Spallation and particles infusion into the extracorporeal circuit during CRRT: a preventable phenomenon.

Patients in intensive care are exposed to the risk of microparticle infusion via extracorporeal lines and the resulting complications. A possible source of microparticle release could be the extracorporeal circuit used in blood purification techniques, such as continuous renal replacement therapy (CRRT). Disposable components of CRRT circuits, such as replacement bags and circuit tubing, might release microparticles such as salt crystals produced by precipitation in replacement bags and plastic microparticles produced by spallation. In-line filtration has proven effective in retaining microparticles both in in-vitro and in-vivo studies. In our study, we performed an in-vitro model of CRRT-treatment with the aim of detecting the microparticles produced and released into the circuit by means of a qualitative and quantitative analysis, after sampling the replacement and patient lines straddling a series of in-line filters. Working pressures and flows were monitored during the experiment. This study showed that microparticles are indeed produced and released into the CRRT circuit. The inclusion of in-line filters in the replacement lines allows to reduce the burden of microparticles infused into the bloodstream during extracorporeal treatments, reducing the concentration of microparticles from 14 mg/mL pre in-line filter to 11 mg/mL post in-line filter. Particle infusion and related damage must be counted among the pathophysiological mechanisms supporting iatrogenic damage due to artificial cross-talk between organs during CRRT applied to critically ill patients. This damage can be reduced by using in-line filters in the extracorporeal circuit.

Sampling from Extracorporeal Circuit: A Step Forward for Dose Monitoring in Continuous Renal Replacement Therapy.

INTRODUCTION: Continuous renal replacement therapies (CRRTs) require constant monitoring and periodic treatment readjustments, being applied to highly complex patients, with rapidly changing clinical needs. To promote precision medicine in the field of renal replacement therapy and encourage dynamic prescription, the Acute Dialysis Quality Initiative (ADQI) recommends periodically measuring the solutes extracorporeal clearance with the aim of assessing the current treatment delivery and the gap from the therapeutic prescription (often intended as effluent dose). To perform this procedure, it is therefore necessary to obtain blood and effluent samples from the extracorporeal circuit to measure the concentrations of a target solute (usually represented by urea) in prefilter, postfilter, and effluent lines. However, samples must be collected simultaneously from the extracorporeal circuit ports, with the same suction flow at an unknown rate. METHODS: The proposed study takes the first step toward identifying the technical factors that should be considered in determining the optimal suction rate to collect samples from the extracorporeal circuit to measure the extracorporeal clearance for a specific solute. RESULTS: The results obtained identify the low suction rate (i.e., 1 mL/min) as an ideal parameter for an adequate sampling method. Low velocities do not perturb the external circulation system and ensure stability prevailing pressures in the circuit. Higher velocities can be performed only with blood flows above 120 mL/min preferably in conditions of appropriate filtration fraction. DISCUSSION/CONCLUSIONS: The specific value of aspiration flow rate must be proportioned to the prescription of CRRT treatments set by the clinician.

Perioperative use of serum creatinine and postoperative acute kidney injury: a single-centre, observational retrospective study to explore physicians' perception and practice.

BACKGROUND: Postoperative acute kidney injury (PO-AKI) is a leading cause of short- and long-term morbidity and mortality, as well as progression to chronic kidney disease (CKD). The aim of this study was to explore the physicians' attitude toward the use of perioperative serum creatinine (sCr) for the identification of patients at risk for PO-AKI and long-term CKD. We also evaluated the incidence and risk factors associated with PO-AKI and renal function deterioration in patients undergoing major surgery for malignant disease. METHODS: Adult oncological patients who underwent major abdominal surgery from November 2016 to February 2017 were considered for this single-centre, observational retrospective study. Routinely available sCr values were used to define AKI in the first three postoperative days. Long-term kidney dysfunction (LT-KDys) was defined as a reduction in the estimated glomerular filtration rate by more than 10 ml/min/m2 at 12 months postoperatively. A questionnaire was administered to 125 physicians caring for the enrolled patients to collect information on local attitudes regarding the use of sCr perioperatively and its relationship with PO-AKI. RESULTS: A total of 423 patients were observed. sCr was not available in 59 patients (13.9%); the remaining 364 (86.1%) had at least one sCr value measured to allow for detection of postoperative kidney impairment. Among these, PO-AKI was diagnosed in 8.2% of cases. Of the 334 patients who had a sCr result available at 12-month follow-up, 56 (16.8%) developed LT-KDys. Data on long-term kidney function were not available for 21% of patients. Interestingly, 33 of 423 patients (7.8%) did not have a sCr result available in the immediate postoperative period or long term. All the physicians who participated in the survey (83 out of 125) recognised that postoperative assessment of sCr is required after major oncological abdominal surgery, particularly in those patients at high risk for PO-AKI and LT-KDys. CONCLUSION: PO-AKI after major surgery for malignant disease is common, but clinical practice of measuring sCr is variable. As a result, the exact incidence of PO-AKI and long-term renal prognosis are unclear, including in high-risk patients. TRIAL REGISTRATION: ClinicalTrials.gov , NCT04341974 .

Effects of psychological interventions on anxiety and pain in patients undergoing major elective abdominal surgery: a systematic review.

A maladaptive response to surgical stress might lead to postoperative complications. A multidisciplinary approach aimed at controlling the surgical stress response may reduce procedural complications and improve patients' quality of life in the short and long term. Several studies suggest that psychological interventions may interact with the pathophysiology of surgical stress response, potentially influencing wound repair, innate and adaptive immunity, inflammation, perception of pain, and patients' mood. The aim of this systematic review is to summarise the effects of perioperative psychological interventions on surgical pain and/or anxiety in adult patients scheduled for elective general abdominal and/or urologic surgery.We conducted a systematic review of controlled clinical trials and observational studies involving psychological interventions for adult patients scheduled for elective general abdominal and/or urologic surgery. Only studies reporting pain and/or anxiety among outcome measures were included in the systematic review. The following psychological interventions were considered: (1) relaxation techniques, (2) cognitive-behavioural therapies, (3) mindfulness, (4) narrative medicine, (5) hypnosis and (6) coping strategies.We examined 2174 papers. Among these, 9 studies were considered eligible for inclusion in this systematic review (1126 patients cumulatively): 8 are randomised controlled trials and 1 is an observational prospective pre/post study.Psychological characteristics widely influence the pathophysiological mechanisms underlying the neuroendocrine and inflammatory response to surgical stress, potentially interfering with surgical outcomes. Psychological interventions are technically feasible and realistically applicable perioperatively during abdominal and/or urologic surgery; they influence the pathophysiological mechanisms underlying maladaptive surgical stress response and might have positive effects on patients' surgical outcomes, such as pain and anxiety.

Use of Fluoride as a Marker Solute to Quantify the Current Effective Delivered Dose in Continuous Renal Replacement Therapy: An "in vitro" Study.

BACKGROUND: The current effective delivered dose is a quality indicator for continuous renal replacement therapy. Its periodic assessment might enable physicians to deliver personalised treatments. Yet, its quantification as by extracorporeal urea clearance (Cl) is cumbersome and thus often neglected in routine practice. The aim of this in vitro study is to demonstrate the non-inferior effectiveness of assessing the current effective delivered dose using a simpler, cheaper and faster approach based on measurement of fluoride rather than urea extracorporeal Cl. METHODS: We compared urea and fluoride removal in 3 post-dilution continuous veno-venous haemofiltration (CVVH) and 3 continuous veno-venous haemodialysis (CVVHD) in vitro experimental models. Experiments ran for 180 min, using 3 L of human blood, heparin anticoagulation and a machine dose of 30 mL/kg/h. Urea and fluoride were measured in the inflow, outflow and effluent lines to compare sieving coefficients (SC), saturation coefficients (SA) and transmembrane Cls. RESULTS: In CVVH, the median SC values were 1.06 (1.02-1.07) and 1.02 (1.01-1.04) for fluoride and urea, respectively (discrepancy of 4.3%), while transmembrane convective Cls were 31.28 (30.01-31.31) mL/kg/h and 30.30 (29-31.85) mL/kg/h (discrepancy of 3.13%), respectively. In CVVHD, the median SA values were 1.01 (0.96-1.02) and 1 (0.95-1.01) for fluoride and urea, respectively (discrepancy of 1.6%), while transmembrane dialytic Cls were 30.26 (29.52-31.32) mL/kg/h and 31.16 (30-31.75) mL/kg/h (discrepancy of -2.97%), respectively. CONCLUSION: Fluoride transmembrane removal was close to that observed with urea, in terms of SC, SA and transmembrane Cl. Fluoride seems as much accurate as urea in assessing the current effective delivered dose during both CVVH and CVVHD and might therefore be adopted for dose measurement. Besides accuracy, fluoride bedside assessment could present many advantages over urea, particularly in terms of availability, costs, time requirement and rapidity of assessment.