Recording of a left ventricle assist device electrical current with a neurally adjusted ventilation assist (NAVA) catheter: a small case series.

BACKGROUND: Neurally Adjusted Ventilatory Assist (NAVA) is an adaptive ventilation mode that recognizes electromyographic diaphragmatic activation as a sensory input to control the ventilator. NAVA may be of interest in prolonged mechanical ventilation and weaning, as it provides effort-adapted support, improves patient-ventilator synchronization, and allows additional monitoring of neuromuscular function and drive. Ventricular assist devices (VAD), especially for the left ventricle (LVAD), are increasingly entering clinical practice, and intensivists are faced with distinct challenges such as the interaction between the system and other measures of organ support. CASE PRESENTATION: We present two cases in which a NAVA mode was intended to support ventilator weaning in patients with recent LVAD implantation (HeartMate III®). However, in these patients, the electrical activity of the diaphragm (Edi) could not be used to control the ventilator, because the LVAD current detected by the catheter superposed the Edi current, making usage of this mode impossible. DISCUSSION/CONCLUSIONS: An implanted LVAD can render the NAVA signal unusable for ventilatory support because the LVAD signal can interfere with the recording of electromyographic activation of the diaphragm. Therefore, patients with implanted LVAD may need other modes of ventilation than NAVA for advanced weaning strategies.

Central venous catheter contamination rate in suspected sepsis patients: an observational clinical study.

BACKGROUND: More than 160,000 central-line-associated bloodstream infections (CLABSIs) are estimated for Europe each year, leading to about 25,000 deaths. AIM: To characterize the contamination of administration sets in suspected CLABSI cases in the intensive care unit (ICU). METHODS: In ICU patients (from February 2017 to February 2018) with suspected CLABSI, all sampled central venous catheters (CVCs) were examined in four segments (from CVC tip to connected tubing systems) for contamination. A risk factor analysis using binary logistic regression was performed. FINDINGS: Fifty-two consecutively sampled CVCs with 1004 elements were analysed with 45 elements being positive for at least one micro-organism (4.48%). There was a significant association with the duration of catheterization (P = 0.038, N = 50) with a daily increase of contamination risk by 11.5% (odds ratio: 1.115). The mean number of CVC manipulations was 40 within 72 h (standard deviation: 20.5), with no association with contamination risk (P = 0.381). The contamination risk of the CVC segments decreased from proximal to distal. Non-replaceable components of the CVC had a high risk (14 times higher; P = 0.01). A significant positive correlation was detected between positive tip cultures and microbial growth in the administration set (r(49) = 0.437; P = 0.001). CONCLUSION: Although only a minority of CLABSI-suspect patients had positive blood cultures, the contamination rate of CVCs and administration set was high, possibly indicating a relevant underreporting. The finding of identical species in adjacent segments underlines the role of upward or downward spread of micro-organisms within the tubes; therefore, aseptic tasks should be emphasized.

Point-of-care detection of lactate in cerebrospinal fluid.

PURPOSE: Measurements of cerebrospinal fluid (CSF) lactate can aid in detecting infections of the central nervous system and surrounding structures. Neurosurgical patients with temporary lumbar or ventricular CSF drainage harbor an increased risk for developing infections of the central nervous system, which require immediate therapeutic responses. Since blood gas analyzers enable rapid blood-lactate measurements, we were interested in finding out if we can reliably measure CSF-lactate by this point-of-care technique. METHODS: Neurosurgical patients on our intensive care unit (ICU) with either lumbar or external ventricular drainage due to a variety of reasons were included in this prospective observational study. Standard of care included measurements of leucocyte counts, total protein and lactate measurements in CSF by the neurochemical laboratory of our University Medical Center twice a week. With respect to this study, we additionally performed nearly daily measurements of cerebrospinal fluid by blood gas analyzers to determine the reliability of CSF-lactate measured by blood gas analyzers as compared to the standard measurements with a certified device. RESULTS: 62 patients were included in this study. We performed 514 CSF-lactate measurements with blood gas analyzers and compared 180 of these to the in-house standard CSF-lactate measurements. Both techniques correlated highly significantly (Pearson correlation index 0.94) even though lacking full concordance in a Bland-Altman plotting. Of particular importance, regular measurements enabled immediate detection of central infection in three patients who had developed meningitis during the course of their treatment. CONCLUSION: Blood gas analyzers measure CSF-lactate with sufficient reliability and can help in the timely detection of a developing meningitis. In addition to and triggering established CSF diagnostics, CSF-lactate measurements by blood gas analyzers may improve surveillance of patients with CSF drainage. This study was retrospectively registered on April 20th 2020 in the German trial register. The trial registration number is DRKS00021466.

Monitoring lung impedance changes during long-term ventilator-induced lung injury ventilation using electrical impedance tomography.

OBJECTIVE: The target of this methodological evaluation was the feasibility of long-term monitoring of changes in lung conditions by time-difference electrical impedance tomography (tdEIT). In contrast to ventilation monitoring by tdEIT, the monitoring of end-expiratory (EELIC) or end-inspiratory (EILIC) lung impedance change always requires a reference measurement. APPROACH: To determine the stability of the used Pulmovista 500® EIT system, as a prerequisite it was initially secured on a resistive phantom for 50 h. By comparing the slopes of EELIC for the whole lung area up to 48 h from 36 pigs ventilated at six positive end-expiratory pressure (PEEP) levels from 0 to 18 cmH2O we found a good agreement (range of r 2 = 0.93-1.0) between absolute EIT (aEIT) and tdEIT values. This justified the usage of tdEIT with its superior local resolution compared to aEIT for long-term determination of EELIC. MAIN RESULTS: The EELIC was between -0.07 Ωm day-1 at PEEP 4 and -1.04 Ωm day-1 at PEEP 18 cmH2O. The complex local time pattern for EELIC was roughly quantified by the new parameter, centre of end-expiratory change (CoEEC), in equivalence to the established centre of ventilation (CoV). The ventrally located mean of the CoV was fairly constant in the range of 42%-46% of thorax diameter; however, on the contrary, the CoEEC shifted from about 40% to about 75% in the dorsal direction for PEEP levels of 14 and 18 cmH2O. SIGNIFICANCE: The observed shifts started earlier for higher PEEP levels. Changes of EELI could be precisely monitored over a period of 48 h by tdEIT on pigs.

Noninvasive Neurally Adjusted Ventilator Assist Ventilation in the Postoperative Period Produces Better Patient-Ventilator Synchrony but Not Comfort.

BACKGROUND: Noninvasive neurally adjusted ventilatory assist (NAVA) has been shown to improve patient-ventilator interaction in many settings. There is still scarce data with regard to postoperative patients indicated for noninvasive ventilation (NIV) which this study elates. The purpose of this trial was to evaluate postoperative patients for synchrony and comfort in noninvasive pressure support ventilation (NIV-PSV) vs. NIV-NAVA. METHODS: Twenty-two subjects received either NIV-NAVA or NIV-PSV in an object-blind, prospective, randomized, crossover fashion (observational trial). We evaluated blood gases and ventilator tracings throughout as well as comfort of ventilation at the end of each ventilation phase. RESULTS: There was an effective reduction in ventilator delays (p < 0.001) and negative pressure duration in NIV-NAVA as compared to NIV-PSV (p < 0.001). Although we used optimized settings in NIV-PSV, explaining the overall low incidence of asynchrony, NIV-NAVA led to reductions in the NeuroSync-index (p < 0.001) and all types of asynchrony except for double triggering that was significantly more frequent in NIV-NAVA vs. NIV-PSV (p = 0.02); ineffective efforts were reduced to zero by use of NIV-NAVA. In our population of previously lung-healthy subjects, we did not find differences in blood gases and patient comfort between the two modes. CONCLUSION: In the postoperative setting, NIV-NAVA is well suitable for use and effective in reducing asynchronies as well as a surrogate for work of breathing. Although increased synchrony was not transferred into an increased comfort, there was an advantage with regard to patient-ventilator interaction. The trial was registered at the German clinical Trials Register (DRKS no.: DRKS00005408).

Preemptive veno-venous ECMO support in a patient with anticipated difficult airway: A case report.

This report presents a case of endotracheal metastasis in which elective veno-venous extracorporeal membrane oxygenation (VV ECMO) was used to undergo tracheal laser-surgery prior to establishment of a definitive airway. Specifically, we describe the respiratory and airway management in an adult patient from the preclinical phase throughout elective preoperative ECMO implantation to postoperative ECMO weaning and decannulation in the Intensive Care Unit. This case report lends further supports to the idea that the extracorporeal membrane oxygenation could be electively used to provide safe environment for surgery in situations where the standard maneuvers of sustaining adequate gas exchange are anticipated to fail.

[Prolonged Weaning - S2k-Guideline Published by the German Respiratory Society]. / Prolongiertes Weaning.

Mechanical ventilation (MV) is an essential part of modern intensive care medicine. MV is performed in patients with severe respiratory failure caused by insufficiency of respiratory muscles and/or lung parenchymal disease when/after other treatments, (i. e. medication, oxygen, secretion management, continuous positive airway pressure or nasal highflow) have failed.MV is required to maintain gas exchange and to buy time for curative therapy of the underlying cause of respiratory failure. In the majority of patients weaning from MV is routine and causes no special problems. However, about 20 % of patients need ongoing MV despite resolution of the conditions which precipitated the need for MV. Approximately 40 - 50 % of time spent on MV is required to liberate the patient from the ventilator, a process called "weaning."There are numberous factors besides the acute respiratory failure that have an impact on duration and success rate of the weaning process such as age, comorbidities and conditions and complications acquired in the ICU. According to an international consensus conference "prolonged weaning" is defined as weaning process of patients who have failed at least three weaning attempts or require more than 7 days of weaning after the first spontaneous breathing trial (SBT). Prolonged weaning is a challenge, therefore, an inter- and multi-disciplinary approach is essential for a weaning success.In specialised weaning centers about 50 % of patients with initial weaning failure can be liberated from MV after prolonged weaning. However, heterogeneity of patients with prolonged weaning precludes direct comparisons of individual centers. Patients with persistant weaning failure either die during the weaning process or are discharged home or to a long term care facility with ongoing MV.Urged by the growing importance of prolonged weaning, this Sk2-guideline was first published in 2014 on the initiative of the German Respiratory Society (DGP) together with other scientific societies involved in prolonged weaning. Current research and study results, registry data and experience in daily practice made the revision of this guideline necessary.The following topics are dealt with in the guideline: Definitions, epidemiology, weaning categories, the underlying pathophysiology, prevention of prolonged weaning, treatment strategies in prolonged weaning, the weaning unit, discharge from hospital on MV and recommendations for end of life decisions.Special emphasis in the revision of the guideline was laid on the following topics:- A new classification of subgroups of patients in prolonged weaning- Important aspects of pneumological rehabilitation and neurorehabilitation in prolonged weaning- Infrastructure and process organization in the care of patients in prolonged weaning in the sense of a continuous treatment concept- Therapeutic goal change and communication with relativesAspects of pediatric weaning are given separately within the individual chapters.The main aim of the revised guideline is to summarize current evidence and also expert based- knowledge on the topic of "prolonged weaning" and, based on the evidence and the experience of experts, make recommendations with regard to "prolonged weaning" not only in the field of acute medicine but also for chronic critical care.Important addressees of this guideline are Intensivists, Pneumologists, Anesthesiologists, Internists, Cardiologists, Surgeons, Neurologists, Pediatricians, Geriatricians, Palliative care clinicians, Rehabilitation physicians, Nurses in intensive and chronic care, Physiotherapists, Respiratory therapists, Speech therapists, Medical service of health insurance and associated ventilator manufacturers.

A spiky pattern in the course of electrical thoracic impedance as a very early sign of a developing pneumothorax.

A pneumothorax (PTX) is a potentially lethal condition in high-risk intensive care patients. Electrical impedance tomography (EIT) has been proven to detect PTX at the bedside. A so far not described pattern in the course of thoracic impedance at an early state of PTX was observed in a pig model of ventilator-induced lung injury (VILI) used for a more extensive study. EIT was performed at a framerate of 50 Hz. Beginning of PTX at normal ventilation, manifestation of PTX at VILI ventilation (plateau pressure 42 cm H2 O) and final pleural drainage were documented. At ventilation with 8·6 ml kg-1 , early PTX findings prior to any clinical deterioration consisted in a spike-like pattern in the time course of impedance (relative impedance change referred to initial end-expiratory level). Spike amplitudes (mean ± SD) were the following: 0·154 ± 0·059 (right lung) and 0·048 ± 0·050 (left lung). At this state, end-expiratory levels (mean ± SD) were still similar, -0·035 ± 0·010 (right) and -0·058 ± 0·022 (left). After application of VILI ventilation (38 ml kg-1 ), a PTX developed slowly, being confirmed by a continuous increase in the end-expiratory level on the right side and diverging levels of +0·320 ± 0·057 (right) and -0·193 ± 0·147 (left) at full manifestation. We assume that spikes reflect a temporary change in the electrical pathway caused by leakage into the pleural cavity. This newly described phenomenon of spikes is considered to be a potentially useful indicator for a very early detection of an evolving PTX in high-risk ICU patients.

[Cost analysis as a tool for assessing the efficacy of intensive care units]. / Kosten als Instrument zur Effizienzbeurteilung intensivmedizinischer Funktionseinheiten.

BACKGROUND: The German "Hospital Structure Act" intends to align the state hospital planning on quality criteria. Within this process cost-utility analyses (CUAs) shall be used to assess the efficacy of medical care. To be objective, CUAs of intensive care units (ICUs) require standardization (adjustment) of costs. The present study analyzed the extent to which treatment costs are related to patient-specific baseline variables (such as type and severity of the primary disease). METHODS: From 2000-2004, a bottom-up procedure was used to quantify total costs on 14 ICUs in nine German university hospitals. Results were combined with demographic data, and data indicating type (ICD-10 codes) and severity (ICU scoring systems) of the primary disease at ICU admission. Various statistical models were tested to identify that which best described the associations between baseline variables and costs. RESULTS: In all, 3803 critically ill patients could be examined. The median of treatment costs per patient was 3199 € (IQR 1768-6659 €). No model allowed an acceptably precise adjustment of costs; the estimated mean absolute prognostic error was at least 3860 € (mean relative prognostic error 66%), when we tested an Extreme Gradient Boosting Model. CONCLUSION: Instruments which are currently available (cost adjustment based on patient-specific baseline variables) do not allow a standardization of costs, and an objective CUA of ICUs. Factors unknown at baseline may cause a large portion of treatment costs.

Sequential use of extracorporeal devices to avoid mechanical ventilation in a patient with complicated pulmonary fibrosis.

Extracorporeal lung assist devices are widely used these days for a growing number of indications. We report the case of a patient managed with three different flow-range devices sequentially, enabling us to avoid mechanical ventilation. Handling and ethics of this approach are discussed.

Ventilator-related causes of lung injury: the mechanical power.

PURPOSE: We hypothesized that the ventilator-related causes of lung injury may be unified in a single variable: the mechanical power. We assessed whether the mechanical power measured by the pressure-volume loops can be computed from its components: tidal volume (TV)/driving pressure (∆P aw), flow, positive end-expiratory pressure (PEEP), and respiratory rate (RR). If so, the relative contributions of each variable to the mechanical power can be estimated. METHODS: We computed the mechanical power by multiplying each component of the equation of motion by the variation of volume and RR: [Formula: see text]where ∆V is the tidal volume, ELrs is the elastance of the respiratory system, I:E is the inspiratory-to-expiratory time ratio, and R aw is the airway resistance. In 30 patients with normal lungs and in 50 ARDS patients, mechanical power was computed via the power equation and measured from the dynamic pressure-volume curve at 5 and 15 cmH2O PEEP and 6, 8, 10, and 12 ml/kg TV. We then computed the effects of the individual component variables on the mechanical power. RESULTS: Computed and measured mechanical powers were similar at 5 and 15 cmH2O PEEP both in normal subjects and in ARDS patients (slopes = 0.96, 1.06, 1.01, 1.12 respectively, R (2) > 0.96 and p < 0.0001 for all). The mechanical power increases exponentially with TV, ∆P aw, and flow (exponent = 2) as well as with RR (exponent = 1.4) and linearly with PEEP. CONCLUSIONS: The mechanical power equation may help estimate the contribution of the different ventilator-related causes of lung injury and of their variations. The equation can be easily implemented in every ventilator's software.

[Implementation of a rational standard of hygiene for preparation of operating rooms]. / Implementierung eines rationalen Hygienestandards zur Aufbereitung von Operationssälen.

BACKGROUND: The assurance of high standards of care is a major requirement in German hospitals while cost reduction and efficient use of resources are mandatory. These requirements are particularly evident in the high-risk and cost-intensive operating theatre field with multiple process steps. The cleaning of operating rooms (OR) between surgical procedures is of major relevance for patient safety and requires time and human resources. The hygiene procedure plan for OR cleaning between operations at the university hospital in Göttingen was revised and optimized according to the plan-do-check-act principle due to not clearly defined specifications of responsibilities, use of resources, prolonged process times and increased staff engagement. METHODS: The current status was evaluated in 2012 as part of the first step "plan". The subsequent step "do" included an expert symposium with external consultants, interdisciplinary consensus conferences with an actualization of the former hygiene procedure plan and the implementation process. All staff members involved were integrated into this management change process. The penetration rate of the training and information measures as well as the acceptance and compliance with the new hygiene procedure plan were reviewed within step "check". The rates of positive swabs and air sampling as well as of postoperative wound infections were analyzed for quality control and no evidence for a reduced effectiveness of the new hygiene plan was found. After the successful implementation of these measures the next improvement cycle ("act") was performed in 2014 which led to a simplification of the hygiene plan by reduction of the number of defined cleaning and disinfection programs for preparation of the OR. RESULTS: The reorganization measures described led to a comprehensive commitment of the hygiene procedure plan by distinct specifications for responsibilities, for the course of action and for the use of resources. Furthermore, a simplification of the plan, a rational staff assignment and reduced process times were accomplished. Finally, potential conflicts due to an insufficient evidence-based knowledge of personnel was reduced. CONCLUSION: This present project description can be used by other hospitals as a guideline for similar changes in management processes.

S2k-Guideline "Prolonged Weaning".

All mechanically ventilated patients must be weaned from the ventilator at some stage. According to an International Consensus Conference the criteria for "prolonged weaning" are fulfilled if patients fail at least 3 weaning attempts (i. e. spontaneous breathing trial, SBT) or require more than 7 days of weaning after the first SBT. This occurs in about 15 - 20 % of patients.Because of the growing number of patients requiring prolonged weaning a German guideline on prolonged weaning has been developed. It is an initiative of the German Respiratory Society (Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin e. V., DGP) in cooperation with other societies (see acknowledgement) engaged in the field chaired by the Association of Scientific and Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF).This guideline deals with the definition, epidemiology, weaning categories, underlying pathophysiology, therapeutic strategies, the weaning unit, transition to out-of-hospital ventilation and therapeutic recommendations for end of life care. This short version summarises recommendations on prolonged weaning from the German guideline.

[Prolonged weaning: S2k-guideline published by the German Respiratory Society]. / Prolongiertes Weaning: S2k-Leitlinie herausgegeben von der Deutschen Gesellschaftfür Pneumologie und Beatmungsmedizin e.V.

Mechanical ventilation (MV) is an essential part of modern intensive care medicine. MV is performed in patients with severe respiratory failure caused by insufficiency of the respiratory muscles and/or lung parenchymal disease when/after other treatments, i. e. oxygen, body position, secretion management, medication or non invasive ventilation have failed.In the majority of ICU patients weaning is routine and does not present any problems. Nevertheless 40-50 % of the time during mechanical ventilation is spent on weaning. About 20 % of patients need continued MV despite resolution of the conditions which originally precipitated the need for MV.There maybe a combination of reasons; chronic lung disease, comorbidities, age and conditions acquired in ICU (critical care neuromyopathy, psychological problems). According to an International Consensus Conference the criteria for "prolonged weaning" are fulfilled if patients fail at least three weaning attempts or require more than 7 days of weaning after the first spontaneous breathing trial. Prolonged weaning is a challenge. An inter- and multi-disciplinary approach is essential for weaning success. Complex, difficult to wean patients who fulfill the criteria for "prolonged weaning" can still be successfully weaned in specialised weaning units in about 50% of cases.In patients with unsuccessful weaning, invasive mechanical ventilation has to be arranged either at home or in a long term care facility.This S2-guideline was developed because of the growing number of patients requiring prolonged weaning. It is an initiative of the German Respiratory Society (Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin e. V., DGP) in cooperation with other societies engaged in the field.The guideline is based on a systematic literature review of other guidelines, the Cochrane Library and PubMed.The consensus project was chaired by the Association of Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF) based on a formal interdisciplinary process applying the Delphi-concept. The guideline covers the following topics: Definitions, epidemiology, weaning categories, pathophysiology, the spectrum of treatment strategies, the weaning unit, discharge from hospital on MV and recommendations for end of life decisions. Special issues relating to paediatric patients were considered at the end of each chapter.The target audience for this guideline are intensivists, pneumologists, anesthesiologists, internists, cardiologists, surgeons, neurologists, pediatricians, geriatricians, palliative care clinicians, nurses, physiotherapists, respiratory therapists, ventilator manufacturers.The aim of the guideline is to disseminate current knowledge about prolonged weaning to all interested parties. Because there is a lack of clinical research data in this field the guideline is mainly based on expert opinion.

Hypoglycaemia and predisposing factors among clinical subgroups treated with intensive insulin therapy.

BACKGROUND: In previous studies, conflicting intensive insulin therapy (IIT) results have been observed, whereby IIT-related mortality seems to be lower in specific clinical subgroups. The aim of this study was to assess differences in glycaemic control, the risk of critical hypoglycaemia (≤ 2.2 mmol/l), the associated predisposing factors, and the in-hospital mortality in different clinical subgroups treated with IIT. METHODS: Prospective, observational study in a university-affiliated intensive care unit (ICU) conducted from 2004 to 2005. All patients (n = 1667) belonging to one of the six most common surgical intervention groups (cardiac, neuro, abdominal, vascular, orthopaedic, and spinal surgeries) and medical patients were included. IIT was performed with a target blood glucose level of 4.4-7.8 mmol/l. Different indices were analysed to evaluate glucose control and glycaemic variability. RESULTS: The rate of critical hypoglycaemia was significantly different within the different clinical subgroups and varied from 0.8% to 4.5%. Similar results were obtained for hyperglycaemia. Multivariable analyses for the predisposing factors of critical hypoglycaemia showed a heterogeneous distribution pattern among the different clinical subgroups. Similar results were obtained for the risk factors of in-hospital mortality. CONCLUSION: The risk of critical hypoglycaemia and the associated predisposing factors depended on the clinical subgroup involved. Critical hypoglycaemia is a potential threat for our patients, and the high risk of critical hypoglycaemia in some clinical subgroups appeared to reverse the benefits of IIT. As a result, it is crucial that the different subgroups involved in a study are defined to further interpret the potential benefits of IIT and the risk of critical hypoglycaemia.

A systematic technical review of the systems for the continuous positive airway pressure.

Continuous positive airway pressure (CPAP) is the application in the airways of continuous positive pressure, close to the positive end expiratory pressure. The two common available systems are by a continuous (high/low) flow system and by a mechanical ventilator. Aim of this study was to compare the mechanical performance of the CPAP systems in intubated and not intubated patients. Medical literature databases (MEDLINE and EMBASE) were searched for articles on "clinical trials" and "randomized controlled trials". The key words "continuous positive airway pressure" and "CPAP", were combined with any of these key words: adult, work of breathing, continuous flow, mechanical valve, water valve, balloon reservoir, mechanical ventilator, pressure triggering, flow triggering, lung model, demand valve, equipment. Thirty-two articles (18 human and 14 bench studies) met the inclusion criteria. The continuous flow systems are able to maintain acceptable airway pressure variations during normal breathing. The most recent mechanical ventilators equipped with flow by systems compared to the first one, presented a similar or better work of breathing compared to the continuous flow systems due to the application of a little amount of pressure support. Although the use of a continuous flow is cheaper compared to mechanical ventilators, it does not allow a continuous respiratory monitoring.

Neurally adjusted ventilatory assist vs. pressure support ventilation in critically ill patients: an observational study.

BACKGROUND: During neurally adjusted ventilatory assist (NAVA), the inspiratory support is controlled by the patients' respiratory drive influenced by an operator-controlled gain factor (NAVA level). The purpose of our observational study was to transfer patients from conventional pressure support ventilation (PSV) to NAVA safely. We compared two approaches to set the NAVA level and evaluated the effect of NAVA. METHODS: We studied mechanically ventilated patients capable of spontaneous breathing. For the change of the ventilator mode, we used a NAVA level calculated to generate a peak inspiratory pressure equal to PSV. We compared this NAVA level with a NAVA level determined by a NAVA level titration. Ventilatory and haemodynamic data were recorded during an observational period of 6 h. RESULTS: All 20 patients included in the study could be transferred from PSV to NAVA and completed the observation interval. Setting the NAVA level according to prior PSV settings proved to be a feasible approach, but in 75% of our patients, we modified the NAVA level according to the titration results. Gas exchange and ventilatory mechanics during the observation interval remained stable. CONCLUSIONS: The ventilator mode NAVA seems to be well tolerated in a heterogeneous group of critically ill patients. Pre-setting of the NAVA level during PSV can result in an overestimation of the required ventilator support. An additional titration of the NAVA level ads valuable information although difficult to interpret in some cases.

Protective and ultra-protective ventilation: using pumpless interventional lung assist (iLA).

Acute lung failure is associated with high mortality and usually requires mechanical ventilation to ensure adequate gas exchange. However, mechanical ventilation itself can be associated with major complications and can aggravate pre-existing lung disease, thus contributing to morbidity and mortality. Extracorporeal gas exchange is increasingly used when conventional mechanical ventilation has failed. In contrast to veno-venous extracorporeal membrane oxygenation (ECMO), pumpless extracorporeal interventional lung assist (iLA) is applied via an arterio-venous bypass into which a gas exchange membrane is integrated. iLA allows for efficient carbon dioxide removal, which allows for a significant reduction in ventilator settings. iLA may be a useful tool in protective or even 'ultraprotective' ventilation, enabling the application of very low tidal volumes in patients with acute respiratory failure of different etiologies. This article reviews the current status and the potential role of interventional (pumpless) lung-assist iLA within the context of lung-protective ventilation strategies.

[Extraglottic airway devices in the intensive care unit]. / Extraglottische Atemwegshilfen auf der Intensivstation.

Extraglottic airway devices (EGA) are not only used in routine anaesthesia practice, they also have a distinct value for in-hospital and out-of-hospital difficult airway management. In the environment of the intensive care unit (ICU) EGA are not used on a regular basis. However, expertise and knowledge regarding EGA coming from the operating theatre or the out-of-hospital setting may also be of value for the ICU setting. This review presents the potential indications for EGA on the ICU for the management of difficult airway situations as well as during percutaneous tracheotomy. Furthermore, the possible advantages of EGA during postoperative recovery from anaesthesia as well as termination of controlled ventilation for intensive care patients are discussed.