Читать книгу 40 Years of Continuous Renal Replacement Therapy - Группа авторов - Страница 21

The 17th Acute Disease Quality Initiative consensus conference held in Asiago during the period June 10–13, 2016, set the stage for the most important required innovation in CRRT technology and the most important recent developments in this field [31].

First of all there was a call to action inviting all experts and manufacturers in the field of CRRT technology to utilize a standardized nomenclature [32–34]. This is considered the fundamental starting point to generate common knowledge and to advance in a homogeneous environment.

The consensus group focused on future technological needs and expected advances, pointing out the desirable characteristics of new equipment and membranes, and the importance of integration of information technology in the process of patient care and decision making. Some conclusions were made based on current available evidence and some statements were mostly based on expert opinion and a proposed future research agenda [35].

Throughout AKI management, technology is involved at different levels and contributes to improve practice and patient outcomes by supporting prescription and delivery of CRRT (Fig. 2).

AKI management is a continuum from detection to treatment, which must include continuous reevaluation of treatment prescription and delivery. The use of modern information technology tools was recommended to improve practice and patient care. The process of patient evaluation and identification of therapy targets should lead to a “precision” (personalized) prescription according to patient needs and desired physiological targets. The concept of a gap between capacity (of the native organ) and (metabolic) demand is emerging as an important element to prescribe personalized therapy. In the process of dynamic prescription (frequently adjusted on the basis of actual delivery results), full-treatment reassessment should be made at least every 6 h while dedicated equipment (CRRT machines) should be used to deliver specific techniques. Adoptive technologies should be avoided. When prescribing CRRT, availability, training, and environmental and staffing issues should be considered, and prescription should be made according to local conditions and usage. Several technological tools have been developed to monitor target achievement and to suggest modifications in prescription. Manual, authorized, or automatic feedback technology is now available in chronic dialysis machines and it should be promoted in future CRRT machines. Integration of patient and machine signals through information technology tools and connectivity with EMR and data collection systems will be required to allow pragmatic trials and to make big data registries available for analysis. Data can then be used for QA and CQI purposes in the center, in the region, and even in multinational data collection studies.

Different surface and structure modifications have been introduced on new membranes to increase biocompatibility, reduce thrombogenicity, and to modify sieving and adsorption properties. Surface functionalization has also been attempted as in the case of vitamin E-bound membranes, where α-tocopherol has been covalently bound to a polysulfone membrane to reduce oxidant species generation and oxidant stress, to prevent or treat ischemia-reperfusion injury, and to improve the inflammatory pattern in sepsis [36]. These membranes should be further investigated.

The nature of the critically ill patient requires a continuous control of CRRT delivery and strict adherence to prescription, as well as maximization of patient tolerance. The treatment should avoid sudden and sharp variations of physiological parameters, and allow slow and precise correction of fluid, electrolyte, and metabolic imbalances. To prevent complications, the systems currently used in chronic dialysis for online intradialytic monitoring continuously measure various hemodynamic and biochemical parameters. Such online monitoring systems are particularly useful in short intermittent dialysis techniques, where the risk of “unphysiology” is greater due to the high efficiency of the treatment. The development of such systems is based on a 3-step analysis that can be summarized as follows: (1) Each patient is different (this requires precision CRRT and personalized prescription). (2) Patient characteristics vary during treatment (this requires that dynamic prescription also changes over time). A solution to this problem has been attempted with the use of preset profiles of ultrafiltration and dialysate composition, but instead of being based on actual signals from the patient, the profiles are blind to the patient needs and outcomes. (3) Patient and machine signals, describing actual clinical and technical conditions, should be used to drive the delivery of therapy and to reassess prescription (today, this is possible through multi-input/multi-output controllers and actuators, which constitute the basis of a “smart” biofeedback).

In CRRT, patient and machine data collection should also feed into electronic medical records. Data should be used immediately to fulfill specific objectives:

•Achievement of an adequate ultrafiltration rate and profile over time, optimizing fluid balance (with minimal deviations from prescribed values) and cardiovascular response to fluid withdrawal while ensuring maximal hemodynamic stability. This is possible through the integration of bioimpedance and online hematocrit measurements resulting in important input on overall patient fluid status and actual circulating blood volume changes. Maintenance of hemodynamic stability and smooth operation of the CRRT machines with minimal interruptions will result in a more effective delivery of the treatment prescribed.

•Adequate dose delivery with minimal deviations from prescribed values. This can be achieved in different ways depending on hardware and software integration.

•Thermal and energy balance with biofeedback-driven temperature control. This feedback can be designed to achieve a specific energy balance (KJ/h) or a target temperature control by adjusting dialysate or replacement fluid temperature according to signals originating from temperature sensors placed on blood and dialysate lines. It should be remembered that significant heat loss can occur when the extracorporeal circuit is exposed to room temperature.

•Circuit pressure control. This automatic feedback should provide the best blood flow adjustment to pressure variations measured within the circuit. This would help clinicians to deal with a malfunctioning catheter and provide early warning of access malfunction, a very common cause of inappropriate treatment delivery.

•Acid-base and electrolyte control could be achieved via a biochemical feedback based on on-line chemical sensors and actuators operating on a variable concentration of dialysate and replacement solution or modification of flow rate of the solutions.

The use of currently available measurement devices is strongly recommended, as well as the development of new “sensors” for continuous monitoring during the CRRT session. Such devices should be simple, noninvasive, cheap, possibly integrated with the machine, sterile, biocompatible if they come in direct contact with blood, integrated with an external EMR and potentially linked to automatic actuators, and low cost.