40 Years of Continuous Renal Replacement Therapy. Группа авторов

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СКАЧАТЬ 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.

      CRRT Connectivity

      All the data that are continuously generated by the patient and machine during treatment must be collected. While automatic feeding of patient data into the EMR is important for clinical purposes, data collection from CRRT machines is crucial both for technical and clinical purposes.

      Machine connectivity can be provided via different tools. Machine and patient chip cards can be used to extract data from single treatments from the front-end terminal (CRRT machine). Cable or wireless connectivity may permit the download of technical and clinical parameters from single or multiple machines to analyze single treatment data as well as trends or statistics in multiple treatments. Cloud-based connectivity could help clinicians to generate virtual registries and analyze single treatments or center performance in absolute terms or relative to other units. This may result in important feedback to clinicians to either strictly control outliers or to change policies and procedures in case of repeatedly unsatisfactory results.

      Data collected and stored in EMRs may be rapidly evaluated and managed by ad hoc designed electronic sniffers, which may alert clinicians about dangerous trends or unwanted effects of CRRT. Solutions to the problem may be listed as suggestions or may be even automatically fed back into devices such as pumps and CRRT machines. The feedback may either require manual application of the necessary change by a nurse/physician or authorization of an operational change proposed by the system, or it may operate automatically.

      Specific Technology for Small Infants and Pediatric Applications

The requirement for specific technology in the field of pediatric CRRT emerged in the early 1980s [37]. More recently, new developments have led to the utilization of a miniaturized CRRT machine called Cardio-Renal Pediatric Dialysis Emergency Machine for the treatment of AKI in neonates and small children (Fig. 3) [4, 38]. There is a general consensus that specific technology should be used for such a small number of patients with peculiar characteristics and requirements.

Fig. 3. The new Cardio-Renal Pediatric Dialysis Emergency Machine (CARPEDIEM) for continuous RRT (CRRT) in neonates and small children.

      Conclusions

      Over the last 40 years, CRRT has been widely utilized for the management of AKI in critically ill patients and it has greatly benefited from important technological advances in machine design and the application of novel, more complex modalities that have greatly expanded the field of extracorporeal therapies in the intensive care unit. Concurrently, the treatment of the AKI patient has evolved from the single replacement of kidney function to the support of the patient as a whole (multiple organ support therapy), incorporating technologies that assist in the management of multiple organ dysfunctions. Necessarily, such integrated care must be supported by information technologies, which assist in data collection and integration, delivery of personalized prescriptions, and measurement of results. Such technologies will allow the prescription and delivery of precision CRRT, and will contribute to the improvement of patient care.

A significant number of advances have taken place since the beginning of CRRT. Progress has been made in technology as well as in the understanding of AKI. New biomaterials and new devices are now available and new frontiers are on the horizon. The evolution of technology in critical care nephrology and CRRT has been enormous and further evolution is expected in the future. The final target is the improvement of patient care and amelioration of clinical outcomes [40–45].

      References

1Ronco C: Critical care nephrology: the journey has begun. Int J СКАЧАТЬ