "incontinence". Recommendations are based on the AWMF guideline on constipation and fecal incontinence and on international guidelines and reviews. RESULTS: More than 90% of cases of chronic constipation are of functional origin. Organic causes vary with age and call for targeted differential diagnosis. Invasive tests are only rarely necessary. Functional constipation may be associated with fecal and urinary incontinence, and the relative risk of urinary tract infections is 2.2 to 6.5. There may be associated psychological symptoms and mental disorders in 30-50% of cases. The cornerstone of treatment is patient and parent education, along with laxative medication and toilet training. Instructional programs have been found effective in otherwise refractory cases. CONCLUSION: The treatment of constipation in childhood should begin as soon as the differential diagnostic evaluation is completed. The education of parents, follow-up at close intervals, and drug treatment and behavioral therapy that are adapted to the symptoms can improve quality of life.

Intratidal compliance of the lung and the total respiratory system.

Objective.The worldwide rising quantity of surgeries and the corresponding need of mechanical ventilation means a rising number of patients are at risk of suffering from post-operative pulmonary complications. To prevent this risk, individual mechanics of the lung should be considered when setting the parameters of mechanical ventilation. Intratidal compliance analysis based on transpulmonal pressure would provide an estimate for individual lung mechanics. The downside of such measure, however, is its invasiveness. Accurate measurement requires recording of the esophageal pressure as surrogate for the actual pleural pressure. Measuring pressure at the airway opening is considerably easier, but the resulting mechanics of the respiratory system may not represent the actual lung mechanics in a straightforward fashion.Approach.In order to evaluate if the mechanics of the lungs are represented by analysis of the mechanics of the respiratory system we determined intratidal dynamic compliance-volume profiles of both in 23 lung-healthy mechanically ventilated patients undergoing elective surgery. We also compared the accuracy of the compliance profiles resulting from analysis of the total breath with those resulting from the analysis of inspiration data only.Main results.When the whole breath was analyzed 54.3%, and with only inspiration data 69.6%, of compliance profiles of the respiratory system matched those of the lung. With both approaches profiles of the lung and the respiratory system matched or deviated by only one neighboring step (75% whole breath, 91.3% inspiration only), and never contradicted each other.Significance.Compliance profiles calculated from volume and pressure data of the respiratory system are an adequate surrogate for the compliance profiles of the lungs of lung-healthy patients. Therefore, invasive assessment of esophageal pressure for achievement of intrapleural pressure is unnecessary. The compliance profiles based on only inspiratory data appear more sensitive for indicating intratidal derecruitment than those based on data of the whole breath.

Lung area estimation using functional tidal electrical impedance variation images and active contouring.

Objective.Electrical impedance tomography is a valuable tool for monitoring global and regional lung mechanics. To evaluate the recorded data, an accurate estimate of the lung area is crucial.Approach.We present two novel methods for estimating the lung area using functional tidal images or active contouring methods. A convolutional neural network was trained to determine, whether or not the heart region was visible within tidal images. In addition, the effects of lung area mirroring were investigated. The performance of the methods and the effects of mirroring were evaluated via a score based on the impedance magnitudes and their standard deviations in functional tidal images.Main results.Our analyses showed that the method based on functional tidal images provided the best estimate of the lung area. Mirroring of the lung area had an impact on the accuracy of area estimation for both methods. The achieved accuracy of the neural network's classification was 94%. For images without a visible heart area, the subtraction of a heart template proved to be a pragmatic approach with good results.Significance.In summary, we developed a routine for estimation of the lung area combined with estimation of the heart area in electrical impedance tomography images.

Profiling Distinctive Inflammatory and Redox Responses to Hydrogen Sulfide in Stretched and Stimulated Lung Cells.

Hydrogen sulfide (H2S) protects against stretch-induced lung injury. However, the impact of H2S on individual cells or their crosstalk upon stretch remains unclear. Therefore, we addressed this issue in vitro using relevant lung cells. We have explored (i) the anti-inflammatory properties of H2S on epithelial (A549 and BEAS-2B), macrophage (RAW264.7) and endothelial (HUVEC) cells subjected to cycling mechanical stretch; (ii) the intercellular transduction of inflammation by co-culturing epithelial cells and macrophages (A549 and RAW264.7); (iii) the effect of H2S on neutrophils (Hoxb8) in transmigration (co-culture setup with HUVECs) and chemotaxis experiments. In stretched epithelial cells (A549, BEAS-2B), the release of interleukin-8 was not prevented by H2S treatment. However, H2S reduced macrophage inflammatory protein-2 (MIP-2) release from unstretched macrophages (RAW264.7) co-cultured with stretched epithelial cells. In stretched macrophages, H2S prevented MIP-2 release by limiting nicotinamide adenine dinucleotide phosphate oxidase-derived superoxide radicals (ROS). In endothelial cells (HUVEC), H2S inhibited interleukin-8 release and preserved endothelial integrity. In neutrophils (Hoxb8), H2S limited MIP-2-induced transmigration through endothelial monolayers, ROS formation and their chemotactic movement. H2S induces anti-inflammatory effects in a cell-type specific manner. H2S limits stretch- and/or paracrine-induced inflammatory response in endothelial, macrophage, and neutrophil cells by maintaining redox homeostasis as underlying mechanism.

Biosensor-Enabled Multiplexed On-Site Therapeutic Drug Monitoring of Antibiotics.

Personalized antibiotherapy ensures that the antibiotic concentration remains in the optimal therapeutic window to maximize efficacy, minimize side effects, and avoid the emergence of drug resistance due to insufficient dosing. However, such individualized schemes need frequent sampling to tailor the blood antibiotic concentrations. To optimally integrate therapeutic drug monitoring (TDM) into the clinical workflow, antibiotic levels can either be measured in blood using point-of-care testing (POCT), or can rely on noninvasive sampling. Here, a versatile biosensor with an antibody-free assay for on-site TDM is presented. The platform is evaluated with an animal study, where antibiotic concentrations are quantified in different matrices including whole blood, plasma, urine, saliva, and exhaled breath condensate (EBC). The clearance and the temporal evaluation of antibiotic levels in EBC and plasma are demonstrated. Influence of matrix effects on measured drug concentrations is determined by comparing the plasma levels with those in noninvasive samples. The system's potential for blood-based POCT is further illustrated by tracking ß-lactam concentrations in untreated blood samples. Finally, multiplexing capabilities are explored successfully for multianalyte/sample analysis. By enabling a rapid, low-cost, sample-independent, and multiplexed on-site TDM, this system can shift the paradigm of "one-size-fits-all" strategy.

Understanding pediatric ventilation in the operative setting. Part II: Setting perioperative ventilation.

Approaches toward lung-protective ventilation have increasingly been investigated in recent years. Despite evidence being found in adults undergoing surgery, data in younger children are still scarce and controversial. From a physiological perspective, however, the continuously changing characteristics of the respiratory system from birth through adolescence require an approach based on the analysis of each individual patient. The modern anesthesia workstation provides such information, with the technical strengths and weaknesses being discussed in a review preceding the present work (see Part I). The present summary aims to provide ideas on how to translate the information displayed on the anesthesia workstation to patient-oriented clinical ventilation settings.

Trigger performance of five pediatric home ventilators and one ICU ventilator depending on circuit type and system leak in a physical model of the lung.

BACKGROUND: The population of children with chronic respiratory failure requiring long-term mechanical ventilation in the home has grown worldwide. The optimal choice from an increasing number of home ventilators commercialized for children is often challenging for the attending physicians. The aim of the present study was to compare the trigger performance of five pediatric bilevel home ventilators and one intensive care unit ventilator depending on circuit type and system leak. METHODS: The trigger performances of the ventilators were compared in combination with all compatible circuits using a physical model of the lung with increasing system leak. The flow generator simulated the patient's breathing effort with flow rates of 2.7-6.4 L/min at a frequency of 30 breaths/min. All ventilators were set to deliver 16 cmH2 O inspiratory pressure support and 4 cmH2 O positive end-expiratory pressure. RESULTS: Trigger thresholds varied from 1.5 to 8 L/min, the pressure rise time to 90% of the maximum from 140 to 385 ms and the trigger work from 0.5 to 6.6 mbar · s. All devices had very short trigger delays below 40 ms. The leak compensation depended on the circuit type. The internal diameter of the circuit had no relevant impact on the trigger performance or the leak compensation. CONCLUSION: We observed considerable differences in the triggering performance of the evaluated home ventilators depending on leak size and type of circuit. Therefore, an optimal combination of device and circuit should consider the patient's age and condition and the probability of system leak.

Understanding pediatric ventilation in the operative setting. Part I: Physical principles of monitoring in the modern anesthesia workstation.

The modern anesthesia workstation provides a wealth of information some of which is of particular interest when it comes to optimizing ventilation settings. This knowledge gains even more importance in the therapy of pediatric patients. In the absence of evidence-based recommendations on optimal ventilation settings in pediatric patients, the evaluation of individual factors becomes crucial and challenging at the same time. Even when equipped with the latest sensor technology, the user will always have to be in charge of interpreting the provided monitoring variables. The purpose of this review is to outline the clinical impact, technological background, and reliability of the most relevant information measured and calculated by a modern anesthesia workstation. It aims at translating the technical knowledge into a more competent and vigilant application in the clinical setting.