Lung (extracorporeal CO2 removal) and renal (continuous renal replacement therapy) support: the role of ultraprotective strategy in Covid 19 and non-Covid 19 ARDS. A case-control study.

BACKGROUND: Preliminary studies suggest that moderate ARDS and acute renal failure might benefit from extracorporeal CO2 removal (ECCO2R) coupled with CRRT. However, evidence is limited and potential for this coupled treatment may need to be explored. The aim of the present study was to evaluate whether a protective driving pressure was obtained applying low-flow ECCO2-R plus CRRT in patients affected by moderate ARDS with COVID-19 compared to an historical group without COVID-19. METHODS: A case-control study has been conducted comparing a group of consecutive moderate ARDS patients presenting AKI and affected by COVID-19, who needed low-flow ECCO2-R plus CRRT to achieve an ultra-protective ventilatory strategy, with historical group without COVID-19 that matched for clinical presentation and underwent the same ultra-protective treatment. VT was set at 6 mL/kg predicted body weight then ECCO2R was assessed to facilitate ultra-protective low VT ventilation to preserve safe Pplat and low driving pressure. RESULTS: ECCO2R+CRRT reduced the driving pressure from 17 (14-18) to 11.5 (10-15) cmH2O (p<0.0004) in the fourteen ARDS patients by decreasing VT from 6.7 ml/kg PBW (6.1-6.9) to 5.1 (4.2-5.6) after 1 hour (p <0.0001). In the ARDS patients with COVID-19, the driving pressure reduction was more effective from baseline 18 (14-24) cmH2O to 11 (10-15) cmH2O (p<0.004), compared to the control group from 15 (13-17) to 12(10-16) cmH2O (p< 0.03), after one hour. ECCO2R+CRRT did not affected 28 days mortality in the two groups, while we observed a shorter duration of mechanical ventilation (19 {7-29} vs 24 {22-38} days; p=0.24) and ICU length of stay (19 {7-29} vs 24 {22-78} days; p=0.25) in moderate ARDS patients with COVID-19 compared to control group. CONCLUSIONS: In moderate ARDS patients with or without COVID-19 disease, ECCO2R+CRRT may be and effective supportive treatment to reach protective values of driving pressure unless severe oxygenation defects arise requiring ECMO therapy initiation.

Olfactory recovery following omicron variant infection: a psychophysical prospective case-control study with six-month follow up.

OBJECTIVE: This study aimed to evaluate the recovery of olfactory function at six months in individuals infected with the coronavirus disease 2019 omicron variant, using psychophysical tests. METHODS: A prospective case-control study that included severe acute respiratory syndrome coronavirus-2 patients infected in February and March 2022 was conducted. Patients underwent the Sniffin' Sticks test within 10 days of infection and again after at least 6 months. The olfactory scores were compared with those of a control group. RESULTS: In all, 102 patients and 120 controls were enrolled in the study. At baseline, 26 patients (25.5 per cent) self-reported smell loss. The median threshold, discrimination and identification score was 33.6 (interquartile range, 12.5) for the cases and 36.5 (interquartile range, 4.38) for the controls (p < 0.001). Based on the threshold, discrimination and identification scores, 12 controls and 34 patients reported olfactory dysfunction (p < 0.001). Eighty cases underwent re-evaluation at six months; the median threshold, discrimination and identification score was 37.1 (interquartile range, 4.75) with no significant differences compared with the controls. CONCLUSION: Six months after infection, the prevalence of olfactory dysfunction in patients did not differ significantly from the control population.

Extracorporeal CO 2 Removal During Renal Replacement Therapy to Allow Lung-Protective Ventilation in Patients With COVID-19-Associated Acute Respiratory Distress Syndrome.

The aim of this retrospective multicenter observational study is to test the feasibility and safety of a combined extracorporeal CO 2 removal (ECCO 2 R) plus renal replacement therapy (RRT) system to use an ultraprotective ventilator setting while maintaining (1) an effective support of renal function and (2) values of pH within the physiologic limits in a cohort of coronavirus infectious disease 2019 (COVID-19) patients. Among COVID-19 patients admitted to the intensive care unit of 9 participating hospitals, 27 patients with acute respiratory distress syndrome (ARDS) and acute kidney injury (AKI) requiring invasive mechanical ventilation undergoing ECCO 2 R-plus-RRT treatment were included in the analysis. The treatment allowed to reduce V T from 6.0 ± 0.6 mL/kg at baseline to 4.8 ± 0.8, 4.6 ± 1.0, and 4.3 ± 0.3 mL/kg, driving pressure (ΔP) from 19.8 ± 2.5 cm H 2 O to 14.8 ± 3.6, 14.38 ± 4.1 and 10.2 ± 1.6 cm H 2 O after 24 hours, 48 hours, and at discontinuation of ECCO 2 R-plus-RRT (T3), respectively ( p < 0.001). PaCO 2 and pH remained stable. Plasma creatinine decreased over the study period from 3.30 ± 1.27 to 1.90 ± 1.30 and 1.27 ± 0.90 mg/dL after 24 and 48 hours of treatment, respectively ( p < 0.01). No patient-related events associated with the extracorporeal system were reported. These data show that in patients with COVID-19-induced ARDS and AKI, ECCO 2 R-plus-RRT is effective in allowing ultraprotective ventilator settings while maintaining an effective support of renal function and values of pH within physiologic limits.

Initial setting of high-flow nasal oxygen post extubation based on mean inspiratory flow during a spontaneous breathing trial.

PURPOSE: High flow nasal cannula (HFNC) is commonly used post-extubation in intensive care (ICU). Patients' comfort during HFNC is affected by flow rate. The study aims to describe the relationship between pre-extubation inspiratory flow requirements and the post-extubation flow rates on HFNC that maximises patient's comfort. METHODS: This was an observational, retrospective study conducted in a university-affiliated ICU. We included patients extubated following successful spontaneous breathing trial (SBT). During the SBT we recorded variables including inspiratory flow. Patients who passed the SBT were extubated onto HFNC. HFNC was titrated from 20 L/min and increased in steps of 10 L/min, up to 60 L/min. At each step, patient's level of comfort was assessed. Fraction of inspired oxygen was titrated to maintain oxygen saturation 92-97%. RESULTS: Nineteen participants were enrolled in the study. There was a significant positive correlation between mean inspiratory flow pre-extubation and the flow setting on HFNC which achieved the best comfort post-extubation (r2 0.88; p < 0.001). Overall, greatest comfort was observed for HFNC flows between 30 and 40 L/min but with individual variability. CONCLUSION: Measuring mean inspiratory flow during an SBT allows for individualised setting of HFNC flow rate immediately post-extubation and achieves the greatest comfort and interface tolerance.

Occurrence of ventilator associated pneumonia using a tracheostomy tube with subglottic secretion drainage.

BACKGROUND: Ventilator-associated pneumonia (VAP) is a significant cause of morbidity and mortality in critically ill patients who require mechanical ventilation (MV). Subglottic secretions above the endotracheal cuff are associated with bacteria colonization of lower respiratory tract, causing VAP. A preventive strategy to avoid subglottic secretion progression is the drainage with special tracheal tubes effective in preventing both early onset and late onset VAP. The purpose of this study was to measure VAP incidence in tracheostomized patients with suction above the cuff. METHODS: The authors performed a matched cohort study with historical control in three academic Intensive Care Units (ICUs): upon ICU admission, patients requiring MV were submitted to tracheostomy with a tracheal tube allowing drainage of subglottic secretions (treatment group). A control group without suctioning above the cuff was selected applying the propensity score matching on dataset of previous ELT Study. VAP occurrence at 28-days from intubation was the primary endpoint; hospital mortality and ICU-free days at 28-days were the secondary endpoints. RESULTS: Between July 2014 and April 2016, 125 tracheostomized patients were included in the analysis. 232 tracheostomized patients without suctioning were selected as a control group for the matched cohort study. The application of propensity score matching selected 60 patients to compare the two groups. Incidence of VAP was 8% in treatment group and 19.4% in the control group (P value =0.004). After balance with propensity score matching VAP was 8.3% and 21.7% (P value =0.0408), respectively. CONCLUSIONS: Subglottic secretion drainage reduces incidence of VAP in critically ill patients requiring ongoing MV via tracheostomy.