ABSTRACT
Background: Dialysis treatment in chronic obstructive pulmonary disease (COPD) patients is a challenging setting: COPD frequently develop hypercapnia due to presence of CO2 that originates from the reaction between acetic/citric acid with bicarbonate, needed to prevent the precipitation of salts inside. Carbon dioxide passes through the dialysis membrane by diffusion, because of the significant difference in partial pressure between the dialysate compartment (80-100 mmHg) and the blood compartment (35-45 mmHg) thus determining CO2 overload. A COPD patient, on the other hand, may not be able to implement effective respiratory compensation mechanisms with the consequent onset of hypercapnia. Method(s): A 79-year-old ESRD patient was admitted because of SARS-CoV2 infection. His medical history was notable for emphysematous COPD with predominantly severe obstructive disorder on chronic oxygen therapy. The patient present acute hypercapnic dyspnea during the first dialysis session in COVID19 setting with severe desaturation episode associated with mixed acidosis (pH 7.13, pCO2 83 mmHg, HCO3- 22.7 mmol/l). The raise of pCO2 was remarkable, in fact partial pressure of CO2 (pCO2) was 61 mmHg before dialysis versus pCO2 83 mmHg after dialysis treatment (Fig.1). The patient appeared comatose and poorly responsive to stimuli. CPAP cycle was set up and he was placed in semi-orthopneic decubitus did not improve the clinical conditions. To prevent the hypercapnia condition Acetate Free Biofiltration (AFB) technique with profiled potassium (K+ 3.5 mmol/L) was prescribed. The vital parameters during this hemodialysis session remained stationary and the pCO2 values at the end of dialysis were comparable to those at the beginning of dialysis (pCO2 65 mmHg versus a.d. pCO2 63 mmHg) (Fig. 1). The following treatment were well tolerated with progressive improvement of respiratory parameters. Result(s): The AFB technique is characterized by a dialysate without buffers which do not react and do not produce carbon dioxide. The correction of the acid-base balance takes place with the post-dilution infusion of a sterile solution of sodium bicarbonate (NaHCO3). Furthermore, the absence of acetic acid avoids the stimulation of interleukin 1beta (IL-1beta) and of the Tumor Necrosis Factor alpha (TNFalpha) which in turn would have activated the enzyme Nitric Oxide Synthetase (iNOS) thus causing an increased production of Nitric Oxide (NO) and a consequent greater hemodynamic instability. AFB is therefore a more tolerated technique from a hemodynamic point of view. Conclusion(s): This case report has shown that AFB is an effective hemodialysis technique in preventing a condition of hypercapnia in patients suffering from respiratory diseases (Fig.2). The patient also experienced hemodynamic stability from the AFB with no longer presenting significant hypotensive episodes.
ABSTRACT
BACKGROUND AND AIMS: High flux haemodialysis membranes may modulate the cytokine storm of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but their impact in chronic haemodialysis (CHD) patients is not assessed [1, 2]. The aim of the study was the evaluation of asymmetric cellulose triacetate (ATA) and polymethylmethacrylate (PMMA) dialyzers on inflammatory markers in CHD patients with SARS-CoV-2. METHOD: A prospective, observational study on CHD patients (age ≥18 years) affected by SARS-CoV-2 was carried out. Patients were enrolled from March 2020 to May 2021 and dialysis was performed at S. Orsola University Hospital (Bologna, Italy) Dialysis Unit. Mechanical ventilation at diagnosis was exclusion criteria. Pre-and post-dialysis C-reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6) were determined at each session and corrected for haemoconcentration during the complete SARS-CoV-2 period. Patients who underwent online haemodiafiltration (OLHDF) with PMMA dialyzer (Filtryzer BG-UTM, Toray, surface area 2.1 m2, cut-off 20 kDa, KUF 43 mL/h/mmHg) were compared with those who underwent OLHDF with ATA dialyzer (SolaceaTM, Nipro, surface area 2.1 m2, cut-off 45 kDa, KUF 72 mL/h/mmHg). The primary endpoint was to assess the differences in the reduction ratio/session (RR) of CRP, PCT and IL-6. RESULTS: A total of 74 patients were enrolled, 48 were treated with ATA and 26 were with PMMA (420 versus 191 dialysis sessions). The main results are shown in Table 1. Median IL-6RR% was higher for ATA [17.08%, interquartile range (IQR) -9.0 to 40.0 versus 2.95%, IQR -34.63 to 27.32]. CRP and PCT showed higher RR with ATA in comparison to PMMA. When IL-6RR > 25% was the dependent variable in the multiple logistic regression analysis only ATA showed a significant correlation [odds ratio (OR) 1.891, 95% confidence interval (95% CI) 1.273-2.840, P = .0018) while higher CRP favoured the risk of lower IL6RR (OR 0.9101, 95% CI 0.868-0.949, P < 0.0001) (Table 2). CONCLUSION: In SARS-CoV-2 CHD patients treated with OLHDF, ATA showed a better anti-inflammatory profile than PMMA, in particular regarding IL-6 RR.
ABSTRACT
BACKGROUND AND AIMS: Several chronic medical conditions appear to increase the risk of severe COVID-19. Chronic kidney disease (CKD) patients have a high risk of symptomatic infection and severe respiratory symptoms because of chronic inflammation, uremic toxins accumulation, endothelial dysfunction and an impaired immune response. Even though the presence of one or more comorbidities increases the risk of mortality, information of the outcome of COVID-19 in CKD patients is not yet available. The aim of the study is to present the incidence and outcome of COVID- 19 in patients referring to our Nephrology Unit considering CKD patients, dialysis patients and kidney transplant recipients. METHOD: This study is prospective single centre carried out considering patients referring to the Nephrology Unit of St. Orsola University Hospital in Bologna with COVID 19 diagnosis from 15THMarch to 30THMay 2020. RESULTS: Our cohort included 52 patients admitted to our Nephrology Unit because of Sars Cov2 infection confirmed by positive reverse transcriptase polymerase chain reaction on nasopharyngeal swab. The mean age was 67.2 6 13.8 years (range, 33-88 years). Demographic, clinical and radiological features in Table 1. Forty-eight patients (92.3%) underwent chest TC. The main findings were: several bilateral interstitial pneumonia (39 patients, 81.2%), monolateral peripheral ground-glass opacities (6 patients, 12.5%), no signs of pneumonia (3 patients, 6.2 %). Clinical course is highly variable: 18 patients (34.6 %) were asymptomatic, 23 patients (44 %) had a mild course requiring low flux oxygen therapy and 11 patients (21%) presented severe pneumonia and respiratory distress that requires ventilatory support in intensive care unit. Forty patients (70%) had hydroxychloroquine-azithromycin dual therapy, 3 patients (6%) had antiviral therapy in addiction. Sixteen patients (31%) with P/F <150 mmHg were treated with Tocilizumab. Heparin Therapy, to prevent the thromboembolic risk of Sars-Cov2 infection, was administered according to the body weight in forty patients (70%);, but not in patients in warfarin therapy (12 patients, 30%). Twenty-six patients (50%) needed antibiotics for bacterial infections combined to the Sars-Cov2 infection. Steroid therapy was added in 40% of cases. The average time of negativization for Sars Cov2, tested with two nasopharyngeal swab specimens made seven days apart, was 31615 day. Fifty-one patients, 98% of diagnosed cases, required hospitalization with an average stay of 35±26 days. Thirty patients (25%) died. Mean age of non-survivors was 72±11years while mean age of survivors was 64±11years. No differences in preexisting comorbidities were observed between survivors and non survivors;oxygen saturation on presentation was statistically lower in non survivors. CONCLUSION: CKD is an independent risk factor for COVID-19 associated inhospital mortality. The mortality rate (25%), much higher than in general population (1.8-8%) may be explained by the older age of patients and the presence of more pathological conditions, especially cardiovascular disease.