Aluminium release and fluid warming: provocational setting and devices at risk.

BACKGROUND: Fluid warming, recommended for fluid rates of > 500 ml h-1, is an integral part of patient temperature management strategies. Fluid warming devices using an uncoated aluminium containing heating element have been reported to liberate aluminium resulting in critical aluminium concentrations in heated fluids. We investigated saline solution (0.9%), artificially spiked with organic acids to determine the influence of fluid composition on aluminium release using the uncoated enFlow® device. Additionally, the Level1® as a high volume fluid warming device and the ThermoSens® device were investigated with artificial spiked fluid at high risk for aluminum release and a clinically used crystalloid solution. RESULTS: Saline solution spiked with lactate more than acetate, especially at a non neutral pH, led to high aluminium release. Next to the enFlow® device, aluminium release was observed for the Level1® device, but not for the coated ThermoSens®-device. CONCLUSION: Uncoated aluminium containing fluid warming devices lead to potentially toxic levels of aluminium in heated fluids, especially in fluids with non-neutral pH containing organic acids and their salts like balanced electrolyte solutions.

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).

The effectiveness of an oral opioid rescue medication algorithm for postoperative pain management compared to PCIA : A cohort analysis.

BACKGROUND: Standard protocols or algorithms are considered essential to ensure adequate analgesia. Germany has widely adopted postoperative protocols for pain management including oral opioids for rescue medication, but the effectiveness of such protocols has only been evaluated longitudinally in a before and after setting. The aim of this cohort analysis was to compare the effectiveness of an oral opioid rescue medication algorithm for postoperative management of pain to the gold standard of patient-controlled intravenous analgesia (PCIA). MATERIAL AND METHODS: This study compared cohorts of patients of two prospective observational studies undergoing elective total hip replacement. After surgery patients received piritramide to achieve a pain score of ≤3 on the numeric rating scale (NRS 0-10). A protocol was started consisting of oral long-acting oxycodone and ibuprofen (basic analgesia). Cohort 1 (C1, 126 patients) additionally received an oral opioid rescue medication (hydromorphone) when reporting pain >3 on the NRS. Cohort 2 (C2, 88 patients) was provided with an opioid by PCIA (piritramide) for opioid rescue medication. Primary endpoints were pain intensity at rest, during movement, and maximum pain intensity within the first 24 h postoperative. Secondary endpoints were opioid consumption, functional outcome and patient satisfaction with pain management. RESULTS: Pain during movement and maximum pain intensity were higher in C1 compared to C2: pain on movement median 1st-3rd quartile: 6 (3.75-8) vs. 5 (3-7), p = 0.023; maximum pain intensity: 7 (5-9) vs. 5 (3-8), p = 0.008. There were no differences in pain intensity at rest or between women and men in either group. The mean opioid consumption in all patients (combined PACU, baseline, and rescue medication; mean ± SD mg ME) was 126.6 ± 51.8 mg oral ME (median 120 (87.47-154.25) mg ME). Total opioid consumption was lower in C1 than C2 (117 ± 46 mg vs 140 ± 56 mg, p = 0.002) due to differences in rescue opioids (C1: 57 ± 37 mg ME, C2: 73 ± 43 mg ME, p = 0.006, Z = -2.730). Basic analgesia opioid use was comparable (C1: 54 ± 31 mg ME, C2: 60 ± 36 mg ME, p = 0.288, Z = -1.063). There were no differences in respect to the addition of non-opioids and reported quality of mobilization, sleep, frequency of nausea and vomiting, or general satisfaction with pain management. CONCLUSION: In this study PCIA provided a better reduction of pain intensity, when compared to a standardized protocol with oral opioid rescue medication. This effect was associated with increased opioid consumption. There were no differences in frequencies of opioid side effects. This study was a retrospective analysis of two cohorts of a major project. As with all retrospective studies, our analysis has several limitations to consider. Data can only represent the observation of clinical practice. It cannot reflect the quality of a statement of a randomized controlled trial. Observational studies do not permit conclusions on causal relationships.

[New challenges for intensive care medicine due to climate change and global warming]. / Neue intensivmedizinische Herausforderungen durch Klimawandel und globale Erderwärmung.

BACKGROUND: In the last five decades a continuous increase in the average global temperature has been recorded. Furthermore, natural disasters (e.g. heat waves, severe storms, floods and large forest fires) are becoming more frequent. The impact of global warming and climate change on health involves an increase in respiratory, cardiovascular, renal and cognitive mental diseases. Furthermore, a change in the frequency and patterns of infectious diseases can also be observed in Europe. MATERIAL AND METHODS: This article presents the most important studies that investigated diseases associated with the climate change, with special reference to those that represent a challenge for intensive care medicine. RESULTS: Currently available epidemiological data and statistical extrapolations indicate that diseases resulting from the climate change (acute infection-related respiratory and intestinal diseases, exacerbation of pre-existing pulmonary lesions, heat-related dehydration, cerebral insults and myocardial infarction) are relevant for intensive care medicine. Particular emphasis is placed on a significant increase in acute kidney damage during heat waves. A previously unknown pattern of infectious diseases necessitates new knowledge and targeted management. In some studies, persisting mental impairments were registered during heat waves and natural disasters, e.g. posttraumatic stress disorder. CONCLUSION: Intensive care medicine must be prepared for the challenges due to global warming and climate change. Slow but continuous changes (e.g. rise in temperature) as well as acute changes (e.g. heat waves and natural disasters) will induce an increased need for intensive medical care services (e.g. an increase in the need for renal replacement procedures). Intensive care physicians will need to be familiar with the diagnostics and management of diseases associated with the climate change. An initiative of the specialist societies involved would be welcomed.

Aluminium release by coated and uncoated fluid-warming devices.

The use of fluid-warming systems is recommended for infusion rates > 500 ml.h-1 to avoid peri-operative hypothermia. Some fluid-warming devices use disposable aluminium-heated plates for heat transfer, but there is no protective coating to separate the fluid from the heated aluminium surface. It is unknown if this could promote release of aluminium into infusion fluids. We investigated a coated (Fluido compact) and an uncoated (enFlow) fluid-warming device using normal saline or balanced electrolyte solution as infusion fluids, pumped through the heated disposables at flow rates of 2, 4 and 8 ml.min-1 for 60 min each. Aluminium concentrations in the fluid samples were analysed using graphite furnace atomic absorption spectrometry. With saline the coated and uncoated devices yielded aluminium concentrations below the level of quantification (< 128 µg.l-1 ). Similarly, balanced electrolyte solution in the coated device yielded aluminium concentrations < 128 µg.l-1 . However, balanced electrolyte solution in the uncoated device yielded aluminium concentrations of up to 6794 (3465-8002 [1868-7421]) µg.l-1 . Repeating this last study at a flow rate of 2 ml.min-1 resulted in quite high aluminium concentrations when the uncoated device was not heated (~1000 µg.l-1 ) and higher concentrations after the device was heated. We conclude that using uncoated aluminium plates in fluid-warming systems can lead to a risk of administering potentially harmful concentrations of aluminium when balanced crystalloid solutions are used. The mechanism is unclear, but heat is in part involved. Coating for aluminium within medical devices in direct contact with infusion fluids should be recommended.

International registry on the use of the CytoSorb® adsorber in ICU patients : Study protocol and preliminary results.

INTRODUCTION: The aim of this clinical registry is to record the use of CytoSorb® adsorber device in critically ill patients under real-life conditions. METHODS: The registry records all relevant information in the course of product use, e. g., diagnosis, comorbidities, course of the condition, treatment, concomitant medication, clinical laboratory parameters, and outcome (ClinicalTrials.gov Identifier: NCT02312024). Primary endpoint is in-hospital mortality as compared to the mortality predicted by the APACHE II and SAPS II score, respectively. RESULTS: As of January 30, 2017, 130 centers from 22 countries were participating. Data available from the start of the registry on May 18, 2015 to November 24, 2016 (122 centers; 22 countries) were analyzed, of whom 20 centers from four countries provided data for a total of 198 patients (mean age 60.3 ± 15.1 years, 135 men [68.2%]). In all, 192 (97.0%) had 1 to 5 Cytosorb® adsorber applications. Sepsis was the most common indication for CytoSorb® treatment (135 patients). Mean APACHE II score in this group was 33.1 ± 8.4 [range 15-52] with a predicted risk of death of 78%, whereas the observed mortality was 65%. There were no significant decreases in the SOFA scores after treatment (17.2 ± 4.8 [3-24]). However interleukin-6 levels were markedly reduced after treatment (median 5000 pg/ml before and 289 pg/ml after treatment, respectively). CONCLUSIONS: This third interim report demonstrates the feasibility of the registry with excellent data quality and completeness from 20 study centers. The results must be interpreted with caution, since the numbers are still small; however the disease severity is remarkably high and suggests that adsorber treatment might be used as an ultimate treatment in life-threatening situations. There were no device-associated side effects.

Intermediate care units : Recommendations on facilities and structure.

A growing number of patients with increasingly complex or specialized diseases are being treated in hospitals worldwide. The treatment requirements of some of these patients are exceeding the capacity of standard nursing units. However, the severity of these diseases or the treatment requirements for these specific clinical pictures do not always justify admission to an intensive care unit. For this reason, an increasing number of special units (intermediate care units) are being set up to offer highly specialized treatment and close monitoring, in order to fulfil an intermediate role between the standard care unit and the intensive care unit. The recommendations of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI) on the personnel, capacity, equipment and structure of these units are intended to provide the framework for the setting up and operation of intermediate care units in collaboration with experts on both an evidence-based and an expert-based basis (where scientific evidence is not available). Where only minimal or indirect evidence is available, patient safety is paramount in the formulation of the recommendation.

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.

A follow-up on Acute Pain Services in Germany compared to international survey data.

BACKGROUND: After the introduction of instruments for benchmarking, certification and a national guideline for acute pain management, the aim of this study was to describe the current structure, processes and quality of German acute pain services (APS). METHODS: All directors of German departments of anaesthesiology were invited to complete a postal questionnaire on structures und processes of acute pain management. The survey asked for staff, techniques and quality criteria, which enabled a comparison to previous data from 1999 and surveys from other countries. RESULTS: Four hundred and eight (46%) questionnaires were returned. APS have increased considerably and are now available in 81% of the hospitals, mainly anaesthesia based. However, only 45% fulfilled the minimum quality criteria, such as the assignment of personnel, the organization of patient care during nights and weekends, written protocols for postoperative pain management, regular assessments and documenting pain scores. Staff resources varied considerably, but increased compared to 1999. Two daily rounds were performed in 71%, either by physicians and nurses (42%), by physicians only (25%) or by supervised nurses (31%). Most personnel assigned to the APS shared this work along with other duties. Only 53% of the hospitals had an integrated rotation for training their specialty trainees. CONCLUSIONS: The availability of APS in Germany and other countries has increased over the last decade; however, the quality of nearly half of the APS is questionable. Against the disillusioning background of recently reported unfavourable pain-related patient outcomes, the structures, organization and quality of APS should be revisited.

Effect of body mass index in acute respiratory distress syndrome.

BACKGROUND: Obesity is associated in healthy subjects with a great reduction in functional residual capacity and with a stiffening of lung and chest wall elastance, which promote alveolar collapse and hypoxaemia. Likewise, obese patients with acute respiratory distress syndrome (ARDS) could present greater derangements of respiratory mechanics than patients of normal weight. METHODS: One hundred and one ARDS patients were enrolled. Partitioned respiratory mechanics and gas exchange were measured at 5 and 15 cm H2O of PEEP with a tidal volume of 6-8 ml kg(-1) of predicted body weight. At 5 and 45 cm H2O of PEEP, two lung computed tomography scans were performed. RESULTS: Patients were divided as follows according to BMI: normal weight (BMI≤25 kg m(-2)), overweight (BMI between 25 and 30 kg m(-2)), and obese (BMI>30 kg m(-2)). Obese, overweight, and normal-weight groups presented a similar lung elastance (median [interquartile range], respectively: 17.7 [14.2-24.8], 20.9 [16.1-30.2], and 20.5 [15.2-23.6] cm H2O litre(-1) at 5 cm H2O of PEEP and 19.3 [15.5-26.3], 21.1 [17.4-29.2], and 17.1 [13.4-20.4] cm H2O litre(-1) at 15 cm H2O of PEEP) and chest elastance (respectively: 4.9 [3.1-8.8], 5.9 [3.8-8.7], and 7.8 [3.9-9.8] cm H2O litre(-1) at 5 cm H2O of PEEP and 6.5 [4.5-9.6], 6.6 [4.2-9.2], and 4.9 [2.4-7.6] cm H2O litre(-1) at 15 cm H2O of PEEP). Lung recruitability was not affected by the body weight (15.6 [6.3-23.4], 15.7 [9.8-22.2], and 11.3 [6.2-15.6]% for normal-weight, overweight, and obese groups, respectively). Lung gas volume was significantly lower whereas total superimposed pressure was significantly higher in the obese compared with the normal-weight group (1148 [680-1815] vs 827 [686-1213] ml and 17.4 [15.8-19.3] vs 19.3 [18.6-21.7] cm H2O, respectively). CONCLUSIONS: Obese ARDS patients do not present higher chest wall elastance and lung recruitability.

[Treatment of acute renal failure in Germany: Analysis of current practice]. / Versorgung des akuten Nierenversagens auf deutschen Intensivstationen: Analyse der aktuellen Behandlungspraxis.

BACKGROUND AND OBJECTIVES: There are currently no reliable data on the differential use of renal replacement therapy (RRT) options for critically ill patients with acute renal failure in Germany. PATIENTS AND METHODS: A questionnaire-based survey was delivered to 2265 German intensive care units. The questionnaire contained 19 questions regarding RRT. RESULTS: A total of 423 German intensive care units participated in the survey. The offered modalities of RRT varied significantly: the smaller the facility, the fewer different RRT options were available. Intermittent dialysis procedures were available in only 35% of hospitals with up to 400 beds. In university hospitals, hemodynamically unstable patients were exclusively treated by continuous RRT, whereas in hospitals with up to 400 beds, intermittent RRT was also used. In addition, treatment practice was also dependent on the specialization of the treating physicians: Isolated acute renal failure was treated more often intermittently by nephrologists compared to anesthesiologists (79.7 vs. 43.3%). Nephrologists also used extracorporeal RRT more often in cardiorenal syndrome (54.3 vs. 35.8%), whereas anesthesiologists preferred them in sepsis (37.3 vs. 23.1%). The choice of anticoagulant varied as well: Hospitals with up to 400 beds offered regional citrate anticoagulation in only 50% compared to 90% of university hospitals. CONCLUSIONS: Currently, RRT treatment in acute renal failure on German intensive care units seems to be dependent on the size, local structures, and education of the intensivists rather than patient needs. Our results demonstrate the necessity to establish cross-disciplinary standards for the treatment of acute renal failure in German intensive care units.